Dissertation/Thèse

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2024
Thèses
1
  • LARISSA DE SOUZA SOARES SILVA
  • FORMAL [3+3] CYCLOADDITIONS OF ENAMINONES: SYNTHESIS AND REACTIVITY OF POLY-SUBSTITUTED CYCLOHEXENONES

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • AMENSON TRINDADE GOMES
  • ANDRE ALEXANDRE VIEIRA
  • CALINE GOMES FERRAZ
  • JORGE MAURICIO DAVID
  • MAURICIO MORAES VICTOR
  • RODRIGO DE PAULA
  • RONAN BATISTA
  • SABRINA TEIXEIRA MARTINEZ
  • SILVIO DO DESTERRO CUNHA
  • VANDERLUCIA FONSECA DE PAULA
  • Data: 6 févr. 2024


  • Afficher le Résumé
  • The cyclohexenone nucleus is present in several natural products with
    biological activity, is of great synthetic relevance. However, methods
    Traditional synthesis methods have disadvantages, such as synthetic steps
    excessive amounts, use of expensive catalysts and difficulties in obtaining
    substrates. In this work, the study of the reactivity of acids was carried out
    carboxy-3-coumarins against secondary acyclic enaminones, using
    microwaves in formal [3 +3] cycloaddition reactions. The results revealed
    an unprecedented pattern of reactivity, resulting in the formation of a mixture of
    products containing cyclohexenones and amides in different proportions, with
    yields ranging between 2% and 82%. It is worth highlighting the achievement of four
    novel cyclohexenones and the synthesis of amides under mild conditions,
    eliminating the use of catalysts. Furthermore, the application of
    synthesis of cyclohexenones in microwaves, culminating in obtaining a
    new cyclohexenone molecule with a substitution pattern distinct from that of
    cyclohexenone reagent. This result was achieved through a reaction
    of Krapcho decarboxylation catalyzed by boron trifluoride in methanol.

2
  • RAIANA WILSA LINHARES OLIVEIRA
  • Catalytic reduction of nitroaromatics over biomass-derived magnetic catalysts prepared by the combustion method

  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • LUCIANA ALMEIDA DA SILVA
  • MAURICIO BRANDAO DOS SANTOS
  • RODRIGO DE PAULA
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 23 févr. 2024


  • Afficher le Résumé
  • The class of nitroaromatics are among the most frequently detected pollutants in water bodies and effluents, as they provide raw materials for various industrial and agricultural sectors. They are highly toxic, even in low concentrations and have high stability, which ends up hindering biological degradation processes.The main route to attenuating the concentration of these species is catalytic reduction assisted by sodium borohydride with the formation of functionalized amines that serve as raw material for products such as paracetamol, one of the most used drugs worldwide. Associated with this problem, Brazil discards around 7 to 10 tons of cocoa shells annually. Biomasses like this are often associated with application as biosorbents and as catalytic supports in the degradation of species such as nitroaromatics, since they have matrices rich in cellulose, hemicellulose and lignin. The class of magnetic catalysts has an advantage over the others, as they are easily separated from a system only with the help of an external magnetic field. The preference for using iron oxides in the magnetization stage of the biocomposite takes into account their biodegradability, low toxicity and high magnetic potential. An alternative synthesis method that has shown promise is the combustion method, as it is carried out in a single step, is low-cost, self-sustainable, and generates products with interesting characteristics. The catalysts obtained without fuel in the synthesis process obtained better conversion results for 2,4,6-trinitrophenol (2,4,6-TNP) and 3-nitrophenol (3-NP), with values above 90%,while those obtained under stoichiometric conditions obtained better results for the reduction of 4-nitrophenol (4-NP), with values in the same dimension.The reaction rate constants were obtained from the slope values of the pseudo-first order kinetic curves, with values reaching the order of 10-2 s-1It was observed that the catalytic activity of the composites is more prominent in reducing 3-NP and 4-NP than when compared to 2,4,6-TNP, which can be easily explained by the chemical structure of the compound.The catalysts underwent recyclability tests, maintaining conversion values after 5 cycles.

3
  • ROMÁRIO DA SILVA RAMOS
  • Reactivity of isatins with 2-aminonaphthoquinones promoted by barbituric acid and derivatives: synthesis and in silico evaluation of analogues of the pentacyclic alkaloid alpkinidine

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • ANDRE ALEXANDRE VIEIRA
  • JORGE MAURICIO DAVID
  • MAURICIO MORAES VICTOR
  • RODRIGO DE PAULA
  • RONAN BATISTA
  • SABRINA TEIXEIRA MARTINEZ
  • SILVIO DO DESTERRO CUNHA
  • VANDERLUCIA FONSECA DE PAULA
  • Data: 29 févr. 2024


  • Afficher le Résumé
  • In this work, the development and optimization of a new synthetic route were carried out to access analogous pentacycles of the alkaloid alpkinidine simply in a single step, without the need for the use of a column for purification or the use of metals as catalysts. Using ethanol, which is non-toxic and renewable, as a solvent. The use of microwaves allowed us to access the alpkinidine analogues containing the ABCD rings of the alkaloid in a reduced time and with moderate to good yields. Nine new analogues were synthesized using five-substituted isatins and N-substituted 2-amino-naphthoquinones as reagents and thiobarbituric acid as the promoter. An in-silico evaluation of the absorption, distribution, metabolism, excretion and toxicity (ADMET) properties of the synthesized analogues was also carried out.

4
  • LORENA DOS SANTOS LOBO
  • ANALYTICAL STRATEGIES FOR DETERMINATION OF Ag, Au, Pd and Pt IN GEOLOGICAL WASTE MATERIAL FROM A COPPER METALLURGY BY ICP-MS

  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MARIA DAS GRACAS ANDRADE KORN
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • TATIANE DE ANDRADE MARANHÃO
  • Data: 1 mars 2024


  • Afficher le Résumé
  • Platinum, palladium, rhodium, ruthenium, iridium and osmium are called precious metals (or noble metals). The natural occurrence of these chemical elements is extremely rare, and the abundance in the Earth's crust compared to other metals is of low concentration. The chemical analysis of geological materials to determine these precious metals has become a fascinating and challenging field of the Analytical Chemistry, due to the particularities in sample preparation and instrumental determination. The challenge becomes even more intriguing due to the financial value added to these metals, which also moves the world market. In this work, an analytical strategy was carried out to determine precious metals (Ag, Au, Pd and Pt) in waste geological material by inductively coupled plasma-mass spectrometry (ICP-MS). Two types of sample preparation were carried out, wet and dry digestion, as a strategy for precise and accurate quantification of these metals. For chemical analysis by ICP-MS, the use of the standard mode (STD) and the mode with kinetic energy discrimination (KED) were tested, where the second mode was efficient for the determinations of Ag, Pd and Pt. To evaluate the accuracy and precision was analyzed concomitantly with the certified reference material (CRM) of concentrated copper ore. The limits of detection (LD) obtained for Ag, Au, Pd and Pt in KED mode were of 1.0; 0.2; 2.0; 11.0 µg kg-1, respectively, and the limits of quantification (LQ) were of 3.0; 1.0; 10.0; 49.0 µg kg-1. Spectral interferences were eliminated with an extraction technique (pre-treatment) by Fire Assay, which generated satisfactory results for determining trace levels of Pd and Pt, mainly. Despite investigation, Au determinations were not satisfactory for accuracy due to non-spectral interferences. The analytical method was applied to four samples of geological waste resulting from the metallurgical process, obtaining results between 8.0 and 156.0 mg kg-1 of silver, 0.20 and 1.30 mg kg-1 of palladium with acid digestion, and, between 0.10 and 0.20 mg kg-1 of platinum with dry digestion. However, the optimized analytical method showed good precision, accuracy, selectivity, and specificity in determining Ag, Pd, and Pt in geological waste samples by ICP-MS, using the KED mode.

5
  • MATHEUS CHAVES MOREIRA DA SILVA
  • Removal of bisphenol-A by H3PO4-activated hydrochar: Thermodynamic description by model comparison, modification and cooperation

  • Leader : RAILDO ALVES FIUZA JUNIOR
  • MEMBRES DE LA BANQUE :
  • ALLISON GONÇALVES SILVA
  • ARTUR JOSE SANTOS MASCARENHAS
  • LUIZA AMIM MERCANTE
  • RAILDO ALVES FIUZA JUNIOR
  • RODRIGO DE PAULA
  • Data: 8 mars 2024


  • Afficher le Résumé
  • Bisphenol-A (BPA) makes up several plastics and is an emerging contaminant: a heterogeneous group of substances that cause adverse effects on human health and the ecosystem in which they are located. Despite their increasing use by society, these pollutants are still poorly monitored and are not completely removed in conventional water and sewage treatment. Adsorptive methods can be used for their removal, such as the use of activated carbon (AC), which can be produced from abundant, cheap and naturally occurring biomass residues. A good example is litter, which is the surface layer of soil composed of organic residues. In this work, mangrove litter was used in the production of activated carbon to be used to remove bisphenol-A. Biomass was characterized by ASTM standard methods, thermogravimetric analysis, and energy-dispersive X-ray spectrometry. The activated carbons were prepared by impregnating the biomass with phosphoric acid, in three different concentrations, in hydrothermal pyrolysis, and were subsequently properly carbonized in dry pyrolysis. The materials produced had their texture analyzed by N2 adsorption, their morphologies were investigated by SEM and surface functional groups by FTIR. The adsorption tests were carried out in Erlenmeyer flasks, shaking in a thermostated shaker and the adsorption test solutions were read by UV-VIS spectroscopy. Biomass showed promise for the development of adsorbent materials, activated carbons obtained specific areas of up to 969 m2 g-1 and the adsorption capacity of bisphenol-A to form a monolayer of 154.33 mg g-1 at 27ºC increased to 178 .39 mg g-1 at 45ºC. Thermodynamic and kinetic studies using FTIR demonstrate that adsorption occurs through hydrogen bonds, in probable synergy with hydrophobic interactions. Thermodynamics, evaluated by a critical comparative and cooperative method of models known in the literature, and a modification proposal, also reveals a practically unchanged spontaneity of adsorption from 27-55°C, with an endothermic reaction and entropy reduction being replaced by an endothermic reaction with entropic increase as temperature increases.

6
  • GABRIEL GOMES LEAL
  • H-BEA TYPE CATALYSTS APPLIED TO GLYCEROLYSIS OF FATTY ACIDS IN THE PRESENCE OF CRUDE GLYCERIN: AN ALTERNATIVE FOR PRE-TREATING ACID RAW MATERIALS FOR BIODIESEL PRODUCTION

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MARCOS MALTA DOS SANTOS
  • MAURICIO BRANDAO DOS SANTOS
  • ROSANGELA REGIA LIMA VIDAL
  • SORAIA TEIXEIRA BRANDAO
  • Data: 22 mars 2024


  • Afficher le Résumé
  • The global energy scenario is dominated by oil and other fossil fuels from limited sources that generate environmental impacts associated with climate change. In this context, biodiesel grows as a renewable and sustainable alternative energy source with properties very similar to petroleum diesel. In the global biodiesel production process, oleaginous raw materials are widely used in the transesterification reaction, producing alkyl esters and large volumes of glycerin as a co-product of the reaction. The search for alternative raw materials is interesting due to the high price of oilseed sources. However, the biggest challenge encountered is the presence of high levels of free fatty acids. Glycerolysis is an esterification reaction in the presence of crude glycerin at high temperatures that can be applied as a pre-treatment step for acidic raw materials. Heterogeneous catalysis appears as a solution to make glycerolysis viable and improve its performance at temperatures below 220 ºC. Among the heterogeneous catalysts, we have zeolites, whose composition, structure and porosity generate interest in their applications in the glycerolysis of fatty acids. In this work, Nickel and Molybdenum were impregnated in beta zeolites, and their performance was evaluated in the glycerolysis reaction of fatty acids under different reaction conditions. The Mo/H-BEA catalyst presented the highest conversion rates among the catalysts evaluated. The best reaction conditions observed were at 120 ºC, oil: glycerin molar ratio 1:2 and 1.0% by catalyst mass. It was observed that the presence of impurities in crude glycerin, such as water, MONG and inorganic salts, affects the reaction.

7
  • NADJA SOUSA DE OLIVEIRA
  • Statistical tools in the development of ultrasound-assisted Pt/Ti catalytic materials for the glycerol electro-oxidation. 
  • Leader : VALERIA CRISTINA FERNANDES
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • RAILDO ALVES FIUZA JUNIOR
  • ROSANGELA REGIA LIMA VIDAL
  • SILVANA MATTEDI E SILVA
  • VALERIA CRISTINA FERNANDES
  • Data: 29 mars 2024


  • Afficher le Résumé
  • Nowadays the demand for alternative sources in substitution of fossil and pollutant energy sources is growing fast. Biodiesel is an important alternative on this scenario with its production increasing each year. This process generates 10 wt% of glycerol as co-product. Since glycerol supply has become higher than its demand in the last decade, research on ways of glycerol valorization have grown markedly, specially through electrocatalytic routes. This work presents a study on the use of chemometric tools and other statistical analyzes to evaluate and improve the conditions of Pt deposition on Ti electrodes using electrochemical techniques. In addition, the catalytic activities toward glycerol electrooxidation on the different electrodeposits obtained were examined by cyclic voltammetry and chronoamperometry in acid media. A 23 factorial design was used, where the parameters chosen were: number of deposition cycles (NDC – 40 and 60 cycles), scan rate (SR – 100 and 200 mV s-1 ) and presence and absence of ultrasound (US, 100 W). The electrochemically active surface area (ECSA) was used as response.  The X-ray diffraction peaks indicated the typical character of the platinum fcc structure. The voltammetric profiles of the Pt/Ti for different experimental conditions are similar to that of the typical polycrystalline pure Pt. According with the chemometric results the presence of US, SR, NDC and the interaction between US and SR were significant variables. The best condition evaluated was that performed with higher NDC, in lower SR and in the presence of ultrasound. The results indicate that the ECSA estimated is approximately 2.9 times higher for the Pt obtained with US (in the best condition), when compared to the results obtained without ultrasound. Pt electrodeposits presented promising results for the glycerol electrooxidation process, in which the highest values of current peak were reached in the ultrasound-assisted measurements

     

8
  • CASSIO COSTA LIMA
  • Human health risk assessment in surface soils in the city of Santo Amaro da Purificação, Bahia, Brazil

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • ERIK GALVÃO PARANHOS DA SILVA
  • JORGE MAURICIO DAVID
  • JOSE ANGELO SEBASTIAO ARAUJO DOS ANJOS
  • SERGIO LUIS COSTA FERREIRA
  • Data: 2 avr. 2024


  • Afficher le Résumé
  • Santo Amaro da Purificação is a city in Bahia, approximately 80 kilometers from Salvador. Over the last few decades, it has faced problems of contamination by toxic metals from the waste (scoria) generated by mining activities, which has generated significant environmental liabilities and negatively affected the population. The smelting plant, which operated in this town from 1960 to 1993, was shut down after causing deaths and irreversible adverse effects on the population's health due to contamination by lead and other elements. Twenty-eight surface soil samples were collected in the urban domain of Santo Amaro, Brazil, to assess the risks associated with metal contamination in soil. In this context, lead, cadmium, arsenic, chromium, copper, and zinc, six of the seven elements recommended by Hakanson in 1980 for ecological risk assessment, were determined using inductively coupled plasma-optical emission spectrometry (ICP OES). The following concentration ranges in µg g-1 was found for the analytes As (1,10 to 75,80), Cr (8,48 to 247,00), Cu (8,44 to 245,85), Cd (1,07 to 90,57), Pb (4,65 to 12415,72) and Zn (17,07 to 3511,16). The contamination factor (CF), ecological risk index (Er), pollutant load index (PLI), degree of contamination (mCdeg), and potential ecological risk index (PERI) were used to investigate the level of contamination and ecological risk of the samples. The CF index showed that the samples collected inside the foundry had high contamination by lead, cadmium, and zinc, low contamination by chromium, and low to moderate contamination by arsenic and copper. In addition, the integrated PLI index showed that all the samples collected inside the foundry had high pollution; however, of the other twenty-two samples investigated, only two showed pollution. The ecological risk index showed that soil samples collected from homes near the smelter posed an ecological risk due to cadmium contamination. The PERI showed that samples collected on the city's access road and those collected on streets close to the foundry showed low ecological risk. The results obtained by applying principal component analysis (PCA) and hierarchical cluster analysis (HCA) to the data relating to the levels of chemical elements in the soil samples fully corroborate the results found using the toxicological assessment indices

9
  • IGOR SANDE DE SANTANA
  • Mechanochemistry and telescopic synthesis as synthetic strategies to obtain benzoheterocycles, α-naphthols and new 1,2-naphthoquinone derivatives

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • JULIO CEZAR PASTRE
  • ANDRE ALEXANDRE VIEIRA
  • MAURICIO MORAES VICTOR
  • SABRINA TEIXEIRA MARTINEZ
  • SILVIO DO DESTERRO CUNHA
  • Data: 2 avr. 2024


  • Afficher le Résumé
  • The telescopic approach within organic synthesis has been
    used as an allied tool to achieve synthetic planning
    increasingly sustainable, within the concept and parameters of chemical
    green. This strategy, in addition to offering a reduction in unit stages of
    purification of intermediates, and consequently the generation of waste,
    can also simplify the practical aspects of a synthesis and has already been
    used by the pharmaceutical industry. Furthermore, mechanochemistry also
    has been acting within organic synthesis with an important role in
    more sustainable synthetic planning, in addition to enabling access to
    reactivity and non-trivial reaction conditions employing methods
    conventional. In this work, a synthesis method was developed for the
    obtaining benzoheterocycles (14-72%), 4-acetoxinphthalenes (30-65%) and 4H-
    quinolizin-4-one (88%) from Wittig olefination and acylation reactions
    from Friedel-Crafts, combined in a two-pot telescopic approach,
    employing mechanochemistry and microwave heating respectively.
    The advantage offered by mechanochemistry made it possible to carry out
    olefination in the absence of solvent and in a non-inert atmosphere, bypassing the
    solvent drying steps and purging of the reaction system with
    gases. The developed method uses half-esters as an intermediate
    itaconic (41-87%), which were also isolated and characterized,
    originating from the olefination reaction using α-triphenylphosphoranylidene-
    monomethyl succinate against aldehydes in mechanochemistry. Furthermore, the
    Synthetic potential of itaconic half-esters was explored in the synthesis of 9-
    methyl nitro-2,3-dihydrobenzo[b]oxapin-2-one-4-carboxylate (70%) and 2,3-
    methyl dihydro-1H-benzo[b]azepin-2-one-4-carboxylate (71%), demonstrating
    be a versatile synthetic intermediate by enabling access to molecules with
    structural diversity. From the synthesized 4-acetoxinphthalenes,
    possible to access α-naphthols (81-98%), which, together with other analogues of
    naphthols, were investigated against hypervalent iodine reagents for the
    synthesis of new analogues and derivatives of naphthoquinones using the
    telescopic approach, making it possible to access new benzo[a]phenazines (35-
    85%), pyrido[2,3-a]phenazines (32-93%) and oxazoles (36-56%).

10
  • RODRIGO SANTOS GONZAGA MENEZES
  • Capture of VOCs on activated carbons prepared from the aquatic plant Eichhornia Crassipes: A thermogravimetric study

  • Leader : RAILDO ALVES FIUZA JUNIOR
  • MEMBRES DE LA BANQUE :
  • RAILDO ALVES FIUZA JUNIOR
  • LUCIANA ALMEIDA DA SILVA
  • ARTUR JOSE SANTOS MASCARENHAS
  • RODRIGO DE PAULA
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 5 avr. 2024


  • Afficher le Résumé
  • The high dispersion of volatile organic compounds in the environment raises the need to develop methods to capture these vapors, as they are chemical species with the potential to cause damage to human health and environmental problems, and several essential human activities emit these compounds daily. Adsorption is a technique that deserves to be highlighted in the application for capturing these vapors, as it is a simple procedure, generally does not use expensive materials and, depending on the adsorbent-adsorbate interaction, it is a reversible process that allows the reuse of adsorbents and even a utilization of captured compounds. Activated carbon is an easy material to produce, it has a large surface area making it efficient in adsorption processes. In this work, activated carbons were produced under different pyrolysis and activation conditions, and were subsequently evaluated for the capture of different volatile organic compounds, among which the most adsorbed compound was dichloromethane (301 mg/g). For the evaluation of the adsorptive properties of activated carbons, Thermogravimetry was an excellent ally due to the ease of using the technique for this purpose and acquiring the results, compared to other techniques available in the literature. In the production of activated carbons, biomass derived from an aquatic plant called Eichornnia Crassipes, popularly known as baronesa, was used. This plant was chosen because it has a high reproduction rate and where its proliferation occurs it causes ecological and financial problems, which leads to its mechanical removal and disposal without any destination. Initially, biomass characterizations were carried out to obtain the moisture content, fixed carbon, ash, macrocomponents and quantification of inorganics. At this stage, modern procedures using Thermogravimetry were also applied for comparative purposes with techniques that are commonly used in the literature. Initial characterizations of the biomass showed fixed carbon contents in a range of 28 – 31%, which is one of the most relevant parameters for the production of activated carbon. After the production of coals, it was verified that the surface area of B.E.T. of coals varied in a range from 333 to 950 m2 /g and micropore area between 421 and 1200 m2 /g. With activated carbon with the largest surface area, the adsorption capabilities of volatile organic compound vapors were evaluated, using thermogravimetry, as well as the thermodynamic and kinetic properties of the adsorption processes. A decrease in adsorption capacity was observed with increasing temperature, characteristic of a physisorption process. The adsorption curves were correlated with pseudo-first-order, pseudo-second-order adsorption mathematical models and the Avrami model. These correlations showed higher coefficients with the pseudo-first order model (r2 = 0.9562 – 0.9915), which also indicate that physical adsorption is the dominant process, but the significant values of the correlations with the Avrami model ( r2 = 0.9899 – 0.9955) indicate a contribution from chemical adsorption between the vapors of the studied compounds and the activated carbon.

Thèses
1
  • UILLIAN MOZART FERREIRA DA MATA CERQUEIRA
  • Doehlert design in the development of alternative analytical methods for determining metals in spirulina (Arthrospira sp.) commercial samples.

     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • CLEBER GALVAO NOVAES
  • LIZ OLIVEIRA DOS SANTOS
  • LUCIANA ALMEIDA DA SILVA
  • SERGIO LUIS COSTA FERREIRA
  • VALFREDO AZEVEDO LEMOS
  • WALTER NEI LOPES DOS SANTOS
  • Data: 22 févr. 2024


  • Afficher le Résumé
  • Procedures for optimizing analytical methods using multivariate techniques have been increasingly applied as they are more economical and effective. The Doehlert design matrix has gained prominence for being versatile and efficient, in addition to offering greater flexibility in choosing the levels of the variables under study. Additionally, there is a growing demand for sample preparation procedures that are environmentally friendly, enable the availability of analytes with simpler, faster, safer strategies and that provide results as reliable as those obtained by the established methods. In this work, Doehlert matrix was applied in the development of three analytical sample preparation methods aiming to determining metals in spirulina (Arthrospira sp.) – cyanobacterium used as a food supplement in humans and animals and considered by many nutrition science researchers as a functional food. Two alternative methods to sample mineralization were developed: (i) cyanophyte slurry sampling for the determination of Fe, Mn and Zn by FAAS; (ii) alkaline extraction with tetramethylammonium hydroxide (TMAH) in order to determining Ca, Fe, Mg, Mn and Zn by FAAS. A third method was developed applying cloud point extraction for the separation and pre-concentration of copper and determination by Digital Image Colorimetry. The developed methods were validated by obtaining its characteristics of analytical merit and were applied to spirulina samples – powder and capsules – commercialized in the cities of Salvador and Jequié-Ba.

     
2
  • VIVIANE PAPA DA SILVA
  • SYNTHESIS AND CHARACTERIZATION OF METALLOPHTALOCYANINE COORDINATION COMPOUNDS OCCLUDED IN ZEOLITE Y FOR NOx SENSING

  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • VALERIA CRISTINA FERNANDES
  • LUCIANA ALMEIDA DA SILVA
  • LUIZA AMIM MERCANTE
  • MAURICIO BRANDAO DOS SANTOS
  • RODRIGO DE PAULA
  • ELIANA MIDORI SUSSUCHI
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 1 mars 2024


  • Afficher le Résumé
  • There is a growing search for selective and sensitive materials that can be used as gas sensing agents. These materials need to present certain characteristics, such as reusability and high resistance, in order to be effectively used. Among the species most used for this purpose are coordination compounds. These molecules are widely used because they present properties that can be monitored when chemically interacting with various gases, such as luminescence and variation in the oxidation state. Within this context, metalphthalocyanines gain prominence, as they are materials that present high stability and unique electrochemical properties, being able to interact in a coplanar way with several molecules. The synthesis of these compounds occluded in zeolites constitutes a system that has been studied over the last 30 years, with the aim of promoting shape selectivity to the materials obtained. This synthesis occurs by inserting fragments of the compound into zeolites previously exchanged with the ions of interest, a method called ship-in-the-bottle. Once obtained, these materials present a series of advantages due to greater conservation of the active site and the reduction of the coplanar interaction phenomenon, which results in phthalocynanine aggregates. Despite being a known synthesis, the ship-in-the-bottle process of phthalocyanines in zeolites constitutes a challenge, especially with regard to the characterization and location of these compounds in nanoporous materials. However, once obtained, these materials can be used in a wide variety of applications. The use of NOx gases as sensors is of great interest, as these are gases emitted into the atmosphere from various anthropogenic sources. In this work, the synthesis and characterization of phthalocyanines of copper(ll), cobalt(ll), nickel(ll) and iron(ll), pure and occluded in Y zeolites, were carried out. These materials were characterized using X-ray diffraction techniques. , energy-dispersive X-ray spectrometry, infrared spectroscopy, UV-Vis absorption spectrometry, cyclic voltammetry, thermogravimetry and textural characterization by N2 physisorption. The electrochemical potential of these materials was studied by cyclic voltammetry using chemically modified electrodes. The electrochemical analyses carried out showed good performance of materials containing cobalt phthalocyanine occluded in zeolite Y for detecting NO gas.

3
  • TAMILLE ALVES SOUZA
  • Fe, Cu and Alumina Catalysts for occurrence of reverse shift (RWGS) and activation of Carbon Dioxide

     
     
  • Leader : HELOYSA MARTINS CARVALHO ANDRADE
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • FERNANDA TEIXEIRA CRUZ
  • HELOYSA MARTINS CARVALHO ANDRADE
  • KAREN VALVERDE PONTES VATER
  • RAILDO ALVES FIUZA JUNIOR
  • RENAN TAVARES FIGUEIREDO
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • VALERIA CRISTINA FERNANDES
  • Data: 4 mars 2024


  • Afficher le Résumé
  • Carbon dioxide(CO2) emission for atmosphere in the last years became a largest numbers, and consequently, has been causing severe climate change and ocean acidification. Therefore, the objective of this work was the preparation and evaluation of the catalyst Fe, Cu, Ce and Al base for reverse water gas shift reaction (RWGS), with the aim of CO2 activation to CO. The carbon monoxide (CO) is more reactive than CO2, so the CO production can be used as an intermediate step to facilitate a CO2 conversion in others products of industrial interest, as methanol, dimethyl ether (DME) from syn gas. First of all, the catalyst had been prepared for two methods (coprecipitation about the support and impregnation), in diferentes compositions off Copper in supported in Al2O3 or CeO2-Al2O3, in sequence, they were characterized ((FRX, TG/DTA, DRX, FTIR, MEV, TPR e Análise textural (BET e BJH)), tested in RWGS reaction, also a mechanism study was carried out with drifts in situ and a CAMERE simplificated study. The catalysts were active, selective and stable in the RWGS reaction, with CO2 conversions of up to 65%, CO selectivity of up to 100% and CO yield of approximately 60%, over reactions lasting 8 and 16 hours. The increase of quantity of copper in the catalysts favored the increase in CO selectivity. The incorporation of ceria in the catalysts did not result in a significant increase in activity, but contributed to the stability of the magnetite phase and less coke formation. Differences between catalyst preparation methods favored the formation of catalysts with different properties, however, they did not significantly influence the activity of the catalysts. So, the two preparation methods used in this work were efficient and are alternatives for the preparation of active catalysts in the RWGS reaction. From the in situ drifts tests of the RWGS reaction, it is concluded that the mechanism via format intermediates is the priority route in all catalysts studied, and that incorporation of CeO2 into catalysts interferes with the types of intermediate species that are formed in the reaction, in addition to became the RWGS reaction more selective. It was confirmed that iron oxide is the main active site for the RWGS reaction, however, the formation of CH4(g) only occurs in these sites, therefore, the insertion of Cu in the composition of the catalysts is essential to ensure selectivity from the catalyst to CO. Through the study of CO hydrogenation by in situ drifts, it was concluded that the catalysts studied in this work have the potential to produce methanol, olefins or ether. The CAMERE system doubled the methanol yield compared to direct CO2 hydrogenation. This approach shows that the RWGS reaction before the methanol synthesis is a promising route for increasing methanol yield, even at atmospheric pressure.

     
     
4
  • LEONARDO BRITO GUIMARÃES
  • DEVELOPMENT OF A ANALYTICAL METHOD BASED ON EXTRACTION INDUCED BY EMULSION BREAKING FOR MULTIELEMENTAL DETERMINATION IN LUBRICANT OIL BY OPTICAL EMISSION SPECTROMETRY WITH MICROWAVE INDUCED PLASMA (MIP OES)

  • Leader : FABIO DE SOUZA DIAS
  • MEMBRES DE LA BANQUE :
  • MARIANELA SAVIO
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • ERIK GALVÃO PARANHOS DA SILVA
  • FABIO DE SOUZA DIAS
  • LEONARDO SENA GOMES TEIXEIRA
  • LICIA PASSOS DOS SANTOS CRUZ
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • Data: 28 mars 2024


  • Afficher le Résumé
  • The determination of trace chemical elements in lubricating oil contained in engine compartments is a relevant area of tribology and, it is an indication of wear, oxidation of mechanical components and the quality of additives used for better engine performance. The complexity of the lubricating oil matrix is the subject of study for the search for less aggressive and interference-free strategies for sample preparation, such as extraction induced by emulsion breaking (EIEB) which has stood out in the last decade for oils and fats. This work aimed to develop an analytical procedure from extraction induced by emulsion breaking (EIEB) for multielement determination in lubricating oil samples by microwave-induced plasma optical emission spectrometry (MIP OES), foregoing high-cost mechanical devices. The time required for cleavage and extraction of the analytes was evaluated, achieving global sensitivity in 40 minutes. The Doehlert Matrix response surface methodology was used to study the effects and interactions between the concentration of nitric acid and surfactant in EIEB, obtaining the optimum conditions for 3.0 g of sample: 2.80 mol L-1 of nitric acid and 3.0 % (m/v) of the surfactant Triton X-114. The plasma condition and interferences of the extract introduced into the N2 plasma were evaluated by monitoring molecular species (CN, CH and C2), atomic and ionic emission lines of the analytes to select the most sensitive and interference-free one and the flow rate of the nebulizer gas (0.3 – 0.8 L min-1) for each analyte in the matrix. The limits of quantification of the developed method obtained for Al, Cr, Cu, Fe, Mg, Mn, Mo, Ni and Pb were 2.9, 43, 4.0, 17, 4.0, 3.7, 7.0, 9.2 and 45 µg kg-1, respectively. The accuracy of the method was assessed using the addition and recovery test for three different samples and by comparing the EIEB with another established method, with the percentage of recovery and agreement varying between 84 and 120%. The method developed based on EIEB showed multielement capacity with precision and accuracy, and was therefore explored in other lubricating oil samples for the determination of trace elements with the following concentration ranges (mg kg-1): 2.49 – 106, 1.78 – 24.8, 0.25 – 21.6, 16.4 – 378, 7.78 – 76.5, 0.33 – 9.65, 4.65 – 43.2, 1.58 – 11.1 and 4.6 – 12.6 for Al, Cr, Cu, Fe, Mg, Mn, Mo, Ni and Pb respectively. The principal component analysis and the self-organization map of Kohonen were effective for exploratory analysis to correlate the concentrations of trace elements with the samples of lubricating,

5
  • FERNANDO ALVES BARRETTO
  •  

     
     
     
     
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    Resultados de tradução

    Resultado da tradução

    SYNTHESIS OF FUNCTIONALIZED COUMARINS VIA NOVOFORMAL [4+2] OXA-CYCLOADDITION PATTERN OFMALEIMIDES WITH 2-HYDROXYALDEHYDES
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • FERNANDA GADINI FINELLI
  • ANDRE ALEXANDRE VIEIRA
  • FERNANDA ANDREIA ROSA
  • JORGE MAURICIO DAVID
  • KLEBER THIAGO OLIVEIRA
  • SILVIO DO DESTERRO CUNHA
  • VALERIA BELLI RIATTO
  • Data: 3 avr. 2024


  • Afficher le Résumé
  • In this work, we conducted an unprecedented study of the synthetic applications
    of substituted coumarins via the formal oxa-[4+2] cycloaddition reaction of 2-
    hydroxy-aldehydes and maleimides. Forty-six new coumarin and itaconimide
    were obtained, with 7% to 68% yields. In the applications of formal cycloaddition
    reactions using maleimides, a new pattern of ambiphilic (C,O) reactivity was
    discovered, given that the applications of maleimides in Diels-Alder and
    binucleophilic (N,N), (N,C), (N,S), (N,O) cycloaddition reactions are already
    known. An unprecedented methodological transposition was developed, using
    continuous flow, and coumarins were obtained with yields between 40% and
    63%. The photophysical study showed that the angular coumarins exhibited
    fluorescence when excited at a wavelength of 200 nm. Only four coumarins
    (118z), (118af), (118ac), and (118ag) showed emission at wavelengths in the
    405-436 nm range, while the others exhibited no emission at this excitation.
    Coumarin (118ag) displayed a bathochromic shift in the visible region, while
    coumarins (118z), (118af), and (118ac) showed an ipsochromic shift in the visible
    region. The presence of withdrawing substituents on the maleimide ring led to
    emission in the 405-436 nm region, whereas with donor groups, we observed no
    emission

6
  • THAIS LUZ DE SOUZA
  • TOTAL AND BIOACCESSIBLE CONTENT OF PHENOLIC BIOACTIVES AND INORGANIC CONSTITUENTS IN NUTRITIOUS FLOUR SAMPLES

  • Leader : DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • DÉBORA DE ANDRADE SANTANA
  • GISELE ANDRE BAPTISTA CANUTO
  • LAÍS ARAÚJO SOUZA
  • MADSON DE GODOI PEREIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • Data: 19 avr. 2024


  • Afficher le Résumé
  • Phenolic bioactives, present in plant foods, modulate reactive species in the human body and inorganic constituents such as Cu, Fe, Mn, Zn, Ca, K, P participate in vital functions in the body. The aim of this study was to determine the total and bioaccessible contents of phenolic bioactives and inorganic constituents in nutritious flour samples. The bioactive extraction procedure (gallic, protocatechuic, chlorogenic, caffeic, syringic, p-coumaric, sinapic, ellagic acids and the flavonoids catechin, rutin, quercetin and kaempferol) consisted of: 0.25 g sample + 1.5 mL of acetone + 8.5 mL of methanol, in ultrasound at room temperature for 30 min and determination by high-performance liquid chromatography with diode array detector (HPLC-DAD). For inorganic constituents (Al, Ba, Ca, Cu, Fe, K, Na, Mn, Mg, P, Sr and Zn), were used 0.25 g of sample + 7.0 mL of HNO3 5.0 mol L -1 + 1.0 mL of 30% H2O2 (m m-1), at 200 °C for 45 min, in a digester block with a closed system and determination by inductively coupled plasma optical emission spectrometry (ICP OES). The LOQ of bioactives, in µg g-1, ranged from 2.76 (ellagic) to 3.90 (catechin) and of inorganic constituents from 0.005 (Na) to 13.94 (Al). To extract the bioaccessible fraction of phenolics and inorganic constituents, the INFOGEST in vitro static simulation was used. The bioactive contents, in µg g-1, varied between: < 0.17 to 1.37 ± 0.07 (ellagic) and < 0.16 to 88.83 ± 0.72 (catechin). Kaempferol was below the LOQ. For inorganic constituents, in µg g-1, they varied between: 0.09 ± 0.01 to 6.67 ± 0.77 (Al) and 0.59 ± 0.07 to 32.96 ± 3.28 (Fe). The elements Al, Cu, Fe and Zn were below the LOQ in some flour samples. The bioaccessible fraction ranged from 0.87 to 98.0% in phenolic bioactives and 0.21 to 73.3% in inorganic constituents.

2023
Thèses
1
  • Jennifer Blandón Pardo
  • Biflavonoids and other constituents from the fruits of Schinus terebinthifolius (Anacardiaceae)

     
     
  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • ELIANE DE OLIVEIRA SILVA
  • CLAYTON QUEIROZ ALVES
  • Data: 14 févr. 2023


  • Afficher le Résumé
  • The  Anacardiaceae family has a worldwide geographical distribution and the genus Schinus L stands out for the amount of species associated with it and properties in traditional medicine. The species Schinus terebinthifolius, widely known in Brazil for its use as seasoning, ornamentation and traditional medicine. In order to re-study the chemical composition of S. terebinthifolius fruits, to evaluate the bioactivity against pathogenic agents (E. coli, S. aureus and P. aeruginosa) and inhibition of acetyl enzymes (AChE) and butycholinesterase (BChE) of extracts, organic soluble fractions and pure substances; the hexane and methanolic extract were prepared by the macerated method, the latter submitted to partition with chloroform and ethyl acetate. After separation and purification of the constituents, the uni (NMR 1H, NMR 13C) and bi-dimensional (HSQC, HMBC) experiments were used for the identification, as well as liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). From these proceedings two tirucalaan triterpenoides were identified: acid (Z)-masticadienoic acid (ST1), masticadienolic acid (ST2); tetrahydrobiflavone (ST3) and a derivative of the gallic acid: 4-O-methylgallic acid (ST4). In the tests against pathogens, between extracts and organic phases, the best growth inhibition was found for the chloroform phase against the three microorganisms evaluated with MIC between 50-75 μg.mL-1 and the pure substances resulted in more promissory ST3 and ST4 with MIC between 25-75 μg.mL-1 against the three microorganisms. Regarding the inhibitory activity of the enzymes AChE and BChE, both for extracts and for organic phases and pure substances, a percentage of moderate inhibition was identified. Therefore, the bioactive potential of the species under study was highlighted, mainly from the chloroform phase for the search for substances of pharmacological interest.

     
     
2
  • Luis Henrique de Queiroz Guimarães
  • DETERMINATION OF OXITETRACYCLINE IN GROUNDWATER VIA RESONANT ENERGY TRANSFER (RET) PHENOMENON USING QUANTUM DOTS

     
  • Leader : RODOLFO DE MELO MAGALHAES SANTANA
  • MEMBRES DE LA BANQUE :
  • RODOLFO DE MELO MAGALHAES SANTANA
  • LEONARDO SENA GOMES TEIXEIRA
  • MADSON DE GODOI PEREIRA
  • Data: 15 juin 2023


  • Afficher le Résumé
  • Antibiotics, such as oxytetracycline, are a group of emerging contaminants used in human and veterinary medicine and used as an additive in animal husbandry. Thus, its residues can be found in the most diverse matrices, such as food of animal origin and environmental samples, at trace and ultra-trace levels, requiring increasingly sensitive analytical methods. In this context, quantum dots (QD) stand out, acting as energy donors by resonance (Resonance Energy Transfer - RET) to other luminescent species, allowing the development of analytical methods with low limits of detection and quantification. The present work aims to evaluate the occurrence of RET between QD of CdTe coated with mercaptopropionic acid (MPA) and oxytetracycline (OTC) and its application in the determination of this antibiotic in groundwater samples. The RET investigation was performed by determining the donor/acceptor spectral overlap, quantum yield (ΦCdTe-MPA), and Föster critical radius R0. The developed method was optimized for medium pH and buffer composition. A significant increase in OTC emission (ΔF ≥90%) was observed in the presence of 3.2 nm nanocrystals, with displacement between the emission bands (~130 nm) of QD and analyte. Overlap of normalized OTC absorption and QD emission spectra (J(λ) = 1.012 x 1011 L nm4 mol-1 cm-1) was observed with high proximity between donor and acceptor (R0 = 0.0987 nm). Although the quantum yield of the donor (ΦCdTe-MPA = 49%) is within that reported in the literature, values of R0 < 1 nm indicate the non-occurrence of the phenomenon of FRET (Föster Resonance Energy Transfer) – long-range interactions, but a probable electronic transfer by the Dexter mechanism (short-range interaction). Finally, the method under optimal conditions presented LOD and LOQ of 0.086 and 0.262 μmol L-1, respectively, with an upper limit of the linear working range equal to 30.0 μmol L-1 (R = 0.99924, n = 8), with good sensitivity (13.321 intensity L μmol-1) and precision (RSD ≤ 1.2%; n=6, COTC =15 μmol L-1). The method showed good selectivity with a variation of less than 5% of the analytical signal for inorganic species commonly found in groundwater samples and TC, a molecule analogous to the analyte. Recovery percentages between 89 and 99% were obtained, indicating the accuracy of the proposed method. Thus, this method presents itself as a simple alternative for quantifying oxytetracycline at trace levels based on electronic energy transfer in water samples.

     
3
  • Luiza Maria Cerqueira Silva
  • Pseudocapacitor materials for application in charge storage devices

     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • VALERIA CRISTINA FERNANDES
  • RAILDO ALVES FIUZA JUNIOR
  • ARTUR JOSE SANTOS MASCARENHAS
  • IURI MUNIZ PEPE
  • ERNESTO CHAVES PEREIRA DE SOUZA
  • Data: 28 juin 2023


  • Afficher le Résumé
  • The development of new materials applicable to energy storage and conversion has been of great relevance in the last four decades. There is significant emphasis on research with transition metal oxides due to the chemical, electronic, optical, and magnetic properties inherent in this class of materials. Manganese oxide (MnO2), because it's a low-cost oxide, easy to obtain, and has several synthesis methods, presents itself as a promising oxide for application in energy storage devices, especially in batteries and electrochemical capacitors. From a practical standpoint, the electrochemical properties of MnO2 can be improved as the variables of oxide preparation are studied. This work proposes to verify how it is possible to improve these properties, investigating the use of metallic titanium (Ti), stainless steel (SS), platinized titanium (Ti/Pt), and platinum (Pt) substrates, as well as the use of Na2SO4 1 mol L-1 as supporting electrolyte in the MnSO4 0.4 mol L-1 solution used in the electrodeposition process. Furthermore, the mechanism of charge storage and electronic transfer of the oxide through mechanical oscillation frequencies during the electrochemical synthesis of materials was investigated using the Electrochemical Quartz Crystal Microbalance (EQCM) technique as a function of different temperature conditions. In these processes, an initial potential of the peak oxidation was observed, in the anodic scan, varied according to the substrate used. There was a shift towards more positive potentials as Ti, SS, Ti/Pt, and Pt substrates were used, respectively. However, using the MnSO4 solution in Na2SO4, the oxidation process started at less positive potentials, which favors the system in terms of energy. Furthermore, regardless of the electrolyte used, the electrodeposition curve was preserved in the voltammetric profile. The electrochemical characterization of the deposited MnO2 thin films shows a significant difference in the current densities of the anodic and cathodic processes. Furthermore, the anodic peak associated with the MnIV-MnVI transition appeared well-defined and at the less anodic potential for the MnO2 films deposited on the SS, Ti/Pt, and Pt electrodes. Analyzed the electrochemical characterizations, a significant increase in current density is observed in comparison with the solution without this electrolyte. The electrodeposits on Ti substrates showed a more rectangular voltammetric profile, which is characteristic of pseudocapacitive materials, however, Ti/Pt/MnO2 electrodes showed the highest values of specific capacitance. The presence of Na2SO4 in the deposition solution resulted effectively in an increase in the storage capacity of the deposited oxide. With the MnSO4+Na2SO4+H2O solution, the specific capacitance was 450 F g-1, against 216 F g-1 (for the film deposited on MnSO4+H2O), at a speed of 2 mV s-1. In morphological terms, all electrodes showed cracks, which is a characteristic morphology of MnO2 oxides, however, the islands were smaller in the materials synthesized in the presence of the Na2SO4 electrolyte, thus resulting in a greater number of cracks and this condition directly reflects on the increase of the pseudocapacitive properties of the electrode.

     
4
  • Najara Santana Pita
  • Study of the action of TiO2-based photocatalysts supported on sewage sludge for the removal of pollutants from river water

     
     
     
     
     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • ARTUR JOSE SANTOS MASCARENHAS
  • MARIANA DE SOUZA SIKORA
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 4 juil. 2023


  • Afficher le Résumé
  • Environmental pollution is a great worry in the whole world, among the affected environments, the rivers stand out as impacted by anthropogenic activities – in urbanized areas, they have a large pollution load. Another critical issue that stands out is the need for safe disposal of domestic sewage sludge – a byproduct created by the Wastewater Treatment Plant (WWTP). In this work, TiO2 nanoparticles were developed being used as support for sewage sludge. These nanoparticles have already been widely studied in the last decades in advanced oxidative processes for environmental decontamination, being supported in treated sewage sludge. Heterogeneous photocatalysis based on semiconductors, such as TiO2, occurs by photoactivation of the semiconductor particles with UV radiation, generating species highly oxidizing. Since the photoactivity of the material is highly dependent on its morphological and microstructural properties, alterations were also held in this material for the addition of transition metal, using Pt4+ e W6+ ions, by Pechini Method. Semiconductors were characterized by X-ray diffraction (XRD) and diffuse reflectance (DRIFT). These studies allowed us to relate the photoactivity of the synthesizes materials with their optical characteristics. These materials photocatalytic activity was screened in front of a model compound (methylene blue) and, subsequently, they were used in the study of the removal of pollutants in river water real samples. In these trials were investigated the parameters COD, phosphorus, nitrogen, and coliforms. The results obtained of the discoloration of the solution of the model compound using the TiO2 composites were considerably good – reaching, in some composites values higher than 80%. The composites also showed promise in the removal of some pollutants present in actual samples.

     
     
     
     
     
5
  • Catherine Pinheiro de Almeida
  • Uniting physiology, biochemistry and metabolomics to unravel responses to abiotic stresses in Glycine max and Ricinus communis

  • Leader : PAULO ROBERTO RIBEIRO DE JESUS
  • MEMBRES DE LA BANQUE :
  • PAULO ROBERTO RIBEIRO DE JESUS
  • WALTER NEI LOPES DOS SANTOS
  • CALINE GOMES FERRAZ
  • ELISANGELA FABIANA BOFFO
  • LUZIMAR GONZAGA FERNANDEZ
  • RENATO DELMONDEZ DE CASTRO
  • FRANCISCO JOSE LIMA ARAGAO
  • TIAGO VENÂNCIO
  • Data: 1 août 2023


  • Afficher le Résumé
  • Every year, plants suffer various damages caused by climatic conditions, such as drought and high temperatures, which considerably reduce crop yields worldwide. In arid and semi-arid regions, some cultivars are exposed to these two adverse conditions, causing a series of damages, mainly in seed germination, of extreme importance in the life cycle of plants. Glycine max L. Merrill (soybean) is one of the most important crops in the world due to its application in the fuel, chemical, food and agroindustry industries. Soybean plants are highly sensitive to thermal stress, especially in the reproductive phase. Ricinus communis is a plant native to Africa and Asia, belonging to the Euphorbiaceae family. It is a very productive and resistant culture, being easily cultivated in drier and hotter regions. Unlike cultures like soybeans that are sensitive to high temperatures, Ricinus communis manages to present good production results even under thermal stress. The main objective of this study is to characterize the GDSL esterase/lipase gene from Ricinus communis (RcGELP) and to evaluate the effect of its overexpression and silencing in Arabidopsis thaliana against abiotic stresses, and to evaluate the metabolome of soybean seeds against stress thermal. To achieve this objective, the germination of A. thaliana seeds that overexpress and silence the RcGELP gene against water and heat stress will be evaluated, as well as to identify and quantify primary metabolites in the seeds. Seed germination and establishment of soybean seedlings will also be evaluated at high temperature, followed by metabolomics analysis. As one of the main results, it is expected to relate the metabolomic analyzes with the behavior of seeds during germination under abiotic stress and the function that the GDSL esterase/lipase gene confers on A. thaliana seeds. Studies like this one can contribute to the understanding of the molecular and biochemical aspects of the mechanisms related to germination and establishment of seedlings in the face of abiotic stresses.

6
  • Mirtes Fernanda Sobrinho de Freitas
  • CONVERSION OF FURFURAL USING DOUBLE CATALYTIC BED OF CUY E NIY TO OBTAIN SUSTAINABLE CHEMICALS

     
     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • RAILDO ALVES FIUZA JUNIOR
  • HELOYSA MARTINS CARVALHO ANDRADE
  • ARTUR JOSE SANTOS MASCARENHAS
  • CESARIO FRANCISCO DAS VIRGENS
  • Data: 7 août 2023


  • Afficher le Résumé
  • The quest for a sustainable society has generated significant interest in research and development on the conversion of biomass into chemical products with high added value. Furfural is a reagent that can be obtained from inedible lignocellulosic biomass and its derivatives are products of interest in the biorefinery. This study was developed with the objective of investigating the conversion of furfural (FF) through the hydrodeoxygenation reaction using a double catalytic bed of CuY and NiY. The products of interest were: furfuryl alcohol, 2-methylfuran, 2-methyltetrahydrofuran and tetrahydrofurfuryl alcohol. The monometallic catalysts supported on HY zeolite were prepared by the impregnation method with 10, 20 and 30% copper and 10% nickel and were characterized by XRD, TG/DTA, SEM, ASAP, FITR, DRS-UV-Vis and TPR- H2. The catalysts were evaluated in the range of 180 to 260°C, using a fixed bed benchtop reactor, packed with a single catalyst bed or a double bed, composed of CuY and NiY catalysts, forming double beds with different configurations. The pattern of preferential activity of the CuY catalyst for activation of the C=O group of furfural was observed, while on NiY, reaction products in the C=C and C=O groups were observed. Furfural conversions close to 100% were observed over CuY and 37% over the NiY catalyst, in a single beds. High yields of up to 87% of furfuryl alcohol were obtained with the CuY catalyst at 180°C, while the use of the 20CuYQZ10NiY double bed made it possible to obtain 2-methylfuran with a yield above 80%, at 220°C, with high stability for 10 hours. Regardless of the reactor packing order, after the reaction, the double beds showed a smaller volume of coke deposits than the CuY catalyst, suggesting greater stability in relation to coking when the double bed is used.

     
     
7
  • Rhaissa Ribeiro Barbosa
  • Physiological and metabolomics evaluation of Ricinus communis seed germination and phylogenetic and functional analysis of overexpressed GDSL esterase/lipase genes in Arabidopsis thaliana

     
  • Leader : PAULO ROBERTO RIBEIRO DE JESUS
  • MEMBRES DE LA BANQUE :
  • PAULO ROBERTO RIBEIRO DE JESUS
  • CALINE GOMES FERRAZ
  • LIV SOARES SEVERINO
  • ANTONIO GILBERTO FERREIRA
  • Data: 9 août 2023


  • Afficher le Résumé
  • Ricinus communis is an important oilseed crop with great socioeconomic impact, and is also essential for small family farmers in semi-arid regions of Brazil and the world. Its resistance to adverse conditions, such as thermal and saline stress and water restriction, is very interesting; as well as the metabolic pathways and genes involved in this resistance to these stresses. Despite this, few studies have been carried out on the metabolic and genetic profile, as well as the possible contribution that these data can provide for the survival of crops in different environmental conditions. R. communis seeds were germinated under thermal stress conditions (35°C) and at the ideal growth temperature (25°C), in periods of five and fifteen days, where several physiological parameters were observed. This action was developed with the aim of better understanding the metabolic profile of R. communis seedlings, through Nuclear Magnetic Resonance (NMR) analysis and multivariate statistical analysis, in addition to proposing which metabolic pathways may be being used by them to resist stress. thermal. Among the genes expressed by R. communis, some stand out for being activated in the face of abiotic stresses. The present work is dedicated to studying the GDSL esterase/lipase gene family; the proteins encoded by this family play an important role in lipid metabolism. Due to their substrate specificity, these enzymes are considered highly promising with potential use for applications in several areas. The GDSL esterase/lipases already studied demonstrate as main physiological functions the role in the regulation of development and growth, morphogenesis and lipid metabolism of plants. Species overexpressing GDSL esterase/lipase genes showed greater resistance to several abiotic and oxidative stresses. Despite the socioeconomic importance of R. communis in semi-arid regions, the characterization of the GDSL esterase/lipase genes and their possible contribution to the survival of R. communis plants was not found in the literature. Thus, this work also aimed to characterize the Ricinus communis GDSL esterase/lipase family (RcGELP), through bioinformatics data, such as gene structure, subcellular location, phylogeny, among others. Furthermore, we analyzed the germination against saline stress and water restriction of Arabidopsis thaliana seeds overexpressing or silencing RcGELP genes in comparison with a wild lineage; in order to understand the role of these genes in plant resistance to abiotic stresses. We also developed a metabolomic analysis of samples of germinated seedlings against the aforementioned stresses in order to understand which metabolites and metabolic pathways are involved in the resistance of these seeds and their relationship with overexpression and/or silencing of RcGELP genes. These results can contribute to genetic improvement programs aimed at the development of plants with high tolerance to abiotic stresses. Providing economic and social support to farmers in semi-arid areas around the world.

     
8
  • Carolina Ravazzano Azevedo Lopes
  • FORMATION AND STABILITY OF LIQUID-GAS FOAMS FROM AQUEOUS SOLUTIONS CONTAINING CARDANOL-BASED SURFACTANTS

  • Leader : GUILHERME AUGUSTO FERREIRA
  • MEMBRES DE LA BANQUE :
  • AURORA PÉREZ GRAMATGES
  • GUILHERME AUGUSTO FERREIRA
  • HENRIQUE RODRIGUES MARCELINO
  • MATEUS FERNANDES VENANCIO
  • TIAGO VINICIUS ALVES
  • Data: 10 août 2023


  • Afficher le Résumé
  • Aqueous foams are liquid-gas dispersions that fall within the colloidal scale and sport multiple applications both in the field of industry and in household products. However, being dispersions, these constitute non-equilibrium systems, making the use of agents capable of promoting their formation and ensuring their kinetic stability a necessity. Surfactants constitute the most common class of such agents. These substances display affinity for both phases (liquid and gas) and contribute to reduce the energy investment needed as of their mixing. Most conventional surfactants are synthesized from petroleum derivatives and count with other undesirable properties from an environmental perspective – such as a toxic effect on marine organisms – and these have prompted the study and development of environmentally friendlier alternatives. In this sense, the present work investigated the formation and stability of foams prepared from aqueous solutions of three non-ionic surfactants derived from cardanol, a compound extracted from the liquid of cashew nutshells that has garnered attention as a sustainable precursor for molecules of interest in a wide variety of industrial fields. The surfactants, which were studied individually and as part of binary mixtures prepared with sodium dodecyl sulfate (SDS), differ between one another only in the number of ethoxy groups (EO) that make up the hydrophilic moieties of their molecules (nEO, n = 7, 9 or 12). Foamability tests were conducted with foams prepared by mechanical agitation of a fixed volume of solution. Foam stability, in its turn, was comparatively assessed for dispersions produced using the Tessari technique. The obtained results were corroborated by studies on the thermoresponsive behavior of the cardanol-derived surfactants, by static and dynamic tensiometry measurements and by dynamic light scattering, turbidity and bulk rheology analyses. No significant synergistic effect was observed for the nEO-SDS mixtures at all tested concentrations; in particular, the stability of foams prepared from these binary solutions proved equal to that attained with SDS solutions of same concentration. For the individual systems, the solutions prepared with the cardanol-derived surfactant with 9 ethoxy units in its hydrophilic moiety (9EO) at 1.0% and 2.0% v/v produced the most kinetically stable foams. The greater stabilization capability of these systems was attributed to the morphology adopted by 9EO aggregates at the temperature at which the experiments were conducted: the aforementioned aggregates constituted elongated, rod-like micelles that entangle with each other, increasing bulk phase viscosity and hindering liquid drainage. The gathered results prove themselves relevant due to the fact that they (1) demonstrate the potential of new, sustainable compounds as ingredients for high-quality foaming formulations as well as (2) evidence the existence of a delicate – and, more often than not, neglected in the specialized literature – balance between the surface properties of a system and the characteristics of its continuous phases.

9
  • WILLIAM QUARESMA FERREIRA
  • Determination of essential and potentially toxic elements in different tissues of fish species
    from the Amazon region

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • ANDERSON SANTOS SOUZA
  • GISELE MARA HADLICH
  • JOAO BATISTA PEREIRA JUNIOR
  • LICIA PASSOS DOS SANTOS CRUZ
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • SERGIO LUIS COSTA FERREIRA
  • Data: 1 sept. 2023


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  • Fish represent one of the primary sources of intake of vitamins, proteins, and minerals, contributing to a balanced and beneficial diet for humans. However, to assess the contamination risks of the environment in which they live, it is necessary to determine the concentration of essential and potentially toxic elements that can pose severe risks to human health. Therefore, this study aims to determine essential and potentially toxic elements (Al, As, Ca, Cr, Cu, Fe, K, Mn, Na, P, S, and Zn) in eight tissues (bladder, gills, stomach, liver, gonad, intestine, muscle, and kidney) of seven species of fish from the Amazon region, such as Plagioscion squamosissimus, Hypophthalmus edentatus, Brycon amazonicus, Prochilodus nigricans, Colossoma macropomum, Mugil liza, and Brachyplatystoma rousseauxii. The determination of analytes in fish tissues was evaluated by inductively coupled plasma optical emission spectrometry (ICP OES) after microwave-assisted digestion of the samples. The method's accuracy was assessed by analyzing two certified reference materials: fish protein (DORM-4) and oyster tissue (NIST 1566b). The concentration ranges of the elements determined in the samples were (in mg kg-1): Al (1.35-6568); As (0.67-5.76); Ca (11.25-24303); Cr (0.36-3.94); Cu (0.13-54.65); Fe (2.42-5085); K (433-4905); Mn (0.05-399); Na (68-2674); P (313-13874); S (436-3787), and Zn (0.59-46.34). Multivariate analysis techniques (PCA and HCA) were used to assess whether or not there were trends and/or agglomeration between different fish species and tissues according to the levels of the analytes studied.

10
  • Victor Silva Alves de Lira
  • METABOLOLITE PROFILING, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF EXTRACTS OF Blanchetia heterotricha DC and Zanthoxylum nemorale Lam

     
     
  • Leader : PAULO ROBERTO RIBEIRO DE JESUS
  • MEMBRES DE LA BANQUE :
  • PAULO ROBERTO RIBEIRO DE JESUS
  • CALINE GOMES FERRAZ
  • FLORICEA MAGALHAES ARAUJO
  • LOURDES CARDOSO DE SOUZA NETA
  • Data: 1 sept. 2023


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  • Zanthoxylum nemorale and Blanchetia heterotricha are species widely
    used in the quilombola community of Três Lagoas, located in Amargosa,
    Bahia, due to its medicinal properties. However, there are few
    scientific records reporting the chemical composition and biological activity of these
    species. In this context, this study aimed to characterize
    metabolomics and evaluate the biological activities of Z. nemorale and B. heterotricha.
    For this purpose, extracts of leaves, stems, seeds and roots of B.
    heterotricha and leaves and stems of Z. nemorale, using hexane, acetate of
    ethyl and methanol. Essential oils were also obtained from the leaves of each
    of the plants. Antioxidant activity, total phenols and flavonoids content were
    determined using spectrophotometric methodologies. The activity
    antimicrobial activity was evaluated against Gram-positive, Gram-negative and
    fungi, using the broth microdilution method. The analyses
    Metabolomics were performed via UPLC-MS and GC-MS.
    For B. heterotricha, the methanolic extracts of leaves and roots showed the
    higher antioxidant activities and the highest value for total phenols. In turn, the
    Leaf acetate extract showed the highest flavonoid content. For Z.
    nemorale, the stem extract showed the highest antioxidant capacity and
    total phenol content, while the leaf acetate extract showed the highest
    flavonoid content. The leaf acetate extracts of both plants
    showed activity against most of the tested microorganisms, being the
    most active extracts of each of the plants. In the metabolomic analysis,
    identified secondary metabolites of several classes of natural products,
    such as: Flavonoids, phenols, lignans, coumarins, amides, fatty acids, compounds
    glycosylates, monoterpenes, sesquiterpenes, diterpenes and derivatives.
    The results of this study demonstrated that the plants Z. nemorale and B.
    heterotricha show promising antioxidant and antimicrobial properties,
    justifying its use for medicinal purposes in their community.

     
     
11
  • Êni de Souza Carvalho
  • Chemical and biological study of essential oils extracted from three Amazonian specimens of the Piperaceae family

  • Leader : ELIANE DE OLIVEIRA SILVA
  • MEMBRES DE LA BANQUE :
  • CALINE GOMES FERRAZ
  • ELIANE DE OLIVEIRA SILVA
  • FABIO DE SOUZA DIAS
  • IZABEL ALMEIDA ALVES
  • JORGE MAURICIO DAVID
  • RENATA BIEGELMEYER DA SILVA RAMBO
  • Data: 4 oct. 2023


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  • The current trend toward using natural food additives, cosmetics, and medicines has motivated industries to substitute synthetic compounds for natural products. Essential oils (EOs) from medicinal plants are a well-known source of chemical compounds that display several interesting biological activities, including antimicrobial action. In this study, we investigated the antibacterial activity of EOs extracted from three Piperaceae species collected in the Brazilian Amazon region against a representative panel of cariogenic bacteria. The minimum inhibitory concentration (MIC) of the essential oils extracted from Peperomia pellucida (PP-EO), Piper marginatum (PM-EO), and Piper callosum (PC-EO) was determined against Streptococcus mutans, S. mitis, S. sanguinis, S. salivarius, S. sobrinus, Enterococcus faecalis, and Lactobacillus casei by using the microplate microdilution method. PM-EO, PC-EO, and PP-EO displayed antibacterial activity against all the tested cariogenic bacteria. PM-EO displayed the best inhibitory activity, with MIC values ranging from 50 to 500 µg/mL. The lowest MIC values were obtained for PM-EO against S. mitis (MIC = 75 µg/mL), Lactobacillus casei (MIC = 50 µg/mL), and S. mutans (MIC = 50 µg/mL). Gas chromatography mass spectrometry (GC-MS) analysis allowed the chemical composition of all the EOs to be identified. The main constituents of PM-EO, PC-EO, and PP-EO were 3,4-(methylenedioxy)propiophenone, α-pinene, and dillapiole, respectively. Finally, the compounds that were exclusively detected in PM-EO are highlighted. Our results suggest that PM-EO may be used in products for treating dental caries and periodontal diseases

12
  • SUELEN AQUINO SANTOS
  • A theoretical study of weakly bound molecular complexes of the X-CO2 type (X = He, Ne, Ar, H2): Inclusion/correction of the dispersion effects in the potential energy curves with spectroscopic accuracy

  • Leader : ROBERTO RIVELINO DE MELO MORENO
  • MEMBRES DE LA BANQUE :
  • MARCOS ANTÔNIO DE CASTRO
  • ROBERTO RIVELINO DE MELO MORENO
  • TIAGO VINICIUS ALVES
  • Data: 16 nov. 2023


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  • The description of intermolecular interactions in the formation of small atomic/molecular complexes is fundamental for determining their properties and, consequently, for understanding physical, chemical and biological processes on a larger scale. In this dissertation, we compute the binding energy of intermolecular interactions of van der Waals (vdW) complexes of type X-CO2 (X = He, Ne, Ar, H2), as well as their Potential Energy Surfaces (PES). (I) We evaluate these interactions and CEPs from an ab initio point of view, using second-order Møller-Plesset perturbation theory (MP2) and extending to the Coupled Cluster CCSD(T) level, combined with correlated Dunning bases up to the limit complete base set (CBS). (II) We evaluate the consistency of the second-order scattering contribution compared to the CCSD(T)/CBS level. (III) Based on our results, we applied the ∆vdW dispersion correction proposed by TkatchenkoScheffler (TS-vdW) to the MP2 method (MP2 + ∆vdW), adjusting the medium- and longrange behavior of the studied complexes. (IV) We analyze the case of calibrated/corrected density functionals to describe vdW complexes, i.e., the HMDFT and DFT-D methods, comparing their performance to the results obtained with MP2/aug-ccpVQZ to CCSD(T)/CBS and with MP2 + ∆vdW. (V) We proposed a TS-vdW correction for HMDFT functionals and recalibrated some DFT-D functionals to describe the systems studied, using a methodology similar to that of TS-vdW. (VI) We then use the corrected PES to solve the Schrödinger equation associated with nuclear movement in the direction of dissociation. From the corrected PES, we calculated the equilibrium intermolecular distances (Re), harmonic vibrational frequencies (ωe), anharmonic correction (ωexe), equilibrium dissociation energies (De) and zero-point vibrational energies (∆ZPVE). Our results are compared and analyzed, based on semi-empirical parameterizations and available spectroscopic observations, and indicate that a better description of the stability of these weakly bound complexes requires the inclusion or correction of higher order dispersion terms, which are not present in the MP2 and HM-DFT levels and are often not included in DFT-D corrections either. 

13
  • FABRÍCIA DOS SANTOS LEAL
  • SYNTHESIS OF CYCLIC GUANIDINES CATALYZED BY BISMUTH SALTS
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • AMENSON TRINDADE GOMES
  • ANDRE ALEXANDRE VIEIRA
  • CALINE GOMES FERRAZ
  • JORGE MAURICIO DAVID
  • SABRINA TEIXEIRA MARTINEZ
  • SILVIO DO DESTERRO CUNHA
  • TIAGO LIMA DA SILVA
  • Data: 24 nov. 2023


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  • Organic synthesis is crucial in the construction and alteration of organic molecules, seeking conditions for a more practical, faster, and less harmful synthesis for the environment. One pot reactions are versatile, as there is no isolation of intermediates, reducing reaction time and the use of solvents in addition to providing good yields. Reactions in mechanochemistry and one pot microwaves are considered more sustainable syntheses compared to conventional methods. Guanidines are important molecules in organic synthesis since they perform important biological activities, serving as a building block for the synthesis of natural products, for accessing pharmacological drugs, and also as a catalyst for reactions. The use of long reactions, using catalysts and toxic solvents, with the use of protective groups, requiring further steps of protection and an inert atmosphere, is recurrent in the synthesis of guanidines. The present work extended the scope of the catalytic synthesis of cyclic guanidines using bismuth salts under the irradiation of a dedicated microwave reactor, in addition to the study of the synthesis of cyclic guanidines using a planetary ball mill. Microwave synthesis was performed using two methodologies: conventional and domino. The domino methodology proved to be more efficient, due to its practicality and reduction of bench time, in addition to obtaining better yields. Unpublished cyclic guanidines were accessed with moderate yields. The reactions using the mechanochemical reactor did not provide good yields, with 25% being the maximum yield obtained, however, it is efficient and attractive for the synthesis of this molecule, proving its reactivity in a solvent-free condition. Future improvements to this methodology are envisaged.

14
  • HUGO HENRIQUE DAVID DA SILVA SANTOS
  • USE OF GEOCHEMICAL INDEXES IN QUALITY ASSESSMENT ENVIRONMENTAL OF SURFACE SEDIMENTS COLLECTED IN THE BAY OF ALL SAINTS
  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • JOAO BATISTA PEREIRA JUNIOR
  • JORGE LUIS OLIVEIRA SANTOS
  • SERGIO LUIS COSTA FERREIRA
  • Data: 14 déc. 2023


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  • Given its vast extension and extraordinary biodiversity, Baía de Todos os Santos (BTS) has stood out in Brazilian territory since the beginnings of colonial Brazil. However, the human activities that have developed in its surroundings have been blamed for introducing chemical species into the environmental context that are potentially toxic to the biota present, creating a crucial problem to combat in the region. In this sense, the present work promoted assessing the environmental quality of surface sediments collected in the BTS by acquiring mathematical models known as geochemical indices. Therefore, eight chemical elements were determined in 30 sediment samples collected from scattered points of the BTS. The concentrations found were compared with guide values for the environmental quality of sediments (TEL and PEL). Additionally, geochemical parameters were obtained that estimated the levels of contamination present in the sedimentary material. None of the samples exceeded the PEL established by CCME; however, As, Cd, Cr, and Ni presented levels above the TEL, indicating possible contamination in the region. The geoaccumulation index (Igeo) showed high contamination for Cr (Igeo: 3.01 and 3.08), Cd (Igeo: 3.04; 3.26 and 3.54) and Ni (Igeo: 3.05; 3 .18 and 3.20). Zn showed extreme contamination in 8 samples (Igeo: 4.03, 4.07, 4.15; 4.17 and 4.30). Arsenic and vanadium presented the highest contamination factor (FC) values, indicating moderate contamination by these metals. On the other hand, by determining the pollution index (PI), it was observed that all species were responsible for causing pollution at all levels in the BTS. The pollution load index (PLI) and the modified degree of contamination (mCdeg) obtained were between 0.07-0.65 and 0.12-0.93. Furthermore, ecological risk indicators point to low-level risks caused by chemical species.

