Sodium-selective polymeric membrane electrodes based on calix[4]arene ionophores

Abstract

Sodium-selective electrodes were prepared with polymeric membranes containing ester and ketone derivatives of p-tert-butyl calix[4]arene. The electrodes were prepared with 2-nitrophenyl octyl ether as the solvent mediator and potassium tetrakis(p-chlorophenyl)borate as the ion exchanger in a poly(vinyl chloride) matrix. Several of the ligands examined produced electrodes with near-Nernstian slopes, detection limits of ca. 10^–5 M for sodium and excellent selectivity against a range of common cations.