Tuesday, December 12, 2006

Identifying old NMR solvents (in Cambridge, UK)

When I was still messing around in Cambridge I one day happened to walk into the NMR service room at the perfect time. Dudley Williams had retired and was giving his stuff away and the NMR guys had this big box of NMR stuff they wanted to get rid of. The box was jammed full of deuterated solvents, NMR tubes and shift reagents so I grabbed the whole thing and took it back to the cave. However, not all of the solvents were easily identifiable. There was a large number of ampoule's with no label on them. They did however have some interesting colour codes happening. After a quick trip back to the NMR room it turned out that Cambridge used to have its own colour coding system for deuterated solvents. Here's a selection of ampoule's and what they contain:
The Cambridge NMR service web page used to have a guide to this colour coding. However, not anymore as most of these old ampoule's are gone by now. That was probably a bit premature since there are still quite a few of these ampoule's floating around. I talked the NMR guys into sending me the old colour chart so I could post it here. So to all you Cambridge people scratching your heads in bewilderment here's the answer to all your problems:
D!

4 comments:

yepyep said...

And now the obvious question. Why did they use colour coding instead of writing what's actually in the ampoule? NMR wasn't a big enough mystery, so they wanted to make it a little bit more difficult?

Steve said...

Our vials, your old ones, are a little different. The orange top (labeled red) is dichlormethane d2 and the pink top (labelled ???) is acetone d6. Personally, I still ignore the chart and enjoy playing the random solvent game.

Ψ*Ψ said...

My guess: the colored tops were more indelible than a label. How many times have you seen a half-torn-off illegible sticker on a vial in the lab? And it's solvent, so getting Sharpie ink off is no trouble.
Just my $.02...

Bunsen and Beaker said...

So Sharpies are like the worldwide universal marker? Thought so...

Our group has once received empty ampules of CD3OD. Doing NMR with a gas as a solvent would be weird. I wonder if that's possible. If it is, I chose D2! Anyway, more than likely it's all escaped, which brings me to my point, unidentifyable solvent is better than no solvent at all :)

-Beaker