Hello,
I have a methanol extract that I have let stand for 3 days, three times. I have evaporated the methanol and, just to be sure, mixed it with water and lyophilized it. Before performing HPLC, I want to remove nonpolar impurities, chlorophyll, and pigments from my extract using liquid-liquid extraction to prevent damage to the C18 column. My first question is: should I use ethyl acetate, chloroform, or hexane for this purpose?
For one of my samples, I washed it three times with ethyl acetate and even left it shaking overnight. For another sample, I sonicated it. The sonicated sample changed color, and the water volume of all my samples increased by about 10-15%. How can I remove the ethyl acetate, and would using the extract in this state without removal damage the C18 column during HPLC analysis?
Thank you.
using ethyl acetate for liquid-liquid extraction to remove nonpolar impurities, chlorophyll, and pigments from your methanol extract is a suitable choice. After extraction, you can remove the ethyl acetate through evaporation and reconstitute your extract in a suitable solvent for HPLC analysis to prevent potential damage to the C18 column.
In general, to remove nonpolar impurities from a methanol extract, you will need to use a solvent that is immiscible with methanol and can selectively dissolve nonpolar substances. One commonly used solvent for this purpose is diethyl ether.
The non polar impurities can not be removed is level is less
It's go with final product of methanol
Use hexane/acetonitrile liquid/liquid extraction. Fat will be in hexane layer while your more polar compounds stay in acetonitrile.
Generally speaking,to remove nonpolar impurities from a methanol extract, you would typically use a solvent that is immiscible with methanol and has a higher affinity for the nonpolar compounds. One common solvent for this purpose is a nonpolar organic solvent like diethyl ether or hexane...Remember to handle all solvents with care and follow proper safety precautions, including working in a well-ventilated area and avoiding contact with skin or inhalation of vapors. Additionally, ensure that the selected solvent is compatible with your compounds of interest and that it does not introduce any unwanted impurities.
in tube or vial sample add diethylether and good shaking, let it in freeze for hours and filtration (solvent is good and do not contains fates)
Dear Kadir,
you may also want to consult this miscibility matrix
https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/solvent-miscibility-table
According to this table chloroform may not work...but I do not have personal experience with this...
Good luck
Alfred
Chloroform
You can refer Bligh and dyer method or Folch extraction method to remove lipophilic part
Have you thought of using GCB? That should get rid of the non-polar impurities . it could be done as a dispersive or in column format.
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Climate Science
- Climate Change