Ortho-Lith developer

[OptiKen]

I'm going to make up some developer to try on my Arista Ortho II film and want to have an idea of how long I can store it.

Stock is:
5ml Rodinal
20ml .2% Benzotriazole
4ml .1% Potassium Iodide
1000 ml distilled water

How long will the above stock solution keep?
More importantly, how long will the .2% Benzotriazole and the .1% Potassium Iodide keep?

I plan to mix the stock solution as needed so storage isn't really going to be an issue there.
I will be making up a liter each of the other solutions so I would like to know how long the .2% Benzotriazol and .1% Potassium Iodide will keep

 

[Gerald C Koch]

The benzotriazole solution is quite stable. The potassium iodide solution is not. The iodide ion will disproportionate in water solution. That is the iodide ion will both oxidize and reduce itself. Some will be converted to elemental iodine while some will be converted to iodate ion.

 

[OptiKen]

Thank you.