Cadmium(II)-selective potentiometric sensor based on synthesised (E)-2-benzylidenehydrazinecarbothioamide for the determination of Cd2+ in different environmental samples

Abstract

ABSTRACT In the present study, we developed a cadmium(II)-selective sensor using a novel poly(vinyl chloride) membrane, containing synthesised (E)-2-benzylidenehydrazinecarbothioamide as an ionophore. This newly developed cadmium(II)-selective sensor exhibits best performance with a membrane composition of poly(vinyl chloride) (PVC), bis(2-ethylhexyl) adipate (DEHA), ionophore, potassium tetrakis (p-chlorophenyl) borate (KTpClPB) at 32.0:63.0:4.0:1.0 ratio (%, w/w). The cadmium(II)-selective sensor exhibits a lower detection limit of 1.77 × 10−6 mol L−1. This potentiometric sensor displays a stable potential response in the pH range of 5.0–10.0 and it shows a good selectivity for Cd2+ in the presence of interfering ions. The developed sensor shows a relatively fast response time (10 s), good reusability and stability. The proposed cadmium(II)-selective sensor was successfully applied as an indicator electrode in potentiometric titration of Cd2+ ions with EDTA and for the direct determination of Cd2+ ions in different environmental samples and in a waste battery sample.