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  1. #11
    Rudeofus's Avatar
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    Quote Originally Posted by Gerald C Koch View Post
    When used alone ascorbic acid is very slow in its action and has a long induction period. For this reason it is most often used in a super-additive mixture with Metol or a Phenidone derivative.
    There may or may not be significant differences between the pictorial results of AA and HQ, but in respect to the above AA and HQ are very similar, at least for moderate pH levels.
    Trying to be the best of whatever I am, even if what I am is no good.

  2. #12

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    Quote Originally Posted by Rudeofus View Post
    There may or may not be significant differences between the pictorial results of AA and HQ, but in respect to the above AA and HQ are very similar, at least for moderate pH levels.
    My statement concerned the chemical properties of the two agents not the pictorial results although these are also different. Any resemblence between the two agents is superficial. For example, AA gives finer grain the HQ. As to the chemical properties the oxidation product of HQ, the monosulfonate, is also a devfeloping agent. This is not true for AA. Also AA produces little infectious development. There are other differences which I will not go into in this post.
    Last edited by Gerald C Koch; 06-20-2012 at 09:59 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  3. #13

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    Ah i never realised it could be used as an ACTUAL developing agent, I might give that a try, I don't reckon it would last long once mixed? like rodinal as Vitamin C is unstable Also, what about using a salt of ascorbic acid, such as sodium ascorbate? does it require the molecule ascorbic acid on its own or can it still do its action, bound to the sodium? Also what about ascorbic acid esters? I always knew sodium ascorbate to be more stable, at least I think it is...

  4. #14

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    In XTOL it is sodium isoascorbate. Not sure if that helps answer your question (I'm not a chemist).

  5. #15

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    Isoascorbic acid is slightly more active as a developing agent. This isomer is more commonly called erythorbic acid. The sodium salt of either agent can be used in developers and do not require added alkali as the acid does. Erythorbic acid also tends to be a bit cheaper. What does the developing is the ascorbate ion which is produced by either ascorbic acid (think hydrogen ascorbate) or sodium ascorbate when dissolved in water.
    Last edited by Gerald C Koch; 06-25-2012 at 10:19 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

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