[Object] A fatty acid-related polyunsaturated compound can be selectively purified using an industrially operable successive method under moderate conditions.
[Content] A highly purified fatty acid-related polyunsaturated compound is obtained by a process comprising steps of forming a complex with silver on account of the high degree of unsaturation of the fatty acid-related polyunsaturated compound, isolating the complex from other fats on account of the hydrophilicity of the complex and then applying dissociating procedures to the complex to obtain the fatty acid-related polyunsaturated compound as a target substance on account of the hydrophobicity of the fatty acid-related polyunsaturated compound. As to the procedures for dissociation, addition of a dissociating agent and reduction of silver are disclosed. As to the dissociating agent, various compounds which produce insoluble composition with silver other than water are disclosed. Furthermore, an apparatus appropriately used to carry out this method is also disclosed.