Simultaneous detection of ascorbic acid and sulfur dioxide on a poly(3,4-ethylenedioxythiophene) covered gold electrode

For wine industry, the quality of the produced wine is very important. Sulfur dioxide (SO₂) is used as an antioxidant and preservative. But also ascorbic acid plays an important role in preventing oxidation. Therefore, there is a need for detecting these components in wines. Cyclic voltammetry was used to determine SO₂ and ascorbic acid in a pH 3.3 model wine solution. In literature, modified electrodes showed advantages compared to bare electrodes. For this reason a gold electrode covered with poly(3,4-ethylenedioxythiophene) (PEDOT) was used. In the simultaneous presence, well defined separated current peaks for SO₂ and ascorbic acid were detected, which proved the excellent suitability of the PEDOT covered gold electrode for precise determination. A linear relationship between concentration and peak current was observed.