Application of a Newly Synthesized Dioxime Derivative to Design and Characterize a Novel Electrochemical Nickel(II)–Selective Sensor

In this work, the suitability of a dioxime derivative, (2E,3E)-1,4- dihydroquinoxaline-2,3-dione dioxime (H2L), as a neutral ionophore for preparation of a PVC membrane electrode, is investigated for nickel(II) ion in solution. The prepared membrane exhibits a Nernstian response (28.2±0.1 mV decade-1) for Ni2+ ion over a wide concentration range (6.3×10-7 to 1.1×10-1 M) with a detection limit of 5.4×10-7 M. At a working pH range of 4.0–6.5, the proposed membrane electrode revealed very good selectivity for Ni2+ ion over a wide variety of other cations. Besides a relatively fast response of < 60 s the sensor could be used for at least 3 months without any considerable divergence in potentials. It was successfully applied as an indicator electrode in potentiometric titration of Ni(II) ion with EDTA and in the determination of Ni2+ in some water samples.