Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/10/1998
Publication Date: N/A
Technical Abstract: Analysis of phospholipids was performed using a high performance liquid chromatographic separation coupled with two mass spectrometers in parallel providing electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) data simultaneously from a triple quadrupole instrument and a single quadrupole instrument, respectively. The output from UV Vis and evaporative light scattering detectors were also acquired by the two mass spectrometers, respectively, for four detectors overall. This arrangement was used to identify and calculate area percents for molecular species of dihydrosphingomyelin (DHS) and sphingomyelin (SPM) in commercially available bovine brain SPM, in human plasma extract, and in porcine lens extract. Commercially available bovine brain SPM was found to contain 11.5% DHS and 88.5% SPM. The only DHS molecular species identified in human plasma was 16:0-DHS, at or below 1% of the sphingolipid content. Porcine lens membranes were found to contain 14.4% DHS and 85.6% SPM. Other findings include: 1) phospholipids were found to undergo dimerization in the electrospray source, giving masses representing combinations of species present; 2) triacylglycerols gave ammonium adducts as base peaks in their APCI mass spectra, which reduced fragmentation and increased the proportions of protonated molecules; and 3) mass spectra were obtained for phospholipids which underwent protonation and sodium adduct formation in different chromatographic runs.