Tetraalkylammonium Ion-selective Electrodes with Supporting Electrolytes. An Experimental Test of the Theory of Liquid Ion-exchange Membrane Ion-selective Electrodes Based on the Concept of the Mixed Ion-transfer Potential

Selectivity characteristics of liquid-membrane ion-selective electrodes for tetraethylammonium and triethylmethylammonium ion-selective electrodes in the presence of homologous tetraalkylammonium ions as interfering ions were studied with supporting electrolytes both in the liquid membrane and in the sample solution. The emf vs. logarithm of the concentration of the primary ion curves in the presence of interfering ion were well described by the theory of liquid-membrane ion-selective electrodes which is based on the concept of the mixed ion-transfer potential at the liquid-membrane/sample solution interface. The dependence of the selectivity coefficients on the concentrations of the primary ion in the liquid membrane and of the interfering ion in the sample solution agreed well with the theoretical prediction.