SONOVOLTAMMETRIC BEHAVIOR OF ASCORBIC-ACID AND DEHYDROASCORBIC ACID AT GLASSY-CARBON ELECTRODES - ANALYSIS USING PULSED SONOVOLTAMMETRY

The effect of power ultrasound on the voltammetric behavior of ascorbi c acid and dehydroascorbic acid at a glassy carbon electrode is descri bed. The voltammetric characteristics of both compounds were found to be modified by ultrasonically formed radicals. In the case of dehydroa scorbic acid the single sweep voltammogram shows an anodic signal in t he presence of ultrasound which probably results from the formation of an oxidizable radical known to be an intermediate of ascorbic acid ox idation. In the case of ascorbic acid pulsed sonovoltammetry is applie d and characterized regarding the time dependence of the current decay and the reliability of its analytical performance. The utility of pul sed sonovoltammetry is demonstrated analyzing a pain killer tablet reg arding the ascorbic acid content.