15
  • NICOLE EVELYN DE JESUS SANTOS
  • DEVELOPMENT OF ANALYTICAL METHODS FOR DETERMINING INORGANIC CONSTITUENTS IN SNACKS FOR DOGS AND CATS USING ATOMIC SPECTROMETRY
  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • Data: 14 déc. 2023


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  • This report describes the research activities developed by Nicole Evelyn de Jesus Santos, student of the Master's Course of the Postgraduate Program in Chemistry (PGQUIM) at the Federal University of Bahia since August 2022, under the guidance of Prof. Dr. Rennan Geovanny Oliveira Araujo.
16
  • MARCOS DIOGO SOUZA PEREIRA
  • USE OF A MICROSCOPIC CAMERA TO DETERMINE TOTAL Fe IN FRESH WATER BY DIGITAL COLORIMETRY IN SOLID PHASE

  • Leader : RODOLFO DE MELO MAGALHAES SANTANA
  • MEMBRES DE LA BANQUE :
  • ALLISON GONÇALVES SILVA
  • FABIO DE SOUZA DIAS
  • MADSON DE GODOI PEREIRA
  • VALFREDO AZEVEDO LEMOS
  • Data: 19 déc. 2023


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  • This work evaluates the total Fe concentration in drinking water by 1-(2- thiazolylazo)-2-naphthol (TAN) using C18 silica as solid support. For this purpose, a solid-phase digital colorimetry analytical method was developed. The image acquisition tool was a USB digital microscope 500x2 mp connected to a smartphone. The ImageJ software recorded and handled collected images in red–green–blue (RGB) color space. A flow system based on multi-commutation was employed to manage solutions to analysis. The physical and chemical parameters: (i) optical window diameter; (ii) pH (5.0 to 7.5); (iii) eluent solution concentration and volume (HCl 0.01 to 0.25 mol L-1; 150 to 400 µL, respectively); (iv) sample volume (100 to 300 μL); and (v) flow rate (0.8 to 2.0 mL min-1) were investigated and optimized. The microscope USB camera allowed the system to operate with a diameter of 0.1 cm for the optical Window, which led to 10 times solid support reduction (ca. 3.5 ± 0.1 mg) compared with the previously reported solid phase colorimetric methods. Furthermore, the obtained parameters were pH = 6.5, 350 μL of HCl 0.1 mol L-1, 250 μL of the sample, and a flow rate of 2.0 mL min-1 as optimized conditions for analysis. The proposed method showed a linear working range up to 1.0 mg L-1 (R= 0.9992) with detection (LOD) and quantification limits (LOQ) of 0.025 and 0.085 mg L-1, respectively. Drinking water samples were analyzed by the proposed method, and the observed Fe concentration found ranged from 0.17±0.05 to 0.44±0.01 mg L-1,  showing no statistically significant difference (p= 0.05) compared with the reference method.

17
  • Rafael Alves Campos
  •        

     
     ENHANCEMENT OF S-C3N4 H2 PHOTOCATALYTIC PRODUCTION BY CREATING CARBON QUANTUM DOTS
     
  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • LUCIANA ALMEIDA DA SILVA
  • RAILDO ALVES FIUZA JUNIOR
  • LILIAN LEFOL NANI GUARIEIRO
  • Data: 19 déc. 2023


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  •       

     
     Global climate change generated by the increasing and indiscriminate fossil fuels consumption requires innovative and immediate actions that materialize the energy transition and lead humanity on the path of sustainable development. Immersed in this context, we have developed photosensitive polymeric materials based on sulfur-doped polymeric carbon nitride (SPCN) capable of producing hydrogen in the presence of water, sunlight, and sacrificial reagents. With the aim of enhancing the photocatalytic activity of this material, we have devised a two-step synthesis. In the first step, small amounts of citric acid are added to thiourea, the precursor of the polymer, which is then calcined. In the second step, we thermally exfoliate the polymer obtained in the previous stage. The citric acid concurrently becomes carbon quantum dots (PQC) on the surface of the semiconductor material during the SPCN synthesis, enhancing light absorption and improving the photocatalytic production of H2. The materials were characterized using XRD, FT-IR, DRS, SEM, BET, and TEM. The XRD analysis confirmed the structure of polymeric carbon nitride and the pseudo-graphitic stacking in all prepared materials. Infrared absorption spectra also confirmed the presence of characteristic bands of functional groups in the PCN. Scanning and transmission electron microscopy analyses revealed the formation of exfoliated materials as well as the presence of carbon quantum dots. Both the presence of carbon quantum dots and sulfur doping altered the absorption profile of the samples in the visible region, contributing to narrowing  the band gap. The sample with a higher content of carbon quantum dots (SPCN-CD60-TES) exhibited the best photocatalytic activity, steadily producing 694 µmol h-1 g-1 of H2 over six hours when irradiated with a solar simulator. 
     
Thèses
1
  • Aline Santos de Almeida
  • Distribution of manganese and other trace elements in particulate matter fractionated by size, 
    Total Particulate - PTS and Breathable Particulate - PM2.5 in the area of influence of an Fe-Mn metallurgy.
     
     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • VANIA PALMEIRA CAMPOS
  • FRANCIELE OLIVEIRA SANTANA
  • MARIA CRISTINA SOLCI
  • SILVÂNIO SILVÉRIO LOPES DA COSTA
  • ELIZABETH DA ROCHA COUTO
  • Data: 7 févr. 2023


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  • Manganese ore is essential for the production of manganese-based ferroalloys and steel production in the steel industry. Despite being an essential element for man, acting in the formation of bones and tissues, reproductive function and metabolism of carbohydrates and lipids, chronic exposure to Mn mainly affects the central nervous system. Fe-Mn metallurgy is a potential source of emission of this metal and the knowledge of its distribution, as well as of other trace elements in atmospheric particle size ranges, is of great importance in characterizing the risk to which a population may be exposed. In this work, Mn and other trace elements (Co, Cd, Ni, Cu, Se and Pb) were determined in atmospheric particulate matter fractionated by size, total particulate matter - PTS and breathable particulate matter - PM2.5 at three points located in the municipality where is a metallurgy Fe-Mn (Simões Filho) and at a point located in Salvador-BA, Imbuí neighborhood, an urban area far from industry, in addition to a point in the rural area of Tobias Barreto-SE, considered a background station. Measurements were taken between March and October 2017. The following equipments were used to collect atmospheric particulate matter: cascade impactor, Berner type, with 6 (six) stages; Small Volume Sampler (APV) for particles up to 2.5 micrometers (PM2.5); Portable Medium Volume Sampler for Total Particles – PTS. The trace elements Mn, Ni, Cu, Se and Pb were determined in the particulate material fractionated by size using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), also being determined in the PTS and PM2.5 Co and Cd, in addition to those elements. Mn, as expected, showed higher average concentrations in the particulate matter sampled in the three different ways, at the stations closest to the metallurgy: Simões Filho – Área Urbana (F-AU), Cotegipe (COT) and Mapele (MAP). The fine fraction of particulate matter showed a high Mn percentage for all locations ranging from 71-85%, corresponding to 12 ng m

    -3

     at the IMBUÍ and Tobias Barreto (TB), background station to 561 ng m

    -3

     at the closest (1.4 km), downstream of the metallurgy (COT), exceeding the WHO recommendation (150 ng m

    -3

    ). At the IMBUÍ stations, in Salvador and TB (background station), Mn showed an average concentration lower than the quantification limit of the method in all size fractions of atmospheric particulate matter. The fine fraction of particulate matter sampled in the impactor (0.06-1.7 µm) showed an average percentage of quantified elements (Mn, Ni, Cu and Pb) in all locations ranging between 65% referring to Ni at the IMBUÍ station and 92 % referring to Pb in COT. With the exception of Ni, the atmosphere of the background station (TB), presented the lowest percentages for the other elements in the particulate matter fractionated by size. Mn presented in the PTS the highest average concentrations in SF-AU (112 ng m

    -3

    ), MAP (803 ng m

    -3

    ) and COT (1697 ng m

    -3

    ), being in the last two stations from 5 to 11 times above the limit recommended by the WHO. Also in PM2.5, this limit was exceeded in SF-AU and COT (155 and 537 ng m

    -3

    ), which may further aggravate the health of the population, due to the greater ease of penetration of smaller particles into the respiratory tract. Cd was only quantified in PTS and PM2.5 in TOC (5.7 and 6.3 ng m

    -3

    , respectively), both above the annual standard of 5 ng m

    -3

     established by the European Union, while Co only was quantified in PTS, MAP and COT with mean concentrations of 0.70 and 1.2 ng m

    -3

    . The highest concentrations of Pb in the PTS were found in the stations closest to the metallurgy, which ensures that this is its main source. Both in PTS and in PM2.5 Cu showed higher average concentrations in areas with urban influence (Simões Filho and IMBUÍ) and must also be related to vehicular emissions. The risk contribution profile (LCR) for the different locations showed that Cd is responsible for 100% of the total carcinogenic risk in relation to exposure to PTS, in the area of influence of metallurgy. Regarding PM2.5, Cd and Ni are responsible for 58% and 42%, respectively. Pb, considering PTS and Cd, considering PM2.5, showed a higher non-carcinogenic risk probability for all age groups (infants, children and adults), mainly in the urban area of Simões Filho and in Cotegipe, the closest sampling site and downstream of metallurgy. For Mn, no non-carcinogenic risk was found in any of the locations, despite the average concentrations above the WHO recommendation in PTS and PM2.5. The results also showed that adults are more susceptible to the probable risk of cancer than children and babies, certainly related to the exposure time considered for each age group. The highest average cancer risk calculated for the population was 6.69 x 10-6, found in Cotegipe associated with Cd.

     

     
     
2
  • Vanessa de Jesus Ferreira
  • REVERSE PHASE LIQUID-LIQUID MICROEXTRACTION FOR THE DETERMINATION OF METALS IN DIESEL OIL AND VEGETABLE OILS BY X-RAY FLUORESCENCE SPECTROMETRY

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • GISELE ANDRE BAPTISTA CANUTO
  • VALFREDO AZEVEDO LEMOS
  • MARIA DAS GRACAS ANDRADE KORN
  • CLEBER GALVAO NOVAES
  • ERIK GALVÃO PARANHOS DA SILVA
  • Data: 1 mars 2023


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  • X-ray fluorescence spectrometry (XRF) has been widely used for multielement determination in various samples. However, when quantifying inorganic species to trace amounts is required, separation and preconcentration procedures are often used to reduce interference and increase sensitivity. Liquid phase microextraction (LPME) is one of the most well-known and applied pretreatment techniques in various methods for analyzing traces due to its simplicity, speed, and ease of automation. The three main categories of LPME are single-drop microextraction (SDME), dispersive liquid-liquid microextraction (DLLME), and liquid phase microextraction of hollow fiber (HF-LPME). Two methods were developed using reversed-phase liquid-liquid microextraction (RP-LLME) combined with energy dispersion X-ray fluorescence spectrometry (EDXRF). The first method is based on vortex-assisted reverse-phase liquid-liquid microextraction (RP-VALLME) to determine Cu, Mn, Ni, and Pb in diesel oil samples by EDXRF. Nitric acid solution was the extraction phase. After centrifugation, the aqueous phase was placed into a filter paper disc for EDXRF determinations. The following variables were optimized: type of extraction phase solution (HNO3), extraction phase concentration (0.075 mol L-1), stirring time (45s), and sample volume (5.0mL). The limits of detection and enrichment factors were, respectively: 14 μg L-1 and 34 (Cu), 8 μg L-1 and 62 (Mn), 10 μg L-1 and 59 (Ni), and 7 μg L-1 and 64 (Pb). The method's relative standard deviation (RSD, %) for each element (200 μg L-1 and 400 μg L-1) ranged from 2.1 to 6.4%. The proposed procedure was efficiently applied to determine the four analyses in diesel oil samples. The second method used dynamic RP-LLME to prepare edible oil samples for subsequent determination of Cd, Cr, Mn, and Ni by EDXRF. The microextraction procedure is based on a system in which the donor phase flows through the extractor solvent contained in an extraction chamber. Then, the enriched phase is deposited in filter paper and subjected to detection. Type and concentration of extractor solution (HNO3 0.1 mol L-1), sample flow (10.0 mL min -1), and extraction time (15 min) were optimized parameters. The following limits of detection and enrichment factors were obtained, respectively: 6 μg kg-1 and 100 (Cd), 7 μg kg-1 and 65 (Cr), 8 μg kg-1 and 82 (Mn), and 11 μg kg-1 and 74 (Ni). The proposed method was applied to determine the elements in soybean, sunflower, corn, and canola oils samples. The results were compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP OES). The methods developed are an excellent alternative for determining elements in oil samples due to the advantages obtained, such as simplicity, speed, little waste generation, sensitivity, and the possibility of automation and miniaturization.

3
  • Fabrícia Nunes da Silva
  • DESIGN, SYNTHESIS AND STUDY OF NEW LUMINESCENT LIQUID CRYSTALS TRIAZINE-BASED

     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ANDRE ALEXANDRE VIEIRA
  • JULIANA ECCHER
  • VANESSA DO NASCIMENTO
  • HUGO ALEJANDRO GALLARDO OLMEDO
  • HARALD BOCK
  • Data: 6 mars 2023


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  • In this work, two series of discotic molecules were designed, synthesized and characterized, one symmetrical and the other non-symmetrical, both derived from the s-triazine heterocycle. The methodology used initially used the trimerization of benzonitriles in an acid medium and later the triphenyltriazine was functionalized with one, two or three arms of the phenanthryl or [4]helicenyl type from Perkin-Mallory reactions. The final molecules were designed with short-chain alkyl ester-type groups to induce glass transitions and also columnar mesomorphism. All compounds were characterized using spectroscopic and spectrometric techniques. The thermal properties of the final molecules were investigated by DSC, TGA, POM and XRD techniques.

    The phenanthryl- and helicenyl-substituted symmetrical triazine esters showed glass transitions conveniently above room temperature and within the hexagonal columnar liquid crystal phase, resulting in a solid columnar order at room temperature. Clearing points > 375°C were recorded for phenanthryl derivatives. For the ideal alignment of a liquid crystal, it is important that the melting and clearing temperatures are attainable, which was achieved only for the moderately non-planar symmetrical (> 205°C) helicenyl derivatives.

    To overcome this challenge, a second series of non-symmetrical molecules was prepared from the functionalization of triphenyltriazine with one or two phenanthryl or helicenyl arms but keeping the methyl benzoate group in the structure. Non-symmetrical triazines also showed hexagonal columnar liquid-crystalline behavior, but with lower melting points (< 290°C). Glass transitions were also observed at approximately 70, 50, 40 and 0°C for the non-symmetrical compounds, depending on the substitution pattern.

    The photophysical properties were evaluated for the symmetrical triazines in solution and solid phase. The materials showed absorbance between 272-342 nm and emission between 409-458 nm. The average quantum yield was 22% for phenanthryl derivatives and 12% for helicenyl. From the photophysical data it was possible to infer the energies of the first excited singlet state S1 of 3.31 eV for phenanthrenes and 2.95 eV for helicenes. DFT calculations showed good correlation between experimental and calculated energy values for S1 and allowed a good estimate for T1. The calculated values for the T1 orbital of the symmetric triazines are close to 2.5 eV, therefore, these materials can be considered as matrices for TADF emitters that emit light in the yellow-green range of the visible spectrum.

     
4
  • Abad Roger Castillo Hinojosa
  • EFFECT OF BENZAZOLIC HETEROCYCLES AND ALCOXY SUBSTITUENTS ON THE PROPERTIES OF FLUORESCENT CALAMITIC LIQUID CRYSTALS

     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ANDRE ALEXANDRE VIEIRA
  • RONAN BATISTA
  • TIAGO VINICIUS ALVES
  • ALOIR ANTONIO MERLO
  • FABRICIO GAVA MENEZES
  • Data: 14 avr. 2023


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  • This work describes the synthesis, characterization and study of novel organic molecules with liquid crystals properties. Liquid crystals are substances that preserve both liquid and solid behaviors, whose structures are generally made up of aromatic nuclei and linear aliphatic chains. LCs have technological applications as displays (e.g. LCD - Liquid Crystal Display), organic solar cells, analytical identification, thermometers, smart windows etc. Liquid crystals are important in controlling the passage of light and also show a low energy consumption.

    Heterocyclic compounds are important in the elaboration of liquid crystals, because they have polarized and asymmetric aromatic structures, this favors a low melting point. Benzazole LCs (benzene azole cycles) usually produce calamitic (rod-shaped) liquid crystals, due to their elongated geometry. Our research group, the Functional Molecular Materials Synthesis Group, have experience on the preparation and study of liquid crystals based on symmetrical and asymmetric conjugated benzazole structures in order to get scientific highlights and propose new applications.

    Asymmetric benzazole derivatives has been synthesized, such as: N-methyl benzotriazoles (BTZ), benzoxadiazoles (BOX), benzothiadiazoles (BTD) and benzoxazoles employing Suziki-Miyaura and Sonogashira cross-coupling reactions. Different linear aliphatic chains of the CnH2n+1 type (n = 6, 8, 10, 12 and 14) were used to favor mesomorphic entropy.

    Once the materials were characterized by IR, NMR and mass spectrometry, the thermal properties were studied by POM, DSC and XRD, where it was noticed that the predominance of the SmC / N phases for BOX and BTD, and SmX / SmA for BTZ depends on the heteroatom volume and the aliphatic chain size. TGA analysis determined that the structures are stable up to 360°C.

    Photophysical properties were studied by UV-Vis spectrophotometry, it noticed that the BTZ absorption band is maximum at 367 nm and the BOX and BTD bands have 60 nm red shift. The fluorescence intensity (radiative relaxation) it is twice greater in BTZ (blue emission) than BOX and BTD (yellow emission) systems. That explains why the quantum yield is more efficient for BTZ (63%) than the BOX and BTD conjugated systems (44%).

    Additionally, the study of benzoxazoles (the B series) with / without terminal alkoxy chain showed comparable luminescence with first series BTZ, but have the ordered SmC phase, which caused the absence of mesophase in B1. By that, the influence of group substitution and linear chain extension size on the liquid crystal properties was understood.

     
5
  • Ives Túlio Oliveira dos Santos
  • Theoretical study of photophysical properties of pi-conjugated systems: a computational approach

  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • JULIO COSME SANTOS DA SILVA
  • ANDRE ALEXANDRE VIEIRA
  • ELIANE DE OLIVEIRA SILVA
  • GABRIEL CHRISTIANO DA SILVA
  • MATEUS FERNANDES VENANCIO
  • ORLANDO ROBERTO NETO
  • TIAGO VINICIUS ALVES
  • YURI ALEXANDRE AOTO
  • Data: 24 avr. 2023


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  • .

6
  • Viviane Costa de Souza
  • β-CYCLODEXTRIN THIOGLYCOLIC ESTER DERIVATIVES APPLIED TO A NEW ACCESSIBLE CATALYST FOR SUZUKI-MIYAURA CROSS COUPLING REACTIONS AND SILVER NANOPARTICLE SYNTHESIS

     
     
     
  • Leader : MAURICIO MORAES VICTOR
  • MEMBRES DE LA BANQUE :
  • IARA DE FÁTIMA GIMENEZ
  • KLEBER THIAGO OLIVEIRA
  • MAURICIO MORAES VICTOR
  • RONAN BATISTA
  • VALERIA BELLI RIATTO
  • Data: 11 mai 2023


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  • Developing simple, selective, efficient and environmentally acceptable catalysts is one of the most important parts of organic synthesis, especially for cross-coupling reactions in forming C-C bonds. The Suzuki-Miyaura coupling reactions are among the most important cross-coupling reactions, but they are inefficient when looking for a reaction with low environmental impact, as they use organic solvents and toxic chemicals as well as the catalyst is difficult to recover. The use of water-soluble supramolecular structures, such as cyclodextrins, as ecologically friendly catalysts has been highlighted in recent years. In this project, a new palladium catalyst was developed, employing β-CD modified with thioglycolic acid and methylated thioglycolic acid as ligands through esterification reactions in a single step. Six different thiolate β-CD derivatives were synthesized (30a-c and 31a-c, yields between 92-97%) were synthesized to study the influence derivatives as ligands on catalyst activity. PdCl2 was chosen as the palladium source. The ligands and the catalyst were characterized by IR, 1H and 13C NMR, TGA, XRD, SEM, MET and mass spectrometry. The catalyst was synthesized in a simple method, in which the ligands and palladium were combined in degassed water at 100 °C for 20 minutes, obtaining palladium nanoclusters with an average diameter of 1.6 nm. This stock solution showed catalytic activity for Suzuki-Miyaura coupling reactions in aqueous medium between aryl halides and aryl boronic acids, using K2CO3 as base and in an open bottle. Different aryl halides were tested, including chlorides, with moderate to excellent yields (39-100%), employing a catalytic amount of 30a/PdCl2 (0.01 mol%). The catalyst can be reused twice before losing catalytic activity. The new catalyst was applied in the coupling reaction between iodinated C8 chrysine and commercial boronic acid, with a reaction time of 18 hours and yield of the new biaryl compound of 84%. The thiolate β-CD derivatives 30a-c and 31a-c were applied in the synthesis of silver nanoparticles, obtaining particles with a diameter of ~2.5 nm to ~35.0 nm, without the addition of reducing agents.

     
     
     
7
  • Benivaldo Nascimento dos Santos Junior
  • XANTHONES ISOLATED FROM THE STEM AND ROOT OF Kielmeyera coriacea (CALOPHYLLACEAE) AND EVALUATION OF THEIR ANTIMICROBIAL ACTIVITIES

     
  • Leader : ELISANGELA FABIANA BOFFO
  • MEMBRES DE LA BANQUE :
  • ELISANGELA FABIANA BOFFO
  • CALINE GOMES FERRAZ
  • LUCAS SILVA ABREU
  • DANIELLE FERREIRA DIAS
  • LOURDES CARDOSO DE SOUZA NETA
  • Data: 2 juin 2023


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  • This paper describes the isolation of five xanthones present in the roots and stem extract of Kielmeyera coriacea Mart. (Calophyllaceae) and the evaluation of the antimicrobial activity of these xanthones. The specimens were collected in Parque do Cercado in Chapada Diamantina - Bahia. The stem and roots of the plant were submitted separately to maceration in hexane and ethyl acetate, generating the respective hexanic and ethyl acetate extracts. The extracts, in turn, were subjected to several chromatographic processes, and an unpublished xanthone was obtained from the fractions of the ethyl acetate extract of the roots, in addition to an unpublished xanthone and three already known, having been obtained from the ethyl acetate extract from the stem. The substances were identified using spectrometric methods, such as one-dimensional (1H and 13C) and two-dimensional (gHMBC and gHSQC) Nuclear Magnetic Resonance and mass spectrometry. The antimicrobial activity of xanthones was evaluated by the broth dilution method, and one of the already known xanthones showed activity against Micrococcus luteus, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Candida albicans and one of the new xanthones showed activity against Micrococcus luteus

     
8
  • André Barreto Cunha
  • Occurrence, detection, quantification, and biological activities of triterpene acids and other components in different plant families

     
     
  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • ELIANE DE OLIVEIRA SILVA
  • VALERIA BELLI RIATTO
  • CLAYTON QUEIROZ ALVES
  • HUGO NEVES BRANDAO
  • Data: 22 juin 2023


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  • This study reported the importance of natural products in scientific development, such as triterpene acids, alkylphenols, and biflavonoids. Concerning triterpene acids, a methodology was developed for detecting and quantifying extracts of  Davilla rugosa Poir. et St. Hill (Dilleniaceae) and Eriope blanchetii  (Benth.) Harley (Lamiaceae). As a result, it can be observed that betulinic acid (AB) was obtained in considerable yields (~ 2.4 x 10-2 % of dry weight) in the stem of Drugosa as well as in the leaves of Eblanchetii (2.5 x 10-2 % of dry weight). In addition, oleanolic acid (OA) was determined in the petioles of the leaves (1.1 x 10-2% of dry weight) of Eblanchetii, and ursolic acid (AU) were identified as traces in all parts of the plant (leaves, petioles, stem, and root). Regarding the analytical validation, the chromatographic method used in the simultaneous quantification of these acids was selective and precise, presented satisfactory linearity, and, finally, the robustness and recovery values with acceptable limits. In addition, several chemical strategies for synthesizing AB (and bioactive analogs) from betulin were reviewed so that different derivatives exhibited antiplasmodial activity (compounds with modifications in the C-3 position, including dimeric derivatives), anti-Leishmania spp. (heterocycles and derived from amides in C-2/C-3) or antitrypanosomal (derivatives of amides in the C-28 position) superior to those corresponding to betulinic acid. In addition, a detailed review of the chemical composition, the different biological properties, technological and medicinal uses, and the most recent discoveries regarding the biosynthesis of alkylphenols (chemotaxonomic markers) in the Anacardiaceae family was carried out. Thus,  bioactive metabolites (essential oils, terpenoids, flavonoids and biflavonoids, chalcones, and alkyl phenols) have been isolated in different species and genera. Besides, different cosmetic and pharmacological compositions have been patented, and new mechanisms for the biosynthesis of phenolic lipids have been proposed, whose results highlight the relevance of this family for the Chemistry of Natural Products and related scientific areas.     

     

     
     
9
  • VILBERTO LAZARO MARTINS NASCIMENTO
  • Rietveld Refinement method for evaluation of CuCr2-xAlxO4 multicomponent catalysts applied to glycerol hydrogenolysis

  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • ARTUR JOSE SANTOS MASCARENHAS
  • JOSÉ MARCOS SASAKI
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • LUCIANA ALMEIDA DA SILVA
  • RAILDO ALVES FIUZA JUNIOR
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • VALERIA CRISTINA FERNANDES
  • Data: 30 juin 2023


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  • Heterogeneous catalysts are generally multiphase materials, in which one or more active phases are dispersed in a support, which is a material that guarantees greater surface area, thermal stability, better performance in catalytic reactions of industrial or environmental interest. The Rietveld refinement method is used for refinement of structures from X-ray diffraction or neutron diffraction data. Despite being a consolidated method for the interpretation of X-ray diffraction data in powders, only in the last 10 years the Rietveld refinement are being used in Heterogeneous Catalysis to solve the structure of multiphase catalysts and to quantify these phases, but its use is still limited. The objective of this work is to apply the Rietveld method in multiphase copper and chromium catalysts, which are used in the hydrogenolysis of glycerol reaction, to obtain crystallographic data. For this crystallographic study, aluminum-substituted copper chromites CuCr2-xAlxO4 (x = 0 - 2.0), prepared by the urea combustion method, had their X-ray diffractograms collected with parameters suitable for analysis by the method Rietveld. Two programs were used: one for crystallographic phase identification (X'pert HighScoreTM) and other for phase refinement (GSASTM). In most refinements, the type 1 function (Shifted Chebyschev) was used, with terms ranging from 6 to 10 terms for background adjustment. The refinements were conducted, the sequences of parameters annotated, and the results obtained were considered satisfactory when the adjustment parameters (c2 near 1 and Rf2 less than 5%). All samples showed at least 4 different crystallographic phases, namely tenorite (CuO), chromium (III) oxide (Cr2O3), McConnellite (CuCrO2) and copper chromite (CuCr2O4). In the case of the sample with x = 2.0, alumina (Al2O3) and delafossite (CuAlO2) phases were also observed. These phases were quantified and had their crystallographic parameters defined. Based on the refined results, the crystallite sizes of the respective phases were determined and the possibility of insertion of the aluminum into the lattice of the chromium containing phases was investigated. The data were correlated with the catalytic activity in the hydrogenolysis of glycerol to 1,2-propanediol.

10
  • Darllen Guimarães da Silva
  • CO2-assisted methanol conversion over V/H-ZSM-5 catalysts

     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • HELOYSA MARTINS CARVALHO ANDRADE
  • LUCIANA ALMEIDA DA SILVA
  • FABIO DE SOUZA DIAS
  • ARTUR JOSE SANTOS MASCARENHAS
  • RODRIGO DE PAULA
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 3 juil. 2023


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  • Carbon dioxide assisted methanol conversion was studied on V/H-ZSM-5 bifunctional catalysts. The catalysts were prepared by wet impregnation of NH4VO3 on H-ZSM-5 (Zeolyst, SiO2/Al2O3 = 23) in order to obtain vanadium contents of 1.0, 2.5 and 5.0%. The catalysts were tested in methanol conversion assisted by O2 or CO2 as oxidizing agent. In inert medium (He atmosphere) it was observed that the catalysts lead to the selective production of DME (X = 74.4%, Y = 55.4%), at a temperature of 220°C. In the presence of O2 (CH3OH/O2 = 3:1) preferential formation of DMM (X = 84.1%, Y = 49.5%) is observed at a temperature of 220°C, but there is formation of small amounts of other by-products (dimethyl ether, formaldehyde, methyl formate, CO and CO2). Furthermore, partial deactivation of the catalyst due to the formation of carbonaceous deposits is observed. When assisted by CO2 (CH3OH/CO2 = 3:1) DMM formation (X = 83.8%, Y = 62.3%) is observed at the same temperature and a CO2 conversion of 4.2%, without significant losses of activity with the reaction time and a formation of only 2.6% of carbonaceous residues. The formation of other products only occurs at temperatures above 240°C. An increase in DMM yield is observed with increasing vanadium content up to 5%.

     
11
  • Sidimar Santos Oliveira
  • RARE EARTH ELEMENTS IN ROAD DUST COLLECTED IN THE METROPOLITAN AREA OF SALVADOR: METHODOLOGIES, ENVIRONMENTAL AND HEALTH RISK ASSESSMENT

  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • TATIANA DILLENBURG SAINT’PIERRE
  • EDUARDO SIDINEI CHAVES
  • MARIA TEREZA WEITZEL DIAS CARNEIRO LIMA
  • JOAO BATISTA PEREIRA JUNIOR
  • LETÍCIA MALTA COSTA
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • SARAH ADRIANA ROCHA SOARES
  • TARCISIO SILVA DE ALMEIDA
  • TATIANE DE ANDRADE MARANHÃO
  • VANIA PALMEIRA CAMPOS
  • Data: 5 juil. 2023


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  • The objective of this work was to develop and optimize road dust sample preparation procedures for the determination of rare earth elements (REE) using spectroanalytical techniques, with emphasis on reducing the use of hazardous reagents and sample preparation time, in addition to elimination of spectral and non-spectral interference, such as investigations in the chosen instrumental techniques, aiming to evaluate the REE in terms of occurrence, distribution, fractionation and identification of possible sources in road dust samples collected in the Metropolitan Region of Salvador (MRS). In the first work, the determination of Yb in samples of road dust was proposed, using a simple and fast methodology, based on the preparation of the sample as slurry and analysis by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GF AAS) and optimized using the Doehlert design. The temperatures applied to the graphite furnace were optimized, wherein the pyrolysis and atomization temperatures were 1200 °C and 2700 °C, respectively, using 250 μg of W as permanent chemical modifier. The limit of detection (LOD) and limit of quantification (LOQ) were 22 and 72 ng g−1, respectively, with characteristic mass of 6.0 pg. The accuracy of the analytical method was confirmed through analyzes of three certified reference materials (CRM): trace elements in soil containing lead from paint (NIST 2586), rock (NCS DC 73301) and geochemical soil (TILL-1), and good agreement was obtained between 99 (± 4) and 104 (± 2%) for found and certified values. The analytical method was applied to Yb determination in eight samples of road dust collected in urban area of Salvador and Jaguaquara, Bahia State, Northeast, Brazil. The concentrations obtained for Yb ranged from 172 (± 13) to 2065 (± 122) ng g−1. Thus, the proposed analytical method presents the characteristics of being fast, accurate and precise for the determination of Yb in road dust samples, employing slurry sampling and detection by HR-CS-GFAAS. In the second work, studies were carried out to optimize the experimental conditions of procedures proposed for the determination of REE by ICP OES and ICP-MS. The Doehlert matrix was applied to optimize the operating conditions of the ICP OES, using the nebulization gas flow rate and radiofrequency power as variables, and the REE signal/noise ratio as multiple response. Four analytical procedures were evaluated for accuracy using rock certified reference material (NCS DC 73301). Procedure D showed no statistically significant difference between the found values and the certified values for REE at a 95% confidence level. The limit of quantification obtained varied between 0.10 (Y) and 1.1 mg kg-1 (Ce) by ICP OES and between 0.36 µg kg-1  (Pr) and 0.021 mg kg-1 (Eu) by ICP-MS. The accuracy of the procedure was confirmed through the analysis of four CRM: rock (NCS DC 73301), fly ash (BCR 176R), estuarine sediment (BCR 667) and road dust (BCR 723), and through the comparison of methods (ICP OES and ICP-MS). The concentrations obtained varied between <LOQ for Lu and 171 ± 2 mg kg-1 for Ce. In the third work, samples of road dust from the Metropolitan Region of Salvador were analyzed and, according to the statistical tests employed, the finer fraction (fraction C <38 µm) showed significantly higher concentrations than fraction B. Cross-Validation (LOOCV) was used to verify and compare the accuracy of the Inverse Distance Weighting (IDW) and Empirical Bayesian Kriging (EBK) spatial interpolation methods in predicting REE and PTE enrichment factor data in 20 road dust samples from Metropolitan Region of Salvador, and with that, spatial distribution maps of REE and potentially toxic elements (PTE) were constructed in order to identify possible contaminated areas. The sites of Simões and Candeias presented the highest enrichment factor (EF) and geoaccumulation index (Igeo) for REE, Ba, Co, Mn, Pb, U and Zn, whereas the site of Dias d'Ávila presented a high enrichment by Cu. The sum of REE concentrations and Ba and Co concentrations decrease with increasing distance to the Fe-Mn metallurgical plant in the first 10 km together with Mn. It was evidenced that the primary source of Cu and Mn are the Copper and Fe-Mn metallurgical plants, respectively. Rare earth element concentrations were normalized by Post-Archean Australian Shale (PAAS) and North American Shale Composite (NASC) for the C fraction (<38 µm) of road dust from four sample points in the study area, namely: Salvador (SA), Simões Filho (SF1), São Sebastião do Passé (SP2) and Dias d'Ávila (DD1). Rare earth element patterns normalized by PAAS and NASC showed that samples from the region farthest from the Fe-Mn metallurgical plant showed enrichment of LREE over HREE, as expected. The samples from the regions closest to the metallurgical plant or which were downwind showed an enrichment of the MREE over the HREE. Cerium and Eu positive anomalies were also observed in the SF1 sample near the metallurgical plant, indicating that anthropic activities such as metallurgy can change the distribution pattern of REE via the adsorption and oxidation processes of these elements. The assessment of carcinogenic (CR) and non-carcinogenic (HI) risk, for samples from Simões Filho and Candeias, Dias d'Ávila and Camaçari, considering both children and adults, showed CR and HI values below the limit considered tolerable for REE, indicating a safe environment for REE exposure in road dust. The lifetime average daily dose (LADD) values of REE were higher in the samples from Simões Filho and Candeias than from Dias d'Ávila and Camaçari, evidencing a greater exposure to REE for the population surrounding the Fe-Mn metallurgical plant. Samples from Simões Filho and Candeias showed a HI value for Mn greater than unity for adults and children, indicating that there are risks of adverse effects on human health, especially for children and through exposure routes of dermal absorption and particle ingestion of road dust.

12
  • AMANDA SANTOS GUSMÃO
  • Alterations in the metabolic profile of endophytic fungi isolated from Euphorbia umbellata for the production of bioactive substances

     
  • Leader : ELIANE DE OLIVEIRA SILVA
  • MEMBRES DE LA BANQUE :
  • ELIANE DE OLIVEIRA SILVA
  • JORGE MAURICIO DAVID
  • CALINE GOMES FERRAZ
  • ADEMIR EVANGELISTA DO VALE
  • MARCELO SANTOS CASTILHO
  • Data: 11 juil. 2023


  • Afficher le Résumé
  • Endophytic fungi live in association with plants and contain many clusters for the biosynthesis of special metabolites. Some of these genes are not expressed when the microorganism is cultured in vitro and appears silent. Several approaches can be put into practice in an attempt to activate these silenced genes. Among them, cultivation strategies with principles conceptualized in the expression “one strain, many compounds” (OSMAC) refer to the modulating effect that changes in culture conditions exert on the activation of the biosynthesis of different metabolites by a single endophytic strain. This work describes alterations in the in vitro metabolic profiles of endophytic fungi isolated from Euphorbia umbellata aiming the isolation or detection of bioactive substances. In the first chapter, a metabolomic study was carried out through the statistical treatment of the data obtained by UHPLC-TOF/MS-MS analysis of 36 samples, including fungal extracts from mixed and axenic cultures, with and without addition of salts, and also crude extracts from the host plant leaves. Score splot graphs of the PCA model and heatmaps were analyzed, and it was possible to observe through the PCA that there are certain similarities between the samples of fungal extracts and the leaves of the plant. The heat maps made it possible to infer about the production of substances by the endophytes that were also present, albeit in low concentration, in the plant extracts. The second chapter describes the isolation and structural characterization of three lactones isolated from cultures of the endophytic strain Aspergillus pseudonomiae J1. The isolation was guided by in silico methods for rational orientation of its screening in bioassay. All lactones showed in vitro activity against the epimastigotes and trypomastigotes of Trypanosoma cruzi. Notably, (+)-phomolactone IC50 values were lower than benznidazole (0.86 vs. 30.78 μM against epimastigotes and 0.41 vs. 4.88 μM against trypomastigotes). Target-based studies suggested that the lactones exhibited their trypanocidal activities due to inhibition of T. cruzi glyceraldehyde-3-phosphate dehydrogenase (TcGAPDH), and the binding free energy for all three TcGAPDH-lactone complexes suggested that (+)- phomolactone has a lower score (3.38), corroborating the IC50 assays.

     
13
  • Graziele de Araújo Carvalho
  • Photodegradation Study of Pesticides of Different Chemical Classes and the Influence of Physical-chemical Parameters

  • Leader : PEDRO AFONSO DE PAULA PEREIRA
  • MEMBRES DE LA BANQUE :
  • FREDERICO DE MEDEIROS RODRIGUES
  • GISELE OLIMPIO DA ROCHA
  • JEANCARLO PEREIRA DOS ANJOS
  • LUCIANA ALMEIDA DA SILVA
  • MARIA ELISABETE MACHADO
  • PEDRO AFONSO DE PAULA PEREIRA
  • RICARDO LEAL CUNHA
  • SABRINA TEIXEIRA MARTINEZ
  • Data: 28 juil. 2023


  • Afficher le Résumé
  • The characteristics of water are significantly altered by pollution. Contaminants, such as pesticides, impact surface and groundwaters, compromising their quality and causing adverse effects on the health of populations. Pesticides are pollutants that can be present in water and are derived from agricultural activities. Once in the aquatic environment, pesticides can undergo a series of interactions and their persistence will depend on their transformation kinetics, which, in turn, depends on their physicochemical characteristics and environmental factors. This work aimed to study the photodegradation process, in aqueous medium, of three pesticides, belonging to different chemical classes, namely: fenthion, bifenthrin and azoxystrobin. The influence of the initial concentration and the physicochemical parameters pH, radiation power and the addition of metals was evaluated. In order to analyze the solutions, a method was developed, validated and applied, and was based on Dispersive Liquid Microextraction (DLLME) and analysis by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The extraction optimization was performed by the Fractional Factorial design, involving the factors type and volume of the extracting solvent, type and volume of the dispersing solvent, pH, salting out effect and centrifugation time. The evaluation of the variables that significantly influenced the extraction process was made by the Doehlert Matrix planning and the adjusted values were: chloroform as extractor (400 μL); methanol as disperser (240 μL); pH = 7.0; addition of 0.8g of salt and centrifugation for 2 minutes at 3000 rpm. The optimized method showed a good performance in the parameters selectivity, limits of detection and quantification, linearity, precision and accuracy. The degradation study showed that, among the pesticides studied, fenthion was the pesticide which showed the most effective degradation in the experiments performed. The degradation was directly affected by the concentration of pesticides, the power of the incident radiation, the addition of metals and the quality of the water used in the solutions, while the pH did not significantly influence the degradation rates. The toxicity of pesticides and their dynamics in the environment make it necessary to monitor the presence of these compounds in water, to control their potability and quality for consumption.

14
  • Leonardo de Oliveira Aguiar
  • SYNTHESIS OF COUMARIN, CHALCONE AND NEOFLAVONOID DERIVATIVES WITH POTENTIAL BIOLOGICAL ACTIVITIES
     
  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • MAURICIO MORAES VICTOR
  • VALERIA BELLI RIATTO
  • CALINE GOMES FERRAZ
  • ADEMIR EVANGELISTA DO VALE
  • VANDERLUCIA DOS ANJOS CRUZ
  • CLAYTON QUEIROZ ALVES
  • JOSEAN FECHINE TAVARES
  • Data: 31 juil. 2023


  • Afficher le Résumé
  • Flavonoids and coumarins are defined as classes of specialized metabolites, present in plants from different families. The relevance of the study concerning flavonoids and coumarins is because compounds from these classes have considerable biological and pharmacological activities. The diversity and quantity of studies published annually on both classes of compounds corroborate the scientific importance of these polyphenols. In order to expand knowledge and contribute to the specialized literature, this PhD thesis proposes the synthesis of new ester derivatives of coumarins, as well as the development of a new methodology for obtaining flavonoids, especially chalcones and neoflavonoids, for further investigation on their pharmacological properties. Fifteen (15) coumarin esters were prepared via greener Steglich reaction, with yields between 15 and 93%. Ten (10) of them were synthesized for the first time. Coumarin derivatives were evaluated on their cytotoxic and antimicrobial potential. In addition, ten (10) compounds from the class of flavonoids were prepared, in a study of different phenols reactivity against cinnamic acid in the presence of BF3.OEt2. This study allowed access chalcones, flavanone and neoflavonoids, obtained from the substrate’s structural differences. Yields in this synthesis varied between 10 and 67%, and the products obtained were evaluated on their cytotoxic potential. This thesis will also present preliminary results of synthesis of hybrid compounds, formed by the combination between the coumarin moiety and other bioactive molecules, such as geraniol and tacrine.

     
15
  • Juliana Azevedo da Paixão
  • CHEMICAL CHARACTERIZATION, BIOLOGICAL ACTIVITIES AND TECHNOLOGICAL PROSPECTION OF Ananas comosus variations FROM THE PINEAPPLE BAG. 

     
  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • ELIANE DE OLIVEIRA SILVA
  • FABIO DE SOUZA DIAS
  • ADEMIR EVANGELISTA DO VALE
  • ERIKA MARIA DE OLIVEIRA RIBEIRO
  • Data: 18 août 2023


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  • The Bromeliaceae family comprises a vast diversity of species, with Brazil accounting for approximately 40% of this total. Some plants in the family have medicinal properties and are used in the treatment of numerous conditions and they are also used as food. The Active Pineapple Germplasm Bank (BAG-Pineapple) of Embrapa Cassava and Fruit is the largest germplasm bank of pineapples in the world, contributing to the selection of genotypes of agronomic, ornamental, and industrial value. This research aimed to carry out a survey of the chemical substances isolated and/or identified in the leaves of Ananas comosus, to analyze the pharmacological activities described in the literature, to prospect patents for products based on  Ananas comosus  and to perform a comparative phytochemical study of varieties of A. comosus from BAG-Pineapple. According to the literature, the presence of organic acids, flavonoids, esters, steroids and other metabolites, mainly phenolic compounds, and flavonoids, have been described. These substances have several pharmacological activities, especially abortive, antioxidant, lipid-lowering and hypoglycemic activities. The main patents filed are related to medicinal use, such as antineoplastics, anti-inflammatory drugs and drugs for the gastrointestinal tract. Regarding the phytochemical screening of A. comosus access leaves, the presence of special metabolites was evidenced, mainly phenolic compounds, flavonoids and saponins. The methodology validation and quantification of p-coumaric acid and ferulic acid were performed, p-coumaric acid contents were found between 24.83-881.65 μg/mg of extract and ferulic acid between 15.68-971.30 μg/mg of extract. In the phytochemical study of Ananas comosus var. erectifolius  the substances lupeol, stigmasterol, β-sitosterol, daucosterol, quercetin, p-coumaric acid, ferulic acid and a semipurified fraction with the presence of ellagic acid were identified and isolated. It is noteworthy to pointing out that this is the first study to identify and isolate these substances in Ananas comosus var. erectifolius, and the first to identify/isolate lupeol and ellagic acid in Ananas comosus. Thus, it contributes to the characterization of the chemical substances present  in the leaves of A. comosus of the  BAG-Pineapple and provides relevant information for the study of the pharmacological activity and the potential application in the pharmaceutical industry.

     

     

     
16
  • KLAUBER VIANA CARDOSO
  • Chemical composition of the roots of  Bowdichia virgilioides (Leguminoseae)

  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • VALERIA BELLI RIATTO
  • RONAN BATISTA
  • JORGE MAURICIO DAVID
  • BRUNO OLIVEIRA MOREIRA
  • MARIA DE FATIMA VANDERLEI
  • Data: 18 août 2023


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  • Bowdichia virgiliodes Kunt. is a medium-sized tree, comprised in the Papilionoideae subfamily and belonging to the Leguminoseae family. The species composes the flora in an endemic way among the tropical forests of South America and is popularly known as sucupira in several regions of Brazil, with predominance in the state of Bahia. The Bowdichia genus is contained in a set of high chemical and pharmaceutical potential, which have been explored over the years, but which depend on greater protection and investigative chemical studies. Its use in traditional medicine includes stem barks with tonic, antidiarrheal, antiulcerative, hypoglycemic, rheumatological properties and seeds acting as a dermatological antimicrobial, for example. The production of alkaloids by this plant may represent evidence of the parental relationship with other genera belonging to the Leguminoseae family. Thus, this work was proposed for the phytochemical study of the root of the species Bowdichia virgiloides using column chromatography to analyze the methanolic, hexanic, ethyl acetate and butanolic extracts. Triterpenoid compounds were identified, such as lupeol, stigmasterol and sitosterol, plus a hopan triperpene, the 17β-H-Δ21 hopan. The latter is not yet described in the species and also not evidenced in the genus. Among the flavonoids identified, it should also be noted the 7,3'-dihydroxy-4'–methoxyisoflavone (BV-1A), 7,5,4'-trihydroxyisoflavone (BV-1B); 2'- hydroxy-4',6',3,4-tetramethoxyhalcone (BV-5) and 7,2'-dihydroxy -4'-methoxyisoflavone (BV7) isolated from the methanolic phase; plus compounds (5,7-dihydroxy-4'-methoxyisoflavone) (EBV-2), 5,7,3-trihydroxy-4'-methoxyisoflavone (EBV-5D), 7,4'-dimethoxy-5-hydroxyisoflavone (EBV-7); 7,2',4'-trihydroxy-5,3-dimethoxy-flavan (EBV-13A), 7,4-dihydroxy-7- methoxy-flavan (EBV-13B); 5,7,4'-trihydroxy-8-glycoflavone (EBV-14); 5,7,4'-trihydroxy-3'- glycoflavone (EBV-22A). isolated from the ethyl acetate phase and which had not yet been cited in the species. Other flavonoids cited in the literature as originating from the species B. virgilioides could be confirmed as formononetin and pseudobaptigenin. However, in the present study, no alkaloids cited as common in the species were found. The structural determination of the substances was performed by mass spectrometric technique and infrared spectroscopy, nuclear magnetic resonance and comparison with literature data

17
  • Maiara Oliveira Passos
  • .

     
     
  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • MATEUS FERNANDES VENANCIO
  • ROBERTO RIVELINO DE MELO MORENO
  • TIAGO VINICIUS ALVES
  • GUILHERME AUGUSTO FERREIRA
  • MARCOS MALTA DOS SANTOS
  • ELIEL GOMES DA SILVA NETO
  • FERNANDO DE BRITO MOTA
  • FRANCISCO CORRETO BOLIVAR MACHADO
  • YURI ALEXANDRE AOTO
  • Data: 25 août 2023


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  • .

     
     
18
  • Maiara Oliveira Passos
  • Protonic transfer reactions involving aliphatic ketones: a systematic evaluation of conformational flexibility and torsional anharmonicity.

     
  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • TIAGO VINICIUS ALVES
  • ROBERTO RIVELINO DE MELO MORENO
  • MATEUS FERNANDES VENANCIO
  • ELIEL GOMES DA SILVA NETO
  • FRANCISCO CORRETO BOLIVAR MACHADO
  • Data: 25 août 2023


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  • This work proposes a theoretical study on protonic transfer reactions in the gas phase involving aliphatic ketones. The conformational flexibility and torsional anharmonicity were systematically evaluated for reactants and transition states associated with the hydrogen abstraction reactions from 2-butanone, 2-pentanone, and 3-penten-2-one by an H radical. Electronic structural methods, especially the density functional theory in comparison with the coupled-cluster method, were used to obtain the equilibrium geometries, conformational analysis, and the thermal rate constants determination. Furthermore, kinetics approximations derived from the Transition State Theory were used for thermal rate constants obtentions. Quantum effects were evaluated according to the small-curvature tunneling model. The set of functional/basis that showed the less mean absolute error was M06-2X/6-31+G(d,p). The conformational search has as a result 24, 64, and 22 conformers for the reactions involving the 2-butanone, 2-pentanone, and 3-penten-2-one, respectively. The results for the thermal rate constants indicate that the Single Structure
    Transition State Theory (SS-TST) overestimated all the thermal rate constants as well as the product branching ratio. The estimations obtained with the Multipath Transition State Theory including the corrections from the anharmonicity due to the torsional modes, represent the more accurate kinetic description for the studied reactions, therefore representing the most reliable results.

     
19
  • Wellington Correia de Carvalho
  • EVALUATION OF THE USE OF DRUGS FOR CHRONIC CARDIOMETABOLIC DISEASES IN THE BIOACCESSIBILITY OF ESSENTIAL ELEMENTS IN NUTRITIVE FLOURS

     
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MARIA DAS GRACAS ANDRADE KORN
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • WALTER NEI LOPES DOS SANTOS
  • DANILO JUNQUEIRA LEÃO
  • LAÍS ARAÚJO SOUZA
  • DÉBORA DE ANDRADE SANTANA
  • Data: 31 août 2023


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  • Simultaneous administration of drugs with food may compromise the bioaccessibility and absorption of nutrients. The aim of this study was to evaluate the influence of the use of losartan potassium, metformin hydrochloride and simvastatin on the in vitro bioaccessibility of micronutrients (Cu, Fe, Mn and Zn) in nutritious flour sold in Bahia, Brazil. The experimental procedure consisted of the in vitro extraction of the bioaccessible fraction of Cu, Fe, Mn and Zn in flours – with and without Losartan Potassium (50 mg), Metformin Hydrochloride (500 mg) and Simvastatin (20 mg) – using the Unified Method of Bioaccessibility (UBM), simulating the conditions of the gastrointestinal tract. For the decomposition of the samples (nutritive flour and residue) a digester block with a closed system was used. To determine the total (flour and residual fraction) and bioaccessible content of micronutrients, inductively coupled plasma optical emission spectrometry (ICP OES) was used. For oat flour, the bioaccessible contents (µg g-1) without the addition of drugs were: Cu 5.86 ± 0.21; Fe 32.80 ± 1.32; Mn 87.90 ± 1.90; Zn 30.33 ± 2.05, with bioaccessibility ranging from 31.5 for Fe to 99% for Mn. The in vitro extraction method was validated by mass balance, with recovery values from 89.78% for Cu to 101.94% for Mn. The range of bioaccessible contents (µg g-1) were: Cu (< 4.14), Fe (32.10 ± 0.20 – 54.10 ± 2.03), Mn (81.40 ± 0.93 – 93.22 ± 0.80) and Zn (< 10.80 – 29.11 ± 2.20). The estimate of the bioaccessibility of Cu, Mn and Zn in oat flour was compromised in the presence of Losartan Potassium, Metformin Hydrochloride and Simvastatin (p < 0.05). Thus, we can infer that chemical interactions can occur between drugs and micronutrients. Therefore, the results highlight that these drugs can interfere with the bioaccessibility of Cu, Fe, Mn and Zn in flours, in patients who use these drugs, suggesting their rational use in future investigations.

     
20
  • Rosiene Reis Mattos
  • Application of eugenol in the synthesis of new heterocycles, Schiff bases and analogues using mono and bidirectional reactions and study of antioxidant activity

     
     
     
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • VALERIA BELLI RIATTO
  • SILVIO DO DESTERRO CUNHA
  • ELIANE DE OLIVEIRA SILVA
  • CECILIA MARIA ALVES DE OLIVERA
  • CLEONIA ROBERTA MELO ARAUJO
  • VANDERLUCIA FONSECA DE PAULA
  • Data: 1 sept. 2023


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  • The constant development of new compounds with active biological properties boosted this work, with the aim of synthesizing new molecules from eugenol, as it is an abundant natural product and renewable source. Structural modifications were made to the eugenol molecule to form some classes of compounds, the vast majority of which are nitrogenous, such as twelve new Schiff bases, five hydrazones and two acetylhydrazones and coumarins, using microwaves, and with yields between 14 and 93%. New Twin compounds were produced with units of imines and 1,3-benzoxazines, composing a scope with six bis-imines and six bis-benzoxazines with yields between 15 and 90%. To evaluate the structure-activity relationship and the oxidative potential of the compounds, computational analyzes were carried out with the programs Molinspiration and Osiris, and the analysis of antioxidant activity with DPPH, revealing a significant increase in the oxidative potential of bis-1,3-benzoxazines derived from eugenol , when compared to eugenol.

     
     
     
21
  • OSCAR CAETANO DA SILVA NETO
  • Bergenin extraction from Pelthoporum dubium roots using multivariate optimization by assisted microwave extraction and molecularly imprinted polymer

     
  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • RONAN BATISTA
  • RENATA BIEGELMEYER DA SILVA RAMBO
  • LUCIANA LUCAS MACHADO
  • CLAYTON QUEIROZ ALVES
  • Data: 6 oct. 2023


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  • This work presents a contribution to the development of new methods for extracting and isolating bergenin from the roots of Peltophorum dubium (Fabaceae). From collected samples of the plant, bergenin was extracted using the usual techiniques and chromatographic methods, and then the yield obtained was compared with MAE. In addition, bergenin was used as a mold molecule for synthesizing the molecularly imprinted polymer. Next, from a trunk of P. dubium, whose dendrological analysis indicates that it is 31 years old, an analysis was carried out using HPLC/DAD and gallic acid and bergenin were quantified in each growth ring, corresponding to each year of the tree's life. The HPLC analysis method was validated for bergenin and gallic acid, its precursor. The yield of bergenin obtained using maceration, precipitation and silica gel chromatography was 3.62% in relation to the crude extract and 8.39x10-2% in relation to the mass of the roots. The microwave-assisted extraction of bergenin was optimized using different experimental conditions and experimental designs. Only the use of MeOH as a solvent revealed better extraction capacity compared to the EtOH/H2O mixture; the other experimental conditions were not significant. In addition, the MAE technique presented better yield (7.11%) in in comparison with conventional procedures besides less time consuming and solvent consumption. Concerning to  the dendrochronological analysis of the trunk of P. Dubium, it was found that individuals enter the related growth rings between 11th  and 14th. years have a higher amount of the compound, with a yield of 0.198% in relation to the mass of the crude extract. When developing the molecularly imprinted polymer (MIP), it can be verified that bergenin preferentially adsorbed on the MIP, when compared to non-imprinted polymers, as evidenced by the highest adsorption value in the entire analyzed range (10 to 100 µg/mL), in addition to to extract 84.54% of the bergenin contained in the extract sample, suggesting that MIP can be used as a basis for new methods of isolating bergenin. O presente trabalho apresenta uma contribuição significativa para o desenvolvimento de novos métodos para extração e isolamento de bergenina das raízes de Peltophorum dubium (Fabaceae). Utilizando-se de amostras da planta este metabólito foi extraído empregando métodos de extração e cromatográficos usuais e, em seguida o rendimento obtido foi comparado com MAE. Além disso, bergenina foi empregada como molécula molde para síntese do polímero molecularmente impresso. Em seguida, a partir de um caule de P. dubium, cuja análise dendrológica demonstra possuir 31 anos, foi realizado uma análise utilizando-se HPLC/DAD e ácido gálico e bergenina foram quantificados em cada anel de crescimento, correspondendo a cada ano de vida da árvore. Para as análises, o método de análise por HPLC foi validado para a bergenina e ácido gálico, seu precursor. O rendimento da bergenina, obtido empregando-se maceração, precipitação e cromatografia em sílica gel foi de 3,62% em relação ao extrato bruto e 8,39x10-2% em relação à massa das raízes. A otimização de extração da bergenina assistida por microondas foi realizada com diferentes condições experimentais e planejamento de experimentos. Somente o uso de MeOH como solvente revelou maior capacidade de extração em comparação à mistura EtOH/H2O, as outras condições experimentais não foram significativas. Além disso, a técnica MAE superou as demais em termos de rendimento, obtendo 7,11% de bergenina em MeOH em relação ao extrato bruto, em comparação aos 3,62%, do método clássico oferecendo também a vantagem de reduzir o tempo de extração e economizar o uso de solventes. Quanto a análise dendrocronologia do tronco de P. Dubium constatou-se que nos anéis de crescimento relacionados entre 11º. e 14º.  ano ocorre maior quantidade do composto, com rendimento de 0,198% relação à massa do extrato bruto. Ao desenvolver o polímero impresso molecularmente (MIP), pode ser verificado que a bergenina adsorveu preferencialmente no MIP, quando comparado com aos polímeros não impressos, comprovada pelo maior valor de adsorção em toda a faixa analisada, de 10 a 100 µg/mL, além de extrair 84,54% da bergenina contida na amostra do extrato sugerindo que o MIP pode ser utilizado como base para novos métodos de isolamento da bergenina.

     
22
  • TATIANE DE JESUS SANTOS
  • USE OF GRAVEL FROM DRILLING OIL AND GAS WELLS FOR SUSTAINABLE PRODUCTION OF ZEOLITES APPLIED IN CO2 CAPTURE

     
  • Leader : RAILDO ALVES FIUZA JUNIOR
  • MEMBRES DE LA BANQUE :
  • RAILDO ALVES FIUZA JUNIOR
  • HELOYSA MARTINS CARVALHO ANDRADE
  • LUIZA AMIM MERCANTE
  • ARTUR JOSE SANTOS MASCARENHAS
  • SILVIO ALEXANDRE BEISL VIEIRA DE MELO
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • Data: 25 oct. 2023


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  • Given the environmental problems and risks to human health associated with the generation and disposal of drilling cuttings from oil and gas wells, the development of new alternatives for using this waste is of great importance. In addition to the various studies on the use of gravel for the production of materials for civil construction, an innovative and promising alternative consists of studying gravel as a raw material for the production of value-added aluminous-silice materials, such as zeolites. , which can be used as adsorbents in the chemical industry. Thus, in this study drilling gravel with water-based fluid residue was used and the characterization of this material indicated that it was a heterogeneous residue of clayey nature and compact structure, with SiO2 and Al2O3 contents of 52.91 and 17.95 % respectively, which suggest the possibility of using it as a source of silicon and aluminum. Additionally, it was observed that the silicon oxide present in the residue is mainly in the form of quartz, which indicated the need for a synthesis method with appropriate conditions for solubilizing this highly stable phase. Thus, the synthesis procedure used consisted of three steps: hydrothermal treatment of the gravel in 8M NaOH solution at 240°C for 5h, with the formation of hydroxycancrinite; solubilization of hydroxycancrinite with concentrated HCl under stirring and heating with subsequent addition of the recycled alkaline liquid from the first stage and, finally, hydrothermal treatment at 100°C for 1h, 12h, 1d, 2d, 3d, 5d and 7d. The characterization results of the synthesized materials showed that the hydrothermal treatment time of 2 days, in the last synthesis stage, was the ideal condition for the synthesis of high purity Faujasite-type zeolite X, with high pore area and volume values. Knowing that there is a great environmental concern related to CO2 emissions, the main responsible for global warming, and that zeolite TSA and PSA methodologies. The results obtained indicated that material 2d presented a high CO2 adsorption capacity (9.75 mmol/g at 0°C, 8.05 mmol/g at 25°C, 6.99 mmol/g at 50°C and 3.97 mmol /g at 75°C), performance superior to that reported in the literature for zeolite X synthesized from other residues. Additionally, the synthesized material showed stable adsorption capacity and could be successfully reused for CO2 adsorption at the temperatures and pressures studied.

     
23
  • CARLA LARISSA COSTA MEIRA
  • Synthesis of symmetric carbonylated bistriazoles via CuAAC reaction. Characterization and studies of reactivity, evaluation of their biological properties and potential use as metallic ligands in the electrochemical determination of metals. Studies on methodologies for reducing residual copper content.

     
  • Leader : MAURICIO MORAES VICTOR
  • MEMBRES DE LA BANQUE :
  • MAURICIO MORAES VICTOR
  • VALERIA BELLI RIATTO
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • CAMILLA DJENNE BUARQUE MÜLLER
  • ELIANA MIDORI SUSSUCHI
  • Data: 1 déc. 2023


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  • Click chemistry represents an important strategy within studies in Organic Synthesis. Through its principles, based on Green Chemistry, we develop thermodynamically favorable methodologies, modular and stereospecific reactions, and the formation of stable products. One of the main reactions belonging to this class, and object of study of this work, is the CuAAC reaction - cycloaddition reaction between azide-alkyne catalyzed by copper (I). Through this reaction, it was possible to optimize the experimental parameters, which allowed the synthesis of 16 1,4-disubstituted symmetric carbonylated bistriazoles, with yields ranging from 48 to 97%, 15 of which have not yet been described in the literature, with their structures confirmed by spectroscopic and spectrometric techniques. In these preparations, it was possible to identify the presence of residual copper, at levels of up to ~60,000 ppm, complexed to the synthesized bistriazoles. For this reason, a proposal for an analytical methodology for metal abatement was developed, based on successive extractions with saturated EDTA solution, and sample preparation via digester block and quantification by FAAS, verifying an abatement of up to 97% of the residual copper content (final content ~1800 ppm). In addition to the synthetic aspects, their reactivity and stability were investigated, allowing the obtaining of new derivatives and expansion of proposals for functionalization and versatility of these structures. Complementarily, the new bistriazoles were tested for their fungicidal and antiTrypanosoma cruzi activities. The best result for antifungal activity, against Candida krusei ATCC 20298, was obtained by bistriazole with phenyl substituent, which presented the same MIC as fluconazole® (32 μg.mL-1). In the antiTrypanosoma cruzi evaluation, the tested compounds showed little activity and low levels of selectivity against amastigotes and trypomastigotes of the Tulahuen strain of T. cruzi. Finally, depending on the structural characteristics and substituent chains, five of the new bistriazoles were tested for their capacity as a metallic ligand in the preparation of selective electrodes. Bistriazoles were employed, applying electro-analytical techniques, in the identification of Pb2+, Cd2+, Fe2+ and Cr6+, with results of up to 600% optimization in detection, with detection limits between 10 – 100 µ.mol-1, when compared to standard carbon paste electrode.

     
24
  • TUANY NASCIMENTO DOS SANTOS TRINDADE
  •   SE OF ULTRASONIC WAVES IN THE SYNTHESIS OF Bi2S3-BASED NON-TOXIC NANOMATERIALS AND APPLICATION IN THE PRODUCTION OF SOLAR HYDROGEN

     
  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • LUCIANA ALMEIDA DA SILVA
  • LUIZA AMIM MERCANTE
  • ARTUR JOSE SANTOS MASCARENHAS
  • ELIANA MIDORI SUSSUCHI
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 6 déc. 2023


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  •    Sonochemistry has demonstrated great versatility in intensifying chemical reactions both in the synthesis of nanomaterials and in catalysis. Thus, the present work sought to explore the potential of ultrasonic radiation in the synthesis of semiconductor nanomaterials and application as catalysts in the generation of hydrogen from the division of water molecules (water splitting) through the photocatalytic process assisted by ultrasonic radiation (sonophotocatalysis). The proposal involves the synthesis of nanomaterials based on non-toxic metals, Bi2S3 and ZnS, and BiZnS solid solutions in different molar ratios Bi:Zn:S, to be used in the production of solar hydrogen from an aqueous ethanol solution assisted by sunlight and ultrasonic radiation (sonophotocatalysis). The nanomaterials were synthesized by the sonochemical method with and without thioglycolic acid (ATG), which acts as a complexing agent for metal cations. The materials obtained were characterized using different techniques (XRD, DRS, EDS, TEM and XPS). The results indicate that ATG plays an important role in the morphology of nanomaterials and in the incorporation of zinc into the orthorhombic Bi2S3 matrix. It was possible to verify the formation of solid solutions of the type BiZnS in the presence of ATG in the form of nanorods similar to those of Bi2S3, in addition to nanoparticles ZnS e Zn(OH)2. In contrast, samples prepared without ATG showed low zinc incorporation and no evidence of solid solution formation, resulting in the formation of zinc nanorods. In contrast, samples prepared without ATG showed low zinc incorporation and no evidence of solid solution formation, resulting in the formation of Bi2S3 nanorods and BiOCl nanoparticles. All materials were tested in the hydrogen production reaction from an aqueous ethanol solution after optimizing the reaction parameters such as presence of cocatalyst (platinum), pH, concentration of the sacrificial reagent (ethanol) and type of radiation (artificial sunlight and ultrasound). All samples were active when irradiated with sunlight and ultrasound (sonophotocatalysis), with emphasis on the solid solution obtained from a Bi:Zn:S ratio of 1:4:4 with thioglycolic acid, called BZATG4, which presented a production rate of hydrogen of 33.7 µmol g1 h-1. The best activity of this sample may be related to the presence of the BiZnS/Zn(OH)2 composite, which modifies the absorption profile in the visible region. 

     
25
  • FELIPE ROCHA ARAUJO
  • STUDY OF LaNi1-xFexO3 and LaCo1-xFexO3 PEROVSKITE PRECURSORS ON CH4 DRY REFORMING IN THE PRESENCE OF O2 FOR SYNGAS PRODUCTION 

    Ícone "Verificada pela comunidade"
     
     
     
     
  • Leader : LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MAURICIO BRANDAO DOS SANTOS
  • ROBERT NEWTON DA SILVA HENRIQUES MAGALHÃES
  • ROSANGELA REGIA LIMA VIDAL
  • SORAIA TEIXEIRA BRANDAO
  • Data: 15 déc. 2023


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  • In the present work, perovskites from the LaNi1-xFexO3 (x= 0.0; 0.3; and 1.0) and LaCo1-xFexO3 (x= 0.0; 0.3) series were synthesized, characterized, and evaluated in the dry reforming of CH4 in the presence of O2 (Oxi-CO2). The perovskites were synthesized using the citrate method and characterized through techniques such as TGA, XRD, SEM, TPR-H2, TPSR, and TPO. The diffraction patterns of the samples exhibited characteristic peaks of perovskite phases, indicating the production of highly crystalline materials and suggesting the success of the synthesis method. TPR-H2 profiles demonstrated that the substitution of Ni by Fe hinders the reducibility of species, increasing the temperature of reduction events, along with the formation of an alloy between Fe and Ni. A similar behavior was observed in the substitution of Co by Fe.TPSR analyses indicated that the materials were active for Oxi-CO2, and the general reaction mechanism occurred in two stages: total combustion followed by methane reforming. Catalytic tests showed that the materials exhibited good conversion and selectivity to synthesis gas, obtaining an H2/CO ratio in accordance with the reaction stoichiometry. It was verified that all samples remained stable and active throughout the 20-hour reaction. The sample activation method was effective in obtaining the active phase, as confirmed by XRD results and the observed activity. In the LaFeO3 perovskite, the formation of metallic iron (Fe0) was not observed in TPR and XRD analyses, justifying its low activity, selectivity to synthesis gas, and H2/CO ratio.TPO analyses post-TPSR and post-catalytic tests demonstrated a reduction in carbon deposition when adding Fe to LaNiO3 and LaCoO3 perovskites, indicating that the partial substitution of Ni by Fe or Co by Fe contributed to the formation of more stable catalytic systems resistant to carbon deposition on the catalytic surface during the test period. The chosen reaction conditions, such as temperature and reaction stoichiometry, favored the reduction of coke formation, providing more stability to the catalyst during the reaction. It can be concluded that the analyzed samples were effective and promising in the Oxi-CO2 reaction, with LaNiO3 and LaCoO3 standing out.

2022
Thèses
1
  • SUÉLEM PESSANHA DE SOUZA
  • CALAMITIC LIQUID CRYSTALS BASED ON IMINES: STUDY OF MESOMORPHIC AND STRUCTURAL PROPERTIES

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • THIAGO CAZATI
  • ALOIR ANTONIO MERLO
  • ANDRE ALEXANDRE VIEIRA
  • ELIANE DE OLIVEIRA SILVA
  • LUIZA AMIM MERCANTE
  • SILVIO DO DESTERRO CUNHA
  • Data: 9 févr. 2022


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  • Liquid crystal (LC) is the name given to describe materials that have an intermediary behavior between the three-dimensionally organized solid and the liquid state. Thermotropic LCs are capable of presenting characteristic mesophases, which vary in shape and molecular arrangement, as a function of temperature. The present work investigates the types of mesophases that can be obtained from the variation of alkyl groups in the (E)-4-((phenylimino)methyl)phenyl benzoate system. Eight novel imines were studied to determine the temperature ranges of mesomorphism, thermal stabilities and structural organizations. All intermediates and final products were characterized using the techniques of Melting Point, Infrared Spectrometry, ¹H and ¹³C Nuclear Magnetic Resonance. The thermal properties of the final molecules were studied by differential scanning calorimetry (DSC), polarized light optical microscopy (MOLP) and thermogravimetric analysis (TGA) techniques, revealing that all target compounds had high thermal stability (decomposition temperature) above 280°C) and liquid-crystalline phases characteristic of calamitic LC. The textures observed for the compounds indicate the presence of nematic and smectic C mesophases.

