Kinetics of oxidative degradation of DL-methionine by cerium(IV) in aqueous perchloric acid media

Abstract

The kinetics of oxidation of DL-methionine by cerium(IV) in aqueous perchloric acid solution have been studied spectrophotometrically. The reaction shows first order kinetics in [Ce I V ] and an apparent less than unit order dependence each in [DL-methionine] and [acid]. The data suggest that the oxidation proceeds via the formation of a complex between methionine and cerium(IV) which decomposes in a slow step to give a free radical which on reacting with one more molecule of cerium(IV) in a fast step gives the products. The reaction constants involved in the mechanism are evaluated.