Highly selective thiocyanate electrode based on bis-bebzion Schiff base binuclear copper(II) complex as neutral carrier

摘要

A highly selective polyvinyl chloride (PVC) membrane electrode, based on N,N'-(aminoethyl)ethylenediamide bis(2-benzoideneimine) binuclear copper(II) complex [Cu(II)-AEBB] as neutral carrier, was prepared for thiocyanate (SCN-) determination, which displays an anti-Hofmeister selectivity sequence for a series of anions in the following order: SCN- > ClO4- > Sal(-) > I- > NO3- > Br- > Cl- > NO2- > SO32- > F- > H2PO4- > SO42-. The electrode exhibited near-Nernst response for SCN- with a slope of -59.0mV/decade over a wide concentration range (8.5 x 10(-7) similar to 6.8 x 10(-1) mol/L) with a detection limit of -5.0 x 10(-7) mol/L in pH 5.0 phosphate buffer solution at 25 degrees C. Alternating current (AC) impedance and equivalent circuits were used to investigate the thiocyanate response mechanism of the membrane doped with [Cu(II)-AEBB].