Abstract: Afast and precise method was developed for the determination of the enantiomers of chiral pes-ticidc-uniconazole in soil. Matrix solid-phase dispersion (MSPD) technology was used to extract uniconazole from soil. MSPDconditions were optimized stepwise. The MSPD extract was directly used for quantitative determination of uniconazole by silica-based high performance liquid chromatography(HPLC) with UVdetection. The recoveries of uniconazole from three types of soils fortified at three levels of 0. 1, 1, 10 μg/g ranged from 75%-97% with RSDs<7%. On this basis, uniconazole was further isolated from the remainder of MSPD extract by silica-based HPLC and then subjected to chiral HPLCto determine its enan-tiomcric ratio. The determined ERs in the soils spiked with racemic uniconazole agreed sufficiently well with those in the standard solutions within the error limit of the method.

Key words: Chiral pesticide, Uniconazole, Enantiomeric ratio, Matrix solid-phase dispersion, Chiral HPLC