生物检材中甲基异柳磷的LC-MS和GC-MS检验

Determination of Isofenphos Methyl by LC-MS and GC-MS in Biological Materials

[目的]基于精确质量数的线性离子阱静电场轨道阱组合式高分辨质谱(LTQ-Orbitrap),结合气相色谱二维线性离子阱质谱方法,分析生物检材中的有机磷农药甲基异柳磷。[方法]生物检材采用二氯甲烷-三氯甲烷(体积比为1∶1)提取,LC-MS和GC-MS检测。[结果]通过LTQ-Orbitrap的一级全扫描模式,以精确质量数确定血、胃组织和肝脏中甲基异柳磷的准分子离子峰为m/z 332.10[M+H]+,结合特征离子碎片的精确质量数,探讨了甲基异柳磷在ESI-MS正离子扫描下可能的质谱裂解规律,通过与EI-MS谱图的比对,分析了其在2种电离条件下裂解途径的相同点,对于甲基异柳磷结构的确认得以相互印证。[结论]该方法可以用于实际案例中有机磷农药甲基异柳磷的检验分析。

Base on linear electrostatic ion hybrid high resolution mass（LTQ-Orbitrap） and gas chromatographic hyphenated planar-linear ion trap,the method,was developed for the analysis and identification of organic phosphate pesticide-isofenphos methyl in biological samples.[Methods] Samples were extracted by dichloromethane： chloroform（1∶1,by vol）,and detected by LC-MS and GC-MS.[Results] In this paper,m/z 332.10 ＋ was considered as the quasimolecular ion of isofenphos methyl in the blood,stomach tissue and liver by the first full scan mode of LTQ-Orbital.Base on quasimolecular ion and its characteristic fragment ion,the split mode of isofenphos methyl in the positive ESI-MS was discussed.By the comparison with the EI-MS spectrogram,the similarity of split pathway under the two different ionization conditions was analyzed and it would contribute to the identification of isofenphos methyl.[Conclusions] This method could be used for the analysis and identification of the organic phosphate-isofenphos methyl in the actual case.