ABSTRACT
Introduction Some classes of lipids are large molecules that are not sufficiently volatile to allow gas-phase analysis by means such as gas chromatography (GC). Often, non-volatile lipids can be saponified to remove the fatty acid chains and these can be derivatized to yield volatile molecules, such as fatty acid methyl esters (FAME), pyrolidides, picolinyl esters, and others. These derivatives may be readily analyzed by gas chromatography in combination with a variety of detectors, including mass spectrometry. FAME analysis by GC with flame ionization detection (FID) is a common analytical method that provides valuable information regarding the net fatty acid chain composition of a sample. However, GC of FA derivatives can provide only an approximation of the composition of the original intact molecules. If there is non-random distribution of the FA chains in the parent molecules, FAME analysis can provide no indication of the distribution of those chains on the original molecules. It is preferable to analyze the large lipid molecules intact.
