What to do with samples that cannot crystallize？

01 Condition of sample

Fish oil is an unsaturated fatty acid (mainly EPA and DHA) extracted from the body of deep sea fish. It is yellow oily liquid with good stability, but it is easy to be oxidized and stored at low temperature to avoid light and oxygen. It is easily soluble in organic solvents such as ethanol and methanol, but insoluble in water.One of the unsaturated fatty acids, EPA, has been established to have medical benefits and does not crystallize.

02 Solution

Generally, EPA content in pretreated fish oil ranges from 30 to 40%. DHA and EPA are similar in structure and cannot be separated well by common chromatography. It is proposed that EPA and DHA in fish oil with low content can be separated by continuous chromatography with high separation efficiency, and the purity of EPA above 98.5% can be obtained.

03 Raw material spectrum analysis

Detection method Instrument: waters 2695-2996

Chromatography column: ODS-2 5um 4.6*250mm 

Mobile phase: Acetonitrile 90%- water 10%

Fish oil sample liquid chromatogram detection diagram The purities of EPA and DHA were 43% and 32%, respectively

04 Methods for screening and purification of fillers

We tried to use polymer, gel resin, C18, C4, C30 and other fillers, among which C18 filler has a better separation effect on EPA and DHA in fish oil.

Continuous chromatograph separation of high purity EPA fish oil alone groping process :

Instrument: EMP0010-EUD2000

Chromatography column: C18（10μm） 10*250mm Mobile phase:Methanol 88%- water 12%

Elution flow rate: 3ml/min 

Sample volume: 1 %

Simulation curve of single-column separation degree

According to the single column experiment, the operation conditions of continuous chromatography were set and the samples were tested after extremely stable operation.

05 Purification results

Through the continuous chromatography process, we increased the content of the sample from 40% purity to more than 98.5%, removed most of the impurities in the sample, the yield of more than 80%, and finally obtained high content of EPA fish oil.