MULTIIONOPHORE-BASED SOLID-STATE POTENTIOMETRIC ION SENSOR AS A CATION DETECTOR FOR ION CHROMATOGRAPHY

A new solvent/polymeric multiion-selective membrane electrode is described for use as a flow-through detector in ion chromatography. Unlike conventional ion-selective membranes that utilize only one type of ionophore, the multiion-selective membranes incorporate several different ionophores. In this study, a K+/NH4+/Na+/Ca2+ selective membrane has been prepared by incorporating four different neutral-carrier ionophores in a strongly adhesive polyurethane matrix. This membrane is cast on solid electrode surfaces, with no internal electrolyte solution, to form solid-state multiion sensors. The detection characteristics of the multiionophore membranes, which are controlled by the amounts and ratios of the ionophores they contain, are examined in a flow-injection arrangement. The sensors have been demonstrated in the target application, a flow-through ion chromatography system.