Structural analysis of isolated components in microalgal lipids: Neutral lipids, phospholipids, and glycolipids

Microalgal lipids are important feedstock for alternative liquid biofuels. The composition and molecular structure of lipids affect physicochemical properties of obtained liquid biofuels and rational design of composite catalysts during catalytic conversion. However, there is still short of detailed information on composition of microalgal lipids. In this study, neutral lipids, phospholipids, and glycolipids were isolated and analyzed via ultra-high performance chromatography and high-resolution mass spectrometry. A total of twenty-five compounds had been identified via the special information of the mass-to-charge ratio m/z, including fifteen kinds of neutral lipids, four kinds of phospholipids, three kinds of glycolipids, and three kinds of sphingolipids. The main cracking mechanism of these compounds during pyrolysis were cracking of fatty acid chains (C16, C18, and C20) from backbone of glycerol, forming different distributions of low molecular species. Monosaccharide such as glucose, amide group, and phosphate group were also typical structures in microalgal lipids.