An analytical method that combines gas-diffusion microextraction with square-wave voltammetric detection using commercial non-modified screen-printed carbon electrodes was employed in the determination of total sulphites in beer. The developed methodology showed low limits of detection (0.050 mg L-1) and quantification (0.17 mg L-1) and an intraday precision of 4.8%.
The proposed method was also compared with a reference methodology used in the beer industry (EBC method 9.25.3) showing no significant differences in the obtained results. This is a simple, cheap and notably portable alternative for brewers that wish to quantify sulphites in their products.