Stripping chronopotentiometry at scanned deposition potential (SSCP). Part 4. The kinetic current regime

The theory for depletive stripping chronopotentiometry at scanned deposition potential (SSCP) has been extended to include the case of kinetic currents. Invoking the Koutecký–Koryta approximation, i.e., assuming a spatially discontinuous transition from labile to non-labile behaviour, allows a rigorous expression to be obtained for the full SSCP wave. Theoretical predictions are supported by experimental data for the quasi-labile Cd–NTA system at a conventional HMDE and a mercury microelectrode. The characteristic features of the SSCP wave for systems influenced by homogeneous kinetics allow dynamic speciation characteristics to be unambiguously identified and discriminated from those due to irreversibility in the electrochemical reaction or heterogeneity in the chemical speciation.