Elementary features of depletive stripping chronopotentiometry

Abstract

The fundamental characteristics of the stripping chronopotentiometry (SCP) E versus t and d t/d E versus E curves are explored for the non-complex metal-only case in the limit of complete depletion of accumulated metal from the electrode volume. In contrast with the surface area of the d t/d E peak, which yields a straightforward quantitation of the accumulated metal, the potential–time dependence is quite involved. Thus the derivation of a rigorous theoretical representation of the d t/d E peak with practical expressions for the peak potential E p and the peak half-width w 1/2 would be difficult, if not impossible. Nevertheless, complete depletion conditions (relatively low stripping currents) allow for the application of a fairly simple Nernstian model that leads to estimates of E p and w 1/2. This approach appears to provide a good basis for understanding experimental data obtained at mercury microelectrodes and macroelectrodes (HMDE). Under standard conditions, the SCP d t/d E versus E peaks are significantly narrower than those obtained with transient SV modes, establishing the better resolution capabilities of SCP.