Salicylate‐selective Potential Response of an Electrode Based on a Copper(II)‐phthalocyanine Derivative as an Ionophore

Abstract

Abstract Selectivity properties were established for salicylate‐selective electrodes prepared by incorporating 2,9,16,23‐copper(II)‐tetranitrophthalocyanine (Cu(II)TNPc) and 2,9,16,23‐copper(II)‐tetraaminophthalocyanine (Cu(II)TAPc) into plasticized poly(vinyl chloride) (PVC) membranes. The effect of nature of plasticizer, concentrations of ionophore and anionic and cationic additives on the potential response of the electrode was investigated. The PVC membrane electrode based on Cu(II)TNPc exhibited preferential selectivity for salicylate (Sal−) over other tested anions. The best potential response characteristics of a wide working concentration range 1.0×10−1–9.0×10−7 mol·L−1 and a limit of detection of 7.2×10−7 mol·L−1 with a slope of (−59.8±0.5) mV/decade were observed for the membrane containing (w/w) 3.0% Cu(II)TNPc, 67.0% o‐NPOE, 29.5% PVC, and 0.5% NaTPB. The proposed electrode with good stability and fast response could be used over a pH range of 3.0–7.0. And it was successfully applied to the determination of salicylate in actual samples with satisfactory results.