Yikes, PPPD turns red?

Bruce Osgood

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I brewed a half gallon stock and air sealed it with butane. Last night I diluted 250 ml 1 + 1 to make a working tray and it looked slightly yellow, like a fresh indicator stop bath.

Made my print and developed it. Decided to make some adjustments in the print and noticed the developer was a deep red/amber color.

Made the second print and had trouble finding the paper under this dark, dark solution. The print was fine and the stuff really works but does it turn almost black in use?

Anybody got an idea?
 

Donald Miller

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Bruce, I always recommend mixing the developer immediately prior to use. If you mix it prior to use, (as in a stock solution) then the carbonate should be kept separate from the other ingredients...in other words mix two stock solutions. When the carbonate is mixed with the other ingredients, the solution begins to oxidize immediately. I am surprised that you had any activity from it as it was.

Yes, it will darken during the printing cycle.
 
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Bruce Osgood

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AHHHH, thank you Donald.... this may explain another mystery I (probably mistakenly) attributed to the P-Cat negative. I had to open the enlarger lens at least two stops to get enough light to make the print.

So, I will remake a single liter without sodium carbonate and reserve it till time of use. Then I will add the carbonate and dilute 1 + 1.
 

lee

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for what it is worth, my pppd is an orange color. works just fine

lee\c
 

Alex Hawley

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I'm pretty sure the orange color comes from the pyrogallol oxidation. Saw the same thing in ABC pyro developer. When I've mixed PPPD without the pyrogallol, there's no orange color.
 

gainer

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Just about any developer based on aniline or phenol will turn dark on aerial oxidation. The intensity of the color is no sure measure of its activity, but it surely can be a hindrance to print developing when you can't see the print.

To demonstrate the lack of correlation between color and activity, add 1/8 teaspoon (5/8 ml) of Rodinal concentrate to a few ml of water and let it oxidize in air. In a day or so, you can bring the water level up to 250 ml and still not be able to see through it. In other words, 4/5 ml of aerially oxidized Rodinal concentrate can make 500 ml of Rodinal concentrate look very bad while the actual loss of activity is 0.25 % or less. I say less because an oxidization product of Rodinal is a hydroxide, either sodium or potassium, which tends to increase the pH. If there is excess p-aminophenol in the stock, some of it will be converted to the sodium or potassium aminophenolate. The moral is color is no indicator of ability.
 

lee

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Alex,
possibly you are correct but I tend to think that it is my phenidone as it is not pure white and more of a yellow tint to it. When I put it in the alcohol to dissolve it that is when I see the orange appear.

lee\c
 

gainer

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lee said:
Alex,
possibly you are correct but I tend to think that it is my phenidone as it is not pure white and more of a yellow tint to it. When I put it in the alcohol to dissolve it that is when I see the orange appear.

lee\c
Click to expand...

The first phenidone I bought many years ago came from Ilford. It was a yellowish powder. It was still working several years later. However, it is true that the color of oxidized phenidone is red. You might try using glycerine or propylene glycol instead of alcohol as a solvent for the phenidone to see if it still turns orange when you dissolve it. You should be able to get glycerine at the drug store. It is pretty viscous at room temperature, but not too bad if you warm it in a water bath before measuring the phenidone solution into your developer.
 

lee

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hi Patrick,
WRT to heating the phenidone in glycerin, would it be ok to pop it in the microwave and heat it that way? I dont have any other way at this time to heat the glycerin or alcohol.

lee\c
 

Alex Hawley

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lee said:
Alex,
possibly you are correct but I tend to think that it is my phenidone as it is not pure white and more of a yellow tint to it. When I put it in the alcohol to dissolve it that is when I see the orange appear.

lee\c
Click to expand...

Same here with the phenidone Lee, but I'm talking about the whole solution turning orange progressively as it sits in the tray. It becomes noticeable by twenty or thirty minutes after mixing everything together and continues to become more so as time progresses.
 

lee

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that is correct alex the whole of the PPPD is orange after a bit

lee\c
 

gainer

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lee said:
hi Patrick,
WRT to heating the phenidone in glycerin, would it be ok to pop it in the microwave and heat it that way? I dont have any other way at this time to heat the glycerin or alcohol.

lee\c
Click to expand...
The microwave for a few seconds will work, but you probably don't need it. The heating is solely for reducing viscosity and a water bath of hot tap water should do the job. It doesn't have to be any hotter than you would use to wash your hands, or than coffee or tea that you could drink. If you don't have a water heater, the safest way to use the microwave is to heat the water bath.
If you can put up with the slow pouring, you can do without any heating above room temperature.
 
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