OBJECTIVETo establish a method for the simultaneous determination of 15 pesticides residues in Radix Paeoniae Alba by large volume injection-gas chromatography-mass spectrometry(LVI-GC-MS).

METHODSThe pesticides, including organochlorine pesticides, organophosphorus pesticides and pyrethroid insecticides, were analyzed by LVI-GC-MS using DB-5MS capillary column (30 m X 250 μm, 0.25 μm). The column temperature programming: initial temperature 40 degree for 1 min, with the increasing rate of 20 degree/min to 210 degree for 2 min, then with the increasing rate of 5 degree/min to 280 degree for 22 min. The flow of carrier gas was 1.0 ml/min with the injection volume of 15 μl.

RESULTSThe calibration curves of the pesticides were linear in the specified concentration ranges with correlation coefficients of 0.9937-0.9995. The average recoveries of the pesticides in Radix Paeoniae Alba spiked at two spiked levels ranged from 60.4 % to 106.8 % (for pendimethalin and 4, 4'-DDE those were 53.1 % and 45.2 %) with relative standard deviation(RSD) of 3.6 % to 18.6 % and the detection limits (S/N=3) were in the range of 0.16 μg/kg to 3.59 μg/kg.

CONCLUSIONThe established method for determination of multi-pesticide residue in Radix Paeoniae Alba is rapid, convenient and accurate with high sensitivity and low-cost.