噻虫啉在水稻中的残留消解动态及风险评估

Residue dynamics and risk assessment of thiacloprid in rice

为了评价19.8%噻虫啉悬浮剂在水稻上使用的安全性,于2011—2012年在福州、天津和南京三地进行了为期2年的田间试验,采用超高效液相色谱法(UPLC)研究了噻虫啉在水稻秆、稻米和稻壳中的消解动态和最终残留.结果表明:噻虫啉在水稻植株中的消解规律符合一级动力学模型,在三地的半衰期为3.8~17.3 d.在推荐使用剂量86.4 g·hm-2(以有效成分计)下,距最后一次施药30 d后收获的稻米中噻虫啉的残留量未超过日本规定的最大残留限量(MRL)值(0.1 mg·kg-1).通过计算得出每人每天从稻米中所摄入的噻虫啉为0.121 mg,风险商值(RQ)为0.192,处于安全水平.

In order to evaluate the safety and regular use of thiacloprid 19. 8% suspension concentrate( SC),the final residue and residue dynamic of thiacloprid in rice straw,rice shell and brown rice were investigated and the samples were analyzed by ultra performance liquid chromatography( UPLC)in Fuzhou,Tianjin and Nanjin City. The results indicated that the decline curves of thiacloprid in wheat plant fit the first-order kinetics. The dissipation experiments showed thehalf-lives( T1 /2) of thiacloprid in plants ranged3.8 ~ 17.3 days in three cities. The terminal residue indicated that when the rice plant was sprayed with hiacloprid 19. 8% SC with the recommended dosage of 86. 4 g·hm-2( active ingredients) and the last application was done 30 d after harvesting,thiacloprid residue in rice were lower than the MRL of Japan: 0. 1 mg·kg-1. The intakes of thiacloprid per person-day from rice was calculated as 0. 121 mg. Risk quotient( RQ) was 0. 192,showing the residue could be declined to the safety level.