A Comprehensive Method for Lipid Profiling by Liquid Chromatography-Ion Cyclotron Resonance Mass Spectrometry

Abstract
The instrumental setup elaborated comprises reversed-phase HPLC coupled to a Fourier transform ion cyclotron resonance mass spectrometer (LTQ-FT), and Lipid Data Analyzer (LDA) software. Data analysis for lipid species profiling in this platform is based on retention time, mass resolution of 200,000, and mass accuracy below 2 ppm. In addition, automatically generated MS/MS spectra provide structural information at molecular level. This LC/MS technology allows analyzing complex biological samples in a quantitative manner as shown here paradigmatically for murine lipid droplets having a huge surplus of triacylglycerol species. Chromatographic pre-separation of the bulk lipid class alleviates the problem of ion suppression of lipid species from other classes. Extension of 1D to 2D chromatography is possible, yet time consuming. The dynamic range of the platform enables unambiguous determination of lipid species in major lipid classes as low as 0.01%. Taken together, a novel lipidomic LC/MS platform based on chromatographic retention, high mass resolution and accuracy, MS/MS analysis and quantitation software enables analysis of complex samples as demonstrated for lipid droplets.

The article is published online in the Journal of Lipid Research and is free to access.