Metabolic Profiling of Aliphatic, hydroxy, and Methyl-Branched Fatty Acids in Human Plasma by Gas Chromatography–Mass Spectrometry

ABSTRACT

An efficient method for the simultaneous profiling analysis of 44 fatty acids including 24 aliphatic, 12 hydroxyl, and eight methyl-branched fatty acids as tert-butyldimethylsilyl (TBDMS) derivatives was developed by gas chromatography–mass spectrometry. In this study, new mass spectral databases of isolauric, 11-methyllauric, isomyristic, isopentadecylic, isopalmitic, isostearic, 17-methylstearic, and 19-methylarachidic acids were constructed as TBDMS derivatives. Under the optimal conditions, linearity in the range of 0.1–10.0 µg/mL (24 aliphatic fatty acids) and 0.01–1.0 µg/mL (eight methyl-branched and 12 hydroxy fatty acids) showed good correlation coefficients (r ≥ 0.997). The repeatability showed relative standard deviation of less than 11.2% and accuracy (percent relative error) varied from −11.0 to 7.8 for the 44 fatty acids studied. The recoveries ranged from 61.7 to 90.1% with good repeatability. When applied to human plasma sample, 18 aliphatic, three 2-hydroxy, three 3-hydroxy, and five methyl-branched fatty acids were positively identified and quantified. Therefore, the present method will be useful for profiling analysis of various fatty acids in biological samples including plasma.

KEYWORDS:

• Aliphatic fatty acid
• gas chromatography–mass spectrometry
• hydroxy fatty acid
• methyl-branched fatty acid
• tert-butyldimethylsilylation

Additional information

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science, ICT & Future Planning (2015R1A4A1041219), the Ministry of Education, Science, and Technology (2015R1D1A3A01016103) and by Suncheon Research Center for Natural Medicines.