Fast response and selective perchlorate polymeric membrane electrode based on bis(dibenzoylmethanato) nickel(II) complex as a neutral carrier

Abstract

The feasibility of a synthesized bis(dibenzoylmethanato) Ni(II) complex (Ni(DBM) 2), as a novel ionophore for the preparation of a solid ion selective polymeric membrane (PVC) was tested. The ionophore has shown with the enhanced potentiometric selectivity toward perchlorate compared to other anions. The selectivity sequence of this electrode is as follows: ClO 4 − > SCN − > I − > CN − > ClO 3 − > NO 3 − > Br − > SO 3 − > BrO 3 − > F − > Cl −, which is a Hofmeister selectivity sequence. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0 × 10 −6 to 1.0 × 10 −1 M (0.138 μg mL −1 to 138 mg mL −1), a low detection limit (6.6 × 10 −7 M) and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (<5 S) and a wide pH independent range (1.2–12.5) in comparison with recent reported electrodes. The proposed electrode was used for the determination of perchlorate in water samples and human urine with satisfactory results.