Quote Originally Posted by sanking

I also have some very old phenidone that appears to be fully active.

On the other hand, I checked a small bottle of glycin from the same period and it was totally worthless. The white powder was very dark brown and had virtually no activity.

Does glycin dissolve easily in propylene glycol? If so this his might be a good way to store it.

Sandy, my tests show that glycin is only slightly soluble in propylene glycol - even at elevated temperatures.

However, propylene glycol still might be a good way to keep premeasured amounts of glycin stable by preventing or retarding oxidation(even though only a small percentage dissolves in the PG). It is worth trying (before my current supply of glycin goes bad).

Glycin does dissolve in triethanolamine (TEA) at high temperatures. However, a TEA/glycin stock solution that I recently mixed (about 2 weeks ago) has changed color and separated into two distinct layers. I need to test the stuff and see if it is still active.