If you wanted to identify the components of a liquid, could you heat it and analyze the steam?
https://en.m.wikipedia.org/wiki/Inductively_coupled_plasma#A...
Apparently, watching an Aussie with a backyard shed full of mysterious chemicals and reagents has me assuming that any mysterious, unmarked liquid that needs to be identified is probably explosive.
If you heat water and alcohol to 80°, measurements would indicate ~100% alcohol.
You won’t know the right temperature unless you know what substance it is.
Edit: I guess you might also have stuff which reacts below their vaporising temperature.
But working on a good dog interface is the way to go.