2
  • BRUNA COSTA CERQUEIRA
  • Reactivity of 2-amino-heterocycles against diethyl ethoxy-methylene malonate in the tricomponent synthesis of β-enaminodicarbonyls and telescopic synthesis of pyridopyrimidinones

     
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • RONAN BATISTA
  • SILVIO DO DESTERRO CUNHA
  • TIAGO LIMA DA SILVA
  • Data: 11 févr. 2022


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  •  Synthetic strategies play an important role in the development of sustainable methodologies, aiming to reach important molecules. Thus, the use of multicomponent reactions, one pot and telescopic syntheses, can be applied in this aspect. Diethyl ethoxy-methylene malonate is an important electrophile for the synthesis of polyfunctionalized heterocycles, and can be used in different types of chemical transformations, as well as it is an attractive building block in the synthesis of carbonyl compounds. The present work had as purpose to investigate the reactivity of 2-amino-heterocycles against diethyl ethoxy-methylene malonate, precursors of β-enaminodicarbonyl compounds via a three-component reaction. The β-enaminodicarbonyl compounds were synthesized with yields ranging from 75% to 90%, beginning with 2-aminopyridines derivatives, diethyl malonate and triethyl orthoformate, an unprecedented condition for the synthesis of these molecules. Furthermore, cyclic products were accessed using these reactants under mild conditions, reaching pyrido-pyrimidinone nuclei via telescopic reaction. Hence, the tricomponent and telescopic reactions were more efficient and more environmentally sustainable methodologies being useful to achieve new molecules without the need to synthesize, isolate and purify intermediates.

     
3
  • Rosana Celestino de Jesus
  • ANALYTICAL STRATEGIES FOR DETERMINING THE TOTAL CONTENT OF ESSENTIAL AND POTENTIALLY TOXIC ELEMENTS IN SAMPLES OF PAPRIKE (Capsicum annuum L.) BY ICP OES

     
  • Leader : DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • JACIRA TEIXEIRA CASTRO
  • JOAO BATISTA PEREIRA JUNIOR
  • LAÍS ARAÚJO SOUZA
  • Data: 25 mars 2022


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  • Spices, which in the past were very important in economic terms, are currently widely used by the population for different purposes, considering their wide variety. Paprika (Capsicum annuum L.) is one of these spices, which is added to foods in order to bring them flavor, aroma and their characteristic red color. Being so used in kitchens around the world, it is important to know about its inorganic chemical composition, in order to guarantee the reliability of such a condiment. In this sense, the present work consisted of the use of analytical strategies for the determination of the total content of Ba, Ca, Cu, K, Mg, Mn, Na, P, Sr, V and Zn analytes in samples of sweet, spicy and smoked paprika using the technique inductively coupled plasma optical emission spectrometry (ICP OES). For this purpose, 24 samples (sweet, smoked and spicy) were acquired in commercial establishments in the city of Salvador-Ba and one of them was used in two conditions of sample preparation by wet method (C1: 7 mL HNO3 2 mol L - 1 + 1 mL H2O2 and C2: 7 mL HNO3 4 mol L-1 + 1 mL H2O2) in a closed system digester block.  For both conditions, a mass of approximately 0.25 g, temperature at 180 °C and digestion time of 2 hours were set, respectively. The results obtained indicated a lower value of dissolved organic carbon (DOC) and better visual appearance of the digests for condition 2 compared to condition 1. Thus, condition 2 was chosen for application in the samples. For the evaluation of accuracy, three certified reference materials were used: (CRM Agro C1003a - Tomato leaf, CRM Agro C1005a - Sugar cane leaves and CRM NIST 1547 - Peach leaf) obtaining recovery percentages of 80 at 120%. Addition and recovery tests were also applied and the recovery percentage ranged from 101 to 115%. Precision was evaluated in terms of relative standard deviation (RSD) obtaining values ˂ 10% for the analytes. After applying the validated method in the paprika samples, it was noted that K was the predominant element in them, followed by P, Ca and Mg and that Mn was the microelement with the highest concentration in the samples, followed by Zn, Sr, Cu, Ba and V. For some samples, Mg and Zn were below the LOQ of the proposed method. The concentration ranges obtained, in µg g-1, were: sweet páprica Ca (379 – 4257); K (5675 – 33720); Mg (<607 – 3283);  Na (60 – 727); P (1224 – 3621); Ba (0,67 – 5,48); Cu (2,474 – 7,80); Mn (6,4 – 18,3); Sr (1,02 – 29,3); V(0,11 – 1,114) e Zn (<10,6 – 15,2), For the hot paprika samples: Ca (120 – 9190); K (1953 – 10426); Mg (<607 – 1347);  Na (98 – 16489); P (487 - 2110); Ba (0,66 – 4,96); Cu (1,15 – 5,0); Mn (3,31 – 23,1); Sr (1,3 – 6,2); V(0,029 – 0,46) e Zn (<10,6 – 16,2) and smoked paprika samples Ca (141 – 715); K (1682 – 8271); Mg (<607 – 944);  Na (6712 – 81423); P (456,4 – 5943); Ba (0,64 – 3,29); Cu (1,1 – 3,4); Mn (3,4 – 18,4); Sr (1,31 – 5,91); V (0,023 – 0,4) e Zn (<10,6 – 13,36). The use of multivariate analysis through the application of the PCA and HCA methods did not indicate a general trend of similarity in the groups formed, considering a specific separation only for the types of paprika used in the present study, but a mixture between the varieties (in its majority) in relation to the concentration of the chemical elements determined.

     
4
  • MURILLO HALO QUEIROZ DE OLIVEIRA
  • A computational study of O-H...pi intermolecular interactions in small complexes with water.

  • Leader : ROBERTO RIVELINO DE MELO MORENO
  • MEMBRES DE LA BANQUE :
  • MARIANA ROSSI
  • FERNANDO DE BRITO MOTA
  • GUILHERME AUGUSTO FERREIRA
  • LEONARDO SENA GOMES TEIXEIRA
  • ROBERTO RIVELINO DE MELO MORENO
  • TIAGO VINICIUS ALVES
  • Data: 12 avr. 2022


  • Afficher le Résumé
  • In preparation

5
  • JOSÉ LUIZ CUNHA CORDEIRO
  • PRODUCTION OF SUSTAINABLE CARBONACEOUS STRUCTURES AND THEIR APPLICATION IN THE REMOVAL OF VOLATILE ORGANIC COMPOUNDS (VOCs)

  • Leader : RAILDO ALVES FIUZA JUNIOR
  • MEMBRES DE LA BANQUE :
  • HELOYSA MARTINS CARVALHO ANDRADE
  • JAIME SOARES BOAVENTURA FILHO
  • RAILDO ALVES FIUZA JUNIOR
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • VALERIA CRISTINA FERNANDES
  • Data: 4 mai 2022


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  • Activated carbons were prepared from banana pseudostem and used to capture
    5 different volatile organic compounds (VOCs), which are dichloromethane,
    chloroform, ethyl acetate, hexane and cyclohexane. The biomass was first dried
    in an oven and passed through a process of hydrothermal pyrolysis followed by
    a dry pyrolysis and the activating agents used were KOH or ZnCl2. Activated
    carbons showed high surface areas (701-1312m²/g), and different pore size
    distributions. VOC capture studies were performed in TG and capacity up to
    933mg/g for dichloromethane, 775mg/g for chloroform, 480mg/g for ethyl acetate,
    414mg/g for hexane and 376mg/g for cyclohexane were reached, and these
    values are higher than those presented by some studies in the literature. Higher
    adsorption capacities were related to the amount of available micropores, and
    this capture capacity was enhanced by the amount of small mesopores. As the
    highest adsorbed amounts were obtained for the material activated with ZnCl2 in
    greater proportions and for the dichloromethane molecule, further studies were
    carried out with this adsorbent and this adsorbate. The variation of the adsorption
    isotherm showed that it is an exothermic process and that it is governed by
    physisorption, and this hypothesis was confirmed with the pseudo first order
    kinetic model, and this model was the one that most adjusted to the studies . The
    study in different atmospheres showed that there is a coadsorption phenomenon
    and the relative humidity studies showed that the capture capacity decreases
    slightly at equilibrium. The cycle test proved that the adsorbent can be used in up
    to 10 adsorption/desorption cycles without significantly losing its efficiency.


     
6
  • UESLEY VIEIRA ALVES
  • CHEMICAL STUDY AND EVALUATION OF THE ANTIMALARIAL POTENTIAL OF MARINE SPONGES OCCURRING ON THE COAST OF BAHIA
  • Leader : RONAN BATISTA
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • MAURICIO MORAES VICTOR
  • PAULO ROBERTO RIBEIRO DE JESUS
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • Data: 27 mai 2022


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  • Malaria continues to be a major global health problem. This disease is caused by five Plasmodium species (P. falciparum, P. vivax, P. knowlesi, P. ovale and P. malariae) which are transmitted to people through the bites of infected female Anopheles mosquitoes. Among the Plasmodium species, P. falciparum is responsible for the most severe malaria and causes most of the malaria-related deaths globally. In 2020, 95% of the estimated 241 million cases and 96% of the 627,000 deaths worldwide occurred in sub-Saharan Africa, affecting more severely children under 5 years old. The modest advances in malaria control over the past two decades have stagnated due to the COVID pandemic reducing access to prevention and treatment, as well as the emergence and spread of drug resistance. Thus, novel therapeutic drugs continue to be urgently needed. Taking into consideration the historical contribution of natural products to drug development, our recent study evaluated the in vitro antiplasmodial and cytotoxic effects of 26 extracts from nine marine sponges collected in Salvador, Bahia state, Brazil, and the results revealed that all assayed marine sponges were active against the P. falciparum W2 strain, being Aplysina fulva and Dysidea janieae as the most potent and selective sponges. For this reason, both species were selected for chemical study.

    The first approach was to submit the dichloromethane extract (DCM) obtained previously from A. fulva to preparative TLC fractionation. From the first approach, both aplysterol (1) and a mixture of aplysterol and 24,(28)-didehydroaplysterol (1+2) were isolated from DCM and fully characterized by NMR techniques.

    Taking a different approach, A. fulva was collected again at Porto da Barra’s beach, in Salvador, Bahia, Brazil, following the same cleaning and milling procedure. At this time, however, the material was exhaustively extracted with MeOH, followed by extraction with AcOEt. Then, both extracts were pooled and evaporated, and the residue was suspended in water and partitioned with AcOEt (3x). The AcOEt phases were combined and evaporated completely, and the residue was suspended in MeOH and extracted with hexane (3x). The remaining MeOH phase was concentrated and subjected to a Sephadex column. One of the collected fractions was characterized as a pure compound under TLC analysis, identified as 3,5-dibromoverongiaquinol dimethyl ketal (3). All isolated compounds are potentially antiplasmodial compounds of A. fulva and will be assayed against P. falciparum in due course.

    Finally, D. janieae was collected, cleaned, ground and extracted with MeOH. This extract is going to be dereplicated soon.

7
  • Eunice Cerqueira de Jesus
  • EFFECT OF ESTER AND CINNAMATE GROUPINGS IN THE OBTAINING OF THERMOTROPIC LIQUID CRYSTALS

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ALOIR ANTONIO MERLO
  • ANDRE ALEXANDRE VIEIRA
  • ELIANE DE OLIVEIRA SILVA
  • PATRICIA AKEMI TUZIMOTO
  • PAULO ROBERTO RIBEIRO DE JESUS
  • Data: 27 mai 2022


  • Afficher le Résumé
  • In this work, a homologous series of eight (08) liquid crystals derived from aryloxycinnamates with a wide range of mesomorphism will be presented.

    The molecules investigated in this study were synthesized from the Wittig olefination reaction, carried out by researchers at Quaid-i-Azam University in Pakistan. The characterization was carried out by infrared spectroscopic techniques, 1H and 13C NMR, which demonstrated the effectiveness of the reactions.

    These materials were designed with architecture suitable to exhibit liquid-crystalline properties. In our group, the objective was to study the structure-property relationship of the compounds of the series, and for that, the size of the terminal alkoxy chain was varied between three and twelve carbon atoms, to verify its influence on the mesomorphic properties of the compounds. Mesomorphic properties were investigated by MOLP, DSC, and XRD techniques. All molecules exhibited characteristic textures by MOLP as a result of the organizational defects of the liquid-crystalline phase, being, therefore, possible to prove the birefringence of the analyzed anisotropic materials. The different structural arrangements revealed the type of mesophase present, thus, the nematic phase was confirmed by the Schlieren-type texture and the smectic phase by the focal-conical and fan-shaped textures. The transition temperatures of the mesophases and the energies involved in the processes were determined by DSC, in the second heating and cooling cycle. These experiments confirmed that all compounds in the series exhibited a wide range of mesomorphism between 64 °C and 80 °C.

    The mesomorphism of the samples was shown to be dependent on the length of the alkoxy chain for the organization and stability of the liquid-crystalline phase, where smaller carbon chains exhibited the nematic phase, while larger chains presented exclusively the smectic phase. It was possible to observe that the increase in the chain length resulted in the appearance of more organized phases, as well as reflected in the reduction of melting points and lightening of the compounds. The confirmation of the molecular organization in the mesophase was made through XRD analysis, which showed interference sequences through the Bragg reflection peaks (d001 and d002). The relationship between the diffractions evidences the lamellar packing of the molecules, pointing to the presence of type A smectic mesophase, due to the inexistence of folding, interdigitalization, and inclination of the layers. The decomposition temperatures of the samples were investigated by TGA and the results denoted that all were thermally stable up to 230 ºC. The decomposition values were found to ensure that there is no decomposition of the compounds during heating and obtaining the mesophases.

8
  • INGRID CAROLINE MOTA DE SENA
  • Environmental settings of seagrass meadows control rare earth element distribution and transfer from soil to plant compartments

  • Leader : VANESSA HATJE
  • MEMBRES DE LA BANQUE :
  • LAÍS ARAÚJO SOUZA
  • MARIA ELISABETE MACHADO
  • SERGIO LUIS COSTA FERREIRA
  • TRISTAN CHARLES ROUSSEAU
  • VANESSA HATJE
  • Data: 9 juin 2022


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  • The role of seagrass meadows in the cycling and accumulation of rare earth elements and yttrium (REEY) is unknown. Here, we measured the concentration of REEY in the different compartments of Halodule wrightii (shoots, rhizomes, and roots) and soils in seagrass meadows near sandy beaches, mangroves, and coral reefs in the Todos os Santos Bay, Brazil. We provide data on the accumulation dynamics of REEY in seagrass compartments and demonstrate that plant compartments and soil properties determine accumulation patterns. The ∑REEY in soils were ~ 1.7-fold higher near coral reefs (93.0 ± 5.61 mg kg-1) than near mangrove sites (53.9 ± 31.5 mg kg-1) and were slightly higher than in sandy beaches (81.7 ± 49.1 mg kg-1). The ∑REEY in seagrasses varied between 35.4±28.1 mg kg-1 near coral reefs to 59.2 ± 21.3 mg kg-1 near sandy beaches, respectively. The ∑REE bioaccumulation factor (BAF) was highest in seagrass roots near sandy beaches (BAF = 0.67 ± 0.48). All values of ∑REE translocation are < 1, indicating inefficient translocation of REE from roots to rhizome to shoot. PAAS normalized REE was enriched in light REE (LREE) over heavy REE (HREE) and no fractionation was observed inside seagrasses. The REEY accumulation in Halodule wrightii revealed a low potential of the seagrass to act as a sink for these elements. However, their bioavailability and potential uptake may change with soil properties. Our results serve as a basis for a better understanding of REE biogeochemical cycling and its fate in the marine environment. REE have experienced increased use as they are central to new technologies revealing an urgent need for further investigations of impacts on coastal ecosystems.

9
  • JOEL LEITÃO NASCIMENTO
  • Multistructural rovibrational partition functions truncation and its effects on the thermal rate constants 

  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • LUIZ FERNANDO DE ARAÚJO FERRÃO
  • ANTONIO GUSTAVO SAMPAIO DE OLIVEIRA FILHO
  • MATEUS FERNANDES VENANCIO
  • ROBERTO RIVELINO DE MELO MORENO
  • TIAGO VINICIUS ALVES
  • Data: 13 juil. 2022


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  • Thermal rate constants for the hydrogen abstraction reaction of methyl pentanoate were calculated with the multistructural canonical variational theory state theory with small curvature tunneling. The conformational search was performed with a dual-level approach, and the multistructural torsional anharmonicity effects were corrected through the rovibrational partition function calculated with the multistructural method based on a coupled torsional potential (MS-T(C)). At the MPWB1K/6-31+G(d,p) level of theory, 23 conformers of methyl pentanoate were found in the conformational search. The transition states of R1-R5 ranged from 27 to 64 structures. A systematic analysis of the truncation of the rovibrational partition functions and their effects on thermal rate constants was carried out. Our results indicate that the truncation of the partition functions in a small set of conformations generates deviations in the rate coefficients ranging from 20 to 60%, compared to estimates of the rate coefficients with the consideration of all the structures of reagents and transition states. The reliability and perspective of the present results are expected to motivate and guide future investigations on reactions involving long-chain methyl esters with low computational costs.

10
  • ALLANA SOBRINHO DOS SANTOS
  • DEVELOPMENT OF DECOMPOSITION PROCEDURES IN CLOSED SYSTEMS FOR WHITE CHEESE ELEMENTAL ANALYSIS

     
  • Leader : RODOLFO DE MELO MAGALHAES SANTANA
  • MEMBRES DE LA BANQUE :
  • RODOLFO DE MELO MAGALHAES SANTANA
  • MARIA DAS GRACAS ANDRADE KORN
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • KELLY DAS GRAÇAS FERNANDES DANTAS
  • Data: 13 déc. 2022


  • Afficher le Résumé
  • Cheese is the most consumed dairy product, its popularity is attributed to its taste, versatility of use, price, variety, and nutritional value. Recently, consumers have preferred white cheeses to yellow cheeses due to their low caloric content; however, studies on determining essential or potentially toxic elements are still scarce. Thus, the present work aims to evaluate decomposition procedures in closed systems with different forms of heating for elemental analysis in samples of white cheese by ICP OES. The optimization step was carried out using a two-level complete factorial design with an experimental domain for temperature between 140 and 180 ºC for both methods; and concentration of HNO3 2, 8, and 14 mol L-1 at 40, 60, and 80 min and 2, 6 and 8 mol L-1 for 20, 25 and 30 minutes, in closed digester block and microwave cavity, respectively. The dissolved organic carbon (DOC) content evaluated the decomposition efficiency. For both methods, the concentration parameter was significant (p≤0.05) with a negative effect and temperature for the microwave irradiation method. Additionally, the interaction between the abovementioned factors was significant for decomposition in the digester block. Thus, the decomposition conditions established by multivariate optimization were 180 ºC for 80 min and 140 ºC for 30 min, in a digester block and microwave, respectively, using 6 mL of 2 mol L-1 HNO3 and 2 mL of H2O2 30% (v v-1). The determined residual acidity was 0.76±0.0.04 mol L-1 with conductive heating and 0.40±0.03 mol L-1 by microwave irradiation. The proposed methods showed good precision (RSD <10%) with a wide working range, good linearity (R≥0.999), and detection and quantification limits below 0.18 and 0.61 mg L-1, respectively. The accuracy of both methods was confirmed by comparison with the reference method, with no occurrence of significant systematic errors (p>0.05). The developed decomposition procedures were applied to analyze white cheeses of the buffalo mozzarella, minas frescal, and ricotta types. The values found were compared with those indicated on each label, and each nutrient's contribution in its respective IDR was calculated.

     
Thèses
1
  • BÁRBARA ELIZABETH ALVES DE MAGALHÃES

  • ANALYTICAL STRATEGIES FOR DETERMINING THE CONTENT OF PHENOLIC BIOACTIVES IN WHOLE FLOUR AND THEIR POTENTIAL ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES

  • Leader : WALTER NEI LOPES DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • LETÍCIA MALTA COSTA
  • MARCOS DE ALMEIDA BEZERRA
  • SERGIO LUIS COSTA FERREIRA
  • WALTER NEI LOPES DOS SANTOS
  • Data: 27 janv. 2022


  • Afficher le Résumé
  • Plant foods are potential sources of bioactive compounds, such as phenolic compounds, which are natural antioxidants, and their consumption may prevent oxidative damage that leads to the development of several diseases. In view of the large consumption of wholemeal flours and the health benefits associated with their intake, the study of the composition and biological activities of these foods is relevant. In this sense, the phytochemical composition, the content of phenolic bioactives and the antioxidant potential of flaxseed (brown and yellow), sesame (black and white), chia (black and white), quinoa (white) and amaranth (white) wholemeal flours. Therefore, the phenolic compounds extraction method was optimized through experimental designs, using methanol and acetone (8:2, v v-1 ) for solid-liquid extraction. The phytochemical profile of the extracts was analyzed by TLC, the in vitro antioxidant capacity and the total phenolic compounds contents of the extracts were determined by spectrophotometric methods. An HPLC-DAD chromatographic method was developed for the determination of 18 bioactive compounds and multivariate analyzes were applied to the chromatographic profile of the extracts to identify the potential phytochemical biomarkers of wholemeal flours. The bioaccessibility of phenolic compounds and antioxidants from whole white quinoa flour was evaluated after in vitro digestion simulation. The antibacterial activity of chia and quinoa flours was evaluated by serial microdilution and agar diffusion. The results indicated that the wholemeal flours analyzed have a wide variety of secondary metabolites (phenolic compounds, anthocyanins, lignans, tannins, anthracene derivatives, anthraquinones, naphthoquinones, xanthines, coumarins, saponins, terpenes and steroids) with different biological properties and potential applicabilities. The phenolic profile and the antioxidant activity varied significantly among the analyzed samples, of which the chia flour samples showed higher total contents of phenolic compounds (4.10–5.89 mgEAG g -1 flour) and flavonoids (2.78–5.45 mgEQ g -1 flour), high antioxidant capacity (82–94% of DPPH• inhibition) and bacteriostatic activity against Bacillus subtilis and Pseudomonas aeruginosa at MIC of 2000 μg mL-1 . The chromatographic method developed is applicable to different matrices that contain the bioactive compounds: catechin, rutin, naringenin, quercetin, kaempferol, chrysin, vanillin, theobromine and gallic, protocatechuic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, synapic, ellagic and transcinnamic acids. Higher concentrations of sinapic acid (7.15 to 28.63 μg g-1 ) and rutin (13.04 to 52.83 μg g-1 ) in quinoa flours, catechin (30.95 to 263.71 μg g-1 ) and trans-cinnamic acid (19.64 to 238.56 μg g-1 ) in chia flours, chlorogenic acids (1.96 to 8.82 μg g-1 ) and p-coumaric (1.08 to 14.23 μg g-1 ) in flaxseed flour, and chlorogenic acid (2.97 to 56.34 μg g-1 ) and protocatechuic acid (12.87 to 47.02 μg g-1 ) in sesame flour were determined. In the evaluation of bioaccessibility, it was observed that most of the phenolic compounds and antioxidants in quinoa flour become bioaccessible mainly during and after gastric digestion. Multivariate analyzes showed that the phenolic profile depends on the species and variety of the plant, making it possible to identify potential biomarkers of the analyzed wholemeal flours.

2
  • LUANA BASTOS SANTOS
  •  

    Green solvents and digital imaging colorimetry: new approaches in liquid-fases microextration for elemental determination
     
  • Leader : VALFREDO AZEVEDO LEMOS
  • MEMBRES DE LA BANQUE :
  • MARCOS DE ALMEIDA BEZERRA
  • WALTER NEI LOPES DOS SANTOS
  • VALFREDO AZEVEDO LEMOS
  • ALEXILDA OLIVEIRA DE SOUZA
  • RICARDO ERTHAL SANTELLI
  • Data: 10 févr. 2022


  • Afficher le Résumé
  •  

     In recent years, the search for the principles of green chemistry in analytical methods has grown considerably. In green analytical chemistry, solvents occupy an essential place. To be qualified as a green medium, a solven needs to meet different criteria, such as availability, low toxicity, biodegradability, and low cost. Ionic liquids, eutectic solvents and switchable hydrophobicity solvents fall into this new class. In this work, a liquid-fase microextratcion system was developed usind each of the three types of green solvents metioned above. The model elements were antimony, cobalt and vanadium. The strategies presented several advantages, such as low cost, waste generation, low risk to the operator, and high enrichement factor, among others. The system were applied to the determination of the model elements in food and environmental water samples.
3
  • LARISSA DE SÃO BERNARDO DE CARVALHO
  • EVALUATION OF STRATEGIES FOR DETERMINING INORGANIC CONSTITUENTS IN INSTANT SOUPS BY PLASMA EMISSION SPECTROMETRY

     
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MARIA DAS GRACAS ANDRADE KORN
  • VALFREDO AZEVEDO LEMOS
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • CLEBER GALVAO NOVAES
  • AMALIA GEIZA GAMA PESSOA
  • Data: 4 mars 2022


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  • This work describes the evaluation of strategies for inorganic chemical determination by microwave-induced plasma optical emission spectrometry (MIP OES) and inductively coupled plasma optical emission spectrometry (ICP OES) in instant soups. In the first study, the MIP OES with N2 plasma was evaluated for the determination of Cu, K, Mg, Mn, P and Zn in soups, after acid decomposition assisted by microwave radiation. The sample preparation procedure consisted of using a dilute nitric acid solution, 2 mol L-1, and hydrogen peroxide. The accuracy of the method was evaluated by analyzing three certified reference materials: NIST 1515 (apple leaves), NIST 1568b (rice flour) and NIST 3234 (soy flour) and recoveries ranged from 83.3 to 107.5%. Addition and recovery tests were also carried out and the recoveries obtained ranged from 86.0 to 106.0%. The estimated detection limits for Cu, K, Mg, Mn, P and Zn were 0.09, 4.90, 1.00, 0.04, 5.40 and 0.88 mg kg-1, respectively. The use of N2 microwave-induced plasma proved to be a low-cost alternative for routine analysis. In another study, several strategies for the development and applicability of an extraction procedure for the determination of Ca, Cu, Fe, K, Mg, Mn, P, Sr and Zn in instant soups by ICP OES were evaluated. The investigated strategies were: use of an acid extracting solution (hydrochloric acid 8% (v v-1) and alkaline (tetramethylammonium hydroxide (TMAH, 25% (m v-1), cryogenic grinding of samples and use of internal standardization techniques (IS ) and standard addition (SA) compared to external calibration (EC). The instrumental plasma parameters were also optimized. The results were evaluated by the extraction efficiencies (%) of the analytes, which were below 80% for some analytes, possibly due to the different compositions of the soup samples. Therefore, further studies should be developed in order to propose a unique extraction procedure for this type of sample.

     
4
  • TAMARA VIEIRA REIS
  • Secondary metabolites of the ethyl acetate extract of the roots of Kielmeyera reticulata
  • Leader : ELISANGELA FABIANA BOFFO
  • MEMBRES DE LA BANQUE :
  • ELISANGELA FABIANA BOFFO
  • PAULO ROBERTO RIBEIRO DE JESUS
  • VLADIMIR CONSTANTINO GOMES HELENO
  • WALMIR SILVA GARCEZ
  • LOURDES CARDOSO DE SOUZA NETA
  • Data: 20 mai 2022


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  • This study describes the isolation and structural identification of secondary metabolites present on the extract in ethyl acetate obtained from the roots of the Kielmeyera reticulata Mart. (Calophyllaceae) species, collected in the sandbanks of the Parque Metropolitano do Abaeté, Salvador-Bahia. Species in this family are primarily known as sources of xanthones, which are considered their chemosystematics markers. The roots were subjected to extraction with ethyl acetate. The fractionation of the extract was carried out by vacuum flash silica column chromatography, dry packed, with the solid sample inserted, using hexane and dichloromethane in increasing order of polarity as eluent system, and the compounds were isolated by preparative chromatography on silica gel using hexane and ethyl ether as an eluting system. Compound identification was performed using spectroscopic methods such as one-dimensional (1H and 13C) and two-dimensional Nuclear Magnetic Resonance (gHMBC and gHSQC). The following compounds were isolated and identified from the extract: three phloroglucinol derivatives, three biphenyls, one 4-alkylcoumarin, one xanthone and the steroids β-sitosterol and stigmasterol. Three new substances were isolated and identified: a prenylated derivative of phloroglucinol and two biphenyls.

5
  • Verônica Maria Bastos Maciel Bispo

  • FUNGAL CELL FUNCTIONALIZATION WITH NANOPARTICLES METALLIC FOR THE DEVELOPMENT OF HIGH AREA ELECTRODES SURFACE AND ACTIVE SUBSTRATES TO RAMAN SPREADING SURFACE INTENSIFIED

  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • GIUSEPPE ABÍOLA CÂMARA DA SILVA
  • ANDRE ROSA MARTINS
  • GUILHERME AUGUSTO FERREIRA
  • LUIZA AMIM MERCANTE
  • MARCOS MALTA DOS SANTOS
  • REGINA MARIA GERIS DOS SANTOS
  • Data: 27 mai 2022


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  • Gold and platinum metallic microtubes were synthesized by cultivating filamentous fungal species on gold and platinum nanoparticles stabilized by the citrate ion. In this strategy, metallic nanoparticles are deposited by the process of self-assembly on the cell wall of fungal cells of filamentous fungal species (Phialomyces macrosporus, Aspergillus niger, Aspergillus brasiliensis and Talaromyces pinophilus), resulting in the synthesis of biomimetic microstructures. The metallic microtubes were obtained by removing the biological mold through a heat treatment process. The fungal/metal nanoparticles systems were analyzed using pH, Zeta potential, Dynamic Light Scattering (DLS) and Ultraviolet and Visible Absorption Spectroscopy with the aim of understanding the stability of gold nanoparticles against primary and secondary effects produced by fungi, as well as the effect of citrate ion depletion in the system. The biohybrids and metallic microtubes obtained were characterized through the techniques of energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). The joint analysis of these techniques confirmed the formation of gold and platinum microtubular structures, as well as allowed to elucidate of the microstructural details of the gold microtubes. As explained the amount of metallic nanoparticles assimilated in the cell wall of each fungal species used, specifically, the TGA results showed that the fungal species Talaromyces pinophilus and Phialomyces macrosporus assimilate, respectively, 36% and 40% of gold nanoparticles in the cell wall. The central scope of the present doctoral work was to apply gold biomimetic microtubes. Then, the cyclic voltammetry measurements showed that the surface area of the modified microstructured gold electrode obtained from the fungal cell mimic is 31 times greater than the area of the polished gold electrode. While the Raman Spectroscopy measurements using plasmonic microtubes as substrate allowed the identification of a trace concentration of Rhodamine B at a concentration of 10-8 mol.L1 , evidencing the effect of surface scattering enhancement (SERS) of said plasmonic microtubes. Finally, the SEM, MET and EDS analyzes showed the synthesis of biohybrids consisting of filamentous fungi and platinum nanoparticles. Furthermore, the formation of unique microtubes of platinum oxide was observed.

6
  • Arlene Santos Silva
  • ANALYTICAL STRATEGIES FOR DETERMINATION OF METALS IN TOOTHPASTE SAMPLES

     
  • Leader : ANA MARIA PINTO DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • MARIA ELISABETE MACHADO
  • ANA MARIA PINTO DOS SANTOS
  • GEOVANI CARDOSO BRANDÃO
  • JORGE LUIS OLIVEIRA SANTOS
  • Data: 28 juin 2022


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  • The daily use of supporting products in oral hygiene inspired a study of the metal content in its content. In the present work, methods for the determination of metals in toothpaste samples were developed. The study is divided into three parts. In the first part of work, a method for determination of Cd and sequential simultaneous determination of Ni and Fe using suspension sampling was developed. The work aimed to reduce analysis time and waste generation. Method optimization performed using chemometric tools. The determination of metals was performed by high resolution continuous source atomic absorption spectroscopy with electrothermal atomization (HR-CS ET AAS). In the second part of work, an exploratory analysis of toothpaste samples obtained in Brazil and Spain carried out. The analysis aimed to identify the presence and contents of potentially toxic metals in the samples. In this study, principal component analysis (PCA) and hierarchical component analysis (HCA) were used to discriminate the samples. The metal contents were determined using inductively coupled plasma optical emission spectroscopy (ICP OES) and inductively coupled plasma mass spectroscopy (ICP-MS). The third part of work carried out aims at the determination of aluminum in toothpaste samples using ICP-MS and atomic absorption spectroscopy with electrothermal atomization (ET AAS). Given the toxic potential of excess aluminum in the human body. 

     
     
7
  • Bruna Rosa da Silva Santos
  • EVALUATION OF THE CHEMICAL AND NUTRITIONAL COMPOSITION OF CASSAVA LEAF AND PRESERVED OLIVES USING SPECTROANALYTICAL AND CHEMIMETRIC TECHNIQUES
     
     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • JOAO BATISTA PEREIRA JUNIOR
  • MARCOS DE ALMEIDA BEZERRA
  • GUSTAVO GALO MARCHEAFAVE
  • WALTER NEI LOPES DOS SANTOS
  • DANNUZA DIAS CAVALCANTE
  • Data: 16 août 2022


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  • In chapter I, studied the cassava leaf grown in the State of Bahia, Brazil, after undergoing thermal and fermentation processes in order to eliminate the hydrocyanic acid present in its structure. In this sense, the physicochemical characteristics and the proximate composition were evaluated by means of the methods described by the Adolfo Lutz Institute. The determination of the mineral composition took place through the use of the microwave-assisted acid decomposition procedure, followed by the measurement of the analytical signal through the ICP OES. The accuracy of the method was confirmed by analysis of certified reference materials from spinach and apple leaves (NIST 1570a and NIST 1515) from the Institute of Standards and Technology (NIST). The residual carbon content was evaluated using the ICP OES. When comparing raw samples with fermented and cooked samples, nutrient losses can be observed. The results were evaluated by means of multivariate analysis (PCA and HCA), in which it was observed a tendency for the samples to be separated into groups, according to the type of treatment to which the samples were submitted. For the bioactive substances and antinutrients, the optimization of the extraction method was used as an initial step, using the following designs: Centroid-Simplex Mixture, Full Factorial and Doehlert. The results presented showed that there were losses of analytes by leaching when comparing the raw samples with those that underwent some type of processing. In Chapter II, bioactive substances and antinutrients were evaluated in samples of preserved olives collected in different markets in the city of Salvador, Bahia, Brazil. This fruit to be consumed underwent chemical processes in order to reduce the content of oleuropein responsible for the bitter taste of olives in natura. Thus, the extraction method of bioactive substances and antinutrients was optimized by applying chemometric tools. From the results of the optimal conditions, we have; stirring time 7 minutes; acidified methanol 0.05 molL-1 and water bath temperature 62ºC. The total phenolics, total flavonoids, tannins and sodium oxalate were also determined, and it was possible to observe that when comparing the different stages of fruit maturation, black olives had a higher content than green olives.

     
     
8
  • SAMIR HIPOLITO DOS SANTOS
  • Inorganic constituents present in samples of urban soil, fertilizers and food: development of methodologies, use of chemometric tools and evaluation of guide values

  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • JOAO BATISTA PEREIRA JUNIOR
  • ELISANGELA DE ANDRADE PASSOS
  • MADSON DE GODOI PEREIRA
  • MARCO TADEU GRASSI
  • SARAH ADRIANA ROCHA SOARES
  • SILVÂNIO SILVÉRIO LOPES DA COSTA
  • CARLOS ALEXANDRE BORGES GARCIA
  • TATIANE DE ANDRADE MARANHÃO
  • ADNÍVIA SANTOS COSTA MONTEIRO
  • Data: 22 août 2022


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  • In this work, three methods of sample preparation were developed using closed digester block and ultrasound-assisted digestion methods, being one procedure for urban soil samples, and two procedures for food essence. Chemical analyzes were performed using inductively coupled plasma optical emission spectrometry (ICP OES). The soil sample preparation procedure was optimized using fractional factorial design and Doehlert design. The accuracy of the analytical method was confirmed by chemical analysis of six certified reference materials: , light sandy soil (BCR 142), moroccan phosphate rock  (BCR 032), phosphate rock (Florida, NIST SRM 120c), phosphate rock, (Western, NIST SRM 694), trace elements in multi-nutrient fertilizer (NIST SRM 695) and Montana I Soil highly elevated trace element concentrations (NIST SRM 2710a), obtaining agreement values between 80 and 119%. Precision was expressed as relative standard deviation (%RSD), being better than 10%, (n=3). The proposed methodology was applied to 43 samples of urban soils collected from the municipality of Aracaju, Sergipe, Brasil, in two depth fractions (fraction S (0-20 cm) and F (20-40 cm)). In these samples, the concentrations of 22 inorganic constituents (Al, As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, U , V and Zn) were determine by ICP OES. According to the soil quality reference values (valores de referência de qualidade para solos - VRQs), only the 2S and 2F samples showed lower concentrations of inorganic constituents than the VRQs, and in samples 13F, 15S and 18F values were found higher than the prevention value. (VP, 2.00 mg kg-1, Sb). The granulometric analysis showed that the chemical elements are distributed among the very fine sand, silt and clay particles. The enrichment factor (EF) indicated that only samples 11S, 12S and 12F showed severe enrichment by anthropic influences for Zn concentrations. The geoaccumulation index (Igeo) characterized sample 11S as moderately polluted and samples 12S and 12F as moderately to heavily polluted. Principal component analysis (PCA) indicated that in samples from areas where vehicular traffic was more intense, the concentrations of chemical elements were higher. The methodology proposed for soil samples was also applied to mineral fertilizer samples for determination of the same 22 inorganic constituents by ICP OES. The concentrations of chemical elements varied between 0.16 mg kg-1 (Cd) and 427 g kg-1 (P). Fertilizer samples Fert.12, 14, 15, 16 and 18 showed the highest concentrations in most of the chemical elements determined. The following samples showed concentrations above the maximum limit allowed by current Brazilian legislation: Fert.12, Fert.14, Fert.15, Fert.16 and Fert.18 for As, Fert.12, Fert.14 and Fert.15 for Cd and Fert.12 for Cr and Pb. The PCA indicated that the samples with the highest concentrations of the chemical elements are of the superphosphated type. Two procedures for preparing the food essence samples were optimized. The first one, involving a fractional factorial design that allowed a digestion assisted by an ultrasonic bath, with the chosen factors such as: HNO3 concentration, ultrasonic bath time, heating temperature, for a volume of 2.0 mL of sample. Another preparation method using a closed digester block was also optimized, through fractional factorial design containing the following factors: HNO3 concentration, digestion time, heating temperature for a volume of 2.0 mL of sample. The accuracy of the ultrasound-assisted digestion method was evaluated by comparing it with the digestion block method, varying between 90% (Mn) and 117% (Fe). The accuracy of the two methods was also evaluated through the analyte addition and recovery test, ranging from 84% (Al) to 104% (Ca) for ultrasound-assisted digestion, and for digestion in a closed digester block, ranging from 80% ( Mg) and 119% (Sr). Precision for both sample preparation methods was expressed as a relative standard deviation, being better than 10%, (n=3). The methodology using ultrasound-assisted digestion was applied to samples of food essence, energy drink, powdered gelatin and powdered soft drink, for determination of Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V and Zn by ICP OES. The elements Na (158 mg L-1) and S (594 mg L-1) presented the highest average concentrations in the food essence samples. The presence of Al was found only in samples of energy drink A (2.52 mg L-1) and powdered soft drink (7.50 µg g-1). The sample of energy drink A was the only sample that showed a concentration of Ba (0.119 µg g-1). Only the powdered refreshment sample showed a concentration of Ti

9
  • CLAUDIO TARANTO LIMA BRAGA
  •   EFFECT OF THE PREPARATION METHOD ON THE PROPERTIES OF CERIA ANODE CATALYST FOR SOFCS

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • RAILDO ALVES FIUZA JUNIOR
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • ZENIS NOVAIS DA ROCHA
  • CARLOS AUGUSTO DE MORAES PIRES
  • ALEXILDA OLIVEIRA DE SOUZA
  • Data: 9 sept. 2022


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  •  

    Considering the current need for energy in all aspects of modern life, it becomes essential to meet the growing demands within a perspective of sustainability of the planet. Fossil sources used for energy supply cause severe impacts environmental issues, making the search for renewable energy sources urgent, as well as the generation energy efficient. Among the technologies proposed to overcome these difficulties, cells solid oxide fuel (SOFCS) are recognized as the most suitable for the large-scale clean energy production, especially in remote places. Those devices are versatile and have the advantage of using different fuels, including biogas, a renewable fuel, consisting of methane and carbon dioxide. this mixture gas can be fed directly from the anode of the SOFC, over a suitable catalyst and produce hydrogen and synthesis gas, reagents of the electrochemical reaction, which will produce electricity. In this work, nickel catalysts (10% m/m) supported on cerium oxide doped, or not, with gadolinium (10% m/m), prepared by different methods, with a view to obtaining catalysts for dry reforming (reaction between methane and carbon dioxide carbon), directly on the SOFC anode. The sol-gel methods were used, from combustion and Marcilly to obtain the supports that were impregnated with solutions of nickel nitrate (10% m). The supports and catalysts were characterized by ray diffraction. X, temperature programmed reduction, Raman spectroscopy, UV-Visible spectroscopy, Fourier transform infrared spectroscopy, temperature desorption programmed with ammonia and transmission electron microscopy. The formation of the cubic phase of cerium oxide, in all samples, regardless of the method of preparation and the presence of gadolinium. The presence of nickel oxide was identified, but the gadolinium formed a solid solution with cerium oxide. In the network of this oxide, gadolinium induced the formation of oxygen vacancies, increasing the mobility of ions in the solid and facilitating the reduction process. This effect was more pronounced in samples prepared by Marcilly's methods and combustion.  The preparation method decreased the interaction of nickel with support in the order combustion<Marcilly<sol-gel, making it difficult to reduce nickel, regardless of the presence of gadolinium. In all cases, only the formation of weak and moderate acid sites, related to the presence of structural defects, that favor the storage of oxygen with a high capacity of donating electrons. The method de Marcilly led to the formation of weaker acidic sites, in relation to the materials obtained by the other methods. The average particle sizes of the catalysts were dependent on of the method of preparation in the order Marcilly<combustion<<sol-gel. Considering the properties generated in the solids, as a result of the different methods, the catalyst containing gadolinium and prepared by the Marcilly method is the most promising to lead to dry reforming on the anode of a SOFC. It has the lowest nitrate content, the particles smaller and the lowest acidity, which are suitable properties for this application.

     

10
  • CAMILA CARVALHO DE OLIVEIRA SANTOS
  • NINA synthesis: a new strategy for large-scale production of gold nanorods using the silver-assisted seed-mediated method

     
  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • MARCOS MALTA DOS SANTOS
  • LUIZA AMIM MERCANTE
  • GUILHERME AUGUSTO FERREIRA
  • MADSON DE GODOI PEREIRA
  • ANTONIO FERREIRA DA SILVA
  • Data: 19 sept. 2022


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  • The present work aims to obtain quality and uniform gold nanorods (AuNBs) from the same synthesis, so that amount of material is sufficient to advance in several stages of application research, which is still a current challenge. The importance of AuNBs is significant due to their optical, catalytic, photothermal, SERS and other properties. In order to provide a solution to this question, in the present thesis, a strategy for the production of gold nanorods via large-scale silver-assisted seed-mediated synthesis was considered, as well as the characterization of the surface of Au-NBs via XPS to contribute to the understanding of the role of chemical species on the surface of these nanoparticles. The large-scale synthesis, named NINA, was carried out in five steps, i-Production of large amount of the growth solution; ii-fractionation of the growth solution into parts and 10ml; iii- seed preparation; iv- introduction of the seed in the portions; v- junction of Au-NBs portions. The material was characterized using the techniques of transmission electron microscopy (TEM), electron spectroscopy in the ultraviolet and visible region (UV-Vis), X-ray photoelectron spectroscopy (XPS). As main results, the production of gold nanorods in quantities of 1 liter stands out. In which the portions that make up the AuNBs solution have greater spectral similarity, UV-Vis, evaluated based on the maximum of the longitudinal peak and width at half height of this peak (fwhm), than the replicas of the original synthesis by Nikoobakht and El Sayed ( 2003), indicating the viability of NINA synthesis. There is a projected production of at least 8 liters from this synthesis method. From the XPS data, a better understanding of the chemical state of the silver species, bromide and CTA+ ions present on the surface of Au-NBs was obtained, highlighting that silver was found in two oxidation states Ag(0) and Ag( I).

     
11
  • EDSON EVANGELISTA SILVA
  • SYNTHESIS OF AZA-POLY-HETEROCYCLES THROUGH THE AZA-ANNELATION [3+3] OF 2,5-DIAMINO-1,4-BENZOQUINONE AGAINST DIFFERENT POLYCARBONYLATED ELECTROPHILS
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • ANDRE ALEXANDRE VIEIRA
  • JORGE MAURICIO DAVID
  • MAURICIO MORAES VICTOR
  • RONAN BATISTA
  • SABRINA TEIXEIRA MARTINEZ
  • FERNANDO DE CARVALHO DA SILVA
  • SANDRO JOSE GREGO
  • DAVID RODRIGUES DA ROCHA
  • Data: 11 oct. 2022


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  • In this work, the study of the reactivity of 2,5-diamino-1,4-benzoquinone against arylidenes derived from Meldrum acid, barbituric acid and 1,3-indandione in aza-ringing- [3+3] reactions was carried out for the first time, 06 new quinolinetrionic nuclei were obtained in yields between 20 and 93%, in addition to 04 new quinolinetetraonic nuclei in yields between 52 and 98%. Additionally, from the synthetic application of the 6-amino-4-phenyl-quinolinetrione obtained, it was possible to access a new benzoxazole-dihydroquinoline hybrid via oxidative cyclization reactions, promoted by Pd/C (20 mol%). In addition, the reactivity of 2,5-diamino-1,4-benzoquinone against ninhydrin was also investigated and it was possible to obtain an unprecedented pentacycle compound, with a yield of 92%. In addition, a study for the application of 5-amino-isatin in obtaining quinolinic nuclei, generated two new hybrids between isatin/quinoline with 43% and isatin/naphthoquinone with 65% yield.

12
  • RODRIGO DA SILVA FRANCO
  • APPLICATION OF CHEMOMETRIC TOOLS IN THE STUDY OF Pd ELECTRODEPOSITION PROCESS IN THE PRESENCE AND ABSENCE OF ULTRASOUND ON MODIFIED DIFFUSION LAYERS

  • Leader : VALERIA CRISTINA FERNANDES
  • MEMBRES DE LA BANQUE :
  • Francisco Trivinho Strixino
  • GABRIEL CHRISTIANO DA SILVA
  • GIANCARLO RICHARD SALAZAR BANDA
  • RAILDO ALVES FIUZA JUNIOR
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • SILVANA MATTEDI E SILVA
  • Vinicius Del Colle
  • Data: 3 nov. 2022


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  • One of the main challenges in the preparation of gas diffusion electrodes is related with the high cost of platinum that is the main component of the catalytic layer. In this context, palladium is an interesting candidate to substitute platinum, partially or completely, due to its lower cost, higher abundance and good catalytic activity on reactions using hydrogen. In this study, the electrodeposition of palladium was investigated by using electrochemical techniques assisted by ultrasound. The electrochemical deposition was studied by using a factorial design 24-1 as a chemometric tool, aiming to reduce the number of experiments and estimate the effects of interactions between the variables. The investigated variables were the number of deposition cycle (NDC = 100 and 300 cycles); scan rate (SR = 50 and 100 mV s-1); Pd2+ concentration ([Pd2+] = 0.5 and 1.0.10-3 mol L-1) and in the absence or presence of ultrasound waves (US, 100 W). The electrochemically active surface area (ECSA) was used as response. According with the study every variables were significant, the US, NDC, SR and the [Pd2+], with the US presenting more significance. Some second and third order interactions were also significant. The best condition evaluated was that performed with higher NDC, [Pd²+], in lower SR and in the presence of ultrasound. Through the application of the ANOVA-PCA technique, it was possible to observe that all variables contribute to a change in the profile of the observed voltammetric responses, especially in the peak related to the hydrogen desorption process. Morphological and structural analyzes by scanning electron microscopy (SEM), scanning electron microscopy by field emission generated by an electron gun (FEG), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) were performed. In general, it was possible to verify that the use of ultrasound during the Pd electrodeposition process promoted an increase in the amount of electrodeposited Pd, affecting the morphology of the agglomerated nanoparticles, which seem to promote an increase in ECSA

13
  • Eileen Rocio Niño Zambrano

  • ORIGIN AND ACCUMULATION OF POLYCYCLIC AROMATIC COMPOUNDS IN SEDIMENTS FROM BAÍA DEADOS SANTOS

     
  • Leader : GISELE OLIMPIO DA ROCHA
  • MEMBRES DE LA BANQUE :
  • GISELE OLIMPIO DA ROCHA
  • MARIA ELISABETE MACHADO
  • PEDRO AFONSO DE PAULA PEREIRA
  • VANIA PALMEIRA CAMPOS
  • JULIANA LEONEL
  • RENATO DA SILVA CARREIRA
  • Data: 14 déc. 2022


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  • The vertical distribution of pollutants in marine sediments preserves and acts as a reservoir of quantitative data on anthropogenic emissions that have occurred. Polycyclic aromatic compounds (PAC) include conventional polycyclic aromatic hydrocarbons (HPA), in addition to their nitrated (NHPA), oxygenated (OHPA) and heterocyclic polycyclic aromatic sulfur (PASH) derivatives, considered unconventional are ubiquitous in the environment, many of them have toxic, mutagenic and carcinogenic properties. Studies of unconventional PAC in sediments in Todos os Santos Bay (TSB) are scarce, although several of them have shown greater toxicity than their HPA precursors. In addition, there is no complete study on the temporal distribution of anthropogenic impacts from PACs sedimentary records in the TSB. The TSB is of significant interest due to its socioeconomic and cultural importance to Brazil. This thesis evaluates the occurrence and possible origins of PAH, NPAH, OPAH and PASH in a temporal historical context in four sediment cores from the northern region of the Baía de Todos os Santos (Brazil). This work aimed to evaluate the vertical distribution of anthropogenic impacts through the concentration of PAH, NPAH, OPAH and PASH and their possible origins in a temporal historical context in four sediment cores collected in the north, northeast and west regions of the BTS. In total, 51 compounds were extracted using a microscale solid-liquid extraction procedure and the determination of these compounds was performed using gas chromatography-mass spectrometry (GC-MS). The method was validated and applied to cores collected near the mouth of the Paraguaçu River, the Port of TEMADRE, the Port of Aratu and the RLAM refinery. From the results, it was possible to verify quantitative changes of the chemical groups analyzed in the cores over time and to relate them to the anthropic activities developed in the region. The highest total concentration of PAH and PASH were for the core collected near to Port of Aratu, in turn, NHPA were higher in the core collected at mouth of the Paraguaçu River and OHPA were more abundant in the core collected of RLAM refinery area. The age estimation of the cores was calculated through the sedimentation rate of other cores collected nearby. In general, it was possible to observe an increase in the PAH concentrations and its derivatives over the years at four cores, being significant in the mid-20th century. This period in accordance with the growth TBS’s industrialization, urbanization and population increase promoted by the discovery and petroleum exploration. Temporal variations were observed for low molecular weight PAH (petrogenic sources) and high molecular weight PAH (petrogenic sources), mainly for the Aratu Port core, because was evident a change from petrogenic PAH in older sediments to a greater abundance of pyrogenic PAH in modern samples. The results of this work provide an insight into the historical inputs of PAH, NPAH, OPAH and PASH at cores impacted by different anthropic sources. The profiles of these pollutan have generally followed the historical development of BTS. Differences in the PAH concentrations and compositions, together with the presence of their derivatives NHPA, OHPA and PASH in the four sediment cores, indicated the different input intensities from anthropogenic sources. On the end of the 20th century and the beginning of the 21st century despite of decrease trend for PAH concentrations on Aratu Port and the refinery's cores, PASH concentrations showed maximum values in that time period.

     
2021
Thèses
1
  • LUISE CARVALHO DIAS
  • Development, validation and application of GC-MS/MS method for determination of nitrogen markers in petroleum

  • Leader : MARIA ELISABETE MACHADO
  • MEMBRES DE LA BANQUE :
  • ANTONIO FERNANDO DE SOUZA QUEIROZ
  • ELIANE LAZZARI
  • MARIA ELISABETE MACHADO
  • SERGIO LUIS COSTA FERREIRA
  • Data: 6 janv. 2021


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  • Nitrogen compounds (N-compounds) are a small fraction chemical composition of oil (0,1 to 2,0%) and are present mainly as aromatic and heterocyclic structures, classified in two groups: basic (pyridines, quinolines and benzoquinolines) and neutral (indoles, carbazoles and benzocarbazoles). Carbazoles their alkylated analogues and benzocarbazoles are used as geochemical markers (N-markers) provinging information about origin, migration, depositional environment and oil maturity. The determination of N-markers is conventionally performed by gas chromatography coupled to mass spectrometry (GC-MS) after sample pre-fractionation steps associated with a directed fractionation to separate the neutral from the basic nitrogen compounds. In this work, an analytical method was developed, validated and applied for the first time using gas chromatography coupled to triple quadrupole mass spectrometry (GC-MS/MS) for N-markers. Petroleum samples collected at eight points in the Potiguar Basin were analyzed without fractionation steps being the following Nmarkers determined: carbazole, 1-methylcarbazole, 2-methylcarbazole, 9-methylcarbazole, 1,8-dimethylcarbazole, 2,7-dimethylcarbazole, 3,6-dimethylcarbazole, 3-ethylcarbazole, 1,4,8-trimethylcarbazole, benzo[a]carbazole, benzo[b]carbazole, benzo[c]carbazole and dibenzocarbazole. The GC-MS/MS method in MRM mode, presented LOQ from 7,71 μg L-1 to 389,03 μg L-1 and LOD from 2,54 μg L-1 to 95,38 μg L-1 with determination coefficient values greater than 0,98. The precision tests resulted in relative standard deviation less than 20%. Recoveries between 78,63% and 117,34% were obtained. In the samples, the results obtained for the Nmarkers ranged from 0,29 ± 0,01 ug g-1 to benzo[c]carbazole in P6 and 59,74 ± 0,35ug g-1for 1,8-dimethylcarbazole in P1. The use of Principal Component Analysis (PCA) made it possible to differentiate samples from the lake environment and samples from the marine environment. Finally, diagnostic reasons based on correlation graphs according evaluation data of the quantitative assessment allowed to assess the environment of deposition and maturity.

2
  • GABRIEL DOS SANTOS RAMOS
  • SYNTHESIS OF BIS-1,2,3-TRIAZOLES 1,4-SYMMETRIC AROMATIC DISSUBSTITUTES VIA CuAAC REACTION WITH POTENTIAL LEISHMANICIDE ACTIVITY.

     



  • Leader : MAURICIO MORAES VICTOR
  • MEMBRES DE LA BANQUE :
  • MAURICIO MORAES VICTOR
  • SILVIO DO DESTERRO CUNHA
  • ROSSIMIRIAM PEREIRA DE FREITAS
  • Data: 2 mars 2021


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  • Previous work by the exaggerated group that some symmetrical aromatic bis-1,2,3-triazoles 1,4-disubstituted had a reduced leishmanicidal activity, so a second generation of bistriazoles of this class was proposed since it is proven in the literature that triazoles have activity leishmanicide, among others. Some of the physical-clustered characteristics that guarantee the biological activity of these compounds is a flat form of the triazolic ring that allows it to perform π-stacking interactions and a possibility to perform hydrogen bonds. Thus, a triazole was first synthesized as a test molecule for the study of the steps to be developed later in bistriazoles. Then, some symmetrical aromatic 1,4-disubstituted bis-1,2,3-triazoles were synthesized, varying as azides and the alkynes used, some of commercial origin while others were synthesized. Adopting as conditions previously studied in the test molecule, a bistriazole was oxidized in order to synthesize its hydrazone products. An in silico study was also carried out to evaluate the potential leishmanicidal activity of the compounds and a triazole and two bistriazoles with potential leishmanicidal activity were selected taking into account the previous results in in vitro tests carried out using the first generation bistriazoles.

3
  • ALZENIR RODRIGUES SOUZA
  • METABOLOMICS EVALUATION OF THE PLASMA OF CHILDREN AND ADOLESCENTS WITH SICKLE CELL ANEMIA

  • Leader : PAULO ROBERTO RIBEIRO DE JESUS
  • MEMBRES DE LA BANQUE :
  • PAULO ROBERTO RIBEIRO DE JESUS
  • ELISANGELA FABIANA BOFFO
  • LOURDES CARDOSO DE SOUZA NETA
  • CARLOS DANIEL SILVA DA SILVA
  • Data: 21 mai 2021


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  • Sickle cell anemia refers to a type of anemia in which the red blood cell acquires the shape of a sickle, causing vessel occlusion, that is, clogging of small vessels. It is characterized by physical discomfort in the bones and joints, acute abdominal pain, ulcerations of the lower limbs, and which is a form of hemolytic anemia. In this context, the objective of this work was to perform the metabolomic evaluation of the plasma of children and adolescents with sickle cell anemia who use hydroxyurea or not as a form of treatment. Blood plasma samples were subjected to pre-treatment protocols, which included protein precipitation and subsequent analysis by Nuclear Magnetic Resonance (1H NMR). The acquired spectra were processed in several online platforms for metabolomic analysis aiming at the identification and quantification of metabolites, as well as the performance of multivariate statistical analyzes. I Chenomx suite 8.4 was used for metabolite identification, and before the quantification, the alignment of the peaks was made, both performed in the NMRProcFlow program. The statistical analyzes performed in the MetaboAnalyst 2.0 program and included PLS-DA, cross-validation, VIP scores and Heat map. Twenty-four metabolites have been identified, including organic acids, amino acids, carbohydrates. Through statistical analysis it was possible to compare the metabolome of groups of patients and to show differences in metabolic profiles. This work shows the usefulness of metabolomics for the detection of biomarkers of sickle cell anemia, a disease that affects a significant portion of the Brazilian population, serving as a basis for future investigations involving the subject of this research.

4
  • PEDRO VICTOR BOMFIM BAHIA
  • Microscale extraction combined with gas chromatography/mass spectrometry for the simultaneous determination of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles in sediments

  • Leader : MARIA ELISABETE MACHADO
  • MEMBRES DE LA BANQUE :
  • MARIA ELISABETE MACHADO
  • GISELE OLIMPIO DA ROCHA
  • CLÁUDIA ANDRÉA LIMA CARDOSO
  • Data: 28 juil. 2021


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  • This paper describes a novel method based on an ultrasound-assisted extraction microscale device (UAE-MSD) for the rapid and simultaneous determination of polycyclic aromatic hydrocarbons (PAH) and polycyclic aromatic sulfur heterocycles (PASH) in marine sediments. Solvent extraction conditions were optimized by applying a simplex-centroid mixture design. Optimum conditions were used to validate and determine the concentrations of 17 PAH and 7 PASH. The best conditions were obtained by extracting sediments with 500 µmL of DCM:MeOH (65:35, v:v) over 23 minutes of sonication. Analytes were determined by gas chromatography/mass spectrometry in selective ion monitoring (GC-MS/SIM). Matrix effects were evaluated, and matrix-matched calibration was used for quantitation. Analytical method validation was carried out using the certified reference material NIST SRM 1941b, as well as sediment spiked with PASH at three concentration levels. Recoveries ranged between 70.0 ± 3.5% and 119 ± 9.1% for PAH and 80.6 ± 10.4% and 120 ± 10% for PASH. Linearity (R2) was ≥ 0.99 for all compounds. Method detection limits ranged from 8.8 to 30.2 ng g−1, while limits of quantification ranged from 29.4 to 1011 ng g−1. UAE-MSD was applied to marine sediments exposed to different anthropogenic impacts collected in Todos os Santos Bay, Brazil. PAH concentrations ranged from <LOQ to 667 ng g-1, while PASH levels were <LOQ to 1152 ng g-1. Dibenzothiophene was the compound presented in the highest concentration in all samples, with values up to 249 ng g-1. The results indicated contributions of pyrogenic sources from all compounds. The developed method can potentially be applied to extract trace levels of compounds in different solid matrices to minimize extraction time and solvent consumption.

5
  • Estéfane da Cruz Nunes
  • Metabolomics to understand neurological diseases: untargeted analysis of serum samples from infants with microcephaly.

  • Leader : GISELE ANDRE BAPTISTA CANUTO
  • MEMBRES DE LA BANQUE :
  • ERICA APARECIDA SOUZA SILVA
  • ANA VALÉRIA COLNAGHI SIMIONATO
  • ADRIANO QUEIROZ SILVA
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • GISELE ANDRE BAPTISTA CANUTO
  • LEONARDO SENA GOMES TEIXEIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • Data: 16 déc. 2021


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  • Zika is a disease caused by the Zika virus (ZIKV), whose main form of transmission is through the bite of Aedes aegypti and Aedes albopictus mosquitoes. The disease has been registered in more than 80 countries worldwide. ZIKV infection has been associated with several neurological disorders and auditory and vision abnormalities. A concern in the medical community revolves around infection during the gestation period, as ZIKV affects fetal development and can lead to pregnancy complications. One of the main consequences is congenital microcephaly, a neurological anomaly that causes a reduction in the newborn's head circumference. The knowledge of the impact of ZIKV on metabolism is scarce and is essential for the development of treatments and understanding of pathogenesis. Metabolomics, a comprehensive and quantitative analysis of the metabolites present in a biological system, is an interesting tool to obtain information about the metabolic alterations of several diseases, including ZIKV infection.
    In this work, the metabolic profile of serum samples from newborns with positive diagnoses for ZIKV, with and without microcephaly was evaluated using untargeted metabolomics. Sample treatment involved protein precipitation, followed by derivatization, using oximation and silylation reactions for subsequent analysis by gas chromatography hyphenated to mass spectrometry (GC-MS). Data were processed in XCMS software and metabolites identified in AMDIS. Statistical analysis using univariate and multivariate methods was applied to find discriminating metabolites. The results showed significant changes in metabolic pathways of amino acids, organic acids, carbohydrates and derivatives. The biological interpretation of these alterations indicates that microcephaly is associated with a reduction in carbohydrate levels caused by virus replication. The increase of amino acid in patients with microcephaly reinforces this relationship due to the involvement of glycolysis intermediaries in amino acid synthesis. Little is known about the metabolic changes caused by infection with ZIKV, especially in newborns. Thus, the results obtained in this study provide relevant information on the association between Zika and cases of microcephaly.

Thèses
1
  • EMMANUELLE FERREIRA REQUIÃO SILVA
  • ANALYTICAL STRATEGIES FOR DETERMINING THE CHEMICAL COMPOSITION IN OITI PULP AND PINHÃO SEED USING CHEMIOMETRIC TOOLS

     

  • Leader : ANA MARIA PINTO DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ANA MARIA PINTO DOS SANTOS
  • DÉBORA DE ANDRADE SANTANA
  • ERIK GALVÃO PARANHOS DA SILVA
  • MARIA ELISABETE MACHADO
  • VANIA PALMEIRA CAMPOS
  • WALTER NEI LOPES DOS SANTOS
  • Data: 28 janv. 2021


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  • This work investigated the chemical composition of oiti pulp and pine nuts using chemometric tools. Chapter 1 deals with the oiti approach oiti (Licania tomentosa (Benth.) Fritsch.), native fruit from Brazil, which is not vastly utilized in human diet due to the scarcity of information about its nutritional characterization. In this paper, the proximate composition, physical-chemical characterization, mineral content, bioactive compounds and antinutrients of oiti pulp were investigated. Multivariate analysis techniques (Kohonen Neural Network, PCA and HCA) were used to evaluate whether there were significant differences among the samples collected in the city of Salvador, Bahia, Brazil, regarding to nutritional composition. RNA-AG hybrid algorithm was applied to optimize the method used for total phenolic compounds determination. The samples were digested in microwave ovens using HNO3 and H2O2 oxidative mixture for multi-element determination of Ca, Cu, K, Mg, Mn, P and Zn by means of inductively coupled plasma optical emission spectrometry (ICP OES). Residual carbon content was determined to evaluate the efficiency of acid digestion procedure. The method accuracy was confirmed by spinach leaves certified reference material analysis (1570a) and apple leaves (1515) from the National Institute of Standards and Technology (NIST). The results indicate that oiti pulp can contribute to human health due to its nutritional value and its natural antioxidant properties, enabling applications in the pharmaceutical industry and new food products development. In chapter 2, the focus of the study was the pine seed (Araucaria angustifolia (Bertol.) Kuntze) rich in nutrients and the neutral flavor can be very versatile in South American cuisine. Thus, the study aimed to determine and chemiometrically evaluate minerals, proximate composition and toxic element in pine nuts (raw and cooked), marketed in five Brazilian states, such as: Minas Gerais, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul. The methodology used consisted of pine nuts acid digestion (fresh and cooked) from five Brazilian states in HNO3 / H2O2 mixture in a digestor block. The exploratory analysis was carried out by usage of chemometric tools generating Boxplot, PCA and HCA graphs in R software, thus allowing to get relevant information regarding the cooking effect on the minerals present in the pine nuts. Therefore, it was possible to discriminate the samples regarding the preparation methods (raw and cooked), in which the raw samples indicated the highest concentrations of the analyzed analytes, although the cooked samples showed leaching of nutrients into the cooking water during cooking process. Therefore, this information is necessary for a better understanding of Brazilian pine nuts nutritional value, which can be used in the development of new culinary dishes and for therapeutical diets.

2
  • LUANA ARAÚJO OLIVEIRA
  • DETERMINATION OF TALLIUM IN WATER SAMPLES BY HIGH RESOLUTION ATOMIC ABSORPTION SPECTROMETRY WITH CONTINUOUS SOURCE IN GRAPHITE OVEN USING DIRECT SAMPLING OF SOLIDS AFTER PRE-CONCENTRATION ON CHROMATOGRAPHIC FILTER PAPER

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • ANA MARIA PINTO DOS SANTOS
  • GISELE ANDRE BAPTISTA CANUTO
  • ERIK GALVÃO PARANHOS DA SILVA
  • JORGE LUIS OLIVEIRA SANTOS
  • Data: 8 févr. 2021


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  • Due to the high degree of thallium toxicity and possible contamination of the environment due to the natural presence or by anthropic action in this paper, a simple and fast method for the separation and pre-concentration of thallium in water samples using paper is proposed. chromatographic filter as a solid support with subsequent determination by using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis(SS HR-CS GF AAS). The chromatographic filter paper disk and EDTA solution were used as the solid phase and masking agent respectively. An investigation of the variables that influence the pre-concentration, such as the pH of the sample, stirring time, sample volume, effect of other species, type and concentration of the masking reagent, was carried out. After optimizing these variables, the analytical method developed showed a preconcentration factor of 57, an precision of 9.4% (thallium solution 10 μg L -1), a limit of detection of  0.0169 µg L-1 and a limit of quantification of 0.0563 µg L-1. Addition and recovery tests were performed and the results varied from 91% to 110%.The accuracy of the method was assessed by analyzing the certified reference material of TDMA 52.4 fortified water and by analyzing water samples using a comparative method that employed an inductively coupled plasma mass spectrometer (ICP-MS). The procedure was applied for the determination of thallium in water samples collected in the city of Barreiras, Bahia, Brazil. The thallium concentrations present in the analyzed samples ranged between 0.0814 and 0.802 μg L-1. The method proved to be simple, fast, efficient and easy to perform for the determination of thallium by SS HR-CS GF AAS.

3
  • RICARDO LEAL CUNHA
  • SYNTHETIC DRUGS IN BAHIA AND SERGIPE: STUDY ON THE PREVALENCE OF AMPHETAMINE TYPE STIMULATORS AND NEW PSYCHOACTIVE SUBSTANCES.

  • Leader : PEDRO AFONSO DE PAULA PEREIRA
  • MEMBRES DE LA BANQUE :
  • JOSÉ LUIZ DA COSTA
  • PEDRO AFONSO DE PAULA PEREIRA
  • SANDRO NAVICKIENE
  • SILVIO DO DESTERRO CUNHA
  • VANIA PALMEIRA CAMPOS
  • WILSON ARAUJO LOPES
  • Data: 25 févr. 2021


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  • The illicit market for synthetic drugs is characterized by the wide variety of psychoactive substances of different chemical and pharmacological classes, such as amphetamine-type stimulants and new psychoactive substances that have appeared more frequently in this market in the last twenty years. A recent report released by the Oswaldo Cruz Foundation in July 2019, showed that approximately 33.8% of young Brazilians between 12 and 34 years old have consumed some illegal substance throughout their lives. In view of this scenario, knowledge about the chemical composition of these drugs, the nature and quantity of the active substances present, is relevant in several aspects. The main one is related to public health and the need for adequate medical care for people who ingest hitherto unknown psychoactive substances. Another important aspect is the knowledge about the composition of these drugs apprehended by the police, in order to establish adequate chemical and toxicological analysis procedures in the forensic laboratories. In this study, 21 substances were identified among classic synthetic drugs and new psychoactive substances, in seizures that occurred in 17 cities in Bahia and Sergipe, using GC-MS, FTIR and NMR. In order to investigate the composition of ecstasy and amphetamine stimulants, seized between 2014 and 2019, an analytical method was developed to determine 12 substances of interest using GC-MS. Analyzes of 203 tablets showed that MDMA, the main component of ecstasy, was found in 57% of the samples, in amounts between 27.3 –187.1 mg / tablet. Mixtures of MDMA, MDA, caffeine and synthetic cathinones were observed in 34% of the analyzed ecstasy tablets. Analyzes of illicit tablets of “Nobésio” showed that clobenzorex and caffeine were the only substances found in 93% of the samples in amounts between 2.15 - 34.5 mg/tablet and 4.94 - 118.3 mg/tablet, respectively. After these findings, an analytical method was developed to determine 11 synthetic drugs in 50 blood samples, employing protein precipitation and LC-MS / MS, with the aim of investigating the use of these drugs in post-mortem cases. In five samples, MDMA, MDA, amphetamine and clobenzorex were identified, in concentrations ranging from <5.0 ng/mL (MDMA) to 389.3 ng/mL (amphetamine). These results have shown that the illicit trade in synthetic drugs in these states has significantly contributed to indiscriminate consumption and the occurrence of cases of intoxication in several fatal events.

