SODIUM-SELECTIVE POLYMERIC MEMBRANE ELECTRODES BASED ON CALIX[4]ARENE DERIVATIVES

Abstract

Four kinds of lipophilic calix[4]aryl ester derivatives (A)-(D) have been designed for Na⁺-selective polymeric membrane electrodes. On the ion selectivity of (A)-based electrode, the phenyl ether type membrane solvent, especially FPNPE is superior to the diester type ones in Na⁺ selectivity against K⁺. On the contrary, in the Na⁺ electrode of (B), de-tert-butylated derivative of (A), the diester type solvent, DOP gave good result. The selectivity coefficients for Na⁺ with respect to K⁺ (-log k^Pot_NaK) being nearly 2.5. The (B)/DOP-based Na⁺-selective electrode was successfully applied to Na⁺ assay in human blood sera.