Analysis Of Pesticide Multiresidues In Chinese Medicinal Herbs

It is a serious problem that the pesticide residues exceeded maximum residue limit (MRL) in Chinese medicinal herbs. It not only affects the quality of Chinese medicinal herbs, but also our exports. Therefore, it is really significant to develop a simple, fast, available and efficient qualitative and quantitative method for measuring pesticide residues in Chinese medicinal herbs so as to ensure the quality and exports of Chinese medicinal herbs. Meanwhile, the research can provide efficient analytical method for establishing the quality standard of pesticide residues in Chinese medicinal herbs. The research chooses six kinds of Chinese medicinal herbs (Flos Lonicerae, Fructus Lycii, Cortex Phellodendri, Rhizoma Coptidis, Radix Glycytthizae, Raidix Paeoniae Alb), whose officinal parts include flower, fruit, root, stem and cortex, as samples, thirty-three kinds of pesticides that include organochlorine, organophosphorus pesticides, and pyrethroid as detecting objects to develop the multiresidue analytical method of pesticides. The main contents of the research are as follows:1. Established the multiresidue analytical method of organochlorine pesticides that extracting the sample with petroleum ether and ASE, Soxhlet and Vibrating instrument, cleaning up using oil of vitriol, detecting by gas chromatography equipped with electronic capture detector (ECD). The range of the recoveries is 79.7%-111.3%, 80.5%-112.3%, 60.8%-95.1%, respectively. And the minimum detectable concentration is 0.0001 mg/kg to 0.0003 mg/kg.2. Established the multiresidue analytical method of organophosphate pesticides that extracting the sample with dichloromethane and ASE, Soxhlet and Vibrating instrument, clean up using column packed with active carbon and Celete545 (v/v 1:4), detecting by gas chromatography equipped with FPD. The range of the recoveries at three levels is 75.4%-108.5%, 77.3%-109.6%, 51.2%-91.2% respectively. And the minimum detectable concentration is 0.01 mg/kg to 0.03 mg/kg.3. Established the multiresidue analytical method of Pyrethroid pesticides that extracting the sample with petroleum ether and ASE, Soxhlet and Vibrating instrument, clean up using column packed with Florisil, detecting by gas chromatography equipped with ECD. The range of the recoveries at three levels is 77.6%-108.3%, 76.8%-109.6%, 55.4%-89.6%, respectively. And the minimum detectable concentration is 0.001 mg/kg to 0.005 mg/kg.Comparing the extracting efficiency of organochlorine, organophosphate, and pyrethroid pesticide residues in the Chinese medicinal herbs by the three different methods that are...