An Interference-Free Voltammetric Method for the Detection of Sulfur Dioxide in Wine Based on a Boron-Doped Diamond Electrode and Reaction Electrochemistry

This paper describes a new, simple, and highly selective analytical technique for the detection of sulfur dioxide in wine, as a real sample with a relatively complicated matrix. The detection of the above analyte was based on the electrogeneration of iodine from iodide on a boron-doped diamond electrode, without modifications, in the presence of 0.1 mol dm(-3) HClO4 as a supporting electrolyte. The electrogenerated iodine reacted with sulfur dioxide, forming iodide ions and sulfuric acid (i.e., a Bunsen reaction). The product of this reaction, the iodide ion, diffused back to the surface of the boron-doped diamond electrode and oxidized itself again. This chemical redox cycling enhanced the voltammetric response of the boron-doped diamond electrode. The selectivity of the determination was assured using NaOH and formaldehyde during sample preparation, and a blank was also measured and taken into account. The detection limit was estimated to be 10(-6)-10(-7) mol dm(-3). However, the content of sulfur dioxide in wine is significantly higher, which can lead to more accurate and reliable results.

Automated summary

This paper presents a new, simple, and highly selective analytical technique for the detection of sulfur dioxide in wine. The technique is based on the electrogeneration of iodine from iodide on a boron-doped diamond electrode. The selectivity of the determination is ensured through sample preparation and the inclusion of a blank measurement.