Application of a Zeolite-Poly(vinyl chloride) Electrode to Potentiometric Studies of Alkali Metal Ions

Potentiometric electrodes based on the incorporation of zeolite particles into poly(vinyl chloride) (PVC) membranes are described. The electrode characteristics are evaluated regarding the response towards alkali ions. PVC membranes plasticized with dibutyl phthalate and without lipophilic additives (co-exchanger) are used throughout this study. The electrode exhibits a Nernstian response over the alkali metal cation concentration range of 1.0 × 10^?4 to 1.0 × 10^?1 M with a slope of 57.0 ± 0.9 mV per decade of concentration with a working pH range 3.0–9.0 and a fast response time of ≤15 s. The selectivity coefficients for cesium ion as test species with respect to alkaline earth, ammonium, and some heavy metal ions are determined. The proposed zeolite-PVC electrode is applied to the determination of ionic surfactant.