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  1. #11

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    It's strange. Ascorbic acid is ascorbic acid. It could be that it lost activitiy on storage, which would be unusual. Otherwise I would guess that it may have absorbed some water.

  2. #12

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    Quote Originally Posted by jim appleyard
    I can get ascorbic acid at my health food store for $16/lb; pricey, but convienient. Is Trader Joes an online outfit, or a retail chain or something completely different?
    Trader Joe's is a specialty retail grocery chain that started in Pasadena, Ca, spread over the West Coast and now has locations on the East Coast. I have, on occasion, patronized the one located in Cambridge, MA.
    Tom Hoskinson
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    Everything is analog - even digital :D

  3. #13
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    Trader Joe's is pretty good, the closest one to me is in the Washington DC area
    Mama took my APX away.....

  4. #14
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    Quote Originally Posted by Tom Hoskinson
    Interesting - and expensive! A pound of Trader Joe's 99% pure ascorbic acid powder is about $6.00.

    There may be a clue in the description of the C1000. "Ingredients
    Vitamin C: 1000mg." The total weight of the product is 17 ounces??
    Our Trader Joes has it for 9.99 - I wish it was in larger quantities.
    My photos are always without all that distracting color ...

  5. #15

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    Your local Homebrew Beer and Wine supplies outlet will
    likely have ascorbic acid. Many via the WWW do. As a last
    resort Photogaphers' Formulary and others of our specialty
    chemistry suppliers do have it. Dan

  6. #16
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    Quote Originally Posted by psvensson
    I just ran out of the NOW Foods Vitamin C I've using ever since I started making my own developer last year. The replacement is of The Vitamin Shoppe's house brand, which is also supposed to be pure. It's a finer powder, which means it mixes faster, but I've noticed it's weaker than what I used before. I need 40% more by weight to make the film developer as active as with NOW Foods Vitamin C.

    What does this mean? Is the VS powder getting old, or is it just slightly oxidised from the start because it's a finer powder? Anyone else noticed differences between brands?

    I mix the vitamin in just before development, so there should be no issues of impurities that would cause instability in stored solutions.
    [font=Times New Roman][size=3]Which form of Vitamin C did you use previously? If you had Sodium Ascorbate, then you are now making developers that are more acidic than before. Developers containing Ascorbic Acid need to have more alkali added to get them going compared to those containing Sodium Ascorbate. For more info, follow this link to an article on Vitamin C developers by Pat Gainer:[/size][/font]
    [font=Times New Roman][size=3]http://unblinkingeye.com/Articles/VitC/vitc.html [/size][/font]

    [font=Times New Roman][size=3]If you still have your old Vitamin C container, you might want to check the label to see which kind you had.[/size][/font]

    [font=Times New Roman][size=3]Hope this helps...[/size][/font]

    [font=Times New Roman][size=3]Mike Sullivan[/size][/font]
    When the chips are down,

    The buffalo is empty!!!



  7. #17
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    Quote Originally Posted by psvensson
    Titrisol, they're saying its 1000mg of Vitamin C per 1/4 tsp, same as NOW Foods. That doesn't really leave space for filler. 1/4 tsp weighs 1g.

    I thought erythrobic acid was isoascorbic, i.e. an even mix of the enantiomers? Or are you using what's left over after they extracted the L-form?
    Ascorbic acid starts with a 6-carbon sugar. The sugars dextrose and levulose are mirror images of one another. One produces L-ascorbic acid and the other D-ascorbic acid. If you used a mixture of the sugars to make ascorbic acid, I don't think it would be very easy to separate them. The body knows how, but it doesn't tell us.

    I got a big bucket of D-ascorbic acid, also called isoascorbic acid or erythorbic acid. I have not seen any difference in any aspect of developing film or paper. I guess film isn't as smart as our bodies are. If they were really smart, we would be able to make our own vitamin C like gerbils, cats, dogs, and just about everybody but primates do. Then we probably would not have learned that it can develop film. Oh, well.
    Gadget Gainer

  8. #18
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    Quote Originally Posted by Jordan
    It's strange. Ascorbic acid is ascorbic acid. It could be that it lost activitiy on storage, which would be unusual. Otherwise I would guess that it may have absorbed some water.
    Ascorbic acid combines with oxygen to make dehydroascorbic acid and water. Dehydroascorbic acid will not develop film. Nothing in our developers can change it back. The hydrogen atoms that are used up are not the one that makes the acid acidic. Chlorine and bromine and a bunch of other things also make dehydroascorbic acid out of ascorbic acid. I think these are things they call "free radicals".

    I don't think there is a color change with this reaction. Sodium ascorbate gets very yellow with exposure to air and moisture and begins to smell like brown sugar.
    Gadget Gainer

  9. #19

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    Quote Originally Posted by Zathras
    [b][font=Times New Roman][size=3]Which form of Vitamin C did you use previously? If you had Sodium Ascorbate, then you are now making developers that are more acidic than before.
    No, it was the acid form.

  10. #20
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    Quote Originally Posted by psvensson
    No, it was the acid form.
    What about your phenidone solution? Could it be headed south?

    Mike
    When the chips are down,

    The buffalo is empty!!!



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