Solid-phase microextraction coupled with high performance liquid chromatography: a complementary technique to solid-phase microextraction-gas chromatography for the analysis of pesticide residues in strawberries

Solid-phase microextraction coupled with high performance liquid chromatogr aphy has been studied for the analysis of methiocarb, napropamide, fenoxyca rb and bupirimate in strawberries. The strawberries were blended and centri fuged. Then, an aliquot of the resulting extracting solution was subjected to solid-phase microextraction (SPME) on a 60 mum polydimethylsiloxane/divi nylbenzene (PDMS/DVB) fibre for 45 min at room temperature. The extracted p esticides on the SPME fibre were desorbed into SPME/high performance liquid chromatography (HPLC) interface for HPLC analysis with diode-array detecti on (DAD). The method is organic solvent-free for the whole extraction proce ss and is simple and easy to manipulate. The detection limits were shown to be at low mug kg(-1) level and the linear response covered the range from 0.05 to 2 mg kg(-1) of pesticides in strawberries with a regression coeffic ient larger than 0.99. A good repeatability with RSDs between 2.92 and 9.25 % was obtained, depending on compounds.