Ascorbate paper developer

Tom Hoskinson · Dec 11, 2004

Phenidone and sulfite in combination with water make up Marilyn Levy's POTA developer.

The sulfite provides the pH needed to make the Phenidone go.

REALLY, REALLY S L O W!

gainer · Dec 11, 2004

psvensson said:
The odd thing is that the MSDS for Agfa Neutol Plus, a PA print developer, lists sulfite as one of the components. Maybe it preserves some other component, but I wouldn't know what.

It may have some quality that my developer doesn't, and I have nothing against sulfite per se. I try to make things simple by starting with the minimum and working up rather than the other way because if you assume that something is necessary you may never find out it wasn't.

I think most of us, including myself for about 60 years, consider sulfite to be a necessary ingredient of developers. It preserves developing agents, it dissolves grain edges, and it is necessary to superadditivity is it not?

I find in my old age that ascorbic acid and some of its relatives are superadditive with the usual agents without sulfite, and that it is a better preservative than sulfite, which means it preserves the sulfite, not the other way round. All that's left is chewing away grains, and I don't need that. Ascorbates without sulfite are surface developers which seem to have advantages in speed/grain ratio.

Ryuji Suzuki has found that salycilic acid preserves ascorbates, but not much else will. My tack is to make concentrated tock solutions in non ionic solvents. The working solutions will not last forever, but will last long enough to do the job.

I'm not trying to be contentious here. I say use the KISS principle and add what it takes to make it work. It's like being a cook. He can add what it takes to make a good dish. Taking away is another matter.

dancqu · Dec 12, 2004

Slipped my mind. Why so so slow? The very large amount of phenidone
is not likely the reason. Two possible reasons may be a marginal
ph for activation AND the lack of regeneration.

An interesting formula can be found at www.frugalphotographer.com .
Although it has no metol it does remind me of Perfection XR-1.
Note the amount of hydroquinone in the formula. A. acid, for
those who need that vitamin C, perhaps will subsitute. Dan

gainer · Dec 12, 2004

Although vitamin C often seems to act as a substitute for hydroquinone, it differs in important aspects. Hydroquinone will not superadd with metol or phenidone unless there is at least 1.2 g sulfite present for each gram of hydroquinone. Ascorbic acid needs no sulfite. You will not learn the full benefits of ascorbic acid until you try it without sulfite. So, in the formula under discussion you should try substituting sodium ascorbate for the hydroquinone-sulfite combination. Ascorbic acid with a little extra carbonate to convert it to the ascorbate will do.

Without the sulfite, ascorbate is a surface developer, working on the surface of crystals.

psvensson · Dec 12, 2004

Larry, I tried making a two-bath ascorbic acid/carbonate paper developer today, but couldn't get it to work. I tried both acidic, neutral and slightly alkaline first baths, with up to 4 tbsps ascorbic acid in 500 ml of water. Nothing I tried gave me a good D-max - in fact, skipping the first bath gave equally good results.

I've tried making a two-bath ascorbic film developer before, with equal lack of success. I think it has to do with the reaction product of ascorbate being acidic. When the film or paper goes over into the second bath, the ascorbate in the emulsion neutralizes the developer as it oxidizes, shutting down development too soon. This seems like something hydroquinone would do better.

dancqu · Dec 12, 2004

gainer said:
Ryuji Suzuki has found that salycilic acid
preserves ascorbates, but not much else will.

IIRC, Mr. Suzuki's inclusion of salycilic acid in a formula is
for the purpose of complexing with impurities; ie iron,
copper, etc.

I've tryed to no avail so far but have attempted to refind via
Google an article dealing with the preservation of pharmaceuticals.
The break even point for the duo A. acid/sulfite is ph 5. Below
that ph sulfite will absorb oxygen more readily.

A. acid plus bisulfite will yield a solution ph of 3.5 +/-. A. acid
itself has a ph a few tenths lower and in a solution of distilled
water, properly contained may last quite a while. I did mix the
two and bottled the solution for a latter keeping quality test.
I've just finished a redue of my lab and it appears that the
solution was tossed. Dan

psvensson · Dec 13, 2004

dancqu said:
The break even point for the duo A. acid/sulfite is ph 5. Below
that ph sulfite will absorb oxygen more readily.

A. acid plus bisulfite will yield a solution ph of 3.5 +/-. A. acid
itself has a ph a few tenths lower and in a solution of distilled
water, properly contained may last quite a while.

So you're saying that in an alkaline solution, ascorbate preserves sulfite, but below pH 5, sulfite preserves ascorbate? That's really interesting.

gainer · Dec 13, 2004

psvensson said:
Larry, I tried making a two-bath ascorbic acid/carbonate paper developer today, but couldn't get it to work. I tried both acidic, neutral and slightly alkaline first baths, with up to 4 tbsps ascorbic acid in 500 ml of water. Nothing I tried gave me a good D-max - in fact, skipping the first bath gave equally good results.

I've tried making a two-bath ascorbic film developer before, with equal lack of success. I think it has to do with the reaction product of ascorbate being acidic. When the film or paper goes over into the second bath, the ascorbate in the emulsion neutralizes the developer as it oxidizes, shutting down development too soon. This seems like something hydroquinone would do better.

