Quote Originally Posted by gainer View Post
You will be happy to find out that the experiment failed when I tried to bring the concentrations of p-aminophenol and ascorbic acid up to the level we're looking for in a concentrated stock. The only real difference is the substitution of about 29 grams of potassium ascorbate for 192 grams of potassium sulphite in 500 ml. What am I missing?
Ascorbate may not regenerate p-aminophenol.
I made some PaRodinal,added sulfite to make it solvent,then reduced the pH to about 8.5 by adding either ascorbic acid or boric acid.The ascorbic acid did not seem to give any extra activity compared to boric acid.I found no benefit in modifying PaRodinal in this way,it merely produces a developer that takes twice as long as D-76 to produce a rather similar result.IDK if the p-aminophenol version is more resistant to oxidation than D-76.
However,this was only one experiment but IIRC many have found adding sodium ascorbate to Rodinal to have some benefit,I don't know the cause of that.