I have worked a lot with dimethylacetamide which does pick up water over time. My experience with DMF is not as extensive but they should have pretty similar hydroscopic tendencies. I would guess the expiration date means it's no longer 100% DMF. It's fine as an organic solvent as it sits unless water is a problem.
-Carole
"Simplicity involves unburdening your life, and living more lightly with fewer distractions that interfere with a high quality life, as defined uniquely by each individual." |
- Linda Breen Pierce
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**med.cornell.edu]On Behalf Of Brian & Erin Mueller
Sent: Tuesday, August 04, 2015 9:44 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] DMF "use within 5 years"
As I recall, DMF is pretty hydroscopic. A quick web search yielded: "DMF is stable. It is hygroscopic and easily absorbs water form a humid atmosphere and should therefore be kept under dry nitrogen." Perhaps that is why they put an expiration date, after opening.
Brian Mueller
Lab EHS Consultant
303-819-8422
From:"Margaret Rakas" <mrakas**At_Symbol_Here**SMITH.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Sent: Tuesday, August 4, 2015 9:30:03 AM
Subject: Re: [DCHAS-L] DMF "use within 5 years"
If it's 'molecular biology grade'--whatever that is--sometimes they have use-by dates for reagents with this labeling. I've had buffered phenol and even ethanol that have been unopened but the molbio people see the 'expiration' date and hazwaste it...
good luck and let us know (you could also call Acros)--
Margaret
On Tue, Aug 4, 2015 at 11:25 AM, Stuart, Ralph <Ralph.Stuart**At_Symbol_Here**keene.edu> wrote:
During a lab inspection today, I noticed a bottle of extra pure Dimethylformamide in one of our labs that had a note on the manufacturers (Acros) label that says "use within 5 years of opening". A little Google searching doesn't seem to indicate the DMF is a peroxide former, so I wonder if anyone can shed some light on why this time limit is recommended?
The bottle was received in Jan 2011, so inquiring miles would like to know.
thanks for any insight on this.
- Ralph
Ralph Stuart CIH
Chemical Hygiene Officer
Keene State College
Keene, NH. 03431
ralph.stuart**At_Symbol_Here**keene.edu
--
Margaret A. Rakas, Ph.D.
Manager, Inventory & Regulatory Affairs
Clark Science Center
413-585-3877 (p)
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