| Quantitative analysis of positional isomers of triacylglycerols via electrospray ionization tandem mass spectrometry of sodiated adducts. | |
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MedLine Citation:
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PMID: 20814981 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Herein we report a reversed-phase high-performance liquid chromatography tandem mass spectrometry (RP-HPLC/MS/MS) method for the analysis of positional isomers of triacylglycerols (TAGs) in vegetable oils. The fragmentation behavior of [M + X](+) ions (X = NH(4), Li, Na or Ag) was studied on a quadrupole-time-of-flight (Q-TOF) mass spectrometer under low-energy collision-induced dissociation (CID) conditions. Mass spectra that were dependent on the X(+) ion and the nature and position of the acyl substituents were observed for four pairs of 'AAB/ABA'-type TAGs, namely PPO/POP, OOP/OPO, LLO/LOL and OOL/OLO (where P is 16:0, palmitic acid; O is 18:1, oleic acid; and L is 18:2, linoleic acid). For the majority of [M + X](+) adducts, the loss of the fatty acid in the outer positions (sn-1 or sn-3) was favored over the loss in the central position (sn-2), which enabled the determination of the fractional abundance of the isomers. Ratios of the intensity of fragment ions at various AAB/ABA compositions produced linear calibration curves with positive slopes, comparable to those obtained traditionally by ESI-MS/MS of [M + NH(4)](+) adducts. The only exceptions were the [M + Ag](+) adducts of the PPO/POP system, which produced calibration curves with negative slopes. Sodium adducts provided the most consistent level of isomeric discrimination for the TAGs studied and also offered the most convenience in that they required no additive to the mobile phase. Therefore, calibration curve data derived from [M + Na](+) adducts were applied to the quantification of TAG regioisomers in sunflower and olive oils. The regiospecific analysis showed that palmitic acid was typically located at positions sn-1 or sn-3, whereas unsaturated fatty acids, oleic and linoleic acids were mostly found at the sn-2 position. |
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Authors:
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Lisandra Cubero Herrera; Michael A Potvin; Jeremy E Melanson |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Rapid communications in mass spectrometry : RCM Volume: 24 ISSN: 1097-0231 ISO Abbreviation: Rapid Commun. Mass Spectrom. Publication Date: 2010 Sep |
Date Detail:
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Created Date: 2010-09-03 Completed Date: 2011-01-04 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8802365 Medline TA: Rapid Commun Mass Spectrom Country: England |
Other Details:
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Languages: eng Pagination: 2745-52 Citation Subset: IM |
Copyright Information:
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2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. |
Affiliation:
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National Research Council of Canada, Institute for Marine Biosciences, Halifax, Nova Scotia, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Chromatography, High Pressure Liquid Linear Models Methanol / chemistry Palmitic Acid / chemistry Plant Oils / chemistry Sodium / chemistry Spectrometry, Mass, Electrospray Ionization / methods* Stereoisomerism Tandem Mass Spectrometry / methods* Triglycerides / chemistry* |
| Chemical | |
Reg. No./Substance:
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0/Plant Oils; 0/Triglycerides; 57-10-3/Palmitic Acid; 67-56-1/Methanol; 7440-23-5/Sodium; 8001-21-6/sunflower seed oil; 8001-25-0/olive oil |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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