硅烷化法在卤代物质谱分析中的新应用

Application of Silylation in Mass Spectrometry Analysis of Organic Halides

利用气相色谱-质谱法对一系列脂肪卤化物及芳香卤化物的三甲基硅烷基(TMS)衍生物在电子轰击离子源(EI)下的裂解行为进行了研究。质谱分析结果表明:有机卤化物的TMS衍生物在发生碎裂反应的过程中均生成元素组成符合[(CH_3)_2XSi]^+(X=F、Cl、Br、I)的特征骨架重排产物离子,即m/z 77、m/z 93、m/z 137、m/z 185。此外,卤素原子取代位置的改变对重排产物离子峰的强度、类型也产生了显著影响。通过对这一类重排产物离子的研究,可快速、有效的鉴别卤代物的位置异构体,以及逆向分析有机分子的元素组成。此硅烷化的分析手段不仅可为有机卤代化合物结构的解析提供新的思路,同时也可拓展硅烷类衍生化试剂在有机质谱分析领域中的应用。

A gas chromatography-mass spectrometry(GC-MS)method was used for investigation of the fragmentation behavior of a series of trimethylsilyl(TMS)derivatives of aliphatic halides and aromatic halides under the environment of electron impact ion source(EI)in order to acquire it’s fragmentation regularity,which,in return,provided guidance for the structure of organic halogenated compounds.The results of mass spectral indicated that the TMS derivatives of organic halides produced characteristic skeleton rearrangement product ions with elemental composition conforming to[(CH3)2XSi]^+(X=F,Cl,Br,I)during the fragmentation reaction,namely m/z 77,m/z 93,m/z 137 and m/z 185.In addition,the change in the position of the halogen atom substitution also had significant effect on the intensity and type of the rearranged product ion peak.Through the study of this type of rearranged product ions,the positional isomers of the halogenated compounds could be identified quickly and efficiently,and the elemental composition of the organic molecules could be reversely analyzed.This analysis method not only provided a new idea for the analysis of the structure of organic halogenated compounds,but also expanded the application of silane derivatization reagents in the field of organic mass spectrometry.