As well as that test for oxidation I hope to do a test to find if phenidone/dimezone-s will hydrolze by reaction with the water of crystallization in one of these developers.
To speed up the reaction it is intended to place full sealed bottles of concentrate on top of a hot water tank ~40C.
Hydrolysis of phenidone produces phenylhydrazinopropionic acid: C6H5.N.CH2.CH2.CO.NH +H2O -> C6H5.N(NH2).CH2.CH2.CO.OH
Not a lot of people know that.