Improved high-performance liquid chromatographic method for the separation and quantification of lipid classes: application to fish lipids

An improved straight-phase HPLC method for the separation and quantification of lipid classes is described. Two binary gradient solvent systems were used, one for polar and one for neutral lipids, and detection was performed with a light-scattering detector. The developed HPLC methods were highly reproducible and allowed base-line separation of all investigated polar lipid classes (phosphatidic acid, diphosphatidylglycerol. phosphatidylethanolamine, phosphatidylcholine, sphingomyelin, phosphatidylserine, phosphatidylinositol and lysophosphatidylcholine) and neutral lipid classes (triacylglycerol, free fatty acid, diacylglycerol, cholesterol and monoacylglycerol) except of cholesterol ester and wax ester. Application of the chromatographic systems demonstrated that the methods are suitable for quantitative analysis of the major lipid classes present in lipid extracts from livers and eggs of Atlantic salmon (Salmo salar).