| abstract |
The purpose is to economically obtain highly unsaturated fatty acid derivatives of high purity and good quality. Provided is a method for acquiring highly unsaturated fatty acid derivatives by bringing a mixture of fatty acid derivatives into contact with an aqueous silver salt solution, with the free fatty acid content in the aqueous silver salt solution being less than 0.2 meq per 1 g silver when the method is performed using the aqueous silver salt solution repeatedly. |