HIGHLY SENSITIVE VOLTAMMETRIC ANALYSIS BY RE-OXIDATION OF REDUCED SUBSTANCES USING TWIN WORKING ELECTRODES

Abstract

A flow cell voltammetry with twin working electrodes was applied to the trace determination of reducible organic substances in the presence of dissolved oxygen. Carbazilquinone, one of quinone drugs, which is not oxidized by itself, was chosen as a sample. The first electrode was set at the reduction potential of carbazilquinone, and the second electrode at the oxidation potential of the reductant (hydroquinone). The cathodic current at the first electrode composed of reduction currents of dissolved oxygen andthe sample, while the anodic current at the second electrode depends solely on the reduced sample flowing toward the second electrode. The results of the determination based on the anodic current measurement were as follows; 1) The linear calibration plot was obtained from 0.3 nmole to 1.9 nmole of carbazilquinone. 2) The value of R.S.D. was less than 1%.