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Electron ionization mass spectral fragmentation of C 19 isoprenoid aldehydes and carboxylic acid methyl and trimethylsilyl esters
Author(s) -
Rontani J.F.,
Aubert C.
Publication year - 2003
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1004
Subject(s) - chemistry , trimethylsilyl , fragmentation (computing) , electron ionization , mass spectrum , carboxylic acid , conjugated system , chemical ionization , double bond , ion , medicinal chemistry , mass spectrometry , aldehyde , hydrogen , ionization , photochemistry , stereochemistry , organic chemistry , catalysis , chromatography , polymer , computer science , operating system
The electron ionization (EI) mass spectra of saturated and α , β ‐unsaturated C 19 isoprenoid aldehydes and carboxylic acid methyl and trimethylsilyl esters are reported. Different pathways are proposed in order to explain the main fragmentations observed. The conjugated double bond migrates more or less readily before γ ‐hydrogen rearrangement according to the structure of the considered compound. Configurations of the double bond of α , β ‐unsaturated C 19 isoprenoid aldehydes and fatty acid methyl and trimethylsilyl esters can be easily determined thanks to the peaks at m/z 97, 127 and 185, respectively, which are much more abundant in the mass spectra of the Z isomers owing to the formation of a cyclic ion. In the case of trimethylsilyl esters, subsequent fragmentation of the cyclic ion at m/z 185 affords two other diagnostic ions at m/z 95 and 169. Copyright © 2003 John Wiley & Sons, Ltd.