While you are about it, add 8.8 grams of ascorbic acid and 6.6 ml of TEA to the liter of working solution without sulfite and check the activity.
Meanwhle, I cut the Metol to 0.01 moles /liter (3.44 grams), used 8.8 grams/l of ascorbic acid and 16.6 grams of sodium metaborate, and the activity is almost what it was with 0.05 moles of Metol.
I'm ashamed to say it, but 8.5 grams of Metol are 0.025 moles, although the resulting solution contains 0.05 moles of 4(methyl-amino)phenol after the sulfuric acid has been separated. The 3.44 grams actually make 0.02 moles of 4(methyl-amino)phenol. By some bit of luck, or maybe my brain was working then, I got the amount of hydroxide right so the solution pH is as close to 9 as my pH strips will tell me.
I found that the developer using phenidone gives about 1 f-stop more film speed, although I used the box speed with the Metol version and got good shadow detail. I guess the phenidone version would be good for unavailable light.
This is copied from the post on edge effects. Mix 1/2 teaspoon of Phenidone with a little isopropyl rubbing alcohol to make it easier to dissolve in water. Mix a couple of ounces of water, 2 teaspoons of ascorbic acid powder and 1 teaspoon of sodium bicarbonate and stir til the effervescence subsides. Warm it slightly to get more CO2 out. Add this mixture, the Phenidone, two teaspoons of borax and enough cold water to make 1 liter. Use it full strength or diluted as you would use D-76. At full strength it can be reused for at least 8 36 exp. or 8x10 films. All the teaspoon measures are levelled standard cooking measuring spoons.
Now let's play with p-aminophenol.
Paraminophenol is not very soluble in water. The potassium aminophenolate is quite soluble and a very active developer. Before we knew it as the proprietary Rodinal, Hurter and Driffield referred to a developing agent named rodinal, which I think might have been potassium aminophenolate. We can make a 0.05 molar solution of this rodinal from 0.05 moles of potassium hydroxide and 0.05 moles of p-aminophenol base, add to it 0.05 moles of ascorbic acid and another 0.05 moles of sodium or potassium hydroxide and some borax and end up with a kinder and gentler Rodinal expedient. Maybe.
This recipe is:
5.45 grams of p-aminophenol base
8.8 grams ascorbic acid
28 grams of sodium metaborate
Water to 1 liter.
( the 28 grams of metaborate includes the equivalent of 4 grams of sodium hydroxide and a bunch of borax.
I doubt that you will want to use this stuff full strength.
You can make a 2-part concentrated developer as follows.
Dissolve 22 grams p-aminophenol base and 35.2 grams ascorbic or erythorbic acid in about 400 ml propylene glycol. Add glycol to bring volume to 500 ml. This is solution A.
Dissolve 110 grams of sodium metaborate in water to make 500 ml. This is solution B. If you do not have metaborate, use 16 grams of sodium hydroxide or 22 grams of potassium hydroxide plus 76 grams of borax
Mix equal parts of A and B in water. A typical dilution would be 1:1:25. A typical development time for FP4+ would be 8 minutes at 70 F.
__________________
Gadget Gainer
Sponsored Ad. (Subscribers to APUG
have the option to remove this ad.)
If the ascorbic acid were regenerated, then this would be an electron transport developer. Unfortunately, if the other agent is consumed, it is not an ET developer. It is superadditive though.
If the ascorbic acid were regenerated, then this would be an electron transport developer. Unfortunately, if the other agent is consumed, it is not an ET developer. It is superadditive though.
PE
Say what? I am confused. That's a normal state of mind for me, but I need education. I think the ascorbic acid is consumed and the other agent is not, at least until the ascorbic acid is no longer able to function as a a reducer of the other agent. That seemed to be the conclusion reached by the experiment reported in Mees & James. What sort of concoction would keep both agents from being consumed? Don't give away any secrets if that is what this is about.
It appears that you have said that if either agent is consumed, it is not an ET developer. I don't recall seeking an ET developer. I've gotta go eat. I'll mull it over and try to figure out what you said.
Patrick; Any biochemistry text will draw chemical reactions with circular arrows for each reactant. Things keep cycling each other. With an ET developer, it can either recycle both ingredients or have one 'pump' the other in activity. Both types can be ET, but the former, with total cycling is distinctive enough to be clearly an ET developer. The latter requires many tests to show if it is an ET developer. It may or may not be. It may just be ordinary superadditivity.
The clue in this in the latter case is if either agent is virtually inactive alone even at high concentrations. Placing a large amount of the most inactive into the developer, and a tiny amount of the other (which is recycled) will give a very active, long lived developer with high capacity. The one at high concentration and with low activity is being used up to regenerate the small amount of the other agent.
Patrick; Any biochemistry text will draw chemical reactions with circular arrows for each reactant. Things keep cycling each other. With an ET developer, it can either recycle both ingredients or have one 'pump' the other in activity. Both types can be ET, but the former, with total cycling is distinctive enough to be clearly an ET developer. The latter requires many tests to show if it is an ET developer. It may or may not be. It may just be ordinary superadditivity.
The clue in this in the latter case is if either agent is virtually inactive alone even at high concentrations. Placing a large amount of the most inactive into the developer, and a tiny amount of the other (which is recycled) will give a very active, long lived developer with high capacity. The one at high concentration and with low activity is being used up to regenerate the small amount of the other agent.
PE
Now I feel better. That is what I thought I was doing, although I agree that 0.05 moles of p-aminophenol is probably not a relatively small amount for a working solution considering that Rodinal has less than 1/5 that much in a 1+50 working solution. The pH of Rodinal is quite high, while my experimental stuff is between 9 and 10, probably that of a borax solution.
The working solution I use with the concentrate diluted 1+1+25 has only about 0.8 grams/liter.
Linear Mode
