Chemistry Journal of Moldova

STOPPED-FLOW SPECTROPHOTOMETRIC STUDIES OF THE KINETICS OF INTERACTION OF DIHYDROXYFUMARIC ACID WITH THE DPPH FREE RADICAL

Author(s):

Secara Natalia


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2010 Volume 5, no.2
Pages: 83-87
Keywords:

DPPH; antioxidant activity; stoichiometry; stopped-flow; kinetics; dihydroxyfumaric acid.


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DOI:
dx.doi.org/10.19261/cjm.2010.05(2).11

Graphical Abstract:
 The reaction of dihydroxyfumaric acid with the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied using the stopped-flow method, in order to describe the reaction kinetics. Dihydroxyfumaric acid reacts very rapidly with DPPH, the reaction being completed in several minutes. This 2-stoichiometric reaction proceeds in two stages, with reaction orders of 1 and 0.76 with respect to DPPH, and 0.5 and 0.3 with respect to DHF, respectively. The rate constant of the two stages of the reaction were found to be 39.1 (L/mol•s) and 0.0012 (s-1) at 20º C and pH 4.0.


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