Free sulphite determination in wine using screen-printed carbon electrodes with prior gas-diffusion microextraction

•Non-mediated electrochemical detection of sulphites•Sulphite extraction by membrane-mediated gas diffusion•Electroanalysis with non-modified screen-printed carbon electrodes

Gas-diffusion microextraction was employed in the extraction of sulphites in wines aiming their electrochemical determination, which was achieved by square-wave voltammetry using screen-printed carbon electrodes. Sulphites are additives commonly used in many produced goods, particularly food products. The developed methodology showed good limits of detection (0.4 mg L− 1) and quantification (1.3 mg L− 1). The proposed method was also compared with the reference methodology used by the wine industry (the Ripper method, an iodometry) showing no significant differences in the obtained results. Therefore, a simple, cheap and portable alternative for the determination of sulphites in wine is presented.

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