Structural identification of triacylglycerol isomers using electron impact excitation of ions from organics (EIEIO)

Takashi Baba,J Larry Campbell,J C Yves Le Blanc,Paul R.S Baker

doi:10.1194/jlr.m070177

Takashi Baba, J Larry Campbell + Show 2 more

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https://doi.org/10.1194/jlr.m070177

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Abstract

Electron-induced dissociation or electron impact excitation of ions from organics (EIEIO) was applied to triacylglycerols (TAGs) for in-depth molecular structure analysis using MS. In EIEIO, energetic electrons (∼10 eV) fragmented TAG ions to allow for regioisomeric assignment of identified acyl groups at the sn-2 or sn-1/3 positions of the glycerol backbone. In addition, carbon-carbon double bond locations within the acyl chains could also be assigned by EIEIO. Beyond the analysis of lipid standards, this technique was applied to edible oils and natural lipid extracts to demonstrate the power of this method to provide in-depth structural elucidation of TAG molecular species.

Highlights

Electron-induced dissociation or electron impact excitation of ions from organics (EIEIO) was applied to triacylglycerols (TAGs) for in-depth molecular structure analysis using MS
EIEIO provides characteristic fragments for TAGs In previous studies [18, 19], we have demonstrated the utility of EIEIO for providing detailed structural information for different types of polar lipids
We have demonstrated the utility of combining differential mobility spectrometry (DMS) and EIEIO to provide in-depth characterization of TAGs

Summary

Introduction

Electron-induced dissociation or electron impact excitation of ions from organics (EIEIO) was applied to triacylglycerols (TAGs) for in-depth molecular structure analysis using MS. A common method of TAG analysis is the chromatographic detection of FFAs or their derived methyl or ethyl esters, which are obtained by hydrolysis from TAGs [4] Convenient, this method does not allow for consideration of the structural aspects of the intact TAG molecular species (i.e., regioisomeric structural information). A conventional TAG characterization method in MS is based on low-energy [5, 6] or high-energy collision-induced dissociation (CID) [7, 8] These methods provide TAG structural information, including acyl chain lengths and double bond number; the double bond positions and the acyl chain regioisomeric arrangement are not defined due to the limited information derived from the resultant fragments.

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