Analysis of low-volatility organic sulphur compounds in wines by solid-phase microextraction and gas chromatography.

A method for analysing low-volatility sulphur compounds using solid-phase microextraction has been developed. The analytes were extracted directly from the liquid sample using fibres coated with different stationary phases. The best extraction efficiency was obtained with Carboxen-polydimethylsiloxane coating. Ionic strength, sample volume, time and temperature of the extraction were optimised and the matrix effect studied. The method enables 15 sulphur compounds in wine to be determined at trace levels with recoveries close to 100% and limits of detection between 0.05 and 5 microg/L. The overall method was successfully applied to the determination of the sulphur compounds studied in several red, white and rosé wines.