吡虫啉在三种芸薹属蔬菜中的残留行为及风险评估

Study on Residue Behavior and Risk Assessment of Imidacloprid in Three Brassica Vegetables

建立了分析菜薹、芥蓝和青花菜中吡虫啉残留量的方法。样品经乙腈震荡提取,盐析后取乙腈相浓缩,PSA和GCB分散固相萃取净化后,高效液相色谱-串联质谱法检测。吡虫啉在3种蔬菜中的平均回收率分别为82.2%~99.7%、92.9%~108.3%和80.3%~100.5%,相对标准偏差分别为2.5%~6.0%、0.6%~3.1%和1.9%~2.8%,定量限均为0.02mg/kg。在黑龙江省、江苏省和湖南省进行田间试验,按照20%吡虫啉可溶液剂的推荐施药方法施药,末次施药5、7、10d后,菜薹中吡虫啉的残留量为<0.02~0.080mg/kg,芥蓝中吡虫啉的残留量为<0.02~0.11mg/kg,青花菜中吡虫啉的残留量为<0.02~0.33mg/kg。经长期膳食摄入风险评估,我国普通人群吡虫啉的日摄入风险概率最大为11.7%,建议制定吡虫啉在菜薹、芥蓝和青花菜中的最大残留限量分别为0.5mg/kg、1.0mg/kg和1.0mg/kg。

A method of determination of imidacloprid residue in brassica parachinensis bailey,brassica alboglabra bailey and broccoli was developed.The samples were extracted with acetonitrile and determined by HPLC-MS/MS after being concentrated and cleaned up by dispersive solid phase extraction with PSA and GCB.The recoveries of imidacloprid in brassica parachinensis bailey,brassica alboglabra bailey and broccoli,plant and soil were 82.2%~99.7%,92.9%~108.3%,80.3%~100.5%and 81.5%~99.1%,with the relative standard deviations of 2.5%~6.0%,0.6%~3.1%and 1.9%~2.8%,respectively.The minimum detectable concentrations were all 0.02 mg/kg in the three varieties of vegetable.The field trials were carried out in Heilongjiang,Jiangsu and Hunan province.Imidacloprid 20%soluble concentrate were sprayed at the recommended doses,and the samples were collected after 5,7,10 days of the last spraying.The terminal residues of imidacloprid in brassica parachinensis bailey were<0.02~0.080 mg/kg,<0.02~0.11 mg/kg in brassica alboglabra bailey,and<0.02~0.33 mg/kg in broccoli.After long-term dietary intake risk assessment,the daily risk probability in the general population was 11.7%at most.Therefore,it is suggested that the maximum residue limits of imidacloprid in brassica parachinensis bailey,brassica alboglabra bailey and broccoli should be 0.5 mg/kg,1.0 mg/kg and 1.0 mg/kg,respectively.