质谱参数改变对化合物负离子化学电离质谱行为的影响  

Effects of Variation in Mass Spectrometric Parameters upon Behaviour of Anion Chemical Ionization Mass Spectrometry of Compounds

作　　者：姚钟平[1] 胡耀铭[1] 陈培青 林子森 

机构地区：[1]复旦大学分析测试中心,中山大学测试中心200433

出　　处：《分析测试学报》1993年第3期27-31,共5页Journal of Instrumental Analysis

摘　　要：负离子化学电离质谱中负离子的相对丰度随着离子源压力、电子能量和离子源温度等质谱参数的改变发生了明显的变化。负离子形成过程中共振电子俘获和裂解电子俘获之间的竞争与质谱参数有关,其中以离子源温度的影响最为显著。热电子的比例随着离子源压力增大而减小,随着电子能量增大而增大。低离子源温度有利于共振俘获形成分子负离子,而高离子源温度则有利于裂解电子俘获形成碎片负离子,特别是热力学稳定的负离子。Relative abundances of anions in negative ion chemical ionization mass spectrometry varywith variation in mass spectrometric parameters e. g. ion source pressure, electron energy and ionsource temperature. In the mechanism of anion formation, the competition between resonanceelectron capture and dissociative electron capture is also associated with these parameters, andmore stongly associated with ion source temperature. The thermal electornic ratio decreases withincreasing ion source pressure and conversely increases with increasing electron energy. Low ionsource temperature favors resonance electron capture to form molecular anions, while high ion sourcetemperature favors dissociative electron capture to give rise to fragment anions, especially ther-modynamically stable anions.

关 键 词：负离子 化学电离质谱 离子源压力 

分 类 号：O657.6[理学—分析化学]