Polarographic reduction of pyruvic acid

The application of Delahay’s theory of kinetic polarographic currents as applied to the reduction of pyruvic acid has been examined. It is shown that the agreement between Delahay’s theory and the available data is more satisfactory, if one assumes that the current is controlled by the rate of the reaction between pyruvate ion and water molecule forming pyruvic acid and hydroxyl ion, than when one assumes the mechanism suggested by the earlier workers involving the rate of reaction between pyruvate ion and hydrogen-ion, both from the point of view of the magnitude of the diffusion current as well as its pH dependence. The results give an indication of the latter reaction being sluggish due to the activation energy requirements.