Development of all solid state chromium(III) selective sensor by using newly synthesized triazole derivative as an ionophore in PVC matrix

Abstract

A new poly(vinyl chloride) membrane based all solid state electrochemical sensor containing synthesized triazole compound namely 4-(5-bromothiophen-2-carboxylidene amino)-3-methyl-5-mercapto-s-triazole (BTMMT) as an electroactive material was prepared and investigated as a chromium(III) selective sensor. The optimum composition of the best performing membrane contained triazole:NaTPB (sodiumtetraphenylborate):NPOE (nitrophenyl octyl ether):PVC in the ratio 10:2:50:38 (w/w). The sensor exhibited near Nernstian slope of 19.8±0.2mV/decade of activity in the working concentration range of 2.0×10−7 to 1.0×10−1M. It displayed a stable potential response in the pH range 2.2–5.0. The sensor exhibited a fast response time of 10–15s and could be used for at least three months without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Li+, K+, Na+, Ni2+, Co2+, Cu2+, Sr2+, Ba2+, Cs+, Pb2+, Zn2+, Mg2+, Cd2+, Fe3+, and La3+. Also, it was successfully used for the determination of Cr(III) activity in the waste from electroplating, and lather tanning industry.