4
  • LEONARDO BRITO DA SILVA
  • EFFECT OF THE METHOD OF PREPARATION AND THE ADDITION OF MAGNESIUM ON THE PROPERTIES OF LANTANIUM AND NICKEL CATALYSTS OBTAINED FROM PEROVSKITAS

  • Leader : MARIA DO CARMO RANGEL SANTOS VARELA
  • MEMBRES DE LA BANQUE :
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • ZENIS NOVAIS DA ROCHA
  • PAULO ROBERTO RIBEIRO DE JESUS
  • RAILDO ALVES FIUZA JUNIOR
  • ANDRE ROSA MARTINS
  • CESÁRIO FRANCISCO DAS VIRGENS
  • Data: 10 mars 2021


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  • Due to the increase in oil consumption and its contribution to the greenhouse effect, the  development of new routes for generating clean and renewable energy is much needed The use of biogas, obtained by anaerobic digestion of biomass, is an attractive alternative because it is a renewable resource. Among the various uses of biogas (mixture of methane and carbon dioxide), one of the most important is its catalytic transformation to generate renewable hydrogen, considered the main energy vector of the future. This process can be conveniently carried out through dry reforming of biogas, which has the advantage of consuming two gases responsible for the greenhouse effect. The main catalysts used in this process are based on platinum, iridium, rhodium, nickel and cobalt, among others. To reduce the costs and increase activity, selectivity and resistance to coke, the properties of metals can be combined. In this work, the effect of magnesium addition and preparation methods on the properties of precursors, perovskite oxides (La1-xMgxNiO3; x = 0.0; 0.1; 0.5; 0.9) and of nickel catalysts supported on lanthanum oxide for dry reforming of methane, as a model reaction of biogas. The catalysts were obtained by reducing the perovskites, in order to obtain solids with highly dispersed active phase (nickel). The precursors were prepared by the amorphous citrate, coprecipitation/impregnation and combustion methods. The samples were characterized by thermogravimetry, X-ray diffraction, temperature programmed reduction, nitrogen adsorption and desorption and temperature programmed desorption. The catalysts were evaluated in dry methane reforming, at 750 ° C, for 6 h, using a methane to carbon dioxide ratio of 1. The amount of carbon deposited on the catalysts, during reaction, was quantified by thermogravimetry, elemental analysis (C, H and N) and temperature programmed oxidation. Different crystalline phases were observed, depending on the preparation method and on the presence and magnesium content in the solids. Pure perovskite (LaNiO3) was only obtained by the amorphous citrate method, regardless of the magnesium content. In the other cases, other phases were detected coexisting with perovskites. Regardless of the preparation method and the magnesium content, the samples showed low specific surface areas, which is characteristic of the nature of these solids. On the other hand, the interactions between metal and support varied according to the method of preparation and the magnesium content. The total acidity of the solids varied with the magnesium content, in different ways, depending on the method of preparation, but the formation of strong and moderate acid sites was always favored by magnesium. The catalysts prepared by the citrate method led to high conversions of methane and carbon dioxide and hydrogen yield, but low yields of carbon monoxide, resulting in H2/CO ratios above the stoichiometric one. The H2/CO ratios varied between 7.0 and 11.0 during reaction, the richest magnesium catalyst leading to the highest value, while the magnesium-free catalyst leading to the lowest value, among all solids. These results show that the catalysts prepared by the citrate method are promising for the production of  hydrogen and synthesis gas rich in hydrogen, being able to control the content of hydrogen or carbon monoxide by magnesium content.

5
  • KELLY RODRIGUES DOS SANTOS
  • Solidification/Stabilization (S/S) of Fe, Ni, Sb and V in cement pastes containing an equilibrium catalyst (Ecat)

  • Leader : HELOYSA MARTINS CARVALHO ANDRADE
  • MEMBRES DE LA BANQUE :
  • ALLISON GONÇALVES SILVA
  • ARTUR JOSE SANTOS MASCARENHAS
  • FRANCISCO GABRIEL SANTOS SILVA
  • HELOYSA MARTINS CARVALHO ANDRADE
  • JARDEL PEREIRA GONCALVES
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 16 avr. 2021


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  • One of the main problems faced by industries is the proper management of waste. In the oil industry, for example, huge amounts of spent catalysts in fluidized bed catalytic cracking(FCC), also called Ecat, are produced worldwide. This residue has potentially toxic elements in its composition, such as iron (Fe), nickel (Ni), vanadium (V) and antimony (Sb). The disposal of Ecat without a proper pre-treatment is not tolerable. The use of the solidification/stabilization (S/S) technique of this residue in cement pastes was evaluated and leaching is an important evaluation means of this treatment, used to predict the degree of efficiency in fixing dangerous constituents in the treated waste. The aimof this thesis was to investigate the use of the S/Smethod to immobilize Fe, Ni, Sb and V from Ecat, usinga Portlandcement as binder. Leaching tests were applied according to the Toxicity Characteristic Leaching Procedure(TCLP 1311), using fresh waterand natural sea water,in different pH. Considering thecoprocessing of various residues in the manufacture of cement, the leaching of chromium and its speciation werealso investigated. Pastes were produced using Special ClassPortland cement(CPE) and15% Ecat. The results showed, in its entirety, that the CPE was efficient in immobilizing the evaluated elements (Fe, Ni, Sb and V). The retention percentage in the paste was 94% for Fe;91% for Ni;90% for V and 74% for Sb. It was observed that the element retention rate was higher in fresh water than in sea water or under TCLP 1311 conditions. This behavior was attributed to the attack of salts present in sea water. Despite this, the element retention rates varied between 73 and 85% after leaching in seawater. Concerning to Cr, the anhydrous CPE showed in its composition 48.70 mg kg-1of total Cr and the speciation of Cr in the leachate of the paste produced with CPE showed 1.881mg kg-1of Cr(VI) in TCLP solution and 1.178 mg kg-1of Cr(VI)in fresh water. In seawater, the Cr(VI) concentration was 23.88 mg kg-1, confirming the more aggressive attack of this environment. It was possible to infer that the S/S technique can be used, considering that all leached concentrations were below the limits established by environmental regulations. As for the evaluation of the cement used, the studies carried out confirmed the presence of Cr and Cr(VI). The toxicity of this species emphasizesthe importance of regulations that define thelimitsfor the presence of this and other contaminants in cement.

6
  • MADSON MOREIRA NASCIMENTO
  • Determination of persistent organic pollutants in water samples by dispersive micro-solid extraction followed by gas chromatography and mass spectrometry

  • Leader : GISELE OLIMPIO DA ROCHA
  • MEMBRES DE LA BANQUE :
  • EMANUEL CARRILHO
  • GISELE OLIMPIO DA ROCHA
  • JAILSON BITTENCOURT DE ANDRADE
  • MARCO TADEU GRASSI
  • MARIA ELISABETE MACHADO
  • SERGIO LUIS COSTA FERREIRA
  • Data: 26 avr. 2021


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  • A significant amount of recently published papers has been shown an expressive advance in the synthesis and characterization of new and selective sorbents. However, there is a scarcity of papers reporting the development of new customized devices for the improvement of dispersive micro-solid phase extraction technique. In this work, it was developed analytical procedures for extraction/preconcentration of organic pollutants in water samples based on dispersive micro-solid phase extraction technique. For this purpose, new and effective devices were designed to perform extraction and micro-desorption steps. In the first developed procedure, the devices were employed in the extraction/preconcentration of polycyclic aromatic hydrocarbons from fresh and marine waters. The experimental conditions were optimized and the extraction parameters were set as 100 mg of C18, extraction by 32 min, and micro-desorption of 20 min with 500 μL of n-hexane. After validation, the analytical procedure provided limit of detection values ranging from 0.8 ng L-1 (Phenanthrene) a 1.70 μg L-1 (9,10-Phenanthrenequinone) and relative recoveries ranging from 59.1 % a 124 % (1-Methyl-6-Nitronaphthalene). The enrichment factor ranged from 39 (1,4-Naphthoquinone) to 400 (fluorene). The procedure was successfully applied in the determination of PACs in fresh and marine waters and their concentrations in the water samples ranged from 7.94 ng L-1 (Naphthalene) to 38.4 ng L-1 (Phenanthrene). An evaluation based on Analytical Ecoscale showed that the proposed procedure reached 92 % points, being considered an environmentally friendly procedure. In the second developed procedure, the extraction and microscale devices were employed in the extraction of pesticide residues from fresh and marine waters. The procedure was optimized through experimental design techniques and the optimal extraction conditions were: 30 min of extraction time, 6.74 % of NaCl added into 100 mL of the water sample, and 24 min of micro-desorption with 500 μL of ethyl acetate. The detection limits ranged from 0.51 ng L-1 (4,4-DDE) a 22.4 ng L-1 (dimethoate), and relative recoveries ranged from 74.2 % (endrin) to 123 % (molinate). In addition, it was obtained enrichment factor ranging from 72,5 (dimetoate) to 200 (tebuconazole). The analytical procedure was applied in the extraction of pesticide residues in fresh and marine waters. Pesticides such as malathion, dimethoate, and lambdacyhalothrin, which are commonly applied in Brazil, were detected in concentrations ranging from <LD to 120 ng L-1 (dimethoate). The third procedure consisted of the development of a Three Ways Device for Filtration and Solid-Liquid Microextraction. The prototype of a 3D imprinted device was assessed through preliminary experiments in the extraction of polycyclic aromatic hydrocarbons using 100 mL of a real water sample. The results showed that the prototype was successfully employed in the extraction steps and injections into GC-MS. However, it was obtained low enrichment factors for some PAHs, evidencing the need for additional adjustments on the device.

7
  • ARIANA MARIA DOS SANTOS LIMA
  • CHARACTERIZATION OF MINERAL NUTRIENTS AND DETERMINATION OF PESTICIDES IN VEGETABLES CONSUMED IN THE CITY OF SALVADOR, BAHIA

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • JOAO BATISTA PEREIRA JUNIOR
  • ANA MARIA PINTO DOS SANTOS
  • ANDERSON SANTOS SOUZA
  • DÉBORA DE ANDRADE SANTANA
  • Data: 6 mai 2021


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  • In this work, two methods of determination of minerals, present in chapter I and pesticides, in chapter II, were developed, both aiming to nutritionally evaluate mustard and chicory vegetables consumed in the city of Salvador, Bahia. In the first chapter, two grams of mustard and chicory samples were digested in a block for two hours, using 3 and 4 mL, respectively, of acid and 1 mL of hydrogen peroxide, the minerals (Ba. Ca, Fe, K, Mg, Na, P, S e Zn) were determined using ICP OES. To validate the method, the merit parameters were obtained, the precision was between 0.2-8.8%, the LD and LQ values were considered satisfactory, and the accuracy evaluation was due to the use of the CRM NIST 1515 sheets of apple, which considering the t-test and the F-test, within a 95% confidence interval confirms the accuracy of the method. The different cooking methods were evaluated: steam, cooked in a conventional stove and microwave. With the results, it was possible to infer that the cooking process influences the composition and availability of nutrients, showing the pattern of nutrient loss: raw>steam>cooked>microwave, while the PCA and HCA allowed to recognize that the samples that passed by the same cooking method they formed the four distinct groups, indicating the similarity of the samples and the LDA allowed a clear separation of classes between the samples of each type of cooking, with rates of 100% selectivity, accuracy and without the presence of false positives or negative. In the second chapter, an adapted method was developed using the low temperature partition technique in order to determine twenty-six pesticides by GC-MS, consisting of the extraction of 4g of sample previously macerated with a combination of ethyl acetate/water ( 8:1, v/v), this mixture is vortexed for 10 min, centrifuged for 3 minutes at 300 rpm and taken to the freezer (-20ºC) until freezing, approximately 3h. The results obtained were satisfactory with good linearity (r2: 9936-0.9994), LD ranging from 0.1-0.4 μg L-1 and LQ ranging from 0.34-1.9 μg L-1. The inter and intra-day precision were within the reference parameters, between 6.3-23.4% and 2.7-18.3%, respectively. To verify the accuracy, three-level fortification recovery tests were performed and all results were above a 70% recovery. All data indicate that the method is robust, accurate and reliable. Of the twenty-five pesticides studied, three had concentrations below the detection limit and thirteen were not detected, indicating the absence of these substances in the samples, but three pesticides were detected with concentrations above the maximum limit allowed by legislation.

8
  • THAIONARA CARVALHO MATOS
  • Distribution of Trace Elements in Soils in Salvador City.

  • Leader : VANIA PALMEIRA CAMPOS
  • MEMBRES DE LA BANQUE :
  • VANIA PALMEIRA CAMPOS
  • PEDRO AFONSO DE PAULA PEREIRA
  • AMAURI ANTONIO MENEGARIO
  • MADSON DE GODOI PEREIRA
  • VALFREDO AZEVEDO LEMOS
  • WANDER GUSTAVO BOTERO
  • Data: 21 mai 2021


  • Afficher le Résumé
  • Population agglomeration, combined with intense anthropic activity in the capital of Bahia, generates a large amount of waste that tends to reach different ecosystems, changing them continuously. Of these, it is worth mentioning the terrestrial whose soil matrix, object of study of this work, can be a vehicle of human exposure to elements present in these residues. Despite the effects of impacts on the soil, it is not possible to find works related to its physical-chemical characteristics, the main source being those that are present in the soil map. Therefore, the relevant data are associated with the original composition of the matrix rock and not with the effects of urbanization. So, to expand the information in the database on soils in the municipality of Salvador-Ba, this work aims to characterize its soils, collected in areas with high circulation of people and vehicles. For this, the samples were characterized physically-chemically through the following parameters: pH, organic matter content, particle size, infrared analysis, x-ray diffraction. Furthermore, the contents of 24 elements (Al, An, As, Ca, Cd, Pb, Co, Cr, Cu, S, Sn, Sr, Fe, P, Li, Mg, Mn, Mo, Ni were determined , K, Se, Na, V and Zn), via ICP OES. From theselected elements to be quantified, only 12have shownvalues above the limit of quantification (Al, Ca, Cr, Pb, Cu, Sr, Fe, Mg, Mn, K, V and Zn). In general, the concentration of these elements are lower than theenvironmental quality standard for soilsof the National Environment Council (CONAMA). However, whenthey areconfronted with evaluations of Pollution Index (IP), Geo-accumulation Index (Igeo) and Enrichment Factor (FE), it is noticed that their values fit into a situation of environmental attention, as they indicate significant contamination dueto their accumulation by local contamination source or by several sources. These data have beenmore prominent for Al, V and Sr, elements of wide application in items such as car construction and objects of daily use. They havebeenobtained through two partial extraction methods:one involving pseudo-total extraction with a wet digestion under heating with a mixture of nitric acid and hydrogen peroxide andother of elements involving hydrochloric acid solution under mechanical stress. Comparing the data of both methods, there is a favoring of the elements in the phyto-availablepart, that is, a prevalence of the elements preferably in the ionic form thataremore available for mass exchanges in the rhizosphere. Therefore, in the phyto-available part,the IP, Igeo and FE of some elements(Cu, Sr e Pb)arehigher than expectedvaluesin relation to the pseudo-total fraction.

9
  • JULIANA GUERREIRO CEZAR
  • SYNTHESIS AND CHARACTERIZATION OF RUTENUM AND COBALT COMPLEXES WITH CYCLIC ALIPHATIC AMINES: INTERACTION STUDIES WITH NITROGEN BASES AND DNA
  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • MARCOS MALTA DOS SANTOS
  • SORAIA TEIXEIRA BRANDAO
  • LUIZA AMIM MERCANTE
  • KLEBER QUEIROZ FERREIRA
  • CARLOS DANIEL SILVA DA SILVA
  • ROSENIRA SERPA DA CRUZ
  • Data: 6 août 2021


  • Afficher le Résumé
  • Coordination compounds have fundamental importance in biological processes, since they bind and interact with molecules/biomolecules indispensable to life. In this sense, complexes containing aminoacids as binders have been synthesized, as these systems facilitate studies of the coordination of metal ions with DNA, which, in turn, indicates a potential biological application. Non-heme macrocyclic ligands are also important in chemical coordination, which is due to the presence of this type of ligand in the structures of a large number of biologically important complexes, as well as the kinetic and thermodynamic stability that these ligands confer on the complexes. NO plays key roles in several biological processes that depend on their local concentration, motivating the development of NO-releasing/capture metallo-drugs. This thesis is an investigation of the interactions of Ru and Co complexes with biomolecules, such as nitrogenous bases and DNA, aiming at the development of metal-pharmaceuticals, using as co-ligands macrocycles and nitric oxide. The unpublished complexes synthesized were: cis-[Ru(dmso)2(R-cyclen)]Cl, [Co(Met)L(mac)]n+ , cis- [Ru(Met)2(mac)]+ and [Ru(NO)(Met)(mac)]2+ . Analysis of the vibrational spectra showed the appearance of bands characteristic of the methionine and macrocyclic ligands (cyclam / cyclen/ R-cyclen), as well as allowed to assign the assignment of the monodentate coordination mode for the bond between the carboxylic group of the amino acid and the metal center. For complex nitrosyls, the identification of a characteristic band of NO in the form of NO+ is also noteworthy. The electron spectra presented bands associated with d-d and MLCT transitions and, for the Ru(II) complexes of LMCT. Electrochemical studies allowed evaluating the redox processes centered on the metallic center, with evidence of a coupled reaction with the formation of an aquacomplex, in addition to qualitatively investigating the release of methionine (or DMSO, for the complex with substituted cyclen), when submitted to electrochemical stimulation. Preliminary kinetic reactivity data confirm the aquation of chloride and DMSO in the complexes trans-[CoCl2(cyclam)]Cl and cis-[Ru(dmso)2(R-cyclen)]Cl, respectively, and confirm the entry of amino acid while the water molecule leaves the Co(III) coordination sphere. Interaction studies of chlorocomplexes with DNA were sufficient to suggest that these complexes interact with DNA. 1H NMR data, together with spectroscopic and electroanalytical analysis, confirm the proposed structures for the new complexes. Therefore, the results obtained support the formulation of the new synthesized complexes, as well as suggest the interaction of the respective chlorocomplexes with DNA.

10
  • DANIEL LEVI FRANÇA DA SILVA
  • ANALYTICAL STRATEGIES FOR DETERMINING Cd AND Hg USING ATOMIC FLUORESCENCE SPECTROMETRY WITH CHEMICAL VAPOR GENERATION.

  • Leader : WALTER NEI LOPES DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • WALTER NEI LOPES DOS SANTOS
  • JOAO BATISTA PEREIRA JUNIOR
  • ANTONIO FERNANDO DE SOUZA QUEIROZ
  • CESAR RICARDO TEIXEIRA TARLEY
  • DOUGLAS GONÇALVES DA SILVA
  • Data: 3 sept. 2021


  • Afficher le Résumé
  • In this present work, analytical strategies for the determination of Cd and Hg in sea water samples using Atomic Fluorescence Spectrometry with Cold Vapor Generation (CV AFS) were applied. For the development of the method an adaptation in the cold vapor generation system was performed. To reduce the sample/reagent consumption and improving the stability of the analytical signal of the technique. The multivariate optimization methodology was also employed, for both analytes. Beginning with a complete two-level factor design (23 ), which was used to evaluate the trend of the variables: HCl concentration, NaBH4 concentration and carrier gas flow (CGF). Within the established experimental domain all factors were statistically significant, as well as the interaction between them. After the screening stage, a Box-Behnken design was applied to optimize the cold steam generationconditions. The results of the optimization were evaluated through the Analysis of Variance (ANOVA), graphs of residues versus predicted values and predicted versus observed values, demonstrating that the factors are statistically significant and that the generated model adequately represents the proposed method, obtaining as critical values0.408 and 0.41 mol L-1 of [HCl], 2.80 and 3.86 %(m v-1 ) of [NaBH4] and 0.27 and 0.19 mL min-1 of CGF for Cd and Hg, respectively. Furthermore, a univariate study to evaluate the influence of L-cysteine and cobalt II concentrations on the cold steam generation process was performed. The proposed method allowed the determination of cadmium and mercury with detection limits (3σ/S) of 0.16 and 0.20 ng L-1 , accuracy from the relative standard deviation (RSD) of ERM CA713 of 4.3 and 3.4 % for Cd and Hg, respectively. The accuracy of the method was confirmed by analysis of the residual water reference materials (CA713), oyster tissue (NIST 1566b), spinach leaf (NIST 1570a) and San Joaquin soil (SRM 2709a). A calibration study of the method was carried out to validate that the proposed method does not suffer interference from the sea water matrix. Moreover, the method was satisfactorily applied to three sea water samples collected in the region of Salvador-BA, Brazil. The concentrations of Cd and Hg in the samples are in accordance with those found in the literature and presented values below the maximum limits allowed by the resolution of CONAMA 357/2005 for saline waters class II.

11
  • DANIEL MOREIRA ARAÚJO
  • Preparation of nitrogen compounds and application of chemometry for greater efficiency of mechanochemistry in the synthesis of synthetic intermediates

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • JORGE MAURICIO DAVID
  • SERGIO LUIS COSTA FERREIRA
  • BRUNO OLIVEIRA MOREIRA
  • AMENSON TRINDADE GOMES
  • Data: 5 oct. 2021


  • Afficher le Résumé
  • In this work, nitrogen compounds were prepared such as the new thiocarbohydrazone (N,N-Bis(alpha-methyl-cinnamal)thiocarbohydrazone) obtained by wet method with 74% yield. Furthermore, bisthiocarbohydrazones were prepared via mechanochemistry, which achieved yields of 54% to quantitative, shorter reaction time, and E-factor 225 times lower than previous works. From the bisthiocarbohydrazones three new bistetrazoles were prepared using bismuth as the inorganic thiophile. The application of chemometry in organic synthesis was evaluated by the number of publications from 2014 to 2020, where it was observed that the number of publications is still incipient in this topic. To contribute to this theme, chlorinated derivatives of acetanilide were obtained via mechanochemistry and the use of chemometry to optimize the process. This type of approach has shown increasing use in organic synthesis, due to its effectiveness in product yield optimization.

12
  • CHEILANE TAVARES DE SOUZA
  • DEVELOPMENT OF PORTABLE SPECTROPHOTOMETRIC AND FLUORIMETRIC ANALYTICAL SYSTEMS BASED
    ON DIGITAL IMAGES
  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • ANDERSON SCHWINGEL RIBEIRO
  • IVANICE FERREIRA DOS SANTOS
  • JOAO BATISTA PEREIRA JUNIOR
  • MARIA ELISABETE MACHADO
  • SERGIO LUIS COSTA FERREIRA
  • Data: 8 oct. 2021


  • Afficher le Résumé
  • In the present work, portable systems for analytical determinations based on digital image analysis were developed and applied. The first chapter presents general information about the use of color information, from digital images, to build the analytical signal. The second chapter presents the development of a portable spectrophotometric system that employs a 3D device to attach a webcam as a detection system; the system is fully powered by a computer's USB ports and makes use of an LED as a radiation source, powered by an adjustable voltage source. The preliminary performance of the system was evaluated in iron
    (II) and hypochlorite determinations, using color data from the RGB space and the effective absorbance mathematical processing. The system showed good analytical performance placing the LED on top of the cuvette and radiation source with maximum intensity. The third chapter presents the application of the spectrophotometric system developed in the determination of the external marker, titanium dioxide, in bovine feces. The method presented detection and quantification limits of 0.57 and 0.85 mg 100g-1, respectively; linear working range from 0.85 to 10 mg 100g-1 and accuracy, expressed in terms of RSD, of 1.86%. The accuracy of the method was verified by comparing the results found by the proposed method with the reference spectrophotometric method and there was no significant difference. The fourth chapter presents a portable fluorimetric system, which makes use of a monochromatic LED in the excitation stage, to determine quinine in commercial samples of tonic water. The system presented satisfactory performance, with a linear working range from 0.99 to 10 mg L-1, correlation coefficient equal to 0.998 and average precision (RSD) of 1.14%. The samples had quinine contents from 47.8 to 66.7 mg L-1, within the standards
    established by current legislation. The developed systems showed good performance, proving to be promising, alternatives to the reference methods, for analytical determinations based on digital image analysis.

13
  • IVA SOUZA DE JESUS
  • NEW FORMAL [3+3]CYCLOADDITION REACTIONS OBETWEEN 3-CARBOXICUMARINS AND ENAMINONES IN THE SYNTHESIS OF CARBO- AND POLYFUNCTIONALIZED HETEROCYCLES

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • ANTONIO CARLOS BENDER BURTOLOSO
  • FERNANDA ANDREIA ROSA
  • MAURICIO MORAES VICTOR
  • ROSSIMIRIAM PEREIRA DE FREITAS
  • SILVIO DO DESTERRO CUNHA
  • VERA LUCIA EIFLER-LIMA
  • Data: 12 nov. 2021


  • Afficher le Résumé
  • In this work, the study of the reactivity of coumarino-3-carboxylic acids against the five-membered cyclic enaminones in formal aza-[3+3] cycloaddition reactions was carried out for the first time. Thus, 08 new polyfunctionalized indolizidine core were obtained with satisfactory yield (47-94%) and 03 new dihydropyridones in yields between 59 and 68% were obtained. Additionally, from synthetic applications of suitable indolizidinones, it was possible to access new coumarin-indolizidinic hybrids via trans-ring reactions, promoted by Fe(acac)3 and oxidative aromatization reactions, catalyzed by Pd/C (10 mol%). In addition, the reactivity of coumarin-3-carboxylic acids to secondary acyclic enaminones was investigated to obtain 10 unprecedented cyclohexenones, with an adequate level between 70 and 99%. In addition, two new azabicycles were accessed from reactions between primary acyclic enaminones and coumarin-3-carboxylic acid.

14
  • IVA SOUZA DE JESUS
  • NEW FORMAL [3+3]CYCLOADDITION REACTIONS OBETWEEN 3-CARBOXICUMARINS AND ENAMINONES IN THE SYNTHESIS OF CARBO- AND POLYFUNCTIONALIZED HETEROCYCLES

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • MAURICIO MORAES VICTOR
  • JORGE MAURICIO DAVID
  • VALERIA BELLI RIATTO
  • ANDRE ALEXANDRE VIEIRA
  • ANTONIO CARLOS BENDER BURTOLOSO
  • VERA LUCIA EIFLER-LIMA
  • DIMAS JOSÉ DA PAZ LIMA
  • FERNANDA ANDREIA ROSA
  • KLEBER THIAGO OLIVEIRA
  • ROSSIMIRIAM PEREIRA DE FREITAS
  • Data: 12 nov. 2021


  • Afficher le Résumé
  • In this work, the study of the reactivity of coumarino-3-carboxylic acids against the five-membered cyclic enaminones in formal aza-[3+3] cycloaddition reactions was carried out for the first time. Thus, 08 new polyfunctionalized indolizidine core were obtained with satisfactory yield (47-94%) and 03 new dihydropyridones in yields between 59 and 68% were obtained. Additionally, from synthetic applications of suitable indolizidinones, it was possible to access new coumarin-indolizidinic hybrids via trans-ring reactions, promoted by Fe(acac)3 and oxidative aromatization reactions, catalyzed by Pd/C (10 mol%). In addition, the reactivity of coumarin-3-carboxylic acids to secondary acyclic enaminones was investigated to obtain 10 unprecedented cyclohexenones, with an adequate level between 70 and 99%. In addition, two new azabicycles were accessed from reactions between primary acyclic enaminones and coumarin-3-carboxylic acid.

15
  • RAINELDES AVELINO CRUZ JUNIOR
  • Development of analytical methods based on UV/H2O2 photo-oxidation for the determination of metals in alcoholic beverage samples using atomic absorption spectrometry with electrothermal atomization
  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • WALTER NEI LOPES DOS SANTOS
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • EDWIN PALACIO
  • MARIANA ANTUNES VIEIRA
  • Data: 26 nov. 2021


  • Afficher le Résumé
  • In this work, a complete study was developed on methodologies applied to beverage analysis, as well as presentation of a methodological proposal for sample preparation. The consumption of beverages, such as wine, around the world has been increasing significantly, as well as the sophistication of its mode of production. With this the need for sophisticated analytical methodologies for the determination of chemical species that help in the quality control, bioavailability and authenticity process of the product regarding the possible adulterations that may occur, become indispensable. The first chapter of this work focuses on bringing a descriptive qualitative bibliographic review on the most relevant works on the subject.

    The second chapter presents a proposal of sample preparation method by photo oxidation using ultraviolet radiation in the process of decomposition of wine samples for pb determination. The limits of quantification and detection found were 0.89 μg L−1 and 0.27 μg L−1, respectively. The system was applied to different wine samples resulting in concentrations ranging from 2.19 to 43.48 μg L−1 of lead.

    The third chapter of this work proposes an online system employing 70% hydrogen peroxide (p/ p) and UV radiation for the determination of chromium in beer samples by electrothermal atomization atomic absorption spectrometry (ETAAS). The experimental factors were optimized using a complete factorial planning of two levels. The kinetic curves of degradation of the samples under different conditions were also evaluated. The apparent kinetic constant (kapp) found for the process was 0.0668 min -¹ (R² = 0.9936). The online digestion procedure allowed the determination of chromium in beer samples by ETAAS, using the external calibration technique, with analytical line 357.9 nm, in the presence of magnesium as a chemical modifier with limits of detection and quantification of 0.86 and 2.90 μg L -¹, respectively. The accuracy of the method was confirmed by the analysis of the reference material. The concentrations found ranged from 4.26 to 33.28 μg L-1.

16
  • CÍNTIA MARIA CARNEIRO FRANCO LIMA
  • Isoindigo and azaisoindigo: synthesis, characterization, preparation of functionalized analogues and evaluation of their biological activity against SARS-Cov-2
  • Leader : MAURICIO MORAES VICTOR
  • MEMBRES DE LA BANQUE :
  • MAURICIO MORAES VICTOR
  • VALERIA BELLI RIATTO
  • SILVIO DO DESTERRO CUNHA
  • LUIZ CLÁUDIO DE ALMEIDA BARBOSA
  • BÁRBARA VASCONCELLOS DA SILVA
  • Data: 10 déc. 2021


  • Afficher le Résumé
  • This doctoral thesis for the Graduate Course in Chemistry is an approach of the synthesis of heterocyclic substances such as derivatives of isoindigo and azaisoindigo with potential biological activity against SARS-CoV-2. The work was divided into three main parts: the first consisted in synthesizing new acetylated and disubstituted compounds of 3-hydroxy-bis-oxindoles and isoindigos via coupling methodologies according to the literature. The corresponding isatin derivatives were synthesized by coupling conditions with ZrCl4/EtOH/reflux or with HCl/AcOH/reflux, the use of oxindole and functionalized isatins, obtaining 3-hydroxy-bis-oxindoles as products, which were later dehydrated into isoindigos. The second part, in turn, was the synthesis of azaisoindigos, derived from synthetic methodologies for the coupling between isatin derivatives and 7-azaoxoindole. And finally, the third part encompassed the reduction reactions of isatin and its derivatives with NaBH4. A large part of the substances synthesized in this thesis were submitted to biological tests against SARS-Cov-2 through the assay with Vero E6 cells in a High Content Screening platform, carried out by Professor Dr. Lúcio Freitas Júnior from the Biological Sciences Institute, University of São Paulo (ICB -USP). These compounds were tested with single concentration of 10µM, using chloroquine as control. Preliminary results indicated that 06 compounds (4 isatin derivatives and 2 azaisoindigo derivatives) showed biological activity against this virus, responsible for the transmission and manifestation the symptoms of Covid-19. The results, discussions about these experiments, beyond any characterization of the products obtained from analytical techniques such NMR 1H and 13C, FTIR, HRMS, melting point and biological tests will be taken in the course of this work.

17
  • LAÍS DE NOVAES PIRES
  • Development of analytical methods for multi-element determination in beer samples

     
  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MARCOS DE ALMEIDA BEZERRA
  • FABIO DE SOUZA DIAS
  • LEONARDO SENA GOMES TEIXEIRA
  • FABIO ALAN CARQUEIJA AMORIM
  • JOAQUIM DE ARAÚJO NÓBREGA
  • Data: 20 déc. 2021


  • Afficher le Résumé
  • Beer is an attractive alcoholic beverage because it is light, refreshing and has peculiar sensory characteristics. In the present work, analytical strategies were developed for the determination of inorganic species in beer samples. In the first step, an analytical method was developed for the determination of Cl, Fe and Si in beer samples using the strategies of sequential and simultaneous determination by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) in combination with high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). First, Cl was determined using 600 °C and 1700 °C as the pyrolysis and vaporization temperatures, respectively, using In as a forming agent of the InCl molecule. Then, Si and Fe were simultaneously determined from the same sample aliquot using 2600 °C as the atomization temperature. A solution of Pd/Mg was used as a chemical modifier. The matrix effect was evaluated, and the results indicated that external calibration was possible using aqueous standard solutions. The limit of detection and quantification were, respectively, 0.05 and 0.17 mg L-1 for Cl, 0.08 and 0.26 mg L-1 for Si, and 2.0 and 6.7 μg L-1 for Fe. Recovery tests presented interval between 85 and 120% for the three analytes. The concentration range found in the samples varied between 106 - 277 mg L-1 for Cl, 15 - 37 mg L-1 for Si, and < 20–73 μg L-1 for Fe. In the second step, an evaluation of different elements (Be, Ga, In, Sc and Y) was performed as candidates for internal standards (IS) for the determination of Al, Ba, Co, Cr, Cu, Fe, Mn, Ni, Sr, Zn, Ca, Mg, Na, K in beer samples using microwave-induced plasma optical emission spectrometry (MIP OES). The analytical performance for each potential IS was established based on the limit of detection, limit of quantification, addition and recovery tests and accuracy obtained in the determination of each analyte. In the presence of the recommended IS, the limit of detection varied, in mg L-1, from 0.23 to 4.6 for microelements and between 10 and 620 for the macroelements. The limit of quantification, in mg L-1, was between 0.78 and 15.4 and between 30 and 970 for the microelements and macroelements, respectively. The precision values of the measurements were less than 1.0% for all analytes. The methods developed in this work can be considered easy to apply, generating the minimum amount of residues and presented adequate analytical characteristics, such as: precision, accuracy and sensitivity for the determination of inorganic species in beers using different analytical techniques.

     
2020
Thèses
1
  • LEILANE RODRIGUES SANTOS
  • ANALYTICAL STRATEGIES TO ASSESS TOTAL CONCENTRATION AND ESTIMATE BIOACCESSIBILITY OF ESSENTIAL 
    AND POTENTIALLY TOXIC ELEMENTS IN CASSAVA FACULA.
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • Data: 8 janv. 2020


  • Afficher le Résumé
  • This work aimed to propose analytical strategies to assess the total concentration and estimate the bioaccessible fraction of essential and non-essential elements in samples of cassava derivatives (Manihot esculenta Crantz) using a closed system digestor block and techniques based on inductively coupled plasma, being run in three steps. In the first stage, a factorial design 24 was used to establish an adequate condition for the decomposition of the samples, aiming at determining Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Sr and Zn by optical emission spectrometry with inductively coupled plasma (ICP OES). The factors HNO3 concentration, time, temperature and volume of H2O2 were evaluated, using the dissolved organic carbon (DOC) content as a response, with the following conditions being defined, respectively: 7.0 mol L-1 , 45 min and 180 ° C, without using H2O2. The method was precise (≤ 5%), with limits of quantification (LOQ) that varied, in µg g-1 , from 0.005 for Sr and 11 for Ca. In step 2, instrumental parameters were optimized, in order to minimize spectral interferences and determine As, Cd, Co, Cr, Cu, Mn, Pb, Se and V in starch samples by mass spectrometry by inductively coupled plasma (ICP-MS). The accuracy of the methods by ICP OES and ICP-MS was evaluated with tests of addition and recovery tests in three levels of concentration, in addition to the analysis of SRM 1567a (wheat flour, NIST). The concentration ranges, in μg g-1 , for the analytes in the samples of cassava derivatives by ICP OES were: Ba (<0.32 - 0.60), Ca (<11- 542), Fe (<0, 39 - 111), K (156 - 7362), Mg (9.8 - 533), Na (<3.1 - 98), P (58 - 1774) and Sr (<0.005 - 3.85). By ICP-MS, the concentration ranges obtained in ng g -1 were: As (<12 - 158), Cd (<9 - 47), Co (<17 - 295), Cu (<90 - 1159), Mn (70 - 2523), Pb (<14 - 521), Se (<16 - 215), V (<6 - 106) and Zn (<3208 - 7277). Step 3 aimed to estimate the bioaccessible content of Cu, Fe, Mg and Mn in samples of cassava derivatives by ICP OES. The bioaccessible contents, in µg g-1 , varied from <109 and 385 ± 42 for Mg and 0.59 ± 0.001 and 1.44 ± 0.13 for Mn. For Cu and Fe, the bioaccessible levels were below the LOQ. The method was validated using a mass balance, with the following values being found: 95 ± 8% for Mg and 110 ± 1% for Mn. Based on the recommended daily intake for adults, consumption of 100 g of cassava derivative provides 1.0 - 2.8% of the daily intake of Ca, 3.8 - 2.9% for Cu, 1.2 – 12.4% for Fe, 0.4 - 17.8% for Mg 0.8 - 11.0% for Mn, 1.6 - 18.0% for P, 52.7 - 53.7% for Se and 7.0 - 9.1% for Zn. This work has a significant contribution, whether by proposing a simple and low-cost method for evaluating the elemental composition of cassava starch, bringing new nutritional information and of interest to public health.

2
  • ÍCARO VINÍCIUS SANTANA GOMES
  • STUDY OF NICKEL-BASED CATALYSTS AND LANTANIUM, WITH AND WITHOUT ADDITION OF BARIUM CARBONATE, APPLIED IN DRY METANE REFORM.

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • SORAIA TEIXEIRA BRANDAO
  • CAIO LUIS SANTOS SILVA
  • DENILSON SANTOS COSTA
  • JAIME SOARES BOAVENTURA FILHO
  • Data: 8 janv. 2020


  • Afficher le Résumé
  • In this work, the effects of the addition of barium carbonate to nickel-lanthanum-based (Ni/La2O3) catalysts applied to dry reforming of methane (DRM) were investigated. The catalyst precursors were prepared by the wet impregnation method, with and without addition of 5% BaCO3 by mass of the support. The catalytic precursors were characterized by Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD) and Temperature-Programmed Reduction with hydrogen (TPR-H2). After reduction of catalytic precursors and activation, the catalysts were also characterized by XRD. Temperature-Programmed Surface Reaction (TPSR) analyzes and long-term catalytic tests (18 h at 700 °C) were used to evaluate catalyst activity, selectivity and stability in DRM. To compare coke deposition in catalysts, Temperature-Programmed Oxidation with oxygen (TPO-O2) analyzes were performed after TPSR and long-term catalytic tests. TPSR profiles indicated that the four catalysts are active in DRM; water formation, probably through the RWGS reaction, was observed for all, but with greater intensity for BaCO3-containing catalysts. Long-term catalytic tests showed that the BaCO3-containing catalyst calcined at 800 °C showed CH4 and CO2 conversions comparable to catalysts without this promoter. In addition, by TPO-O2 analysis after long-term catalytic tests, it was observed that BaCO3-containing catalysts had lower carbon deposition. Based on this, it was inferred that the addition of BaCO3 to Ni/La2O3 catalysts can reduce coke deposition on the surface of these catalytic systems, making them more resistant to deactivation.

3
  • AKACIA VICTORIA SILVA DOS SANTOS
  • Study of catalysts obtained from perovskite precursors of Ni, Nb and La applied in the oxidative CO2 reforming of methane.

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • SORAIA TEIXEIRA BRANDAO
  • CAIO LUIS SANTOS SILVA
  • DENILSON SANTOS COSTA
  • ROBERT NEWTON DA SILVA HENRIQUES MAGALHÃES
  • Data: 8 janv. 2020


  • Afficher le Résumé
  • In this work, catalysts obtained from perovskite precursors of nickel, niobium and lanthanum applied in the oxidative CO2 reforming of methane (OCRM) were studied. The LaNiO3 and LaNi0.5Nb0.5O3 perovskites were synthesized by the citrate method and characterized by X-ray diffraction (XRD) and temperature-programmed reduction under H2 atmosphere (TPR-H2). The catalysts obtained after reduction of synthesized precursors were tested in the OCRM, by temperature-programmed surface reaction (TPSR) and long-term catalytic tests. The TPSR were performed by applying two different O2 ratios (CH4:CO2:O2 = 4:2:1 and 4:2:1.5) and spatial velocity of 2.33 mL.min1 .mg-1 . The catalytic tests were carried out at 700 °C, also with two different O2 proportions, applying a spatial velocity of 2.33 mL.min-1 .mg-1 and lasting 18 hours. The XRD and TPR-H2 analyzes showed that, after reducing the precursors LaNiO3 and LaNi0.5Nb0.5O3, the catalysts Ni/La2O3 (LANI10) and Ni/La2O3-LaNbO4 (LANB05) were obtained, respectively. The TPSR graphs indicated that the catalysts studied are active in OCRM. Through long-term catalytic tests, it was concluded that the niobium catalyst shows lower conversion of CH4 and CO2 and lower H2 and CO yield. By using a higher proportion of O2, the catalysts show higher CH4 conversion and H2 yield, lower CO2 conversion and lower coke deposition tendency. LANB05 catalyst showed lower surface coke deposit than the catalyst obtained from LaNiO3 perovskite.

4
  • Geiziane Alves Santos
  • SYNTHESIS OF 3-PYRIDAZINONE AND 2-PYROLIDONE VIA AZAANNULATION OF 3-HYDROXYINDOLES WITH HYDRAZINE
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • MAURICIO MORAES VICTOR
  • LOURENCO LUIS BOTELHO DE SANTANA
  • Data: 13 janv. 2020


  • Afficher le Résumé
  • In this work were developed methodologies, studies and reactivity of new heterocycles with biologic potential. It was employed isatin as starting material, a versatile and attractive N-heterocycle that allows various functionalization such as aldolic reactions against a representative group of ketones. As products was obtained 3-hydroxyindolin-2-ones which are isatin derivatives and have a carbonyl group at position-2 of five membered-ring and a quaternary carbon at 3-position. In addittion, they are structural skeletons found in various pharmacological agents and biologically active alkaloids. From the 3-hydroxy 2-indoles was synthesized, against hydrazine, via aza-anullation [4+2] and under mild conditions pyridazinones, which are five-or six-membered heterocycles with two nitrogen atoms and can be found in various compounds with biological activities. In order to broaden the scope to other sites, from isatin and acrylonitrile were sinthesized new hydroxyindoles called MBH-Morita-Baylis-Hillman adducts, which are nuclei of great interest in the synthetic field due to the atomic economy as well as the ability to generate densely functionalized alkenes of great synthetic utility. In this work, the adducts were synthesized comparatively by classic and optimized methodology and reacted with hydrazine hidrate employing microwave heating. It was observed the formation of pyrrolidinones via aza-anullation [4+1], instead of pyridazinones. Under controlled conditions, pyrrolidinones led to quinolinone derivatives.

5
  • VALMORE HENRIQUE PEREIRA DOS SANTOS SOUSA
  • Isolated endophytic fungi from the leaves of Handroanthus impetiginosus as efficient stereoselective biocatalysts for the production of chiral building blocks.

  • Leader : ELIANE DE OLIVEIRA SILVA
  • MEMBRES DE LA BANQUE :
  • ELIANE DE OLIVEIRA SILVA
  • MAURICIO MORAES VICTOR
  • DOUGLAS FERNANDO RAMBO
  • Data: 14 janv. 2020


  • Afficher le Résumé
  • Recently, great attention has been paid to the enantioselective demonstration of optically pure compounds, using ecological methods, due to the growing demand for modern medicines, food ingredients and agrochemicals. Optically pure alcohols are useful as building blocks for samples of bioactive compounds and can be transformed into other functionalities without racemization. Chemical transformations mediated by whole cells of microorganisms have some advantages over chemical procedures, including low cost, high versatility and chemical chemistry, regal and stereoselective. The aim of this study was to identify new endophytic cepes for use as biocatalysts in the reduction of prochiral ketones to chiral alcohols with high conversion rates (Conv.) And enantiomeric excess (e.e.). Seven lines of endophytic fungi were isolated from the leaves of Handroanthus impetiginosus (Ipê purple) and showed stereoselectivity in the conversion of acetophenone (21) into 1-phenylethanol (21a). Initially, the results show all the reduced strains 21, but in different degrees of conversion e.e. In addition, Talaromyces purpurogenus H4 shows excellent performance with excellent conversion (> 99.9%) and good e.e. (82.8%). T. purpurogenus H4 showed a preference for the formation of (S) -1- phenylethanol, which can be used as a precursor to the exposure of natural aromas. Aiming to increase conversion rates and excess bioreduction value by 21, an optimization study was carried out analyzing the parameters: pH of the medium, reaction time, reaction temperature, co-solvent, amount of substrate and amount of fungus used. The reaction performed under the optimized conditions presented (% Conv.) e (% e.e.) equals 97% and 96%, respectively. The optimized conditions were tested in the biotransformation of 6 (six) acetophenone compounds, among those studied, a 4'-nitro-acetophenone (25) exhibited the highest conversion rates (52.2%) and 4'-methoxy-acetophenone (24) the largest enantiomeric excess (91.0%). A preparative scale reaction was performed only for 21, resulting in an isolated yield of 73% e.e. 96%. These results make T. purpurogenus H4 an interesting candidate in demonstrating these and other chiral precursors.

6
  • MIKHAEL PEREIRA MARQUES VIVAS
  • Method development and validation by UFLC-PDA-FLD for determination of endocrine disruptors in water matrices

  • Leader : GISELE OLIMPIO DA ROCHA
  • MEMBRES DE LA BANQUE :
  • GISELE OLIMPIO DA ROCHA
  • VANIA PALMEIRA CAMPOS
  • ANA CECILIA RIZZATTI DE ALBERGARIA BARBOSA
  • Data: 13 mars 2020


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  • Endocrine disruptors (ED) are species with the potential to affect endocrine system capacity at various levels, acting on steroid biosynthesis and or estrogen receptors (ERα and ERβ), resulting in inhibition, blocking or promoting endocrine system activity. Imbalance of the endocrine system directly affects the reproductive capacity of the species, reports of feminization of the population of bird, fish and mammal species can be found in the literature. In humans these substances can promote early puberty in girls, decrease the quality of semen in men and various health problems such as cancer, diabetes and obesity. In this work a chromatographic method was developed and validated for the determination of the following substances: Bisfenol A (BPA), estriol (E3), estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), 4-n-nonylphenol (4-n-NP), 4-noctylphenol (4-n-OP), 4-t-octilfenol (4-t-OP), dimethylphthalate (DMP), diethylphthalate (DEP), butylbenzylphthalate (BBP), di-butylphthalate (DBP), di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) in different water matrices in an acetonitrile (B) / water (A) system. Was used an ultra fast liquid chromatograph coupled to photodiode and fluorescence array detectors, column Shim-pack XR- Phenyl (100 x 2.0 mm, 2.20 μm) The running time was 16 minutes, with repeatability ranging from 4.8% (BBP) to 11.2% (E1) in the inter-day test for four days, LOD ranged from 2 μg L-¹ (E3) to 294 μg L-¹ BBP, and the linearity between 0.9236 (BPA) and 0.9977 (DEHP).

7
  • TÁCILA OLIVEIRA PINTO DE FREITAS
  • DISTRIBUTION, SOURCES AND ORIGIN OF ELEMENTS RARE LANDS AND OTHER METALS IN MANGUE GROUPS SOILS
    AND ESTUARIAN SEDIMENTS.

  • Leader : VANESSA HATJE
  • MEMBRES DE LA BANQUE :
  • VANESSA HATJE
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MIGUEL JOSÉ MARTINS CAETANO
  • TRISTAN CHARLES ROUSSEAU
  • Data: 3 juin 2020


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  • Mangroves are important coastal systems that act as sinks for
    trace elements, including rare earth elements (REE). However, many hypotheses are
    about factors that control the distribution of REE in estuarine sediments,
    which is an environment with rapid changes in its physical and chemical properties. For this reason,
    REE were measured in estuarine sediments and in six cores of mangrove soils from the
    Jaguaripe River estuary, Northeast, Brazil. Our goal was to evaluate fractionation,
    distribution and possible sources of these elements for this coastal environment. As a result,
    for estuarine surface sediments, the ΣREE And they varied between 202 and 220 mg kg-1
    , and Y between 12 and 15 mg kg-1 . The normalized abundances of the Post Archean Australian Shale (PAAS)
    showed enrichment of light REE (LREE) over heavy (HREE). Among the REE,
    only the LREE showed significant correlation with Al (r = 0.85) and Fe (r = 0.96). The average
    ΣREE for mangrove soils along the salinity gradient ranged from 161 ± 18 mg kg1 (low estuary) to 183 ± 16 mg kg-1 (high estuary), an expected result considering the
    conditions of the study site and the general characteristic of estuaries in removing on a larger scale
    REE dissolved in low salinity regions. ΣREE concentrations were
    constant along the vertical profiles, which indicates minimal diagenetic change along the
    time. The absence of REE correlation between Fe and Mn in soils suggests that these elements
    chemicals may be co-precipitating as metal sulfides in the anoxic soils of the
    mangrove. However, sediment chemistry in estuaries and mangroves involves a number of
    estuarine processes, and for a better understanding of the results obtained here, data
    speciation for sediment and interstitial water geochemistry will be needed to test
    the hypotheses presented.

8
  • ROGER SOUZA DE OLIVEIRA
  • Coordination compounds: a strategy for acting as catalysts in the polymerization of ethylene.

  • Leader : ZENIS NOVAIS DA ROCHA
  • MEMBRES DE LA BANQUE :
  • ZENIS NOVAIS DA ROCHA
  • KLEBER QUEIROZ FERREIRA
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • Data: 26 juin 2020


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  • The polyethylene is currently one of the most used materials by modern society, since it started the so-called “Plastic Age”, early last century. There are various different types of polyethylene, with different properties, that lead to different applications, which makes this material quite versatile. This differentiation basically due to the polyethylene production, considering initiators, catalytic systems and industrial conditions.

    Over time the ethylene polymerization process has undergone several modifications. Early processes using radical species as initiators, requiring high pressures and temperatures, were replaced by coordination compounds, on a catalytic system that made it possible to use much milder reaction conditions and obtaining a better quality polymer.

    The first catalytic system of great success in industrial scale, they were Ziegler-Natta’s catalysts, made in the 50’s. With them it was possible get high density polyethylenes, with linear chain, without ramification as obtained with radical initiators. From knowledge obtained from this system obtained from this system, uniting coordination compounds containing transition metals and organometallic compounds, mainly alkylaluminiuns, it was possible develop various new catalyst called metalocenes.

    In this job were used a series of catalysts, as the zirconocene (ZDC) which contains zirconium as a metal center, and a series of catalysts type 2,6-bis(imino)pyridine (MIpy), which contains iron or cobalt in its coordination realm. The catalysts were used singly or in combination and in all cases was utilized methylaluminoxane (MAO), to generate the catalytically active species to act on polymerization.

    Further of homogeneous catalysis, the system with the heterogenation of the catalysts was used, using a carrier, changing the polyethylene’s properties. The carrier used was reduced graphene, a allotropic form of carbon, recently discovered. It stands out due to its excellent electrical and thermal properties, fact that considerably changes polyethylene, getting a product with increasingly comprehensive applications.

9
  • FÁBIO XAVIER ANTUNES SAMPAIO
  • Optimization of an analytical methodology for the sulfur markers determination in petroleum by GC-MS/MS.

  • Leader : MARIA ELISABETE MACHADO
  • MEMBRES DE LA BANQUE :
  • GABRIELA PEREIRA DA SILVA MACIEL
  • KARINA SANTOS GARCIA
  • MARIA ELISABETE MACHADO
  • VANIA PALMEIRA CAMPOS
  • Data: 26 août 2020


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  • Dibenzothiophene (DBT), benzothiophene (BT) and their alkylated homologous are important sulfur organic compounds (OSC) present in low concentrations in petroleum. The occurrence and distribution of these OSC in crude oils are used as markers of maturity, biodegradation and depositional environment. Traditionally, the characterization of crude oils involves several stages of sample preparation based on the separation by groups according to the polarity of the compounds and subsequent analysis of the fractions separated by GC-MS. The aim of the present study was to employ gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) for the determination and quantification of OSC markers (classes BT, DBT and naphthobenzothiophene) in crude oil samples. Initially, a GC-MS/MS method was optimized using a mix containing fourteen OSC standards in full scan mode (SCAN) to obtain the mass spectrum, retention time of each compound and observe the separation between them. Optimization was also carried out for the selective ion monitoring mode (SIM) and in the multiple reaction monitoring mode (MRM) to define the collision cell energy used in this operational mode. The optimized method was initially applied to an oil sample, with no previous fractionation stage, in a qualitative way in a comparative study, based on selectivity and signal intensity in order to verify the effectiveness of the MRM method compared to the SIM mode. The results of the SIM and MRM modes indicate that the GC-MS/MS approach in the MRM mode achieved greater specificity and sensitivity for determining CSO. The MRM method was then applied to quantify eight samples of crude oil from the Potiguar Basin without fractionation steps. Finally, diagnostic reasons, based on sulfur markers such as: DBT / Phen; 4- / 1-MDBT; 2.4-/1.4 DMDBT; 4,6-/1,4-DMDBT; 1-MDBT/DBT were calculated and interpreted. It was concluded that the optimized GC-MS / MS method in MRM mode eliminated the need for fractionation and was efficient for the quantification of OSC markers and represents an analytical advance in the area of sulfur markers in oil samples. In addition, it made it possible to evaluate, through diagnostic reasons, together with other parameters, the degree of maturity, biodegradation and depositional environment in oil samples from the Potiguar Basin.

10
  • FILIPE BARBOSA SANTANA
  • DEVELOPMENT OF ANALYTICAL METHODS FOR QUANTIFICATION OF THE TOTAL MINERALS CONTENT IN RAW AND COOKED FORAGE PALMS OF THE STATE OF BAHIA

  • Leader : DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • LAÍS ARAÚJO SOUZA
  • LETÍCIA MALTA COSTA
  • RODOLFO DE MELO MAGALHAES SANTANA
  • Data: 11 sept. 2020


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  • The forage palm (Opuntia ficus-indica and Nopalea cochenilifera) has been one of the most cultivated cacti in the northeast region of Brazil because it remains resistant throughout the dry period, serving both for animal and human food. Despite being widely cultivated in northeastern Brazil, there is still a lack of information regarding its mineral composition. Thus, this work aims to propose analytical strategies to determine the total content of As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Na, P, Pb, Sr and Zn in palm leaves raw and cooked using different sample preparation procedures and determination by inductively coupled plasma optical emission spectrometry (ICP OES). The samples were collected in different cities in the state of Bahia (11) and one in the city of Serra Talhada (Pernambuco) for comparison between the different states. To assess the total content, the following procedures were proposed: i) acid decomposition in a digestor block with a closed system; ii) ultrasound assisted extraction. In the optimization of both procedures, a complete factorial design was used and the heavy mass was about 0.5 grams. The optimal condition for acid decomposition was: HNO3 (5.0 mol L-1) addition of 2.0 mL of H2O2 (30% m m-1) for 2 hours at 180 °C. For the extraction procedure, the optimal condition was 10 mL of HNO3 (1.5 mol L-1) sonicated for 7 minutes and 30 seconds. The accuracy for the procedure (i) was verified using certified reference material (CRM Agro C1003a – Tomato leaves and CRM NIST 1547 - Peach leaves) and addition and recovery tests and, for procedure (ii) with CRM Agro C1003a, CRM NIST 1573a - Tomato leaf and CRM Agro FC_012017 - Sugar cane leaf and comparison with procedure (i). In both procedures, the recovery percentages varied between 80 and 120%. The precision for both procedures was assessed based on the relative standard deviation (%), n = 10, being less than or equal to 7.0% for all analytes. After applying procedures (i) and (ii) to the 12 samples, it was observed that the highest concentrations were for Ca, followed by K, Mg and P. The lowest concentrations were observed for the Cu microelement, followed by Fe, Zn, Ba and Mr. Vale point out that for procedure (ii) there were no good extraction percentages for Ca and Fe. Analyzes As, Cd, Co, Cr, Na and Pb were below the limit of quantification, in all samples, in two proposed procedures. Statistical tools such as principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied and a similarity trend was observed between the samples with a small dispersion among the studied varieties. The influence of the cooking process on the concentration of the elements present in the palm leaves was also verified. It was observed that the changes in the concentration of the elements are smaller in the microwave when compared to the stove. The evaluation of the recommended daily intake (RDI) showed that regular intake of 50 g of raw or cooked palm has a good contribution to the intake of essential elements such as Ca, Cu, Fe, K, Mg, P and Zn, being the highest contributions, in %, to Ca (44-240), Mg (89-236) and Zn (8,8-75).

11
  • TAIANA ANDRADE DA ANUNCIAÇÃO
  • MULTIELEMENTARY DETERMINATION IN ENTERED NUTRITIONAL FORMULAS BY OPTICAL EMISSION SPECTROMETRY WITH INDUCTIVELY COUPLED PLASMA USING SUSPENDED SAMPLING.

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • Data: 16 oct. 2020


  • Afficher le Résumé
  • An adequate nutritional dietary and an efficient absorption of nutrients by the human body are fundamental factors for its functioning. However, for some hospitalized patients, the ingestion and absorption of food is difficult, requiring the use of nutritional techniques, such as enteral nutrition therapy. Most of these nutritional formulas contains vitamins and minerals, requiring strict administration of these nutrients in order to prevent harm to patients. Thus, a quality control of these products is important, which includes the determination of inorganic species. In this work, an analytical strategy for the determination of Cu, Fe, K, P and Zn was developed by inductively coupled plasma optical emission spectrometry (ICP OES) in enteral nutritional formulas using slurry sampling. To determine the best experimental conditions, in relation to the use of suspension stabilizing reagents (HNO3, ethanol and Triton X-100), a factorial experimental design 23 was carried out. The intensity of the signals obtained in the ICP OES was established as a dependent parameter for each analyte (as multiple response) and as independent variables the concentrations of stabilizing reagents used in the preparation of suspensions. The experimental domain involved maximum values of HNO3, ethanol and Triton X-100 concentration in 10%, 6.0% and 0.5% v v-1, respectively, and minimum values of 0%. The suspensions were prepared in an environment containing the stabilizing agents and 0.20 g of the sample to a final volume of 20.0 mL, followed by manual stirring. It was found that none of the tested reagents had a significant influence on the intensity of the signals obtained in the experimental domain studied, indicating that the sample could be analyzed directly, after simple dilution. However, in the recommended procedure, the use of 10% v v-1 HNO3 was indicated for better extraction of the analytes from the matrix. Under the conditions indicated, it was possible to observe the matrix effect, in such a way that the construction of the calibration curves was done in the presence of the sample using curves with the addition of analytes. The method allowed the determination of Cu, Fe, Zn, K and P in enteral nutritional formulas with detection limits in the order of mg L-1 (0.005; 0.009; 0.011; 24.0; 8.0, respectively). Addition and recovery tests in enteral nutritional formulas were performed with results between 96 and 120%. The proposed method was applied to analyze enteral nutritional formulas by slurry sampling. The results were compared with those obtained after digestion of samples in a microwave oven and no significant differences were observed. The concentration ranges found in the samples analyzed, in mg L-1, were: Cu (0.41 - 0.5), Fe (2.0 - 3.1), Zn (1.7 - 4.7), K (682 - 1409) and P (217 - 344). The work has great integrated academic value, since it is the first work registered in the literature that proposed an alternative for determining Cu, Fe, K, P and Zn present on the label of enteral nutrition formulas.

12
  • TAIANA ANDRADE DA ANUNCIAÇÃO
  • MULTIELEMENTARY DETERMINATION IN ENTERED NUTRITIONAL FORMULAS BY OPTICAL EMISSION SPECTROMETRY WITH INDUCTIVELY COUPLED PLASMA USING SUSPENDED SAMPLING.

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • LEONARDO SENA GOMES TEIXEIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • Data: 16 oct. 2020


  • Afficher le Résumé
  • An adequate nutritional dietary and an efficient absorption of nutrients by the human body are fundamental factors for its functioning. However, for some hospitalized patients, the ingestion and absorption of food is difficult, requiring the use of nutritional techniques, such as enteral nutrition therapy. Most of these nutritional formulas contains vitamins and minerals, requiring strict administration of these nutrients in order to prevent harm to patients. Thus, a quality control of these products is important, which includes the determination of inorganic species. In this work, an analytical strategy for the determination of Cu, Fe, K, P and Zn was developed by inductively coupled plasma optical emission spectrometry (ICP OES) in enteral nutritional formulas using slurry sampling. To determine the best experimental conditions, in relation to the use of suspension stabilizing reagents (HNO3, ethanol and Triton X-100), a factorial experimental design 23 was carried out. The intensity of the signals obtained in the ICP OES was established as a dependent parameter for each analyte (as multiple response) and as independent variables the concentrations of stabilizing reagents used in the preparation of suspensions. The experimental domain involved maximum values of HNO3, ethanol and Triton X-100 concentration in 10%, 6.0% and 0.5% v v-1, respectively, and minimum values of 0%. The suspensions were prepared in an environment containing the stabilizing agents and 0.20 g of the sample to a final volume of 20.0 mL, followed by manual stirring. It was found that none of the tested reagents had a significant influence on the intensity of the signals obtained in the experimental domain studied, indicating that the sample could be analyzed directly, after simple dilution. However, in the recommended procedure, the use of 10% v v-1 HNO3 was indicated for better extraction of the analytes from the matrix. Under the conditions indicated, it was possible to observe the matrix effect, in such a way that the construction of the calibration curves was done in the presence of the sample using curves with the addition of analytes. The method allowed the determination of Cu, Fe, Zn, K and P in enteral nutritional formulas with detection limits in the order of mg L-1 (0.005; 0.009; 0.011; 24.0; 8.0, respectively). Addition and recovery tests in enteral nutritional formulas were performed with results between 96 and 120%. The proposed method was applied to analyze enteral nutritional formulas by slurry sampling. The results were compared with those obtained after digestion of samples in a microwave oven and no significant differences were observed. The concentration ranges found in the samples analyzed, in mg L-1, were: Cu (0.41 - 0.5), Fe (2.0 - 3.1), Zn (1.7 - 4.7), K (682 - 1409) and P (217 - 344). The work has great integrated academic value, since it is the first work registered in the literature that proposed an alternative for determining Cu, Fe, K, P and Zn present on the label of enteral nutrition formulas.

13
  • DANILO KLEBER SANTOS SALES
  • Synthesis, characterization and reactivity of ruthenium (II) indazole complex: potential anticancer agent
  • Leader : LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MEMBRES DE LA BANQUE :
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • KLEBER QUEIROZ FERREIRA
  • CARLOS DANIEL SILVA DA SILVA
  • DENISE SANTOS DE SA
  • Data: 23 oct. 2020


  • Afficher le Résumé
  • Ru(II)-based complexes have been widely reported in literature as a class of compounds that have anticancer activity, due to its interaction with cellular structures, which results in the death of tumor cells. In this work, novel complex cis-[RuII(1H-indazole)2(2,2-bipyridine)2](PF6)2 was synthesized. Characterization by elemental analysis, spectroscopy and electrochemistry validated the formulation of complex. Density functional theory (DFT) study provided insight into the composition of molecular orbitals of the ground state in gaseous phase, and time-dependent DFT (TD-DFT) results elucidated the nature of eletronic transitions absorption in acetonitrile, indicating λmax=445 nm is assigned to metal-ligandbipyridine charge transfer (MLCT). The complex can act as Brønsted-Lowry acid against bases and protonated specimen are predominant in physiological. Photosubstitution reaction occurred when blue LED was irradiated in acetonitrile solution, indicating that compound is photosensitizer.  In vitro anticancer studies revealed that the complex is cytotoxic against hepatocellular carcinoma (HepG2), with the half maximal inhibitory concentration (IC50) equivalent to 7.2 µmol L-1, inducing mainly DNA fragmentation, which resulted in arrest of S phase and HepG2 cell death by apoptosis. Against healthy human pulmonary fibroblast cells (MRC-5), the compound healthy revealed non-cytotoxicity, exhibiting high selectivity. The results obtained indicated that the complex has potential to be used in live-cancer treatment, which will be supported by further studies.

14
  • RAFAEL FRANCO DE JESUS
  • EMPLOYMENT OF POLYMERS WITH PRINTED IONS FOR PRE-CONCENTRATION AND DETERMINATION OF CADMIO AND LEAD

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • WALTER NEI LOPES DOS SANTOS
  • KARINA SANTOS GARCIA
  • Data: 16 nov. 2020


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  • Wine and beer are alcoholic beverages widely consumed in Brazil and worldwide. Due to their popularity it is important to know their composition, especially the determination of potentially toxic metals. In this perspective, analytical strategies aimed at determining contaminants in these matrices are opportune. In this work, two polymers with printed ions (IIP) were synthesized and used in a pre-concentration system to determine cadmium and lead in samples of alcoholic beverages. The synthesized IIPs contained the impression of Cd (II) and Pb (II) ions, where the "bulk" polymerization process was employed. These sorbents were used in a pre-concentration column and the metals were detected by flame atomic absorption spectrometry (FAAS). The optimal conditions of use of the column were obtained through multivariate techniques of experimental designs. The system allows the determination with detection and quantification limits of 1.0 and 3.5 µg L-1 for cadmium and 23.5 and 80.0 µg L-1 for lead, respectively. The linearity observed for cadmium was 3.5 to 500 µg L-1 and for lead 5.4 to 2000 µg L-1, with correlation coefficients (R²) of 0.9980 and 0.99991 for cadmium and lead, respectively. The proposed procedure was applied to determine cadmium and lead in samples of wines and beers.

     

15
  • ÍCARO SACRAMENTO DE ALMEIDA PORTO
  • ANALYTICAL STRATEGIES USING DIGITAL IMAGES FOR DETERMINATION OF ASCORBIC ACID IN FRUIT JUICES

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • VALFREDO AZEVEDO LEMOS
  • RITA MARIA WESTE NANO CARVALHO
  • Data: 11 déc. 2020


  • Afficher le Résumé
  • In recent years, several spectrophotometric methods consolidated in the literature have been adapted for digital images (DI), offering an alternative for fast, portable and low-cost analysis. In this context, the present work proposed the development of analytical strategies based on digital images for quantification of ascorbic acid in samples of natural fruit juices using the chromogenic reagents 1,10-phenatroline and Br-PADAP (- (5-bromo-2- pyridylazo) -5-diethylaminophenol). In an acidic environment, ascorbic acid reduces Fe (III) to Fe (II) and this new oxidation state forms colored complexes with the proposed reagents. To establish the best analysis conditions, multivariate and univariate optimization techniques were applied. The images were obtained through a webcam coupled with a CMOS detector (Complementary Metal-Oxide Semiconductor) and stored in .jpg format and submitted to specific software for data extraction. The construction of the analytical signal was performed using the additive model of RGB colors corresponding to the colors red, green and blue. Two forms of processing were investigated: one is analogous to Beer's law and the other was defined as the result of the expression: S = 255 - (R, G or B), where R, G or B, refers to intensity of radiation emitted by the standard or sample solution in a color component. The precision of the method was assessed in terms of relative standard deviation (% RSD) using samples chosen arbitrarily (n = 10), with values ranging between 1.2% and 8.2%. The limits of detection (LD) varied between 0.004 and 0.857 mg/100g and those of quantification (LQ) between 0.012 and 2.857 mg/100g. Accuracy is assessed using the results of the corresponding molecular technique. The ascorbic acid concentrations in a total of 13 fruit samples were evaluated, namely: lemon, orange, grape, lime, pineapple, tangerine, mango, mangosteen, plum, passion fruit, genipap, melon and watermelon, purchased in the city of Salvador. The concentrations obtained varied between 3.8 mg/100g and 38.1 mg/100g. The analysis of digital images produced satisfactory results and proved to be a promising alternative to replace the use of expensive equipment.

     

     

16
  • Renata Soares Teixeira
  • Quantum dots immobilization into agarose discs for water analysis devices development.

  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MARIA DAS GRACAS ANDRADE KORN
  • ARTUR JOSE SANTOS MASCARENHAS
  • RODOLFO DE MELO MAGALHAES SANTANA
  • MARCO TADEU GRASSI
  • Data: 14 déc. 2020


  • Afficher le Résumé
  • Quantum dots (QD) are widely used as luminescent probes due to the high quantum yield, high photostability and narrow emission bands. However, the potential toxicity associated to metallic species and radical species photo-generation, raise questions about their application as probes for in situ analysis of water. Therefore, different strategies were evaluated for QD immobilization into agarose films aiming to the development of devices for in situ analysis of metals in waters based on the diffusion gradient in thin films. Thus, CdTe capped with glutathione (GSH-CdTe) and carbon (CQD; N-CQD) quantum dots were synthesized by hydrothermal and pyrolysis approaches, respectively. Solid supports such as aminated glass beads (SiO2-NH2), silica (SiO2) and polymers (aminopropyltriethoxysilane - APTES) were studied for luminescent composite synthesis. The synthesized QD composites were tested on thin agarose gel discs (h = 1.6 mm; Φ = 2.0 cm) and immersed in purified water for periods of up to 24 h. The fluorescent intensity of thin QD/agarose discs and their diffusion into water was monitored by molecular fluorescence spectroscopy and image analysis. The QD direct addition to agarose films led to probe diffusion with visible increase water luminescence after 30 min of immersion. In addition, contamination of water samples by N-CQD@APTES was observed with an emission decay of 70% in 24 h. For QDs linked to substrates by covalent bonding (GSH-CdTe @ APTES) migration to water was not observed and a low variation in fluorescence was observed (<20%), except for the CQD@SiO2 and GSH-CdTe@SiO2-NH2 composites, whose fluorescence decay levels were superior to 90%. Finally, the response of thin agarose discs doped with GSH-CdTe@APTES against Hg2+, Cd2+, Pb2+ and Cr3+ (50 μg L-1) were observed (ΔF≥90%).

