OBJECTIVETo determine organochlorine pesticide residue in 9 Chinese herbs.

METHODSThe organochlorine pesticides were extracted from the herbs with mixed solvents of n-hexane and acetone by a solid-phase extraction cartridge Florisil. Capillary gas chromatography was used to separate the samples.

RESULTSGood linearities were obtained for 11 organochlorine pesticides. The average recoveries at two concentration levels ranged from 79.9% to 89.0%,and from 86.3% to 104.8%, with relative standard deviations of 1.8% to 7.1%, respectively and detection limit of 2 g/kg. The residues of the organic pesticides exceeded national standard in Pogostemon cablin and Panax notoginseng.

CONCLUSIONCapillary gas chromatography combined with electron capture detection provides a practical means for detecting organic pesticide residue in Chinese herbal medicines, and the limits of pesticide residues should be formulated in Chinese pharmacopoeia.