Banca de DEFESA: ROSANA CELESTINO DE JESUS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ROSANA CELESTINO DE JESUS
DATE: 25/03/2022
TIME: 09:00
LOCAL: Sala de Seminários e Defesas da Pós-Graduação em Química da UFBA
TITLE:

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

KEY WORDS:

Paprika, Minerals, Sample preparation, ICP OES

PAGES: 102
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SPECIALTY: Métodos Óticos de Análise
SUMMARY:

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.

BANKING MEMBERS:
Interna - 2721446 - DANIELE CRISTINA MUNIZ BATISTA DOS SANTOS
Interno - 3204824 - JOAO BATISTA PEREIRA JUNIOR
Interno - 1698441 - RENNAN GEOVANNY OLIVEIRA ARAUJO
Externa à Instituição - JACIRA TEIXEIRA CASTRO
Externa à Instituição - LUANA NOVAES SANTOS - UESC