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+.