Electrochemical characterisation of uric acid and ascorbic acid at a platinum electrode

Cyclic voltammetric measurements at the rotating disk electrode have been carried out to investigate the electrochemical oxidation of uric acid, ascorbic acid and the simultaneous oxidation of both substances at a polycrystalline platinum electrode. The standard heterogeneous rate constant and the charge transfer coefficient have been determined for ascorbic acid to be 2.7 x 10(-4) m s(-1) and 0.15, respectively. It has been found that uric acid strongly adsorbs at the platinum electrode, and the diffusion coefficients for both compounds have been determined. Uric and ascorbic acid were found to undergo oxidation simultaneously in the same potential region. Our preliminary investigation of the mechanistic interactions will be discussed. (C) 2001 Elsevier Science B.V. All rights reserved.