I work with air-sensitive organometallic compounds When I was in graduate school, we used to send off samples for x-ray crystallography in ampules that we would seal using a little apparatus. It was essntially a screw cap with a hole and an o-ring that you would put around the ampoule. That would then screw onto (I think) a threaded glass adapter with a ground-glass joint on the other end that you would put a gas inlet onto. All of this could be done in the glove box, then brought out and put on the Schlenk line. I seem to remember pulling a slight vacuum before sealing it. I'm guessing this was so the gas inside wouldn't expand and blow the seal out when flame sealing the ampoule.
I have tried to find an apparatus like this to order either intact or piece-by-piece (I have plenty of gas inlets), but I just can't seem to find the glass piece and the screw-down o-ring closure!!! Can anyone help me, please?
Hi Cameron,
Here's what I've been using for sealing NMR tubes:
https://www.wilmad-labglass.com/ProductList.aspx?t=446
You can also get ampules glass-blown onto 14/20 joints an use that.
A simpler approach would be to use thick rubber tubing between a closable 180 joint and the ampule. Set it up in the glovebox, bring out and then flame seal on the line.
Kyle
the valve you're looking for is a Cajon fitting from Swagelok. A quick search of their website did not turn anything up but you are looking for o-ring fittings. One side of this is correct. The glass piece is usually a ground glass stopcock terminating in 1/4" OD glass.
I actually stumbled on this page becasue I am trying (with little success) to seal my air sensitive samples in ampules using this exact fitting. I literally just got back from Lowe's with a small hand torch for finer control. wish me luck.
This! the Ultratorr union fitting. https://www.swagelok.com/downloads/webcatalogs/EN/MS-01-32.PDF
https://www.swagelok.com/en/catalog/Product/Detail?part=SS-4-UT-6