Application of Current Fluxes to the Characterization of Ion Transfer at Solvent Polymeric Membranes with One and Two Polarized Interfaces

Chronopotentiometric and reciprocal derivative chronopotentiometric E–t, dt/dE–E and dI/dE–E responses are analyzed for the ion transfer of a series of tetraalkylammonium cations and tricyclic catamphiphilic drugs, driven by an exponential and a constant current flux in a liquid membrane system of one and two polarized interfaces. Reciprocal derivative chronopotentiometry shows a strong resolving power, since the dt/dE–E and dI/dE–E responses obtained with this technique are narrower than those provided by some of the more powerful voltammetric techniques, like square wave voltammetry and differential pulse voltammetry. From the experimental results we have obtained the standard ion transfer potential of the different ions assayed.