Thèses
1
  • DALILA DOS SANTOS MONTEIRO
  •   Carbon Nitride: Polymeric semiconductor applied to photocatalytic production of hydrogen.

  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • LUCIANA ALMEIDA DA SILVA
  • MAURICIO MORAES VICTOR
  • RAILDO ALVES FIUZA JUNIOR
  • ARNAUD VICTOR DOS SANTOS
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • Data: 7 févr. 2020


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  •   

    In the present work, the synthesis, characterization and photoactivity of polymeric carbon nitride (PCN) based semiconductors were evaluated in the photocatalytic hydrogen production under visible light irradiation (ʎ ≥ 420 nm), employing glycerol and the ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) as sacrificial reagents. The synthesis of the photocatalysts was performed by thermal polycondensation method and some synthesis parameters were investigated, such as precursor type, heating rate and heat treatment time. The thermal decomposition process of the synthesis precursors was investigated by TG and DSC analyses. The characterization of the photocatalysts was performed several by techniques, such as TG, DSC, XRD, FTIR-ATR, Raman, SEM, N2 Physisorption, DRS, PL, and zero point of charge (pHzpc). Photocatalytic reaction parameters such as pH (4.0, 7.0 and 9.0) and sacrificial reagent type (glycerol and EDTA) were also investigated. The techniques used to characterize the synthesized materials allowed us to identify that the solids obtained from thiourea have structural, morphological, textural and optical properties that favor the higher photoactivity of these materials. The photocatalytic reaction parameters that presented the best photocatalytic performance were at pH = 7.0 with EDTA as a sacrificial reagent. The synthesis condition capable of obtaining the material that achieved the best performance in photocatalytic hydrogen production was thiourea as a precursor, due to bandgap narrowing and charge recombination suppression; the heating rate of 5 °C min-1 and a heat treatment time of 6 h produced the most crystalline material. The combination of these effects led the sulfur-doped polymeric carbon nitride sample (sample named SCN4) to a higher photocatalytic activity, reaching a hydrogen production rate of 214.75 μmol g-1 h -1 .

2
  • HYRLAM SOUSA FERREIRA
  • Analytical strategies for assessing mineral composition and estimate of the bioaccessibility of 
    essential elements and potentially toxic in tobacco products (Nicotiana tabacum L.)
  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • LEONARDO SENA GOMES TEIXEIRA
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • SARAH ADRIANA ROCHA SOARES
  • Data: 6 mars 2020


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  • In this work, analytical methods were developed to determine inorganic constituents in tobacco products samples (cigar, shredded smoke and rope smoke), using inductively coupled plasma-optical emission spectrometry (ICP OES). The operating conditions of spectrometer were optimized by applying Doehlert design. A Box-Behnken design was used to determine the optimal conditions for sample digestion process using closed digestor block. The limits of quantification (LQ) varied between 0.09 μg g-1 (Ba and Ti) and 116 μg g−1 (Na). The analytical method was applied to determine nineteen chemical elements (Al, As, Ba, Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Sr, Ti, V and Zn) in tobacco products. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to assess the different types of tobacco products, considering the elemental composition. A method was also developed to determine inorganic constituents in samples of tobacco products by ICP OES, after ultrasound-assisted extraction. Box-Behnken design and the desirability function were used for optimize the procedure for extracting analytes. After optimized experimental conditions, the analytical method allowed the determination of Ba, Ca, K, Mg, Mn, Na, P and Sr, with limits of detection of 0.0007, 4.6, 115, 2.3, 0.08, 14, 7.2 and 0.03 µg g-1 , respectively. The accuracy of the analytical methods was confirmed by analysis of the certified reference material (CRM) of oriental tobacco leaves (CTA-OTL-1), apple leaves (NIST 1515) and tomato leaves (CRM-Agro C 1003a). The bioaccessibility estimate of Al, Ca, Cd, Cu, Fe, K, Na, P, Ti, V and Zn in rope smoke was performed using in vitro extraction method for Simple Bioaccessibility Extraction Test (SBET). The bioaccessible fractions obtained in percentage were: 4.06 - 7.8 (Al);

3
  • IVANA LAGO DA SILVA ROMÃO
  • Strategies for characterizing the chemical composition of casearia fasciculata (glass fruit) using analytical techniques

     

  • Leader : ANA MARIA PINTO DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ANA MARIA PINTO DOS SANTOS
  • VALFREDO AZEVEDO LEMOS
  • AMALIA GEIZA GAMA PESSOA
  • CLEBER GALVAO NOVAES
  • DÉBORA DE ANDRADE SANTANA
  • FABIO ALAN CARQUEIJA AMORIM
  • Data: 8 juil. 2020


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  • In this thesis the characterization of Casearia fasciculata (Fruta Vidro) is presented through the study of the chemical composition of the fruit, the aerial parts and the application of the root as a biosorbent. A digestion method using diluted nitric acid was optimized by planning the mixture for simultaneous extraction of 10 elements in pulp, bark and seed of Casearia fasciculata grown in the state of Bahia, Brazil. Four different approaches were used to assess the performance of the digestion procedure (Multiple Response; Desirability; Residual carbon content and Residual acidity). The multivariate tools, PCA and HCA, were efficient in forming groups, corresponding to the parts of the fruit. The root potential of the Casearia fasciculata plant for extracting Mn (II) in aqueous systems was evaluated in a pre-concentration system using a minicolumn filled with the biosorbent. The system was optimized through the application of 24-1 fractional factorial design and Doehlert matrix. The biosorbent also showed potential for the remediation of Cd (II), Ni (II) and Pb (II) ions in aqueous medium. The essential oil from the aerial parts of Casearia fasciculata was extracted by hydrodistillation and its major chemical components identified by CG-EM. The results showed that the oil composed mainly of β- Elemeno, (Trans) -βKaryophylene, Germacrene-D, Bicyclogermacrene and α - Bulnesene were identified by CG-EM. The oil has also been shown to be an efficient tick-killing agent against Rhipicephalus.microplus. The glass fruit (peel and seed) has potential for use as mineral supplements in human nutrition, as well as the root and aerial parts presents an excellent prospect for use as a biosorbent and tick. The flow system, associated with the FAAS technique, allowed a quick analysis, easy operation, efficient and sensitive for the species. The results proved that this plant has potential for application in promising biological activities

4
  • GIULYANE FELIX DE OLIVEIRA
  • OBTAINING FURFURAL AND ALCOHOL PRODUCTION FURFURILIC: ALTERNATIVES FOR VALORIZING 
    THE BABAÇU PECÍOLO.
  • Leader : HELOYSA MARTINS CARVALHO ANDRADE
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • HELOYSA MARTINS CARVALHO ANDRADE
  • LUCIANA ALMEIDA DA SILVA
  • VALERIA CRISTINA FERNANDES
  • CARINE TONDO ALVES
  • RENAN TAVARES FIGUEIREDO
  • Data: 21 juil. 2020


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  • The production of value-added chemicals and residues valorization are promoted by the Green Chemistry and Circular Economy concepts. Based on these principles, this work was undertaken to use and valorize the petiole of the babassu leaf (Orbignya phalerata), a lignocellulosic biomass residue, inedible, abundant and available in South America. Thus, the study aimed to contribute to the sustainability of the furfural production chain, which has economic, social and environmental impact. The use of babassu petiole, a waste which is naturally discarded by the palm tree, was initially evaluated to produce furfural, through the reactive distillation method. The method consisted of reactive distillation of the biomass residue, using different acid catalysts (H2SO4, H-ZSM-5 and the solid carbonaceous residue of the H2SO4 catalyzed distillation).The obtained furfural yields were 45%, and the turnover number of 15.9 was achieved over the solid residue resulting of the homogeneous reactive distillation. This carbonaceous residue was also used as a starting material to produce activated carbons for the removal of volatile organic compounds (VOCs) from industrial and domestic environments. The activated carbons, obtained by pyrolysis at 600-800°C of the carbonaceous residue of the reactive distillation, showed an adsorption capacity of 212 mg g-1 , high stability and selectivity to polar VOCs, specially to the organochlorine compounds, such as chloroform and dichloromethane. After 10 cycles of adsorption, the reduction of the dichloromethane removal capacity was 4%, over the activated carbon obtained at 800°C. About 62% of the world's production of furfuraldehyde is converted to furfuryl alcohol by hydrogenation reaction in liquid or vapor phase and the demand is still increasing. Herein, hydrogenation of furfural was also carried out in vapor phase using different Cu-Mg-Cr catalysts. The catalysts were prepared by the combustion method, which is a simple and economical method, and characterized by different techniques. Reaction conditions were optimized and furfural conversions higher than 80%, furfuryl alcohol yields higher than 60% were achieved, and selectivity greater than 89%, over the Cu0.50Mg0.50Cr2O4 and Cu0.75Mg0.25Cr2O4 catalysts. The selected catalyst was recycled and showed high stability (88%) after 3 reaction cycles. The results show that Cu (I) is stabilized by segregated chromium oxide, such as CuCrO2 (McConnellite), and that the hydrogenation yield is related to the dispersion and metallic area of copper on chromium oxides (Cr2O3) and chromium oxides and magnesium (MgCr2O4).

5
  • CAIO SILVA ASSIS FELIX
  • SYNTHESIS, CHARACTERIZATION AND APPLICATION OF POLYMERS WITH IONS PRINTED FOR QUANTIFICATION 
    OF METALS IN ENVIRONMENTAL SAMPLES.
  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • LEONARDO SENA GOMES TEIXEIRA
  • VALFREDO AZEVEDO LEMOS
  • ICARO THIAGO ANDRADE MOREIRA
  • KARINA SANTOS GARCIA
  • Data: 30 juil. 2020


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  • In this work, three new polymers with printed ions (IIP) were synthesized, characterized, optimized and used in pre-concentration systems for the determination of metals in water samples. The IIPs with Bi (III), Cr (III) and U (VI) ions were all synthesized using bulk polymerization and later characterized, with the exception of IIP-U (VI), using infrared spectrometry with Fourier transform (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The materials obtained were used as sorbents in mini-columns, for use in line and batch systems for detection by different spectrometric techniques. One of the systems developed was the IIP-Bi (III). This was applied to an in-line preconcentration system coupled to a hydride generation atomic fluorescence spectrometer (GH-AFS), which initially studied factors that directly influence the ion quantification conditions. In this work, a detection and quantification limit of 26 and 88 ngL-1 was observed, respectively, and a pre-concentration factor of 19.8. The Bi (III) concentrations found in seawater samples ranged from 0.38 ± 0.01 to 0.45 ± 0.01 μg L-1. Another online system was applied to IIP-Cr (III), for determination by flame atomic absorption spectrometry (FAAS) in tap water samples. In summary, a pre-concentration factor of 14, quantification and detection limits of 0.148 mgL-1 and 0.044 mgL-1 were observed. The Cr (III) concentrations found in tap water samples ranged from 0.33 ±0.01 to 0.42 ± 0.01 mgL-1. Finally, a methodology using an IIP-U (VI) as a sorbent was proposed, applying to the method an alternative form of detection, using digital image. The method had detection and quantification limits of 2.55 and 8.51 μg L-1 respectively, and a preconcentration factor of 8.2. Water samples from lakes surrounding the city of Caetité-Ba were analyzed and presented concentrations ranging from 20 to 75 μg L-1.

6
  • DAYARA VIRGÍNIA LINO ÁVILA
  • Determination of the total concentration and bioavailable fractions of inorganic constituents in modeling clay samples, gouache / tempera paints and plastic toys using chemometric tools and atomic spectrometry

  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • AMALIA GEIZA GAMA PESSOA
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • VICTOR CERDÀ MARTÍN
  • EDUARDO SIDINEI CHAVES
  • LETÍCIA MALTA COSTA
  • Data: 31 juil. 2020


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  • Three works were developed as analytical strategies for toy analysis, with the purpose of determining inorganic constituents in modeling clay, gouache / tempering paints and plastic toys samples, in addition to determining the bioavailable fraction of the chemical elements in this toys employing atomic spectrometry. In the first work, experimental design were applied to optimise the conditions of microwave-assisted sample digestion by analysis of toy samples. Methods based on inductively coupled plasma (ICP) were used to determine the concentrations of 22 elements in children's modeling clay. The limits of quantification (LoQ) obtained varied between 0.30 mg kg-1 (Cu) and 0.54 g kg-1 (Ca) using inductively coupled plasma optical emission spectrometry (ICP OES) and between 0.003 mg kg-1 ( Cd, Co, S and V) and 0.26 mg kg-1 (Se) by inductively coupled plasma mass spectrometry (ICP-MS). The evaluation of the reliability of the method was confirmed through by analysis of certified reference materials of oyster tissue (NIST 1566b), rice flour (NIST 1568b), peach leaves (NIST 1547) and tomato leaves (NIST1573a), as well as applying addition and recovery tests at five concentration levels. The concentrations obtained varied between <1.9 and 55.18 ± 2.38 mg kg-1 (Ba), <0.54 and 0.93 ± 0.24 g kg-1 (Ca), <0.30 and 94.95 ± 3.62 mg kg-1 (Cu), <0.14 and 13.48 ± 0.07 g kg-1 (K), <0.003 and 15.24 ± 0.44 g kg-1 ( Mg), <0.03 and 19.23 ± 1.17 g kg-1 (Na), <0.030 and 1.97 ± 0.06 g kg-1 (P), <0.10 and 8.22 ± 0.31 g kg-1 (S), <133 mg kg-1 and 11.04 ± 3.00 g kg-1 (Al) and <0.53 mg kg-1 and 1.59 ± 0.30 g kg-1 (Fe), for elements determined by ICP OES and between <0.005 and 3.35 ± 0.75 mg kg-1 (V), <0.03 and 9.33 ± 0.65 mg kg- 1 (Cr), <0.03 and 0.650 ± 0.113 mg kg-1 (Co), <0.03 and 19.06 ± 4.92 mg kg-1 (Ni), <0.18 and 28.62 ± 3.64 mg kg-1 (Zn), <0.03 and 1.06 ± 0.21 mg kg-1 (As), <0.25 and 383.73 ± 18.89 mg kg-1 (Mn) , <0.26 and 0.53 ± 0.04 mg kg-1 (Se), 0.91 ± 0.38 and 334.17 ± 37.52 mg kg-1 (Sr), <0.003 and 0.32 ± 0.06 mg kg-1 (Cd), <0.003 and 0.06 ± 0.02 mg kg-1 (Sb) and from <0.010 and 7.55 ± 0.86 mg kg-1 (Pb), for the chemical elements determined by ICP-MS. In the second work, the determination of the total concentrations and bioavailable fractions of As and Sb in gouache / tempering children's paints samples type was carried out using the analysis by injection in multi-syringe flow coupled to hydride generation atomic fluorescence spectrometry (MSFIA- HG-AFS). For As and Sb determinations, NaBH4, KI and HCl concentrations were evaluated as factors. The optimization was performed through the Doehlert design, with the intensities of total As and Sb as multiple response. The LoQ were 14.38 ng g-1 for As and 8.56 ng g-1 for Sb. For the determination of bioavailable concentrations, the LoQ were 16.21 ng g-1 for As and 7.08 ng g-1 for Sb. The precision and accuracy of the analytical method was confirmed through by analysis of certified reference materials of clay (CRM 052, Loamy Clay 1, Sigma Aldrich, USA), and river water (River Water, SLRS-4, National Research Council, Canada) and through addition and recovery tests. The analytical method was applied to twenty samples of gouache / tempering paints, in which As concentrations varied between <LoQ (<14 ng g-1) and 136.0 ± 1.1 ng g-1, and the concentrations of Sb varied between <LoQ (<8.6 ng g-1) and 74.0 ± 5.4 ng g-1. For the determination of bioavailable fractions, the procedure was applied to eight paint samples, in which for all samples the concentrations of As (<16.2 ng g-1) and Sb (<7.1 ng g-1) were below than LoQ. Finally, in the third work, a Doehlert design was employed to optimize the conditions by microwave-assisted digeston of the plastic toy samples for determination of of As, Cd, Co, Cr, Cu, Mn, Ni Pb and Sb by ICP OES and MSFIA-HG-AFS. The procedure was validated through by analysis of CRM clay (CRM 052, Loamy clay) and through addition and recovery tests. The LoQ varied between 0.03 mg kg-1 (Cd and Mn) and 0.7 mg kg-1 (Sb). The concentrations found varied between <LoQ (0.3 mg kg-1) for As; 0.21 ± 0.01 and 0.71 ± 0.04 mg kg-1 for Cd; 0.15 ± 0.02 and 1.16 ± 0.02 mg kg-1 for Co; 0.37 ± 0.03 and 9.42 ± 0.20 mg kg-1 for Cr; 1.67 ± 0.11 and 26.44 ± 0.28 mg kg-1 for Cu; 0.51 ± 0.04 and 21.18 ± 0.36 mg kg-1 for Mn; 0.56 ± 0.06 and 2.90 ± 0.15 mg kg-1 for Ni; 0.46 ± 0.10 and 37.46 ± 3.00 mg kg-1 for Pb; 0.84 ± 0.06 and 32.81 ± 2.04 mg kg-1 for Sb.

7
  • RAFAEL DOS SANTOS COSTA
  • Phytochemical study and biological activity of Homalolepis bahiensis Turcz. (Simaroubaceae).

  • Leader : EUDES DA SILVA VELOZO
  • MEMBRES DE LA BANQUE :
  • EUDES DA SILVA VELOZO
  • ELISANGELA FABIANA BOFFO
  • VICTOR DIOGENES AMARAL DA SILVA
  • REGINA MARIA GERIS DOS SANTOS
  • JOSEAN FECHINE TAVARES
  • Data: 13 août 2020


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  • This work describes the phytochemical study of Homalolepis bahiensis (Simaroubaceae), an endemic plant at brazilian northeast region. The phytochemical study of the roots and stems was carried out and provided the isolation and identification of 7 quassinoids, 5 canthin-6-one alkaloids, 1 coumarin and 1 phenolic compound. The quassinoids 12-dehydro-klaineanone and 11,12-diacetyl-chaparrinone are described for the first time. Their chemical structures were elucidated by one- and two-dimensional experiments of Nuclear Magnetic Resonance and all molecular formulas was confirmed using mass spectrometry. In vitro citotoxity evaluation of dichloromethane extract of the roots and 5 isolated compounds was carried out against tumoral cell lines and demonstrated promising results. This work also describes the photoluminescent properties of the extracts from the roots, roots barks and stems of H. bahiensis. The observed fluorescent properties guided the cell stainig experiments as well as the isolation and characterization of the cell-labeling properties of 3 canthin-6- one alkaloids at HEP-G2 and HFib under microscopy evaluation. Confocal fluorescence showed remarkable cellular labeling properties of the extracts and isolated compounds.

8
  • ELISSON ANDRADE DE SOUZA
  • TREATMENT OF TANNERY SLUDGE WITH SIMULTANEOUS HYDROGEN GENERATION USING BIFUNCTIONAL PHOTOCATALYTIC SYSTEMS AND OTHER ADVANCED OXIDATION PROCESSES.

  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • LUCIANA ALMEIDA DA SILVA
  • MARCOS DE ALMEIDA BEZERRA
  • SORAIA TEIXEIRA BRANDAO
  • ALEX ANTONIO CONCEIÇÃO SANTIAGO
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • Data: 4 sept. 2020


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  • Producing hydrogen from photocatalytic treatment of leather tannery sludge is a sustainable form of clean energy generation, low cost and waste employability, promoting green chemistry. Besides, the sunlight incidence on the Earth's surface is more than enough for the energy needs of the planet, which is composed of about 43% of visible light. Thus, this work proposes the use of tannery waste obtained from liming bath step, rich in sodium sulfide, to act as a sacrificial reagent and (CdS)x/(ZnO)y composites as a photocatalyst in photocatalytic visible light-assisted hydrogen production employing reduced graphene oxide (RGO) as a cocatalyst. The liming bath sludge, aim of this study, was selected because of its high sulfur content (73.0 g kg-1) and total organic carbon (430.0 g kg-1), which can act as sacrificial reagents in photocatalytic hydrogen production. At 50% (v/v) residue and pH ≥ 13, the photocatalysts RGO/(CdS)1,0/(ZnO)0,4 and RGO/(CdS)1,0/(ZnO)0,73/(ZnS)0,57 showed the best performance for hydrogen production, of 1,6 mmol g-1cat h-1 and 1,4 mmol g-1cat h-1, respectively, mitigating of 80-90% of the sulfide content in the tannery wastewater. Long-term reaction tests indicated that the photocatalysts remain photoactive for a period of 24 hours, and retain photoactivity after three photocatalytic cycles. The materials have demonstrated great potential for application in energy recovery from tanning wastewater with simultaneous sulfide abatement using sunlight. The photocatalyst RGO/(CdS)1,0/(ZnO)0,73/(ZnS)0,57 should be highlighted because it is more eco-friendly due to the lower Cd content and minimal leaching of this toxic metal during photocatalytic treatment. Despite hydrogen production and sulfide abatement, not all pollutants are mitigated in this process. Thus, Advanced Oxidative Processes (AOP) were employed, using 70% H2O2 to degrade the recalcitrant organic matter. Through optimization by the Doehlert matrix, the Sono-Fenton process was identified as the most efficient, promoting a COD reduction around 95% in 30 min.

9
  • PAULA APARECIDA LIMA LOPES
  • Use of solar radiation and sea water in the photocatalytic generation of hydrogen.

  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • LILIAN LEFOL NANI GUARIEIRO
  • LUCIANA ALMEIDA DA SILVA
  • LUIZA AMIM MERCANTE
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 11 sept. 2020


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  • Energy and Environment occupy prominent positions among the biggest challenges of humanity, that try to generate clean energy from abundant and low-cost sources. In this scenario, photocatalytic systems using seawater, sunlight and biomass derivatives to generate hydrogen from water splitting are a promising process based on a renewable energy source that can be added to other strategies to solve global sustainability issues. The present work proposes to develop narrow bandgap photocatalysts based on pure metal calcogenides (CdSe, ZnSe, CdTe) and solid solutions type Cd(1-x)ZnxE (E = Se, SSe, Te, STe and 0 ≥ x ≥ 1) capable of conducting the photolysis reaction of seawater to generate hydrogen with high efficiency, high harvest of visible spectrum and stable to photocorrosion. For this purpose, the coprecipitation method in aqueous solution, argon atmosphere at room temperature was applied in the synthesis of nanoparticles of pure selenides, sulfoselenides, tellurides and sulfotellurides of cadmium and zinc and solid solutions with different ratios Cd:Zn in the start solutions. DRX analyses confirmed the formation of pure materials and solid solutions in cubic phase. The micrographs obtained by TEM revealed the formation of nanospheres of selenides and sulfoselenides with wide size distribution. The materials were also characterized by EDX, DRS, SEM and N2 adsorption. All samples were photoactive for H2 production. Parameters such as pH and concentration of the sacrificial reactant (lactic acid) were studied to improve H2 production. The results confirmed that the use of natural seawater, abundant in electrolytes, is viable for hydrogen production, with an increase of 16% in hydrogen production compared to deionized water when the quaternary sample with excess of zinc (CdZnSSe8) is used. Besides, the insertion of zinc and sulfur in the CdSe and CdTe sphalerite matrix as well as the presence of zinc segregated phases contributed to improve the photocatalytic activity and the stability of the photocatalysts in aqueous medium. Among all photocatalysts tested, the quaternary sample with the highest zinc content on the surface (CdZnSSe8,) was the one with the highest activity in hydrogen production (395.1 μmol g-1 h-1) followed by samples ZnSTe (378.85 μmol g-1 h-1) and CdZnSTe1 (374.7 μmol g-1 h-1).   

10
  • ELIAS REGIS DA SILVA
  • SYNTHESIS, CHARACTERIZATION AND STUDIES OF FUNCTIONAL MOLECULAR MATERIALS BASED ON BENZAZOLES: MESOMORPHISM, PHOTOPHYSICS AND SOLVATOCHROMISM.

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ANDRE ALEXANDRE VIEIRA
  • ELIANE DE OLIVEIRA SILVA
  • SILVIO DO DESTERRO CUNHA
  • IVAN HELMUTH BECHTOLD
  • PATRICIA AKEMI TUZIMOTO
  • Data: 2 oct. 2020


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  • Liquid crystals (LCs) are interesting materials, as they have numerous applications related to the production of consumer goods. Based on this, during the development of this work, three unpublished series of symmetrical molecules with linear structure of the donor-acceptor-donor type (D-A-D), with liquid-crystalline properties, were projecting, synthesized and characterized. The series are based on the 2,1,3-benzothiadiazole (BTD), 2,1,3-benzoselenadiazole (BSeD) and 2-methyl-1,2,3-benzotriazole (BTZ) heterocycles, resulting in a total of 18 molecules. The compounds were characterized using infrared spectroscopic techniques, 1H and 13C NMR, and mass spectrometry. The thermal properties were investigated by DSC, TGA, POM and XRD techniques. The textures observed by POM showed characteristics of calamitic LCs of the nematic (N) and smectic (Sm) type. Derivatives of BTD and BTZ that did not have alkyl chains at the ends were not able to form mesophases. The introduction of additional chains also did not favor obtaining liquid crystals. N and Sm phases were observed for BTD, while BSeD presented exclusively SmC mesophase. The thermal stability for these derivatives was observed between 380-480 ºC in the following order: BTD > BSeD > BTZ. The thermal properties of the BTD, BSeD and BTZ series were compared using compounds of the same size as the alkoxy chain. The replacement of the sulfur atom (S) by selenium (Se) led to the suppression of the nematic phase (N), increased the smectic mesophase C (SmC) range and decreased the decomposition temperature. Se-N type interactions increased side interactions, which justifies the increase in the mesomorphism range. When replacing the S atom in the BTD with N-CH3, the N mesophase was suppressed, the mesomorphism range decreased, as well as the decomposition temperature decreased. The spatial impediment caused by the methyl group is responsible for these effects. In the photophysical properties it was observed that when replacing the S atom by Se the fluorescence emission shifted towards the red in relation to the BTD, while the substitution S by N-CH3 displaced the emission towards the blue compared to the BTD. The BTZ derivative showed the highest quantum fluorescence yield according to the following order: BTZ (0.90) > BTD (0.20) > BSeD (0.16). The results obtained showed that compounds derived from BTD, BSeD and BTZ can be applied in the construction of electronic devices. BTZ derivatives are interesting in the use of efficient luminescent liquid-crystalline materials. BTD derivatives can be used as liquid-crystalline materials with a low melting point. Finally, BSeD derivatives can be applied when the purpose is to use liquid-crystalline materials exclusively from smectic mesophases. Photoinduced charge transfer studies were carried out in solution for BTD, BSeD and BTZ. All of them had their fluorescence suppressed with the addition of C60, which indicates the existence of an intermolecular charge transfer mechanism between species. The Stern-Volmer relationship made it possible to determine the Ksv values in the following order: BTZ (Ksv = 6.31 x 103 molL-1) > BTD (Ksv = 2.18 x 103 molL-1) > BSeD (Ksv = 1, 98 x 103 molL-1). This indicates that the BTZ system is more efficient in the load transfer process.

11
  • LUCILIA ALVES MEIRA
  • Application of X-ray fluorescence spectrometry by energy dispersion associated with magnetic solid phase extraction to determine inorganic species in fuel samples.

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • FABIO DE SOUZA DIAS
  • WALTER NEI LOPES DOS SANTOS
  • VALFREDO AZEVEDO LEMOS
  • MARCOS DE ALMEIDA BEZERRA
  • FÁBIO RODRIGO PIOVEZANI ROCHA
  • Data: 30 oct. 2020


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  • Fuels are widely used in the world, with gasoline and diesel oil being the most employees. However, alternative fuels obtained from renewable resources, such as biodiesel and ethanol, have been extensively explored with the purpose of reducing vehicle emissions and also, due to competitive prices in relation to petroleum products. In this sense, the monitoring of fuel quality and the development of analytical methods, especially for the determination of inorganic contaminants is important because these species can affect the quality of the fuel. The first stage of this work had as objective to explore the association of magnetic solid phase microextraction (MSPME), through the use of CoFe2O4 magnetic nanoparticles (MNP), with energy dispersive X-ray fluorescence spectrometry (EDXRF) for determination of Cd, Pb, Cu, V, Cr and Mn in ethanol. CoFe2O4 nanoparticles impregnated with 1-(2 pyridylazo)-naphthol (PAN) were used as a solid support. After the optimization of the variables (PAN concentration, pH, stirring time, sample volume, ethanol content, contact time and MNP mass), the method was applied to determination of the analytes in fuel ethanol samples with limits of detection (LOD) of 0,012, 0,016, 0,011, 0,013, 0,036 and 0,033 mg L-1 for Cd, Pb, Cu, V, Cr and Mn, respectively. In the second part of this work, the potential of the association of MSPME with the use of the microemulsion break for the extraction of Cd, Cr, Cu and Pb in gasoline samples was explored determination of the analytes by EDXRF. The procedure was based on the formation of a microemulsion of three components: gasoline, n-propyl alcohol and HNO3 0.01 mol L-1. After formation of the microemulsion, TRIS buffer (0.1 mol L-1, pH 8.5) was used to break the microemulsion and adjust the pH, simultaneously. The obtained LODs were 24, 2.8, 16, and 9.7 μg L-1 for Cd, Cr, Cu, and Pb, respectively. The proposed method was applied in the determination of Cd, Cr, Cu and Pb in gasoline samples with precision ranging 2.0 and 8.1%. In the third stage of this work, an analytical method was developed based on the emulsion break associated with the use of MSPME to determine Cd, Cr, V, Pb and Mo biodiesel samples by EDXRF. The emulsion was prepared by mixing the biodiesel sample with n-propyl alcohol and nitric acid at 1% (v v-1) for later contact with the solid phase (CoFe2O4 impregnated with alizarin). Constraint mixing planning was used to optimize the composition of the emulsion and the recommended conditions were: 36% (v v-1) of n-propyl alcohol, 42% (v v-1) of biodiesel and 22% (v v-1) of nitric acid. The proposed method was applied in the determination of Cd, Cr, Pb, V, and Mo biodiesel samples with LOD of 13, 32, 17, 14, and 25, μg kg-1, for Cd, Cr, Pb, V and Mo, respectively. Thus, the use of MSPME using magnetic nanoparticles of CoFe2O4 as a solid support associated with EDXRF proved to be simple and efficient in the determination of toxic metals in fuel samples. In addition, the use of emulsified systems combined with a solid phase reusable was enabled an increase in the extraction capacity of metals and the use of analytical methods with minimal waste generation.

12
  • ADILSON DE SANTANA SANTOS
  • PRODUCTION AND CHARACTERIZATION OF A LABORATORY REFERENCE MATERIAL FROM POWDERED MILK: QUALITY REQUIREMENT FOR INORGANIC ANALYSIS

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • ANA MARIA PINTO DOS SANTOS
  • MARCOS DE ALMEIDA BEZERRA
  • ANTONIO FERNANDO DE SOUZA QUEIROZ
  • IEDA SPACINO SCARMINIO
  • Data: 4 déc. 2020


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  • Powdered milk and its derivatives are widely consumed worldwide, which requires the development of Reference Materials to assess the accuracy of the analytical methodologies that are used to analyze these food matrices. In this context, this study proposes the development of two studies: the first consists of the preparation and characterization of a Laboratory Reference Material (LRM) from powdered milk for inorganic analysis and the second aims at the simultaneous determination of chromium and iron in samples of this food using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). For the development of the LRM, the recommendations of ISO Guides 30-35 were met through the steps of homogeneity, stability, characterization, and uncertainty assessment. Through parameters obtained through the one-way analysis of variance (ANOVA) it was possible to affirm that the material is homogeneous and stable concerning Ca, Fe, K, Mg, Na, P, and Zn. As an alternative to ANOVA, multivariate analysis (PCA and HCA) was also applied to the data set and made it possible to extract a greater amount of information, such as that for Ca, K, Na, and P, in PC1, and Fe and Mg, in PC2, are the most responsible for the dispersion of results when a minimum mass of 100 mg was studied. The characterization study was established through an interlaboratory comparison with the participation of 15 laboratories, one international. The property values, as well as the combined uncertainty (URM) were as follows (mg g-1): Ca (8.795 ± 1.137), Fe (0.107 ± 0.017), K (11.727 ± 1.983), Mg (0.841 ± 0.125), Na (3.654 ± 0.672), P (7.572 ± 1.174), and Zn (0.032 ± 0.005). Therefore, the new material can be a good alternative to evaluate routine procedures, quality control, and validation of analytical methods related to samples of milk and dairy products. In the simultaneous determination, the primary resonance line chosen for Cr was 357.869 nm (the highest sensitivity for this element) and the secondary line (358.120 nm) for Fe, which are in the same spectral window of the detector. After the optimized conditions, five milk samples were analyzed and the chromium concentration found varied from 408 to 805 ng g-1. Among the five samples, three had an iron concentration lower than 19 µg g-1 and in the other two, the concentration varied from 151 to 191 µg g-1. Thus, the proposed method has precision, accuracy, and sensitivity for the determination of chromium and iron in milk samples.

13
  • JOÃO HONORATO SANTOS NETO

  • LOW COST INSTRUMENTATION FOR CHEMICAL ANALYSIS BASED ON DIGITAL IMAGES

  • Leader : ANA MARIA PINTO DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ANA MARIA PINTO DOS SANTOS
  • SERGIO LUIS COSTA FERREIRA
  • VALFREDO AZEVEDO LEMOS
  • LIZ OLIVEIRA DOS SANTOS
  • CLEBER GALVAO NOVAES
  • FABIO ALAN CARQUEIJA AMORIM
  • Data: 15 déc. 2020


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  • The works carried out in this Thesis used the innovation of the methods of chemical analysis by digital image with instruments built from accessible and low cost materials when compared to other instruments. Two devices were built to capture digital images of colorimetric reactions. In the first work (Chapter I), a webcam was used as a detector and a wooden box for external light isolation, to capture images of colorimetric reactions, using the chromogenic reagent 1,2 orthophenanthroline, in order to quantify Fe (II )  and Fe (III) in white wine samples. The method presented accuracy of 3.47% for Fe (II) and 5.36% for total Iron with Limit of Detection (LD) of 0.042 mg/L and Limit of Quantification (LQ) of 0.141 mg/L. Six wine white samples was analyzed and the concentrations found varied between 0.41 to 1.67 mg/L for Fe (II) and between 0.69 to 1.71 mg/L for total iron. In the second work (Chapter II), a digital camera microscope-type was used as a detector coupled to a system with mechanical aspiration built from polyvinyl chloride (PVC) tubes with the aim of to capture images and measure the colorimetric variation of a reaction using diacetylmonoxime (butane-2,3-dione monoxime) for determine urea in UHT liquid milk. This method was subjected to three different mathematical treatments that showed accuracy between1.58 to 5.77% with LD ranging from 0.35 to 1.77 mg/L and LQ ranging from 0.52 to 2.54 mg/L. Eight samples milk were analyzed and the urea content varied between 161.37 to 420.33 mg/L. Multivariate optimization and analytical validation processes were applied in the two methods developed. Despite the studies using instruments with simple and low-cost materials, the figures of merits as linearity and accuracy were satisfactory for the purposes of the analyzes. The concentrations found in the samples are similar to studies applied for same sample. It was concluded that simple and low cost instrumentation for digital image analysis can be an alternative for several areas where complex and costly instrumentation is the only alternative. In addition, the versatility in the construction of equipment of this nature allows the analyst to adapt them according to his needs and this characteristic is very important in view of the diversity of location daily in the scientific environment.

14
  • IURA MUNIZ ALVES
  • Phytochemical study of Balfourodendron molle (Miq) Pirani.

  • Leader : EUDES OLIVEIRA CUNHA
  • MEMBRES DE LA BANQUE :
  • EUDES DA SILVA VELOZO
  • JOSEAN FECHINE TAVARES
  • LUCAS SILVA ABREU
  • PAULO CEZAR VIEIRA
  • PAULO TEIXEIRA DE SOUSA JÚNIOR
  • Data: 16 déc. 2020


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  • The Rutaceae family has approximately 160 genera and 1900 species distributed in tropical and temperate regions, with great occurrence in Central and South America, southern Africa and Australia. Species of the family are perennial, mostly shrubs and trees. The family has already placed into some orders including Rutales, Geraniales, Sapindales and has genera of great economic importance, fruit species and others used in traditional medicine. Genera and species of the family are known for the biosynthesis of alkaloids, coumarins, lignans, flavonoids and limonoids. Alkaloids derived from anthranilic acid are considered chemotaxonomic markers of the Rutaceae family. Among the genera, Balfourodendron is composed of two species - B.riedelianum and B. molle - both distributed in several Brazilian states, mainly Minas Gerais, Bahia, Mato Grosso do Sul and Ceará. This research presents the phytochemical study of a specimen of the species B. molle collected in the Chapada Diamantina region – Bahia -, which resulted in the isolation and identification of quinolonic alkaloids, furoquinoline alkaloids, coumarins, furofuranic lignans, flavonoids and limonoids isolated from the root, stem, leaves and inflorescences. In the separation procedures, classical chromatography and HPLC were used, on analytical and preparative scales. For clarification of structure, RMN 1H e 13C experiments, uni and bidimensional. In addition, a study on a crude extract of the inflorescences was carried out in order to evaluate the composition of the polyphenolic compounds. Using HPLC-ESI-MSn and from the fragmentation patterns observed in the experiments results it was possible to propose the putative identification of C and O-glycosylated flavonoids.

15
  • MESSIAS SANTOS PASSOS
  • Bioremediation, Chemical and Biotechnological Profiling of Cadmium Resistant Filamentous Fungi
  • Leader : REGINA MARIA GERIS DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • DÉBORA DE ANDRADE SANTANA
  • ELISANGELA FABIANA BOFFO
  • FERNANDO FAUSTINO DE OLIVEIRA
  • MADSON DE GODOI PEREIRA
  • PAULO ROBERTO RIBEIRO DE JESUS
  • REGINA MARIA GERIS DOS SANTOS
  • Data: 17 déc. 2020


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  •  

    Filamentous fungi are widely disseminated in various habitats as decomposers of organic matter, among which are disease-causing species in plants and animals, including humans. On the other hand, microorganisms belonging to the Fungi Kingdom also present a set of qualities that are of extreme interest to the food and pharmaceutical industries and, more recently for employment in environmental recovery processes. In this work, the isolation of soil fungi was performed to investigate its biotechnological potential, its ability to resist toxic metal stress and its possible application in bioremediation processes, as well as the evaluation of the effect of this stress on the production of substances of special metabolism. In the isolation of the species, the technique of serial dilution of soil suspension was used, and the isolates were identified at the gender level by optical microscopy. The isolates were submitted to tests of investigation of the production of enzymes and fungicide and antibacterial agents, by development in Petri dish. They were also submitted to tolerance, resistance and bioaccumulation tests of cd (II) metal cations with analysis by flame atomic absorption spectroscopy (FAAS).Crude extracts from mycelium with organic solvent in an ultrasonic bath and from fermented broth were obtained by liquid/liquid partition with organic solvent from the species that showed greater resistance to metallic stress, both of the fungi developed in cation containing the cations and in a free medium.The extracts were studied in a mass spectrometer by electrospray ionization with an ion trap analyzer (EM-ESI-Ion Trap) for the presence or suppression of sorbcillinoid derivatives. From a total of 51 isolates, species belonging to 4 different genera were detected. In the antagonism tests, approximately half of the isolates presented a degree of growth inhibition of the microorganisms tested, with emphasis on antifungal activity.More than 70% of the isolates presented high proteolytic, amylolytic and lipolytic activity. Many isolates showed tolerance to Cd (II) at concentration 100 mg.L-1, but only four isolates, of the genus Penicillium, showed high resistance to metallic stress developing in concentrations between 500 mg.L-1 and 9,000 mg.L-1.The Penicillium sp. M04 presented the highest bioaccumulation potential (in vivo) with the ability to remove 79.48 mg/g of Cd (II) from the growth medium. In the biosorption test, the isolate Penicillium sp. M04 also presented the highest Cd (II) mass values adsorbed by gram of biomass of its mycelium (inactive). The four species had their chemical profiles affected by metallic stress. The extract fractionation of the fermented broth of Penicillium sp. M01 led to the isolation of the polyketide sorbicillinoid trichodimerol. The study showed the great potential of fungi to perform bioremediation processes, because they were highly resistant and performed bioaccumulation and biosorption of Cd (II).

2019
Thèses
1
  • GLAUBER ANTONIO ALBUQUERQUE DOURADO
  • REACTIVITY OF 2-AMINO-1,4-NAFTOQUINONE IN HANTZSCH REACTIONS: TRICOMPONENT SYNTHESIS OF FUNCTIONALIZED AZAPOLICYCLES

     
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • LOURENCO LUIS BOTELHO DE SANTANA
  • SILVIO DO DESTERRO CUNHA
  • Data: 1 févr. 2019


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  • The aim of this work was to develop nitrogenous heterocyclic synthesis methodologies, based on the Hantzsch methodology, from multicomponent reactions that were adapted to the principles of green chemistry. The main building block studied was 2-amino-1,4-naphthoquinone, a molecule that has the characteristic of the junction of a quinone nucleus and the enaminone portion. The synthesis of pyrimido- [4,5-b] -quinoline-tetraones derivatives, took special note because these types of molecules have proven biological properties. A novel synthetic route was developed in a trichomponent form using a mixture of 2-amino-1,4-naphthoquinone, benzaldehyde derivatives and barbituric acids, various conditions were tested, and the best result was obtained using reflux in acetonitrile and aminosulfonic acid as catalyst for the synthesis. This new methodology creates another option for the synthesis of this product. By replacing the reaction solvent with ethanol and removing the catalyst to adapt the process to the principles of green chemistry, a new reaction pattern was observed producing unpublished molecules, dihydrobenzo [g] pyrimido [4,5-b] quinoline-tetraone were obtained with the formation of an exocyclic double bond, other than the pyrimido- [4,5-b] -quinolines-tetraones, where this double bond is endocyclic, the synthesis of arylidene in Meldrum's acid was studied, degradation of this acid after 24h at reflux with ethanol. The reaction for the production of the 13phenyl-6,13-dihydro-6-azapentacene-5,7,12,14-tetraone analogs was proposed by our GPSQ research group and then we developed a new proposal that replaces Meldrum acid with malonic acid, reaction with similar yields.
     
     
2
  • ANA CLARA RODRIGUES DE MAGALHÃES
  • GAS REAGENTS PRODUCTION BY PERSULFATE THERMAL DECOMPOSITION  AND ITS EFFECTS ON EDIBLE VEGETABLE OILS SAMPLE PREPARATION.

  • Leader : RODOLFO DE MELO MAGALHAES SANTANA
  • MEMBRES DE LA BANQUE :
  • RODOLFO DE MELO MAGALHAES SANTANA
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MADSON DE GODOI PEREIRA
  • Data: 5 avr. 2019


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  • Sample preparation step usually implies in high costs and time consumption, in despite of its important play holed in analytical results quality. In this sense, development of new sample preparation strategies that increase analytical throughput and provide more sensitive and accurate analytical methods has being a subject of interest. Thus, the present work aiming to develop a new sample preparation based on the production of insitu reagents from ammonium persulfate decomposition irradiated by microwave in a closed system for the analysis of samples with high-unsaturated fat content. The decomposition parameters, concentration of HNO3 (3.5 to 14.0 mol L-1), decomposition temperature (150 to 210 °C) and decomposition time (23 to 40 min) were evaluated to ensure decomposition efficiency as well as higher in-situ reagent production rate. Therefore, 8 mL of HNO3 were added to safflower oil samples (m ≈ 0.250 g) in presence or absence of auxiliary decomposition vial containing (NH4)2S2O8 solution (2.0 mol L-1). Persulfate effects on digestion step were evaluated by comparison with procedures performed using only HNO3 taking the dissolved carbon content (DOC) as analytical response. The proposed method was applied to samples of edible oils from safflower, coconut, flaxseed and chia to elemental analysis. Decomposition optimum conditions with persulfate indirect application were set at 210 °C with irradiation time of 40 min and HNO3 concentration equal to 7.0 mol L-1. Reagents in-situ generation by persulfate thermal decomposition led to a greater sample solubilization and clearer digested in face of those obtained only using HNO3. However, the chemical evidences obtained from final digested in both procedures indicated that byproduct gas produced by persulfate thermal decomposition did not act as auxiliary oxidizing reagents. Under optimum conditions, DOC levels were equal to 0.61 ± 0.02 and 2.2 ± 0.4 g L-1 in nitric/persulfate and nitric digested, respectively. In addition, a significant difference was observed in relation to the digested obtained when persulfate was applied directly to the sample (2.9 ± 0.3 g L-1). The proposed method presented good accuracy with results in agreement with FDA U.S. Food and Drug Administration reference Method (p = 0.05). In addition, good precision (RSD <10%, N= 7) was found, with wide linear ranges and good linearity (R2≥ 0.999) and LOD ranging from 0.0005 to 0.096 mg L-1. The proposed method allowed the determination of As, Ca, Cd, Cr, Fe, Mn, Na, Ni, P, Pb, Se and Zn in edible vegetable oil samples by ICP OES and ICP-MS. However, it was verified systematic errors occurrence to Cu, for all evaluated oils, and Fe in safflower oil. Thus, (NH4)2S2O8 indirectly use has proved to be an alternative method to nutrients and contaminants determination in edible vegetable oil samples with good analytical productivity, accuracy and precision.

3
  • JOÃO CARLOS SILVA CONCEIÇÃO
  • In vitro and in silico studies of biotransformations of phenolic substances

  • Leader : ELIANE DE OLIVEIRA SILVA
  • MEMBRES DE LA BANQUE :
  • ELIANE DE OLIVEIRA SILVA
  • JORGE MAURICIO DAVID
  • SAMUEL SILVA DA ROCHA PITA
  • Data: 3 mai 2019


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  • Biotransformation processes have an important role in chemical derivatization since the enzymes and their cofactors are generated in situ, acting as efficient catalysts that modify different substrates. In general, biotransformation reactions present high selectivity and are according to the Green Chemistry principles. Phenolic substances have numerous bioactivities and are useful for several industries to producing derivatives with high added value. Within this context, in the present study, the biotransformations of three phenolic substances were analyzed using two strains of filamentous fungi: Trametes versicolor ATCC 200801 and Aspergillus brasiliensis ATCC 16404. The fungus T. versicolor is a traditional source for the enzyme laccase (an oxidoreductase). The chemical profiles of the biotransformations were evaluated by using Thin Layer Chromatography (TLC), High-Efficiency Liquid Chromatography coupled to Diode Array Detector (HPLC-DAD) and Gas Chromatography coupled to Mass Spectrometry (GC-MS), and the most promising processes for the biotransformation of the evaluated substrates were selected. The obtained derivatives were isolated by chromatographic column using silica gel as the stationary phase and ethyl acetate, hexane and methanol as the mobile phase. Spectroscopic and spectrometric techniques were used to determine the chemical structures of the derivatives. It was possible to observe that T. versicolor biotransformed only methyl p-coumarate, resulting in the formation of three derivatives: cumaric acid, yield of 12.18 %; methyl caffeate, yield of 3.56%; and (E)-methyl-3- (4-methoxyphenyl) acrylate (identified in mixture). Biotransformations by A. brasiliensis resulted in the conversion of methyl p-coumarate into three derivatives (detected by GC-MS): acetophenone, 1-(4-hydroxyphenyl) propane-1,3-diol and 4-(3-hydroxypropyl) benzene-1,2-diol; methyl ferulate was biotransformed into (4)-methyl-3-(4-hydroxy-3-methoxyphenyl)-3-methoxyacrylate (10.31 % yield). Additionally, the biotransformation of the three phenolic substrates by T. versicolor was studied by in silico assays. It was considered that the enzyme present in the reaction medium was laccase and the molecular docking was carried out. The AutoDock v.4.2 and Pymol softwares provided a prediction of the orientation and preferential conformation that the phenolic substrates took on the active site of laccase. The results indicated that the three substrates interacted spontaneously with the biological receptor, but with different free energy values (ΔG): ΔG p-methyl coumarate = -6.89 Kcal.mol-1, ΔG methyl ferulate = -7, 37 Kcal.mol-1 and ΔG methyl caffeate = -7.55 Kcal.mol-1. The ligand-protein complex consisting of methyl p-coumarate-laccase was the least stable one, explaining the occurrence of biotransformation of this substrate by T. versicolor. Thus, it was possible to demonstrate that methyl p-coumarate interacted more efficiently with the laccase site, allowing the occurrence of hydrolysis, hydroxylation and methoxylation reactions.

4
  • HEMERSON DANTAS DOS SANTOS
  • Chemometric analysis of NMR data of coffee from the Chapada Diamantina region (state of Bahia, Brazil)

  • Leader : ELISANGELA FABIANA BOFFO
  • MEMBRES DE LA BANQUE :
  • ELISANGELA FABIANA BOFFO
  • PAULO ROBERTO RIBEIRO DE JESUS
  • GISELE ANDRE BAPTISTA CANUTO
  • ROSILENE APARECIDA DE OLIVEIRA
  • LOURDES CARDOSO DE SOUZA NETA
  • Data: 3 mai 2019


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  • The coffee from the Chapada Diamantina region, in the state of Bahia, Brazil, are considered high quality, due to the use of adequate production and processing criteria throughout the entire process, has provided this food with a high degree of quality and excellence, which is directly linked to its final chemical complexity. Studies about the chemical profile of coffee have correlated chemical composition, quality standards and data about geographical origin, thus contributing to antifraud methodologies. This research used Nuclear Magnetic Resonance (NMR) to study the chemical composition of coffee from Chapada Diamantina, in order to contrast them to coffee from other regions. We analyzed 37 commercial samples, which are classified, accordingly to their quality, as traditional, superior and gourmet. 1H NMR spectra were acquired on the Varian Inova 500 spectrometer of the Laboratório Baiano de Ressonância Magnética Nuclear (LABAREMN/UFBA). Analyzing the NMR data, we identified characteristic signals of chlorogenic acids (CGA), such as caffeoylquinic acids [6.74 - 6.80 m], alkaloids and xanthines as trigonelline [4.43 s] and caffeine [3.24 s, 3.41 and 3.84 s]. We also observed characteristic signals of furans (5-HMF [9.44 s]), amides and amino acids such as acrylamide [5.83 and 5.99 m] and L-alanine [1.39 d (6 Hz)]. Finally, we identified signals of organic acids, such as lactic acid [1.35 d (7 Hz)] and acetic acid [1.96 s], as well as carbohydrates and lactones, such as myo-inositol [3.27 - 3.35 m] and γ-butyrolactone [2.15 - 2.18 (m)]. The pretreatment of the 1H NMR spectra was made using alignment, autoscaling, and normalization (norm one). Then, the principal components analysis was performed. In the PCA scores plot, we observed four groups, which were denominated Chapada Diamantina, Bahia, Brazil and gourmet/superior. The coffee from Chapada Diamantina presented a characteristic chemical profile, which distinguished them from the others, mainly because they contain higher levels of lipids. The coffee from that region which present highest commercial value and which are classified as gourmet were grouped with Colombian coffee and some national ones with similar quality standards. This group presented higher levels of chlorogenic acids and trigonelline, substances which contribute to the pleasant aroma and taste of the beverage. The chlorogenic acid signals of coffee from other regions of the state of Bahia showed very low intensities. Coffee from other Brazilian states presented higher quinine levels in comparison than those from Bahia, and lower levels of chlorogenic acids than those from Chapada Diamantina. The results show that 1H NMR, coupled with chemometrics, is a very effective tool to discriminate coffee, allowing us to obtain from the data set as much information as possible, and to highlight its most important pieces. This methodology, whose efficiency has been proved by various studies, can help us understand complex mixtures.

5
  • KLEBER OLIVEIRA VISCARD JUNIOR
  • STUDY OF THE JOANES RIVER BASIN WATER QUALITY EVOLUTION
  • Leader : VANIA PALMEIRA CAMPOS
  • MEMBRES DE LA BANQUE :
  • VANIA PALMEIRA CAMPOS
  • LEONARDO SENA GOMES TEIXEIRA
  • LUCIANO MATOS QUEIROZ
  • Data: 3 juin 2019


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  • The Joanes River Basin is an important spring located in the Metropolitan Region of Salvador and responsible for about 40% of the water supply of the city of Salvador and the region. Despite this, the environmental aggressions that the river Joanes and its tributaries have been suffering, such as the dumping of domestic and industrial sewage, destruction of riparian forests, undue land occupation, among others, are daily actions suffered by them and can greatly impact the quality of its waters. This work sought to study the evolution of the water quality of this basin over the years 2008 to 2017, through the analysis of physicochemical parameters such as pH, dissolved oxygen, turbidity, among others, and analysis of metals such as cadmium, lead, copper, chromium, nickel and zinc, determined by ICP OES. The data obtained were used to calculate indexes such as WQI (Water Quality Index), TSI (Trophic State Index) and WLI (Aquatic Life Preservation Index), which are used to classify waters according to their quality. According to the calculated indexes, there are variations in the classification of waters that indicate "optimal" quality to "very bad" along the course of the river and its tributaries. It also showed that there was no significant variation in water quality over the years, however, it presents a negative evolution by considering the course of the river from the source to the mouth. By making a comparative approach between the IQA and IVA indexes, the inefficiency of using the IQA as a tool for assessing the quality of the Basin is evidenced, considering that, in more than 70% of the points sampled, the classifications were inconsistent with the presented in the IVA, which uses indisputable parameters of significance, such as the concentration of toxic chemical contaminants. In addition, in more than 80% of the points sampled, there was a violation of the parameters regulated for class 2 fresh waters, in accordance with CONAMA Resolution 357/05. In this way, it is expected that this work serves as a document to encourage concrete actions by the government, aiming, in an emergency time, to reverse the harmful anthropic emissions that have been degrading for a long time the quality of the waters of the Joanes River Basin.

6
  • Leonardo de Oliveira Aguiar
  • 5,8-π-EXTENDED QUINOXALINE DERIVATIVES AS GOOD CHROMOFORMS FOR PHOTOLUMINESCENCE APPLICATIONS

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ALOIR ANTONIO MERLO
  • ANDRE ALEXANDRE VIEIRA
  • MAURICIO MORAES VICTOR
  • SILVIO DO DESTERRO CUNHA
  • Data: 14 juin 2019


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  • In this work, the synthesis, characterization and the study of thermal and photophysical properties of liquid-crystalline materials containing quinoxaline heterocycle are described, whose derivatives are known to present good performance in the construction of polymers, OLEDs and exhibit pronounced biological activity. To obtain new liquid crystals it is proposed the functionalization this heterocycle at positions 5 and 8, varying the coupled peripheral groups as a function of the alkyl chain length. The structural characteristics of the proposed molecules are capable of presenting calamitic mesomorphism and luminescent properties. The synthetic route to prepare the final compounds begins with the 4,7-dibromo-2,1,3-benzothiadiazole compound, involves reductive sulfur extrusion reaction, followed by cyclization using glyoxal. The final step of Sonogashira cross-coupling reaction allows obtaining the desired π-extended compounds. The synthesized molecules were characterized by spectroscopic techniques. The thermal properties were evaluated by DSC, TGA and MOLP, in addition to studies such as DRX. The final compounds exhibited nematic and smectic liquid-crystalline phases, typical for calamitic structures. The photophysical properties were studied by absorption and emission spectra in solution in chloroform, and it was possible to observe intense green luminescence when irradiated with UV-Vis light. The efficiency of the photoluminescence was evaluated by relative quantum yield in solution and the electrons lifetime study allows characterizing this process as fluorescence. In addition, solvatochromism was studied, applying the Lippert-Mataga equation, in order to evaluate the influence of the polarity of the solvent on the optical properties. Studies to determine the ability to act as a fluorescent sensor were performed through the interaction of quinoxaline derivatives with different metals. The photophysical properties of these materials were also investigated in solid phase by absorption and emission spectra and absolute quantum yield. The evaluation of the influence of heating in the optical properties was verified as well as the morphology of the thin films. Theoretical calculations, through DFT, allowed the comparison of the experimental data with the theoretical values.

7
  • BRUNA OLIVEIRA DO NASCIMENTO
  • PHYTOCHEMICAL STUDY AND  BIOLOGICAL ACTIVITIES EVALUATION OF THE EXTRACTS AND CONSTITUENTS OF Macrolobium rigidum (R.S Cowan)

  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • JORGE MAURICIO DAVID
  • SILVIO DO DESTERRO CUNHA
  • ELIANE DE OLIVEIRA SILVA
  • LOURINALDA LUIZA DANTAS DA SILVA SELVA DE OLIVEIRA
  • CLAYTON QUEIROZ ALVES
  • Data: 18 juin 2019


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  • This work describes the first phytochemical and biological study of aerial parts of Macrolobium rigidum. The extracts obtained by partition of the crude methanolic extract of the leaves and the stem of M. rigidumwere submitted to in vitrobiological activity tests: cytotoxic against A. salina microcrustacean, evaluation of the antioxidant activity measured by the DPPH radical scavenging assay method , anticholinesterase, by the microplate method, evaluating the inhibition of the acetylcholinesterase enzyme, and antimicrobial against the bacteria S. aureusP. aeruginosa,Salmonellaand E. coli, by means of determination of the minimum inhibitory concentration (MIC) detected with the aid of the developer resazurin. The determination of the total phenolic content by the Folin-Ciocalteu method was also performed. None of the extracts presented toxicity, in contrast to the DPPH radical, the extracts in EtOAc presented activities in concentration of 10μg.mL-1, the extracts in EtOAc and in BuOH of the stem presented minimum inhibitory concentration against Salmonellaof ≤125μg.mL-1, in comparison to P. aeruginosa, leaf extracts had lower MIC values. The contents of total phenolic compounds in extracts of M. rigidumranged from 46.438 ± 0.006 to 446.668 ± 0.018 mg EGA/ g of extract. The triterpenes friedelin and taraxerol, the steroid mixture composed of β-sitosterol, capesterol and stigmasterol, the flavonoids, among them apiginine and an unusual glycosylated coumarin, were all isolated by means of chromatographic methods, all identified by analysis of the data of 1H, 13C, HSQC and HMBC NMR spectra, IR region and UV-vis region spectra and mass spectrum.

     

8
  • LEILA SANTANA VIANA BARBOSA
  • Evaliation of amino acids and glutathione coated CdTe quantum dots interaction to urine and dietary supplements analysis

  • Leader : RODOLFO DE MELO MAGALHAES SANTANA
  • MEMBRES DE LA BANQUE :
  • RODOLFO DE MELO MAGALHAES SANTANA
  • MARIA DAS GRACAS ANDRADE KORN
  • JOSUE CARINHANHA CALDAS SANTOS
  • Data: 28 juin 2019


  • Afficher le Résumé
  • Amino acids (AA) are the main constituents of proteins, and their deficiency or accumulation leads to health damage. Different methods were developed using quantum dots (QD), as photoluminescent probes for indirect AA determination in different matrices.These methods were based on the turn-off-turn-on strategy, which consists in quencher removal (usually metal species) from QD surface by interaction with analytes.Thereby, the present work aims to evaluate AA-QD for the direct analytical methods and its application in urine and supplements samples. Sensitization assays of glutathione-coated CdTe QD (GSH-CdTe) with different sizes were performed against 7 amino acids alone and they were divided according to the properties of their side chain. Experiments with different temperatures and ionic strength were performed to evaluate the quenching mechanism and AA-QD interaction type. Chemical parameters of the probe, such as pH (5 to 10), buffer concentration (0.1 to 0.8 mol L-1), QD size (2.2 to 3.0 nm) and concentration (2.5 to 35 μmol L-1) were evaluated to ensure greater method sensitivity. It was observed that AA with positive charge or neutral polar chains, namely L-histidine (His) and L-threonine (Thr), have reduced 90% of nanocrystal fluorescence. Reaction parameters assesment has shonw that in ammoniacal buffer (0.25 mol L-1) at pH 8.0 GSH-CdTe (2.2 nm) responded only to His, indicating specificity of luminescent probe to the analyte. Studies on the His-QD mechanism suppression and interaction indicated the occurrence of static quenching with complex association constant (ka) ranging from 2.81x10-5 to 9.7x10-6 L mol-1 from 20 °C to 35 °C. In addition, no variation of ka (Δka <11%) was observed changing ionic strength suggesting preferently His-QD interations of Van der Waals force and/or hydrogen bonding.The thermodynamic parameters of His-QD interaction were determined using the Van 'Hoff equations, obtaining values of ΔH = -160.5 kJ mol-1 K, ΔS = -0.858 J mol-1 and ΔG of -411.931 to -424.803 kJ mol-1 K (T = 20 to 35 °C). Parallelism was observed between the calibration curves in aqueous solvent and sample indicating the absence of matrix effect. Under optimal conditions the developed method presented a linear range of 2.5 to 35 mmol L-1 (R = 0.9970, n = 7). The detection limit was 1.1x10-3 mol L-1 (0.170 mg mL -1), showing good precision with RSD <2.5% (for 2.5 and 20 mmol L-1; n = 6). The accuracy method was evaluated by addition and recovery assays for two to three concentration levels in real triplicate in urine and supplement samples, presenting adequate recovery values for both samples demonstrating good accuracy.The method was applied to urine and dietary supplement samples. Histidine was not detected in urine samples. However, in supplement samples, His was determined in amounts equal to 135±5 and 417.2±0.2 mg per tablet.

9
  • ANA CAROLINE NEVES DA SILVA
  • Study and application of catalysts based on lanthanum, strontium and cobalt in the catalytic combustion reaction of methane. 

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • SORAIA TEIXEIRA BRANDAO
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • ROGER THOMAS FRANCOIS FRETY
  • Data: 28 juin 2019


  • Afficher le Résumé
  • In the present work were studied perovskite catalysts La1-xSrxCoO3 (x = 0.0; 0.2; 0.4) and cobalt oxide, synthesized by the citrate method. The synthesis methodology favored the formation of nanostructured solids with crystalline phases. The obtained samples were characterized and evaluated in the methane catalytic combustion reaction aiming to analyze, mainly, the catalytic effect caused by the partial replacement of lanthanum by strontium in the perovskite site A. The catalytic properties of the catalytic systems were investigated and related to the structure. The materials were analyzed by X-ray diffraction (XRD), thermogravimetric analysis (ATG), surface area measurement by the BET method, transmission electron microscopy (TEM), diffuse reflectance visible Uv spectroscopy (Uv-vis DRS). , hydrogen reduction at programmed temperature (TPR-H2) and X-ray fluorescence (FRX). As a catalytic test, all samples were submitted to the combustion thermoprogrammed surface reaction (TPSR).The results indicate that all studied systems are active the catalytic combustion reaction of methane and the insertion of strontium in the perovskite structure favored the reduction of catalyst activation energy and ignition temperature. A relationship between reductibility of cobalt species and catalytic activity in the materials was also observed. The system that showed lower activation energy, lower ignition temperature and higher reducibility was the La0,8Sr0,2CoO3. system.

10
  • Maiara Oliveira Passos
  •  

    Effect of Isotopic Substitution on Hydrogen Abstraction Reaction Speed Constants H3COCOH + O (3P)

     

     

  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • TIAGO VINICIUS ALVES
  • MARCOS MALTA DOS SANTOS
  • ORLANDO ROBERTO NETO
  • Data: 4 juil. 2019


  • Afficher le Résumé
  • In this study, the energetic, structural, and spectroscopic parameters of the stationary points generated by the abstraction reaction O (3P) + X3COCOX → X3COCO + OX (R1 and R3) and X2COCOX + OX (R2 and R4), in which X = H or D, were obtained at DFT/BB1K/maug-cc-pVTZ, level of theory. At this level, the height of the classical barriers, V ‡, for (R1) and (R2), were 10,45 and 12,05 kcal/mol, respectively. In the aspect of chemical kinetics and dynamics, the thermal rate constants were determined using the CVT/SCT approach, in a wide temperature range (T= 250 - 2000 K). At lower temperatures, the quantum tunneling plays an important role in the k(T). At 250 K, for example, the CVT/SCT thermal rate constant (3,27x10-15 cm3molécule-1s-1) is 4.144 times greater than the CVT counterpart (7,89x10-19 cm3molécula-1s-1). For the reactions with deuterium, the total constant CVT/SCT (5,22x10-16 cm3molécula-1s-1) is 1.717 times greater than the CVT counterpart (3,04x10-19 cm3molécula-1s-1). The kinetic isotopic effect at this temperature, were KIER1/R3 TST = 12,38 e KIER1/R3 CVT/SCT = 6,26; KIER2/R4 TST = 15,23 e KIER2/R4 CVT/SCT = 4,94.

11
  • THIAGO ANASTACIO DA SILVA
  • Oxi-CO2 parameter evaluation using LaNiO3 perovskites

     
  • Leader : LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MEMBRES DE LA BANQUE :
  • CAMILA RIBEIRO DE OLIVEIRA FÉLIX
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • SORAIA TEIXEIRA BRANDAO
  • Data: 5 juil. 2019


  • Afficher le Résumé
  • Carbon dioxide reforming of methane to syngas production was studied employing LaNiO3-based perovskite catalysts (LaNiO3, LaNi0,7Fe0,3O3 e La0,7Ce0,3NiO3), synthesized by the citrate route, objectifying contrast the catalytic performances based on substitutions in the perovskite structure, evaluating them in the catalytic reaction of the dry reform of methane in the presence of oxygen. The catalysts were characterized by TGA/DTG, XRD, TPR-H2, TPSR, TPO, specific surface área by the BET method, besides being tested in the reaction for 20h. It being verified that the substitution with Ce in the structure of LaNiO3 provides conversions and selectivities similar to perovskite in its reference state, but La0.7Ce0.3NiO3 is more viable than the others because presented the highest resistance to coke deactivation in the studied process, this being an effect comes from the addition of cerium which provides a greater stability to the structure. Afterwards, an analysis was performed to find the ideal temperature to conduct the reaction, verifying the effect of temperature on the activity, selectivity and resistance to deactivation by deposition of coke. The tests were performed at three different temperatures of 600 to 800°C, with increments of 100°C, and the results indicated that the catalytic system was sensitive to temperature variation, presenting the best results at 800°C, in which the occurrence of some parallel negative reactions to the process becomes disadvantaged. Finally, an analysis was made of the advantages of using Oxi-CO2 in favor of simpler reforms, such as DRM, concluding that Oxi-CO2 produces the best activity responses, selectivity and resistance to coke deposition , due to the addition of oxygen in the reaction

12
  • IGOR ARAÚJO LINS
  • Theoretical Study of Hydrogen Abstraction Reactions of Methyl Formate by OH Radical 

  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • TIAGO VINICIUS ALVES
  • ROBERTO RIVELINO DE MELO MORENO
  • ORLANDO ROBERTO NETO
  • Data: 5 juil. 2019


  • Afficher le Résumé
  • In this study, the structural, energetic, and spectroscopic parameters for the stationary points generated by the hydrogen abstraction reaction between methyl formate and the OH radical were obtained at the level of theory M06-2X/maug-cc-pVTZ. This approach was chosen after an energetic benchmark construction using the CCSD(T)-F12a/CBS classical barrier height and reaction energy as a reference. The values of classical barrier height (V ‡) for (R1) and (R2) were 1.27, and 2.40 kcal.mol−1, respectively. With the inclusion of the zero-point energy, these energetic parameters were 0.2, and 1.2 kcal.mol−1, respectively. The enthalpy of reaction at 0 K at this level were -19.1, and -18.5 kcal.mol−1. In the chemical kinetics and dynamics study, we applied the classical transition state theory (TST), and canonical variational theory (CVT) with small-curvature tunneling (SCT) in a wide temperature range (233 - 2500 K). The thermal rate constant obtained are in good agreement with the theoretical and experimental predictions.

13
  • JAMILLE SILVEIRA MATOS
  • SYNTHESIS AND REACTIVITY OF 3-ACETYL-THIOENAMINONES

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • ELIANE DE OLIVEIRA SILVA
  • DIMAS JOSÉ DA PAZ LIMA
  • Data: 29 juil. 2019


  • Afficher le Résumé
  • The interest in the synthesis of new bioactive molecules and the research for new methodologies according to the principles of Green Chemistry have been increased the last decades. 3-acyl-thioenaminones are densely functionalized intermediates with several reactive centers and they are important building blocks for several heterocyclic compounds, such as pyrazole, isothiazole and tetrazole. The aim of this work was to study green methodologies for synthesis of 3-acyl-thioenaminones and to investigate their reactivity to different nucleophiles and oxidant agent to develop a series of new molecules with biological activity. Two methodologies were developed for the synthesis of these compounds under solvent-free condition, low temperatures and solid support-free. The first methodology involved the reactions of enaminones with phenyl isothiocyanate under solvent-free condition at room temperature. The second methodology involved the same reaction condition under ultrasound irradiation. From the first methodology, it was possible to synthesize different 3-acyl-thioenaminones in yields of 18% and 78%. Most of reactions afforded a mixture isomeric 3-acyl-thioenaminones Z/E in the ratio 3:1. To investigate the reactivity of these compounds the 3-acyl-thioenaminones derivatives were synthesized from the mixture isomeric Z/E with hydrazine and iodine, with sodium azide only the isomer E was used. In the reaction with N2H4 80% in ethanol it was possible to obtain in one step the corresponding pyrazolone and pyrazole in 15% and 34% of yield, respectively. In the reaction with I2 and K2CO3 in acetonitrile the isothiazole was obtained in 17% of yield. In the reaction with NaN3 and Bi(NO3)3.5H2O in acetonitrile by microwave, 120°C, 150W and 5 min the tetrazole was obtained in 26% yield. The proposed methodology for the synthesis of 3-acyl-thioenaminone is according with the principles of Green Chemistry and it was developed with good yields. Among the 20 molecules synthesized in this work, nine are unpublished in the literature.

