Banca de DEFESA: LEANE SANTOS NUNES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LEANE SANTOS NUNES
DATA : 17/05/2019
HORA: 08:30
LOCAL: Sala de seminários
TÍTULO:

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

PALAVRAS-CHAVES:

manganese; vanadium; SDME; ionic liquids; GF AAS; ImageJ

PÁGINAS: 137
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Analítica
ESPECIALIDADE: Análise de Traços e Química Ambiental
RESUMO:

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).

MEMBROS DA BANCA:
Presidente - 282814 - MARIA DAS GRACAS ANDRADE KORN
Interno - 1190574 - RODOLFO DE MELO MAGALHAES SANTANA
Interno - 670.936.635-91 - VALFREDO AZEVEDO LEMOS - UFBA
Interno - 318.201.155-34 - WALTER NEI LOPES DOS SANTOS - UFBA
Externo à Instituição - CLEBER GALVAO NOVAES - UESB
Externo à Instituição - LUCIANA BAGDEVE DE OLIVEIRA DOS SANTOS - UEFS
Externo à Instituição - ANIBAL DE FREITAS SANTOS JUNIOR - UNEB