A novel potentiometric sensor for the determination of Pb(II) ions based on a carbothioamide derivative in PVC matrix

Abstract

In this research, a carbothioamide derivative molecule was synthesized to be used as an electroactive material, and poly (vinyl chloride) (PVC) membrane lead(II)–selective potentiometric sensors with different components were prepared. Among various compositions, the best potentiometric performance was exhibited by the membrane having the electroactive material, bis(2–ethylhexyl)sebacate (BEHS), PVC, and potassium tetrakis(p–chlorophenyl)borate (KTpClPB) in the ratio of 4.0:63.0:32.0:1.0 (w/w). The proposed sensor exhibited a Nernstian response in the concentration range of 1.0×10-5–1.0×10-1 mol L-1 with a slope of 29.5±1.6 mV/decade. The detection limit of the sensor was 3.96×10-6 mol L-1. The potentiometric response of the lead(II)–selective sensor was independent of pH of test solution in the pH range of 5.0–9.0. The developed sensor had very good repeatability, stability, and selectivity, as well as a response time of 5s. These novel lead(II)–selective sensors, produced cost–efficiently, have been successfully used as an indicator electrode for the potentiometric titration of Pb(II) against EDTA and for the determination of Pb(II) ions in different water samples.