Differential pulse voltammetry for ion transfer at liquid membranes with two polarized interfaces.

A simple analytical expression for the response of the double-pulse technique differential pulse voltammetry (DPV) corresponding to ion transfer processes in systems with two liquid/liquid polarizable interfaces has been deduced. This expression predicts lower and wider curves than those obtained with a membrane system with a single polarizable interface. Moreover, the peak potential of these systems is shifted 13 mV from the half-wave membrane potential. We have applied this expression to study the ion transfer of drugs with different pharmacological activities (verapamil, clomipramine, tacrine, and imipramine), at a solvent polymeric membrane ion sensor.