ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The nature and location of a variety of modifications of fatty acids are determined by collisional activation (CA) of [M + 2Li - H]+ ions. The sample molecules are cationized in situ on the probe tip, desorbed by fast atom bombardment and, upon CA, undergo charge-remote decompositions. This approach is a direct, totally instrumental method for structure elucidation. Advantages of CA of [M + 2Li - H]+ ions are that fatty acids with substituents in close proximity to the carboxylate terminus and modified short-chain acids are readily determined: decompositions of carboxylate anions of these fatty acids result in collision-activated dissociation (CAD) spectra that give incomplete structural information. However, the CAD spectra of some [M - H]- ions, such as those from epoxy acids, are simpler to interpret than those of the [M + 2Li - H]+ ions. Thus, CA of fatty acid [M + 2Li - H]+ ions is a complementary approach to CA of [M - H]- ions for determining the fatty acid structures investigated here. The use of this approach for analyzing complex mixtures of modified fatty acids is also evaluated.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210230505
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