SALICYLATE-SENSITIVE MEMBRANE-ELECTRODE BASED ON COPPER(II) TETRAAZA[14]ANNULENE MACROCYCLIC COMPLEX

A poly(vinyl chloride) membrane electrode with a copper(II) complex of 5, 7, 12, 14-tetramethyldibenzo[b,i] [1, 4, 8, 11]tetraazacyclotetrad ecahexenate (Me(4)DBTA) as the carrier is described. The electrode dis plays an anti-Hofmeister selectivity sequence with a preferential resp onse towards salicylate and a linear potentiometric response towards s alicylate 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 thr ough the membrane containing Cu(II)-Me(4)DBTA was investigated by an a .c. impedance technique. The electrode has a satisfactory reproducibil ity and a rapid response time and can be applied to the determination of salicylate in human urine and pharmaceutical preparations.