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 synthesized p-(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+, Ni2+, Co2+, Cu2+, Sr2+, Ba2+, Cs+, Pb2+, Zn2+, Mg2+, Cd2+, Al3+, Fe3+, and La3+. It could be employed successfully for the determination of Cr(III) ion activity in real samples.