Formation of oligomeric alkenylperoxides during the oxidation of unsaturated fatty acids: an electrospray ionization tandem mass spectrometry study

✍ Scribed by Juan José Villaverde; Sónia A. O. Santos; Elisabete Maciel; Mário M. Q. Simões; Carlos Pascoal Neto; M. Rosário M. Domingues; Armando J. D. Silvestre

• Publisher: John Wiley and Sons
• Year: 2012
• Tongue: English
• Weight: 451 KB
• Volume: 47
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.2047

✦ Synopsis

This study reports the identification of oligomeric alkenylperoxides by electrospray ionization mass spectrometry (ESI‐MS) and tandem mass spectrometry (ESI‐MS^2^), during the oxidation of oleic, linoleic and linolenic acids with Fenton's (Fe^2+^/H~2~O~2~) and Fe^2+^/O~2~ systems. The reactions were followed by ferrous oxidation‐xylenol orange method together with GC‐MS and GC‐FID, allowing to observe that both oxidation systems are different in terms of hydroperoxide evolution, probably due to the presence of different intermediate reactive species: perferryl ion and OH^·^ radical responsible for the decomposition of lipid hydroperoxides and formation of new compounds.

The analysis of ESI‐MS in the negative mode, obtained after oxidation of each fatty acid, confirmed the presence of the monomeric oxidation products together with other compounds at high mass region above m/z 550. These new ions were attributed to oligomeric structures, identified by the fragmentation pathways observed in the tandem mass spectra. Copyright © 2012 John Wiley & Sons, Ltd.