Coated-wire copper(II)-selective electrode based on phenylglyoxal-α-monoxime ionophore

摘要

A copper(II) ion-selective electrode based on a recently synthesized 2-quinolyl-2-phenylglyoxal-2-oxime (phenylglyoxal-α-monoxime) has been developed. The PVC-based membrane containing phenylglyoxal-α-monoxime, dibutyl phthalate as plasticizer, and sodium tetraphenylborate as anion excluder and membrane modifier, was directly coated on the surface of a platinum-wire electrode. The response of the electrode was linear with a near-Nernstian slope of 28.2 mV decade~(-1) mol L~(-1). The response time for the proposed electrode to achieve a 95 steady potential for Cu~(2+) concentrations ranging from 1 * 10~(-1) to 1 * 10~(-6) mol L~(-1) is between 10 and 50 s, and the electrode is suitable for use within the pH range of 3 to 6.5. The electrode has a detection limit of 5 * 10~(-7) mol L~(-1) Cu~(2+) and its selectivity relative to several alkali, alkaline earth, transition,and heavy metal ions was good. The coated-wire electrode could be used for at least two months without a considerable alteration of its potential. applications of the electrode for determination of copper in milk powder samples and as an indicator electrode for potentiometric titration of Cu~(2+) ion using EDTA are reported.