1) Extraction: take by weighing 200kg minced tuna liver, add 400kg ethyl acetate, stir, extract for 80 minutes, get the ethyl acetate layer; use 240kg ethyl acetate to extract again for 80 minutes, get the ethyl acetate layer; merge, Prepare ethyl acetate extract phase 625L;
2) Salting out: add 125L saturated Na2CO3 to the ethyl acetate extraction phase, adjust the pH to 8, stir for 5 minutes, and let stand for 0.5h;
3) Pickling: After washing three times with 0.1NHCL, add Na2SO4 according to 1kgNa2SO4/50L ethyl acetate, overnight;
4) Distillation: At 40-50°C, distill and concentrate for 10 hours to obtain 40L of fish oil; at 85°C, rotary evaporation for 12 hours to obtain 5.3L of crude fish oil;
5) Acetone refinement: add 10L of acetone to the crude fish oil, mix well, let stand at 0-5°C for 2.5 hours, filter, distill and concentrate the filtrate to obtain 4.7L of fish oil;
6) Molecular distillation: The fish oil obtained in step 5) is subjected to secondary molecular distillation, wherein, the first molecular distillation, the low temperature is 80°C, the high temperature is 170°C, and the distillation is 8h; the secondary molecular distillation, the low temperature is 80°C, and the high temperature at 195°C, distilled for 9 hours to obtain 4.3L of fish oil;
7) Column chromatography: Dissolve the fish oil prepared in step 6) in 4.3L of ethyl acetate, and then process it in a glass chromatography column, take the ethyl acetate chromatography, distill and concentrate to obtain Pure Cod Liver Oil 4L.
8) Separation by freezing: the fish oil prepared in step 7) was frozen at 5° C. for 5 hours, and filtered with a plate and frame filter press at 5° C. to obtain 3.9 L of Pure Cod Liver Oil.
