Application Of QuEChERS In Pesticide Residue Analysis Of Traditional Chinese Medicine

Pesticide can effectively control pests and diseases in agriculture and make a great contribution to the harvest of crops. The wide or irrational use of pesticides has led to a big problem of pesticide residues. Pesticide residues not only damage human and animal health and environment safety, but also become the main reason for restricting China's agricultural exports. Therefore, it's significant to establish new methods for determination of multi-residue of pesticides in crops.Traditional Chinese medicine as one of the treasures of China, played an important role in disease prevention for thousands years. With the development of planting traditional Chinese medicine, many pesticides were used for disease prevention; as a result, traditional Chinese medicine pesticide residues were more and more serious. But standards of pesticide residue and regulations of maximum residue limits(MRL) about traditional Chinese medicine were few, so it was urgent to establish simple, fast and effective methods for the determination of pesticide residues. Qu ECh ERS method had been developed since2003, which has caused a lot of concerns and attentions. In recent years, a variety of analytical methods for pesticide residues determination based on Qu ECh ERS have been widely developed, and gradually applied to many fields of research. This research mainly reported applications of Qu ECh ERS in pesticides residue determination of traditional Chinese medicine. Angelica sinensis, Folium Isatidis and Safflower which stand for root,leaf and flower in traditional Chinese medicine, respectively, had been investigated by gas chromatography-mass spectrometry. The analytical methods for pesticide residue determination had been established and good results had been obtained. The methods had been successfully applied to the determination of real samples.The Qu ECh ERS combined with gas chromatography-mass spectrometry for determination of nine herbicides residue in Angelica sinensis has been developed. Theexperimental parameters, such as type and volume of extraction solvent, ultrasonic time,type and amount of cleaning agent influencing the efficiency of extraction and purification had been investigated systematically. Finally, the optimum conditions had been found.Each pesticide's effect matrix was evaluated by matrix matching method and accuracy and precision of the method had been verified. Under optimal conditions, the nine herbicides showed a good linearity within a range of 0.01~5.0 mg/L, the limits of detection(LODs)were in the range between 0.52 and 6.6 ?g/kg and all the herbicides showed weak matrix effect. The recoveries of nine herbicides over the two spiked concentration levels in Angelica sinensis were between 74.58% and 96.37% with the relative standard deviations(RSD) less than 11.73%, meeting the requirements of pesticide residue analysis. This method was used for detecting herbicides residue in random Angelica sinensis samples purchased from pharmacies and no herbicides were detected.A method for determination of six organophosphorus pesticides in Folium Isatidis by Qu ECh ERS and gas chromatography-mass spectrometery had been developed. The experimental parameters, such as type and volume of extraction solvent, ultrasonic time,type and amount of cleaning agent, affecting the extraction and purification efficiency had been investigated systematically. And finally, the optimum conditions had been found.Each pesticide's effect matrix was evaluated by matrix matching method and accuracy and precision of the method had been verified. Under optimal conditions, the six organophosphorus pesticides showed a good linearity within a range of 0.01~5.0 mg/L and the LODs were in the range between 1.9 and 22.2 ?g/kg. Among them, ethoprophos,parathion and malathion showed moderate matrix effects, methidathion, chlorpyrifos and chlorpyrifos-methyl showed weak matrix effect. The recoveries of six organophosphorus pesticides in Folium Isatidis sample were between 77.83~99.30% and RSDs were lower than 8.57%, meeting the requirements for pesticide residue analysis. This method was used for detecting herbicides residue in random Folium Isatidis samples purchased from pharmacies, it turned out that chlorpyrifos was detected in two samples and ethoprophos in one sample.A method was established for detecting six fungicides in Safflower by Qu ECh ERS and gas chromatography-mass spectrometery. The experimental parameters, such as typeand volume of extraction solvent, ultrasonic time, type and amount of cleaning agent which affected extraction and purification efficiency had been investigated systematically. And finally, the optimum conditions had been found. Each pesticide's effect matrix was evaluated by matrix matching method and accuracy and precision of the method had been verified. Under optimal conditions, six fungicides in Safflower showed a good linearity within a range of 0.01~5.0 mg/L and LODs were in the range between 0.30 and 10.1 ?g/kg.Among them, metalaxyl showed a strong matrix effect, propiconazole, pyrimethanil and diniconazole showed moderate matrix effects, and hexaconazole and tebuconazole showed weak matrix effect. The mean recoveries of six fungicides in Safflower samples were79.52~96.39% and the RSDs were less than 9.22%. This method can be used to analyze the six fungicides in real samples, and among the selected 10 samples, metalaxyl was detected in one sample and tebuconazole in one sample.