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

[目的]研究旨在优化苦瓜中氰霜唑(Cyazofamid)及其代谢物CCIM的QuEChERS-液相色谱-串联质谱残留分析方法;同时结合苦瓜的田间残留消解动态试验,对膳食摄入风险进行评价。[方法]苦瓜样品采用含1%乙酸的乙腈溶液提取,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试验,研究了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]试验结果表明：1)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,相关系数均大于0.9987;在0.010、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(RSD)为0.05%～12.1%。检出限(LOD)为0.364-0.654 μg/kg,方法定量限(LOQ)为添加的最低浓度0.010 mg/kg。2)田间试验结果表明：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。3)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。     

The dissipation of cyazofamid and its main metabolite CCIM during tomato growth and tomato paste making process

ABSTRACT

In several studies focused on the residues of cyazofamid and its main metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) on tomato where it is widely used, CCIM has been shown to have higher acute toxicity than cyazofamid, and this is crucial to evaluate the potential food risk of cyazofamid and CCIM. In this study, the dissipation of cyazofamid and CCIM during tomato growth and tomato paste making process were assessed. The targeted compounds cyazofamid and CCIM were determined by LC-MS/MS. The results indicated that the half-life of cyazofamid was 4.6 days after applying in the field, and the maximum value of CCIM was 0.08 mg/kg at 3 days after the last application of cyazofamid, then gradually decreased. In addition, the concentrations of cyazofamid and CCIM were affected by different processing steps including washing, peeling, homogenisation, simmering, and sterilisation. Results showed that the mean losses of cyazofamid and CCIM were 92.3% and 75.2% after washing and peeling. The Processing Factor (PF) values were all less than 1. Especially for peeling, the PFs of cyazofamid and CCIM were 0.12 and 0.04, respectively.