An electrochemical Ni(II)-selective sensor-based on a newly synthesized dioxime derivative as a neutral ionophore

Abstract

The suitability of a dioxime derivative, (2 E, 3 E)-2 H-1,4-benzothiazine-2,3(4 H)-dione dioxime as a neutral ionophore for the preparation of a PVC membrane electrode for Ni(II) ions was investigated. It can be used for at least 4 months without any considerable divergence in potentials and it has a relatively fast response of <10 s. The prepared membrane exhibits a near Nernstian response for Ni 2+ ions over a wide concentration range (1.0 × 10 −6 to 1.0 M) with a detection limit of 1.6 × 10 −6 M. At a working pH range of 2.0–6.5 the proposed membrane electrode revealed very good selectivity for Ni 2+ ions over a wide variety of other cations. It was applied successfully as an indicator electrode in potentiometric titration of nickel ions with EDTA, and in the determination of Ni 2+ in some water samples.