You don't mention a synergistic agent to go with the ascorbic acid. Ascorbic acid alone is not very selective. I have experimented with it as a line copy developer and it needed very high pH and lots of bromide to work cleanly, and then had no advantage over hydroquinone.

gainer · Dec 13, 2004

psvensson said:
So you're saying that in an alkaline solution, ascorbate preserves sulfite, but below pH 5, sulfite preserves ascorbate? That's really interesting.

My feeling is that if you are going to use sulfite as a preservative only, forget it in ascorbate developers. I can preserve the necessary developing agents in an organic solvent. Mixed with water they last long enough to do the job. Aerial oxidation needs air to work, and there's very little of that in a closed developing tank. Ryuji's premise is that ordinary chelating agents do not hold ferrous iron, which attacks ascorbates. Salycilic acid is a chelating agent for ferrous iron. He is concerned with stock solutions and working solutions in water. Ferrous iron is common in water, even some so called distilled water.

Oxidation is a necessary part of tanning and staining development. I don't know why I mention that here. The products of oxidation are essential to certain methods of development, and maybe to all if you consider that the developing agent is oxidized in reducing film or paper.

dancqu · Dec 13, 2004

psvensson said:
So you're saying that in an alkaline solution,
ascorbate preserves sulfite, but below pH 5, sulfite preserves
ascorbate? That's really interesting.

I'm not saying that I said that. That is from a article dealing with
the preservation of pharmaceuticals. I've no reason to doubt. I'll
"surf" a bit today and may bring that article up again.

Covering the subject of preservation in solution they mention two
guidlines. The first is to keep acid. The second is to include an
oxygen scavanger. Sulfite will scavange at any ph but to do
so for A. acid, and do it well, I'd think the ph should be the
lower the better.

Considering the amount of A. acid used, why not just premeasure
or, heaven forbid, spoon it in at process time? Dan

fhovie · Dec 13, 2004

How will the DS-14 - PC TEA developer listed in the recipe section compare with
Amidol on AZO paper???

Tom Hoskinson · Dec 13, 2004

fhovie said:
How will the DS-14 - PC TEA developer listed in the recipe section compare with
Amidol on AZO paper???

My first tests were encouraging. However, in my A-B comparisons with Azo, the MS Amidol/Azo combination won.

I am still hoping that with split development (DS-14 and DS-15) I will achieve a result that is competitive with MS Amidol.

fhovie · Dec 14, 2004

wow! I mixed it up like the posted instructions DS-14 - great blacks On AZo but maybe too much contrast. Is this developer really temp sensitive? It was probably at almost 80f when I used it. I made about 8 8x10 sheets and bottled it in an air tight purge bottle - I wonder if it will work in a few days. I added the Benzo and it made no difference. I made a 10% Benzo in alcholol and added a few drops to the I liter of working solution. Is there anything I can add to turn down the contrast a little?

dancqu · Dec 14, 2004

I know it's important for everyone to have correct information.
If not correct, corrected. So this correction:

The ph of a weak A. acid solution is 2.3 and that of a weak
bisulfite solution, 3.2. That to the best of my old Hanna pHep II.
I will be checking again those ph with my brand new Milwaukee
SM102 dual probe ph/temperature meter; $99.
See at www.automatedaquariums.com

While on the subject of ph, visit www.microessentiallab.com .
Thay carry a vast selection of indicator papers, ph and others.
They have a fix silver paper and one just for Mr. P. Gainer.
An antifreeze paper, what else? How about that! Dan

Tom Hoskinson · Dec 15, 2004

fhovie said:
wow! I mixed it up like the posted instructions DS-14 - great blacks On AZo but maybe too much contrast. Is this developer really temp sensitive? It was probably at almost 80f when I used it. I made about 8 8x10 sheets and bottled it in an air tight purge bottle - I wonder if it will work in a few days. I added the Benzo and it made no difference. I made a 10% Benzo in alcholol and added a few drops to the I liter of working solution. Is there anything I can add to turn down the contrast a little?

Yes, it is temp sensitive. For example, 3 minutes at 68F is approximately equal to 1.8 minutes at 80F.

Like JDEF says, to reduce the contrast, the first thing I would try is adding water (I would start by diluting the working solution 1:1). Another thing I would try is reducing or eliminating the sodium carbonate in the working developer (thus relying on the TEA as the only alkali) .

Maine-iac · Dec 16, 2004

gainer said:
Although vitamin C often seems to act as a substitute for hydroquinone, it differs in important aspects. Hydroquinone will not superadd with metol or phenidone unless there is at least 1.2 g sulfite present for each gram of hydroquinone. Ascorbic acid needs no sulfite.

I mixed some Phenidone-Vitamin C-Benzotriazole paper developer recently (no sulfite). Worked OK, but didn't give me the "zing" in the print tones that my more usual Metol paper formula did. So I added a bit of Hydroquinone, and it really zinged things up a lot. So I'm wondering about your statement that HQ will not superadd without sulfite present. It sure did something.

