Comparative Assessment of the Analytical Parameters in Ascorbic Acid and Sulphite Assay at a Spectrographic Carbon Working Electrode

Abstract

The aim of this study is the comparative investigation of spectrographic carbon electrode’s viability as working electrode, in ascorbic acid and sulphite asssessment. Cyclic voltammetry involves a linear sweeping of the potential, the analytical signal being represented by the anodic oxidation /cathodic reduction peak of the analyte. For both analytes, the electro-oxidation resulted in an anodic peak, correlable with ascorbic acid / sulphite concentration. The analytical range of linear response corresponded to 0.07 - 10 mM for ascorbic acid and to 15.5 mg/L - 4 g/L for sulphite. The relative standard deviation RSD (%) was 2.71 % for ascorbic acid and 2.88 % for sulphite. The sensitivities, given by the slopes of the calibration graphs were 88.88 μA/mmole/L for ascorbic acid and 477.37 μA/g/L for sulphite.