Abstract: A method for producing an EPA alkyl ester-containing composition includes: preparing a raw material oil containing an EPA alkyl ester in an amount of from 50 to 92% by mass in the total fatty acids, in which a mass ratio of a DHA alkyl ester to the EPA alkyl ester contained in the raw material oil is 3.3% by mass or less and further a ratio of trans isomers in the EPA alkyl ester contained in the raw material oil is 2% by mass or less; bringing the raw material oil into contact with an aqueous solution containing a silver salt; recovering the aqueous solution containing the silver salt brought into contact with the raw material oil; bringing the recovered aqueous solution containing the silver salt into contact with an organic solvent; and recovering the organic solvent brought into contact with the aqueous solution containing the silver salt.

Abstract: A method for producing an EPA alkyl ester-containing composition includes: preparing a raw material oil containing an EPA alkyl ester in an amount of from 50 to 92% by mass in the total fatty acids, in which a mass ratio of a DHA alkyl ester to the EPA alkyl ester contained in the raw material oil is 3.3% by mass or less and further a ratio of trans isomers in the EPA alkyl ester contained in the raw material oil is 2% by mass or less; bringing the raw material oil into contact with an aqueous solution containing a silver salt; recovering the aqueous solution containing the silver salt brought into contact with the raw material oil; bringing the recovered aqueous solution containing the silver salt into contact with an organic solvent; and recovering the organic solvent brought into contact with the aqueous solution containing the silver salt.