Aim: Characterization of phosphatidylcholines (PCs) and lysophosphatidylcholine in human plasma using LC-IT-MSn. The characterization approach was based on trapping the eluted positive ions and applying low voltage for fragmentation to MS2 and further fragmentation of the most abundant two peaks to obtain MS3. This approach allowed linking the MS3 data to MS2 and precursor ion. Methodology: The fatty acid part, at sn-1 and sn-2 of the glycerol backbone, could be identified based on the favored cleavage pathway. Conclusion: The dysregulated PCs and lysophosphatidylcholines in human plasma obtained from acute coronary syndrome cases, and Type 2 diabetes patients suffering no coronary syndromes were estimated and matched versus healthy volunteers. An epoxide form of 16:0-18:2 PC was confirmed, m/z 774.6.
Keywords: Type 2 diabetes; acute coronary syndrome; biomarker; fragmentation pathway; high-performance liquid chromatography; ion trap mass spectrometry; lysophosphatidylcholine; oxidized phosphatidylcholine; phosphatidylcholines; triple quad mass spectrometry.