5种吡咯烷酮衍生物的电喷雾离子阱质谱分析初探

Preliminary study on electrospray ion trap mass spectrometry analysis of five pyrrolidone derivatives

目的探讨5种结构相似的吡咯烷酮衍生物的质谱裂解规律。方法在正离子检测方式下,用电喷雾离子阱质谱法对吡拉西坦、奥拉西坦、茴拉西坦、奈非西坦和左乙拉西坦进行多级质谱分析。结果各化合物在二级质谱分析时,均可发生酰胺键断裂,生成脱去含氮基团的碎片离子m/z126(吡拉西坦和奈非西坦)、m/z142(奥拉西坦)、m/z135(茴拉西坦)、m/z154(左乙拉西坦);在三级质谱分析时,除茴拉西坦外,则进一步发生脱去羰基的反应,生成稳定的碎片离子m/z98、m/z114和m/z126。结论通过多级质谱分析可获得吡咯烷酮衍生物分子丰富的结构信息,并可用于该类化合物的快速结构解析和定量分析。

Aim To study the dissociation pathways of five 2-pyrrolidone derivatives. Methods In positive mode,five 2-pyrrolidone derivatives were elucidated by use of eleetrospray ion trap mass spectrometry in the multi-stage MS full scan mode. Results It was demonstrated that the five 2-pyrrolidone derivatives gave abundant product ions at m/z126 （piracetam and nefiracetam）, rn/z142 （oxiracetam） ,m/z135 （aniraeetam） ,m/z154 （levetiraeetam） by loss of the N-group （ NH3 or its derivatives） in MS2 full scan mode. In MS3 full scan mode,except aniraeetam,the prominent fragmentation ions at m/z98 ,m/z114 and m/z126 were formed from the fragmentation ions at m/z126,m/z142 and m/z154 by loss of the carbonyl,separately. Conclusion The structural information was obtained via collisionactivated dissociation and these characteristics are applicable to the structural elucidation and quantitative analysis of 2-pyrrolidone derivatlves.