P-aminophenol base

[John Wiegerink]

Quick question! Where do you buy your p-aminophenol base from?

 

[koraks]

Is yours an application where it's feasible to simply use paracetamol and sodium hydroxide?

 

[john_s]

I was under the impression that it was a common chemical. I bought mine from Merck (I'm in Melbourne Australia). Maybe try general chemical suppliers.
I found that mine deteriorated over several years and had to be discarded. Most other developing agents seem to last for ages.

 

[John Wiegerink]

Is yours an application where it's feasible to simply use paracetamol and sodium hydroxide?

I was looking at one of Pat Gainer's suggested developer and got curious. It was this one:

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.


He also posted this in the same thread.

p-aminophenol(base).....1.1 grams
ascorbic acid................8.8 grams
2.4 grams sodium hydroxide + 10 grams borax
or
sodium metaborate........16.7 grams

Water to 1 liter.

 

[Rudeofus]

The p-Aminophenol you will easily get is likely the salt of Hydrochloric Acid or maybe the sulfate, but AFAIK only rarely the free base. Fortunately it doesn't matter much, the few extra chloride ions will not matter much except for one thing: acidity. p-Aminophenol is a strong base, comparable to metaborate or carbonate.

Since your soup already uses Sodium Metaborate, I recommend the following:

1. Get the much easier available p-Aminophenol Hydrochloride
2. Substitute the free base mol for mol with the hydrochloride
3. Take the number of mols you just calculated and add the same number of mols of Sodium Metaborate to the formula

This should get you at least into the ballpark.

 

[John Wiegerink]

The p-Aminophenol you will easily get is likely the salt of Hydrochloric Acid or maybe the sulfate, but AFAIK only rarely the free base. Fortunately it doesn't matter much, the few extra chloride ions will not matter much except for one thing: acidity. p-Aminophenol is a strong base, comparable to metaborate or carbonate.

Since your soup already uses Sodium Metaborate, I recommend the following:

1. Get the much easier available p-Aminophenol Hydrochloride
2. Substitute the free base mol for mol with the hydrochloride
3. Take the number of mols you just calculated and add the same number of mols of Sodium Metaborate to the formula

This should get you at least into the ballpark.

Thanks, that's probably the way I will go. Winter doldrums are setting in in Michigan, and playing with developers is something to do instead of plopping down in front of the boob tube.