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  1. #21

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    Quote Originally Posted by avandesande
    Even if you forget about possible toxicity it is an annoying solid to handle. It is fluffy and sticks to things because of static charge.
    I agree. Amidol is one of the chemials that I least enjoy working with in powder form. It would be a great advlantage IMO to be able to store it in liquid form that would not degrade.

    Sandy

  2. #22
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    Things have taken a little turn here, as usual. Sandy wanted to make a solution containing significant amounts of amidol and pyrogallol in TEA. Storing amidol base in glycol or TEA solution seemed a way to do it, but if the main purpose is to have a final soultion like , say, PMK with all necessary ingredients in a concentrated stock including the alkaline activator, and you are hell bent on using amidol in place of metol, then it seemed that getting rid of the hydrochloride would be a good thing to do. That was put there to make amidol base soluble in water, but also made it not so soluble in glycol or similar organic solvents. Now you only have to handle the dreaded powder once or several hundred rolls or sheets of 8x10 film. Gordon Hutchings says to use a pinch of the powder. I presume he is still among the living and ripening normally.

    The color of the pyrocat-amidol-TEA-bisulfite solution is very dark brown for all I can tell, but I can't see through more than half an inch of it. If I dilute it 1+1 with more TEA, I still can't see through it. It looks more like coal tar than a couple of coal tar derivatives. If I add 2 grams of sodium sulfite to a liter of 1+50 working solution, it turns to a very light amber color, not even dark enough to tempt anyone to drink it. Along with the color goes the coveted stain.

    With only the 10 grams of bisulfite per liter of stock solution, which now is pretty much like Pyrocat M with amidol instead of M and dissolved in TEA, the working solution is somewhat darker when first mixed and rapidly darkens. I developed a test strip of Arista II 100 by the semi-stand method for 21 minutes at 70 F, agitating at 0, 7 and 14 minutes. The negative is very thin by most standards, but has all the detail. So far I have only scanned it, but the scanner loves it. It could have stood 30 minutes, I'm sure, but 35 mm users prefer, or should, low contrast negatives with minimum correct exposure.

    I digress, as usual. Anyway, I think the original purpose has been met.

    As regards saving amidol for use in paper developer, the same advantage applies of only having to encounter the powder once in a number of liters of developer rather than each time you mix it. I'm not trying to sell it or sell anybody on using it, just pointing out some facts along with a few suppositions.
    Gadget Gainer

  3. #23

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    Quote Originally Posted by avandesande
    It is fluffy and sticks to things because of static charge.
    Interesting, the amidol that I used some years ago to develop nuclear emulsions was granular and easy to handle. Same for the pyrogallol. I have heard that there is a fluffy form of this too. BTW, by creating a large volume of solution you create the potential problem of spills and the difficulty of cleaning them up. Trading one problem for another. I would be inclined to look around for granular forms of these two chemicals.

    LD50 values show a considerable variation, being partly dependent on the animal used (mouse, rat, rabbit, ...). Aldrich Chemical lists that for amidol (rat) as 240 mg/kg; JACTDZ 13,330,1994. Interestingly that for hydroquinone is equal to that for Tylenol, 300 mg/kg. Tylenol being toxic to the kidneys and liver. Doses facit venenum. It is the dose that makes the poison. While we should respect chemicals we should not fear them. I have worked with americium and plutonium, two of the most toxic substances known. I say this not to brag but to make the point that I would have been out of a job had I feared them.

  4. #24

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    Quote Originally Posted by Gerald Koch
    BTW, by creating a large volume of solution you create the potential problem of spills and the difficulty of cleaning them up. Trading one problem for another.
    Handling liquids is preferable to handling solids 99% of the time. Any chemist will tell you this.

