Potassium ion-selective membrane electrode based on heterogeneous precipitate and PVC matrix

A membrane consisting of PVC impregnated with a heterogeneous precipitate of potassium cobalticarbonate is prepared to selectively detect K⁺ ion in aqueous system. The electrode exhibited near Nernstian response for K⁺ ion over a wide concentration range of 1x10⁻⁵M to 1x10⁻¹M with a limit of detection 10⁻⁵ M. It has fast response time of approximately 2–3 sec and can be used for 3–4 months without observing any major deterioration. It is free from interference from ions like Na⁺ and Li⁺.