田间条件下玉米中甲氨基阿维菌素苯甲酸盐和吡丙醚的残留水平与膳食风险评估

Residue levels and dietary risk assessment of emamectin benzoate and pyriproxyfen in corn under field conditions

[目的]本文旨在研究甲氨基阿维菌素苯甲酸盐和吡丙醚在田间玉米中的残留行为并进行了慢性膳食风险评估,为甲氨基阿维菌素苯甲酸盐和吡丙醚在玉米上的合理使用提供建议。[方法]按照良好农业规范(good agricultural practices,GAP),在中国12地玉米主产区开展12%甲氨基阿维菌素苯甲酸盐·吡丙醚微乳剂(3%甲氨基阿维菌素苯甲酸盐+9%吡丙醚)在玉米上的残留田间试验,在玉米螟卵孵化盛期,以45 g·hm^(-2)的剂量喷施该制剂1次,推荐安全间隔期(pre-harvest interval,PHI)为21 d。同时基于QuEChERS和高效液相色谱串联质谱(HPLC-MS/MS)法建立了在玉米中测定甲氨基阿维菌素苯甲酸盐和吡丙醚的残留分析方法,应用该方法检测了这2种化合物在田间玉米样品中的残留量,并根据田间试验结果评估其慢性膳食风险。[结果]在0.01、0.05、0.1和1 mg·kg^(-1)添加水平下,甲氨基阿维菌素B1a和吡丙醚在鲜食玉米、玉米籽粒和玉米秸秆样品中的平均回收率为87%~106%,相对标准偏差(RSD)为2.3%~7.5%,定量限(limits of quantification,LOQ)均为0.01 mg·kg^(-1);施药后21和28 d收获的鲜食玉米和玉米籽粒样品中,甲氨基阿维菌素苯甲酸盐B1a的最终残留量均小于0.011 mg·kg^(-1),均未超出中国制定的甲氨基阿维菌素苯甲酸盐在玉米上的最大残留限量(maximum residue limit,MRL)(鲜食玉米:0.05 mg·kg^(-1);玉米籽粒:0.05 mg·kg^(-1));吡丙醚的最终残留量均小于0.01 mg·kg^(-1)(目前中国未制定吡丙醚在玉米上的MRL)。甲氨基阿维菌素苯甲酸盐和吡丙醚的慢性风险商分别为78.4%和5.8%,均低于100%,表明对消费者造成的健康风险较低。[结论]按照GAP条件在玉米上施用12%甲氨基阿维菌素苯甲酸盐·吡丙醚微乳剂,推荐的PHI为21 d是安全的。研究结果可为我国制定吡丙醚在玉米中的MRL提供参考。

[Objectives]This paper aimed to research on the residue behavior of emamectin benzoate and pyriproxyfen in field corn and evaluate the chronic dietary risk,so as to provide suggestions for the rational use of emamectin benzoate and pyriproxyfen on corn.[Methods]In accordance with good agricultural practices(GAP),the field trials of 12%microemulsion(3%emamectin benzoate+9%pyriproxyfen,ME)on corn were carried out across 12 regions of main corn production in China.The formulation of 12%ME was sprayed once at the dosage of 45 g·hm^(-2) during the incubation period of corn borer eggs,and the recommended pre-harvest interval(PHI)was 21 days.Meanwhile,a method for determination of emamectin benzoate and pyriproxyfen in corn was developed based on QuEChERS and high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS),which was applied to detect the residue levels in field corn samples,and the chronic dietary risk was assessed based on field trial results.[Results]At the spiked levels of 0.01,0.05,0.1 and 1 mg·kg^(-1),the mean recoveries of emamectin B1a and pyriproxyfen in fresh corn,corn kernels and corn straw samples were 87%-106%,with relative standard deviations(RSD)of 2.3%-7.5%and limits of quantification(LOQ)all being 0.01 mg·kg^(-1).In the fresh corn and corn kernel samples harvested at 21 and 28 days after application,the terminal residue levels of emamectin B1a benzoate were less than 0.011 mg·kg^(-1),which were lower than the maximum residue limit(MRL)of emamectin benzoate in corn in China(fresh corn:0.05 mg·kg^(-1);corn kernel:0.05 mg·kg^(-1)),and the terminal residue levels of pyriproxyfen were less than 0.01 mg·kg^(-1)(At present,the MRL of pyriproxyfen on corn had not been set in China).The chronic risk quotients of emamectin benzoate and pyriproxyfen were 78.4%and 5.8%,respectively,which were both lower than 100%,indicating a low risk to consumers’health.[Conclusions]Under the GAP conditions of applying 12%microemulsion(3%emamectin benzoate+9%pyriproxyfen)on corn,the recommended PHI of 21 days was safe.The paper could also offer a reference for China to formulate the MRL of pyriproxyfen on corn.