Phospholipid composition of human blood plasma as detected by matrix-assisted laser desorption/ionization mass spectrometry: new observations
T14N2
B.L. Milman, N.V. Lugovkina, I.K. Zhurkovich
The dependence of matrix-assisted laser desorption/ionization (MALDI) mass spectra of lipids extracted from human blood plasma and corresponding lipid compositions on different experimental conditions was studied. Not only numerous compounds from groups of lysophosphatidylcholines (LPC) and phosphatidylcholines (PC) but also lipid oxidation products including six oxidized LPC, were detected. They were available in the original samples and also produced by the reaction with air oxygen molecules resulted in their accumulation in samples under analysis. A higher sensitivity of MALDI detection was observed for less hydrophobic LPC as compared to more hydrophobic PC and was explained. The hydrophobicity/lipophilicity factor was possibly revealed when the matrix of 2,5-dihydroxybenzoic acid has been replaced by α-cyano-4-hydroxycinnamic acid. The latter was rarely used in MALDI of lipids and may be suitable for the selective determination of LPC and oxidized LPC.
