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.