Stir bar sorptive extraction applied to the determination of dicarboximide fungicides in wine

The dicarboximide fungicides vinclozolin, iprodione and procymidone were analyzed in white wines using stir bar sorptive extraction (SBSE) in combination with thermal desorption-capillary GC-MS analysis (TD-cGC-MS). The method was optimized using spiked water samples in a concentration range between 0.5 and 100 mug/l. Iprodione was measured as its degradation product 3,5-dichlorophenyl hydantoin. Limits of quantification in the full scan MS mode are 0.5 mug/l for vinclozolin and procymidone and 5 mug/l for iprodione. In the ion monitoring mode, concentrations 100 times lower can be dosed. Because of wine matrix effects on the recoveries, quantification of the target fungicides in wine had to be carried out by standard addition. For the thermolabile iprodione, the accuracy of SBSE-TD-cGC-MS was verified using SBSE followed by liquid desorption and analysis by liquid chromatography -atmospheric pressure chemical ionization mass spectroscopy. Procymidone and iprodione were detected in wines in concentrations up to 65 mug/l while the highest concentration of vinclozolin detected was smaller than 3 mug/l. (C) 2001 Elsevier Science B.V. All rights reserved.