Mechanism of electrochemical interaction between sulfur-containing amino acids and anodically polarized platinum electrode

Electrooxidation of cysteine and methionine on a platinum electrode in solu tions with various pH values is studied by the RDE and linear-sweep voltamm etry methods. Based on this study and previous adsorption measurements, kin etic equations and mechanisms of main processes, which occur on the anodica lly polarized platinum electrode in the presence of the amino acids and lea d to electrocatalytic dissolution of platinum, are proposed. Anodic dissolu tion of platinum in the presence of cysteine and methionine is accelerated due to immediate involvement of the sulfur atom in the adsorption and elect rooxidation on the platinum electrode surface.