氰霜唑及其代谢物4-氯-5-(4-甲苯基)-1H-咪唑-2-腈在苦瓜中的残留消解动态及膳食安全性评价

Residual degradation dynamics and dietary safety assessment of cyazofamid and its metabolite(4-chloro-5-(4-tolyl)-1 H-imidazole-2-carbonitrile in balsam pear

中文关键词:  氰霜唑  4-氯-5-(4-甲苯基)-1H-咪唑-2-腈  代谢物  苦瓜  残留  风险评估

英文关键词:cyazofamid  4-chloro-5-(4-tolyl)-1H-imidazole-2-carbonitrile  metabolite  balsam pear  residues  risk assessment

中文摘要:

      目的 优化苦瓜中氰霜唑(cyazofamid)及其代谢物4-氯-5-(4-甲苯基)-1H-咪唑-2-腈(4-chloro-5-(4-tolyl)-1h-imidazole-2-carbonitrile, CCIM)的QuEChERS-液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry, LC-MS/MS)分析方法, 并结合苦瓜的田间残留消解动态实验, 对膳食摄入风险进行评价。方法 采用含1%乙酸的乙腈溶液提取苦瓜样品, LC-MS/MS进行检测, 通过基质匹配标准溶液外标法定量。通过在黑龙江、河北、河南、重庆、浙江和广东6地进行了100 g/L氰霜唑悬浮剂在苦瓜上残留的田间实验, 研究氰霜唑在苦瓜中的消解动态, 对苦瓜中氰霜唑可能产生的膳食摄入风险安全进行评价。结果 氰霜唑在0.005~1.0 mg/L、CCIM在0.001~1.0 mg/L质量浓度范围内线性关系良好, 相关系数均不小于0.9987; 方法检出限为0.364~0.654 μg/kg, 方法定量限为添加的最低浓度0.010 mg/kg; 在0.01、0.10、0.50 mg/kg 3个浓度下, 苦瓜中氰霜唑及CCIM的回收率为80.0%～100.0%, 相对标准偏差为0.05%～12.1%。氰霜唑在苦瓜中消解符合一级反应动力学方程, 半衰期为3.0～4.9 d, 属易降解农药; 使用100 g/L氰霜唑悬浮剂, 施药剂量105-157.5 g a.i./hm2, 分别施药2、3次, 苦瓜中氰霜唑总的最终残留量最大值为6.54 mg/kg; 膳食摄入风险评估结果表明: 氰霜唑的风险概率为每人每日摄入总量的1.0%。结论 在苦瓜生长期间按照推荐剂量合理使用氰霜唑对消费者的膳食健康风险极低, 对消费者健康是安全的。

英文摘要:

      Objective To optimize the QuEChERS liquid chromatography tandem mass spectrometry (LC- MS/MS) method for the determination of cyazofamid and its metabolite 4-chloro-5-(4-tolyl) -1H-imidazole- 2-carbonitrile (CCIM), and to evaluate the risk of dietary intake based on the field residue digestion dynamic experiment of balsam pear. Methods Balsam pear samples were extracted with acetonitrile solution containing 1% acetic acid, detected by LC-MS/MS, and quantified by matrix matching standard solution external standard method. Field experiments were conducted in Heilongjiang, Hebei, Henan, Chongqing, Zhejiang and Guangdong provinces to study the degradation dynamics of fenoxazole in balsam pear, and to evaluate the potential dietary intake risk and safety of fenoxazole in balsam pear. Results The linear range of fenoxazole was 0.005?1.0 mg/L, CCIM was 0.001?1.0 mg/L, the correlation coefficients was greater than 0.9987, the limit of detection was 0.364?0.654 μg/kg, the limit of quantitation was 0.010 mg/kg. The recoveries of fenoxazole and CCIM in balsam pear were 80.0%?100.0% and the relative standard deviations were 0.05%?12.1% at 3 concentration levels of 0.01, 0.10 and 0.50 mg/kg. The degradation of fenoxazole in balsam pear accorded with the first-order reaction kinetic equation, and the half-life was 3.0?4.9 d, which was a kind of easily degradable pesticide. The maximum final residue of fenoxazole in balsam pear was 6.54 mg/kg when 100 g/L fenoxazole suspending agent was applied at the dosage of 105?157.5 g a.i./hm2 respectively for 2 and 3 times. The results of dietary intake risk assessment showed that the risk probability of fenoxazole was 1.0% of the total daily intake per person. Conclusion The reasonable use of fenoxazole at the recommended dose during the growth of balsam pear has very low dietary health risk and is safe for consumers.