Comparative determination of fatty acid composition of low-molecular components of blood plasma by three mass spectrometry techniques: the 'old-new' exercise in lipidomics

摘要

Fatty acid composition of lipid low-molecular components of human blood plasma was determined by the combination of three analytical techniques: gas chromatography mass spectrometry and electrospray high-resolution mass spectrometry/tandem-mass spectrometry with direct flow injection. More than two tens of volatile fatty acid methyl esters were identified in lipid extracts subjected to methanolysis. When direct injection electrospray mass spectrometry was employed, 21 lysophosphatidylcholines and 25 phosphatidylcholine small isomer groups were recognized. Fatty acid distributions over the analytical signal intensity in groups of methyl esters and lysophosphatidylcholines were demonstrated to be similar to each other and highly correlated. The fatty acid distribution for phosphatidylcholine was correlated to those to a lesser extent. At the same time, the analytical signal intensity of lysophosphatidylcholines and phosphatidylcholines was observed to be highly correlated to concentrations of these lipid compounds in blood plasma determined by the similar technique of direct injection mass spectrometry and available in the literature.