Transient Potential Signals from Ion-Selective Electrodes Based on Plasticized Polymeric Membranes—Fundamentals and Applications

This review examines the reported research on the potential responses of ion-selective electrodes over time when exposed to sudden changes in the concentration of the primary ion (ion initially present in the ion-selective electrode membrane) and/or foreign interfering ions. Particular attention is given to the responses of liquid- and plasticized polymeric membrane-based ion-selective electrodes to foreign ions. The review provides an in-depth discussion of the theoretical models proposed to describe transient potential signals obtained experimentally with these ion-selective electrodes. In chronological order, the different contributions are presented and commented on in terms of their assumptions and mathematical treatments. The final equations obtained in each case, as well as some stages of their derivations, are presented. Additionally, the various models are classified and critically commented upon. Lastly, the review discusses the analytical applications reported for identifying and quantifying ions using the transient potential signals.