Preparative separation of algal polar lipids and of individual molecular species by high-performance liquid chromatography and their identification by gas chromatography—mass spectrometry

✍ Scribed by Tomás Řezanka; Miloslav Podojil

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 863 KB
• Volume: 463
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)84492-7

✦ Synopsis

A crude polar lipidic extract of the green fresh-water alga Chlorella kessleri cultivated under heterotrophic conditions was separated by high-performance liquid chromatography (HPLC) on a preparative silica gel column into a total of twelve lipid classes, in which the content of fatty acids was determined by means of gas chromatography-mass spectrometry (GC-MS). The separation was by gradient elution from hexane-isopropanol (6:8) to hexane-isopropanol-water (60:80:14) lasting 20 min and then isocratically for 30 min. A total of 17.5 mg of lipids were injected. Individual types of lipid classes were further separated into eighteen molecular species by isocratic HPLC on a reversed-phase C1 s column using a mixture 20 mA4 choline hydrochloride in methanol-water-acetonitrile (90.5:7:2.5) in the preparative mode (5 mg injected). Phosphatidylcholine and phosphatidylethanolamine were hydrolyzed by phospholipase C and corresponding diglycerides were identified by GC-MS on a polar capillary column. In mono-and digalactosyldiglycerols, fatty acids in position 1 were identified after a specific hydrolysis by lipase. The recovery obtained with an UV detector in HPLC and a mass spectrometer in GC-MS is discussed. It was shown that the relative response of the UV detector decreases with increasing saturation of acids, whereas the relative response of the mass spectrometer increases.