前言：

We tested the performance of a novel mass spectrometer, he LTQ Orbitrap, in a multitude of different applications n the field of lipidomics. The experiments presented here ake advantage of the LTQ Orbitrap capabilities of multiple tage fragmentation, high resolution and mass accuracy to olve challenges of quantitating isomeric glycerophospholipids, esolving isobaric species, and elucidating ragmentation pathways and compositional assignment f various lipid species.

仪器：

LTQ Orbitrap hybrid mass spectrometer

结论：

The LTQ Orbitrap is a novel mass spectrometer capable of delivering high resolution and high mass accuracy.

• The MSn capability proved essential for identifying positional isomers of PCs in mixtures.

• It also allowed for the relative quantitation of isomeric PCs in a mixture without internal standards.

• Resolving power of at least 30,000 is needed in the full scan mode to resolve isobaric species of glycerophospholipids.

• The presence of isobaric species was also confirmed in MS/MS fragmentation spectrum acquired at high resolution.

• The mass accuracy of the measurement in MS and MSn mode was always better than 3.5 ppm for either parent or fragment ions applying external calibration.

• The time scale for acquiring such high quality data is compatible with on-line chromatographic separation.