    Quote Originally Posted by Gerald Koch
    I would be inclined to look around for granular forms of these two chemicals.
    Yeah right. Nobody seems to be able to find it at a reasonable price in any form.
    art is about managing compromise

  5. #25

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    Quote Originally Posted by avandesande
    It is fluffy and sticks to things because of static charge.
    Interesting, the amidol that I used some years ago to develop nuclear emulsions was granular and easy to handle. Same for the pyrogallol. I have heard that there is a fluffy form of this too. BTW, by creating a large volume of solution you create the potential problem of spills and the difficulty of cleaning them up. Trading one problem for another. I would be inclined to look around for granular forms of these two chemicals.

    LD50 values show a considerable variation, being partly dependent on the animal used (mouse, rat, rabbit, ...). Aldrich Chemical lists that for amidol (rat) as 240 mg/kg; JACTDZ 13,330,1994. Interestingly that for hydroquinone is equal to that for Tylenol, 300 mg/kg. Tylenol being toxic to the kidneys and liver. Doses facit venenum. It is the dose that makes the poison. While we should respect chemicals we should not fear them. I have worked with americium and plutonium, two of the most toxic substances known. I say this not to brag but to make the point that I would have been out of a job had I feared them.

  6. #26

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    Quote Originally Posted by Gerald Koch
    BTW, by creating a large volume of solution you create the potential problem of spills and the difficulty of cleaning them up. Trading one problem for another.
    Handling liquids is preferable to handling solids 99% of the time. Any chemist will tell you this.

    Quote Originally Posted by Gerald Koch
    I would be inclined to look around for granular forms of these two chemicals.
    Yeah right. Nobody seems to be able to find it at a reasonable price in any form.
    art is about managing compromise

  7. #27

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    I have to agree with Gerald, having a similar background. Also, any chemical used as a dye in hair dyes is not likely to be immediately dangerous in gram quantities, although I concur it would be a bad idea to drink hair dye, developer, or use any chemical or chemicals in a manner that wasn't intended. As far as I can tell, amidol is simply a sensitizer or irritant at worst in any reasonable quantity and use.

    MSDS precautions are also based on sort of "worst case" scenarios, to help protect emergency responders under accident conditions where large quantities may be airborne, releasing fumes or vapors from fire, and so on, hence the famous "Lava soap" MSDS. If I were responding to a burning tractor trailer wreck that had spilled a ton of amidol, I'd certainly want a Level A suit as I rescued the amidol. I'd want a newspaper covering my work surface in the developer mixing area and gloves in the developer tray.

    That said, the Amidol I got from Artcraft is indeed more dense and granular than the stuff from PF, and contains khaki-colored lumps which appears to be the same thing - amidol. It also mixes up a rather orange color, darker orange than the lighter, fluffier, more consistently textured PF stuff. The Artcraft stuff is clearly filter cake. There's a thread over on M&P that said the Arcraft stuff stained prints, but I can't tell it compared to the same picture developed in any other developer (including PF amidol), including the base paper.

    So maybe give the Artcraft stuff a try.

    Steve

  8. #28

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    So i guess pipetting or filling a graduate over a sink isn't more sanitary or easier than pulling out a scale and weighing a solid.
    art is about managing compromise

  9. #29

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    Quote Originally Posted by Steve Hamley

    So maybe give the Artcraft stuff a try.

    Steve
    Been there, done that. My Artcraft amidol is fluffy and in solution it's blue.

    I agree with avandesande's statement: "Handling liquids is preferable to handling solids 99% of the time. Any chemist will tell you this."
    Tom Hoskinson
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    Everything is analog - even digital :D

  10. #30

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    I've done both, and sooner or later you will dribble or spill liquids and you will spill powders. Your handling practices and housekeeping are everything when it comes to chemical or radiological safety. I generally cover my work surface with newspaper and use a small paper on the balance pan. When I'm done weighing amidol powder, I take the small square of paper, slowly fold it up and pitch it in the garbage. When I'm done same for the newspaper and wipe the work surface.

    You should of course, handle powders deliberately to avoid airborne dust - "spoon" it out of the bottle rather than shaking the bottle, etc. You should also handle liquids with care if you want to minimize spills or dribbles.

    I just don't think it makes much difference for most photo chemicals if you have decent chemical handling technique and clean up when youre done.

    Steve

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