Elementary features of depletive stripping chronopotentiometry

The fundamental characteristics of the stripping chronopotentiometry (SCP) E versus t and dt/dE 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 dt/dE 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 dt/dE peak with practical expressions for the peak potential Ep and the peak half-width w1/2 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 Ep and w1/2. This approach appears to provide a good basis for understanding experimental data obtained at mercury microelectrodes and macroelectrodes (HMDE). Under standard conditions, the SCP dt/dE versus E peaks are significantly narrower than those obtained with transient SV modes, establishing the better resolution capabilities of SCP.