Banca de DEFESA: REGIANI MARIA LEOPOLDINA MARTINS SANDRINI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : REGIANI MARIA LEOPOLDINA MARTINS SANDRINI
DATA : 22/09/2021
HORA: 09:30
LOCAL: Santo Andre - Sala Virtual - Google Meets (https://meet.google.com/mdt-ikcw-piq)
TÍTULO:

EXPERIMENTAL OPTIMIZATION APPLIED TO THE ELECTROCHEMICAL STUDY OF GALlIC ACID OXIDATION REACTION ON GOLD ELECTRODES

PÁGINAS: 155
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Físico-Química
ESPECIALIDADE: Eletroquímica
RESUMO:

Phenolic compounds have high antioxidant power, due to the presence of compounds such as gallic acid and are present in several red fruits, especially pomegranate. The electrochemical behavior of GA was investigated by applying the techniques cyclic voltammetry and square wave voltammetry under an Au electrode. Gallic acid electro-oxidation reaction involves the transfer of two electrons and two protons, characterized by two steps, being the formation of the irreversible semiquinone and the reversible quinone. Experimental optimization was applied to SWV, response surface methodology and a 23 factorial design were used to evaluate the effects of the three independent variables considered for the optimization of the oxidative process: frequency, potential increment and amplitude. In the optimization, the correlation coefficient for the model was 0,9830 and the optimal conditions established at f=180 Hz,∆E_s=5 mV e a=25,5 mV. The electroanalytical methodology for the determination of the antioxidant activity of fresh pomegranate samples and food supplements was developed and validated. The method presented linearity in the range of 10-100 μmolL-1 with LOD=4,87 e LOQ=16,22 μmolL-1. Under ideal conditions, the antioxidant activity of the pomegranate and GA samples were evaluated by the electrochemical index (EI) being determined the values of 213.25 ; 193.56  e 155.24 μAV^-1  and 0.84 3,0 ;  1,09 e 0,84 μmol/ g sample sample, respectively, for standard GA, fresh pomegranate and food supplements.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1654772 - CAMILO ANDREA ANGELUCCI
Membro Titular - Examinador(a) Interno ao Programa - 1544379 - ANDERSON ORZARI RIBEIRO
Membro Titular - Examinador(a) Externo ao Programa - 1909336 - ALEXANDRE ZATKOVSKIS CARVALHO
Membro Titular - Examinador(a) Externo à Instituição - MARCOS AURÉLIO ALMEIDA PEREIRA - UNIP
Membro Titular - Examinador(a) Externo à Instituição - VINICIUS DEL COLLE - UFAL
Membro Suplente - Examinador(a) Interno ao Programa - 1543683 - IVANISE GAUBEUR
Membro Suplente - Examinador(a) Externo à Instituição - PATRICIA VASCONCELOS BARBOSA SANTIAGO - UNICAMP
Membro Suplente - Examinador(a) Externo à Instituição - FLÁVIO COLMATI JÚNIOR - UFG