Abstract
A voltammetric study of ion transfer across an interface between two immiscible electrolyte solutions (ITIES) such as water (W) and an organic solution (O) interface (W/O) enables the observation of the dynamic feature of the ion transfer process based on the measurement of the current vs potential relationship from which one can determine simultaneously the transfer energy and the amount of the ion transferred. Thus, a voltammetric study of the ion transfer processes involved in a solvent extraction system provides fundamental insights into the thermodynamics, kinetics and the mechanism of solvent extraction. The present review highlights (i) the fundamental aspects of the ion transfer reaction across the ITIES, (ii) the principle of and procedures for the electrochemical observation of the ion transfer at the ITIES, (iii) various studies of the ion transfer processes involved in ion-pair extraction and chelate extraction systems, and (iv) a novel method for the separation of ions on the basis of the electrolytic ion transfer reaction.
