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All-solid-state electrodes are increasingly being used in clinical, industrial and environmental analysis. This wide range of applications requires deep theoretical description of such electrodes. This work concentrates on the development of a numerical tool for the qualitative prediction of electrochemical behaviour for solid-contact ion-selective electrodes at low analyte concentrations. For this purpose, a general approach to the description of electro-diffusion processes, namely the Nernst-Planck-Poisson (NPP) model, was applied. The results obtained from this model are verified by experimental data of lead(II)-selective electrodes based on a polymeric PVC membrane with polybenzopyrene doped with Eriochrome Black T used as the solid contact. [ABSTRACT FROM AUTHOR]

Abstract: The Nernst–Planck–Poisson (NPP) model is a general approach to the description of the electro-diffusion processes which lead to the formation of the membrane potential. It takes into consideration several parameters of ion-selective electrodes (ISEs) which are ignored in simpler models. This paper presents a critical comparison between the NPP model and simpler models. The influence of different parameters on the detection limit of ISEs is discussed. This is achieved by comparing direct predictions of the models and, in contrast to any earlier treatment, by inverse modelling. This makes it possible to simultaneously find out which set of physical parameters of the system will produce the desired detection limit. [ABSTRACT FROM AUTHOR]