Construction of a novel highly selective potentiometric perchlorate sensor based on neocuproine–Cu(II) complex formed in situ during the conditioning period

Abstract

A potentiometric perchlorate-selective electrode based on a phenanthroline derivative, neocuproine (2,9-dimethyl-1,10-phenanthroline), was developed. An electroactive substance, a neocuproine complex of Cu2+, providing a selective response to perchlorate was formed in situ in the electrode membrane structure during the conditioning process. Membrane optimization studies showed that the most suitable membrane composition was 1.0% (w/w) neocuproine, 69.0% (w/w) o-nitrophenyloctylether (o-NPOE) and 30.0% (w/w) poly(vinyl chloride) (PVC) in terms of potentiometric performance characteristics. For the proposed electrode, the linear range, slope, detection limit, pH working range and response time were determined as 2.5 × 10–7–1.0 × 10–1 M, –53.01 mV/decade, 1.0 × 10–7 M, 4.0–12.5 and ≈3 s, respectively. The proposed sensor was successfully used in the determination of perchlorate contents of some perchlorate spiked tap, river and dam water samples.