Coated-graphite electrode based on poly(vinyl chloride)-aluminum phthalocyanine membrane for determination of salicylate

Abstract

The construction performance characteristics and applications of a new polymeric membrane coated on graphite electrode with high selectivity toward salicylate are reported. The electrode was prepared by incorporating aluminum phthalocyanine chloride into a plasticized poly(vinyl chloride) membrane. The influence of several variables was investigated to optimize the potentiometric response of the electrode and to maximize the selectivity for salicylate over potentially interferent anions. Calibration plots with Nernstian slopes for salicylate were observed, -59 ± 1 mV/decade, over a linear range of more than four decades of concentration (5 × 10-6 to 1 × 10-1 M salicylate) with good precision and low detection limit. The electrode is highly selective toward salicylate over several inorganic and organic anions. Response time of the electrode is ≤30 s over the entire concentration range. The electrode was successfully applied to the determination of salicylate in pharmaceutical preparations and biological samples, © 1999 Academic Press.