Chromium(III)-selective Electrode Using p-(4-Acetanilidazo)calix[4]arene as an Ionophore in PVC Matrix

Abstract

A new poly(vinyl chloride) membrane, containing synthesizedp-(4-acetanilidazo)calix[4]arene as a membrane carrier, was used to fabricate a chromium(III) selective electrode. The optimum composition of the best performing membrane contained p-(4-acetanilidazo)calix[4]arene:DBBP:NaTPB:PVC in the ratio 10: 100: 1: 100 w/w. This electrode exhibited a near Nernstian slope of 19.8 ± 0.2 mV/decade of activity in the working concentration range of 9.8 × 10 -7 - 1.0 × 10 -1 M. It displayed a stable potential response in the pH range 2.8-5.7. The electrode exhibited a fast response time of less than 14 s and could be used for at least 12 weeks without any considerable divergence in potentials. This electrode showed very good selectivity over most of the common cations including Li + , K + , Na + , Ni 2+ , Co 2+ , Cu 2+ , Sr 2+ , Ba 2+ , Cs + , Pb 2+ , Zn 2+ , Mg 2+ , Cd 2+ , Al 3+ , Fe 3+ , and La 3+ . It could be employed successfully for the determination of Cr(III) ion activity in real samples.