Shelf life of 1% solution of Phenidone

Alan9940

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Does anybody have any guesses as to how long a 1% Phenidone solution mixed in propylene glycol will keep at about 60F?

Thanks!
 

koraks

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Anon Ymous said:
Years in my experience.
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Sure.
It'll be apparent when it has started to deteriorate as it will start to take on a color. Pale yellow at first, and darker as it goes off. This will take a loooooong time in glycol. In ethanol, the start of deterioration is visible in a year or so.
 

Don_ih

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I mixed mine in denatured alcohol and it seems to have died in about 2 months - maybe a bit less. (I don't have any prop.glycol or I would've used that).

Thin negatives = bad way to find out your stuff isn't working.

Also, it doesn't appear to really be a different colour than it was when I mixed it - maybe slightly darker.
 

revdoc

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I recently noticed that my 4% phenidone solution in glycol has finally died. It took about 4 years.
 

Fatih Ayoglu

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Is Glycol better option than Ispropyl Alc, when preparing developer solutions? In my case Muir SoftShot.

As Phenidone does not dissolve in water easily, the suggestion was to use Alcohol, but if Glycol is better, then maybe I should use that.

How long does it last in Alcohol? Weeks? couple of months?
 

Don_ih

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Fatih Ayoglu said:
the suggestion was to use Alcohol
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I'm getting to be of the opinion that alcohol is fine for dissolving the amount you need to use and using it right away. All evidence points to glycol being the best option for making a solution to store.
 

koraks

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Fatih Ayoglu said:
Is Glycol better option than Ispropyl Alc, when preparing developer solutions?
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Glycol is better for making a phenidone stock solution. Ethanol is more problematic for a few reasons and you see this reflected in a significantly shorter lifetime of the concentrate. Once the working strength developer is mixed, there's no practical difference anymore.
 

Fatih Ayoglu

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I need to mix 2% and Ctein says the stock solution (used Alcohol) can stay for 6 months, maybe it is not that long.

Ok, now time to order some Glycol
 
OP
OP

Alan9940

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Steve Goldstein said:
Is there any value in heating the glycol to drive off any residual moisture?
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Don't know about driving off residual moisture, but I've found that heating the glycol to about 140-150F really helps in dissolving the Phenidone.
 
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