I need to run a column using Dowex 50. I did it once but i m unsure about its reuse. If it can be then how can we reactivate dowex 50. I tried doing it by ethanol but i am not getting the proper result. Kindly help me
8/14/15
Dear Somya,
Yes, you can certainly re-use Dowex 50, as well as other ion exchange resins. This is good to know how to do, as resins are pretty expen$ive.
Again, more information is needed. If the resin has been used, in what form is it now in? And to what form do you want to convert it? To re-activate the resin, you need to displace (remove) the unwanted ion(s) and replace them with the desired ion. Washing w/ ethanol will not do this. If you used the resin for desalting purposes and it now has cations, e.g., Na+, K+, etc and you want to put in back in the hydrogen (H+) form, pour the resin into a suitably-sized column and irrigate the resin with acid (~1 M) such as HCl or H2SO4. you may have to run 1-2 bed volumes through the resin to displace all the cations and completely restore the resin to the H-form.
If the resin is in the H-form, and you want to replace it with, e.g., Na+, K+, NH4+, etc., then irrigate the resin in the column with ~1 M solution of the cation of choice, e.g., NaCl, KCl, NH4Cl. As the solution passes thru the resin, the cation of choice will displace H+ from the resin and the column eluent will become acidic. This you can monitor w/ pH paper. Keep irrigating the resin until the pH is no longer acidic, at which point the resin will have been reactivated.
I would suggest you try going on BioRad's website. They make many different kinds of resins. I've purchased and used their resins in the past. Their resins come supplied w/ some literature describing how to convert the resin from one ionic form to another. I believe this information is now available on their website from which you can download it. BioRad makes AG 50W-X8, which is a strong cation exchange resin that is the equivalent of Dowex 50. Instructions for regeneration of AG-50W should work for Dowex 50. See the attached file. Bio-Rad is pretty good at giving technical assistance over the phone. I have done this a number of times.
I hope this helps you. If you need more information, let me know.
Bill Colonna Iowa State University, Ames, IA USA [email protected]
Is there any reason why 5-10 vols of 2-5N NH3 would fail to elute some metabolites?
" Is there any reason why 5-10 vols of 2-5N NH3 would fail to elute some metabolites? "
1) Yes. Various types of interactions with matrix
2) You destroyed your molecules
Nazanin Behrooz Hello
Dow Resin Nomenclature:
The nomenclature used to identify DOWEX™ fine mesh resins is designed to communicate specific information regarding resin type and degree of cross-linkage. There are three resin types: strong acid cation exchange resins designated as “50W”, Type I strong base anion exchange resins designated as “1”, and Type II strong base anion resins designated as “2”.
Under the Dow nomenclature, one of these three designations appears in conjunction with an “X” number describing the degree of resin crosslinkage (the X number is the percentage of divinylbenzene [DVB] in the resin copolymer). Therefore... DOWEX 50WX8 is a strong acid cation resin containing 8% DVB. DOWEX 1X4 is a Type I strong base anion resin containing 4% DVB.
Best regards
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