Highly Selective Iodide Membrane Electrode Based on a Cerium Salen

Abstract

A highly selective PVC membrane electrode based on a cerium-salen complex was prepared. The sensor displays an anti-Hofmeister selectivity sequence with a preference for iodide ion over many common organic and inorganic anions. The proposed electrode exhibits a near-Nernstian behavior over a wide concentration range (5.0 × 10^-2 - 8.0 × 10^-6 M) with a slope of 57.5 mV per decade, and a detection limit of 6.0 × 10^-6 M. The electrode has a very fast response time and can be used in the pH range of 3.0 - 11.0. It was applied, as an indicator electrode, in potentiometric titration of Ag⁺ ions.