A Method For Determining Multi-residues Of Pyrethroid Pesticides In Ginseng

Ginseng is indispensable constituents of the human meal throughout the world. Thus agricultural production may represent a important source of human exposure to pesticide residues. After high toxic organophosphates pesticide was forbidded. Pyrethroids are widely used as pest control agents in ginseng because of their low toxicity, high efficiencies and their non-persistence in the environment. However, the use of pesticide in pest control agents has led to the existence of pesticide residues in ginseng, the part of pesticides could lead to serious problems on the abnormal and mutagenic action development of human. So pyrethroid pesticide residues can remain in question has already become the main cause of ginseng export blocked. As a result, establishment of sample preparation techniques for pyrethroids residues in ginseng is urgent matter.A method for determining multi-residues of permethrin, bifenthrin, baythrioid, fenvalerate, deltamethrin, fenpropathrin, lambda-cyhalothrin in Ginseng samples by using GC has been developed. The main study content is listed as follows:Homogenization and solid-phase extraction method for the clean-up the extracts of pyrethroid insecticide residues in ginseng was optimized. The effects of different extracted solvent on the clean-up of seven pyrehtroids in the ginseng sample were investigated. The recoveries of three standard addition levels of high, medium, low concentrations were 93.9%-103.3%(permethrin),82.8%～100.5%(bifenthrin),89.8%-101.7%(baythrioid),82.7%～99.4 %(fenvalerate),84.0%-100.3%(deltamethrin),80.0%-95.6%(fenpropathrin)and79.1%～101.0%(1 ambda-cyhalothrin), relative standard deviations were 3.6%-9.9%,6.8%-9.9%,6.0%-9.2%, 7.0%-9.4%,4.5%-9.5%,5.1%-8.8%,8.4%-9.7%.The extraction of seven pyrethroids in ginseng sample by ultrasonic solvent extraction was investigated. Ultrasonic solvent extraction was compared with ShakeTemp shaking. The extraction procedure was optimized with regard to packed column, extracted solvent, the rate of extracted solvent, the amount of eluant and duration of sonication. The preparation method for seven pyrethroids in ginseng sample was proposed. The recoveries of three standard addition levels of high, medium, low concentrations were 79.2%-100.0%(permethrin),81.5%-95.8% (bifenthrin),76.8%-101.7%(baythrioid),87.6%-97.7%(fenvalerate),83.5%-100.0%(deltamethri n),80.0%-101.3%(fenpropathrin) and 76.8%-99.4%(lambda-cyhalothrin), relativestandard deviations were 4.3%～10.7%,8.3%-9.9%,4.0%-10.1%,8.2%-10.1%,5.6%～9.7%,5.8%-9.7%, 4.0%-9.7%.