乙嘧酚在冬瓜上的残留行为及膳食风险评估

目的研究乙嘧酚在冬瓜上的残留行为,对膳食摄入风险进行评价。方法冬瓜样品经乙腈提取, N-丙基乙二胺(primary secondary amine, PSA)净化,液相色谱-串联质谱法进行检测,通过基质匹配标准溶液外标法定量。2018年在山东、福建、安徽、广西、四川和北京6地进行乙嘧酚在冬瓜上的规范残留试验,获取乙嘧酚在冬瓜上的残留试验中值,进行膳食摄入风险评估。结果在添加水平为0.01、0.08、0.5mg/kg时,乙嘧酚在冬瓜上的平均回收率为85.2%~92.0%,相对标准偏差为2.5%~5.1%(n=5),定量限为0.01 mg/kg。乙嘧酚在冬瓜中的消解符合一级动力学方程,半衰期为4.1~4.8 d。采用25%乙嘧酚悬浮剂按有效成分375和562.5 g a.i./hm^2剂量施药3~4次,于末次施药后5、7和14 d采样测定,冬瓜中乙嘧酚的残留量为<0.01~0.35 mg/kg。膳食风险评估结果表明:一般人群对乙嘧酚的国家估算每日摄入量(nationalestimateddailyintake,NEDI)为0.0189 mg,膳食摄入风险概率(risk quotient, RQ)为0.86%。结论乙嘧酚在冬瓜中的残留对消费者不会产生不可接受的风险。

Residue behavior and dietary risk assessment of ethirimol in wax gourd

Objective To study the residue behavior of ethirimol in wax gourd, and then evaluate the risk of dietary intake. The method for the determination of ethirimol in wax gourd with liquid chromatography-tandem mass spectrometry was established. Methods The residue of ethirimol in wax gourd was extracted with acetonitrile, purified with primary secondary amine (PSA), detected by liquid chromatography-tandem mass spectrometry, and quantified by matrix matching standard solution external standard method. Supervised field trials of ethirimol in wax gourd were conducted in Shandong, Fujian, Anhui, Guangxi, Sichuan and Beijing provinces in 2018. The STMR of ethirimol in wax gourd was acquired, and then the risk assessment of dietary intake was conducted. Results The recovery of ethirimol in wax gourd ranged from 85.2% to 92.0% with the RSDs of 2.5%-5.1% (n=5) at the spiked level of 0.01, 0.08 and 0.5 mg/kg. The limit of quantitation (LOQ) of ethirimol was 0.01 mg/kg. The dissipation of ethirimol in wax gourd fitted to the first order kinetics with the half-life of 4.1- 4.8 d. The 25% suspension concentrate of ethirimol was sprayed at 375 and 562.5 g a.i./hm2 for 3-4 times on wax gourd, and then the samples were taken and determined at 5, 7 and 14 d after the last application. Results showed that the residues of ethirimol in wax gourd were less than0.01-0.35 mg/kg. The result of the dietary risk assessment revealed that the national estimated daily intake (NEDI) of ethirimol was 0.0189 mg with the risk quotient (RQ) of 0.86% for general population. Conclusion The terminal residue of ethirimol in wax gourd will not cause unacceptable risk to the health of the consumers.