Desorption/ionization efficiencies of triacylglycerols and phospholipids via EASI-MS

• Published in: Journal of mass spectrometry. Vol. 49; no. 5; pp. 335 - 341
• Main Authors: Fernandes, Anna Maria A. P., Fernandes, Gabriel D., Barrera-Arellano, Daniel, de Sá, Gilberto F., Lins, Roberto D., Eberlin, Marcos N., Alberici, Rosana M.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-05-2014; Wiley Subscription Services, Inc
• Subjects: Carbon; Chains; Computational efficiency; Computing time; Desorption; desorption/ionization efficiency; easy ambient sonic-spray ionization; Ionization; lipids; Mass spectrometry; Molecular Dynamics Simulation; Phospholipids; Phospholipids - analysis; Phospholipids - chemistry; Spectrometry, Mass, Electrospray Ionization - methods; triacylglycerols; Triglycerides - analysis; Triglycerides - chemistry; desorption/ionization efficiency; lipids; triacylglycerols; easy ambient sonic-spray ionization; phospholipids; molecular dynamics simulation
• ISSN: 1076-5174; 1096-9888
• DOI: 10.1002/jms.3366

Knowledge of the major effects governing desorption/ionization efficiency is required for the development and application of ambient mass spectrometry. Although all triacylglycerols (TAG) have the same favorable protonation and cationization sites, their desorption/ionization efficiencies can vary dramatically during easy ambient sonic‐spray ionization because of structural differences in the carbon chain. To quantify this somewhat surprising and drastic effect, we have performed a systematic investigation of desorption/ionization efficiencies as a function of unsaturation and length for TAG as well as for diacylglycerols, monoacylglycerols and several phospholipids (PL). Affinities for Na+ as a function of unsaturation level have also been assayed via comprehensive metadynamics calculations to understand the influence of this phenomenon on the ionization efficiency. The results suggest that dipole–dipole interactions within a carbon chain tuned by unsaturation sites govern ionization efficiency of TAG and PL. Copyright © 2014 John Wiley & Sons, Ltd.