Dry silica gel is always easy to remove from the column as compared to wet silica gel. Maximum glass columns break/crack during the silica gel removal process, also, the glass
columns are expensive.
For normal column, where 60-120 mesh size silica gel is used, generally the gravity method will work to remove eluent solvent; however, 200-400 mesh silica gel column (flash
chromatography) slight nitrogen pressure is needed to remove the excess solvent from the surface of silica gel. Never use
uncontrolled pressure for eluting the column. Use a proper regulator to control the pressure inside the column.
Therefore, it is prudent practice to dry the column before transferring the used silica gel into a waste container to avoid extra work and solvent exposures.
References:
1.
Still, W. C.; Kahn, M.; Mitra, A. J. Org. Chem.
1978, 43, 2923.
2.
Ponten, F.; Ellervik, U. J. Chem. Educ. 2001, 78, 363.
3.
Bell, W. L.; Edmondson, R. D. J. Chem. Educ. 1986, 63, 361.
4.
Thompson, W. J.; Hanson, B. A. J. Chem. Educ. 1984, 61, 645.
5.
Friedel, M. G., Berteau, O, Pieck J. C., Atta M, Ollagnier-de-Choudens S, Fontecave M, Carell T.
Chem. Commun., 2006, 445.
Tilak
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
On Behalf Of Melinda Box
Sent: Wednesday, October 09, 2019 3:36 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: [DCHAS-L] is drying chromatography media in open cans ok?
Hi, all,
I am searching for alternatives on behalf of a research group whose current practice is to invert columns with wet chromatography media over old shipping cans in fume hoods. The issues are:
Any alternatives you've encountered or experiences with environmental inspection verdicts on these would help immensely.
Thanks,
Melinda Box, M. Ed.
Organic Chemistry Lab Supervisor
Chem Dept Safety Officer
North Carolina State University
Department of Chemistry
Fox 328
Tel: (919) 515-2537
--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at
membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas
Previous post | Top of Page | Next post