ELECTROOXIDATION OF THEOCYANATE ON THE COPPER-MODIFIED GOLD ELECTRODEAND ITS AMPEROMETRIC DETERMINATION BY ION CHROMATOGRAPHY

Cyclic voltammetry was used to investigate the electrochemical behavio r of an Au/Cu electrode towards the electrooxidation of thiocyanate io n in alkaline medium, The effects of pH, copper loading, scan rate and applied potential on the electrocatalytic oxidation of thiocyanate ha ve been investigated. Flow injection experiments and ion-chromatograph y (IC) were performed to characterise the electrode as an amperometric sensor for the thiocyanate determination. The effects of carbonate co ncentration and common interferents on the retention time were also es timated, The electrode stability, precision, limit of detection and li near range were evaluated at a constant applied potential of 0.7 V vs. Ag/AgCl. Calibration plots, obtained in IC, were linear from 1.0 to 1 95 mu M (correlation coefficient of 0.9984), The detection limit (LOD) was 0.5 mu M (29 ppb) in a 50 mu l injection. An example of analytica l application, which includes the IC separation and detection of thioc yanate ion present in human urine, is given.