GC Determination of Residual Organophosphorus Pesticides in Hangzhou White Chrysanthemum by Treatment of Samples with Single Extractant

Residual amounts of organophosphorus pesticides in samples of Hangzhou white chrysanthemum were extracted with acetone singly,and the extract obtained were purified by the CARB/NH2 SPE column. Eluate from the column was concentrated to 1-2 mL by rotary evaporation at 30 ℃ and then to ca. 0.4 mL by N2-blowing. After making up to 0.5 mL,the solution in acetone was used for GC determination. By using the DB-1701 quartz capillary chromatographic column,8 organophosphorus pesticides were separated and determined by NPD. Ranges of linearity of the working curves for these 8 pesticides were kept within 5.0 mg·L-1,and the values of detection limit (3S/N) found were in the range of 0.009-0.028 μg·g-1. Precision and recovery of the method were tested,and values of RSD′s (n=6) and of recovery found were in the ranges of 5.45%-7.27% and 67.3%-104.0% respectively.