Pervaporation-gas chromatography coupling for slurry samples. Determination of acetaldehyde and acetone in food.

The use of pervaporation for the removal of volatile species from slurry samples, with a full automated introduction of the sample into the lower chamber of the pervaporation unit prior to their individual separation and determination by gas chromatography-flame ionisation detection, is presented for the first time. For this purpose, the upper chamber of the pervaporator is situated in the loop of an HPLC injection valve and the only requirement of the experimental setup for being used with slurries is to have adequately sized diameters for the units of the dynamic manifold assisting the donor chamber in order to avoid clogging by the suspended particles. The method developed was applied to the determination of acetaldehyde and acetone in food samples with different solids contents, such as yoghurt, Actimel and different kind of juices.