Salicylate-selective electrode based on lipophilic tin(IV)phthalocyanine

A new PVC membrane electrode based on lipophilic (2,9,16,23-tetra-tert-butylphthalocyanine)tin(IV) dichloride which demonstrates excellent selectivity and fast response toward the salicylate ion is described. The membrane electrode displayed a linear response for salicylate in the concentration range 10(-5)-0.1 M and exhibited an antiHofmeister pattern, with high selectivity for salicylate compared with lipophilic inorganic and biologically important organic anions. The electrode was successfully applied to the determination of salicylate in pharmaceutical preparations and biological samples.