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Updated: Jul 17, 2026

Identification of Fatty Acids in Bacillus cereus
Published on: December 5, 2016
Distinguishing between cis/trans isomers of monounsaturated fatty acids by FAB MS
Hong Ji1, Valery G Voinov, Max L Deinzer
1Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.
Abstract:
Fast-atom bombardment (FAB) mass spectrometry in the negative ion mode can be used to unambiguously distinguish between cis and trans isomers of monounsaturated fatty acids by the relative signal strengths of an intense pair of ion signals. Under normal FAB ionization/desorption conditions, the deprotonated molecules (i.e., [M - H]-) of six fatty acids underwent charge remote fragmentation. A characteristic fragmentation pattern of two intense peak clusters of peaks with three weak intervening clusters of peaks are used in each case to identify the position of the double bond. The possibility of resonance electron capture occurring during the FAB process is discussed.
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