Determination Of Multi-residues Of Pesticides In Chinese Herbal Medicine By Accelerated Solvent Extraction-Capillary Gas Chromatography

Chinese herbal medicine(CHM), as a special plant, plays an important part in the health of the Chinese. The requirement of CHMs is on the increase, resultingly the cultivation of CHMs is depended on manpower. Because pesticides are applied to a broad variety of CHMs to reduce loss from insects, CHMs have a high risk of contamination of pesticides. So it is very important to strengthen the study on determination of pesticide residuces in CHMs.1. To establish an Accelerated Solvent Extraction (ASE) - capillary gas chromatography method for the determination of organochlorine pesticides (OCPs) residues in ginseng, Chrysanthemum and Raidx Astragali. Optimize the ASE conditions, and there are the best extraction conditions:the solvent of the mixture of n-hexane and acetone (4:1 in volume), the temperature 120℃, three cycling times, static time 10min, 100% flush volume. The extract was sulphonated with sulfuric acid to remove some interferential components and then analyzed by capillary gas chromatography with micro-Electron Capture Detector (μECD) by external and Internal standard methods. The concentration of OCPs showed good calibration curve with coefficient value of above 0.9990. The recovery was 62.8-110% with the relative standard deviations of 4.12-11.94%. The method was proved to be effective and practical.2. A method was developed for the determination of permethrin pesticides in Raidx Astragali by the Accelerated Solvent Extraction (ASE)-capillary gas chromatography. There are the extraction conditions:the solvent of the mixture of n-hexane and acetone (4:1 in volume), the temperature 100℃, three cycling times, static time 10min,100% flush volume. The extract was cleaned up with Column chromatography and then analyzed by capillary gas chromatography with micro-Electron Capture Detector (μECD) by external standard method. The concentration of permethrin showed good calibration curve with coefficient value of above 0.9990. The recovery was 70.4-90.74% with the relative standard deviations of 8.74%. The method was proved to be effective and practical.