Kinetic–potentiometric determination of iodide with an antimony(V) coated-wire ion-selective electrode

Abstract

A coated-wire Sb^v ion-selective electrode has been used to study the iodide-catalysed reaction between hexachloroantimonate(V) and hydroxylamine, and a kinetic method for the determination of iodide is proposed. Under the selected experimental conditions of 1 × 10^–6 mol dm^–3 SbCl₆–, 8 × 10^–2 mol dm^–3 NH₂OH, 1 × 10^–1 mol dm^–3 HCl and 25 ± 0.1 °C, iodide can be determined in the range 0.01–0.40 µg cm^–3 with good selectivity. The method is simple and inexpensive and has been applied satisfactorily to the determination of iodide in common iodinated salts.