Amidol differences???

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In using Amidol I find that fresh chemistry gives a really nice print. I make amidol print developer & have used fresh, old, really old and the RED version... a fresh mix but red in color in solution.

All work with the fresh stuff being better than any of the others in my darkroom.

Since others also have the red amidol it appears that all Amidol is not equal.

If we are ordering some, what do we look for? Amidol is apparently also used in the food & hair dye industry. Are we OK finding a hair dye chemistry supplier & purchasing Amidol from them or is their version different from what we need for photo processing? The red stuff develops fine but turns fix pink & leaves a pink/warm coloring to the paper when we use it, something none of the old stuff I have & use does. Do I go anywhere and just ask for Amidol & come up with yet another variation in color? Or, do I ask for something specific & how can I be sure I get what I want?

-- Dan Smith (shooter@brigham.net), March 03, 2002

Answers

Dan I would say call photographers formulary and ask what kind of grade is their Amidol. In chemistry we have different types of grades depending on the application. For example there is technical grade, indsutrial grade etc. Technical being the more pure, I have also seen some chemicals labeled photography grade, but this was many years ago I am unsure if this is still in use. Being the the food and dye industries are using amidol as a colorant, I would stay away from this if you did not like the red kind. Hope this helped.

-- jorge gasteazoro (rossorabbit@hotmail.com), March 03, 2002.

I have never heard of red amidol. Where do you get it? I recently purchased some amidol from Photographer's Formulary, and its quality was not what I would prefer, though it is useable. It reminded me why I had switched to using amidol from Bryant Labs in Berkeley (1101 Fifth St., 510-526-3141 or 800-367-3141). The amidol from PF is dark grey and a bit chunky, whereas the amidol I purchased from Bryant was a nearly white crystalline powder, which kept well for more than two years. The Bryant Labs stuff is more costly--I don't know if it is still available or not, but it is of a superior quality.

Off-subject comments: Bryant has a good price on gold chloride, but most of their other stuff is expensive. I recently purchased some potassium dichromate from Photographer's Formulary and had the opportunity to compare it to that from Bryant. The stuff from Bryant was milled to homogeneous-sized grains that poured smoothly from the container without scattering, whereas the stuff from Photographer's Formulary contained all different sizes of crystals which tended to bounce and scatter when I poured it from the container. Every time I use this new stuff from PF it makes a big mess, which I must carefully clean up because of the extreme toxicity, corrosiveness, and oxidation potential of potassium dichromate. I much prefer the more uniform product from Bryant Labs. This isn't to denigrate Photographer's Formulary in any way--they offer a great service to darkroom enthusiasts, but when dealing with chemicals like potassium dichromate I think I will go with the more expensive brand.

-- Ed Buffaloe (edb@unblinkingeye.com), March 04, 2002.


Dan,

Amidol (2,4-Diaminophenol dihydrochloride) is colorless when ultra- pure. It quickly oxidizes and takes on an increasingly dark color. A very small amount of oxidation can color the material intensely, so it's hard to say much about purity just from color. I buy amidol from Artcraft Chemicals and get a light gray fluffy powder. Check out Artcraft’s price (www.artcraftchemicals.com), it's the best I’ve seen.

I've never seen red colored amidol crystals.

-- Linas Kudzma (lkudzma@compuserve.com), March 04, 2002.


I can't imagine that Amidol is used in the food industry due to high toxicity. Not sure about hair, but I doubt it. You have to be careful because chemical trade names aren't always the same from industry to industry. You might be getting a close cousin, but not what you want. Follow the others advice on suppliers. I've been happy with Photographers Formulary (I don't use Amidol) but have to agree that the mechanical properties of some of their chemicals are a bit inconsistant. Another way to make a mess is to use a plastic spoon to measure out their sodium hydroxide. The static charge sucks the little round balls out of the jar and shoots them all over the workbench! Flakes would be safer.

-- Conrad Hoffman (choffman@rpa.net), March 04, 2002.

Like Conrad says, I doubt Amidol is used in food processing because it is toxic but who the hell knows? I always thought the reason Amidol was so expensive was because photography was about the only use for it (as compared to something like sulfite which is used in mountainous quantities in food processing). I kind of like slightly used Amidol in solution. After I've put a few prints through it, it starts giving me a very pleasant warm tone that I like - I know that the oxidation product of Amidol is supposed to be an incredibly good restrainer, so maybe there is something going on. I've ordered Amidol from Artcraft and its always been decent - it arrives as a light grey green powder and stays that way for quite some time if you keep the air out. If left long enough, it forms some black crystals but these black crystals still seem to work fine (maybe its only the surface of the crytal that is oxidized and the insides are fine). I've noticed minor differences in tone but I can't rule out that this might have been some other process variation. In general, the stuff works fine. I'm curious about this red version - have never encountered it before. Incidentally, some Amidol formulae are actually quite cheap. I've also never had the famed problem of Amidol being shortlived. I've put upto 60 8x10 prints through a litre over a 48 hour period and the Amidol was still going strong. Cheers, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 04, 2002.


The 'red' amidol I refer to is a batch made in japan that is being sold worldwide these days. When you mix the developer it looks the color of oxblood shoe polish & tints the print a pink color and the fix a real pink/red. Disconcerting to say the least.

Doing a Google search on Amidol shows it coming up in boht hair dyes and food/sugar processing. Haven't checked the exact chemical formulation to know if this is the same product, a minor variation or something called the same while very different. I just started searching to find a source of Amidol that might be lower in cost than some current suppliers.

As for Amidol & some doubting it could be used in the food industry... why not? Being toxic has never stopped anything from being used there if a dollar was to be made.

-- Dan Smith (shooter@brigham.net), March 05, 2002.


Lets remember that toxicity is also dependent on dosage, so although it might be used in food or dies, the concentration used it is not considered toxic. OTH tobbaco does not cause cancer, right?

-- Jorge Gasteazoro (rossorabbit@hotmail.com), March 09, 2002.

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