Does phenidone in propylene glycol just last forever?

Discussion in 'B&W: Film, Paper, Chemistry' started by ntenny, Sep 26, 2010.

  1. ntenny

    ntenny Member

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    I have a Mason jar of phenidone solution in propylene glycol (I use it mainly for PC-TEA). I'm not an extremely high-volume shooter or anything, so the solution, which must now be close to two years old, looks like lasting for a good many more to come.

    As far as I can tell it's lost no activity in that time, but it must have *some* limits on its lifetime, mustn't it? Has anyone ever had phenidone in glycol go bad, and if so, how long does it take (and can you tell anything by inspection)?

    Thanks

    -NT
     
  2. Ian Grant

    Ian Grant Subscriber

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    It should last a long time. As there's no water present it should last nearly as long as if in powder form, and that's decades :D

    I only finished the last of my first batch of Phenidone 2 or 3 years ago which I bought in 1976, that had Ilford's date code of 1962. Others have found the same.

    Ian
     
  3. Gerald C Koch

    Gerald C Koch Member

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    I never really worried about phenidone oxidizing until I openrd a jar that I hadn't used in over a year and found that it had turned to a brown tarry mass. The phenidone was in the original plasic container. So it will oxidize although in a glass jar I have keep it for 20 years.
     
  4. Ian Grant

    Ian Grant Subscriber

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    Good point about plastic containers, I've seen Pyrocatechin oxidise in the early plastics they used to store chemicals. They breathe oxygen albeit slowly, while a glass jar is fine. Higher density plastics been used much more since the 80's and these are almost as good as glass.

    Ian
     
  5. nworth

    nworth Subscriber

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    The simple answer is no. Over time the solution will darken and go bad. I've tried it once, and it only lasted about six months before it looked unreliable. Other people may have better experiences. My experiences with the powder form in plastic bottles has been decidedly better than that of those above. I had a bottle that lasted almost 10 years before it got used up, with only a very slight darkening over that period and no loss in activity.