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Regioisomer characterization of triacylglycerols by non‐aqueous reversed‐phase liquid chromatography/electrospray ionization mass spectrometry using silver nitrate as a postcolumn reagent
Author(s) -
Lévêque Nathalie L.,
Héron Sylvie,
Tchapla Alain
Publication year - 2010
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1713
Subject(s) - chemistry , reagent , chromatography , electrospray ionization , mass spectrometry , extractive electrospray ionization , aqueous solution , electrospray , silver nitrate , sample preparation in mass spectrometry , direct electron ionization liquid chromatography–mass spectrometry interface , hydrophilic interaction chromatography , liquid chromatography–mass spectrometry , chemical ionization , high performance liquid chromatography , ionization , ion , organic chemistry
Triacylglycerols (TAGs) provide a challenge for mass spectrometry (MS) analysis because of their complexity. In particular, for dietary, nutritional and metabolic purposes, the positional placement of fatty acids on the glycerol backbone of TAGs is a crucial aspect. To solve this problem, we have investigated the TAGs' fragmentation patterns using an ion trap mass spectrometer. A series of pure regioisomeric pairs of TAGs (POP/PPO, POO/OPO and OSO/SOO) were cationized by Ag + after their separation by non‐aqueous reversed‐phase liquid chromatography (NARP‐LC) before MS to improve MS sensitivity. Electrospray ionization–MS (ESI‐MS) conditions were optimized in order to produce characteristic [M + Ag + AgNO 3 ] + ions from each TAG, which were then fragmented to produce MS/MS spectra and then fragmented further to produce up to MS 5 spectra. The observation of ions produced by LC‐MS 5 of on‐line Ag + ‐cationized TAG provided unambiguous information on the fatty acid distribution on the glycerol backbone. These strategies of MS to MS 5 experiments were applied to identify components and to determine the regiospecificity of TAG within a complex mixture of lipids in natural oils. Copyright © 2010 John Wiley & Sons, Ltd.