High performance liquid chromatographic separation of omega-3 fatty acid esters derived from fish oil sources

Initial interest in omega-3 fatty acids was precipitated by results of studies performed on populations of Greenland Eskimos. These people experienced a low incidence of death due to ischaemic heart disease compared to Western populations. Epidemological studies attribute this low mortality rate and other health benefits to a diet high in omega-3 fatty acids. The major fatty acids of interest are the polyunsaturates, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which occur naturally at high concentrations in the body oils of cold water fish. Various clinical studies have been performed using dietary supplements of fish liver oil or whole body fish oil concentrates to investigate the role of EPA and DHA in the reduction of plasma triglyceride and cholesterol levels, the prevention of thrombosis and artherosclerosis, the inhibition of tumor growth, and their effect on many other health disorders. However, there is controversy over the therapeutic value of fish oil supplements. There is an obvious need for easily accessible, inexpensive sources of pure or highly enriched EPA and DHA to be used to investigate the nutritional and biochemical effects, separately and synergistically, in human and animal studies at various dosage levels. Thus, the focus of this research is the development of the separation of high purity EPA and DHA as their ethyl esters on a preparative scale from commercially available dietary fish oil supplements. Optimal separations of fish oil fatty acid esters on the analytical, semi-preparataive and preparative scales are described. Preparative scale isolations yielded EPA and DHA ethyl esters with purities of 97.7% and 93.7%, respectively