Potassium and sodium ion sensor based on amperometric ion selective electrode

Abstract

The interface between nitrobenzene solution containing an ionophore bis[(benzo-15-crown-5)-4́-ylmethyl]-pimelate and water {NB(BB15C5)/W} works satisfactorily as an ion selective electrode (ISE) for voltammetric or amperometric determination of K+ and Na+ ions. On this interface, the half-wave potential of the transfer of K+ and Na+ ions are separated enough for simultaneous determination of the two ions with one electrode. This interface was stabilized by covering itself with a hydrophilic semipermeable membrane (a dialysis membrane). The membrane-covered ISE sensor was easy to be fabricated, convenient for handling and stable more than a month. The covered membrane also protects the ISE surface from contamination by interferents such as solids and polymeric substances in a test solution. The response time of the ISE sensor was about 20 s and the response current was proportional to the concentration of the analyte ions. The dual pulse amperometric technique developed for the simultaneous determination of K+ and Na+ ions was successfully applied to the analysis of foods. © 1990, The Japan Society for Analytical Chemistry. All rights reserved.