Premium
Effect of structure on the electron‐capture negative ionization mass spectrometric response of steroids
Author(s) -
Mayer Helen K.,
Reusch William,
Watson J. Throck
Publication year - 1992
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210270504
Subject(s) - chemistry , degree of unsaturation , conjugated system , fragmentation (computing) , double bond , halogen , substituent , ketone , electron ionization , steroid , medicinal chemistry , photochemistry , stereochemistry , ionization , organic chemistry , alkyl , ion , biochemistry , polymer , computer science , hormone , operating system
The key to enhanced electron‐capture negative ion mass spectrometry (ECNI‐MS) response of ketosteroids is extensive α,β‐unsaturation. Combinations of double bonds, carbonyl groups, epoxides and halogens within a steroid nucleus were correlated with their ECNI responses. The greatest ECNI responses result from extensive conjugation, such as the linearly conjugated 4‐ene‐3,6‐dione system and the cross‐conjugated 1,4‐diene‐3,11‐dione system. In general, an epoxy ketosteroid has a relative response 40 times greater than that of its corresponding enone. In an α‐halo ketone, an axial halogen substitution will increase the relative response by an order of magnitude, but an equatorial halogen substituent will not affect the response. The fragmentation of ketosteroids as related to ECNI response is discussed.