The last time I made a Phenidone-based developer (ID-67), I mixed the ingredients in the following order:
Phenidone 0.5 g
Sodium Sulphite (anh) 50 g
Hydroquinone 12 g
Sodium Carbonate (anh) 60 g
Potassium Bromide 2 g
Benzotriazole 1% soln 20 ml
Water to 1 litre
What I noticed (I don;t recall seeing it before when I've made this developer) was that immediately on adding the Phenidone to the water, the water turned pink, even though I had added a spoonful of sulfite to the water and dissolved that first (as often suggested for metol developers, as an oxygen scavenger.)
My rudimentary knowledge of photo-chemistry suggests that this means the Phenidone was immediately undergoing oxidisation, and thus I wondered to what extent this might be problematic.
The pink remained even after adding the remainder of the sulfite, but disappeared immediately upon adding the smallest amount of hydroquinone (again, my rudimentary understanding suggests this is the result of the hydroquinone regenerating the oxidised Phenidone in solution).
Any comments from one of our chymists?
Need I be concerned?
Will the (presumed) oxidisation of the Phenidone likely make a significant difference to the developer's properties?
Would it be better to add the Phenidone after the HQ?
(Comments along the lines of "Don't bother, just buy a gallon of Dektol from B&H" won't be considered useful contributions by the way
)
Phenidone 0.5 g
Sodium Sulphite (anh) 50 g
Hydroquinone 12 g
Sodium Carbonate (anh) 60 g
Potassium Bromide 2 g
Benzotriazole 1% soln 20 ml
Water to 1 litre
What I noticed (I don;t recall seeing it before when I've made this developer) was that immediately on adding the Phenidone to the water, the water turned pink, even though I had added a spoonful of sulfite to the water and dissolved that first (as often suggested for metol developers, as an oxygen scavenger.)
My rudimentary knowledge of photo-chemistry suggests that this means the Phenidone was immediately undergoing oxidisation, and thus I wondered to what extent this might be problematic.
The pink remained even after adding the remainder of the sulfite, but disappeared immediately upon adding the smallest amount of hydroquinone (again, my rudimentary understanding suggests this is the result of the hydroquinone regenerating the oxidised Phenidone in solution).
Any comments from one of our chymists?
Need I be concerned?
Will the (presumed) oxidisation of the Phenidone likely make a significant difference to the developer's properties?
Would it be better to add the Phenidone after the HQ?
(Comments along the lines of "Don't bother, just buy a gallon of Dektol from B&H" won't be considered useful contributions by the way
