I have a fraction that i got from Vacuum liquid chromatography with ethyl acetate:ethanol:water (100:26:1). The fraction contains of coumarin in a low Rf value (checked on tlc), so i decided to run column chromatography. I assumed that the coumarin has high polarity because i already tried in non polar mobile phase but didnt work. So, could you please help me for polar/very polar mobile phase for CC?except BAW of course...thanks.
Dear Alik Kandhita Febriani
For column chromatography to separate coumarins, I prefer to use a gradient of mixtures started with 1:9 and ended to 9:1 of ethyl acetate: ether. Generally, coumarins except their glycosylated derivative are not highly polar.
All the best
Probably you askabout reversed phases?
Start with 5-10% AcCN with water. For polar analytes you could think about HILIC. Remember that best performance you will get for analytical separation mode that is orthogonal to the preparative one used to collect the fraction.
Regards
GB
Dear Alik Kandhita Febriani
For column chromatography to separate coumarins, I prefer to use a gradient of mixtures started with 1:9 and ended to 9:1 of ethyl acetate: ether. Generally, coumarins except their glycosylated derivative are not highly polar.
All the best
Coumarin should elute in a fairly non-polar solvent from silica gel. Are you sure you have coumarin? Or does the compound contain polar substituents?
What solvent system are you using for the TLC where you see coumarin?
In this reference, coumarin compounds run with fairly non-polar solvent systems:
https://books.google.com/books?id=fBCDK_Tgh10C&pg=PA389&lpg=PA389&dq=coumarin+TLC&source=bl&ots=5lp896QTZq&sig=ACfU3U3MH2Uix3p70-o-Bf62R5NuQLz_Rg&hl=en&sa=X&ved=2ahUKEwiN76T65pDrAhUBYawKHbQlC9U4FBDoATADegQICRAB#v=onepage&q=coumarin%20TLC&f=false
Dear Alik
Mobile phase : petroleum ether : acetone 100 : 5 (v/v). For more details, please look at the following below attached paper which may help you in your analysis.
Thanks
Dear Alik
Mixtures of hexane and ether or mixtures of hexane and ethyl acetate may help.
- Badges
- Science topic