Nickel analysis in real samples by Ni2+ selective PVC membrane electrode based on a new Schiff base.

A newly synthesized Schiff base 3-aminoacetophenonesemicarbazone (AAS) has been used for the preparation of Ni(2+) selective PVC membrane electrode. The proposed electrode exhibits a Nernstian response over the nickel concentration range of 1.0×10(-7) to 1.0×10(-2)mol L(-1) with a slope of 30.0±0.3 mV/decade of concentration. The limit of detection as determined from the intersection linear segment of the calibration plot is 5.1×10(-8) mol L(-1). The electrode shows good selectivity towards nickel with respect to several alkali, alkaline earth, transition and heavy metal ions. The response time of the electrode is very fast (≥10 s) and can be used for 17 weeks in the pH range of 2.0-9.8. The electrode can also be used in partially non-aqueous media having up to 20% (v/v) methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. To investigate the analytical applicability of the electrode, it was successfully applied as an indicator electrode in Ni(2+) ion potentiometric titration with EDTA, and in direct determination of nickel(II) in real samples.