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.
