[Determination of organochlorine pesticide residues in nine herbs by solid-phase extraction and capillary gas chromatography].

The solid-phase extraction and capillary gas chromatography was introduced for determining 13 organochlorine pesticide residues including alpha-benzene hexachloride (BHC), betaBHC, gamma-BHC, delta-BHC, p,p'-dichloro-diphenyl-dichloroethylene (pp'-DDE), p,p'-dichloro-di-phenyl-dichloroethane (pp'-DDD), o,p'-dichloro-diphenyl-trichloroethane (op'-DDT), pp'-DDT, heptachlor (HEPT), aldrin, heptachlor epoxide (HCE), dieldrin and endrin in Scutellaria baicalensis, Salvia miltiorrhiza, Belamcanda chinensis, Paeoniae lactiflora, Angelica dahurica, Arisaema erubescens, Fructus arctii, Anemarrhena asphodeloides and Platycodon grandiflorum. The organochlorine pesticides were extracted from herbs with mixed solvents of acetone and n-hexane by ultrasonic and cleaned up by Florisil solid-phase extraction column. Then, the extract was separated by capillary column (30 m x 0.25 mm i.d. x 0.25 microm) and detected by electrochemical detector. The carrier gas was N2 (99.999%) with the flow rate of 1.4 mL/min. The split ratio was 1:2.2. The injector temperature was 220 degrees C and the detector temperature was 330 degrees C. The column temperature was increased by the rate of 20 degrees C/min from 100 degrees C to 190 degrees C (hold for 1. 0 min), then to 235 degrees C by the rate of 4 degrees C/min and hold for 7 min at 235 degrees C. The good linearities were obtained for 13 organochlorine pesticides. The detection limits were between 0.064-0.61 microg/L. The average recoveries were between 87.3%-102.3% and relative standard deviations of 1.3%-6.8%. The method is effective, fast and accurate.