POTASSIUM-SELECTIVE ELECTRODE BASED ON A CALIX[6]ARENIC ESTER (C6Es6)

An ion-selective electrode (ISE) was elaborated based on a calyx[6]arenic ester (C6Es6) as ionophore and PVC as polymer matrix. Potentiometric measurements were performed in standard solutions of Ca2+, Mg2+, Na+, K+, NH4+ and Li+. The best response was observed for K+: slope 52 mV/Delta pK; linear range from 0.1 mM up to 0.1 M; detection limit of 0.02 mM; potentiometric selectivity coefficients of 0.06 and 0.16 for Na+ and NH4+, respectively.