کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
193185 | 459764 | 2009 | 6 صفحه PDF | دانلود رایگان |
Interactions of five antioxidants (AO), quercetin (Q), morin (M), rutin (R), ascorbic acid (AA) and β-carotene (β-C) with anion radical and dianion of 1,3-dinitrobenzene (1,3-DNB) in two aprotic solvents – dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) – have been studied by cyclic voltammetry using glassy carbon electrode. Electrochemical parameters – peak potential (Ep), half-wave potential (E1/2), and peak current (ip) – for the reduction of 1,3-DNB before and after the addition of various concentrations of antioxidants, were evaluated. A gradual decrease in the oxidation peak current and finally irreversibility in 1,3-DNB radical anion and dianion systems upon the addition of antioxidant, reveals their interactions. The homogeneous bi-molecular rate constant (k2) was determined from electrochemical data. In comparison to all other antioxidants used, enhanced homogeneous second order rate constant for the interaction of morin with 1,3-DNB anion radical and dianion, was observed. This aspect is attributable to protonation initiated by hydrogen bonding and greater acidic nature of morin.
Journal: Electrochimica Acta - Volume 54, Issue 26, 1 November 2009, Pages 6184–6189