Residue dissipation dynamics and dietary risk assessment of 6 pesticides in snow pea
[Aims]To investigate the dynamics of residual dissipation of pyraclostrobin,beta-cypermethrin,acetamiprid,difenoconazole,azoxystrobin and thiamethoxam on snow pea and to evaluate the dietary risk of them.[Methods]Field residue tests of 6 pesticides on snow pea were carried out by spray method.The residue amount on snow pea was determined by QuEChERS pretreatment combined with GC-MS/MS analysis method,and the dietary risk assessment was conducted.[Results]The recoveries of 6 pesticides were 72.3％-108.4％,and RSD was 1.7％-9.3％.The mass concentration had a good linear relationship with its peak area in the range of 0.005-0.5 mg/L.The dissipation half-lives of pyraclostrobin,beta-cypermethrin,acetamiprid,difenoconazole,azoxystrobin and thiamethoxam were 2.2-2.7,2.2-2.7,3.0-3.7,0.9-3.1,1.1-3.1,0.8-2.4 d respectively,which indicated that they were easily degradable pesticides.Dietary risk assessment showed that the acute and chronic dietary risk values of different age groups of consumers were lower than 100％,which was in an acceptable safe level.[Conclusions]It is recommended to spray beta-cypermethrin 4.5％EC,acetamiprid 5％EC,azoxystrobin 30％SC and thiamethoxam 25％WG on snow pea according to 600,450,450 mL/ha and 120 g/ha,respectively.The preharvest interval of the four pesticides can be set to 1 d.When the planting process is strictly in accordance with the production operation rules,the application dose is controlled and the preharvest interval of pesticide is observed,there will be no effect on the health of the population.Pyraclostrobin 25％SC should be sprayed at 600 mL/ha and difenoconazole 10％ME should be sprayed at 1499 g/ha,with the preharvest interval of 10 and 3 d respectively.They are not suitable to be use during the flowering and pod forming periods.
万方数据
维普
