Modern analytical methods are very impressive. High resolution mass spectrometry that directly gives you the elemental composition is crazy, but that is nothing unusual today.
Of course NMR could show all the information you need here and more, as they used it to confirm the conclusion. But it needs comparatively massive amounts of sample, having to run a 100g reaction to get enough substance is though. But if you're going after a 0.06% side product you're dealing with tiny amounts most of the time.
This works for deuterium to hydrogen, but only barely (0.06%!). And that's a 2:1 mass ratio. Uranium separation is 238:235, roughly, or 1.013:1. Not so easy!
0.06% is the deuterium impurity in the product, not HPLC yield. Getting 6mg from 100g means their separation was almost perfect. But I agree it's probably harder with uranium.
I wonder how stable this thing is, or if it can even be all that reliably purified out (if anyone wanted to). I've heard from reliable-ish sources that when tritium is introduced to the body it diffuses throughout quite rapidly, so I'm guessing it might be impossible to get rid of this with any reasonable level of effort.
Of course NMR could show all the information you need here and more, as they used it to confirm the conclusion. But it needs comparatively massive amounts of sample, having to run a 100g reaction to get enough substance is though. But if you're going after a 0.06% side product you're dealing with tiny amounts most of the time.
I wonder how stable this thing is, or if it can even be all that reliably purified out (if anyone wanted to). I've heard from reliable-ish sources that when tritium is introduced to the body it diffuses throughout quite rapidly, so I'm guessing it might be impossible to get rid of this with any reasonable level of effort.