Study of reactant and product adsorption in double potential step and related pulse techniques: Part III. Differential pulse polarography (DPP) and differential normal pulse polarography (DNPP)

Abstract

The analytical solution for differential pulse polarography (DPP) and differential normal pulse polarography (DNPP) for a reversible charge transfer reaction when reactant and product are adsorbed on a plane electrode following a linear isotherm has been derived. The DPP peak currents obtained from this solution are enhanced only when adsorption of the reactant or product occurs, and this is in agreement with previous results from the literature which were obtaining using numerical methods. In contrast, the DNPP response, which had not been described yet, shows that the peak currents will be depressed if only the product adsorbs, although they are also enhanced when adsorption of the reactant only is involved. The dependence of the DPP and DNPP responses on the adsorption coefficients, the pulse amplitude, and the drop and pulse durations is discussed.