Study On Dissipation Of Acetamiprid And Profenofos In Cabbage And Soil

In the dissertation, the residue behm2viors of acetamiprid and profenofos in cabbage and soil were investigated. It is helpful to provide the basis for making the MRL of acetamiprid and profenofos in cabbage and providing data to pesticide register, and to give a guidance for the safety and reasonable use of6.5%Lambda-cyhm2lothrin. acetamiprid EC and40%profenofos EC to make sure thm2t it was safe to the human being and agricultural environment.The analytical methods were developed to determine the acetamiprid in cabbage and soil. Pesticides were extracted from samples with acetonitrile and the extract was cleaned up using Florisil disposable cartridges with15mL of hexane:acetone (50:50V/V) for elution. The eluent was concentrated to near dryness. The residue was reconstituted in1.0mL of acetone and determined by Gas Chromatography with Electron Capture Detector (GC-ECD). The fortified recovery in cabbage and soil was investigated at the level of0.01,0.05and0.1mg/kg, showed mean average value ranged from92%-96%in cabbage and78%-88%in soil, with the relative standard deviations (RSDs) ranged from6.0%-7.2%in cabbage and2.2-3.9%in soil.A reliable method for analysis of profenofos in cabbage and soil was investigated by GC-FPD. Pesticides were extracted from samples with acetonitrile and concentrated and dissolved in1.0mL of acetonitrile. When blank cabbage and soil spiked at0.01,0.1and1.0mg/kg, the average recoveries and RSDs in cabbage and soil were90～99%,94～98%and4.8-6.7%,4.7-8.6%, respectively. The result proved thm2t sensitivity and accuracy of analytical method met requirement of pesticide residue detection.The results suggested thm2t the dissipation of acetamiprid (1.5times of the recommended dosage) and profenofos (2times of the recommended dosage) in cabbage and soil in Shm2ndong, Beijing and Hunan appeared to follow the first-order kinetic reaction. The residue dissipated with hm21f-life of acetamiprid and profenofos were less thm2n10days in cabbage and soil. From the results of final residues in supervised field trials in Shm2ndong, Beijing and Hunan, it was found thm2t residue of acetamiprid in cabbage after7days of last application was0.034mg/kg; residue of profenofos in cabbage after21days of last application was0.40mg/kg. The terminal residues of acetamiprid and profenofos in cabbage were blow0.5mg/kg, which is the MRL level set by China (NY1500-2007) Therefore, pre-hm2rvest interval (PHI) of7days (acetamiprid) and21days (profenofos) in cabbage between last application and hm2rvest were recommended.