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Molecular species of sphingomyelin: determination by high‐performance liquid chromatography/mass spectrometry with electrospray and high‐performance liquid chromatography/tandem mass spectrometry with atmospheric pressure chemical ionization
Author(s) -
Karlsson Anders Å.,
Michélsen Peter,
Odham Göran
Publication year - 1998
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/(sici)1096-9888(199812)33:12<1192::aid-jms735>3.0.co;2-j
Subject(s) - chemistry , chromatography , mass spectrometry , direct electron ionization liquid chromatography–mass spectrometry interface , tandem mass spectrometry , electrospray , atmospheric pressure chemical ionization , extractive electrospray ionization , electrospray ionization , liquid chromatography–mass spectrometry , high performance liquid chromatography , sample preparation in mass spectrometry , chemical ionization , analytical chemistry (journal) , ionization , ion , organic chemistry
In a sphingomyelin‐enriched sample of polar lipids frombovine milk, molecular species of intact sphingomyelin were separatedby normal‐phase high‐performance liquid chromatographyand detected by mass spectrometry (MS) for structuralinformation. First, by using electrospray with positive ionization(ESI), protonated molecules([M+H] + ) were detected.Second, in atmospheric pressure chemical ionisation(APCI+), in‐source fragmentation ofsphingomyelin ions led to the formation of ceramide ions. With theceramide ions as precursors, ions representative of both thelong‐chain base (LCB) parts and the fatty acid(FA) parts were detected in APCI‐MS/MS viacollision‐induced decomposition (CID). Using thisprocedure, it was possible to determine the sphingomyelin molecularmasses using ESI+ and then their respective LCB–FAcombinations(s) using APCI+‐MS/MS. At least36 protonated molecules of intact sphingomyelin were detected in thebovine milk sample. The combinations found covered a range ofmolecular masses from 673 to 815 Da. The 12 most common protonatedmolecules (constituting ∽90% of the total ion currentin ESI) were composed of at least 25 different LCB–FAcombinations. Saturated and unsaturated LCBs and FAs were detected inaddition to hydroxy fatty acids. The most common LCBs were 16:1, 17:1,18:1 and 19:1, whereas the most common FAs were 16:0, 22:0, 23:0 and24:0. LCB–FA combinations of sphingomyelin from bovine brian,bovine erythrocytes and chicken egg yolk are also presented. ©1998 John Wiley & Sons, Ltd.