Evaluation of an overdetermined system based on multiple ion-selective electrodes of the same type

Possible advantages of using multiple ion-selective electrodes of the same type for the determination of analyte ions in multicomponent mixtures are investigated. Specifically, potassium and ammonium ions are determined in model multicomponent mixtures with a combination of four valinomycin and four nonactin polymeric membrane electrodes. The electrode potentials are monitored by a specially designed data-acquisition system, and conventional matrix operations are used to calculate the ion concentrations. The results indicate that greater confidence in the analyses can be obtained from an overdetermined system of this type.