A potassium-selective electrode with solid internal contact.

The performance characteristics of potassium-selective electrodes made with valinomycin membranes plasticized with dioctyl adipate or sebacate, and with a solid silver contact or an internal solution, have been critically examined. The choice of electrode depends on a number of factors, including the interfering ion(s) present. The electrodes can be used for determination of potassium in natural waters.