Highly Selective Potassium Ion Responsive Liquid-Membrane Electrode

Abstract

Abstract The performance of a new liquid-membrane electrode using valinomycin as membrane component is described with respect to selectivity, working range, speed of response and accuracy. The electrode makes possible the measurement of potassium ion activities in the range of 10−1 M to at least 10−6 M in unbuffered systems with a selectivity of potassium over sodium ions of more than 4,000. The electrode was used for the direct titration of potassium ions.