Ragnarok
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Methylene blue
OK... Here it is:
I need some fairly large amounts of ethyl alcohol for some plant extractions. And, being the cheap s.o.b. i usually am, I don't want to pay the fairly
large alcohol taxes included in commercialy available 85% ethyl alcohol I can buy in a supermarket. So a logical choice arises - the way cheaper 70%
"medicinal" alcohol.
Only problem is it's colored with methylene blue and has ethyl salycilate added. The ethyl salycilate is easy to get rid of (NaOH in the rbf and it
should turn into sodium salycilate and more ethyl alcohol - YAY!). The tough part would be the methylene blue. My only references say it melts between
100 and 110 deg. C and decomposes. Is it stable in my under 100 solution (but with localized overheating)? Also, what it decomposes into would be of
interest too. Anyone having any experience with the stuff?
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crazyboy
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I believe methylene blue can be removed by running the solution through a column of activated carbon. I saw a demonstration once...
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Nicodem
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Methylene blue can only be carried over in the aerosol, but this is no problem since you will use a distillation column if you need 96% ethanol.
PS: The thread is moved to Reagents and Apparatus Acquistion where more appropriate, and where numerous threads about ethanol purification and
de-denaturation already exist.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Ragnarok
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So it won't decompose into assorted nasties during distillation?
Sorry about the misplacement... I'm sort of new around here 
Thanks for the help!
[Edited on 13-6-2008 by Ragnarok]
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