Sciencemadness Discussion Board

storage under nitrogen

CouchHatter - 9-1-2019 at 19:19

Today I realized I'm not storing my THF properly. Furthermore I do not know if it has BHT in it. I don't want to wait around to find out.

I see 'store under nitrogen' a lot, but am not too familiar with Schlenk technique. What I do know of it deals with apparatus, not storage containers. If I quickly unplug and then cap it after purging and filling with nitrogen repeatedly, is that enough to prevent peroxide formation? The positive pressure from the cylinder would probably be too much for a PP bottle, yet this advises against storing stuff like THF in threaded glass. Do I have to use a ground stopper?

I have a manual aspirator, a couple gas bubblers, 24/40 gas outlet, tubing and PP valves, and a vacuum pump. I'm not opposed to eventually getting a bona fide Schlenk line for more complex syntheses, but for now I'm looking for a more amateurish solution to a single problem. Maybe all this trouble is why they concluded to replace it after 12 months, or avoid working with it altogether.


Attachment: UCCS.LS Appendix I Peroxide Management.pdf (205kB)
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MrHomeScientist - 10-1-2019 at 06:42

I store my lithium metal under argon, and all I did was put the gas outlet tube in the bottle, purged for a few minutes, wrapped the bottle threads with gastight plumber's Teflon tape and screwed the cap on tightly. There's been no noticeable corrosion for almost a year.
When purging like this, remember the magic number 7: measure your gas flow rate and container volume, and let it run long enough to replace 7 volumes worth of gas. This ensures all the air is replaced.