14
  • TAMIRES MARIEL MUNIZ MILHAZES
  • Ruthenium(II) base Schiff complexes: preparation, characterization, and evaluation as potential P450-bioinspired systems

  • Leader : LUCAS BOMFIM BOLZON
  • MEMBRES DE LA BANQUE :
  • LUCAS BOMFIM BOLZON
  • JOICY SANTAMALVINA DOS SANTOS
  • VALÉRIA PRISCILA DE BARROS
  • Data: 1 août 2019


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  • Brazil is one of the countries with the highest agrochemicals consumption, among which stands out the simazine, an herbicide of the triazine class. Besides it being harmful to directly exposed humans, this substance is also responsible for several damages to the environment, specifically to water sources. Therefore, it is necessary to research about the oxidation of this molecule, in order to provide a better base of toxicological profile, as well as to assist in the remediation of systems that are affected by this pesticide. In living systems, the superfamily of enzymes that perform the metabolism of exogenous molecules (pesticides, dyes and drugs) are the cytochromes P450. These monoxygenases perform the biotransformation of substrates in a fast, versatile and high effective way, that the use of synthetic model-systems that mimics the catalytic function of P450 has been studied over the past three decades. In this context, the objective of this work was to synthesize, characterize and evaluate the catalytic activity of P450 in ruthenium salen complexes against oxidation of simazine. For comparative effect, compounds of iron and manganese with salen were also synthesized, [RuNOCl(Salen-N(Et)2)], [MnCl(Salen-N(Et)2)], [FeCl(Salen-N(Et)2)], [RuNOCl(Salen-MeCl)] and [MnCl(Salen-MeCl)]. These coordination compounds were characterized by spectral techniques (FTIR and UV-Vis) and electrochemical (cyclic voltammetry). The analyzes indicated the efficiency of the complexation, as well as the high-transition states of the metals that possibly act in bioinspired oxidative reaction mechanism. The catalytic assays of these complexes in the simazine oxidation were performed with the respective oxygen donors: H2O2, PhIO, NaClO and m-CPBA and the oxidation products were separated by HPLC. The catalysts obtained satisfactory results in the substrate conversion, particularly for [Ru(Salen-MeCl)]/NaClO system which achieved 26.4%. Regarding to the product distribution, the most selective catalyst was the [Ru(Salen-N(Et)2)] since in the presence of all oxidants it was reached only two products.

15
  • ALBA DE OLIVEIRA DUTRA
  • SYNTHESIS OF FUNCTIONALIZED 1-AZADIENES DERIVATIVES OF ENAMINONAS VIA REACTIONS MULTICOMPONETES AND ITS EMPLOYMENT IN THE PREPARATION OF PIRAZÓIS
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • FERNANDA ANDREIA ROSA
  • MAURICIO MORAES VICTOR
  • SILVIO DO DESTERRO CUNHA
  • Data: 2 août 2019


  • Afficher le Résumé
  • 1-Azadienes are of great interest in organic synthesis because of their vast versatility in synthetic applications. This study brings innovative reactions to the methodology used to obtain 1-azadienes. Such methodology involves four reagents in two steps that are added in the one-pot way to the reaction medium (multicomponent reactions), so that the products formed incorporate structural characteristics of each of the reagents. Through this methodology, seven analogous azadienes were synthesized, resulting in four new ones to the literature. Still in the pseudo tetracomponent, three tetracyclic pyrazole compounds were synthesized. Obtaining different compounds demonstratesthe influence of the different substituents (activators and disactivants) on the diazonium salts, which are determinants for the final product. The azadienes synthesized by means that methodology were submitted to reactivity tests against oxidizing and reducing agents, in order to study possible synthetic transformations. The results were nitrogenous aromatic heterocycles of five members belonging to the azole class. In addition, trisubstituted and tetrasubstituted pyrazoles were synthesized in a novel way. This class of compounds is important because they belong to a set of molecules that, in addition to high medicinal potential, have a wide range of other applications, such as: pharmacological, agricultural, materials science and photographic.

16
  • JÉSSICA FRANÇA DE OLIVEIRA
  • Investigation of the electrochemical synthesis on the capacitive properties of RuO2 and RuO2-WO3 electrodes


  • Leader : ADRIANE VIANA DO ROSARIO
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • RAILDO ALVES FIUZA JUNIOR
  • ERNESTO CHAVES PEREIRA DE SOUZA
  • Data: 2 août 2019


  • Afficher le Résumé
  • Electrochemical capacitors have shown a myriad of advantages compared to conventional energy storage devices such as batteries and parallel plate capacitors. Studies have demonstrated that transition metal-based pseudocapacitors are the most promising electrochemical capacitors, as they exhibit high values of specific capacitance and extended life cycle. However, the high cost of ruthenium oxide, due to its sparse natural abundance, is its major drawback. On the other hand, tungsten oxide, whose capacitive properties have not yet been explored by the scientific literature, can feature as a pseudocapacitor component inexpensively. Understanding how the preparation variables influences the final characteristics of the oxides is crucial for the synthesis of increasingly efficient and effective materials. In this sense, factorial experimental design is a powerful tool. However, few are the studies which utilize this compelling approach in this specific field. This research intended to analyze the variables of preparation (scan rate, number of scans, and temperature of deposition) of ruthenium-tungsten mixed-oxide by cyclic voltammetry. This study was performed based on a 23factorial design using as a response factor the specific capacitance (Cs), and the maximum value obtained was of 236.5 Fg-1. The resolution of the factorial design revealed that the variables that most influence the specific capacitance values are, respectively, scan speed and number of cycles. Once the optimum conditions were found, the metal ions proportion in the electrolytic solution were studied and it was observed that the higher ruthenium oxide proportion, higher the specific capacitance values. However, electrodes prepared using a Ru/W molar ratio of 70/30 exhibited Cs values in the order of 300Fg-1, provin to be a very promising system for electrochemical capacitors applications.In the study of growth and nucleation by chronoamperometry from different electrolytic solutions the current transients indicated that the nucleation process occurs instantaneously on the substrate surface.

17
  • JAQUELINE REIS DE SOUZA BISPO
  • BIOREDUCTION AND OXIDATIVE KINETIC RESOLUTION OF OXYGENATED COMPOUNDS USING THE MARINE SPONGE Cliona varians
  • Leader : VALERIA BELLI RIATTO
  • MEMBRES DE LA BANQUE :
  • VALERIA BELLI RIATTO
  • JORGE MAURICIO DAVID
  • ADEMIR EVANGELISTA DO VALE
  • Data: 25 sept. 2019


  • Afficher le Résumé
  • Biocatalysis is an important tool in organic synthesis, especially in the synthesis of chiral molecules, due to the biological activity associated with these compounds. Brazil has a vast biological diversity, interesting from the biocatalytic point of view, which is still underused. The need to obtain chiral compounds through cleaner synthetic routes (Green Chemistry) makes important the controlled exploitation of fauna and flora, in order to develop new biocatalysts. In this work, the biocatalytic potential of the Cliona varians marine sponge was studied in stereoselective bioreduction reactions of pro-chiral ketone available in the laboratory (acetophenone, nitroacetophenone and acetylfuran) and in the oxidative kinetic resolution of racemic secondary alcohols chemically prepared [p-nitrophenylethanol, p-methoxyphenylethanol and 1-(2-furylethanol)]. To obtain racemic standards for comparison with the products obtained by the bioreductions, the ketones were reduced chemically (yields 75-97%). The reactional products were characterized by spectroscopic techniques (IV, 1H-RMN e 13C-RMN). The experiments were carried out by means of glucose and fructose as additives, and also when there were no additives. The biotransformation reactions were evaluated for 3, 5 and 7 days and analyzed through chiral CG. Hydroxylated products were obtained with moderate conversions and ee ranged from 20% to 84%, alternating the absolute R or S configuration depending on the additive employed.

18
  • TAHYANA MARA CHAGAS CARVALHO RANGEL
  • Oxidation of sulindac anti-inflammatory catalyzed by metal complexes as biomimetic and bioinspired models of 
    cytochrome P450

     
     
     
     
     
  • Leader : JOICY SANTAMALVINA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • JOICY SANTAMALVINA DOS SANTOS
  • ELIANE DE OLIVEIRA SILVA
  • VALÉRIA PRISCILA DE BARROS
  • Data: 28 nov. 2019


  • Afficher le Résumé
  • Cytochrome P-450 (CYP) enzymes are present in all living organisms and participate of phase I metabolism of drugs, pollutants and other xenobiotics. A more practical, economical and ethical way to study these enzymes metabolites can be done through the use of biomimetic and bioinspired catalysts, structurally similar to CYP enzymes, instead of in vitro / in vivo methods. In this work we studied the sulindac drug oxidation (a non-steroidal anti-inflammatory used for the treatment of rheumatoid arthritis) using biomimetic and bioinspired catalysts: metalloporphyrins, metallosalens (Jacobsen isomers) and cyclam (tetraazocycletretradecane) with iron centers. (III) and manganese (III). Iodosilbenzene, hydrogen peroxide, meta-chloroperbenzoic acid and sodium hypochlorite were used as oxygen donors for the reactions. All reactions were analyzed by high performance liquid chromatography (HPLC). The catalysts used in this study were efficient in sulindac oxidation and better yields (38.2%) was achieved by the system using FeCyclam with NaClO at 1:40:400 molar ratio, followed by FeTFPP and NaClO system at the same molar ratio (31.1%). Good system conversions were observed using Cyclam and NaClO catalysts as oxidant. The results of catalytic studies mediated by biomimetic / bioinspired systems were compared to those obtained by sulindac biotransformation using the fungus Cunninghamella elegans. Oxidation products obtained by biotransformation were separated by classical column chromatography and analyzed by 1H and 13C NMR, and compared to results obtained by biomimetic catalysis. It was possible to separate only one of the biotransformation products, named P7 herein, and identified as 2-(5- fluoro -1(hydroxy-(4-(methylsulfinyl)phenyl)methyl)-2-methyl-1H-inden-3-yl)acetic acid. This compound was also confirmed as a sulindac oxidation product for biomimetic reactions using Fe/ MnCyclam and NaClO.

19
  • ADALBERTO SANTANA LIMA JUNIOR
  • Low-lying electronic states of SiF+ specie

  • Leader : TIAGO VINICIUS ALVES
  • MEMBRES DE LA BANQUE :
  • TIAGO VINICIUS ALVES
  • ROBERTO RIVELINO DE MELO MORENO
  • CLAUDIO HANASHIRO BARBOSA SILVA
  • ANTONIO GUSTAVO SAMPAIO DE OLIVEIRA FILHO
  • Data: 29 nov. 2019


  • Afficher le Résumé
  • In this study, the structural, energetic and spectroscopic parameters of the low-lying electronic states (Λ + S) of the SiF+, correlating with the two lowest dissociation channels [Si+(2Pu) + F(2Pu) e Si+(4Pg) + F(2Pu)], were obtained at MRCI+Q/aug-cc-pV5Z theory level. At this level, the energy difference between these dissociation channels (41145 cm-1), corresponding to excitation Si+(2Pu) - Si+(4Pg). Of the twelve states that correlate with the first dissociation channel, eight of them are stable, (X 1Σ+, 1 3Π, 1 3Σ+, 1 3Δ, 1 1Δ, 1 1Σ-, 1 3Σ+, 2 1Σ+), while for the second channel, only five states were show to be energetically stable, (3 3Π, 1 5Π, 2 3Σ+, 4 3Π, 3 3Σ+). For the ground electronic state (X 1Σ+), the internuclear distance (Re) and vibrational frequency (𝜔e), at MRCI+Q/aug-cc -pV5Z, were 2,891 a0 and 1,043 cm-1, respectively. For the first excited state, (1 3Π), these values were 2,929 a0 and 981 cm-1, respectively. The values obtained in this study are in excellent agreement with previous theoretical and experimental studies. Based on the accurate description of these states, this work provides the structural, energetic and spectroscopic parameters for the first time in the literature, for the electronic states correlated with the second dissociation channel.

20
  • NATHALIA EVELYN MORAIS COSTA
  • Synthesis of 2-AMINO-1,4-Naphthoquinone-derived Penta-Heterocycles Through Formal [3 + 2] and [3 + 2 + 1] Promoted Azoric Acids

     
     
     
     
     
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • ANDRE ALEXANDRE VIEIRA
  • FERNANDO DE CARVALHO DA SILVA
  • Data: 12 déc. 2019


  • Afficher le Résumé
  • Nitrogenous heterocycles are substances of great importance their biological properties and also for being present in highly consumed substances worldwide. As regarding to this, a great deal of effort has been placed on the synthesis of new compounds, mainly nitrogenous multicycles, once that these products have complex nuclei, with different chemical and biological functions. In this work, was synthesized nitrogen heterocycles from formal azaannulation reactions [3 + 2] and [3 + 2 + 1] that constitute an efficient and versatile protocol for the formation of multiple bonds with step reduction, and production of by-products, making this synthetic route an alternative incorporated into Green Chemistry. An important building block os nitrogen heterocyclic is enaminones, which this work were limited to the 2-amino-1,4-naphhoquinones type. Enaminones are densely functionalized and that are easily obtainable, and have dual reactivity which can act as electrophile or nucleophile, a characteristic that makes it interesting from a synthetic point of view. In this work, the employed enaminones act as nucleophiles and its reactivity was tested against aromatic aldehydes and ninhydrin leading to linear pentacycles, isocoumarins and dihidroxylated pyrols. In order to optimize the synthesis of aza-pentacenotetraones from 2amino-1,4-naphthoquinone and aromatic aldehydes, a study of reactions promoted by organic diacids, and a solvent study was carried out. Fourteen products were isolated with yields between 32 and 97%, among them eight unpublished. N-substituted 2-amino-1,4-naphthoquinones reactivity to ninhydrin is also investigated. In this case, it was possible to isolate two distinct nuclei: isocoumarins and dihydroxylated pyrrols, both in a microwave reactor. Studying the synthesis of isocoumarins made, it was possible to isolate them in yields between 45 and 99%, even with a small amount of catalyst. Also, it was possible to isolate 10 products, among them four unpublished. Dihydroxylated pyrroles were isolated with yields between 30% and quantitative, without catalyst. Eleven products were isolated which all are unpublished. On the reactivity of 2-amino-1,4-naphthoquinones it was possible to show a reactivity sensitive to the reaction medium. In addition, all isolated nuclei exhibit therapeutic potential described in the literature.

21
  • FERNANDO ALVES BARRETTO
  • Synthesis of coumarins, benzofurans, itaconimides, and coumarin-itaconimide hybrids using the Wittig reaction of phosphorus ilids derived from maleic anhydride

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • ELIANE DE OLIVEIRA SILVA
  • CECILIA MARIA ALVES DE OLIVERA
  • Data: 16 déc. 2019


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  • The main purpose of this scientific research is to evaluate the reactivity of α- triphenylphosphoranylidene-succinic anhydride and triphenylphosphoranylidene-pyrrolidine against dicarbonic electrophiles to obtain coumarins, benzofurans, itaconimides and coumarin-itaconimide hybrids. Using Wittig reaction, with phosphorus ilide (83) and furfuraldehyde (74), was possible verify formation of alkene (76), which cannot be isolated due to its instability. Thereby, the mixture of (76) and triphenylphosphine oxide was submitted in condition of acetic anhydride and sodium acetate for 15 hours at room temperature. After this period, the reaction medium was subjected to reaction in the microwave reactor under the following conditions: 16 min, 100 °C, 200W, 250psi, obtaining benzofuran (77a) in 95% yield for two steps. Basic hydrolysis of (77a) drove benzofurans (77b) and (78). Aryl itaconimide and coumarins can be obtained from three-component synthesis at room temperature, and MeOH employing N- arylmaleimides (86a-e), salicylaldehydes (88) and triphenylphosphine. In this research, it was possible accessed a series of E-itaconimides and coumarins (89a-i), with 28-89% yields. When was employed the coumarins 112(a, b) in phosphorus ilides 87(ba-dc) in EtOH and reflux for a period of 15-22 hours, coumarin-itaconimide hybrids 113(a) and 114(a,c) were obtained. The compound (113a) was obtained in 62% yield and compounds 114(a-c) in 10- 18% yield. Therefore, a new synthetic methodology for obtaining benzofurans compounds was developed by Wittig reaction. New coumarins-itaconimide hybrids and coumarins were obtained using the threecomponent synthesis of maleimides, salicylaldehyde and triphenylphosphine derivatives by in situ Wittig reaction.

22
  • JOSE ROGERIO SOUZA DA SILVA
  •  

    OPTIMIZATION OF METHODOLOGY FOR DETERMINATION OF INORGANIC CONSTITUENTS IN QUAIL EGGS USING ICP OES


  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • RODOLFO DE MELO MAGALHAES SANTANA
  • Data: 19 déc. 2019


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  • In the present work, an analytical method was optimized for the determination of inorganic constituents in quail eggs using the optical emission spectrometry with inductively coupled plasma (ICP OES). To optimize the conditions of the sample preparation and operational procedures of the spectrometer, three-level experimental planning was applied, based on the Box Benhken and Doehlert models, respectively. The sample preparation was established using diluted nitric acid, being suitable for conception of Green Chemistry. The proposed analytical method proved to be sensitive for the determinations of Ba, Ca, Cu, Fe, K, Mg, Na, P, S, Sr and Zn in quail eggs. The limits of quantification (LoQ) obtained varied between 7 ng g-1 (Ba) and 28 µg g-1 (S). Accuracy of the analytical method was confirmed through the analysis of certified reference materials of bovine muscle (NIST 8414) and egg powder (NIST 8415), obtaining agreement values between 81.60 ± 0.10% and 97.50 ± 0 , 01% for NIST 8414 and 80.0 ± 0.3% and 108.1 ± 0.04% for NIST 8415 respectively. Precision was expressed as relative standard deviation (RSD), being less than 9% (Ca, n = 3). The proposed methodology was applied to the analysis of 30 samples of quail eggs. For macroelements concentrations (Ca, K, P, Mg, Na and S) found varying between 319 ± 9 µg g-1 (Mg) and 8643 ± 218 µg g-1 (P). The microelements and trace elements, Ba, Cu, Fe, Sr and Zn, had their concentrations varying between 4.21 ± 0.26 µg g-1 (Sr) and 65.5 ± 9.7 µg g-1 (Fe) . Multivariate data analysis was applied in order to characterize the quail egg samples in terms of their chemical composition, where it was observed that they did not present a separation into different groups according to the elementary compositions. However, compared to chicken eggs, quail eggs showed higher concentrations for Ca, K, Na, P, S and Zn, representing up to 23% of the recommended digestion index (IDR), established for calcium.

23
  • TALITA MARIA SILVA DE SOUSA
  • SYNTHESIS STUDY OF PEROVSKITA LaNiO3 TYPE CATALYTIC PRECURSORS SUPPORTED IN SiO2 APPLIED IN DRY REFORMING OF METHANE 

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • SORAIA TEIXEIRA BRANDAO
  • ROBERT NEWTON DA SILVA HENRIQUES MAGALHÃES
  • ANDRE ROSA MARTINS
  • Data: 20 déc. 2019


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  • Unsupported and SiO2 supported Perovskite catalytic precursors were prepared by the citrate method, wet impregnation and as a proposal of this work, single step synthesis with addition of the support in the citrate route. Subsequently, they were characterized by TG, FTIR, XRD, BET, BJH, SEM, MET, TPR-H2 and evaluated in dry reform of methane. XRD results indicated that the citrate route was satisfactory to obtain the desired perovskite phase and the diffractograms of the reduced samples showed the Ni/La2O3 catalyst formation, and for the supported Ni/La2O3/SiO2 samples. It was verified by the average size of the crystallite that the support promoted the reduction of the metallic phase. Scanning and transmission electron microscopy and surface area and porosity results indicated that the difference in synthesis between the supported materials generated different distributions of the precursors in the support as well as different particle sizes. The results of TPR –H2 showed the significant effect of the synthesis method and the presence of the support under Ni reduction. All catalysts studied were active for methane dry reforming with reaction temperatures below the homogeneous phase. The effect of the support on reducing the activation energy of the reagents, with reaction temperatures lower than the unsupported sample, was also highlighted. The singlestage synthesized sample showed the best results for reagent conversion and product yields, in addition to the near-stoichiometric H2/CO ratio. In addition, the TPO results also indicated the efficiency of this catalyst, due to the 50 times lower carbon formation compared to the reference sample, suggesting that the synthesis method proposed by this work made it possible to obtain a material with high homogeneity and with particle size and surface area, suitable for catalytic activity.

Thèses
1
  • GECIANE ALVES DOS SANTOS
  • EFFECT OF MAGNESIUM AND IRIDIDE ON PROPERTIES OF NICKEL AND COBALT CATALYSTS OBTAINED FROM FROM PEROVSKITA

  • Leader : MARIA DO CARMO RANGEL SANTOS VARELA
  • MEMBRES DE LA BANQUE :
  • ANDRE ROSA MARTINS
  • CESÁRIO FRANCISCO DAS VIRGENS
  • HUMBERVÂNIA REIS GONÇALVES DA SILVA
  • LUIZ ANTONIO MAGALHAES PONTES
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • Data: 21 janv. 2019


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  • The limitation and dependence of energy sources are stimulating environmental awareness, thus promoting the search for alternatives to energy from renewable and sustainable sources, such as wind energy and solar energy. In addition, there is growing interest in the production of biofuels from biomass, such as bioethanol, as an attractive source for the production of biohydrogen, which can be used both as a fuel and in internal combustion engines. The construction of the energy vector depends on factors such as the production method and the use of catalysts. The main catalysts are based on nickel, cobalt, copper, platinum, copper oxide, aluminum oxide, aluminum oxide, nickel oxide and nickel oxide. However, the study of the properties of the catalysts is necessary, since the use of catalysts influences the production of plants and nutrients of hydrogen and carbon dioxide (reform products). In this work, the effect of magnesium and iridium on the properties of nickel and cobalt catalysts supported on lanthanum oxide from perovskites, as prepared by the Pechi method, was analyzed. On the other hand, the catalysts were prepared by reducing the concentrations of hydrogen peroxide (1% w/w). After impregnation, the catalysts were reduced and then passivated. Thus, nickel, cobalt and / or iridium catalysts supported on lanthanum oxide (containing magnesium oxide or not) were added. The membranes were characterized by thermogravimetry, Fourier transform infrared spectroscopy, X-ray diffraction, surface measurement, programmed temperature reduction, ammonia desorption and programmed temperature and catalytic evaluation. All catalysts were active and selective in the steam reforming of ethanol. The addition of magnesium contributed to higher yield values for the catalyst containing lanthanum and nickel. While the catalyst contains the largest mole fraction values for products such as hydrogen and carbon dioxide. The addition of iridium positively influenced the stability of the catalysts; In addition, it led to higher values of yield and selectivity

2
  • CARLOS ALBERTO GOMES DE SOUZA
  • REMOVAL OF PHENOL IN AQUEOUS EFFLUENTS ON IRON OXIDE CATALYSTS SUPPORTED IN ACTIVATED CHARCOAL
  • Leader : MARIA DO CARMO RANGEL SANTOS VARELA
  • MEMBRES DE LA BANQUE :
  • ALEXILDA OLIVEIRA DE SOUZA
  • HUMBERVÂNIA REIS GONÇALVES DA SILVA
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • SERGIO TELLES DE OLIVA
  • SORAIA TEIXEIRA BRANDAO
  • Data: 23 janv. 2019


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  • Advanced Oxidative Processes (AOPs), where hydrogen peroxide is combined with a heterogeneous catalyst, have been established as one of the most promising alternatives for the removal of organic pollutants from aqueous effluents, especially phenols. Among the AOPs, Fenton reaction has been pointed out as one of the most efficient ones. Aiming to develop catalysts more efficient than those describe in literature, as well as to decrease the industrial and agriculture wastes in the environment, catalysts based on iron oxide supported on activated carbons obtained from lignocellulosic and of polymeric materials, to the removal of phenols from aqueous streams, through by oxidation with hydrogen peroxide. Activated carbons were prepared by carbonization/activation of flamboyant pods (agricultural wastes) and Amberlyst-15 polymeric resin (industrial waste), using steam, magnesium chloride, iron nitrate as activators, followed by functionalization with sulfuric acid and nitric acid and impregnated with iron nitrate solutions. Samples were characterized by thermogravimetry, Fourier transform infrared spectroscopy, Raman spectroscopy, X- ray diffraction, specific surface area and porosity measurements, apparent density measurements and scanning electron microscopy. The obtained samples were evaluated in phenol removal by Fenton reaction at room temperature. It was observed that the two precursors were suitable for the production of activated carbons. For all cases, activation led to a significant increase of specific surface area, except for activated carbon obtained with iron nitrate from the polymer resin. The physical activation favored the formation of pores in the activated carbon, while the acid functionalization promoted a significant destruction of pores and, consequently, a decrease of the specific surface area. The incorporation of iron in the supports led to the production of catalysts based on iron oxides (magnetite and hematite) supported on activated carbons. The catalysts activated with magnesium chloride, iron nitrate and steam were able to remove phenol by Fenton reaction; most of them were more active in the reaction, showing low adsorptive capacity. On the other hand, the iron oxide catalyst obtained through pod and activated with steam was the most efficient for phenol removal, being the most promising to degrade organic compounds in industrial effluents, decreasing environmental problems.

3
  • Alessandra Tanajura Campos
  • DEVELOPMENT AND VALIDATION OF A METHOD FOR PREDICTING SULFUR CONTENT IN DIESEL BIODIESEL MIXTURES BY SPECTROFLUORIMETRY AND MULTIVARIATE CALIBRATION WITH ROBUSTNESS IN OXIDATIVE FUEL DECAY

  • Leader : CRISTINA MARIA ASSIS LOPES TAVARES DA MATA HERMIDA QUINTELLA
  • MEMBRES DE LA BANQUE :
  • CRISTINA MARIA ASSIS LOPES TAVARES DA MATA HERMIDA QUINTELLA
  • JOICY SANTAMALVINA DOS SANTOS
  • ELIAS RAMOS DE SOUZA
  • IDALIA HELENA SANTOS ESTEVAM
  • WAGNA PILER CARVALHO DOS SANTOS
  • Data: 24 janv. 2019


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  • The use of sustainable fuels has a high value in the current global energy configuration. However, the presence of sulfur in diesel is a point that has a great environmental concern, because high concentrations of the element, can cause several damages. The present work had the objective of developing and validating a method to predict sulfur content in biodiesel-diesel blends, usingspectrofluorimetry and partial minimum squares methods. Before starting the work, a review of prior, significant literature was carried out in order to identify studies related to the topic, facilitate theory development as well as "technological bottlenecks". The methodology for determining the sulfur content consisted of the preparation of biodiesel blends in diesel and biodiesel oxidized in diesel with different sulfur contents, which cover the limits set by the National Petroleum Agency and in the characterization of the samples by infrared spectroscopy and. Subsequently, the multivariate calibration curves were constructed as a function of the sulfur concentration and using its Sulfur in Di-n-Butyl Sulfide standard through the data obtained in the x-ray fluorescence and fluorescence induced by light emitting diode. The same samples were used to perform the correlation of the reference method (Xray fluorescence), consistent with the standard ABNT NBR 14533, and the new method proposed using the equipment Quimisspectrofluorimeter Q798FIL. The multivariate calibration models obtained low deviations, being around 0.33845 and 1.5045 for B10 and B20, in this order, with addition of sulfur standard obtained in the reference equipment, and for the proposed method was 0.9791 for B10 and 0.6046 for B20. On the other hand, with addition of elemental sulfur, mean standard deviation of 0.3771 and 2.727 (X-ray fluorescence) and 0.3644 and 0.9587 (light emitting diode induced fluorescence) were obtained for B10 and B20, respectively. The addition of elemental sulfur provided a suitable correlation for B10 (R2 of 0.9633) and for B20 (R2 of 0.9745) as well as the addition of its standard for B10 (R2 of 0.9903) and for B20 (R2 of 0.9590). According to the t and F hypothesis tests it was concluded that the proposed method (fluorescence induced by light-emitting diode) meets the proposed objective, presenting also further advantages such as cost, speed of analysis and simplicity.

4
  • Maria Antonieta Pereira de Almeida Santiago
  • DEVELOPMENT AND APPLICATION OF ANALYTICAL METHOD MULTI-RESIDUE BY LPME/GC-MS FOR THE DETERMINATION OF PESTICIDES IN RED WINE SAMPLES
     
     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • HAROLDO SILVEIRA DOREA
  • GISELE OLIMPIO DA ROCHA
  • JAILSON BITTENCOURT DE ANDRADE
  • LILIAN LEFOL NANI GUARIEIRO
  • WILSON ARAUJO LOPES
  • Data: 5 févr. 2019


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  • The conventional cultivation of grapes for wine production is characterized by the use of a number of different pesticide groups, in which the group that finds the greatest application are the fungicides. Some classes of pesticides are resistant to the fermentation process, which results in their presence in the final product, affecting wine quality and consumer health. The routine methods used in the analysis of pesticide residues generally require a large amount of time and of organic solvents due to the steps involved in preparing the sample prior to the chromatographic analysis. The aim of the present study was to present the steps involved on the development a simple, efficient and low solvent consumption method for the determination of 17 pesticides of different classes (including organophosphorus pesticides, organochlorine, pyrethroid and acaricide) in red and rosé wine, using liquid phase microextraction with a binary solvent mixture (BS-LPME). Extraction parameters, including type and volume of the extraction solvent, salinity, stirring time, extraction time and volume of wine were tested. Once the final extraction conditions were established, the procedure was evaluated in terms of its merit figures: selectivity, linearity, precision, accuracy, limits of detection and quantification. The correlation coefficients between 0.9987 and 0.9999 were obtained by means of matrix equalization using the analytical curves, indicating a good linearity for the working conditions. The limits of detection and quantification ranged from 0.044 to 0.233 μg L-1 and 0.294 to 0.777 μg L-1, respectively. The analytical method was applied to 14 red and rosé wine samples from different origins. The presence of the demeton-o, methylparathion, malathion, dursban and azoxystribin pesticides was found in concentrations ranging from levels below the detection limit up to 24.8 μg L-1 (dursban). The results showed that the method proved to be efficient for the simultaneous identification and quantification of 17 pesticides. Its advantages are the simplicity and the possibility of application in colored and/or turbid samples.

     
     
5
  • VANESSA DE SOUZA SANTOS
  • EVALUATION OF THE DISTRIBUTION OF ESSENTIAL AND POTENTIALLY TOXIC ELEMENTS IN SAMPLES OF GRAPE MUST AND SOIL OF THE REGION OF THE SÃO FRANCISCO SUBMEDIO.
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • KARINA SANTOS GARCIA
  • MARCOS DE ALMEIDA BEZERRA
  • MARIA DAS GRACAS ANDRADE KORN
  • MARIA ELISABETE MACHADO
  • RODOLFO DE MELO MAGALHAES SANTANA
  • Data: 8 févr. 2019


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  • The city of Petrolina/PE, located in the Submédio São Francisco produces grapes year-round, destined for both the domestic and international markets. However, content information of essential and potentially toxic elements in grape must in this local is limited. The objective of the present work was to evaluate the distribution of essential and potentially toxic elements in samples of grape must (Al, As, Ca, Cu, Fe, K, Mg, Mn, Se and Zn) and in vineyard soil (Co, Cu, Fe, Mn, Ni, V, Pb and Zn) using inductively coupled plasma optical emission spectrometry (ICP OES), in order to establish a profile of the different types of grapes produced in Petrolina / PE. The decomposition with diluted acid assisted by microwave was proposed for grape must and were analyzed seven grape varieties (Italy Moscato, Italy Melhorada, Arra-15, Scarlotta, Crimson, Benitaka and BRS Isis). The decomposition procedure for grape must had low reagent consumption (1 mL of HNO3 and 1 mL of H2O2), low dissolved organic carbon (<2% m v-1) and low residual acidity (0.8 mol L-1) compared to others procedures described in the literature. The method was validated with good precision (RSD <7%), low LOQ (0.03 to 2.7 mg L-1) and the accuracy of the method was verified through addition and recovery tests, with recovery variation of the elements of 81 ± 0.1 to 119 ± 0.8%. The concentration ranges, in mg L-1, for the analytes in the samples of grape must were: Al (0.8 ± 0.2 - 8.4 ± 0.6), As (0.30 ± 0.03 - 0.51 ± 0.08), Ca (45.9 ± 0.7 - 115, 6 ± 3,3), Cu (0.06 ± 0.01 - 3.03 ± 0.05), Fe (0.50 ± 0.04 - 6.1 ± 0.1), K (718 ± 48 - 1833 ± 4) Mn (0.06 ± 0.01 - 0.33 ± 0.04), Mg (35.5 ± 7.8 - 122.4 ± 0.8), Mn (0.6 ± 0.01 - 0.33 ± 0.04), Se (0.6 ± 0.1 - 1.02 ± 0.28) and Zn (0.10 ± 0.04 - 0.90 ± 0.02). There was no significant difference between the concentrations of the elements of the grape must samples and the values of the Brazilian food composition table (TACO), applying t test, at the 95% confidence level. Samples of Scarlotta and Arra-15 grape must showed higher concentrations of As than LMT by the MERCOSUR technical regulation and Se levels above the ANVISA LMT. Soil samples from grapevine cultivation were analyzed after application of the decomposition procedure of the Environmental Protection Agency, EPA 3051a. The method was validated through accuracy with analysis of certified reference material (NIST 2709a), recovery of elements (80 ± 0.5 to 119 ± 1.3%), precision (RSD <9%) and LOQ (0.4 to 3.8 µg g-1). The concentration ranges, in µg g-1, for the analytes in the soil samples were: Co (0.9 ± 0.2 - 30.1 ± 4.9), Cu (2.2 ± 0.6 - 69.4 ± 0. 9), Fe (2755 ± 30 - 18122 ± 90), Mn (50.8 ± 6.3 - 650 ± 90), Ni (2.7 ± 0.5 - 65.3 ± 3.9), V (6.4 ± 0.6 - 36.9 ± 1.5 ), Pb (3.2 ± 0.1 - 20.7 ± 2.7) and Zn (14.5 ± 2.5 - 154.3 ± 4.8). None soil sample exceeded the stipulated value for intervention in agricultural soils based on resolution 420/2009 of CONAMA. By constructing a regional geochemical basis, calculation the enrichment factor and the geoacumulation index in the soil samples, it was possible to verify that some points investigated presented significant enrichment and moderate to strong contamination for Ni and Cu contents. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied in the results in order to evaluate the main influences of the variables in the grape must and soil samples and allowed to establish a preliminary profile for each variety of grapes and differentiate the soil sample per farm. In addition, the results obtained in this work contribute to the table of mineral composition of foods, since they bring unpublished information of essential and potentially toxic elements in must sample of seven grape varieties grown in the Submédio São Francisco.

6
  • LETICIA DE ALENCAR PEREIRA RODRIGUES
  • DETERMINATION OF TRANS FATTY ACIDS BY GAS CHROMATOGRAPHY IN EDIBLE VEGETABLE OILS AFTER HEATING IN THE PRESENCE OF METAL IONS
  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • JORGE MAURICIO DAVID
  • ADRIANA COSTA FERREIRA
  • WILSON ARAUJO LOPES
  • HILDA COSTA DOS SANTOS TALMA
  • Data: 14 févr. 2019


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  • Frying is one of the most widely used cooking methods in the world and has been reported as a process that increases the production of trans fatty acids (TFA). The formation of TFA occurs through the cis-trans isomerization process of the unsaturated fat, which can be favored in the presence of metallic ions and at temperatures above 180°C. The objective of this work was to evaluate the formation of trans fatty acids in samples of soybean and canola oils at typical heating temperature (180 ± 5)°C in the presence of copper and iron ions over 24 h of heating. To quantify the trans fatty acids in the oil before and after heating, the alkaline transesterification was optimized, followed by the validation of the method using gas chromatographic analysis with flame ionization detector (GC-FID). The optimization of the transesterification was performed in a univariate manner and, under the recommended conditions, the following factors were used: concentration of KOH methanolic solution at 2,0 mol L-1 , stirring time of 40 s, volume of the saturated solution of 3,0 mL NaCl and n-heptane solvent. In the validation of the chromatographic method the limits of detection and quantification, linearity, precision and accuracy were evaluated. The Cu and Fe contents were quantified in the oils before heating, and values compatible with the literature were found, revealing the contamination of origin. For the soybean oil it was observed that in the heating experiments without addition of metals there was formation in g/100g of C18:1, 9t; C18:2, 9c 12t; C18:2, 9t 12c and C18:3 trans in 24 h of, respectively: 0,10±0,02; 0,38±0,02; 0,36±0,02 and 0,92±0,01. For canola oil the formation in g/100g of C18:1, 9t; C18:2, 9c 12t; C18:2, 9t 12c and C18:3 trans was, respectively: 0,31±0,04; 0,23±0,02; 0,24±0,02 and 1,25±0,02. In the study of the influence of the metals Cu and Fe in the concentration of 10, 30 and 50 μg kg1 of oil, in general, the addition of the metal ions in the samples caused an increase in the concentrations of the trans fatty acids. In terms of the catalytic effect, iron was the metal that proved to be more efficient in promoting an increase in the concentrations in relation to copper, and, in general, these effects were higher in the concentration of 50 μg kg-1 . The results of the present work are of great importance for the society in general as it addresses the problems related to the formation of TFA in oils when submitted to heating. Copper and iron metals may be present in utensils and containers and generate increased TFA formation during heating.

7
  • LAÍS ARAÚJO SOUZA
  • Evaluation of in vitro bioaccessibility of essential elements in food samples: comparison of static and dynamic methods
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MADSON DE GODOI PEREIRA
  • MANUEL MIRÓ
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • VALFREDO AZEVEDO LEMOS
  • WAGNA PILER CARVALHO DOS SANTOS
  • Data: 27 mars 2019


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  • Given the importance of knowing the nutritional value of linseed and sesame, the main objective of this study was to compare the different in vitro methods SBET (Simple Bioaccessibility Extraction Test), UBM (Unified Bioaccessibility Method) and Versantvoort and to develop an automatic flow-through dynamic extraction system is proposed for in-vitro exploration, with high temporal resolution, of the transit of the chyme from the gastric to the duodenal compartments using the Versantvoort’s fed-state physiologically relevant extraction method., to evaluate the bioaccessibility of micronutrients. Among the in vitro methods investigated, UBM was selected and The highest bioaccessible fractions, in %, in gastric phase were observed for Mn (19–27%) and Zn (16–25%). In addition, it was found through the application of in vitro simulated gastrointestinal digestion that only a minor fraction of total Fe and Cu was potentially bioaccessible in this samples. The flow manifold was coupled on-line to an inductively coupled plasma optical emission spectrometer for real-time elucidation of the bioaccessible elemental fraction of micronutrients (Cu, Fe and Mn) in food commodities across the gastrointestinal tract. The simulated intestinal and bile biofluid (added to the gastric phase) was successively pumped at 1.0 mL min-1 through a large-bore column (maintained at 37.0 ± 2.0 °C), initially loaded with about 250 mg of linseed, using a Polyvinylidene fluoride (PVDF) filter membrane (5.0 µm pore size) for retaining of the particulate matter and in-line filtration of the extracts. The lack of bias (trueness) of the on-line gastrointestinal extraction method coupled to ICP OES was confirmed using mass balance validation following microwave assisted digestion of the residual (non-bioaccessible) elemental fraction. Mass balance validation yielded absolute recoveries spanning from 79 to 121% for the overall analytes and samples. On-line dynamic extraction was critically appraised against batch counterparts for both gastric and gastrointestinal compartments. The bioaccessibility of the chime, in the dynamic extraction, ranged from 21-30% (Cu), 6-7% (Fe) and 21-22% (Mn), already in batch extraction ranged from 42-58% (Cu), 17-52% (Fe) and 24-37% (Mn). Due to the lack of consensus in the literature regarding the agitation method in batch oral bioaccessibility testing, several extraction approaches (viz., magnetic stirring, end-over-end rotation and orbital shaking) were evaluated. While orbital shaking and end-over-end rotation approaches the gastric bioaccessibility of Fe <17 mg kg-1, magnetic stirring provided higher bioaccessibility, 31.9 ± 0.4 mg kg-1. To the best of our knowledge, this is the firt thesis reporting a fully automatic dynamic GI extraction method.

8
  • VALDINEI SANTOS DE SOUZA
  • DETERMINATION OF METAL SPECIES IN SAMPLES OF INTEREST OF THE OIL INDUSTRY USING MICELARIAN SYSTEMS AND ATOMIC ABSORPTION ATOMIZATION SPECTROMETRY

     
     
     
     
     
     
  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • ERIK GALVÃO PARANHOS DA SILVA
  • ICARO THIAGO ANDRADE MOREIRA
  • LEONARDO SENA GOMES TEIXEIRA
  • MARCOS DE ALMEIDA BEZERRA
  • MARIA DAS GRACAS ANDRADE KORN
  • WALTER NEI LOPES DOS SANTOS
  • Data: 28 mars 2019


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  • In this work, analytical strategies were developed for the determination of metallic species in samples of interest of the oil and gas sector using cloud point extraction (CPE) or emulsion-induced extraction (EIEB) as sample preparation procedures and spectrometric analysis of atomic absorption with graphite furnace (GF AAS). In the first stage of the work, a patent mapping was carried out in order to evaluate the current scenario and the technological and scientific maturity associated to the determination of vanadium and other species in oil and its derivatives. This search showed that there is a low technological production using vanadium as an element of research, which is a propitious field for the development of scientific and technological research with high potential for innovation. In the second stage, chemometric techniques with multivariate approaches were applied in the optimization of a method of extraction at the cloud point for the determination of vanadium in groundwater collection of tubular wells at fuel stations and surface waters of dams. The method was successfully applied and concentrations in the range of < LOQ to 2.0 μg L-1 were found for the samples collected at fuel stations and from 1.28 to 11.56 μg L-1 for surface water. The limits of detection (LOD) and quantification (LOQ) were 0.13 and 0.42 μg L-1, respectively, and analyte addition and recovery tests presented results between 84 and 122%. The third step involved the determination of vanadium, copper, and nickel in gasoline type C samples using the EIEB. Concentrations in the range of < LOQ to 15.8 μg L-1, 8.9 to 31.9 μg L-1 and < LOQ to 9.8 μg L-1 were found for V, Cu, and Ni, respectively. LOD was estimated at 2.0, 0.6, 0.7 μg L-1 while LOQ were 7.0, 2.0 and 2.3 for V, Cu, and Ni, respectively. The recoveries were between 82 and 130% for all metals. A new strategy was adopted for the determination with speciation of the volatile and non-volatile fractions of Ni and V in the common gasoline. The EIEB procedure was optimized to allow the determination of the analytes in GF AAS. The furnace conditions were also studied and temperatures of 300 and 200 °C were used in the pyrolysis step in the presence of Pd(NO3)2 modifier for the determination of the total contents of V and Ni, respectively. The thermostable fractions were determined without the use of modifier at higher pyrolysis temperatures: 1700 and 1500 °C for V and Ni, respectively. For the vanadium, the LODs, precision (% RSD, n = 8, 10 μg L-1) and recovery values were 1.1 and 0.42 μg L -1, 5.8 and 3.4% and 96-108 and 100-108% for the total content and nonvolatile fraction, respectively. For the nickel, the LODs, precision (% RSD, n = 8, 10 μg L-1) and recovery values were 3.5 and 1.7 μg L-1, 9.6 and 2.0% and 86-101 and 91109% for the total content and non-volatile fraction, respectively. Enrichment factors between 2.5 and 5.0 times were found for both metals. This method was applied in the determination of the total contents: 3.70 - 31.98 and 15.71 - 126.1 μg L-1, of the nonvolatile fractions: 2.16 - 14.33 and 2.00 - 10.99 μg L-1 and of the volatile fractions: 1.54 - 20.54 and 13.71 - 115.1 μg L-1 of vanadium and nickel, respectively, in samples of ordinary gasoline. The methods developed in this work, present adequate analytical characteristics, such as; precision, accuracy, sensitivity, fastness and low waste production for the determination of metals in samples of petroleum industry interest using GF AAS.
     
     
9
  • SIDNEI DE OLIVEIRA SOUZA
  • ANALYTICAL STRATEGIES USING CHEMIOMETRIC TOOLS FOR ANALYSIS OF HUMAN CONSUMPTION FOOD AND ANIMALS USING SPECTROMETRIC TECHNIQUES
     
  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • RODOLFO DE MELO MAGALHAES SANTANA
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MARIA DAS GRACAS ANDRADE KORN
  • SARAH ADRIANA ROCHA SOARES
  • FABIO DE SOUZA DIAS
  • VICTOR CERDÀ MARTÍN
  • ADRIANO DE ARAÚJO GOMES
  • CLEBER GALVAO NOVAES
  • TATIANE DE ANDRADE MARANHÃO
  • Data: 26 avr. 2019


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  • In this work, three works were developed involving strategies for food analysis for determination of inorganic constituents in animal feeds and sugarcane juice samples, as well as, chemical speciation analysis of As, Sb and Se of dried fruits using atomic spectrometry. In the first work, simultaneous experimental designs were applied to optimize the conditions of microwave-assisted sample decomposition and operational of a spectrometer for animal feed analysis. Inductively coupled plasma (ICP) based methods were used to determine the concentrations of 23 chemical elements in feed for ornamental and human fishes, ruminants, wild birds, rabbits, equines and ruminants. The limits of quantification obtained ranged from 0.02 mg kg-1 (Cd) to 76 mg kg-1 (Al). The reliability to the methods was confirmed by the analysis of certified reference material of oyster tissue (NIST 1566b) and tea (NCS DC 73351). The concentrations obtained ranged between 0.038 mg kg-1 (Sb) and 3.37% (Ca) for ornamental fishes, <LoQ (Ba) and 2.0% (Ca), <LoQ (Cd, Pb and Sb) and 2.0% (Ca) for rabbits, <LoQ (Cd, Pb, Sb and Se) and 2,53% (Ca) for wild birds, 0.034 mg kg-1 (Sb) and 2.10% (Na) for equines and, <LoQ (Se) and 14% (Ca) for ruminants, all of which are in accordance with Brazilian and American legislation. In the second work, a multivariate optimization of a sample preparation procedure in slurry was used to determine Ca, Cu, Fe, K and Mg in sugarcane juice samples by inductively coupled plasma optical emission spectrometry (ICP OES). The simultaneous designs (fractional factorial and Doehlert) were applied to optimize the variables: HNO3 concentration, H2O2 volume, sonication time, nebulizer gas flow and radiofrequency power for direct analysis of the sample as slurry. The procedure was validated by comparing digestion with addition and recovery tests. The proposed analytical method was applied for analysis of fourteen samples of sugarcane juice marketed in Aracaju, Sergipe, Brazil. The mean concentrations (in mg L-1) of 108 (Ca), 0.51 (Cu), 6.40 (Fe), 470 (K) and 114 (Mg) were obtained. The methodology presented offers a simple, fast, easy and efficient of sample preparation form simultaneous determination of Ca, Cu, Fe, K and Mg in sugarcane juice by ICP OES, after prepared as slurry. Finally, in the third work, the chemical speciation analysis of As, Sb and Se in dried fruit samples was performed using multi-syringe flow injection analysis hydride generation atomic fluorescence spectrometry (MSFIA-HG-AFS). For As and Sb determinations, the concentrations of NaBH4, KI and HCl were evaluated as factors. For Se determination, only concentrations of NaBH4 and HCl were evaluated. The two optimizations were performed through Doehlert designs, having the intensities of As, Sb and Se as response. Limits of quantification ranged from 0.34 (Sb total) to 15 ng g-1 (As total). The accuracy and precision of the analytical methods were evaluated through the analysis of certified reference material and addition and recovery tests. The analytical methods were applied to nine dried fruit samples, and the highest concentrations (in ng g-1) were 8.2 ± 0.6 for Sb(III), 14.0 ± 1.2 for Sb(V), 102.5 ± 7.4 for Se(IV) and 90.5 ± 9.8 for Se(VI). The As(III) and As(V) species obtained concentrations below the LoQ for all samples. In this work, analytical methods for the determination of total concentrations of essential and potentially toxic elements in food and feeds, and can be used for routine analysis to ensure food safety.  

10
  • MAURICIO BRANDAO DOS SANTOS
  • synthesis of ZSM-5 by interzeolite transformation from Y zeolite

  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • ARTUR JOSE SANTOS MASCARENHAS
  • HELOYSA MARTINS CARVALHO ANDRADE
  • MARITZA MONTOYA URBINA
  • SIBELE BERENICE CASTELLÃ PERGHER
  • Data: 26 avr. 2019


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  • Zeolites are materials strategically widely used in industrial processes of adsorption, separation or heterogeneous catalysis. Zeolites synthesis involves the use of silicon and aluminum sources, a mineralizing agent, and the use of structure directing agents (SDA), which may be inorganic and/or organic cations and organic molecule. The use of organic structure directing agents (OSDAs) despite having been a phenomenon of new structures, but is very costly for industrial purposes. In addition, the zeolites prepared in the presence of OSDAs require a step of burning the organic molecule, which requires a lot of energy and generates possible pollutant molecules. Thus, studies on the synthesis of zeolites without the use of organic directing have been encouraged as an alternative route, more promising from an economical and sustainable point of view. Seed use is another alternative, however, in many cases the seed is synthesized in the presence of organic molecules and the zeolitic phase of interest is not always obtained with the desired purity. In the last years, interzeolite transformation has returned to this scenario as an alternative to syntheses with OSDAs or with seeds due to shorter process time and cost. The two mechanistic routes proposed for the interzeolite transformation are sustained in thermodynamics by the Ostwald rule, according to which a given framework type evolves into a more dense structure, thermodynamically more stable structure, and kinetics, since they will preferably form, zeolites containing in their structure building units (CBUs, SBUs, RBUs) in common with the starting zeolite. However, there are some reports in the literature that counterpose these assertions. The studies carried out in this thesis indicate that the composition of the synthesis gel that favors the obtaining of the target topology can not be left aside. The approach based on both the Ostwald rule and the ring units building is the result of this composition and, therefore, the transformation can not be justified without correlating all the factors involved. Thus, even starting from a zeolite with SiO2/Al2O3 = 3 ratio,the addition of amorphous silica allowed to obtain units in 5-membered rings required to obtain the ZSM-5 and mordenite phases. However, the adjustment of the NaOH/SiO2 molar ratio was also preponderant because it enabled the control of the solubilization and repolymerization of the silicon and aluminum precursors that resulted in different zeolite pure phases such as ZSM-5, mordenite, analcima and cancrinite.

11
  • LEANE SANTOS NUNES
  • Analytical strategies using liquid-liquid microextraction with drop drop for determination of Manganese and Vanadium in water, beverage and food samples

  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MARIA DAS GRACAS ANDRADE KORN
  • RODOLFO DE MELO MAGALHAES SANTANA
  • VALFREDO AZEVEDO LEMOS
  • WALTER NEI LOPES DOS SANTOS
  • CLEBER GALVAO NOVAES
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • Data: 17 mai 2019


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  • The present work reports on the development of two analytical methods for the determination of manganese and vanadium using atomic absorption spectrometry with graphite furnace and the colorimetry of digital images. Within this context, two papers were prepared. The first consisted of the development of two liquid phase microextraction approaches (LPME), direct immersion droplet microextraction (DI-SDME) and continuous flow microextraction (CFME) using the reagent 1- (2-pyridilazo) -2-naphthol (PAN) as complexing agent and 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM] [PF6] as the extraction solvent. The extraction efficiencies were compared. Some variables of the preconcentration system were optimized using the univariate method. The developed system presented limit of detection and quantification of 0.17 and 0.51 μg L-1, respectively, enrichment factor of 17.67. The accuracy of the method expressed as relative standard deviation (% RSD, n = 10) was 6.15 using a 1.0 μg L-1 Mn (II) solution. The accuracy of the method was evaluated by determination of manganese in certified reference material of mussel tissue (SEM 2976). The concentrations  of  manganese found in  the  certified samples  ranged  from 4.16  to 4.85  μg g-1.The second work involved the development of a system for determination of vanadium (V) in water samples using SDME-DC (digital colorimetry and colorimetry with digital images). The analyte of interest was extracted into one drop of the solvent hexafluorophosphate of 1 The chemical analyzes were performed in an ImajeJ program that employs an RGB (red-green-blue) primary color space with values ranging from 0 to 255. The RGB data were extracted from cropped digital images of sizes The data obtained by the red channel were used to construct the analytical curve, since it presented the highest sensitivity. Under optimized conditions, the method presented enrichment factors of 50, the detection limit obtained was 0.45 μg L-1 and the limit of quantification was 1.43 μg L-1. The accuracy of the method was assessed by the analysis of a reference material certifi BCR-414, Plankton, from the Institute for Reference Materials and Measurements (IRMM, Geel, Belgium).

12
  • MANOEL ALVES MACHADO FILHO
  • Theoretical Study of Acid-Base Interactions Lewis and Reactive Processes in Compounds Organic

  • Leader : ROBERTO RIVELINO DE MELO MORENO
  • MEMBRES DE LA BANQUE :
  • ALVARO SANTOS ALVES
  • BOAZ GALDINO DE OLIVEIRA
  • FERNANDO DE BRITO MOTA
  • ROBERTO RIVELINO DE MELO MORENO
  • SILVIO DO DESTERRO CUNHA
  • TIAGO VINICIUS ALVES
  • Data: 22 mai 2019


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  • In this thesis, we study theoretically (i) the acid-base Lewis interactions formed between carboxylic acids and CO2 and (ii) reactive processes in organic compounds, such as Knovenaegel reactions and aldol condensations, of great interest for several application areas, especially green chemistry. Our calculations were performed at the level of density functional theory (DFT) and Møller-Plesset second-order perturbation theory (MP2). In case the (i) we present theoretical evidences that Lewis acid-base interactions should occur for carboxylic acids adsorbed on silver, by interacting with CO2. In addition, the study of the Raman and vibrational spectra calculated supposing a supercritical CO2 condition show that surfaceenhanced Raman spectroscopic (SERS) can be used to characterize such interactions, contributing to the formation of new compounds and surfaces with potential adsorption for CO2. In the case (ii) mechanisms of organic reactions involving Meldrum's acid and substituted aromatic aldehydes were studied and elucidated in light of computational procedures and experimental evidence. The understanding of which species of Meldrum acid is more reactive in aqueous medium through the proposition of mechanisms was the first and decisive step so that the reactions with aromatic aldehydes could be characterized and their proposals and experimental results for multicomponent systems could be understood at the level molecular, enabling other forms of reaction, prediction of new results and the follow-up of principles of green chemistry

13
  • GISSELI SOUZA VALASQUES
  • ANALYTICAL STRATEGIES USING EXTRACTION-INDUCED EXTRACTION INDUCED FOR QUANTIFICATION OF METAL AND METALOIDS IN OIL OIL
  • Leader : ANA MARIA PINTO DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ANA MARIA PINTO DOS SANTOS
  • MARIA ELISABETE MACHADO
  • SERGIO LUIS COSTA FERREIRA
  • CLEBER GALVAO NOVAES
  • MARCOS DE ALMEIDA BEZERRA
  • Data: 27 juin 2019


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  • Palm oil is an oily product of great interest to the food, cosmetics and biofuel industry. The presence of metals in this matrix is related to its oxidative stability, its nutritional value, the possibilities of contamination in the various stages of production, among other factors. The work presented in this paper deals with the development of analytical methods for the determination of metals and ametals in crude palm oil samples by atomic spectrometry techniques after emulsification assisted by ultrasonic energy followed by extraction induced by emulsion breaking (EIEB) as an alternative, simple, fast and efficient to the traditional processes of decomposition. In this context, the following works were carried out: (i) development of a method for the determination of Ca, Mg, Mn, Fe and Zn in oil crude palm oil by flame atomic absorption spectrometry (FAAS). The optimization of this method was done by constrained mixtures design and desirability function. The method have present limits of quantification between 0.018 and 0.19 mg L-1 and accuracy, expressed as repeatability (% RSD, N = 10) between 1.8 and 3.2% for the five metals studied. The accuracy of the method was achieved by applying addition/recovery tests of the analytes to the samples (obtaining recoveries between 87 and 113%) and by comparing the concentration values found by EIEB with the values found by dry decomposition, finding good agreement between these values. The application of the EIEB method in samples collected in the State of Bahia (Brazil) showed that the concentrations (mg L-1) of the samples were 3.93 to 13.9 (Ca), 0.37 to 2.26 (Mg), > LQ to 0.32 (Mn), 1.77 to 8.57 (Fe) and 0.38 to 2.54 (Zn); (ii) development of a method for the determination of As and Se in crude palm oil by atomic fluorescence spectrometry coupled to the hydrides generation (HG-AFS) and Hg by cold vapor generation (CV-AFS). Two-level fractional factorial design (25-1), Doehlert design and desirability function were used in the optimization process. The method presented limits of quantification of 0.72; 0.12 and 1.5 μg L-1 and accuracy expressed as repeatability (% RSD, N = 10, 5 μg L -1) of 1.7; 2.5 and 3.5% respectively for As, Hg and Se. The accuracy of the method was reached by addition / recovery tests (recoveries between 90 and 128%) and by comparison of the concentration values found by decomposition in Teflon® bombs, showing good agreement. The concentrations (μg L-1) of As, Hg and Se found in the samples were 1.28 to 1.58 (As) and 2.39 to 7.96 (Se). Concentrations of Hg were below LQ in the analyzed samples; (iii) development of a method for determination of Cd and Pb in crude palm oil by graphite furnace atomic absorption spectrometry (GFAAS). The method was optimized using Doehlert design and desirability function. The method have presented quantification limits of 0.16 and 0.12 μg L-1 and accuracy of 1.8 and 5.4% respectively for Cd and Pb. Accuracy was accessed by applying recovery/addition tests and values between 88.5 and 112% were obtained. Quantities of Cd and Pb respectively between 1.39 and 2.31 and 2.36 and 6.29 μg L-1 were found in the analyzed samples.

     

14
  • DANILO JUNQUEIRA LEÃO
  • ANALYTICAL STRATEGIES FOR DETERMINING MERCURY IN ENVIRONMENTAL SAMPLES
  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • WALTER NEI LOPES DOS SANTOS
  • VALFREDO AZEVEDO LEMOS
  • ADRIANO DE ARAÚJO GOMES
  • DÉBORA DE ANDRADE SANTANA
  • Data: 28 juin 2019


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  • The present work is about the development of analytical strategies for the determination of mercury in environmental samples using atomic absorption spectrometry with cold vapor generation (CV AAS). Mercury is a metal known to be toxic to the health of humans and ecosystems, standing out to have this toxicity even in low concentrations. Several studies reported in the literature show the need for the development of new, more sensitive methodologies for determination and analysis of mercury speciation, since this analyte is characterized by trace concentrations and is one of the main current concerns when it comes to contamination environmental. Within this context, two papers were developed. The first one consisted in the development of a method of determination of mercury in sediment samples by optimization of a simple procedure of extraction of the analyte of the samples for later determination by CV AAS. Such optimization was performed using multivariate optimization techniques, evaluating the influence of the factors in the analyte extraction step. The factors evaluated were: hydrochloric acid concentration, thiourea concentration, sonication temperature and sonication time. After optimization, the accuracy of the method was confirmed by the analysis of two certified reference materials, Channel Sediment (BCR-320R) and San Joaquin Soil (NIST 2709a). The detection and quantification limits were 1.04 and 3.46 ng g-1, respectively, and the precision, in terms of RSD%, was 4.31%. The method was applied for the determination of mercury in sediment samples collected in the São Paulo Estuary, located in the state of Bahia, Brazil, whose concentrations ranged from 13.8 to 38.5 ng g-1. The second work involved the development of an automated system for the determination of mercury in natural water samples employing multiserial flow injection analysis (MSFIA) and cold vapor generation atomic absorption spectroscopy (CV AAS). The experimental conditions were investigated and optimized using multivariate optimization methodology, such as complete factorial design (2k) and Doehlert Matrix. The optimized variables were: hydrochloric acid concentration, sodium borohydride concentration, sample flow and entrainment gas flow. The proposed method allowed the direct determination of mercury in natural water samples, that is, without preconcentration stage, with limits of detection and quantification of 43.0 and 145.0 ng L-1, respectively. The accuracy of the method was confirmed by analysis of certified water reference material, Trace elements in waste water, (CASS-4). The matrix effect was evaluated by addition and recovery tests in saline water samples, as the method was optimized using aqueous standards, obtaining recoveries above 82%. The method was applied in a sample of sea water and lake of the city of Salvador, Bahia, Brazil, whose concentrations ranged from 0.36 to 1.14 μg L-1.

     

15
  • OSÉAS SILVA SANTOS
  • N2O assisted  methanol conversion over acid and base catalysts

  • Leader : HELOYSA MARTINS CARVALHO ANDRADE
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • ARTUR JOSE SANTOS MASCARENHAS
  • CARINE TONDO ALVES
  • HELOYSA MARTINS CARVALHO ANDRADE
  • RAILDO ALVES FIUZA JUNIOR
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • VALERIA CRISTINA FERNANDES
  • Data: 28 juin 2019


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  • Nitrous oxide (N2O), a pollutant that contributes to the greenhouse effect and depletion of the ozone layer, is one of the main protagonists, along with methanol, in this study. In this sense, this work was developed to evaluate nitrous oxide as an oxidizing agent in basic and acidic reactions using methanol to obtain formaldehyde and dimethyl ether, respectively. In the basic catalysis catalysts of cobalt oxides derived from lamellar double hydroxides were used as catalysts for the conversion of methanol to formaldehyde in the presence of nitrous oxide. The catalysts were characterized by various techniques. The test results showed 100% methanol conversion and 91% selectivity to formaldehyde were simultaneously obtained with 100% N2O conversion at 440 ºC over a Co,Mg,Al-mixed oxide catalyst. Higher hydrogen yields and lower CO and CO2 yields were obtained than when air was used as oxidizing agent, under the same conditions. At another time, as a complementary study, these same oxides catalysts were prepared by inserting cerium by the co-precipitation method. In this study, Cobalt and Cerium doped oxides were characterized and tested in the selective catalytic oxidation of methanol assisted by N2O. It was obtained 100% methanol conversion, 100% N2O conversion and 91% formaldehyde yield were obtained on the CoMgAl catalyst. The catalysts containing cerium were more active in the conversion of N2O at lower temperatures (350 - 400 ºC), but presented lower formaldehyde yields, due to the increase of oxidation products (CO and CO2) formation. In general, the basic reaction with oxides derived from HDLs suggests that the reaction occurs on a combination of redox and basic catalytic sites. On the other hand, acidic catalysts were used for H-ZSM-5 and Co-ZMS-5 acid catalysts for the dehydration reaction of methanol to N2O-assisted dimethyl ether (DME). During this study, high conversion of methanol (78 %) and yield and selectivity to DME of 70 and 90 %, respectively, were obtained at 300 °C. During the stability test the Co-ZSM-5 catalyst was shown to be thermally stable and catalytically in the N2O/CH3OH reaction (1:3) with low generation of polyoxymethylene dimethyl ethers (POMEs) (<10%). In conclusion N2O acts in the removal of the carbon deposits avoiding the intensive coking of the acid catalyst. On the other hand, the formation of surface oxygen species due to N2O decomposition generated a higher number of moderate (or density) sites, contributing to the selective formation of DME. N2O can be used as an oxidizing agent in industrial processes of economic importance, such as assisting in the reaction of selective oxidation of methanol to formaldehyde or in the dehydration reaction of methanol to dimethyl ether.

16
  • ELISÂNGELA COSTA SANTOS
  • CHEMICAL / GEOCHEMICAL CHARACTERIZATION OF SEDIMENTS OF THE LOW STRAIN OF THE SAN FRANCISCO RIVER TO ASSESS ENVIRONMENTAL IMPACTS

  • Leader : VANIA PALMEIRA CAMPOS
  • MEMBRES DE LA BANQUE :
  • VANIA PALMEIRA CAMPOS
  • MARIA ELISABETE MACHADO
  • ANTONIO FERNANDO DE SOUZA QUEIROZ
  • JOSE ROBERTO BISPO DE SOUZA
  • YVONILDE DANTAS PINTO MEDEIROS
  • RAILDO MOTA DE JESUS
  • Data: 5 juil. 2019


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  • The low strain of the São Francisco river covers an area that divides between the States of Alagoas and Sergipe, in the stretch after the Xingó Dam, to its mouth, in the city of Sergipe. The objective of this work was to characterize, through chemical and geochemical parameters, the sediments of the low strain of the São Francisco River, in order to evaluate possible environmental impacts. Samples of surface sediments were collected during three seasons, two in dry season (February 2014 and December 2015) and one in the rainy season (July 2016), in the two margins of four transects, totaling 8 sampling points. Core samples of sediments were collected in 7 localities (Pão de Açúcar-AL, Niterói-SE, Traipu-AL, Gararu-SE, Xinaré-AL, Pindoba-SE, Ilha das Flores-SE) in July 2016 at the depths of 2 to 44 cm, to verify the influence of the dams on sedimentation behavior. The Environmental Protection Agency's analytical procedure, EPA 3051A, was applied to the sediments and trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP OES). The origin and sources of organic matter (OM) were evaluated using elemental ratios by elemental analysis coupled to mass spectrometry. The results obtained after partial decomposition of the sediment samples in microwave oven and determination by ICP OES were evaluated through guideline values established by sediment quality guides. It was possible to infer that the samples collected in the low strain of the São Francisco river presented clayey minerals of the kaolinite and ilite type. Concentrations of As in PA-AL (2014) and IF-SE (2015, 2016) were above the criteria of the values for TEL (Threshold Effect Level) and PEL (Probable Effect Level). The concentrations obtained for Cd in PA-AL, GA-SE, IF-SE (2014 to 2016), NI-SE, XI-AL, PI-SE (2014 and 2016), TA-AL (2016) and PE-AL (2015 and 2016) were above the minimum value established by the Canadian and US legislation, TEL and LEL (Lowest Effect Level). In PA-AL (2014) and NI-SE (2016) the values exceeded that established by the Canadian legislation (PEL). In IF-SE (2016) the values are above the limits established by the US legislation, SEL (Severe effect level). The concentration values found for Cr in sediments of SE-SE (2016) presented levels above the lower thresholds established by the American legislation (LEL). The calculated potential ecological risk index reflects great concern in the NI-SE and IF-SE locations, since it was between moderate to high in 2016. By the calculated ecological risk factor for the different locations in the different periods, it can been that the elements As, Cr, Cu, Ni and Pb offer greater ecological risk. In relation to phosphorus, it was observed that a decrease in the flow rate for the NI-SE, TA-AL, GA-SE, XI-AL, PE-AL and IF-SE discharges resulted in an increase in P concentration in the sediment. The results on the origin and source of OM related to the sediments of the Low strain of the São Francisco river revealed different constitutions composed of  bacteria, marine algae and C3 plants. The stable isotopes δ13C and δ15N evidenced the presence of sewage, fertilizers, cyanobacteria and OM typical of the estuary. In this way, it is inferred that the work carried out warns about the need for a monitoring in the region of the low strain of the São Francisco river, since the reduction of the flow is more felt by the localities closest to the mouth, due to the decrease of fresh water in relation to the entrance of the sea water, occurring accumulations of OM, fertilizers and trace elements. The work also contributed to the generation of a database on the composition and quality of sediments of the low strain of the São Francisco River

17
  • EDUARDO BATISTA GUIMARÃES NUNES DOS SANTOS
  • Exploring solid phase of Al(OH)3 produced in situ by homogeneous precipitation assisted by microwaves radiation for fast extraction of chemical species 

  • Leader : MAURO KORN
  • MEMBRES DE LA BANQUE :
  • MAURO KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MADSON DE GODOI PEREIRA
  • DÉBORA DE ANDRADE SANTANA
  • Data: 5 juil. 2019


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  • The aluminum hydroxide precipitation in homogeneous solution assisted by microwave radiation for the extraction of organic compounds, coprecipitation of metallic ions and inorganic anion species removal were studied. Unlike what occurs in conventional precipitations, where the precipitant is added, facilitating the production of colloids, precipitation in homogeneous solution produces more pure crystals that are rapidly agglomerate, speeding up the filtration of solids. When irradiating with microwaves, the urea solutions in the presence of aluminum ions leads to the formation of overheating zones and the fast decomposition of urea causes a local pH increasing and the production of Al(OH)3 in situ, which aids to separate other chemical species from the solution. In order to investigate the ability to organic compounds separation with the solid phase produced in situ, some experiments were carried out to extract neutral and electrically charged dyes. The results showed that the Al(OH)3 had a strong affinity for neutral organic compounds, with extraction rates higher than 80% for Congo red dye, betacarotene, humic acid and curcumin. The extraction of phenolic compounds by the proposed separation process was studied and the removal capacities for quercetin, quercitrin, morin, kaempferol, rutin, caffeic acid, ferulic acid, dopamine, L-dopa and chlorogenic acid from aqueous solutions were estimated. As, only quercetin was quantitatively removed with the precipitate (> 99%), an alternative process was developed for the separation and preconcentration of quercetin in aqueous extracts of onion sample without using organic solvents. Studies about the coprecipitation of metallic cations and anions separations during the Al3+ in situ precipitation process were carried out. The coprecipitation of metals by homogeneous precipitation of microwave assisted Al(OH)3 was evaluated in aqueous solutions and brines. Higher recovery rates (> 70%) were obtained for Cr, Fe, Pb and Cu, allowing the determination of Cr and Fe contents in brine samples by atomic spectrometric techniques without the interference of sodium. The proposed irradiation coprecipitation process was applied to evaluate the feasibility of trace metal determination in commercial samples of special salts for culinary uses (black salt, flakes of flower of salt and Himalayan pink salt). Higher separation rates for Cr and Fe were estimated for flower of salt and pink salt samples due to the high sulfur content characteristic of the black salts. Finally, the transfer of large inorganic anions (phosphate and dichromate) from aqueous solutions to the Al(OH)3 produced from homogeneous microwave-assisted precipitation was evaluated and an efficient  phosphate extraction to Al(OH)3 solid phase in solutions without chloride and nitrate ions was obtained (> 99%). Phosphate ions determination in fertilized vegetal soil samples and cola soft drink were evaluated and the results indicated strong matrix effects due to competition between organic compounds and inorganic anion. The effect of dichromate ion presence in aqueous and brine solutions were also evaluated.

