What is a volatile buffer?
I can guess that is a pH buffer in which one of the species is volatile.
A "normal" pH-buffer is a solution formed by comparable concentrations of both the weak acid and its conjugated weak base.
These concentrations warrant that upon addition of small amounts of strong acids or bases these would be neutralized entailing only a little change of ratio between the concentrations
If the buffer is " volatile ", that means that its weak base (e.g. ammonia,