Fast liquid chromatography–quadrupole linear ion trap-mass spectrometry analysis of polyunsaturated fatty acids and eicosanoids in human plasma

Profiling of polyunsaturated fatty acids (PUFAs) and their oxidized metabolites, mainly eicosanoids, in human plasma by fast liquid chromatography–mass spectrometry is described. Sample preparation involved protein precipitation of 200 μL plasma followed by on-line solid-phase extraction. 7 PUFAs and 94 oxidized metabolites were separated utilizing a C-18 column packed with 2.6 μm core–shell particles in 7 min. The analytes and deuterium-labeled standards were detected via scheduled multiple reaction monitoring transitions (123 sMRM). Simultaneously, linear ion trap fragment spectra were acquired for confirmation, if necessary. The lower limit of quantitation ranged between 200 and 1000 ng/mL for the PUFAs and 10–1000 pg/mL for the metabolites. The method was applied to a study on plasma samples from 50 healthy subjects.