液相色谱-串联质谱法检测吲唑磺菌胺在烟叶中的残留及消解动态

Residue and dissipation of amisulbrom in tobacco leaves by liquid chromatography-tandem mass spectrometry

为研究吲唑磺菌胺在烟草中的残留消解特征,建立了采用Qu ECh ERS前处理与液相色谱-串联质谱(LC-MS/MS)检测相结合的烟叶中吲唑磺菌胺残留量的分析方法。样品经乙腈提取,N-丙基乙二胺(PSA)吸附剂净化,液相色谱-串联三重四级杆质谱法检测,外标法定量。结果表明:在0.01、0.1和10 mg/kg 3个添加水平下,吲唑磺菌胺在鲜烟叶和干烟叶中的平均回收率分别为88%~93%和93%~107%,相对标准偏差(RSD)分别为2.5%~13.9%和6.7%~7.4%,定量限(LOQ)分别为0.01和0.02 mg/kg。利用该方法分别于2013年和2014年检测了山东和四川烟叶中吲唑磺菌胺的残留消解动态和最终残留量。结果表明:吲唑磺菌胺在烟叶中的半衰期为5.1~9.8 d;按照有效成分105和157.5 g/hm2的剂量,分别施药3次和4次,距末次施药14 d后,烟叶中吲唑磺菌胺残留量为<LOQ^5.95 mg/kg。

To study the residue and dissipation of amisulbrom in tobacco of crop field trials, a QuEChERS method combined with LC-MS/MS was developed. Samples were extracted with acetonitrile, cleaned up by primary secondary amine, and detected by LC-MS/MS with quantification by external standard method. It was showed that the average recoveries of amisulbrom were 88% - 93% and 93% - 107% with relative standard deviations of 2.5% - 13.9% and 6.7% -7.4% in fresh and cured tobacco leaves, respectively. The limits of quantification were 0.01 mg/kg and 0.02 mg/kg for fresh and cured tobacco leaves, respectively. The dissipation and final residues of amisulbrom in tobacco were determined in Shandong and Sichuan, China during 2013 to 2014. The dissipation results showed the half-lives of amisulbrom in fresh tobacco leaves were 5.1 - 9.8 days. The final residues of amisulbrom in cured tobacco leaves were determined after three or four applications at 105 g a. i./hm2 and 157.5 g a. i./hm2. The final residues of amisulbrom were all in the range of below LOQ to 5.95 mg/kg 14 days after the last application in cured tobacco leaves.