RESUMO
Collision-induced fragmentation of the [M + Na]+ and [M + H]+ ions generated from 3-[4-bis-N,N-(2-chloroethyl)aminophenyl]acetates in the estrane series under electrospray/ionization was studied. Some regularities in fragmentation pathways depending on the nature of functional groups were established. Formation of the [(M + Na) NaCl]+ ions along with [(M + Na) HCl]+ ions from the [M + Na]+ ions was explained using quantum chemical calculations for some simplified models.
Assuntos
Acetatos/química , Modelos Químicos , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Simulação por Computador , Teoria QuânticaRESUMO
The fragmentation of [M+Na](+) ions produced from steroid 11beta-nitrates during electrospray/ionization (ESI) was studied by using ion trap MS/MS technique. The [M+Na](+) ions eliminate NO(2) and HNO(3) for epimers bearing 9beta and 9alpha substituents, respectively. As the main fragmentation pathways are determined mainly by the configuration at C-9 and alternative fragmentation does not practically occur, this offers the possibility for the determination of the configuration at chiral C-9 centre in the estrane 11beta-nitrate series by ESI mass spectrometry.