Abstract
A poly(vinyl chloride) membrane electrode with a copper(II) complex of 5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecahexenate (Me4DBTA) as the carrier is described. The electrode displays an anti-Hofmeister selectivity sequence with a preferential response towards salicylate and a linear potentiometric response towards salicylate ion from 2.5 x 10−6 to 1.0 x 10−1 mol l−1 with a slope of -57.4 mV dec−1 at pH 5.0. The transfer process of salicylate through the membrane containing Cu(II)-Me4DBTA was investigated by an a.c. impedance technique. The electrode has a satisfactory reproducibility and a rapid response time and can be applied to the determination of salicylate in human urine and pharmaceutical preparations.