Yes, sephadex LH-20 can be use to fractionate as well as purify fractions. It is also re-usable as it can be cleansed or washed by first flushing through with methanol, if very dirty then try washing with a solution prepared by dissolving 1 g of oxalic acid in 100 ml of methanol or a mixture of Dioxane/distilled water (1:3). Finally washed through with enough distilled water again to remove all traces of dioxane.

LH 20 is very versatile and can be used with many solvents. As for washing, I can't add anything to what was mentioned by Dr. Ajayi.

As you know, LH-20 can't be run fast or it gets "squished" and creates higher back pressure. It works well for fractionation (as seen in this app note purifying anthocyanins: http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN23_Self-pack_Column_Options_for_the_CombiFlash_Rf.pdf )

and it can be used for clean-up as demonstrated in this poster: http://www.isco.com/WebProductFiles/Applications/101/Poster_and_Paper_Reprints/Purification_of_Phenolic_Flavonoids.pdf

It can't really be used for gradients because it swells differently in different solvents. It it gets bigger in the column, it causes high back-pressure.

I meant, for very difficult to clean sephadex LH-20 column, dissolve 10 g (sorry not 1 g but 10 g) of oxalic acid in 100 ml methanol and use to soak (extract mostly difficult to remove plant dye or pigment) and remove all other dirt that may be there. Thanks and sorry for error in the weight of the oxalic acid to be used.

Dear Mudasir

i think it is possible but you can not use organic solvant to elute sephadex g 25. Lh 20 is a lipo and hydrophylic form. 

Dear Mudasir,

I apologise for just seeing your post. I agree with Ilias response to your question. In the case that you can not afford sephadex LH-20, you can still load your said fraction (sizeable quantity) on silica gel column again or better stll try prep-TLC.

Dear All,

Could you please share your experience?

 I need to purify a synthesized polymer from in its catalysts. The mixture (polymer with Mw 14k and catalysts with Mw 700) is soluble in Methanol. However, the catalysts are not soluble in water while the polymer is dispersed in it.

My enquires are;

1- Is Sephadex G-25 is the right choice for this separation? and suitable for this polymer Mw?

2- Can I use Methanol only as a mobile phase or I should prepare Methanol/Buffer 25/75 v/v? I read in the manual that they recommend 25/75 % v/v.

3- Shall I use buffer or distilled water is fine?

4- Is narrow or broad column recommended for this separation?

Best Regards

Respected Dr ajayi,

hope you are doing well. As you mentioned in your first comment that wash the column with water to remove dioxne. Here one question raise should we use 100℅ water to wash the column.?

Yes, you could.