Industrial high-performance liquid chromatography purification of docosahexaenoic acid ethyl ester and docosapentaenoic acid ethyl ester from single-cell oil

Abstract

The use of polyunsaturated fatty acids (PUFA) as medicine or in functional diets requires high purity. An industrial purification method for PUFA from Schizochytrium sp. SR21 oil was investigated. This oil contains fewer unwanted components than fish oils. Docosahexaenoic acid and docosapentaenoic acid ethyl esters (DHA-E and DPA-E) were prepared by treatment of this oil with ethanol and 1 N potassium hydroxide in hexane. DHA-E and DPA-E were purified by an industrial high-performance liquid chromatography (HPLC) plant. The separation plant consists of two columns (400 mm i.d, 1,000 mmL) with temperature-controlled water jackets and double-plunger (four heads) injection and eluent pumps. This plant was computer-controlled and equipped with an explosion-prevention system. The packed material was octadecylsilica (reverse-phase ODS), and the eluent was methyl alcohol/water (98:2). DHA-E and DPA-E from single-cell oil were highly purified by this industrial HPLC method in a onestep process. The DHA-E and DPA-E obtained were better than 99% purity.