Today, I had reason to purify a small amount of l-ephedrine freebase, for use as a reference standard for crystal structure, and melting point test, this was extracted from OTC nasal drops, which consist of ephedrine hydrochloride at a concentration of 0.5% by weight of the aq. solution, chlorobutanol, and NaCl, extracted via basification.
I expected the ephedrine to precipitate out and form a layer of the oily freebase in the bottom of the test tube being used, upon addition of 6ml of concentrated NaOH solution however, copious evolution of a scentless, colorless, and nonflammable gas was observed, with effervescense of the ephedrine solution, which did not ppt out as an oil layer, but had to be recovered by shaking with petroleum ether, and is waiting to be evaporated (as I am tired and lazy, so cannot be bothered to do it right away, ahh the joys of having next to no responsibillities
)
The gas definately couldn't have been chlorine, as it was colorless and odorless, not oxygen, as the glowing splint test proved negative, nor hydrogen, as it did not give the charcteristic pop sound on ignition of the mouth of the test tube after being covered with a finger, the whole reaction was slightly exothermic, enough to make the test tube warm to the touch.
Any ideas as to what the gas might have been? CO2 perhaps?