Preparation method of eicosapentaenoic acid ethyl ester

A preparation method of eicosapentaenoic acid (EPA) ethyl ester, comprising:

• step (1), performing degumming and deacidification on a sardine crude oil to obtain a semi-refined sardine oil;
• step (2), performing esterification on the semi-refined sardine oil to obtain an esterified sardine oil, and then performing winterization on the esterified sardine oil to thereby obtain a semi-refined esterified sardine oil;
• step (3), performing bleaching and deodorization on the semi-refined esterified sardine oil by vacuum distillation, and collecting heavy phase components and light phase components individually;
• step (4), performing a first-stage distillation on the heavy phase components obtained in the step (3) in a molecular distiller with a distillation temperature in a range of 70˜80 degrees Celsius (° C.) and a distillation pressure of 0.1 pascals (Pa), and collecting a first-stage fraction and first-stage heavy phase components;
• step (5), performing a second-stage distillation on the first-stage heavy phase components obtained in the step (4) in a molecular distiller with a distillation temperature in a range of 80˜90° C. and a distillation pressure of 0.1 Pa, and collecting a second-stage fraction and second-stage heavy phase components;
• step (6), performing a third-stage distillation on the second-stage heavy phase components obtained in the step (5) in a molecular distiller with a distillation temperature in a range of 90˜100° C. and a distillation pressure of 0.1 Pa, and collecting a third-stage fraction and third-stage heavy phase components, wherein EPA in the third-stage heavy phase components is greater than 60 wt %;
• and
• step (7), purifying the third-stage heavy phase components collected in the step (6) by using a liquid chromatograph to collect a fraction in each of minutes under respective EPA peaks, removing a solvent of the fraction collected in each of the minutes through vacuum distillation, and combining ones of the fractions collected in the respective minutes having EPA of greater than 95 wt % to thereby obtain the EPA ethyl ester.