Study And Application On Analysis Techniques Of Pesticides Residues In Foodstuff

The analysis of pesticide residues in food which harm human health andinfluence environment safety- is one of the important research duties to chemical analysts. But the complexity of the determination system and ultratrace components have brought great difficulties to fast separation and accurate measurement for the task. At present, development of the fast, effective, sensitive multi-residue detection methods for pesticides residues analysis is the focus of study in the world.Tea is the main farm products with international competitive power.However, increasing concern over food safety and becoming a formal member of WTO are two drivers which make trade barrier and block the output. It is an important job for governments to build and perfect the test and monitoring system and relevant standards of pesticide residue analysis. Development of the fast, effective, sensitive mufti-residue detection methods of pesticides is a hot research task.Through the research on the effect of different extractive reagents and different extractive method in green tea,oolong , jasmine tea,we find out an optimal method for the extraction of pyrethroids in tea.For itssimple and low cost,the method could reduces pretreatment time and improve efficiency.Through the research on the effect of different purify SPE columns and different purify method in green tea,oolong , jasmine tea,choose GCB and PSA columns as purify method .Study different reagents to dilute analyt in green tea,oolong , jasmine tea,there is no apparent difference in teas.A multi-residue method was developed for rapid determination of 6 pyrethroids pesticides in tea by GC-MS. Pesticides were extracted from samples with acetone and MeCN, and the extract was cleaned up using SPE columns. Good linear and lower limits of detection were obtained.The linear range are between 2.00 mg/L～10μg/L, correlation coefficients are better than 0.98, and the detection limits is between 0.010～0.20mg/kg. All compounds have mean recoveries of 84.8%～115.9%之间and the relative standard deviation(RSD) values are between 3%～7%.This can satisfy the need of tea dectection in output.