A PTEV-based zeolite membrane potentiometric sensor for cesium ion

Potentiometric electrodes based on the incorporation of zeolite particles into poly (tetrafluoroethylene-co-ethylene-co-vinylacetate) (PTEV) membranes are described. The electrodes characteristics are evaluated regarding the response towards cesium ion. PTEV membranes plasticized with benzyl acetate and silicon oil, in the absence of any lipophilic additive (co-exchanger), was used throughout this study. The electrode exhibits a Nernstian response over a cesium concentration range of 1.0 x 10(-4) to 1.0 x 10(-1) M (r = 0.998) with a slope of 58.0 +/- 0.8 mV per decade of concentration, and a detection limit of 8.0 x 10(-5) M. The electrode possesses a fast response time (15 s in solution of greater than or equal to 1.0 x 10(-4) M Cs+ ion) and a wide working pH range (4.0-8.0). The selectivity coefficients for Cs+ ion with respect to alkali, alkaline earth, ammonium and some heavy metal ions were investigated. The determination of Cs+ ion is accomplished by its potentiometric titration using the proposed electrode as an indicator electrode. (C) 2003 Elsevier B.V. All rights reserved.