Structural identification of human blood phospholipids using liquid chromatography/quadrupole-linear ion trap mass spectrometry

A normal-phase liquid chromatography/quadrupole-linear ion trap mass spectrometry method was developed for the separation and mass spectral characterization of the main phospholipid species in human blood. The instrument combines the capabilities of a triple quadrupole mass spectrometer and ion trap technology on a single platform. The optimal separation was achieved by using hexane/1-propanol as mobile phase and 0.6% formic acid, 0.06% ammonia as modifiers. The HPLC/MS technique was able to provide information about the molecular mass of individual homologues by positive and negative turbo ionspray. More complete characterization of fatty acid chains and of the polar head group was obtained by using a quadrupole collisionally activated dissociation (CAD) spectrum with ion trap sensitivity. The mass spectra and molecular species of phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine (PC), lysophosphatidylcholine (lysoPC) and sphingomyelin (SM) are presented. (C) 2004 Elsevier B.V. All rights reserved.