Boreham D R, Ford G C, Haskins N J, Vose C W, Palmer R F
Biomed Mass Spectrom. 1978 Sep;5(9):524-30. doi: 10.1002/bms.1200050904.
Electron impact and chemical ionization mass spectra are reported for several steroidal spirolactones and their TMS ethers. The electron impact spectra were characterized generally by low abundance molecular ions and large numbers of fragment ions. Methane chemical ionization spectra exhibited high intensity [M+H]+ and/or [M+H-H2O]+ or [M+H-TMSOH]+ ions with few other fragment ions. Ammonia chemical ionization spectra had intense [M+H]+ and/or [M+NH4]+ ions with a few fragment ions generally formed by loss of H2O or TMSOH from these parent ions. Ammonia chemical ionization gave intense parent ions even for polyhydroxy compounds and their TMS ethers in contrast to methane chemical ionization. The results of this study suggest that a combination of electron impact with ammonia chemical ionization mass spectrometry would offer the best techniques for detection and identification of these compounds in biological fluids.
报道了几种甾体螺内酯及其TMS醚的电子轰击质谱和化学电离质谱。电子轰击质谱的一般特征是分子离子丰度低且碎片离子数量多。甲烷化学电离质谱显示出高强度的[M + H]+和/或[M + H - H2O]+或[M + H - TMSOH]+离子，其他碎片离子很少。氨化学电离质谱具有强烈的[M + H]+和/或[M + NH4]+离子，通常由这些母离子失去H2O或TMSOH形成少量碎片离子。与甲烷化学电离相比，即使对于多羟基化合物及其TMS醚，氨化学电离也能产生强烈的母离子。本研究结果表明，电子轰击与氨化学电离质谱联用将为生物体液中这些化合物的检测和鉴定提供最佳技术。
