Influence of key parameters on the lower detection limit and response function of solvent polymeric membrane ion-selective electrodes

The lower detection limit of conventional polymeric membrane ion-selective electrodes (ISEs) is given by the release of measuring ions from the sensor membrane into the aqueous sample. It can be greatly improved by using inne r solutions of appropriate composition. Recently, steady-state model calcul ations have been used to predict the influence of various parameters on the response function and the lower detection limit. Among these, effects of t he composition of the inner solution, the presence of interfering ions in t he sample, the use of a flow-through cell, the polymer content and thicknes s of the ISE membrane, and the concentration of the membrane components hav e been investigated in the present work. All observed trends agree frilly w ith the theoretically predicted ones. (C) 2001 Elsevier Science B.V. Ali ri ghts reserved.