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Examining the collision‐induced decomposition spectra of ammoniated triglycerides. III. The linoleate and arachidonate series
Author(s) -
Gakwaya Robert,
Li Xingwen,
Wong Yin Ling,
Chivukula Swathilekha,
Collins Elizabeth J.,
Evans Jason J.
Publication year - 2007
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.3208
Subject(s) - chemistry , degree of unsaturation , ion , double bond , fatty acid , decomposition , mass spectrometry , mass spectrum , analytical chemistry (journal) , organic chemistry , chromatography
A series of positionally pure triglycerides (TAGs) of the form LXL, YLY, AXA, and YAY was synthesized and analyzed by reversed‐phase high‐performance liquid chromatography/tandem mass spectrometry. L and A represent the linoleate and arachidate moieties, respectively, and X and Y represent large arrays of fatty acid moieties of various chain lengths, degree of unsaturations, double‐bond positions, and cis/trans configurations. The abundances of the collision‐induced decomposition (CID) products of ammoniated TAGs were examined as a function of these parameters. The major CID products, the diglyceride (DAG) product ions and the MH + ions, are plotted as functions of chain length for the saturated and monounsaturated series of X and Y. The following trends are observed in the data. TAGs with higher degrees of unsaturation tend to show greater relative abundances of MH + in the CID spectra of their ammoniated precursor ions. The position of the fatty acid constituents along the glycerol backbone also seems to influence the abundances of the MH + ion in the CID spectra of the ammoniated precursor ions. A fatty acid constituent with double bonds along the fatty acid chain positioned close to the carbonyl promotes the formation of the DAG product ion that corresponds to its loss upon CID of the ammoniated precursor ion. Linoleic acid substituents also seem to promote the formation of DAG product ions, but to a lesser extent. Data for the YAY TAGs are used to predict the abundances of the product ions in the CID spectra of ammoniated YAX TAGs. These data are discussed in context of a broader project to develop and validate software algorithims to support a platform for comprehensive analysis of complex mixtures of TAGs. Copyright © 2007 John Wiley & Sons, Ltd.