12%精喹禾灵·乙羧氟草醚·甲咪唑烟酸微乳剂在花生中的残留行为评价

Evaluation of residual behavior of quizalofop-P-ethyl·fluoroglycofen-ethyl·imazapic 12%micro-emulsion in peanut

[目的]建立同时检测花生中乙羧氟草醚、甲咪唑烟酸、喹禾灵及其代谢物的分析方法,并评价农药残留安全性。[方法]样品经酸化乙腈提取,以优化QuEChERS方法净化,采用超高效液相色谱串联质谱仪,多反应监测模式测定,基质匹配外标法定量。[结果]乙羧氟草醚、甲咪唑烟酸、喹禾灵和喹禾灵酸的定量限在0.01~0.05 mg/kg之间;在0.01~1 mg/kg的添加质量分数范围内,各农药的添加回收率在80%~94%之间,且相对标准偏差均低于10%。在0.001~1.5 mg/L的质量浓度范围内,乙羧氟草醚、甲咪唑烟酸、喹禾灵和喹禾灵酸的线性相关性良好,相关系数均大于0.99。12%精喹禾灵·乙羧氟草醚·甲咪唑烟酸微乳剂,以180 g a.i/hm2于花生苗后早期用药1次,成熟期花生中各农药的残留量均低于其定量限,风险商(RQ)小于1。[结论]该方法操作简单、高效、稳定性好,可同时快速检测花生中多种农药的残留量,通过规范残留试验中值计算可知,各农药膳食风险均不会对一般人群健康产生不可接受的风险。

[Aims]Establishing a method for simultaneous determination of fluoroglycofen-ethyl,imazapic,quizalofop-ethyl and its metabolite in peanut,and evaluating the safety of pesticide residues.[Methods]The samples were extracted by acidic acetonitrile,purified by optimized QuEChERS,and determined by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),using multiple reaction monitoring(MRM)mode by matrix-matched external standard method.[Results]The limits of quantitation(LOQ)of fluoroglycofen-ethyl,imazapic,quizalofop-ethyl and quizalofop free acid were betweet 0.01 to 0.05 mg/kg.At spiked levels of 0.01-1 mg/kg,the recoveries of all pesticides were from 80%to 94%,and the relative standard deviations(RSDs)were lower than 10%.At the range of 0.001-1.5 mg/L,the correlation coefficients of fluoroglycofen-ethyl,imazapic,quizalofop-ethyl and quizalofop free acid were bigger than 0.99.When quizalofop-P-ethyl·fluoroglycofen-ethyl·imazapic 12%micro-emulsion was sprayed once at 180 g a.i./ha during the early post-emergence period of peanut,the residues of all pesticides in mature peanuts were all lower than limits of quantification,with the risk quotients(RQ)less than 1.[Conclusions]The method which is simple,efficient and stable can detect simultaneously and rapidly the residues of herbicides in peanut.According to the calculation of Standard Residue Test Median(STMR),the dietary risk of each pesticide will not cause unacceptable risk to the health of the general population.