氟吡菌胺和喹啉铜在黄瓜中的残留行为及膳食风险评估

Residue behavior and dietary risk assessment of fluopicolide and oxine-copper in cucumber

[目的]明确氟吡菌胺和喹啉铜在黄瓜上的残留行为,评估施用后可能产生的膳食暴露风险。[方法]在黑龙江、山东省等12地进行了田间残留试验,研究了2种农药在黄瓜上的残留和消解动态。利用气相色谱-质谱联用仪(GC-MS)和超高效液相色谱-质谱联用仪(UPLC-MS/MS)进行样品中氟吡菌胺及代谢物(2,6-二氯苯甲酰胺)和喹啉铜定量分析。[结果]氟吡菌胺和喹啉铜在黄瓜中的消解符合一级反应动力学模型的规律,半衰期为2.38~5.92、2.04~3.09 d;试验过程中2,6-二氯苯甲酰胺残留量均<LOQ。最终残留试验结果显示,药后3 d黄瓜中的氟吡菌胺和喹啉铜残留中值(STMR)分别为0.061、0.056 mg/kg,药后5 d的残留中值(STMR)分别为<LOQ和0.036 mg/kg,均低于我国规定的MRL值。基于我国居民膳食结构的风险评估结果显示:氟吡菌胺和喹啉铜的风险概率分别为1.05%和2.84%,RQ低于100%为可接受水平;不同年龄段人群的慢性膳食风险评估显示采收间隔时间为3 d时,氟吡菌胺和喹啉铜膳食风险概率为0.25%~0.33%和0.22%~0.30%,5 d时膳食风险概率为0.11%~0.15%和0.13%~0.18%,均为可接受风险水平。[结论]基于本次残留规范试验,在良好农业操作规范标签推荐的方式下,32%氟吡菌胺·喹啉铜悬浮剂以不高于278.4 g a.i./hm2剂量在黄瓜上均匀喷施叶片使用,施药3次,施药间隔5 d,安全间隔期为3 d,收获期的黄瓜是安全的。

[Aims]This study aims to evaluate the residue behavior and dietary exposure risk of fluopicolide and oxine-copper applied to cucumber.[Methods]The residue and dissipation dynamics of fluopicolide and oxine-copper in cucumber were studied through filed experiments carried out in 12 provinces in China including Heilongjiang,Shandong and the dietary intake risk of fluopicolide and oxine-copper was assessed.The samples were quantitatively analyzed by gas chromatography-mass spectrometer(GC-MS)and ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).[Results]The results showed that the degradation of fluopicolide and oxine-copper in cucumber conformed to the first-order kinetic equation,and the half-lives were 2.38-5.92 and 2.04-3.09 d respectively.During the test,the residues of 2,6-dichlorobenzamide were all<LOQ.On day 3 after application,the Supervised Trials Median Residues(STMR)of fluopicolide and oxine-copper in cucumber were 0.061 and 0.056 mg/kg.On day 5 after application,the STMR were<LOQ and 0.036 mg/kg,which were lower than the maximum residue limits(MRLs)provided by China.The risk assessment results based on the dietary structure of Chinese residents show that the risk probability of fluopicolide and oxine-copper is 1.05%and 2.84%respectively,and RQ below 100%is an acceptable level.Chronic dietary risk assessment of people of different ages showed that the dietary risk probability of fluopicolide and oxine-copper was 0.25%-0.33%and 0.22%-0.30%when applied 3 d before harvest,and 0.11%-0.15%and 0.13%-0.18%when applied 5 d before harvest,all of which were extremely low risk levels.[Conclusions]The application of fluopicolide·oxine-copper 32%dispersible concentrate in cucumber is carried out 3 times,and the effective dose is not more than 278.4 g a.i./ha,the application interval is 5 d,3 d was selected as the post-harvest interval,the application of fluopicolide and oxine-copper on cucumber trees is safe under label use at good agricultural practices.