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Effect of structure on the electron-capture negative ionization mass spectrometric response of steroids

✍ Scribed by Helen K. Mayer; William Reusch; J. Throck Watson

Publisher
John Wiley and Sons
Year
1992
Tongue
English
Weight
676 KB
Volume
27
Category
Article
ISSN
1076-5174

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✦ Synopsis

Abstract

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.

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