The invention relates to the technical field of
chemical separation, in particular to a method for extracting
eicosapentaenoic acid and
docosahexaenoic acid by taking
fish oil or algal oil as a
raw material. The method specifically comprises the following steps: extracting a
fatty acid mixture obtained by taking crude ester type
fish oil or crude ester type microalgae oil as a
raw material by taking a ternary dual-
system compound
solvent consisting of a
metal ion solution and a
deep eutectic solvent as an extracting agent to obtain
eicosapentaenoic acid and
docosahexaenoic acid; wherein the eutecticevaporate
solvent is a degradable
biomass-based green natural eutecticevaporate
solvent, and the volume ratio of the
metal ion solution to the eutecticevaporate solvent is 0.05-3. According to the method, the
metal ion complexing extraction agent with the highest yield is compounded with the degradable environment-friendly green eutectic solvent to serve as the extraction agent of the EPA and the DHA, high-selectivity extraction can be conducted on the EPA and the DHA in the
fish oil or the
algae oil, the preparation process is safe and simple, the condition is mild, the period is short, the cost is low, the yield is high, the product purity is high, and the method is suitable for industrial production. Good industrial production application prospects are realized.