Larry

Maine-iac · Dec 16, 2004

psvensson said:
Larry, I tried making a two-bath ascorbic acid/carbonate paper developer today, but couldn't get it to work. I tried both acidic, neutral and slightly alkaline first baths, with up to 4 tbsps ascorbic acid in 500 ml of water. Nothing I tried gave me a good D-max - in fact, skipping the first bath gave equally good results.

I've tried making a two-bath ascorbic film developer before, with equal lack of success. I think it has to do with the reaction product of ascorbate being acidic. When the film or paper goes over into the second bath, the ascorbate in the emulsion neutralizes the developer as it oxidizes, shutting down development too soon. This seems like something hydroquinone would do better.

I think you're right about the need for Hydroquinone. My normal paper developer is a Metol-based formula, similar to Dektol. In experimenting with Phenidone-Vitamin C paper developer, I found that I wasn't getting much activity and was getting weak blacks, etc. So I added some Hydroquinone (I'd have to go to my darkroom to look for the exact amount, but I think it was around 1/2 tsp.) to the Bath A mix. My next prints virtually "popped" out of the tray when they hit the Bath B. I also added my usual 10 ml of Edwal's Liquid Orthazite (Benzotriazole) to Bath A, but that's just for anti-fog and I don't really know if it's necessary. But I'm pretty sure it was the HQ that did the trick. I don't pretend to understand the chemistry of it completely, but it did juice things up.

If you're interested in the Metol formula, I'll send it along when I have the chance to copy it from where it's tacked to my darkroom bulletin board.

By the way, with the divided technique, you can use two Bath A's if you wish to vary contrast. If you want a softer print, use a soft Bath A (similar to Selectol-- leave out the HQ or cut it way down--in the Metol-based formula). If you want a harder or more normal contrast, use a Bath A that's a more contrasty formula. If I'm printing a variety of negs shot from a variety of time periods and they're a mixed lot in terms of contrast, I'll often have both Bath A's mixed up, so that I can use whichever is better suited to the negative I'm printing.

Larry

gainer · Dec 16, 2004

Strange. I seldom use hydroquinone in combination with ascorbic acid, although I have experimented with it. If I don't get enough black with PC-carbonate, I add more carbonate. Another alkali I use when I don't have rain or distilled water is a tablespoon of borax + a teaspoon of lye to the liter. If you are a stickler for weighing things out, weigh a tablespoon of borax and a teaspoon of lye and use those weights.

I have found that sulfite does no noticeable good unless you have hydroquinone. Then you get lots of activity.

gainer · Dec 16, 2004

Forgot to mention I use a tablespoon of ascorbic or isoascorbic acid and 1/2 teaspoon of metol to the liter.

Maine-iac · Dec 17, 2004

gainer said:
Forgot to mention I use a tablespoon of ascorbic or isoascorbic acid and 1/2 teaspoon of metol to the liter.

Not metol WITH Phenidone, surely? I, too have used metol most frequently for my paper developer, sometimes with Vitamin C and sometimes with sulfite and/or HQ.

I think the reason I was getting weak blacks with just PC-carbonate in a paper formula, is that I always do divided development for paper. So it's possible that the PC in Bath A is not getting sufficiently activated by the carbonate in Bath B, which is perhaps why I've stuck with metol in Bath A most of the time. Or perhaps I just didn't have a strong enough concentration of PC. But I could hardly believe how much "pop" I got with this recent formula simply by adding some HQ to the PC in Bath A. Bath B remained my usual 1/3 cup per 2 liters of water. I also put 10 ml Benzotriazole (Liquid Orthazite) in the PC or PCQ bath.

grainyvision · Jan 26, 2020

Super dead thread bump, but this was the most relevant thing I found in my searching on this topic..

Anyway, I believe I’ve found a preservative of ascorbic acid. I can’t honestly determine if it just prevents it from decaying, or works to reduce ascorbic acid’s oxidation products and/or radicals. The chemical is potassium oxalate. I tried an experiment where I mixed probably 5g of ascorbic acid, 3g of lye, and some carbonate (this was heavily experimental) and 4g of oxalate. The results weren’t great. I was searching for a lith printing developer without hydroquinone and couldn’t get a proper Black with modern papers. With some old paper I got heavy fogging and still poor blacks. Regardless, I left it out overnight. I added enough lye etc that the ph was sitting at around 13.5 when I left it. I came back the next day about 24 hours later to a slightly purple solution. It still developed paper but was very slow so I spiked it with like 1.5g of lye. It worked pretty much the same as the previous day but rather than making warm tones have extremely cool almost purple tones but still no proper black. I added some hydroquinone to the solution, probably 1g... and note the ph is around 12.5 now and no sulfite is present. The solution went a a very pale yellow and no other sign of hydroquinone decay (no red film). I tried developing some a few types of paper but neither modern nor old paper could get to a proper black, the tones almost became a more cool neutral. This didn’t seem to help contrast nor blacks though. I then added even more HQ, but at this point it went a deeper yellow and the typical red film of HQ decay occurred.

regardless, a rather interesting experiment, but oxalate seems to preserve ascorbic acid well but also likely affects the activity of it

Ascorbate paper developer

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