18
  • JEFERSON DO ROSARIO ALMEIDA
  • The integration of Nanomaterials in the Cell Wall of Filamentous Fungi for the production of biohybrid and biomimetic materials.

  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • PAULO ROBERTO RIBEIRO DE JESUS
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MARCOS MALTA DOS SANTOS
  • REGINA MARIA GERIS DOS SANTOS
  • ANTONIO FERREIRA DA SILVA
  • HAMILTON BRANDÃO VARELA DE ALBUQUERQUE
  • ARNAUD VICTOR DOS SANTOS
  • MADSON DE GODOI PEREIRA
  • Data: 26 juil. 2019


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  • The present work aims to integrate nanomaterials to the cell wall of filament fungi, aiming the production of luminescent biohybrid materials and semiconductor biomorphic materials. In order to obtain luminescent biohybrid materials, fungi of the species Aspergillus niger, Phialomyces macrosporus and Trichoderma spp were grown in a medium containing luminescent lanthanide metal-organic framework (Tb-MOFs and Eu-MOFs). The biohybrid was characterized by scanning electron microscopy (SEM), fluorescence optical microscopy and luminescence spectroscopy that revealed integration of the MOFs in the cell wall of the three fungal species. Fluorescence light microscopy images also showed that MOF particles are also transported to the intracellular region of the fungi and are stored in the vacuoles. The internalization of the MOFs in the intracellular region of the fungi opens a vast field for the application of these materials in the treatment of infectious fungi. To produce biomorphic materials, the biohybrids of the fungus Phialomyces macrosporus and titanium oxide (anatase) were submitted to a hydrothermal treatment (100-140 ° C) in alkaline medium (10M NaOH solution). The XRD measurements associated with SEM images, transmission electron microscopy (TEM) and X-ray dispersive energy (EDS) showed the production of microtubes made from sodium titanate nanotubes. The variation of NaOH concentration (6.5 to 8.0 M) allowed the formation of microtubes composed of sodium titanate nanoribbons. A mechanism has been proposed for the formation of nanoribbons on the biomorphic structure that takes into account the slow degradation of the cell wall components and adhesive substances that keeps the TiO2 particles bound to the fungal hyphae.

19
  • THIAGO FONTES DA HORA SILVA
  • SÍNTESE MECANOQUÍMICA DE ARILIDENOS, CUMARINAS E 4-CLOROACETANILIDA

  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • SILVIO DO DESTERRO CUNHA
  • JORGE MAURICIO DAVID
  • VALERIA BELLI RIATTO
  • LOURENCO LUIS BOTELHO DE SANTANA
  • AMENSON TRINDADE GOMES
  • Data: 26 juil. 2019


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  • The Mechanochemistry is based on the use of mechanical energy to promote breakage and bond formation due to high pressure and temperature increase by friction, usually in the absence of solvent, being used in carbon-carbon, carbon-heteroatom, oxidation, reduction, condensation, coupling and organometallic synthesis. Using dedicated laboratory equipment, its application on sophisticated synthetic routes became more reliable due to the control of the energy transferred to the reagents and, thus, greater reproducibility, thus arousing the interest of organic-synthetic scientists. In this work a bibliographic review was made on the use of mechanochemistry in Organic Synthesis, and a study of some reactions between Meldrum's acid and aldehydes with donor substituents and electron withdrawals. Some reactions lead to the formation of arylidenes while others lead to the formation of coumarin acids, due to the presence of a hydroxyl in the 2 position of benzaldehyde, both of which are reactions of Knoevenagel where the compound with active hydrogen (carbanion) is Meldrum’s acid. In the development of the methodology to obtain coumarinic acids an experimental design of central compound and multi-response analysis was performed to optimize the reaction conditions. In addition, we developed the first mechanochemical synthesis of 4-chloroacetanilide as an effective alternative to the experimental class of Green Organic Chemistry.

20
  • KLEBSON SOUZA SANTOS
  • Photodegradation of cyanide species in wastewater from cassava flour production with simultaneous fuels production assisted by photocatalysts TiO2.Nix.NiO

  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • RAILDO ALVES FIUZA JUNIOR
  • LUCAS BOMFIM BOLZON
  • LUCIANA ALMEIDA DA SILVA
  • ALEXILDA OLIVEIRA DE SOUZA
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • Data: 19 août 2019


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  • Damage to water bodies is considered one of the biggest environmental problems today. In view of this, several advanced technologies are being developed for the treatment of contaminating effluents and industrial waters. In this context, the present work focused on the development of a photocatalytic system capable of treating the wastewater from cassava flour production, an effluent rich in cyanide species and other organic compounds, aiming to reduce the pollutant load and, at the same time to recover part of the biomass energy remaining from the tubercle processing. This study involved the synthesis of nickel-doped TiO2 by the sol-gel method, using different concentrations of Ni, followed by thermal treatment in oxidizing and oxidizing/reducing atmosphere. The materials prepared were characterized by X-ray diffractometry, scanning electron microscopy and diffuse reflectance spectroscopy, later used as photocatalysts in the photocatalytic treatment of manipueira water in a bench reactor and argon atmosphere, irradiated with light λ > 370 nm. The results obtained after photocatalytic treatment for 5 hours demonstrate a decrease in the concentration of cyanide species from 8.93 mg L-1 of total cyanide to 5.18 mg L-1 when treated with pure TiO2 and 0.19 mg L-1 when treated with TiO2.Ni/NiO (sample obtained with 25% (m / m) Ni followed by heat treatment in an oxidizing atmosphere). The monitoring of the gaseous effluents produced during the degradation of the cyanide species and organic matter identified the presence of molecular hydrogen and ethene. The ethene production rate was in the range of 0.0667 to 1.029 μmol g-1 h-1 for nickel doped materials at different concentrations and the production of this gas was not detected when pure TiO2 was used. On the other hand, hydrogen production range was from 2.0761 μmol g-1 h -1 using TiO2 doped with 25% (m) of Ni with hydrogen to 0.0985 μmol g-1 h-1 for pure titanium dioxide.

21
  • MILENA DE SANTANA SANTOS
  • PEROVSKITAS BASED ON NICKEL, COBALT AND LANTHANUM APPLIED ON THE PARTIAL OXIDATION OF METHANE AND COMBUSTION BY CHEMICAL CYCLE

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • SORAIA TEIXEIRA BRANDAO
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • RAILDO ALVES FIUZA JUNIOR
  • JAIME SOARES BOAVENTURA FILHO
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • Data: 30 août 2019


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  • Perovskite with composition LaNi1-xCoxO3 (x = 0.0, 0.2, 0.5, 1.0) were studied in the partial oxidation of methane (POX), in the total oxidation (combustion) by chemical looping and in the catalytic combustion of methane. These samples were synthesized by the citrate method and characterized by different methods, such as XRD, specific area by the BET method, TPR-H2, TPSR-CH4, XPS, TEM, TGA, Raman spectroscopy were evaluated by TPSR-CH4/O2 and by long term tests under different conditions. In POX, the main results indicate that the mechanism of transformation of oxides LaNi1-xCoxO(x = 0.2 and 0.5) under atmosphere of CH4 and O2 is dependent on the oxide composition (x = 0.2 and 0.5) and pretreatment conditions (in this case, x = 0.2). The sample (x = 0.5), independent of previous H2 treatment, evidence of the formation of intermediate phases La2BO4 (B = Ni and CO) was noted. However, with the sample (x = 0.2) the mechanism involves the formation of the spinel phases (La2BO4) only in the condition that there was no pretreatment with H2. In all experiments, the phase changes of the oxides (LaNi1-xCoxO3 and Ni1-xCox/La2O3) under atmosphere of CH4 and O2 resulted in the
    Ni1-xCox/La2O3 system. The performance of the catalytic tests in different conditions with the sample (x = 0.2) suggested that the pretreatment with H2 favors the synthesis gas at a H2/CO ratio closer to the theoretical value (2) when compared to the pre-treatment treatment with the reaction mixture (CH4 + O2). During the tests no evidence of catalyst deactivation was observed, but the reaction of OPM contributed to the formation of graphite carbon on these materials. The LaNi0.5Co0.5O3 oxide showed better performance during the chemical cycle combustion tests, this sample led to the complete reduction in a shorter time as well as showed less susceptibility to deactivation due to the formation of coke in the catalytic combustion of methane, all samples were active, it was verified that the addition of cobalt contributed to obtain a more stable catalyst.

22
  • MILENA DE SANTANA SANTOS
  • PEROVSKITAS BASED ON NICKEL, COBALT AND LANTHANUM APPLIED ON THE PARTIAL OXIDATION OF METHANE AND COMBUSTION BY CHEMICAL CYCLE

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • JAIME SOARES BOAVENTURA FILHO
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • RAILDO ALVES FIUZA JUNIOR
  • SORAIA TEIXEIRA BRANDAO
  • Data: 30 août 2019


  • Afficher le Résumé
  • Perovskite with composition LaNi1-xCoxO3 (x = 0.0, 0.2, 0.5, 1.0) were studied in the partial oxidation of methane (POX), in the total oxidation (combustion) by chemical looping and in the catalytic combustion of methane. These samples were synthesized by the citrate method and characterized by different methods, such as XRD, specific area by the BET method, TPR-H2, TPSR-CH4, XPS, TEM, TGA, Raman spectroscopy were evaluated by TPSR-CH4/O2 and by long term tests under different conditions. In POX, the main results indicate that the mechanism of transformation of oxides LaNi1-xCoxO(x = 0.2 and 0.5) under atmosphere of CH4 and O2 is dependent on the oxide composition (x = 0.2 and 0.5) and pretreatment conditions (in this case, x = 0.2). The sample (x = 0.5), independent of previous H2 treatment, evidence of the formation of intermediate phases La2BO4 (B = Ni and CO) was noted. However, with the sample (x = 0.2) the mechanism involves the formation of the spinel phases (La2BO4) only in the condition that there was no pretreatment with H2. In all experiments, the phase changes of the oxides (LaNi1-xCoxO3 and Ni1-xCox/La2O3) under atmosphere of CH4 and O2 resulted in the
    Ni1-xCox/La2O3 system. The performance of the catalytic tests in different conditions with the sample (x = 0.2) suggested that the pretreatment with H2 favors the synthesis gas at a H2/CO ratio closer to the theoretical value (2) when compared to the pre-treatment treatment with the reaction mixture (CH4 + O2). During the tests no evidence of catalyst deactivation was observed, but the reaction of OPM contributed to the formation of graphite carbon on these materials. The LaNi0.5Co0.5O3 oxide showed better performance during the chemical cycle combustion tests, this sample led to the complete reduction in a shorter time as well as showed less susceptibility to deactivation due to the formation of coke in the catalytic combustion of methane, all samples were active, it was verified that the addition of cobalt contributed to obtain a more stable catalyst.

23
  • RAVIR RODRIGUES FARIAS
  • Use of the copper catalyzed azide-alkine cicloading methodology in the synthesis of symmetric bis-triazoles. Investigation of it’s physical, biological characteristics and as a binder

  • Leader : MAURICIO MORAES VICTOR
  • MEMBRES DE LA BANQUE :
  • ELIANA MIDORI SUSSUCHI
  • JORGE MAURICIO DAVID
  • MAURICIO MORAES VICTOR
  • ROSSIMIRIAM PEREIRA DE FREITAS
  • SILVIO DO DESTERRO CUNHA
  • Data: 4 oct. 2019


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  • Copper-catalyzed azide-alkyne cycloaddition reactio, known as CuAAC reaction, has been investigated in the synthesis of symmetric bis-triazoles from terminal diazides and alkynes. The conditions for obtaining the desired products have been optimized: Copper catalyst sources and the stoichiometric relationship between terminal diazids/alkynes were investigated in the CuAAC methodology. This research aimed to symmetric bis-triazoles and the investigation of their physical, biological and ligand properties. The manipulation allowed the formation of the 4-substituted alkyl-phenyl bis-triazoles in moderate to excelente yields. However, the optimized methodology applied to oxygenated alkynes did not work or led to low yield products. The best result for antifungal activity was obtained by bis-triazole 170 which presented the same fluconazole®  MIC (32 μg.mL-1) against Candida Krusei ATCC 6258, na emerging and potentially multiresistant fungal pathogen. Due to its versatility of biological activity, five hydroxyl bis-triazoles showed no inhibition of leishmanicidal activity between 15.0 and 20.0 %, at concentrations of 20 and 40.0 μg.mL-1. Among these compounds, derivative 172 presented the best value of IC50 (63,34 μg.mL-1, 182,86 μM). Regarding cytotoxicity, all compounds were inactive. It was also observed through infrared spectra, the effect of presence and absence of H binding on the triazole ring characteristic bands. In addition, in order to verify the stability of diazids, the termal study was performed using the DSC technique, diazide 154 presented na exothermic event at a temperature of approximately 130.0 °C.  1,3-Bis(4-butyl-1H-1,2,3-triazol-1-yl) propan-2-ol 158 was successfully applied as a binder for the determination of Cu(II) ions by electrode modified in cultivated with bordeaux treatment. The detection limito f the method (LOD) and the limit of quantification (LOQ) were 1,67x10-9 mol.L-1 and 5,05x10-9 mol.L-1, respectively, and the amount of ions of copper found in a real sample of was 8,05 μg.kg-1, a value within the standards stipulated by ANVISA.

24
  • WILSON ELIAS ROZO NUÑEZ
  • MECHANOCHEMICAL STUDY OF THE REACTIVITY OF 3,4-DIBROMOFURAN-2(5H)-ONA IN THE SYNTHESIS OF HOMO-ALDOIS AND HETEROPOLICYCLES
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • ANDRE ALEXANDRE VIEIRA
  • CAIO COSTA OLIVEIRA
  • KLEBER THIAGO OLIVEIRA
  • MAURICIO MORAES VICTOR
  • SILVIO DO DESTERRO CUNHA
  • Data: 11 oct. 2019


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  • In this thesis, a study of furanone reactivity against different nucleophiles such as phthalimide, cyanide salts, ammonium thiocyanate, sodium iodide and sodium azide was performed. In this way it was possible to obtain high purity derivatives without the need for chromatographic purification and high yield.
    In addition, we also explored the mechanochemical synthesis of homoaldols, furobenzopyranones, and coumarin and 1,2,3-triazole hybrids.
    The mechanochemistry allowed to perform transformations in the absence of solvent and shorter reaction times.
    For the first time, the mechanochemical synthesis of furanone-derived homoaldols is described, with yields ranging from 22 to 67%.
    A mechanochemical method was developed for obtaining the nucleus of 2Hfuro[3,2-b]benzopyran-2-one, creating a library of 11 molecules, of which two are coumarin hybrids. The yields ranged from 44 to 91%. Due to the fluorescence of these molecules, their photophysical properties were evaluated and showed promising results.
    The classic Pechmann method for the synthesis of coumarins was optimized. By this procedure at least 10 molecules can be obtained.

25
  • LEILA MARIA MENDES SANTOS
  • Photocatalytic remediation of organophosphate pesticide using ZnO and TiO2 based photocatalysts and a natural clay

  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • LUCIANA ALMEIDA DA SILVA
  • JOICY SANTAMALVINA DOS SANTOS
  • PEDRO AFONSO DE PAULA PEREIRA
  • JEANCARLO PEREIRA DOS ANJOS
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • Data: 29 nov. 2019


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  • In recent years pesticide use has become intense to meet the food demand of the world's growing population. The increase in the generation of more pesticide residues requires an effective and sustainable approach capable to degradate these environmental pollutants. A process based on the photocatalysis is presented in this work as a sustainable, efficient and low cost alternative for remediation of this type of pollutant. In this context, the photocatalytic activity of toxic metal-free materials with potential use of solar power was evaluated in the degradation of fention, an organophosphate pesticide. The photocatalysts evaluated were pure and nitrogen-doped TiO2 and ZnO (TiO2-N and ZnO-N), as well as in the form of composites with a hematite-rich natural clay (TiO2/Tauá and ZnO/Tauá, where tauá is a Brazilian indigenous word that means red clay). The photocatalysts were prepared by sol-gel and Pechini methods of synthesis. X-ray diffraction analysis has confirmed the presence of TiO2 and ZnO phases in the doped materials and composites, which were also characterized by SEM, EDX and DRS. The study of surface chemistry by the adsorption method was able to identify the ideal pH condition for better photocatalytic activity. The photocatalysts were irradiated with visible and ultraviolet light aided with the oxidant H2O2. The monitoring of fention concentration during irradiation was performed using a spectrophotometric method after dichloromethane extraction. ZnO/Tauá and TiO2/Tauá composites were the most active photocatalysts when compared to individual components and doped oxides, reaching 90.3% and 87.0% photodegradation, respectively. The optimization of reaction parameters for the most active photocatalyst (ZnO/Tauá) resulted in fention photodegradation within 30 minutes when the initial pesticide concentration was 30 mg L-1 and the H2O2 concentration was 100 mg L-1.

26
  • FRANCIELE OLIVEIRA SANTANA
  • Gaseous contaminants/pollutants in the atmosphere of Brazilian urban centers.

  • Leader : VANIA PALMEIRA CAMPOS
  • MEMBRES DE LA BANQUE :
  • VANIA PALMEIRA CAMPOS
  • PEDRO AFONSO DE PAULA PEREIRA
  • MARCOS DE ALMEIDA BEZERRA
  • MARTA VALERIA ALMEIDA S. DE ANDRADE
  • PÉROLA DE CASTRO VASCONCELLOS
  • Data: 6 déc. 2019


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  • Gases and particulate matter as atmospheric contaminants/pollutants affect the health of the city populations, causing serious damage to the fauna/flora, building materials and monuments. Vehicle emissions have been considered the predominant source of air quality degradation in large cities. In 2018, ambient air pollution caused 4.2 million deaths worldwide. This work comparatively evaluated the concentrations of 16 atmospheric pollutants / gaseous contaminants from 5 Brazilian urban centers (São Paulo, Salvador, Rio de Janeiro, Belo Horizonte e Londrina), with intense vehicular flow and different characteristics, such as location type (coastal or noncoastal), demographic density and weather conditions, use of passive sampling. Six simultaneous passive sampling campaigns were performed using the AnalyseAr kit for consecutive periods of 7 and 14 days. BTEX compounds were quantified by gas chromatography (GC) with flame ionization detection (FID); HCOH and CH3COH by high performance liquid chromatography (HPLC) with UV-Vis detection; NOx, NO2, NH3 and H2S by molecular spectrophotometry and SO2, O3, HCl, HNO3, HCOOH and CH3COOH by ion chromatography (IC). O3 was the gaseous pollutant with the highest concentration in the city of São Paulo, 58 µg m-3 , ranging from 5.3 to 139 µg m-3 in all the centers. In terms of average levels of atmospheric concentration, most compounds presented higher concentrations in the dry period. São Paulo and Belo Horizonte showed higher concentration levels, corroborating the intensity of the vehicle fleet, allied to meteorological parameters; specifically NOx levels, which exceeded the European Union recommendation (30 µg m-3 ). Formaldehyde and acetaldehyde exceeded international recommendations in all urban centers and benzene concentrations showed values > 1.7 μg m-3 , a level associated with the probability of leukemia, according to the World Health Organization (WHO). The ratios Toluene / Benzene (T/B), Xylenes / Benzene (X/B), m, p-Xylenes / Ethylbenzene (m,p-X/E) and Formaldehyde / Acetaldehyde (FA/AA) indicated that vehicle emissions are the main sources of these Volatile Organic Compounds (VOCs) in the atmosphere of Brazilian urban centers. The cancer risk probability for adults that were exposure to those atmospheres was above the 1.0 x 10-6 , exceed the limit established by the USEPA for both benzene, and for formaldehyde. The emission of diesel vehicles was considered the predominant source for the increase of nitrogen oxide concentrations. NH3 concentrations indicated a significant contribution of anthropogenic emissions from biofuel use, industrial sectors or fertilizer. Urban centers with influence of marine aerosol presented lower concentrations of HNO3, indicating occurrence of reaction of this acid with NaCl in sea spray particles, producing particulate matter and HCl(g). Direct discharges of sewage into water bodies, when present at the sites, contributed to an increase in H2S, toluene and NH3 levels. Ratios between the concentrations of formic and acetic acid and strong positive correlations between nitrogen pollutants, conventional pollutants and VOCs between them indicated significant influence of vehicular emissions in the atmosphere of these urban centers. Organic and inorganic acids presented a similar contribution to atmospheric acidity, with acetic acid most abundant in most of the centers studied. Multivariate analysis showed that VOCs and organic acids are more influenced by temperature and solar radiation parameters. The strongest direct relationship of NOx was with wind direction, shown competition between in loco emission and photochemical aging of these compounds brought from other locations. In general, vehicular emissions are the predominant sources of gaseous pollutants in the urban atmosphere and photochemical reactions combined with meteorological parameters contribute to the seasonal variation of the levels of these pollutants/contaminants.

27
  • WILSON BITENCOURT BARRETO JÚNIOR
  • INVESTIGATION OF PHOTOCATALYTIC ACTIVITY OF TiO2 BASED MATERIALS AND STUDY OF 
    ATRAZIN PHOTODECOMPOSITION.
  • Leader : ADRIANE VIANA DO ROSARIO
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • ARTUR JOSE SANTOS MASCARENHAS
  • RAILDO ALVES FIUZA JUNIOR
  • GILBERTO ABATE
  • LUCIANA BAGDEVE DE OLIVEIRA DOS SANTOS
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 6 déc. 2019


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  • Titanium dioxide (TiO2) is one of the most used semiconductors due to its excellent characteristics and because it can be applied in many areas, specially in photocatalysis. TiO2 has a band gap of 3.2 eV, meaning an absorption in near UV–UVA region, limiting its use. In addition, the high recombination rate of the photogenerated charge carriers, damage its performance. Therefore, it is necessary to increase its absorption spectrum and to produce modifications on the oxide that avoid the charge carriers recombination process. One alternative is the addition of others transition metals to the oxide synthesis, either by doping or by the mixed phases formation. In this work, Zn2+ and W6+ ions were added to the TiO2 synthesis by the Pechini method. Two photocatalysts groups, Zn-TiO2 and W-TiO2, were prepared with different dopant concentrations and at different temperatures (500oC and 700oC). Initially, the catalysts were tested using a model compound (methylene blue – MB), in order to investigate the photoactivity of these materials, and after use them in the study of the decomposition of the atrazine (ATZ) herbicide. AM and ATZ photodegradation processes were monitored by UV-Vis spectroscopy and high efficiency liquid chromatography (HPLC) techniques. Semiconductors were characterized by x-ray diffraction (XRD), diffuse reflectance and BET-surface area. These studies allowed us to evaluate the photoactivity of the synthesized materials and to relate the catalytic behavior with their structural and optical characteristics. The addition of Zn2+ and W6+ leads to different effects on TiO2 structural properties. For the heat treatment at 700oC, the increase of Zn2+ addition induced the partial conversion of the anatase phase to rutile and for the higher Zn2+ concentration levels, a ZnTiO3 phase segregation occurred. In the case of the W-TiO2 system synthesized at the same temperature, the increasing on the W6+ concentration reduced the anatase phase particle size and the conversion of the anatase to rutile. At high W6+ concentrations, a WO3 segregate phase also to arise. Both systems showed improvement of photocatalytic activity in the decomposition of MB. However, the best results were presented by samples containing W6+. Exceptionally, samples with high W6+ amount showed catalytic activity in the absence of UV and visible light. Atrazine photodegradation was performed with the samples that demonstrated the greatest potential for application. The best results were obtained with the catalyst sample containing 2.0 mol% of W6+, whereby the atrazine concentration was reduced in 37% in the first 60 min and was almost completely consumed after 420 min. During the ATZ decomposition process, the degradation products desethylatrazine (DEA) and desethyldesisopropyl-atrazine (DE-DIA) were detected.

28
  • FREDSON SANTOS GUIMARÃES
  • Cracking and hydrocracking of soy oil on acidic and basic catalysts for obtaining biofuels.
  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • HELOYSA MARTINS CARVALHO ANDRADE
  • LUCIANA ALMEIDA DA SILVA
  • ROGER THOMAS FRANCOIS FRETY
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 10 déc. 2019


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  • Most of all the energy consumed in the world comes from oil, coal and natural gas. These sources are limited and are expected to be depleted. Thus, the search for alternative sources of energy is of paramount importance. The use of fuels derived from biomass has been identified as an alternative, reducing the dependence on fossil fuels for both economic and environmental reasons. The global concern with climate change also extends to air transport, which has few alternatives to conventional fuels due to its dependence on liquid fuels with high energy density, which allow long flight autonomies without increasing the weight and the volume to be transported. There is a wide variety of raw materials with different plant and animal sources, such as soybeans, babassu, canola, oil palm, pork fat, among others, and conversion processes that can potentially be used for the production of aviation biofuels. Among the raw materials used, vegetable oils stand out. The cracking of vegetable oils is a promising route in obtaining biofuels. The process takes place at temperatures above 350 ° C, in the presence or absence of catalyst. In this reaction, the breakdown of the triglyceride molecules leads to the formation of a mixture of hydrocarbons and oxygenated compounds, in addition to carbon monoxide and dioxide and water. Catalysts with acidic and basic characteristics have been investigated in the cracking of vegetable oils. Among these, we can highlight zeolites and oxides derived from layered double hydroxides. Zeolites have acidity, size and pore distribution that make them very active and selective in the catalytic cracking of vegetable oils. Already oxides derived from double layered hydroxides, with basic properties, are indicated for deoxygenation via decarbonylation, where oxygen is eliminated as CO. In order to improve the properties of biofuel, hydrocracking was a good alternative to reduce the amount of oxygenates in the product obtained. This reaction took place in the presence of acid catalysts (zeolites, HZSM-5 containing 2, 5 and 10% nickel and HMCM-22 containing 2%) and basic (oxides derived from lamellar double hydroxides). These catalysts proved to be effective for cracking (except MgAl-LDH) and hydrocracking to produce a biofuel in the kerosene range, however with considerable oxygenate content.

29
  • VIVIANA OLIVEIRA MATEUS
  • CATALISADORES DE FERRO E MOLIBDÊNIO SUPORTADOS EM CARVÃO ATIVADO PARA REAÇÃO DE HIDROGENÓLISE DE DERIVADOS DE BIOMASSA

  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • ADRIANE VIANA DO ROSARIO
  • RAILDO ALVES FIUZA JUNIOR
  • LUIZ ANTONIO MAGALHAES PONTES
  • RODRIGO DE PAULA
  • Data: 11 déc. 2019


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  • The insertion of matter from inexhaustible sources is required by commerce and therefore industry. Biomass has emerged as a promising alternative in the diversification of the industrial platforms, the transformation of biomass directed to processes that guarantee competitive prices in relation to those coming from fossil fuels is desirable. Acid catalysts are required in the process in order to favor the hydrolysis of cellulose in the hydrogenolysis reactions of cellulose to aid in the formation of sugars and the dehydration of glycerol to acrolein in the hydrogenolysis reactions of glycerol, for example. In contrast, the metallic characteristics of the catalysts tend to favor hydrogenation leading to the formation of 1,2 and 1,3 propanediol in the hydrogenolysis reactions of glycerol and sorbitol in the hydrogenolysis reactions of the cellulose. Commonly, hydrogenolysis is employed in the sense of providing breakage of the C-C and C-O bonds that make up the structure of the biomass such as cellulose and glycerol. The effects of the acidic and metallic characteristics of the catalysts, therefore, tend to favor the process of breaking the rigid bonds present in the cellulose, as well as in the direction of the reactions of hydrogenolysis of the glycerol, the formation of chemical inputs much required by industry as propene under conditions reactions. The catalysts containing molybdenum and iron supported on charcoal seem to be a promising route, as it has acidic and textural characteristics that probably favor the conversion of cellulose, as well as that of glycerol. The use of the activated carbon in this case, to favor the dispersion of the catalysts and, therefore, the availability of the active centers to react. In this context, the study of iron and molybdenum catalysts supported on activated carbon for the reaction of hydrogenolysis of biomass derivatives (hydrogenolysis of cellulose and hydrogenolysis of glycerol) was studied and the many appreciable characteristics for its use in these reactions were explained. Hydrogenolysis of glycerol at 500 ºC proved to be more promising for obtaining propylene in catalysts containing molybdenum, while at 300 ºC it proved to be more selective for obtaining methane, ethane, ethylene or CO. Propylene production yielded 15% of the total 6 hours of reaction at 500 ºC for CMF. The post-test characterization of catalysts submitted to 300 ºC and 500ºC indicated that the phases discussed in the TPR in the characterization were obtained and, therefore, the Fe2MoO4, Fe2Mo3O8, FeMoO4, MoO2, Fe phases in the samples containing molybdenum and iron, as well as the Mo8O23 phase were observed. The TG post catalytic test indicated the presence of a large amount of oxides for all cases. Hydrogenolysis of cellulose carried out at 205ºC has shown promise in obtaining HMF and furfural molecules at 50 bar. The catalyst CF indicated favoring the formation of glycerol, CM to HMF and furfural and CMF to the formation of HMF and acetol mainly. The results indicated that acidity governs the reaction, as well as the active phase. These results indicate that hydrogenation was favored in the CF catalyst, while CM and CMF probably occurred in hydrogenolysis. The 50 bar pressure may have favored the in situ reduction of the catalyst and possibly the mechanisms of cellulose hydrogenolysis were favored for CM and CMF.

2018
Thèses
1
  • THAIS LUZ DE SOUZA
  • MULTILEMENTARY QUANTIFICATION AND BIOACCESSIBILITY ASSESSMENT OF Al, Cu, Fe and Zn IN PROTEIN SUPPLEMENTS AND NUTRITIVE FLOURS

     
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • GABRIEL LUIZ DOS SANTOS
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • Data: 20 avr. 2018


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  • In this work a method for the determination of macro and microelements in samples of protein-based supplements manufactured by Brazilian and North American companies and commercialized in Salvador, Bahia, Brazil, was developed. The procedure was based on the decomposition of samples in microwave oven with cavity and determination of analytes by inductively coupled plasma optical emission spectrometry (ICP OES). The multiple response of the inorganic constituents and the residual carbon content were used to evaluate the efficiency of the decomposition of the samples. The results showed that no variable was significant in the Pareto graph. The selected conditions were: concentration 2,0 mol L-1 de HNO3, 1,0 mL de H2O2 and heating temperature of 210°C. The accuracy of the method was verified with NIST CRM certified reference materials 1549 (non fat milk) and addition and recovery test showing recovery percentages between 90 to 111% and 92 to 104%, respectively. The proposed method presented good accuracy (RSD <10%) and low detection limits (between 0.01 and 2.92 μg g -1). The concentration ranges, in μg g-1, in the supplemented samples analyzed were: Al (< 1,85 – 59,3), Ca (367 - 5594), Cu (0,56 – 9,16), Fe (1,56 – 78,4), K (1527 - 7107), Mg (<1,85 - 847), Mn (<0,05- 9,93), Na (457– 3640), P (1785 - 5895), Se (<0,78– 3,58) e Zn (<1,36 – 20,5). In a second step, the total content of Al, Ca, Cu, Fe, K, Mn, Na, P and Zn in the nutrient meal was determined by a validated method. The accuracy of the method was verified with NIST CRM 3234 and NIST 1518b (CRM) soybean meal, with recovery percentages ranging from 86 to 103% and 78 to 102%, respectively. Samples were obtained from commercial establishments in Salvador, Bahia. The concentration ranges, in μg g-1, determined by ICP OES were: Al (4,8 - 232,0), Ca (508 - 8989), Cu (<0,01 -59,6), Fe (8,4 – 167,0), K (2984 - 15508), Mn (<0,01- 53,8), Na (<0,39 - 2995), P (476 - 9759) e Zn (<0,07- 30,3). The bioaccessibility was applied through the UBM method in vitro in the studied samples and the results indicated that the most bioaccessible element in the gastric phase was Zn in both supplements and in the flour. The bioaccessible percentages at this stage are in the range of (82 to 96%) and (60 to 100%) for supplement and flour samples, respectively. The bioacessible fractions of the gastrointestinal phase were lower in relation to the gastric phase. The main component analysis (PCA) and hierarchical grouping analysis (HCA) were applied to the total content results obtained from nutritional supplements and meal. A similarity trend was observed between the supplement samples and in the flours there was a dispersion among the studied varieties. The present work presents unpublished information of the bioaccessible fractions of the elements in the supplement samples and flours.

2
  • MILENA DA SILVA CAVALCANTE BROTAS
  • DETERMINATION OF ESSENTIAL FATTY ACIDS ÔMEGA-3 AND ÔMEGA-6 IN FISH OIL CAPSULES CONSUMED AS A FOOD SUPPLEMENT
  • Leader : PEDRO AFONSO DE PAULA PEREIRA
  • MEMBRES DE LA BANQUE :
  • GISELE OLIMPIO DA ROCHA
  • MARTA VALERIA ALMEIDA S. DE ANDRADE
  • PEDRO AFONSO DE PAULA PEREIRA
  • Data: 31 juil. 2018


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  • The literature shows that essential fatty acids of the ω-3 and ω-6 series stand out in several physiological functions, such as prevention of cardiovascular diseases and atherosclerosis, improvement of the endothelial function and blood pressure reduction, besides to present anti-inflammatory properties. However, these acids cannot be synthesized by the human body and therefore it’s important to ensure their presence in the human diet, through the intake of foods which are rich in their presence, such as some kinds of fish and seafood. An alternative that has emerged regards the intake of fish oil capsules, which are sold in pharmacies or in natural products stores. In this way, it becomes important to monitoring the information in the product labeling, comparing them with what is actually offered to the consumer, based in obtained results. In the present work, a method was optimized for the determination of longchain poly-unsaturated fatty acids of the ω-3 and ω-6 series, based on derivatization and analysis by gas chromatography coupled to mass spectrometry (CG-MS). The method has shown good linearity in the dynamic range from 5 to 100 mg. L-1 for eicosahexaenoic acid - EPA and docosahexaenoic acid - DHA and 0,5 to 10 mg. L-1 for oleic, linoleic and linolenic acids, with R2 values greater than 0,99 for all the analytes. The detection limits (LOD) ranged between 0,16 mg. L-1 and 0,18 mg. L-1 , the quantification limits (LOQ) between 0,46 and 0,63 mg. L-1 , while the intraday and interday precisions varied, respectively, between 0,77% - 6,54% and 1,57% - 4,03%, with relative recoveries higher than 76%. The method was then applied in the analysis of ten different brands of encapsulated fish oil marketed in Salvador, and the results are reported at the end.

3
  • VANESSA SALES DE CARVALHO MELO
  • DETERMINATION AND FRACTIONATION OF MERCURY IN SEDIMENTS COLLECTED IN SÃO PAULO RIVER, BAHIA

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • KARINA SANTOS GARCIA
  • MARIA ELISABETE MACHADO
  • SERGIO LUIS COSTA FERREIRA
  • Data: 6 août 2018


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  • Mercury (Hg) is one of the metals most toxic to the environment and can be found in many compartments. In sediments, it can be retained for a long time and be released into the environment after many years by natural or anthropogenic actions. The mercury also has properties of bioaccumulation and biomagnification, being absorbed directly or indirectly by the biota in the environmental compartment. Therefore, it is noted the importance of understanding the association and distribution of mercury, which is usually accomplished by applying chemical extraction procedures. In this sense, this study aimed to determine and evaluate the concentration of mercury in the estuarine sediments of the São Paulo river, located in the Candeias - Bahia region. So, the sediment sampling was performed in 3 points in 3 campaigns (March, June and September 2014). In these samples, the total mercury concentration (HgT) was determined using the mercury analyzer Direct Mercury Analyzer (DMA-80). The labile mercury was extracted using a 0.5 mol L-1 HCl solution in a shaking system for 2 hours and the concentration was determined to employ atomic fluorescence spectrometry. The concentration of HgT ranged from 38,0 to 107,0 ng g-1 and the extraction of mercury with 0.5 mol L-1 HCl as extraction solution was able to extract between 76.5 and 112.6 ng g-1 of Hg, allowing to conclude that the mercury is in the labile form. However, the value is within the limits indicated by the CONAMA / 2004 resolution. A test was performed using dithiothreitol (DTT) as a small-scale mercury extractor by a sonication step for 50 min, and the reading was performed on the Direct Mercury Analyzer (DMA-80). The DTT was considered a good extractor of mercury in sediments. The concentrations of Fe, Mn, Si, and Al were also determined in the sediments using X-ray fluorescence spectrometry. High levels were found for these elements suggesting high adsorption capacity of mercury. The capacity of mercury retention by sediments of this river was evaluated by adsorption studies. The kinetic study indicated that the adsorption suffers effects of diffusional limitation and the intraparticle diffusion occurs in two stages, being controlled by the stage of intraparticle diffusion in the micropores of the sediment.

4
  • OSCAR CAETANO DA SILVA NETO
  • BERGENIN INSULATION AND PREPARATION OF BIOATIVE DERIVATIVES
  • Leader : JORGE MAURICIO DAVID
  • MEMBRES DE LA BANQUE :
  • ELIANE DE OLIVEIRA SILVA
  • JORGE MAURICIO DAVID
  • CLAYTON QUEIROZ ALVES
  • Data: 9 août 2018


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  • The present work describes a methodology for the isolation of bergenin from Peltophorum dubium Spreng. Taub. roots and the preparation of derivatives bioactives from the pure compound. Peltophorum dubium (Fabaceae) is a native forest species with wide geographical dispersion. Popularly it is known by several names, such as ''amendoim bravo'', ''faveiro'', “pau vermelho”, “angico” and “canela de veado”. The roots, leaves, flowers and fruits are employed for different treatments in folk medicine. Bergenin is present in various plant genera and it shows different pharmacological activities such as hepatoprotective, anti arthritis, antibacterial and anti-inflammatory. Thus, an extraction simple method for bergenin was developed from the methanolic extract of the roots of P. dubium based on the precipitation of glycoside and purification by usual chromatographic methods. It showed a good yield in relation to the extract and to the roots used. From the pure natural compound five derivatives have prepared by the Williamson synthesis route using alkyl halides with variable carbon chain. All derivatives were obtained with good yields (75 – 92%), and the PMB8 derivative (5,7-Dioctylbergenin) presented the highest yield. PMB1 derivatives (5.7-Dimethylbergenin), PMB8 (5,7-Dioctylbergenin), PMB10 (5,7- Didecilbergenin) and PMB14 (5,7-Ditetracilbergenin) showed moderate toxicity when they were tested against Artemia salina nauplii. PMB6 (5,7-Dihexylbergenin) presented as toxic (CL50 = 70.55 µg mL-1 ) and, pure Bergenin show no toxicity (CL50 = 2682.90 µg mL-1 ). In the DPPH radical quenching test, it was observed that the bergenin had effective activity (% SRL above 70%) and the derivatives presented lower antioxidant activities (% SRL below 13%). In the test of AchE (Acetylcholinesterase) inhibition, Bergenin showed activity higher than the positive standard (IC50 = 141.19 µg mL-1 ), and the derivatives presented percentage of inhibition lower than the standard. The structural elucidation of the isolated and prepared compounds was based on spectral data analysis with the comparison with literature data.

5
  • Fabrícia Nunes da Silva
  • SYNTHESIS AND CHARACTERIZATION OF NEW LUMINESCENT LIQUID CRYSTALS DERIVED FROM HETEROCYCLO 2,1,3-BENZOXADIAZOL

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ANDRE ALEXANDRE VIEIRA
  • FERNANDO MOLIN
  • MAURICIO MORAES VICTOR
  • Data: 10 août 2018


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  • The synthesis and characterization of new organic functional materials (ten unpublished molecules with high π conjugation) based on the 2,1,3-benzoxadiazole heterocycle will be described throughout this work. These materials were designed to exhibit luminescent and mesomorphic properties. For this the center containing the heterocycle is attached to different aromatic units by means of carbon-carbon triple bonds, through the Sonogashira cross coupling. Its thermal properties were investigated by DSC, TGA, MOLP and XRD and their optical properties through their absorption spectra and photoluminescence in solution and film are described. The structure of this work was divided into two series. The first one aims at a direct comparison between analogs containing the 2,1,3-benzothiadiazole nucleus already described in the literature and the benzoxadiazoles obtained, in order to evaluate the effects caused by the replacement of the sulfur by oxygen, the comparison of these properties occurred in front of the wide application of the benzoxadiazoles in optical-electronics. All molecules in this series showed mesomorphism due to temperature, nematic and smectic, typical of calamithic thermotropic liquid crystals, the compounds were preferably nematic phase over a wide temperature range, and showed strong green fluorescence. In the second moment, it was proposed to investigate no longer the effect caused by the substitution of the nucleus, but to evaluate the effects caused by the variation of the nature and position of the substituents in the aromatic portions. In this series, not all compounds showed mesomorphism or stability of the same. The mesophases presented were of the nematic type and esmetic A and C. The comparison between compounds of different series with the same alkyl chain differing only by the presence of the nitro group in meta in one of the cases, surprised by the impact caused in the mesomorphic properties. Due to the different substituents the photophysical properties showed large variations of yellow-green. In the solid phase, the photophysical studies presented great displacements of the maximum wavelengths in comparison to the studies realized in solution. The most important of the film studies were the quantum yield values and the excellent quantum yield response with heating of these materials.

6
  • JAINARA SANTOS DO NASCIMENTO
  • BIOTRANSFORMATION OF PHENOLIC SUBSTANCES BY FUNGI FILAMENTS AND EVALUATION OF THE BIOLOGICAL ACTIVITIES OF GOT DERIVATIVES
  • Leader : ELIANE DE OLIVEIRA SILVA
  • MEMBRES DE LA BANQUE :
  • DANIELA APARECIDA CHAGAS DE PAULA
  • ELIANE DE OLIVEIRA SILVA
  • VALERIA BELLI RIATTO
  • Data: 10 août 2018


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  • Current new diseases emergence and the resistance development by some pathogens have driven the chemical studies to reach new and biologically actives compounds. Among the different classes of organic compounds, the phenolic ones have attracted interest from chemistries, since these natural products display bioactivities such as antioxidant, antimicrobial and cytotoxic. The phenolic compounds, such as the coumarins, have a highlighted place due to their wide applications on agrochemical, food, cosmetic and pharmaceutics industries. Although phenolic compounds are biosynthesized as secondary metabolites by plants, bacteria, and fungi, the achievement of these compounds can be expensive, difficult and generates low yields. Therefore, the biotransformation of natural phenolic compounds is an alternative way and a powerful approach to obtain phenolic compounds in high scale. The aim of this study was investigating about the potential of three strains of filamentous fungi to the biotransformation of two phenolic a  ds (building blocks of the shikimate biosynthetic pathway) and of nine synthetic coumarins. The achievement of phenolic bioactive compounds with unknown chemical structures was valued. The preliminary biotransformations were developed by different incubation times. The chemical profiles of the extracts were evaluated by chromatographic procedures aiming to choose the most promising processes to perform tests in preparative scale. The biotransformation of phenolic acids by Aspergillus brasiliensis ATCC 16404 and Trametes versicolor ATCC 200801 showed that the fungi biotransformed some substrates. The high polarity of the derivatives and the complexity of the extracts prevented the isolation and chemical identification of the derivatives. Analysis of the chemical profiles of the biotransformation of coumarins by A. brasiliensis and Cunninghamella elegans ATCC 10028b revealed that the enzymes of both fungi transformed only two of the nine studied coumarins. We hipothesized that the presence of one hydroxyl grou  on the aromatic ring and a bulky group in the lactone ring are essential structural characteristics for the biotransformation occurrence. The biotransformation of coumarins resulted in the isolation of two derivatives, and their chemical structures were determined by spectroscopic techniques. Additionally, it was verified that both fungi produced the same metabolites from biotransformation of the coumarins. The antimicrobial activities of the derivatives and substrates were evaluated against Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538. The minimum inhibitory concentration (MIC) values were in all cases superior of 400 μg/mL. Chloramphenicol was used as positive control and displayed MIC values of 12.5 μg/mL against S. aureus, and 25.0 μg/mL against E. coli and P. aeruginosa.

7
  • JOÉLEM CARVALHO DE MELO
  • DIRECT SAMPLE ANALYSIS OF RESTRICTED POWDER FOR QUANTIFICATION OF INORGANIC CONSTITUTIONS EMPLOYING FS-F AAS AND ICP OES

  • Leader : DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MARIA DAS GRACAS ANDRADE KORN
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • ERIK GALVÃO PARANHOS DA SILVA
  • ELANE SANTOS DA BOA MORTE
  • Data: 14 sept. 2018


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  • The objective of this work was to propose analytical methods for determination of inorganic constituents in samples of refreshment powdered using spectroanalytic techniques. Firstly, a procedure was developed aiming refreshment direct analysis for determination of Cd, Co, Cu, Fe, Mg, Mn, Ni, Pb and Zn by fast sequential flame atomic absorption spectrometry (FS- F AAS). A full 23 factorial design was applied and the variables were chosen: acid concentration (0.1-0.5 mol L -1), acid type (HCl and HNO3) and sonication time (0-10 min). The optimization provided the best condition, using 0.5 mol L-1 HCl, without sonication, considering a mass of 0.18 g of refreshment powdered completed to a final volume of 15 mL. The matrix effect was investigated by comparing the sensitivities of analytical curves prepared in diluted acid medium and by addition of analyte. The analyte addition and recovery test was applied to evaluate the accuracy, obtaining values of recovery percentage ranging from 83.9% to 109.7%, considered adequate for quantitative analysis. The accuracy of the analyzes was evaluated from the relative standard deviation (% RSD), being less than or equal to 5.0%, for all analytes. The procedure was applied to 26 samples of refreshment powdered commercialized in Salvador (Brazil) and Buenos Aires (Argentina). The concentration range of the analytes in the samples were (in μg g -1): Fe (18.2 - 376), Mg (34.9 - 3139), Mn (3.74 - 4.88), Co (7. 9 - 10.3), Zn (<1.4 - 1.68). The concentrations of Cd, Cu, Ni and Pb were below the limit of quantification (LoQ) of the proposed analytical method. A second analytical method of direct introduction of the sample for determination of inorganic constituents by inductively coupled plasma optical emission spectrometry (ICP OES) was proposed. A Doehlert design was used to optimize the operating conditions of the spectrometer, as radiofrequency power (PRF: 1200 - 1500 W) and nebulization gas flow (VGN: 0.6 - 1.0 L min-1). After analyzing the data, it was obtained the condition of PFR of 1350 W and VGN of 0.9 L min-1. The matrix effect was also evaluated by comparing the sensitivity of analytical curves prepared in acid medium and by addition of analyte. The accuracy of the analytical method was evaluated by analyzing the certified reference material of tomato leaves (CRM-Agro C1003a), after dilution with refreshment powdered sample prepared, and the values obtained were agreement with values certified for the level of 95% confidence. The analyte addition and recovery test was applied, obtaining recovery values between 85.6% for calcium and 120.3% for phosphorus, being considered adequate for quantitative analysis. The procedure was applied to 29 refreshment powdered samples commercialized in Salvador (Brazil), Buenos Aires (Argentina) and Santiago (Chile). The concentrations obtained for analytes were in the bands (μg g-1) between Ca (33.812700), Fe (8.1-440), K (122-7367), Mg (6.1-4753), Mn (0.28 - 9.1), Na (<600 - 39806), P (557 - 7325), Ti (2.80-2643) and Zn (0.36-1.15). The concentrations for Cd, Co, Cu, Ni and Pb were below the LoQ. Nevertheless, the methodologies for direct analysis of refreshment powdered, after simple treatment of the samples, were fast, presenting the reduction of reagent consumption and less generation of residues, offering a lower risk to the operator, besides ensuring reliability of the analytical results.
     
     
8
  • LEANDRO GONÇALVES BENZI
  • DETERMINATION OF TOTAL SELENIUM CONTENTS IN DIETARY SUPPLEMENTS USING QUANTUM DOTS AS FLUORESCENT PROBES

  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • RICARDO QUEIROZ AUCÉLIO
  • RODOLFO DE MELO MAGALHAES SANTANA
  • Data: 23 nov. 2018


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  • Selenium dietary food supplements are consumed looking for its nutritional benefits, however, the ingestion of high levels of selenium, can cause a severe intoxication known as selenosis, so, the development of quality control methods is desirable. Quantum dots has been widely used as fluorescent probes for the detection of several analytes, organic and inorganics in different types of samples. The present work aim to a new analytical method development for selenium determination using TGA capped CdTe quantum dots in dietary supplements samples. Validation was accomplished by evaluation of linear range, limit of detection, limit of quantification, accuracy and precision. Sample treatment and accuracy studies were performed according to FDA-US official method. Different Se concentration in aqueous media led a progressive enhancement of QD fluorescence. In addition, was observed a huge improve in analytical sensitivity (ΔF>90%) in ammoniacal buffer (0.01 mol L-1) at pH= 8.4, under an addition order equal to: (i) sample, (ii) buffer, and (iii) QD. The LOD and LOQ were equal to 60.5 and 173 μg L-1, respectively. The linear range had an upper limit of 450 μg L-1, with good linearity (R2 = 0.9956, n = 6) and precision (RSD ≤ 3.5% for 250 and 450 μg L-1, n = 8).  Three different supplements samples were analyzed and mass values equal to 41.9±3.9 μg, 128.4±5.7 μg and 48.8 ± 0.9 μg were found. For two samples, no significant difference was observed at 95% confidence level. Thus, the proposed method was a good alternative for determination of total selenium content in supplements with good analytical throughput, accuracy and precision.

9
  • CRISTIAN LINS DA CRUZ ALMEIDA
  • STUDY OF BIOCATALITIC REACTIONS INVOLVING FUNCTIONAL MICROORGANISMS WITH METAL OXIDES: AN ALTERNATIVE FOR GLYCEROL VALORIZATION

     
  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • DÉBORA DE ANDRADE SANTANA
  • GISELE ANDRE BAPTISTA CANUTO
  • LOURDES CARDOSO DE SOUZA NETA
  • MARCOS MALTA DOS SANTOS
  • REGINA MARIA GERIS DOS SANTOS
  • Data: 7 déc. 2018


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  • The objective of this master's dissertation was to integrate particles of TiO2 (titanium oxide anatase) and WO3 (tungsten trioxid) in Aspergillus niger and Phialomyces macrosporus fungi’s cell walls and to study a production of organic acids by these biohybrid from the conversion of glycerol. Initially, the A. niger/TiO2, A. niger/WO3, P. macrosporus/TiO2 and P. macrosporus/WO3 bio-hybrids were grown in 50 mL of a solution containing BD and particles of TiO2 (0.40 g) and WO3 (0.58g) during four days. Then, it was added a solution containing 20 mL of glycerol and the system was kept in fermentation for more ten days. The resulting fermented broth containing glycerol, the BD medium and the bioconversion products passed by a process of extraction using a 2: 3 (v / v) extractive mixture of dichloromethane/ethyl acetate with 1% (v / v) of formic acid. Using a scanning electron microscopy (SEM), the bio-hybrids had their morphology studied to verify the characteristics of the material after the fermentation period. A chromatography method utilyzing the high efficiency liquid chromatography (HPLC) coupled to diode (DAD) and refractive index (IR) chromatography was optimized for the analysis of fermented broth samples in which the chromatography conditions employed were the use of a Lichrospher® C18 (4.6 x 250 mm, 5 μm) column from Agilent (Germany), mobile phase composition of 2% acetonitrile, 49% 0,1% phosphoric acid solution and 49% water, isocratic method, 6 mL.min-1, temperature column of 35°C, analysis time of 15 minutes and injection volume was 20 μL. The selected wave ‘s length was 210 nm. The optimized variables served as the basis for the development of an analytical method LC-ESI-IT, whose chromatographic conditions were the use of a Kromasil C18 (4.6 mm x 250 mm, 5 μm) chromatographic column as composition of the mobile phase the solvent A = H2O and phomic acid (0,1% v / v), solvent B = acetonitrile. The elution gradient started isocratic for 13 min with 5% B, after 14-24 min the concentration of 5-100% B was increased and in 25 min the concentration returned to 5% acetonitrile until the end of the 35 min analysis. The flow rate of the mobile phase used was 0.6 mL.min-1 and the injection volume was 20 μL. From a semi-quantitative analysis, the production of citric acid in appreciable amounts and lactic acid in small amounts (traces) by A. niger/TiO2 and P. macrosporus/TiO2 hybrids compared to native cultivated fungi in glycerol medium. The A. niger/TiO2 bio-hybrid produced a 3-fold higher amount of citric acid when grown in glycerol medium as compared to the native fungus.
     
     
10
  • CAROLINA COSTA FREITAS
  • STUDY OF CATALYSTS BASED ON Mo AND NiMo SUPPORTED IN ALMCM-41 IN THE FLASH PYROLYSIS REACTION OF DODECANOIC ACID

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • SORAIA TEIXEIRA BRANDAO
  • AROLDO FÉLIX DE AZEVEDO JÚNIOR
  • CAMILA RIBEIRO DE OLIVEIRA FÉLIX
  • Data: 14 déc. 2018


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  • The production of biofuels from triglycerides has become an interesting alternative, since it allows to reduce the use of fossil fuels. Through flash pyrolysis, the cracking process acts in the absence of oxygen and high temperatures, triglycerides that produce products in the gasoline, diesel and kerosene range, as well as important by-products for the petrochemical industry. Using catalysts to improve the quality and quantity of products generated. In this work, we studied the flash pyrolysis of dodecanoic acid and the differences generated when to apply the Al-MCM-41, MoAl-MCM-41 and NiMo-Al-MCM-41 catalysts with theoretical Si / Al ratio equal to 60. The analysis of the products showed that the presence of the catalysts modifies the quantity and distribution of the same. In the presence of the Al-MCM-41 and NiMoAl-MCM-41 catalysts which present moderate acid sites in higher concentration, it was verified the total conversion of the fatty acid mainly to terminal olefins in the range of gasoline and aromatics (Benzene, Toluene and p -Xylene). In the pyrolysis reaction with the Mo-Al-MCM-41 catalyst there were no significant amounts of products, probably due to the presence of only weak acidic sites on the surface of this material.

11
  • TATIANE DE JESUS SANTOS
  • INFLUENCE OF PARTIAL REPLACEMENT OF CEMENT BY GRANULAR MARBLE WASTE IN CEMENT PASTOR PROPERTIES AND REDUCTION OF CO2 EMISSIONS

  • Leader : HELOYSA MARTINS CARVALHO ANDRADE
  • MEMBRES DE LA BANQUE :
  • HELOYSA MARTINS CARVALHO ANDRADE
  • JARDEL PEREIRA GONCALVES
  • RAILDO ALVES FIUZA JUNIOR
  • Data: 17 déc. 2018


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  • The use of marble waste as a partial replacement of the cement in cement matrices appears as an alternative for the reduction of the CO2 emission resulting from the cement manufacture, in addition to providing the reuse of a waste generated on a large scale. In this work the physical, chemical and mechanical effects of the partial replacement of CP V-ARI (SR) cement by granular white marble waste were studied. The performance of the waste with no previous treatment was compared with the performance of the milled waste. The study also evaluated the potential of the marble waste as an alternative for the reduction of the CO2 emissions from the cement production process.  The slurries were prepared with 0, 10, 20 and 30% of waste as cement replacement and water/cement ratio of 0.4. The results showed that the addition of the marble waste did not significantly affect the cement hydration process, and the residue did not presented chemical activity. It was observed an improvement in the properties of the cement slurries, especially for the slurries with 10% of replacement, which is related to the better packaging of the matrix and greater refinement of the pores. Finally, a reduction of 0.311 million tons of CO2 per year was calculated for the replacement of 10% of CP V-ARI cement by marble waste. This indicates that the use of the residue in cement matrix is a promising alternative. 

12
  • THIARA BORGES DA MATTA
  • ELEMENTARY CHARACTERIZATION OF CULTIVARS OF COLORED COTTON (GOSSYPIUM HIRSUTUM L.) PRODUCED IN THE NORTHEAST REGION

  • Leader : AMALIA GEIZA GAMA PESSOA
  • MEMBRES DE LA BANQUE :
  • AMALIA GEIZA GAMA PESSOA
  • LUANA NOVAES SANTOS
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • Data: 18 déc. 2018


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  • This work aims to characterize samples of several colored cotton cultivars commonly found in the Northeast Region of Brazil. With the results obtained, it is expected that the detailed information on the presence of macro and microelements will support the development of the economic activities associated with the cultivation of these species, such as the establishment of certificates of origin of colored cotton, providing greater added value to this type of product. In this study the factorial analysis 2³ was applied followed by a Doehlert plan, to optimize the procedure of microwave-assisted microwave cavity decomposition using dilute acids. The optimized conditions of digestion were established in 3.5 mol.L-1 of HNO3 and 3 mL of H2O2. Inductively coupled plasma optical emission spectrometry (ICP OES) was determined by determination of Al, Ca, Cu, Cr, Fe, K, Mg, P and Zn. The accuracy and precision of the methodologies were evaluated through the analysis of the certified reference materials 1515 apple leaves, 1547a peach leaves and the concordances between the experimental values and the certified values varied between 85 and 114% and the RDS values were lower to 16% evidencing the efficiency of the methodology proposed for preparation of the cotton samples was adequate. The relationship between the elemental profile and the cotton cultivar was investigated through the use of multivariate techniques for the recognition of PCA (Principal Component Analysis) and HCA (Hierarchical Component Analysis) standards. Through this tool it was possible to identify a tendency of separation between samples of cultivars Topázio and Rubi A.

13
  • BRENO CERQUEIRA DA SILVA
  • KINETIC, THERMODYNAMIC AND EXPERIMENTAL STUDY OF DRY REFORM OF METHANE IN OXYGEN PRESENCE EMPLOYING PEROVSKITE-TYPE CATALYTIC PRECURSORS.
  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • JAIME SOARES BOAVENTURA FILHO
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • SORAIA TEIXEIRA BRANDAO
  • Data: 19 déc. 2018


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  • Perovskite-type catalytic precursors with general formulation La1-xxNi1-yAlyO3 (x= 0.05; 0.25; 1; 0, e y = 0; 0.5; 0.8), being “M” cerium or strontium, were synthesized by the amorphous citrate method. After the synthesis the materials were precalcined at 100 ° C for 1h and 300 ° C for 2h, followed by subsequent calcination at 800 ° C for 5h. The non-calcined samples were characterized by thermogravimetric and thermodifferential analysis. After the heat treatment, the perovskites were characterized by X-ray diffraction (XRD), X-ray diffraction under reducing atmosphere (DRX-H2), Programmed Temperature Reduction (TPR), TPSR-OD and thermoprogrammed cracking of methane (TPC-CH4). A thermodynamic study on oxy-dry was carried out using the Gibbs free energy minimization method, evaluating the reactions allowed for the system under study and the subsequent proposal of a reaction mechanism, consistent with the experimental data and previous studies available in the literature. Transient temperature tests were performed to evaluate the effect of temperature, variation of space velocity, carbon dioxide fraction and the effect of the catalyst over the reaction mechanism. It was found that the replacement of lanthanum by cerium provided an increase in the overall activity of the materials, favoring the breakdown of the C-H bond, and providing a mechanism of coke oxidation by the network oxygen. Strontium, in turn, gave rise to less active materials, due to the formation of SrCO3, whose presence is unavoidable by the proposed synthetic method. The replacement of nickel by aluminum significantly reduced the ignition temperature for combustion reactions, but required higher energies for the initiation of syngas production reactions. The increase in temperature thermodynamically favors the production of synthesis gas by means of dry methane reforming, but also allows for greater carbon deposition through the decomposition of methane. It was also observed that with the reduction of the spatial velocity the conversion of the reactants was favored. The order of activity observed in the transient studies was CeNiO3 > LaNiO3 > SrNiO3.

14
  • DANILLO SANTOS DE OLIVEIRA MATA
  • Synthesis and Characterization of Ni/La2O3 e Ni/CexOy/La2O3 Catalysts Applied in the Dry Reform of Methane in Oxygen Presence.

  • Leader : LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • Data: 20 déc. 2018


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  • Currently there is a growing demand for energy resources and a concern to reduce environmental impacts due to the use of fossil fuels. Hydrogen appears as an energetic and environmentally positive source, being its main source the natural gas, composed mainly by CH4. Natural gas is available in large quantities and on the rise, presenting as a viable source in obtaining synthesis gas (H2 + CO) from catalyzed reactions such as methane reforming. This work aims at the synthesis of Ni, La and Ce based catalysts, synthesized by the sol-gel method via the citrate route (NLP and NLCP) and by wet impregnation (NLS8, NLS5 and NLCS) for the dry reforming of CH4 in the presence of O2 to give H2. These materials were characterized by x-ray diffraction (XRD) of calcined, reduced and post-catalytic test samples; Determination of specific surface area and isotherms; Reduction with H2 at the programmed temperature (TPR); Temperature programmed surface reaction (TPSR) and Programmed Temperature Oxidation (TPO) post-catalytic, besides the application of the catalysts in the dry reforming of CH4 combined with O2 for 20 h. It was observed that the perovskite phase, LaNiO3, was obtained in samples prepared by both synthesis methodologies, using high calcination temperatures (~800 ° C) and low cerium contents. The effect of the presence of the perovskite phase and / or cerium on the synthesized solids allowed for average sizes of smaller crystals and similar values, promoting high conversion values of methane and carbon dioxide and H2/CO ratio. In addition, catalysts from the catalytic precursors containing the perovskite type crystalline phase showed higher selectivity to H2 and CO when compared to other materials. It is noted that the synthesis methods provide catalysts with high nickel content, greater resistance to the sintering processes due to small variation of the size of their crystals after the catalytic test. It was found that the catalysts with higher CH4 and CO2 conversions also produced a higher amount of coke, however, there were no indications of catalyst deactivation, which is attributed to the presence of lanthanum and cerium species that act as carbon scavengers. Also verified for the NLS8 catalyst, prepared by wet impregnation, presenting similar characterizations and catalytic aspects to the NLP sample, synthesized via the sol-gel route, indicating a simpler alternative way to obtain Ni/La2O3 type catalysts. The combination of the sol-gel methodology and the presence of the LaNiO3 crystalline phase allowed the formation of catalysts of good stability and catalytic activity.

Thèses
1
  • ROBERTA NATÁLIA CARNEIRO DA SILVA CARVALHO
  • ANALYTICAL STRATEGIES USING C18 DISCS TO DETERMINE METAL TRAITS IN WATER SAMPLES USING X-RAY FLUORESCENCE SPECTROMETRY BY DISPERSIVE ENERGY
  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • VANIA PALMEIRA CAMPOS
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • ICARO THIAGO ANDRADE MOREIRA
  • LEILA MARIA AGUILERA CAMPOS
  • Data: 25 janv. 2018


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  • Natural waters have been deposited with elements potentially toxic to humans and to various forms of life. The toxicity of these elements in water varies, among other aspects, with the present concentration. In this work, two analytical methods are presented for determining the concentration of metals in environmental samples of river water, groundwater and tap water by X-ray fluorescence by dispersive energy (EDXRF), after the solid phase extraction procedure. For the preconcentration procedure, the 1-(-2-thiazolylazo) -2-naphthol (TAN) reagent was used for complexing the analytes with subsequent retention of the complexes on C18 discs for direct determination on the solid support by EDXRF. The first work had univariate optimized pH, flow and sample volume for uranium extraction on C18 disk. The instrument voltage parameters of the tube, the measurement time and the current used were also optimized. To evaluate the accuracy, the relative standard deviation (RSD) of the measurement of 10 standards was used, with a value of 10%. The limit of quantification (LQ) was 10.0 μg L-1 . The accuracy of the developed method was evaluated by applying addition and recovery tests of the analyte in real samples and analysis of reference material with recoveries varying between 98 and 117%. Accuracy and sensitivity were adequate for analysis of water samples. In the second work, a complete factorial design 23 was applied to optimize the pH, flow and sample volume for preconcentration Cd, Co, Cu, Fe, Hg, Ni, V and Zn on C18 disks. From the optimized system, calibration curves with good linear correlation were obtained for Co, Cu, Fe, Ni and Zn, and the main performance parameters as quantification limit, μg L-1 (17, 13, 17, 10 and 1), RSD,% (9, 9, 12, 10, 2 and 12), sensitivity and accuracy were suitable for determination in water samples. The accuracy of the method was verified through analysis of water reference material, with no significant difference between the value obtained and the certificate being observed for a 95% confidence level. Futhermore, addition and recovery tests were performed on potable water samples with recoveries between 84 and 107%. The two methods were applied in groundwater, river water and tap water analysis collected in the city of Caetité, Bahia, Brazil. For the samples evaluated, the concentrations of the metals U, Co, Cu, Fe, Ni and Zn were below the maximum values established by the CONAMA legislation (Resolution 357 of March 18, 2005 and Resolution 396 of April 3, 2008 ) and the Ministry of Health (Ordinance No. 2914, of December 12, 2011), offering no risk for human consumption.

2
  • CAIO LUIS SANTOS SILVA
  • PLATINUM CATALYST DEVELOPMENT SUPPORTED ON CARBONACE MATERIALS FOR WGS REACTION
  • Leader : MARIA DO CARMO RANGEL SANTOS VARELA
  • MEMBRES DE LA BANQUE :
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • ROBERT NEWTON DA SILVA HENRIQUES MAGALHÃES
  • CESÁRIO FRANCISCO DAS VIRGENS
  • Data: 28 févr. 2018


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  • In the last years, the interest for the water gas shift reaction (WGSR) have increased especially due to the need of supplying energy through technologies cleaner and more efficient, and to its role in fuel cells. In order to obtain alternative materials for this reaction, catalysts made of platinum supported on functionalized carbon matrices, such as carbon nanotubes, activated carbons and nanostructured carbon were studied in this work. Activated carbon was obtained by chemical activation, while nanostructured carbon was synthesized by the sequential template technique and commercial carbon nanotubes were employed. These different carbonaceous materials were purified and functionalized with hydrogen, diethylamine and acetic acid. Platinum was added to the supports via incipient wet impregnation. The catalysts were evaluated in the WGSR at 1 atm and reaction rates, activation energies and reaction orders were determined using a process gas containing 6.8% CO, 8.5% CO2, 37.0% H2, 22.0 H2O, simulating a reformer of a fuel cell. Based on all characterizations carried out in this study, it was concluded that the purification and functionalization methods employed in the work promoted: (i) the reduction of the thermal stability of the solids; (ii) the elimination and/or reduction of impurities; (iii) the incorporation of surface functional groups and (iv) the decrease in the degree of crystallinity and the specific surface area of the supports. These results are mainly due to the creation of defects in materials due to the insertion of the surface groups and/or partial/total collapse of the porous structures. All the catalysts showed platinum contents close to the nominal value and were active in the WGS reaction. It was found that the type of carbonaceous material and the type functionalization substantially influenced the catalytic activity of platinum. In the series of catalysts supported on carbon nanotubes, the functionalization had a negative influence on the performance of the samples. On the other hand, in the series of activated carbons and nanostructured carbons there was an increase in catalytic activity due to purification and functionalization processes.

3
  • ANALU PIRES SANTOS
  • DISPERSIVE MICRO-EXTRACTION IN LIQUID PHASE WITH TEMPERATURE CONTROL FOR DETERMINING CADMIUNM IN FOOD SAMPLES

  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • MADSON DE GODOI PEREIRA
  • MARCOS DE ALMEIDA BEZERRA
  • MARIA DAS GRACAS ANDRADE KORN
  • RODOLFO DE MELO MAGALHAES SANTANA
  • Data: 21 mars 2018


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  • In the present work, two methods were proposed for the preconcentration of cadmium using microextraction with ionic liquid assisted by ultrasound and controlled temperature (TC-IL-LPME) and microextraction with solidified floating organic droplet (SFODME). The method employing TC-IL-LPME consists of dispersing the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate (1-Hmim [PF6]) in the aqueous phase was performed by heating in an ultrasonic bath, followed by cooling in an ice bath. After centrifugation, the enriched phase was dissolved in acidic ethanol solution to reduce viscosity and the cadmium content was determined using graphite furnace atomic absorption spectrometry (AAS GF). The reagent was not used as a complexing agent. Under optimized conditions, the method had a detection limit of 0.6 ng L-1 and enrichment factor of 24. The accuracy of the method was evaluated through the analysis of the certified reference material of brown bread (BCR-191) and recovery test ranging from 95.8% to 105%. The method was applied in the determination of cadmium in samples of breads and biscuits. The method in which SFODME was used is the dispersion in thin droplets of the extracting solvent 1dodecanol, by means of the dispersing solvent ethanol, for the extraction of the CdAPDC complex. The system is then centrifuged for phase separation and the drop is frozen to facilitate removal. After dissolution of the nitric acid enriched phase in ethanol, it was measured by flame atomic absorption spectroscopy (FAAS). Under optimized conditions, the method had a detection limit and preconcentration factor of 0.69 g L-1 and 21, respectively, to test the accuracy of the method, the recovery results ranged from 102% to 109%. The method was applied in the determination of cadmium in farinaceous foods. The proposed methods are presented as simple, low cost, ecological and very sensitive alternatives for the determination of cadmium in farinaceous foods and derivatives.

