a vaccuum assisted rotovap? Toluene does have quite high bp. so I am worried that in the rotovap, the meth freebase will distill off with the toluene?
so long as you are not pulling too low a vacuum you should be ok.
what type of pump are you using and what vacuum does it achieve?
Toulene bp - 110.6
What is freebase meths bp?
The boiling point of methamphetamine at atmospherical pressure is 209-210°C, so it is very easy to separate from toluene, as long as you do not use excessive vacuum and heat.