Nano-LC/NSI MS Refines Lipidomics by Enhancing Lipid Coverage, Measurement Sensitivity, and Linear Dynamic Range

Nano-liquid chromatography (nLC)-nanoelectrospray (NSI) is one of the cornerstones of mass-spectrometry-based bioanalytics. Nevertheless, the application of nLC is not yet prevalent in lipid analyses. In this study, we established a reproducible nLC separation for global lipidomics and describe the merits of using such a miniaturized system for lipid analyses. In order to enable comprehensive lipid analyses that is not restricted to specific lipid classes, we particularly optimized sample preparation conditions and reversed-phase separation parameters. We further benchmarked the developed nLC system to a commonly used high flow HPLC/ESI MS system in terms of lipidome coverage and sensitivity. The comparison revealed an intensity gain between 2 and 3 orders of magnitude for individual lipid classes and an increase in the linear dynamic range of up to 2 orders of magnitude. Furthermore, the analysis of the yeast lipidome using nLC/NSI resulted in more than a 3-fold gain in lipid identifications. All in all, we identified 447 lipids from the core phospholipid lipid classes (PA, PE, PC, PS, PG, and PI) in Saccharomyces cerevisiae.