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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: c0ok1e on March 19, 2010, 04:01:29 AM

Title: Column chromatogrpahy for acidic, polar compound. Which is better?
Post by: c0ok1e on March 19, 2010, 04:01:29 AM

I will use column chromatography to seprate my compound which has the characteristic polar and acidic. Which column is recomended? I have thought of using c18 column or sephasex lh20 column but cannot decide which will be more suitable. Are there any other better options?

Title: Re: Column chromatogrpahy for acidic, polar compound. Which is better?
Post by: marquis on March 19, 2010, 08:01:24 PM

Try application notes put out by the column manufacturers.  They are usually a good starting point.  Also, your column manufacturer often has technical assistance lines.
It is a good idea to try them, if possible.

Good luck.

Title: Re: Column chromatogrpahy for acidic, polar compound. Which is better?
Post by: Cesium-137 on February 13, 2011, 08:45:00 PM

I'd go with C18 or C8 or something. Sephadex is better for size exclusion, and might end up trapping your product inside it. Reverse phase is good if your compound is water soluable, which it sounds like it is.

Title: Re: Column chromatogrpahy for acidic, polar compound. Which is better?
Post by: Camus023 on March 24, 2011, 10:56:48 AM

acoding my exprience
ODS C18  is better than sephadex  to separate polar compoud
but you must kown that:
elute solvent usually contain water, so your compoud should not degradate in water
meanwhile, it need use toluene to

above all
Reversed-phase  C-18  have less resolution to normal  phase silica

If this product is only a litter, in my opinin ,you had better use  preparative  HPLC for separation

Title: Re: Column chromatogrpahy for acidic, polar compound. Which is better?
Post by: bunky on July 11, 2011, 10:58:41 PM

Don't be spoiled by HPLC.

You can use up to 20-30% iPrOH in DCM/CHCl3 without dissolving silica.  Used it for rhodamines and fluoresceins.