Is there really an advantage in using 99.9% isopropanol vs. the 91% solution that is readily available? A 91% v/v solution is the azeotrope. A nearly pure solution would be somewhat more volatile but temperature and air flow are probably a lot more important than that slight difference. I wonder how much moisture the anhydrous stuff absorbs before it evaporates?
Anhydrous isopropanol costs $10 for a 500ml bottle at digikey, not including shipping. The other day I walked down to the local drug store and bought a 480ml bottle of 91% isopropanol/water for under $3.
Or does it make a noticeable difference?