4
  • ANA CARLA DIAS REGIS
  • EVALUATION OF THE CHEMICAL COMPOSITION OF THE PARTICULATE MATERIAL MP2,5. BY COMPREHENSIVE TWO-DIMENSIONAL GAS CHROMATOGRAPHY
  • Leader : JAILSON BITTENCOURT DE ANDRADE
  • MEMBRES DE LA BANQUE :
  • GISELE OLIMPIO DA ROCHA
  • JAILSON BITTENCOURT DE ANDRADE
  • MARIA ELISABETE MACHADO
  • MARTA VALERIA ALMEIDA S. DE ANDRADE
  • ZENILDA DE LOURDES CARDEAL
  • Data: 26 mars 2018


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  • This work qualitatively characterized the compounds present in 14 samples of particulate material (MP2.5) collected in the years 2010 and 2013 at a bus station in Salvador, BA using comprehensive two-dimensional gas chromatography with mass spectrometry detectors (GC×GC/TOFMS). The predominant chemical classes were hydrocarbons (saturated and unsaturated), poly oxygenated species (acids, esters, aldehydes, ketones, alcohols, ethers) and compounds with heteroatoms of nitrogen and sulfur. All were identified based on retention time, spectral comparation and retention index with linear temperature programming (LTPRI). A similar profile for these samples was verified through statistical tests, which demonstrated the homogeneity in the MP2.5 profile analyzed. Two samples from different years were selected for a more detailed study to verify the potential of the two-dimensional technique regarding the ability of identification and separation of compounds. In this stage, it can be observed that compounds of great environmental importance, such as many HPA's, with each other and with other species in the 1D, for example benzo[a]anthracene, chrysene and triphenylene, which were identified thanks to the presence of 2D. Also, benzophenone, considered as a possible carcinogenic to humans, was identified and confirmed by interferon-free LTPRI. Similarly, other hazardous air pollutants such as acetamide, caprolactam were detected and confirmed by LTPRI. Some sulfur compounds that may be of great relevance in the acidification of PM and composition were detected and discussed for the first time. The use of GC×GC/TOFMS provided greater peak capacity, selectivity, chromatographic structuring and spectral purity, these characteristics allied to the spectral deconvolution tool and the use of LTPIR provided a good characterization of the samples with a large number of compounds tentatively identified and pointed the way for further research in the understanding of MP training and composition

5
  • AUGUSTO CEZAR MAGALHÃES ALELUIA
  • ANALYTICAL STRATEGIES FOR THE DETERMINATION OF TOXIC AND ESSENTIAL ELEMENTS IN DRUGS AND BIOLOGICAL MATRICES
  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • SERGIO LUIS COSTA FERREIRA
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • WALTER NEI LOPES DOS SANTOS
  • LIZ OLIVEIRA DOS SANTOS
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • Data: 8 juin 2018


  • Afficher le Résumé
  • The essential and toxic elemental research in pharmaceutical formulations and biological matrices requires the correct application of several analytical techniques. It’s extremely important the investigation of these analytes, since the high concentrations may develop toxic reactions, which compromises the health of individuals. Few is known about trace elements in pharmaceuticals, which prevents the verification of the risk associated with the consumption of these products. Chemical elements essentially toxic, as As, Cd, Hg and Pb directly compromise physiological functions of vital organs, being extremely dangerous. Other elements, that are essential to human health, participate in normal biochemical reactions, they also can develop a toxic profile, when they are present in high concentrations, exceeding acceptable limits. It was performed an investigation study in allopathic medicines from the determination of Cu, Fe, Mo, Ni, Zn, As, Cd and Pb using ICP-MS. Data were analysed through principal component analyses (PCA) and hierarchical cluster analyses (HCA). It was found two outliers samples, which revealed the highest concentrations of Fe, Ni, Cu, Zn, As and Mo, when compared to the others. Except these two, the other samples showed the lowest levels of Cd and Pb, which not exclude the development of a complete study. Later, it was proposed a method to sequential determination of Cd and Pb using HR-CS GFAAS in also allopathic medicines. It was used a full factorial design 23 to optimize the furnace conditions, which variables were Cd pyrolysis and atomization temperatures, and Pb atomization temperature. Limits of detection (LD) e quantification (LQ) were obtained for Cd and Pb, being 4 and 13 ng g-1, 50 and 165 ng g-1, respectively. Ten samples were analysed and the concentrations of Cd and Pb found in the interval of 8 ± 1 to 45 ± 2 ng g-1 and 13 ± 2 to 448 ± 26 ng g-1, respectively, were under acceptable limits established by Brazilian and US Pharmacopeia (maximum of 5 µg day-1). After this, it was developed an analytical strategy to Co determination in human urine using HR-CS GFAAS. The aim of this study was the evaluation of Co levels, which is eliminated in urine. Co, even as an essential element, can play toxic reactions when it is found in high concentrations. A full factorial design 23 was also applied, but now for the evaluation of sample preparation conditions, considering the variables: quantity of H2O2, time of sonication and temperature of sonication. The accuracy way verified through spike test, which values of recuperation were obtained in the interval of 99,0 and 105,9 %. LD and LQ were 0,541 and 0,676 µg L-1, respectively. Five urine samples were analysed and the Co levels determined were under the daily exposure limit established by International Council for Harmonisation (ICH), which value is 50 µg. This research work was developed according to national (Brazilian Pharmacopeia) and international (USP, ICH and EMA) guidelines when it comes to acceptable limits of inorganic impurities in pharmaceutical products and daily exposure limits to chemical elements.

6
  • REBECA MORAES MENEZES

  • Microextraction methods in liquid phase for determination spectrometric analysis of mercury in samples of fish oil

  • Leader : WALTER NEI LOPES DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • WALTER NEI LOPES DOS SANTOS
  • LEONARDO SENA GOMES TEIXEIRA
  • ANDERSON SANTOS SOUZA
  • GEOVANI CARDOSO BRANDÃO
  • VALFREDO AZEVEDO LEMOS
  • Data: 5 juil. 2018


  • Afficher le Résumé
  • Current trends in analytical chemistry are leading to the development of methods that provide miniaturization and reduction in the generation of compounds harmful to the environment. In this work, two methods were proposed for the preconcentration of mercury using temperature controlled-ionic liquid-dispersive liquid-liquid microextraction and vortex-assisted (TC-IL-LPME) and liquid-liquid dispersive microextraction with the solidification of the floating organic drop DLLME-SFOD). In both methods, detection was performed using cold vapor atomic absorption spectrometry (CV AAS), and the ammonium pyrrolidine dithiocarbamate (APDC) reagent was used as a complexing agent for Hg2+. The developed TC-IL-LPME method consists in dispersing the ionic liquid 1-butyl-3- methylimidazolium hexafluorophosphate ([Bmim][PF6]) in the aqueous phase by vigorous vortexing, followed by heating and cooling in an ice bath. After centrifugation, the enriched phase was dissolved in an acid solution to reduce viscosity, and the mercury was quantified in this mixture. Under optimized conditions, the method had a detection limit of 0.045 μg L-1 , a limit of quantification of 0.15 μg L-1 and an enrichment factor of 54. The method was applied to the determination of mercury in fish oil samples. In the method using DLLME-SFOD, 1-dodecanol was used as extraction solvent of the Hg-APDC complex. The dispersion of the organic solvent in fine droplets was promoted by the solvent dispersant ethanol and magnetic stirring. The drop was then frozen to facilitate removal. After dissolution with nitric acid, the mercury content was determined. Under optimized conditions, the method showed a limit of detection and quantification of 0.067 μg L-1 and 0.22 μg L-1 , respectively. The method was applied to the determination of mercury in fish and crustacean. The two methods were successfully applied in the preconcentration of mercury in food samples and presented as versatile, ecological and very efficient alternatives.

7
  • JORSANETE PASSOS CARDOSO

  • Study of dynamics of dinitropirene interactions in complex matrices

  • Leader : SERGIO LUIS COSTA FERREIRA
  • MEMBRES DE LA BANQUE :
  • ANTONIO FERNANDO DE SOUZA QUEIROZ
  • JORGE MAURICIO DAVID
  • OLIVIA MARIA CORDEIRO DE OLIVEIRA
  • SERGIO LUIS COSTA FERREIRA
  • VANIA PALMEIRA CAMPOS
  • Data: 27 juil. 2018


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  • For a long time, we have produced a range of substances to meet our needs. However, a good number of these compounds end up being harmful (toxic) to the environment and human. Due to their physico-chemical properties, these compounds interact with the ambient and can even be transferred to other compartments through physical, chemical and biological processes. In this activity, the substance produced by humanand released into the environment, can propagate in chains, taking the toxic compound, unknown to the organism, and therefore called xenobiotic, to numerous pathways of transformation that make it difficult to determine. Some of these toxins interact in such a way with the matrix in which it is associated, which for many times become difficult to determine. In order to avoid some losses in the analysis of the xenobiotic (analyte of interest), it is necessary to evaluate mainly the characteristics of its ligands and the type of intermolecular interactions that dominates these compounds and the physico-chemical factors that are influenced by them. These observations contribute to the choice of techniques and analytical methods that can accurately and robustly determine the presence of the analyte in the matrix. Many of the organic compounds, especially polycyclic aromatic hydrocarbons (PAHs) and their derivatives (nitro-HPA), are ubiquitous, carcinogenic and mutagenic, therefore, they can be absorbed through the diet. The isomers 1,6 and 1,8 belong to the nitro-HPA group have a high mutagenic potential. In addition to these characteristics, the literature review has made it possible to suggest that the 1,6 and 1,8 DNP isomers according to their physicochemical characteristics may contribute to neurodegenerative diseases such as Alzheimer, Parckinson, depression and diabetes, through its degradation forming reactive oxidative and nitrosoactive species. We suggest further studies on the possible metabolic pathways in the gastrointestinal tract, evaluating the performance of the intestinal flora in the oxidation-reduction processes of these compounds.

8
  • ROBSON CARLOS DE ANDRADE
  • ACTIVATED CARBONS DERIVED FROM MANGO FRUIT (Mangifera indica L.)  FOR THE CAPTURE OF CO2 AND VOLATILE ORGANIC COMPOUNDS (VOCs).

  • Leader : HELOYSA MARTINS CARVALHO ANDRADE
  • MEMBRES DE LA BANQUE :
  • HELOYSA MARTINS CARVALHO ANDRADE
  • ARTUR JOSE SANTOS MASCARENHAS
  • ADRIANE VIANA DO ROSARIO
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • RODRIGO DE PAULA
  • Data: 27 juil. 2018


  • Afficher le Résumé
  • Activated carbons were prepared from Mango (Mangifera Indica L.) fruit seed shells and used as CO2 capture adsorbents. The pyrolysis of the biomass was previously undertaken and the chemical activation of the carbonized material was performed by using KOH. The activated carbons showed high surface areas (883-2994 m2 g-1) and different pore size distributions. The CO2 capture studies were undertaken by TG and adsorption capacities as high as 9.53 % were achieved, at 40 ºC. Higher adsorption capacities were related to highly basic surface of micropores derived from the chemical interactions between the char obtained by pyrolysis of the biomass and the activating agent. A second preparation route was also used, so that the starting material was hydrothermally treated at 180 or 250 ºC for 5h and the obtained hydrochars were activated with KOH solutions. The carbon samples were characterized by SEM, EDX, TG/DTA, Raman spectroscopy and physical adsorption for textural analysis. The adsorption capacity and adsorption cycles were investigated by TG. The hydrochars presented spherical morphology. The results indicate that the adsorption capacity of the activated carbons is directly related to their Dubinin-Astakhov micropore surface areas and the microporous volumes determined by NLDFT. The adsorption of acetone vapor showed a pseudo-first order kinetics and both external and intra-particle transport contributed for the overall process. Highly efficient and stable acetone vapor removal was observed over the activated carbons after 5 cycles.

9
  • CRISTIANE GOMES ALMEIDA
  • The role of graphene oxide (GO) and the influence of zinc on photocatalytic hydrogen generation using binary (GO-CdS and GO-Cd1-xZnxS) and ternary photocatalysts (Pt-GO-CdS and Pt-GO-Cd1- xZnxS
  • Leader : LUCIANA ALMEIDA DA SILVA
  • MEMBRES DE LA BANQUE :
  • ADRIANE VIANA DO ROSARIO
  • LUCIANA ALMEIDA DA SILVA
  • MARCUS VINICIUS SANTOS DA SILVA
  • ROBERTO RIVELINO DE MELO MORENO
  • SILVIA MARIA DA SILVA EGUES
  • Data: 30 juil. 2018


  • Afficher le Résumé
  • Hydrogen obtained from water is an attractive vector of energy since it can be produced by renewable and inexhaustible sources such as solar energy, water and biomass. A new process based on water splitting assisted by photocatalytic semiconductors, now allied to graphene which exhibits unique structural, electronic and charge carrier properties, is considered a promising alternative. In this sense, the photocatalytic activity of binary (GO-CdS and GO-Cd1-xZnxS) and ternary (Pt-GO-CdS and Pt-GO-Cd1-xZnxS) hybrid systems was evaluated in the generation of hydrogen. For this, different methods of synthesis, sonochemical and thermal, were used to prepare composites with CdS and graphene oxide (GO), as well the insertion of zinc in the CdS structure in different ratios was also evaluated. The results indicate that graphene oxide (GO) is reduced during the induction time of the hydrogen generation reaction, yielding RGO, which also acts as a cocatalyst. Among evaluated materials, the ternary composite, Pt(RGO/CdSTT), obtained by thermal method, has exhibited the best performance, due to the higher crystallinity of hexagonal CdS, higher dispersion of GO when introduced during the synthesis and higher efficiency in the photoreduction process of GO to RGO. The combination of these factors resulted in a synergistic effect of platinum with reduced graphene oxide as cocatalysts, yielding a hydrogen production rate of 651.6 μmol gcat-1 h-1. The zinc insertion in the CdS wurtzite structure has improved the photocatalytic activity with respect to the sonochemical CdS by more than 20 times for the binary system, GO/SZ2, and about 12 times for the ternary system, Pt(GO/SZ2). In this case, the best photocatalytic activity may be associated to the higher degree of graphite oxidation (O/C = 1.72) in the GO/ZS2 sample (Cd:Zn:S ratio 1:2:4), which facilitates the exfoliation process, resulting in fewer stacked graphene oxide sheets. The heat treatment of the GO/SZ2 sample resulted in a significant increase of the crystallinity as well as expressive increase in the photocatalytic activity, 386.65 μmol gcat-1 h-1 for GO/SZ2TT and 463.68 μmol gcat-1 h-1 for Pt(GO/SZ2TT), in relation to the sample GO/SZ2, 114.87 μmol gcat-1 h-1.

10
  • FABIANY CRUZ GONZAGA
  • Evaluation of high surface area Pd / α-alumina catalyst for application in catalytic combustion reaction of methane
  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • JAIME SOARES BOAVENTURA FILHO
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • RAILDO ALVES FIUZA JUNIOR
  • SORAIA TEIXEIRA BRANDAO
  • TIAGO VINICIUS ALVES
  • Data: 30 juil. 2018


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  • Natural gas is a type of fossil fuel being the most important energy source in today's society. Natural gas is composed mostly of methane and improvements in the efficiency of the combustion reaction contribute mainly to the emission reduction of nitrogen oxides (NOx) compounds and unburned hydrocarbons. The noble metals are species applied as the active phase of the catalyst, with emphasis on Pd. The carrier has a significant impact on the catalyst characteristic, with the aluminas being highlighted for the catalytic combustion of methane. The α-alumina is an interesting material for application as a support in the catalytic combustion due to thermal stability. The present work consists in obtaining α-alumina support with high specific surface area applying the combustion method and its impregnation with palladium, investigating the effect of this support on the catalytic activity of the material obtained by comparing the commercial α-alumina support catalysts with reduced specific surface area impregnated by the same method. The characterization of the composites was XRD, XRD with temperature ramp in reaction medium, specific area measurement (BET), EDX, SEM and the catalytic evaluation was performed by thermoprogrammed surface reaction (TPSR) and thermoprogrammed oxidation (TPO) with 3 uninterrupted heating and cooling cycles. The combustion method allowed to obtain crystalline α-alumina with specific surface area of 263 m2 .g-1. This prepared support impregnated the Pd differently with respect to the catalyst obtained by impregnation of commercial α-alumina. The TPSR and TPO indicated that specific low surface area α-alumina exhibit slightly better catalytic activity but the ability to stabilize the lower PdO species. The high surface area α-alumina catalyst obtained showed higher stability of the active phase, indicating a longer life of the catalyst compared to the reaction medium.

11
  • VANIELE SOUZA RIBEIRO
  • Quantification and evaluation of inorganic constituents present in urban dust: a study of the cities of Jaguaquara and Salvador, Bahia, Brazil
  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • WALTER NEI LOPES DOS SANTOS
  • VANIA PALMEIRA CAMPOS
  • MARIA DAS GRACAS ANDRADE KORN
  • TATIANE DE ANDRADE MARANHÃO
  • KARINA SANTOS GARCIA
  • Data: 1 août 2018


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  • In this work, inorganic constituents of fractionated urban dust samples (A <63 μm, 63 μm> B> 38 μm and C <38 μm) were determined and evaluated from the cities of Jaguaquara (27 samples) and Salvador (54 samples), Bahia state, Brazil. The samples preparation procedure was optimized using Box-Behnken design. The study showed that the best compromise of microwave-assisted extraction of the chemical elements would use the volumes of 1.0 mL of HNO3, 1.5 mL of HCl and 1.3 mL of H2O2, for the determination of Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Sb, V and Zn using methods based-inductively coupled plasma (ICP). Accuracy and precison were evaluated through analysis of the certified reference material of road dust (BCR 723), obtaining concordant values between 80 and 112%. The precision was expressed as relative standard deviation (RSD), being better than 3.74% (n = 3). The values of limits of quantification (LoQ) varied between 0.14 (Sb)and 0.009% (Fe). The enrichment factor (EF) values showed that the fraction C (<38 μm) was the most enriched by elements. Based on values of geoacumulation index (Igeo), it was verified that urban area of Salvador was more environmentally impacted by inorganic constituents than Jaguaquara. The multivariate data analysis and Pearson's correlation revealed that inorganic constituents concentrationsin dust collected Jaguaquara and Salvador cities,can come from both natural and anthropic sources. For urban area of Salvador, the main anthropic source was related to traffic, for Cd, Co, Cu, Mn, Mo, Ni, Pb, Sb and Zn. The risks coefficients for inorganic constituents that obtained anthropogenic action was calculated, and the non-carcinogenic risk (HQ) and hazard ratio (HI) indicated that there are no possible adverse human health effects in relation to the contaminating chemical elements of the environments, for the two cities. The determination of K, P, S, Si and Ti in12 samples was performed using direct solids analysis by dispersive energy X-ray fluorescence spectrometry (EDXRF). The obtained LoQ ranged from 0.002% (S) to 0.63% (Si). The methodology showed good accuracy through the analysis of the CRMof Montana I Soil (NIST 2710), which presented concordant values between 81 and 90%, and RSD better than 3.7% (n = 3). The principal component analysis (PCA) pointed out possible sources related to vehicular traffic in Salvador city, for P and S concentrations. Potassium and Ti originated from both natural sources (Jaguaquara), as anthropic (Salvador). The concentrations of Si were related to soil geology of Jaguaquara city. It was also proposed, a methodology of speciation chemical analysis for As and Sb by slurrysampling and detection employing hydride generation atomic absorption spectrometry (HG-AAS), using the fast sequential mode (FS). The use of Doehlert matrix and desirability function, it was possible to find the optimum conditions for the generation of hydrides (HCl 1.0 mol L-1 and NaBH4 0.9% m v-1). The accuracy of the analytical method was evaluated by fly Ash (BCR 176R), addition and recovery test for inorganic species of As and comparison of the independent method for determination of Sb. Therefore, the determinations of total concentrations and theirs inorganic species showed good accuracy (80-101%). The RSD found was better than 4.6 % (n = 3). The obtained LoQs were 0.23 mg kg-1 for As and 1.03 mg kg-1 for Sb. The methodology was applied in 08 urban dust samples, for the lowest fraction (<38 μm), which presented concentrations for the highest pentavalent inorganic species (iAs5+ and iSb5+) in relation to trivalent species (iAs3+ and iSb3+), which are regarded as more toxic, for both elements. The values of EF and Igeo showed that there is anthropic source contribution for As and Sb total concentrations in samples ofthe urban area of Salvador. In this work, the results
    found allowed to draw the profiles of the cities of Bahia state in relation to the inorganic constituents in dust samples, suggesting a direct relation between the occurrence of the elements and the greater urbanization, through the associated contribution to the traffic, mainly in Salvador.

12
  • QUEILA OLIVEIRA DOS SANTOS
  • ESTRATÉGIAS ANALÍTICAS PARA ANÁLISE DE ESPECIAÇÃO DE ARSÊNIO INORGÂNICO EM AMOSTRAS AMBIENTAIS

  • Leader : JAILSON BITTENCOURT DE ANDRADE
  • MEMBRES DE LA BANQUE :
  • JAILSON BITTENCOURT DE ANDRADE
  • LUCIANA ALMEIDA DA SILVA
  • MARIA GORETI RODRIGUES VALE
  • MARTA VALERIA ALMEIDA S. DE ANDRADE
  • SERGIO LUIS COSTA FERREIRA
  • WALTER NEI LOPES DOS SANTOS
  • Data: 23 août 2018


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  • The present work involves in the development of analytical methodologies for analysis of inorganic arsenic speciation in environmental samples using hydride generation atomic absorption spectrometry (HG AAS). Two studies were carried out considering this approach. The first consisted of the development of an on-line preconcentration system for the determination of As(III) and As total in seawater samples. The method is based on the selective reaction between As(III) and the ammonium pyrrolidinedithiocarbamate complexing reagent (APDC) in acid medium, followed by sorption of the complex formed in a polytetrafluoroethylene (PTFE) minicolumn and elution with a 2.0 mol L-1 hydrochloric acid solution. A complete factorial design and Doehlert matrix were applied to optimize the following experimental variables: Sample acidity, APDC concentration and sample rate. The limits of detection and quantification established for As(III) were, respectively, 0.02 and 0.07 μg L1 . The total As content was determined following a step of reducing As(V) to As(III) using thiourea in acid medium. The limits of detection and quantification found for As total were, respectively: 0.03 and 0.09 μg L-1 . The precision, estimated as the relative standard deviation (RSD), was 5.3%. Accuracy was confirmed by analysis of a certified seawater reference material (CASS-4). The proposed system was applied in the speciation of inorganic As in seawater samples collected in Todos os Santos Bay, Salvador, Bahia, Brazil. The concentration of As(III) found in the analyzed samples ranged from 0.09 to 0.51 μg L-1 , and the total As content varied from 0.20 to 0.66 μg L-1 . The second work involved the development of a method using suspension sampling for the determination of As(III) and As in sediment samples. A complete factorial design and Doehlert matrix were applied for the optimization of the following experimental variables: The limits of detection and quantification found for As(III) were, respectively: 0.01 μg g-1 and 0.05 μg g-1 . The precision expressed as RSD was 3.4 %. The method was applied to the analysis of a certified sediment reference material (NIST 1646a) and sediment samples collected in Bahia de Todos os Santos, Salvador, Bahia, Brazil. The As(III) content in the analyzed samples ranged from 3.5 to 5.5 μg g-1 and the total As content varied from 7.3 μg g-1 to 9.4 μg g-1 .

13
  • FELIPO OBED CORREIA
  • Determination and evaluation of inorganic constituents present in particulate material collected indoors in Salvador, Bahia, Brazil

     
  • Leader : RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MEMBRES DE LA BANQUE :
  • GISELE OLIMPIO DA ROCHA
  • JEANCARLO PEREIRA DOS ANJOS
  • LEONARDO SENA GOMES TEIXEIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • WALTER DOS REIS PEDREIRA FILHO
  • Data: 24 août 2018


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  • In the present work, the evaluation of the indoor air quality of apartments of the city of Salvador / Bahia, Brazil was approached. Samples of airborne particulate matter (APM) were collected in 74 indoor samples of total suspended particles (TSPind) and 16 outdoor samples (TSPout), in eight apartments of five neighborhoods of urban area of Salvador. Concentrations of TSPind ranged from 4.0 to 110.6 μg m-3, with a mean of 25.2 ± 23.4 μg m-3. Already with concentrations of TSPout varied between 4.6 and 40.6 μg m-3, with a mean of 21.9 ± 10.1 mg m-3. The analyzes in TSP samples were also evaluated according to a seasonal variation. The chemical characterization of the TSP samples was performed through inductively coupled plasm based methods, as optical emission spectrometry (ICP OES) and mass spectrometry (ICP-MS). The concentrations of Cd, Co, Cu, Fe, Mg, Mn, Ni, Pb, S, Sb and V were determined in addition to the chemical speciation analysis of As and Sb sequentially in samples of external (TSPout) and internal (TSPind) particulate matter of the cities of Aracaju (SE) and Salvador (BA), using hydride generation atomic absorption spectrometry (HGAAS). Simultaneous experimental design techniques were applied for the optimization of procedures for the samples preparations, spectrometer operational conditions and hydride generation. The concentrations of the inorganic constituents in the TSPind samples varied from ≤ 0.49 (Ni) to 8040 ng m-3 (Mg). For the TSPout samples the elements concentration varied between 0.49 (Ni) and 4198 ng m-3 (Mg). Chemometric tools (Pearson’s correlation, PCA and HCA) enabled the identification of six main sources of emission (marine aerosol, steel industry, burning of fossil fuels, resuspension of the soil, welding of metal alloys and vehicular traffic) which contributed to the chemical composition of PM in Salvador apartments. In all analyzed samples, total concentrations of As and its inorganic species were below the limit of quantification (LoQ) (<0.32 ng m-3) of the analytical method. On the other hand, it was possible to quantify the concentrations of total Sb and its inorganic species in all the analyzed samples, with a predominance of the Sb3+ species, attributing probably the presence of Sb in the samples to vehicular traffic
     
     
14
  • SELMO QUEIROZ ALMEIDA
  • Verification of adulteration of automotive gasoline with solvents using gas chromatography and chemometric tools

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • FÁBIO SANTOS DE OLIVEIRA
  • JORGE MAURICIO DAVID
  • LEILA MARIA AGUILERA CAMPOS
  • LEONARDO SENA GOMES TEIXEIRA
  • LUCIENE SANTOS DE CARVALHO
  • Data: 5 oct. 2018


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  • The regulatory conjuncture in the fuel sector, established by the National Agency of Petroleum, Natural Gas and Biofuels - ANP, has still presented difficulties, mainly for the identification of problems of adulteration of fuels, due to the addition of solvents in automotive gasoline. In this work, a method was developed to verify the adulteration of commercial gasoline (type C gasoline, available in Brazil and containing anhydrous ethanol), based on the combination of gas chromatography data equipped with flame ionization detector (CG-DIC) associated to multivariate analysis tools. The multivariate analysis tools used were Principal Components Analysis (PCA), Discriminatory Analysis by Regression by Partial Least Squares (PLS-DA), Quantitative Analysis by multivariate calibration PLS-1, to obtain models associated with the presence of adulterant solvents in gasoline. In order to construct the multivariate classification and calibration models, gasoline was used according to current specifications, which were collected at gas stations in the state of Bahia and synthetic mixtures composed of gasoline with solvents of turpentine, thinner and kerosene, obtaining a total of 120 samples and synthetic mixtures. From these samples, 80 were randomly selected for the calibration set and 40 were selected for the prediction set. The PCA and PLS-DA and PLS-1 regression models were developed in the software The Unscrambler version 9.1 and evaluated using gasoline type C samples with these solvents for two matrices: the first matrix with the composition data (alkanes (C4-C14), ethanol and the main aromatics (benzene, toluene, m-xylene, p-xylene, o-xylene)) and the second matrix with the same data and adding the results of the specific mass at 20 °C and atmospheric distillation. The multivariate PCA tool was used to classify the adulterated and unadulterated samples, also verifying the variables of greater statistical influence. The chemometric evaluation using partial least squares (PLS) was performed in a qualitative and quantitative way, aiming to identify and quantify the adulterants present. The PCA results, by the Scores and Loadings graphs, visually classified the adulterated and unadulterated samples and the most statistically significant variables for the matrix Parafinas (ethanol and toluene) and for matrix Parafinas_MD (specific mass, 50% evaporated distillation, PFE distillation and ethanol). The proposed PLS-DA qualitative multivariate model presented a 100% accuracy when classifying the samples of the gasolines group without adulteration, while 90% accuracy was obtained for the total of 120 samples and mixtures analyzed in the classifications of adulterated and unadulterated gasolines. Concerning the quantification of adulterants using PLS-1, the results obtained evidenced the mean squared errors of prediction (RMSEP) for the gasoline concentrations of both matrices, which were below 5% (v/v), depending of the composition of the synthetic mixtures, and for the Parafina matrix, the errors were up to 2.4% (v/v). These results showed that the combination of CG-DIC/PCA/PLS-DA/PLS-1 may be an alternative for routine monitoring of fuel adulteration, using equipment available in fuel quality control laboratories.

15
  • VITOR HUGO MIGUES
  • Use of CLAE-DAD, UV and multivariate analysis in the quality control of medicinal plants and herbal products
  • Leader : JUCENI PEREIRA DE LIMA DAVID
  • MEMBRES DE LA BANQUE :
  • ADEMIR EVANGELISTA DO VALE
  • ERIKA MARIA DE OLIVEIRA RIBEIRO
  • JORGE MAURICIO DAVID
  • JUCENI PEREIRA DE LIMA DAVID
  • VALERIA BELLI RIATTO
  • Data: 17 oct. 2018


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  • Scientific researchs has pointed out the presence of various irregularities in herbal products and adulteration of herbal drugs that compromise efficacy and endanger the consumer health. One of the causes for this scenario has been the fact that the industries responsible for the manufacture of these products are basically small businesses that work precariously and the research to evaluate the safe use of herbal and phytotherapeutic plants in Brazil is still scarce, compromising the supervision of trade by the appropriate agencies. Since the poor quality of a product can interfere the pharmacological action recommended for the species, potentiating undesirable effects, and many native medicinal plants suffer threats that can lead to extinction, research evaluating the quality of herbal products and establishing priorities of conservation for medicinal plant species are essential. Thus, the aim of this project is to develop a methodology by HPLC, through the analysis of phenolic compounds, to obtain a fingerprint of the vegetal material marketed in natura and as phytotherapics such as Rhamnus purshiana (sacred shell), Schinus terebinthifolius (aroeira), Glycine max (soy isoflavone), Plantago ovata Forssk (plantago) and Cassia angustifolia (sene), at the state of Bahia. The analyzes by HPLC shows the technique importance for the fingerprint determination of each vegetable. In addition, it can be evidenced that some species, such as aroeira and sacred shell, present divergent peaks when compared with the standard vegetal material. On the other hand, the soybean marketed in the state of Bahia presents diverse concentrations of the most diverse metabolic. Such data is extremely importance to evaluate the safety of the herbal product consumed by the population. In addition, the use of the chemometric technique associated with other analyzes was odd to evaluate the effectiveness of the methodology and to verify the combination or discrepancy of the samples. Thus, the obtained results in this work demonstrates that the methodology satisfies the validation parameters required by ANVISA Resolution RE 899, May, 2003. The correlation coefficients of the linear regression analyze were close to 1. The method presented good repeatability and satisfactory recovery, besides being selective and robust.

16
  • ICARO FERREIRA DE ABREU
  • Integration of nanosilicon in the structure of filamentous fungi: study and characterization of a new bio-hybrid material
  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • ARNAUD VICTOR DOS SANTOS
  • EDUARDO ARIEL PONZIO
  • MARCOS MALTA DOS SANTOS
  • REGINA MARIA GERIS DOS SANTOS
  • SORAIA TEIXEIRA BRANDAO
  • TIAGO FRANCA PAES
  • Data: 19 oct. 2018


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  • In the present thesis, we intend to present the work on the production of polycrystalline silicon from diatomite (SiO2) and its interaction with filamentous fungi. In addition, some results on silicon (Si) synthesis will be discussed using the magnesiothermic method, in which diatomite was used as precursor and metal magnesium as reducing agent. The polycrystalline silicon was obtained through the diatomite through the thermal process called magnesiothermic, using a temperature of 650 ° C for 7 hours. The processes were carried out in a single step, using silica-rich fossilized diatomaceous algae as the source of silicon. The silicon produced was subjected to HCl treatment and subsequent treatment with HF. The obtained silicon was used in the synthesis of a new bio-hybrid material, when integrated in the cell wall of filamentous fungi. Finally, the material was characterized using the techniques of Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, fluorescence spectroscopy and fluorescence microscopy. The main results are nanosilicon production with crystallite size of 1.5 nm, assimilation of this material by filamentous fungi and photoluminescent emission at 414 nm and 520 nm, giving a blue and red coloration, respectively.
     
     
17
  • NILTON DE ANDRADE ANTONINO

  • ZEOLITIZATION OF DIATOMITES AND ITS APPLICATIONS ON CO2 ADSORPTION AND CATALYTIC ESTERIFICATION OF GLYCEROL WITH ACETIC ACID

  • Leader : ARTUR JOSE SANTOS MASCARENHAS
  • MEMBRES DE LA BANQUE :
  • VALERIA CRISTINA FERNANDES
  • HELOYSA MARTINS CARVALHO ANDRADE
  • ARTUR JOSE SANTOS MASCARENHAS
  • ADRIANE VIANA DO ROSARIO
  • SUZANA MODESTO DE OLIVEIRA BRITO
  • RODRIGO DE PAULA
  • Data: 26 oct. 2018


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  •  

    Diatomites are amorphous sedimentes, originating from frustules or shells of unicellular
    plant organisms, such as microscopic aquatic, marine and lacustrine algae. The
    zeolitization process creates micropores and mesopores on the amorphous walls of
    the diatomite, transforming them into a material with hierarchically organized pores for
    applications, that can be used in separation, adsorption and/or heterogeneous
    catalysis. In this work three zeolitization methods were studied: i) Hydrothermal
    method using ethylenediamine as organic structure-directing agent; ii) hydrothermal
    method using tetrapropylammonium cation and iii) vapor transport method with
    tetrapropylammonium cation. The materials were characterized for their structural,
    morphological, textured and acidic properties. The zeolitized diatomites with
    ethylenediamine resulted in a mixture of phases composed of ZSM-5 and ferrierite.
    The increase in the hydrothermal treatment time results in more crystalline materials,
    with a lower Si / Al ratio in relation to the starting diatomite, better textural properties
    and higher density of acid sites. The materials partially retain their original
    morphologies, which are progressively destroyed as the zeolite phases increase. The
    materials obtained by the hydrothermal method using tetrapropylammonium cation
    resulted in the formation of mixtures of ZSM-5 and P zeolite phases. Increasing the
    hydrothermal treatment time results in a decrease in the ZSM-5 content and increase
    in the zeolite P content, affecting both the textural properties ant the acidity of the final
    material. The material with better textural properties is obtained in 3 days, but on the
    other hand the higher density of acid sites is obtained after 6 days of hydrothermal
    treatment. In addition, the initial morphology of the diatomites is compromised as the
    material is converted into a mixture of zeolitic phases. Materials prepared by the vapor
    transport method result in ZSM-5 zeolite as the sole crystalline phase, also retaining
    much of the initial morphology of the diatomites. However, the zeolitization process
    tends to be more superficial, resulting in textural and acidic properties lower than those
    observed for the materials produced using ethylenediamine or as the structure
    directing agent. All these hierarchical materials were investigated as acid catalysts in
    the esterification reaction of glycerol with acetic acid to produce acetines. The catalysts
    obtained by zeolitization with the ethylenediamine driver resulted in better conversions
    (> 90%) and high selectivities to both monoacetin and diacetins, reflecting the
    hierarchical nature of these catalysts. The other materials presented lower conversions
    and high selectivities only to monoacetin, suggesting that the catalytic behavior is
    being governed only by the zeolitic phases present.

18
  • DAVID FARIAS LOCKWOOD
  • Hidrocarbonetos policíclicos aromáticos no Recôncavo baiano: exposição ambiental e risco de câncer em humanos

  • Leader : VANIA PALMEIRA CAMPOS
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • VANIA PALMEIRA CAMPOS
  • FERNANDO MARTINS CARVALHO
  • MARCO ANTONIO VASCONCELOS REGO
  • SEVERINO SOARES AGRA FILHO
  • TANIA MASCARENHAS TAVARES
  • Data: 29 nov. 2018


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  • Polycyclic aromatic hydrocarbons (PAHs) are pollutants that are usually emitted by combustion processes. Petroleum-related and industrial activities are main sources of environmental emissions of PAHs via atmospheric emissions, liquid effluent, spills and solid waste. The main health concern is cancer. The goal of this study was to assess the incremental lifetime cancer risk due to PAH exposure from ambient airborne particulate matter, drinking water and edible mollusks at different locations of various cities with industrial activity in the Recôncavo Baiano and the Salvador metropolitan area: Caípe, Candeias, Ilha de Maré, Jabequara and Madre de Deus and São Francisco do Conde as industrial regions with petroleum operations; Baiacu and Saubara, areas downwind from industrial emissions, although relatively far; Salvador, an urban area; Arembepe and Praia do Forte as reference areas. The methodology used was a probabilistic assessment using the Monte Carlo method via the software Oracle Crystal Ball. The results of the simulations for a 70-year lifetime (95th percentile) showed a higher incremental lifetime cancer risk in Caípe with a risk of 1,3 x 10-3 , which corresponds to between one and two additional individuals with cancer in a population of 1,000, an unacceptably high risk; Ilha de Maré with a risk of 9,4 x 10-4 , São Francisco do Conde with a risk of 3,0 x 10-4 and Madre de Deus with a risk of 1,6 x10-4 , all values above the maximum acceptable. At these locations, the risk is associated to the consumption of mollusks from the local area. For the cities where mollusk data was not collected, Candeias had the highest incremental lifetime cancer risk, 5,2 x 10-5 , associated to the high concentration of PAHs in the airborne particulate matter. Acceptable incremental cancer risks were found in Jabequara (6,5 x 10- 6 ), Saubara (1,5 x 10-6 ) Baiacu (7,2 x 10-7 ), Salvador (4,9 x 10-7 ), Praia do Forte (2,3 x 10-6 ) and Arembepe (7,8 x 10-9 ). The estimates for incremental cancer risk associated to PAH exposure for the mollusk-consuming populations to the north and the northeast of the All Saints Bay call for the attention of health and environmental regulatory agencies. SUMÁRI

19
  • LEONARDO RIBEIRO TELES
  • Synthesis and characterization of dendrimer-encapsulated gold and platinum nanoparticles for integration into the structure of filamentous fungi
  • Leader : MARCOS MALTA DOS SANTOS
  • MEMBRES DE LA BANQUE :
  • MARCOS MALTA DOS SANTOS
  • ELISANGELA FABIANA BOFFO
  • TIAGO VINICIUS ALVES
  • REGINA MARIA GERIS DOS SANTOS
  • CESÁRIO FRANCISCO DAS VIRGENS
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • Data: 30 nov. 2018


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  • In this work, the development of bio-hybrids through gold and platinum nanoparticles encapsulated in generation 5 and 6 dendrimers having hydroxyl groups and amines at their ends was obtained in an unprecedented way. Filamentous fungi Phialomyces macrosporus and Trichoderma sp were used as biotemplates. The fungal growth occurred by means of two methods: a static form in media with dextrose and other mechanically stirred with potato extract and dextrose. After elaboration, the bio-hybrid Trichoderma sp / nanoparticles of platinum encapsulated by generation 5 dendrimer (Trichoderma sp/G5-Den(OH)-Pt40) was used as catalyst in the model reduction reaction of 4-nitrophenol (4-NF) to 4-aminophenol (4-AF). The catalytic activity was investigated in the presence of excess sodium borohydride (NaBH 4) by UV-Vis spectroscopy. The reaction showed a kinetic profile of pseudo-first order obtaining results consistent with that of the literature. In addition to the application in catalysis, microtubular structures were obtained from the gold and platinum species by means of controlled calcination (10 ºC / min) up to 600 ºC in ambient air. Analysis of UV-Vis spectroscopy and transmission electron microscopy revealed the formation of encapsulated metal nanoparticles in generation 5 and 6 dendrimers with sizes of around 3 nm and 7 nm, respectively. In addition to scanning electron microscopy (SEM) and transmission (TEM) analyzes, X-ray dispersive energy (EDS) microanalysis along with thermogravimetric analysis (TGA) and UV-Vis spectroscopy evidenced the production of bio- hybrids. Thus, the characteristics of the fungus biofilm / NP fungus make it possible to use both catalysis and precursors of microtubular structures that can be applied as microelectrodes.
     
     
20
  • LUCIANE BRITO DA PAIXÃO
  • STRATEGIES FOR THE DETERMINATION OF INORGANIC CONSTITUENTS IN CHOCOLATE AND COCOA DERIVATIVES BY SPECTROMETRIC TECHNIQUES
     
     
     
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • MARIA DAS GRACAS ANDRADE KORN
  • LEONARDO SENA GOMES TEIXEIRA
  • RAILDO MOTA DE JESUS
  • ANIBAL DE FREITAS SANTOS JUNIOR
  • Data: 14 déc. 2018


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  • The aim of this work was to develop analytical methods for determination essential and non essential elements in samples of chocolates and cocoa derivatives using atomic spectroscopy techniques. In the first step, a procedure for wet-assisted microwaveassisted decomposition of chocolate bars sample and subsequent determination by microwave-induced plasma optical emission spectrometry (MIP OES) was evaluated. The procedure was optimized using chemometric tools, and the optimal conditions obtained were: 4 mol L-1 of HNO3 with 1 mL of 30% m m-1 H2O2 and 190 ºC. The method was validated in terms of accuracy with recovery percentages in analyte addition tests ranging from 82.8 to 105% and for certified reference material (NIST SRM 2384) in the range of 94 to 113%. The method was applied in 15 chocolates bars samples, the concentration ranges obtained were, in mg kg-1: Ca (653 - 3.096); Cr (<0.62.85); Cu (<0.15 - 19.5); Fe (<1.65 - 227); Mg (147 - 2775); ); K (3554 – 8573); Mn (<0.042 - 25.2); Na (45.6-1095); Ni (3.2 - 10.2); P (1111 - 22594) and Zn (4.8-33.3). The samples of bitter chocolate have a higher concentration of essential and non essential elements when compared to white chocolate and milk, except for Ca and Na. Ten samples exceeded the limit established for Ni, and 5 samples of bitter chocolate exceeded the limit for Cr, according to ANVISA. In the second step, a method for the direct analysis of samples of chocolate, cocoa and powdered chocolate by energy dispersive X-ray fluorescence spectrometry (EDXRF) was investigated. The accuracy of the method was evaluated by comparing the results obtained with those of the reference method by inductively coupled plasma optical emission spectrometry (ICP OES), and no significant differences were observed between the two methods according to the single factor ANOVA. The concentration ranges obtained were, in mg kg-1: Al (13.3 - 136.5); Ca (160 - 11113); Cu (2.1 - 38.9); Fe (30 - 1070); Mg (405 - 3187); Mn (3.7 - 82.8); P (376 - 2820) and Zn (7.1 - 53.9). The cocoa powder presented higher concentration for most of the elements; and significant concentrations of aluminum have been found, which serves as an alert since excessive intake of aluminum is associated with health hazards.
     
     
21
  • DENILSON SANTOS COSTA
  • Study of catalysts based on Ni and Nb applied to catalytic partial oxidation of methane

  • Leader : SORAIA TEIXEIRA BRANDAO
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
  • MARIA DA GRACA MARTINS CARNEIRO DA ROCHA
  • ROGER THOMAS FRANCOIS FRETY
  • SORAIA TEIXEIRA BRANDAO
  • Data: 14 déc. 2018


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  • Ni and Nb-based catalysts obtained from LaNiO3, LaNi0,5Nb0,5O3 e NiO/Nb2O5, were tested on Catalytic Partial Oxidation of Methane (CPOM). TPR-H2 and XRD under reducing atmosphere indicated that after reduction, LaNiO3 is converted to Ni0/La2O3. Therefore, LaNi0,5Nb0,5O3 is reduced to Ni0/ La2O3-LaNbO4 and NiO/Nb2O5 into Ni0/Nb2O5 forms. Temperature Programmed Surface Reaction indicated that only those catalysts obtained from LaNiO3 and LaNi0,5Nb0,5O3 presented activity on CPOM under the experimental conditions. XRD under reaction atmosphere indicated that LaNi0,5Nb0,5O3 was more resistant towards Nisites oxidation, an important feature since NiO sites are known to be active on CH4 total oxidation. Long-term catalytic tests (18,5h) showed that the Nb-containing catalyst synthesized from a perovskite precursor exhibited the highest catalytic activity, which could be related to a higher Ni available surface and in agreement with the Ni particles average diameter measurements. This catalyst has shown a H2/CO ratio comparable to the one obtained on CPOM, indicating the insignificant effect of side reactions. Once regenerated, the catalysts obtained from LaNiO3 e LaNi0,5Nb0,5O3 precursors presented higher catalytic activity.
     
     
22
  • JACQUELINE PEIXOTO MIRANDA BADARÓ
  • TRIHALOMETHANES IN RESIDENTIAL TANKS FOR WATER STORAGE TREATED. TRAINING IN LOCO VERSUS EXTERNAL TRANSFER
     
  • Leader : VANIA PALMEIRA CAMPOS
  • MEMBRES DE LA BANQUE :
  • LUCIANO MATOS QUEIROZ
  • MADSON DE GODOI PEREIRA
  • MARCOS DE ALMEIDA BEZERRA
  • PEDRO AFONSO DE PAULA PEREIRA
  • VANIA PALMEIRA CAMPOS
  • Data: 19 déc. 2018


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  • In the disinfection of water for human consumption with chlorine and other compounds secondary reactions occur with the organic matter, generating undesirable disinfection by-products (DBPs). Among these are trihalomethanes (THM), the most common being CHCl3, chloroform or trichloromethane, TCM; CHCl2Br, bromodichloromethane, BDCM; CHBr2Cl, dibromochloromethane, DBCM; and CHBr3, bromoform or tribromomethane, TBM. This work determined speciated and total trihalomethanes in treated water and stored in tanks of residential condominiums of different social classes. The determination was made by gas chromatography with electronic capture detector, using Headspace as preconcentration technique. The average percentage distribution of the speciated THMs was the same for the water stored in the tanks or distributed: CHCl3> CHCl2Br> CHClBr2> CHBr3. In all the condominiums considered in this study, regardless of social class, the water that arrived for the supply already contained THMs. Individual results show that the concentration of speciated THM and TTHM was in many cases higher in the distributed water than in stored water. 80% of the measurements presented TTHMs exceeding the legislated value in Brazil (100 μg L-1) and in relation to the speciated THMs, their levels exceed the recommended international limits, mainly referring to TCM and BDCM, that are among the most toxic. The reduction of TTHM concentration in the stored water after tank cleaning was estimated in 96%, while the increase was 92% after a year and a half without cleaning, emphasizing the importance of this procedure periodically. The multivariate analysis of the datasets obtained using HCA and PCA techniques showed that the formation of THMs in the speciated and total forms is influenced by Temperature, conductivity and different forms of chlorine and that, in general, there is no significant distinction between the water distributed and stored in tanks, that is, the main formation of THMs in the water consumed by the population does not occur in the residential storage tanks.

23
  • Pamela Dias Rodrigues
  • Study of the feasibility of using surfactant solution produced from soapstock (refining sludge), refining co-product of vegetable oils, as an advanced oil recovery fluid and its interactions in the reservoir
  • Leader : CRISTINA MARIA ASSIS LOPES TAVARES DA MATA HERMIDA QUINTELLA
  • MEMBRES DE LA BANQUE :
  • CRISTINA MARIA ASSIS LOPES TAVARES DA MATA HERMIDA QUINTELLA
  • RAILDO ALVES FIUZA JUNIOR
  • ELIAS RAMOS DE SOUZA
  • HUMBERVÂNIA REIS GONÇALVES DA SILVA
  • MARILENA MEIRA
  • Data: 20 déc. 2018


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  • The need to introduce renewable and clean fuels is undeniable. However, there is still a strong dependence on fossil fuels. The present work meets the criteria of science, technology and innovation in both cases, as it proposes the use of a surfactant solution produced from the saponification reaction of the soapstock, a co-product of the refining production of biodiesel oils, as a recovery fluid oil, adding value to one of the byproducts of biodiesel production and proposing an efficient and inexpensive method for oil extraction, especially in mature fields. Six displacement tests were carried out in the Holder system, which showed that the use of the soapstock surfactant solution improved the mobility of the oil, leading to an increase in the sweeping and displacement efficiency, with supplementary recovery factors being reached in the conventional phase between 10 and 15% . This factor is superior to that found in similar commercial surfactant injection tests (4-7%). This behavior may be directly related to the ability of the surfactant solution to significantly reduce the oil / water interfacial tension to 0.8mN.m-2. The interaction between the produced surfactant solution and the reservoir fluids was studied by Tensiometry, Fourier Transform Infrared Region (FTIR),Spectrofluorimetry and LED Induced Fluorescence Spectroscopy (FIL). From the analyzes of LED Induced Fluorescence Spectrofluorimetry it was verified that the surfactant solution produced mainly recovered the petroleum fractions of smaller HPAs. However, the use of the surfactant solution did not significantly alter the chemical properties of the oil. Therefore, this work proved that the use as an injection fluid of the surfactant solution produced in the saponification reaction of the soapstock is an extremely promising chemical recovery method especially in mature fields of the Recôncavo Baiano, since this solution can be produced with low cost and through a simple and robust method, and can be applied easily in the field.
     
     
2017
Thèses
1
  • LAILA CONCEICAO DOS SANTOS
  • PREPARATION OF ANODIC CATALYSTS FOR THE BIOGAS REFORM
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • CARLOS AUGUSTO DE MORAES PIRES
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • MARLUCE OLIVEIRA DA GUARDA SOUZA
  • RAILDO ALVES FIUZA JUNIOR
  • SORAIA TEIXEIRA BRANDAO
  • ZENIS NOVAIS DA ROCHA
  • Data: 23 nov. 2017


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  • Solid Oxide Fuel Cells (SOFCs) are one of the most promising energy conversion devices due to the flexibility of fuel, operation temperature, high efficiency and tolerance to contaminants, besides the high amount of heat generation, facilitating cogeneration. An economical and practical way to operate these devices is to generate hydrogen on board, by reforming hydrocarbons, for example biogas. In addition, there is a commitment to the development of solid oxide fuel cells that can operate at low temperatures to reduce manufacturing and operating costs. However, the most commonly used Ni-YSZ catalyst loses efficiency by decreasing the operation temperature of the cell, ceramic materials based on cerium oxide being proposed as promising anode materials to achieve a better overall cell performance. In order to obtain more efficient catalysts in the dry reforming of biogas, the effect of rhodium and samarium was studied on the properties of ceria-supported nickel catalysts. Monometallic supported nickel (30%) and bimetallic nickel (30%) and rhodium (0.1, 0.5 and 1%) catalysts were prepared using pure ceria and samariumdoped ceria (10 mol%) as supports. Samples were prepared by precipitation methods, followed by impregnation of the metals. The solids were characterized by Fourier transform infrared spectroscopy, thermogravimetry, differential thermal analysis, X-ray diffraction, specific surface area and porosity measurements, temperature programmed reduction, Raman spectroscopy, ultraviolet-visible spectroscopy and differential pulse voltammetry. It was observed that samarium was incorporated in ceria lattice and it addition caused the expansion of the unit cell volume of a fluorite-like structure, decreased the average crystal size, increased the specific surface area and the pore volume, acting as a textural promoter. In addition, samarium facilitated ceria reduction, besides increasing the metal interaction with the support and creating spatial defects related to oxygen in ceria lattice without changing the electronic properties of ceria. The redox processes are centered on the cerium and nickel atoms and modification on the cathodic and anodic currents after the impregnation of the rhodium. The most promising catalysts were those supported on samarium-doped ceria.

2
  • Darlan Carneiro Balesteiro da Cruz
  • GLYCEROL OXIDEHIDRATATION AT ACRYLIC ACID OVER ZEOLYTICS CATALYSTS WITH TIN AND ANTIMONY.

  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • ARTUR JOSE SANTOS MASCARENHAS
  • HELOYSA MARTINS CARVALHO ANDRADE
  • TEREZA SIMONNE MASCARENHAS SANTOS
  • Data: 15 déc. 2017


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  • The production of biodiesel is one of the great technological advances of the Country. Following a growing trend, it is expected an increase in the amount of glycerin inserted in the national market, generated as a co-product of the transesterification reaction. Glycerol is a molecule with a wide variety of applications, but its commercial use is tied to the need for purification to remove toxic compounds. Oxidative dehydration over bifunctional catalyst, which performs the acid and redox function, is a promising, economically viable and sustainable alternative of conversion of glycerol to acrolein and acrylic acid. Acrylic acid appears as the main application in superabsorbent polymers (SAP) and acrylates. In this work, catalysts formed by zeolite ZSM-5 and mixed oxides of tin and / or antimony were synthesized by the methods of wet impregnation and/or physical mixture for later evaluation of the catalytic performance in the oxidative dehydration of glycerol to acrylic acid in gas phase. The catalysts were characterized by TG/DTG, FTIR, EDX, TPR, TPD-NH3, DRX, MEV, EDS, textural analysis and UV-Vis DRS. The ZSM-5 zeolite was obtained with SiO2/Al2O3 = 22 experimental MFI topology. The synthesis of bimetallic tin and antimonium catalysts supported on ZSM-5 resulted in materials with equimolar Sn:Sb ratios. The order of addition of the metals to the support and the incorporation method did not significantly influence the final composition value of the catalysts. The presence of the metals promoted the reduction of the total density of ZSM-5 acid sites, but increased the density of strong acid sites. H-ZSM-5 showed approximately 80% conversion of glycerol and 75% selectivity to acrolein in the first hours of reaction, but the conversion was reduced to 29%, while the selectivity to acrolein remained high until the tenth hour of reaction. Sb acted to prevent coke, while Sn favored conversion. The catalysts are active to acrylic acid only when tin and antimony act simultaneously. The formation of acrylic acid was favored when a higher concentration of antimony was obtained in relation to the tin and that they occurred preferentially in the external surface of the catalyst, where these conditions were obtained. Acrylic acid with selectivity of 47.4% in the tenth hour of reaction for the bimetallic tin and antimony catalyst supported in ZSM-5 synthesized by the physical mixing method.

     
Thèses
1
  • ISA DOS SANTOS BARBOSA
  • Evaluation of the distribution of metals and metalloids in surface marine sediments collected in the Bay of Aratu, 
    Bahia, Brazil
  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • AMALIA GEIZA GAMA PESSOA
  • ELISANGELA DE ANDRADE PASSOS
  • MADSON DE GODOI PEREIRA
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • SERGIO LUIS COSTA FERREIRA
  • Data: 4 août 2017


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  • The objective of this work was to evaluate the distribution of metals and metalloids in samples of superficial marine sediments collected in the Bay of Aratu, Bahia, Brazil. Samples were collected at ten points in three campaigns (March, June and September 2014). The Environmental Protection Agency procedure, EPA 3051A was applied for sediments parcial decomposition. The samples were analyzed for determination of As, Co, Cu, Cr, Fe, Li, Mn, Ni, Pb, Se, V and Zn by inductively coupled plasma optical emission spectrometry (ICP OES). The elements Be, Sc and Y were used as internal standard candidates. The results showed that use of internal standardization depends on specific study for each analyte, considering that an optimum condition that met all the elements for analysis of marine sediments by ICP OES was not found. The procedure was validated from the analytical parameters: precision, accuracy, LOD and LOQ. To evaluate the accuracy, the CRM 2702 (marine sediment with inorganic constituents) was used.The results obtained after application of the microwave-assisted acid extraction procedure and determination for ICP OES were evaluated through guideline values established by the sediment quality guides (SQG). It was possible to infer that the samples collected in the Bay of Aratu, which presented concentrations of the elements above the minimum values, may probably lead to adverse effects on the biota, mainly for As, Cu and Ni. This work is a pioneer in the accomplishment of a preliminary analysis on construction of a regional geochemical base in Aratu bay. In addition, the enrichment factor (EF) and geoacumulation index contributed to the classification in relation for level of contamination of the area, presenting similar results in relation for possible anthropic enrichment of As, Co, Cr Cu Mn and Zn elements. Finally, the ultrasonic-assisted acid extraction procedure was optimized. The extraction using 1.0 mol L-1 HCl using ultrasonic bath and glass tube was validated and sediment samples were applied. The analytes that showed lower concentrations after chemical extraction were Cr (1.78 - 5.52 μg g -1) and Ni (2.07 - 6.31 μg g -1). The highest bioavailable concentrations were obtained for Cu (16.8 - 43.3 μg g -1), Zn (16.6 - 44.6 μg g -1) and Mn (373 - 842 μg g -1). In addition, the ultrasound-assisted extraction procedure presented statistically similar percentages to those obtained after extraction using a stirring table, guaranteeing a reduction in sample preparation time. The work accomplished can alert the need for constant monitoring in the region, in order to generate a database that contribute to effective actions of environmental control and decontamination.

2
  • MILENA SANTOS PINELLI
  • Strategies for determination of inorganic species in lubricating oils of automotive vehicles by spectrometric techniques

  • Leader : MARIA DAS GRACAS ANDRADE KORN
  • MEMBRES DE LA BANQUE :
  • CLÉSIA CRISTINA NASCENTES
  • DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
  • LEONARDO SENA GOMES TEIXEIRA
  • LILIAN LEFOL NANI GUARIEIRO
  • MARIA DAS GRACAS ANDRADE KORN
  • RENNAN GEOVANNY OLIVEIRA ARAUJO
  • Data: 16 août 2017


  • Afficher le Résumé
  • The main functions of automotive lubricating oils range from the reduction of friction and wear caused by moving parts of the motor vehicle, to corrosion and rust protection, also contributing to the cooling and cleaning of the motor. However, these oils partially deteriorate in the presence of metals from the wear of engine parts and form compounds that can compromise the good operation of the vehicle. Thus, the present work proposes analytical strategies to evaluate the inorganic species present in lubricating oils before and after use in automotive vehicles. A method of sample preparation from microwave-assisted cavity decomposition was evaluated, using nitric acid, 65% HNO3 m m-1, with residual acidity of 2.7 mol L-1 and hydrogen peroxide, H2O2 30% v v-1, with maximum temperature and time of 220 ° C and 30 min, respectively. The determinations of the analytes were done by inductively coupled plasma optical emission spectrometry (ICP OES), inductively coupled plasma mass spectrometry (ICP-MS) and dispersive energy X-ray fluorescence (EDXRF). The three methods for determination of Al, As, Ca, Fe, Mg, Mo, P, S, Si, Sn, Sr and Zn by ICP OES, Ba, Cd, Co, Cr, Cu, Mn, Ni, Ti and V by ICP-MS and an alternative method with samples dripped on quantitative filter paper for determination of As, Ca, Mo, S, Si, Sr and Zn by EDXRF were validated with percentages of recovery in addition tests of analytes in the DJL 2U and (NIST SRM 1848) samples of lubricating oil, ranging from 81 to 107% for most elements determined by ICP OES and EDXRF and a range of 70 to 115% for quantification by ICP-MS. Besides, a method of direct determination of Ca, Cr, Cu, Fe, Mn, Mo, Ni, Pb, S and Zn by EDXRF in the samples of new and used lubricating oils were investigated, with LOD values obtained (mg kg- 1) ranging from 0.5 (Zn) to 4.5 (Ca) and percentages of agreement for Ca, P, S and Zn, in NIST SRM 1848  of lubricating oil and SRM 1624d diesel oil, ranging from 95 to 114%. The method of direct analyze of the proposed sample were applied in the determination of these elements in 28 samples of new and used lubricants in automotive vehicles. The concentration ranges obtained were, in mg kg-1: Ca (1,524 - 4,127); Cr (1.3 - 3.0); Cu (1.9 - 6.7); Fe (0.5 - 62.5); Mn (1.2 - 2.5); Mo (4.5 - 195); Ni (0.4 - 1.4); S (2,130 - 10,322) and Zn (849 - 1,275). The significant concentrations for Cu, Fe, and Ni found in the waste oils samples evaluated can indicate a warning signal for wear on engine parts in vehicles and the necessary for efficient quality control.

2016
Thèses
1
  • WYLLIAN FRANZ DOS SANTOS OLIVEIRA
  • DEVELOPMENT OF A METHOD FOR EXTRACTION OF VOCs EXHAUSTED FROM THE HAIR OF DOGS INFECTED WITH Leishmania sp. THROUGH THE TD-GC-FID TECHNIQUE
  • Leader : SILVIO DO DESTERRO CUNHA
  • MEMBRES DE LA BANQUE :
  • FREDERICO DE MEDEIROS RODRIGUES
  • JAILSON BITTENCOURT DE ANDRADE
  • VANIA PALMEIRA CAMPOS
  • Data: 12 août 2016


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  • Visceral leishmaniasis is a major public health problem, affecting thousands of people around the world every year, especially in developing countries such as Brazil. Dog is a principal host of the disease, because of its proximity to human beings and the ease to acquire and develop high parasite loads. Recent studies suggest that the infected dog with L. infantum produces physiopathological responses that changes, among other things, the profile of volatile metabolites exhaled from the animal hair and that there is a preferred demand from vector to infected dogs. The present work develops a method to extract volatiles exhaled from canine hair by TD-GC-FID technique, in order to enable studies to better understand the role of these VOCs in vector-host attraction. In order to carry out this work, samples were classified into three groups: infected dogs and with high parasite load; infected dogs, but with low parasite load and healthy dogs, but without the presence of parasite. The method developed includes solid phase extraction and sampling by purge and trap. All the factors that affect in the VOCs canine hair sampling were evaluated by multivariate designs. The huge amount of data generated by 105 samples were classified into three groups studied by Partial Least Squares Discriminant Analysis (PLS-DA). The misclassification of samples were mitigated by removing of uninformative VOCs, using techniques such as Multiple Linear Regressions Genetic Algorithm (MLR-GA-DA) and Stepwise Multiple Linear Regression (Stepwise MLR-DA). The number of samples misclassified were significantly reduced, providing a satisfactory model for classification of those three groups. Changes in the regression coefficients of the MLR-GA-DA/Stepwise MLR-DA in the selected VOCs indicate the 1-hexanol, 1-octanol and nonadecane as potential biomarkers of canine visceral leishmaniasis. A method for extraction of VOCs using TD-GC-FID, which enables to obtain an extract from canine hair volatiles and allow us to investigate the vector-host attraction was developed and used to discriminate the three sample classes.

2
  • Diego da Silva Vasconcellos
  • HPLC-UV URINARY CUTIN DETERMINATION FOR EVALUATION OF ASMATIC PATIENTS EXPOSURE TO SMOKING

  • Leader : LEONARDO SENA GOMES TEIXEIRA
  • MEMBRES DE LA BANQUE :
  • LEONARDO SENA GOMES TEIXEIRA
  • RODOLFO DE MELO MAGALHAES SANTANA
  • SERGIO TELLES DE OLIVA
  • TANIA MASCARENHAS TAVARES
  • Data: 13 déc. 2016


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  • Although cigarette smoking is very old, concern about the harm caused by cigarette smoking is recent and has been reported in the literature for the first time in the 1970s. Cigarette smoke is a complex mixture of particulate matter and gas , In which more than 4000 substances have already been identified, and at least 50 of them have some carcinogenic potential. The nicotine present in the highest concentration in this smoke is the alkaloid responsible for the dependence. Smoking directly affects diseases of the respiratory tract, mainly individuals presenting with asthma, because besides aggravating the symptoms, it has a negative effect on the treatment. In this sense, the evaluation of the degree of exposure is necessary to estimate how this factor is influencing the treatment response of the asthmatic. Therefore, it is essential to biomonitor the individual to exposure to cigarette smoke, by determining the most stable nicotine metabolite and higher concentration, cotinine, eliminated by urine. The aim of this study was to determine the exposure levels of patients from the Nucleus Excellence of Asthma (NEA) by quantifying cotinine in urine. 1317 samples from patients with different degrees of asthmatic disease (control group, mild asthma and severe asthma) were analyzed. Cotinine levels were determined through the implantation and validation of a method already described in the literature that combines the use of an internal standard (IS), 2-phenylimidazole, extraction of IS and cotinine present in the urine with dichloromethane and determination by High pressure liquid chromatography (HPLC) with UV detection ( = 260 nm). The validation consisted of the evaluation of some parameters described by ANVISA resolution n ° 899 of May 29, 2003: linearity, selectivity, precision (intermediate and repeatability), accuracy, limits of detection and quantification. The method in question showed a good linearity in the working range (0-1500 μg.L-1), was selective to the analyte in question, besides presenting percentages of relative standard deviation (RSD) acceptable for the parameters intermediate precision and Repeatability (8.4 and 6.4%, respectively, for a cotinine urine standard of 100 μg.L-1). Accuracy was assessed by the percentage recovery of a standard of 500 μg.L-1 cotinine in urine, being found a value of 103.4%. The limits of detection and quantification were 6.46 and 19.59 μg.L-1, respectively. In general, NEA patients had low rates of exposure to cigarette smoke. About 86% of these had urinary cotinine concentrations below the limit of detection. In the comparison between the responses obtained by applying a standard questionnaire and the levels of cotinine that characterized the patient as an active smoker in the control, mild asthma and severe asthma patients, a contradiction percentage of 1.42, 0.73 and 6.0% respectively. This fact indicates that some patients with severe asthma omit their smoking status for fear of not being accepted into the program.

2012
Thèses
1
  • Viviane Gondim Lima
  •  

     
     
  • Leader : ANDRE ALEXANDRE VIEIRA
  • MEMBRES DE LA BANQUE :
  • MAGDA BERETTA
  • PEDRO AFONSO DE PAULA PEREIRA
  • VANIA PALMEIRA CAMPOS
  • Data: 30 mars 2012


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  •  

     
     
2010
Thèses
1
  • Ana Paula de Melo Monteiro Modesto
  • PREPARATION OF ZIRCONARY AND ZERIAL OXIDE CATALYSTS FOR DEHYDROGENATION OF ETHAN WITH CARBON DIOXIDE
  • Leader : MARIA DO CARMO RANGEL SANTOS VARELA
  • MEMBRES DE LA BANQUE :
  • GENEBALDO SALES NUNES
  • LILIANE MAGALHÃES NUNES
  • MADSON DE GODOI PEREIRA
  • MARIA DO CARMO RANGEL SANTOS VARELA
  • MICHELE OBERSON DE SOUZA
  • Data: 29 mars 2010


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  • The several applications of ethene in industry, mainly in the production of plastics, are increasing fast. However, the current production capacity of ethene is not enough to supply the market and then new processes and routes of producing ethene are required. Among them, the ethane dehydrogenation with carbon dioxide has been recognized as a promising route, since it can reuse the carbon dioxide produced by other processes of the same industry, avoiding the emission to atmosphere. However, the commercial viability of ethane dehydrogenation with carbon dioxide depends on the development of a solid with high activity. An attractive option is a catalyst based on zirconium and cerium oxides, which show suitable properties to be use as catalyst. The materials are prepared in tetragonal phase and show the oxi-redox properties and the high thermal stability suitable to catalyst. However, these properties largely depend on the preparation method. A promising route to get catalysts with suitable properties is the freeze-dried method which can assure the homogeneity and stoichiometry of the mixed oxide. In order to find alternative catalysts for ethane dehydrogenation with carbon dioxide, the preparation of zirconium and cerium mixed oxides by the freeze-dried method was described in this work. Zirconium-based samples with 10, 20, 30, 40, 50, 60 and 80% mol of cerium, as well as zirconia and ceria, were obtained from zirconium and cerium acetate and calcined at 500 and 700 ºC. The samples were characterized by Fourier transformed infrared spectroscopy, thermogravimetry, differential thermal analysis, X-ray diffraction, specific surface area measurements, temperature programmed reduction, Fourier transform Raman spectroscopy and temperature programmed desorption of carbon dioxide. The catalysts were evaluated in ethane dehydrogenation with carbon dioxide in the range from 450 to 740 ºC. The formation of cubic phase was observed for pure ceria and the tetragonal and monoclinic phases were detected for pure zirconia. The addition of cerium to zirconia stabilized the tetragonal phase for all solids, due to the formation of solid solutions. The addition of small amounts of the cerium to zirconia did not significantly change the specific surface area. On the other hand, for the samples calcined at 500 ºC, the addition to cerium (above 50% mol) produced an increase in the specific surface area of zirconia, associated to the textural action of cerium as spacer among the zirconia particles or to the generation of stresses in the solid, causing the equilibrium shift to the formation of smaller particles. The cerium reduction was dependent on the interaction with the zirconium. All catalysts presented mostly strong basic sites and were active in ethane dehydrogenation with carbon dioxide, the conversion increasing with temperature. Among the catalysts obtained, the sample with 40 % mol of cerium and calcined at 500 ºC, as well as the solid with 80 % mol of cerium mol and calcined at 700 ºC, led to the highest conversions. Therefore, the most promising mixed oxide-based catalysts were those with the highest amounts of cerium.

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