Studies on the autocatalyzed oxidation of amino acids by peroxomonosulfate

Abstract The kinetics of oxidation of six α‐amino acids (AA) by peroxomonosulfate (PMS) ion at pH 4.2 and 35°C are investigated once again. The rate of disappearance of peroxomonosulfate at constant [AA] and [H+] follows the equation equation image The experimental results suggest that the hydroperoxide intermediate formed by the reaction between the hydrated form of aldehyde and PMS is more reactive and is responsible for the autocatalysis. The hydroperoxide reacts with the amino acid in the rate‐determining step. This observation is contrary to the earlier explanation that the autocatalysis is due to the Schiff's base from amino acid and aldehyde. The effect of H+, the structure of the aldehyde, etc. on the rate constants are discussed. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 475–483, 2003