Oxygen electrode as a new tool to evaluate hydroxyl radical-scavenging ability

An oxygen electrode was applied to determine hydroxyl radical (OH) levels for the first time. The method is based on the determination of OH generated by the Fenton reaction using the reaction of OH with a scavenger and the resulting radical consuming an oxygen molecule stoichiometrically. Thus, the OH-scavenging abilities of antioxidant reagents, as well as the concentration of OH, can be determined by the measurement of consumption of dissolved oxygen using an oxygen electrode. A good correlation between the present method and conventional colorimetry was obtained for the estimation of the OH-scavenging activities of antioxidants. Furthermore, the results correlated with the OH-scavenging rate constants of the reagents evaluated by a “cupric ion reducing antioxidant capacity (CUPRAC)” assay. We applied the present method to estimate the OH-scavenging abilities of commercially available alcoholic drinks.