[scheimfluger_77]

The old canned air products you recall were halogens. Hello ozone hole over antarctica, get bigger now. That's why you don't find them any more.

Ah! That would explain it. Having just reviewed a periodic table Nitrogen is probably not a good choice for a "blanket," being as Nitrogen is lighter than Oxygen. It seems Argon is a common gas used where a non-oxygen environment is required. Couple that with a brown glass bottle and a lid that actually seals the opening and your oxidation problem should be minimal.

Steve