Mass spectrometric analysis of platelet-activating factor after isolation by solid-phase extraction and direct derivatization with pentafluorobenzoicanhydride

Platelet-activating factor is the term used to denote a class of extremely patent lipid mediators that consist predominantly of 1-O-alkyl- and 1-O-acy l-2-acetyl-sn-glycero-3-phosphocholines. A method has been devised for rapi d isolation of these acetylated phospholipids by solid-phase extraction pri or to direct derivatization with pentafluorobenzoic anhydride and analysis by gas chromatography (GC)/electron-capture mass spectrometry. Recovery thr ough the entire method (lipid isolation, derivatization, and purification) typically ranged from 70% to 85%. Using the direct derivatization procedure described here, the practical limit of detection for each of the standard alkyl- and acyl-platelet-activating factor homologs was 1 fmol injected int o the GC. Results from the application of the method to the analysis of alk yl and acyl homologs of platelet-activating factor isolated from stimulated human umbilical vein endothelial cells are presented, exhibiting excellent accuracy and precision for a wide range of tissue levels of this class of potent autacoids. (C) 2000 American Society for Mass Spectrometry.