U.S. Department of Energy

Pacific Northwest National Laboratory

Separation and classification of lipids using differential ion mobility spectrometry.

TitleSeparation and classification of lipids using differential ion mobility spectrometry.
Publication TypeJournal Article
Year of Publication2011
AuthorsShvartsburg AA, Isaac G, Leveque N, Smith RD, Metz TO
JournalJ Am Soc Mass Spectrom
KeywordsGlycerides, Glycerophospholipids, Glycolipids, Helium, Ions, Isomerism, Linear Models, Mass Spectrometry

Correlations between the dimensions of a 2-D separation create trend lines that depend on structural or chemical characteristics of the compound class and thus facilitate classification of unknowns. This broadly applies to conventional ion mobility spectrometry (IMS)/mass spectrometry (MS), where the major biomolecular classes (e.g., lipids, peptides, nucleotides) occupy different trend line domains. However, strong correlation between the IMS and MS separations for ions of same charge has impeded finer distinctions. Differential IMS (or FAIMS) is generally less correlated to MS and thus could separate those domains better. We report the first observation of chemical class separation by trend lines using FAIMS, here for lipids. For lipids, FAIMS is indeed more independent of MS than conventional IMS, and subclasses (such as phospho-, glycero-, or sphingolipids) form distinct, often non-overlapping domains. Even finer categories with different functional groups or degrees of unsaturation are often separated. As expected, resolution improves in He-rich gases: at 70% He, glycerolipid isomers with different fatty acid positions can be resolved. These results open the door for application of FAIMS to lipids, particularly in shotgun lipidomics and targeted analyses of bioactive lipids.

Alternate JournalJ. Am. Soc. Mass Spectrom.
PubMed ID21953096
PubMed Central IDPMC3187568
Grant ListDK071283 / DK / NIDDK NIH HHS / United States
P41 RR018522-08 / RR / NCRR NIH HHS / United States
R33 DK071283-05 / DK / NIDDK NIH HHS / United States
RR 18522 / RR / NCRR NIH HHS / United States
U54AI081680 / AI / NIAID NIH HHS / United States
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