Determination Of Pesticide Residues In Chinese Herbal Medicine By LC-MS/MS

With the development of social economy and people’s living standards, people pay moreand more attention to the harm that pesticide residues do on health and environment. It hasbecome an important indicator to measure the quality and safety of food, medicine and so on.More and more countries and regions in the world have established maximum residue limitson pesticides, which are increasingly stringent.Chinese herbal medicine has a history of thousands of years, and it is the treasure ofChinese culture. In order to improve the controlling effect and to suppress the resistance ofpesticides, people use a variety of pesticides and even abuse them indiscriminately in theproductive process of Chinese herbal medicine. It seriously impacts on the quality of Chinesemedicine material, which not only brings potential risks to people’s health but also directlyresults in export block of herb. Chinese herbal ingredients are complex, of which manycomponents have similar chemical structure, physical and chemical nature with pesticides,and pesticide residues in Chinese herbal medicine are mostly at trace or ultra-trace level. Sofor pesticide residues in Chinese herbal medicines, some higher requirements for detectionmethods need to be developed.In this experimental study, we optimized the extraction solvent, extraction method, cleaning upmethod and so on, then established a preparation method to detect171pesticide residues in Chineseherbal medicine based on LC-MS/MS, and this article’s main conclusions are as follows:In this method, the samples were extracted with acetonitrile/water in the presence ofsodium acetate and anhydrous magnesium sulfate, and then the supernatant was transferred tothe SPE (Cleanert TPH) cartridge using acetonitrile/toluene (8:1, V/V) as eluting solution forpurification. The LOD (S/N=3) and LOQ (S/N=10) of all pesticides were in the range of0.35~40.00μg/kg and1.00~120.00μg/kg respectively, lower than the MRL drafted by EU,Japan, United States and other countries and regions. Among171targeted pesticides, thelinear correlation coefficients of153~164pesticides (89.50%~96.00%of all pesticides)were not less than0.9950in the corresponding ranges of concentration. The range of spikedrecoveries at three levels of high (3MRL), middle (MRL) and low (LOQ) was from60%to120%for148to160pesticides (86.55%~93.57%of all pesticides, with the relative standarddeviation (RSD) less than20%. The method is simple, rapid, and the sensitivity and precisionare well enough to meet the requirements for the detection of multiple pesticide residues ofChinese herbal medicine at trace level.