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Thread: Xtol Oxidation

  1. #21

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    On my 4 one-litre glass bottles (http://www.ikea.com/it/it/images/pro...E288434_S4.JPG) the Xtol prepared on 2013/04 is still cristal clear and develops perfectly. That's 8 months.

  2. #22

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    Quote Originally Posted by Alessandro Serrao View Post
    ...Xtol prepared on 2013/04 is still cristal clear and develops perfectly. That's 8 months.
    Isn't that 12 months?

  3. #23

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    Sorry, my fault.
    It's 2013/08

  4. #24

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    Today I've tossed these bottles to be on the safe side but they were still ok. That's almost 18 months.

  5. #25
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    Regarding the initial tests, pH makes a difference in the keeping qualities of just about any reductant. Sulfite is an antioxidant, and it also alters the pH.

    PE

  6. #26

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    Yes, the production of the orange color might be pH dependent.
    I hope to repeat the test later using sodium ascorbate solution buffered with borate to the same pH as the other solution that contained sulfite.
    It is also an assumption that all the ascorbate is oxidized before the sulfite.

  7. #27
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    Quote Originally Posted by Rudeofus View Post
    sun of sand, the difference in stability can be easily explained by the difference in tap water across the globe. People from Australia report, that their Xtol goes bad within days, while yours evidently lasts forever. The key issue seems to be Iron content of tap water. While Xtol uses a powerful sequestering agent (DTPA) to control the Fenton reaction, more Iron still means more remaining effect and less stability.
    I'm pretty certain that the lifespan of XTOL is somehow related to water quality and maybe its iron content. I've used XTOL both in the USA and across Europe and have experienced a noticeable difference in lifespan depending on location.

    It even seems to vary from building to building. When I was in Los Angeles living in a fairly old building I would constantly have problems with XTOL sudden death syndrome. After I moved to a newer building the problem went away.

    I have also noticed that XTOL may not react well with some containers that are supposedly made from stainless steel. Therefore I have completely abandoned the use of metal with xtol, except for my actual developing tank, and switched to an all plastic workflow. Since then all seems well; at least in my current location.

  8. #28

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    Quote Originally Posted by Harry Lime View Post

    I have also noticed that XTOL may not react well with some containers that are supposedly made from stainless steel. Therefore I have completely abandoned the use of metal with xtol, except for my actual developing tank, and switched to an all plastic workflow. Since then all seems well; at least in my current location.
    Are you suggesting the iron content of stainless steel catalyzes the Fenton reaction?

  9. #29
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    Quote Originally Posted by Rudeofus View Post
    I have no idea whether Adelaide is a big town or a small hamlet, but Dr. Croubie and some Mr. polyglot both report that their tap water kills Xtol. Since their water won't pass the metal detector for air transport, and I am afraid of standing upside down for prolonged periods, I have no way to confirm or deny this.
    Ha! Good one, Rudeofus! Maybe rotary processors go the wrong-way round, too. To be sure, I'm joking -- gotta get to Australia and New Zealand someday.

    As a side thought, some say Fomadon Excel developer is an XTOL clone. Has anyone heard reports of Excel crashing suddenly? I note Excel is available in quart packets, so perhaps the developer tends to get used so quickly no one lets it sit around long enough to turn.

  10. #30

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    Quote Originally Posted by Tony Egan View Post
    . I have always stored my XTol in "wine" bladders (usually 5 litre ex "pure" water bladders) and have never had a problem. Has been perfectly fine after 2 years in one case. I prefer my wine from bottles.
    Good to know Tony. The tap water in my area of the U.K. is particularly hard. Limescale forms around tap openings and kettles need descaling quite frequently. Despite this or maybe because of it, I have usable Xtol in wine bladders that is now 17 months old based on a film developed end of last month. It may be I can look forward to 2 years as well. I intend to use the leader test each time and if it goes black to the extent of dimming the tungsten wires in a clear light bulb to the same extent as when almost new then I'll continue with it.

    I'd urge anyone else to try wine bladders and the leader test

    pentaxuser

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