Electrochemical Determination of the Antioxidant Capacity of Organic Compounds

Abstract

This work analyzes different proposals concerning the importance of organic compounds to determine their antioxidant capacity per equivalent, among which that of ({plus minus})-6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid, trolox, is considered because it is based on a stable radical reaction 2,2-Diphenyl-1-picryl-hidrazyl, DPPH, with trolox; the decrease of the DPPH signal given by trolox is compared to that of trolox with the species of interest. The study was carried out electrochemically and spectrophotometrically, although it was also determined using biosensors with tyrosinase, which analyzes the response of the biosensor in the presence of catechol to determine thus the antioxidant capacity referred to catechol equivalents, monitoring the substrate's amperometric signal. The reaction was analyzed with the Folin-Ciocalteu reagent to determine total phenol compounds, comparing with the results from the methods used.