Research Of The Method Of Detection And Removal Of Common Pesticide Residues In The Four Chinese Herbal Medicines

Owning has the most abundant resource of traditional Chinese herbal medicines.However,Chinese import and export trade of these medical materials is often hampered due to the issues of pesticide residues.Consequently,setting up a method of detecting the pesticide residues are of great significance to detecting and monitoring pesticide residues in traditional Chinese medical materials.This paper was conducted in dandelion,honeysuckle,ginseng and wolfberry by using Qu ECh ERS combined with ultra-high performance liquid chromatography-tandem mass spectrometry.By applying this technique,a new method of detecting fourteen kinds of pesticide residues can be established.In this paper,we also discuss products and mechanism of degradation of fipronil and carbendazim contained in the four traditional Chinese medical materials.Conducting our experiments on Chinese wolfberry,the owner of the highest rate of pesticides among the four initial Chinese traditional medicine,what effect will bring to the removal rates of fipronil,imidacloprid,acetamiprid and carbendazim has been figured out as we adopted different processing methods.The main contents of this paper are as followed.1.The Qu ECh ERS combined with UPLC-MS/MS method was established for determination of 14 common pesticide residues in four kinds of Chinese traditional medicinal materials,including dandelion,honeysuckle,wolfberry and ginseng.With correlation coefficient greater than 0.99,the 14 pesticides showed great linear relationship within their respective linear range.The detection limit was between0.05-0.5 ng/m L while the quantitation limit was between 0.1-1.0 ng/m L.Additionally,the spiked recoveries were between 78.58 %-107.24 % at three spiked levels while the relative standard deviations(RSD)were between 1.28%-11.20%.2.The m/z of three kinds of degradation of fipronil examined by UPLC-MS were419,451 and 387.The degradation mechanism of four pesticides was discussed.Besides,Qu ECh ERS-UPLC-MS/MS method was established to detect residues of the four pesticides in dandelion,honeysuckle,wolfberry and ginseng.With correlation coefficient greater than 0.99,the four pesticides showed great linear relationship within their respective linear range.The detection limit was between 0.05-0.25 ng/m L while the quantitation limit was between 0.1-0.5 ng/m L.Additionally,the spiked recoveries were between 82.85%-102.76% at three spiked levels while the relative standard deviations(RSD)were between 1.84%-7.45%.3.The m/z of two kinds of degradation of carbendazim examined by UPLC-MS were 134 and 119.The degradation mechanism of these three pesticides was discussed.Besides,Qu ECh ERS-UPLC-MS/MS method was established to detect residues of the three pesticides in dandelion,honeysuckle,wolfberry and ginseng.With correlation coefficient greater than 0.99,the four pesticides showed great linear relationship within their respective linear range.The detection limit was between 0.05-0.1 ng/m L while the quantitation limit was between 0.1-0.25 ng/m L.Additionally,the spiked recoveries were between 78.80%-102.36% at three spiked levels while the relative standard deviations(RSD)were between 1.82%-7.85%.4.The removal rates of fipronil,imidacloprid,acetamiprid and carbendazim in Chinese wolfberry were examined after treating the samples of Chinese wolfberry by heating,washing,processing and illumination.Under heating condition,the removal rates of four pesticide residues increased as temperature increased.Carbendazim and fipronil reached the highest values at 70℃.After washing,the removal rate of carbendazim peaked when it was treated with 0.5% H2O2.The removal rate of fipronil was the highest under ultrasonic condition.The removal rate of imidacloprid and acetamiprid was the highest under hot water condition.Among the processing methods,carbendazim and fipronil reached the peak of their removal rates under the processing of 70% ethanol.The removal rate of imidacloprid and acetamiprid was the highest under the condition of salt frying.In the illumination method,the removal rates of all these four pesticide residues were the highest under sunlight irradiation.According to the effect of processing method,the removal rate of carbendazim by processing method was the highest while the removal rates of fiphronil and imidacloprid using heating method were the highest.As for acetamiprid,the removal rate reached the highest point under illumination.