Chemistry and Physics Faculty Articles

Liquid Chromatography with Dual Parallel Mass Spectrometry and 31P Nuclear Magnetic Resonance Spectroscopy for Analysis of Sphingomyelin and Dihydrosphingomyelin: II. Bovine Milk Sphingolipids

Document Type

Article

Publication Title

Journal of Chromatography A

ISSN

0021-9673

Publication Date

4-6-2007

Keywords

Sphingomyelin, Dihydrosphingomyelin, Sphingolipids, Phospholipids, Mass spectrometry, APCI-MS, ESI-MS, Atmospheric pressure chemical ionization, Electrospray ionization

Abstract

Liquid chromatography coupled to atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry (MS), in parallel, was used for simultaneous detection of bovine milk sphingolipids (BMS). APCI-MS mass spectra exhibited mostly ceramide-like fragment ions, [Cer-H2O + H]+ and [Cer-2H2O + H]+, which were used to identify individual molecular species of BMS according to fatty acyl chain length:degree of unsaturation and long-chain base (LCB). ESI-MS was used to confirm the molecular weights of BMS species. Both sphingomyelin (SM) and dihydrosphingomyelin (DSM) molecular species were identified, with DSM species constituting 20% of BMS. Approximately 56 to 58% of DSM species contained a d16:0 LCB, while 34 to 37% contained a d18:0 LCB. Approximately 26 to 30% of SM species contained a d16:1 LCB, while 57 to 60% contained a d18:1 LCB. BMS species contained both odd and even carbon chain lengths. The most abundant DSM species contained a d16:0 LCB with a 22:0, 23:0 or 24:0 fatty acyl chain, while the most abundant SM species contained a d18:1 LCB with a 16:0 or 23:0 fatty acyl chain. 31P NMR spectroscopy was used to conclusively confirm that DSM is a dietary component in BMS.

DOI

10.1016/j.chroma.2007.01.108

Volume

1146

Issue

2

First Page

164

Last Page

185

Comments

©2007 Published by Elsevier B.V. All rights reserved.

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