Glycin and phenidone are notorious for their short shelf life. I am wondering if anyone tried to prolong the shelf life by sealing then in vacuum, using jars with Vacu-Vin type stopper or FoodSaver. FoodSaver bags are said to be a triplet, one nylon layer (good oxygen barrier but poor moisture barrier) and two polyethylene layers (good moisture barrier but poor gas barrier) so it might be effective.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), April 11, 2002

Answers

I talked with Photographers Formulary about flooding my Glycin with argon or nitrogen to retard oxidation. They thought it was an excellent idea, but when I realized how lightweight the powder is, and how easily it would end up floating around the darkroom, I abandoned the idea. Much safer to keep buying it in smaller quantities. Not sure if vacuum would be better.

-- Conrad Hoffman (choffman@rpa.net), April 11, 2002.

There are folks who roast coffee at home, and grind every few day's dose and vacuum seal to bring to their office. I do this too, except I haven't tried vacuum sealing part yet. Coffee itself doesn't justify buying vacuum sealer because I have a spare grinder anyway.

You can do double packing. One layer of bag without vacuum, but you make a small hole. You put this bag in vacuum-proof bag, and vacuum seal it. Powder won't come out to interfere the pump or sealer.

You coluld also put glycin in 35mm film canister, and put them in a vacuum jar. If you use Konica canister, there is a small airway around the lid. Otherwise, you can make a small hole.

I'm not too fond of nitrogen sealing even for wines... if the bottle is good, I'll drink it in the same night anyway :-)

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), April 11, 2002.