【摘要】 采用电喷雾多级串联质谱技术,对头孢呋辛、头孢噻吩钠、头孢硫脒、头孢噻利、头孢西丁钠五种头孢菌素类抗生素进行了系统研究,总结了该类化合物的电喷雾质谱特征断裂机理。该类化合物在电喷雾正离子或负离子模式下,均发生C-3位侧链C-X(X=O、N、S)键的特征断裂,为头孢菌素类抗生素化合物结构鉴定提供了新方法。在负离子模式下,头孢呋辛二级质谱中β-内酰胺环发生开环断裂,与文献结果一致;在电喷雾正离子模式下,头孢噻吩钠、头孢噻利、头孢西丁钠多级串联质谱中均失去C-7位侧链上一分子CO。更多还原

【Abstract】 Electrospray ionization multi-stage tandem mass spectrometry(ESI-MS~n) is applied to analysis of five cephalosporins,including cefuroxime,cefalotin sodium,cefathiamidine,cefoselis and cefoxitin sodium,which are one classes of antibiotics widely used in the prevention and treatment of infectious diseases in the recent years.And their fragmentation pathways are described.The cleavage of C-X(X=O,N and S) in the site of C-3 is the characteristic fragmentation pathway of cephalosporins,both in the negative and positive ion mode.Additionally,in the MS~2 spectra of negative ion mode of cefuroxime,β-lactam cleaves between C6-7 and C8-N1 which is the same as reference papers described.In the MS~n spectra of positive ion mode of cefuroxime,cefalotin sodium,cefoselis and cefoxitin sodium,a neutral loss of CO happens at the side chain of C-7.更多还原