Quince - 5-12-2006 at 06:42
I did solvent extraction from some plants with methylene chloride, then separated the oils from the wax with alcohol and vacuum filtration. Now
there's wax in the Buchner funnel and I've no idea how to remove it 
As a home
hobbyist, I don't have access to anything like Nochromix or chromic acid. I read that using sulfuric acid and peroxide should be avoided, and even if
I did, I'm not sure the wax won't just end up as carbonaceous soot that will be impossible to remove. So, what do I do? By the way, soaking in
methylene chloride which should dissolve it as it was what was used to extract it is not possible, as I don't have enough; the solvent recovery after
extraction went awry.
hinz - 5-12-2006 at 06:53
I would just heat it in an oven to 300°C or more, this should vaporise the wax, alias long chain alkanes. My buchner funnels are made of ceramic, I
expect your are also ceramic so there is no problem with heating it, maybe only the smell of vaporised wax.
Quince - 5-12-2006 at 07:15
I forgot the oil on the heat while evaporating the alcohol. Now it's all burned. So now not only is the Buchner dirty, but half the night and all my
source material have been wasted. I'm laughing now but I feel like crying.
My Buchner is glass, not ceramic, so I'm not sure how far I can safely heat it.
[Edited on 5-12-2006 by Quince]
DeAdFX - 5-12-2006 at 09:46
I wouldn't really recommend frying the wax out of the glass. I did the samething to a glass beaker and I ended up getting a char mark. Maybe I
heated to much I don't know but its worth a try. Try using potassium permanganate with semi diluted sulfuric acid.
YT2095 - 5-12-2006 at 10:07
gasoline/petrol will remove the wax quite nicely, even parafin or terps, bbq lighter fluid etc... and then wash in plenty warm soapy water.
unionised - 5-12-2006 at 12:45
I have cleaned sintered glass filters in a furnace before now.
"I did the samething to a glass beaker and I ended up getting a char mark. Maybe I heated to much I don't know but its worth a try."
If you heat carbon in air it burns off; but you need a fairly well controlled temperature to do this without risking melting the glass.
Solvent washing with petrol or some such is a better idea, but remember not to smoke while you do it.
Quince - 5-12-2006 at 18:57
OK I bought more paint stripper and distilled the methylene chloride. Soaking the Buchner in for a few hours got most of it, and the rest with
H2SO4+H2O2. Too bad I can't recover the burned oil...
Quince - 5-12-2006 at 18:59
I've another question. When I turn the ground glass valves on the Gregar while in use, some liquid gets into the joint and then they can get stuck.
This far I've managed to pull them out afterwards, but I'm always afraid of ending up breaking them. I can't use PTFE tape as in other ground glass
joints since it would cover the valve holes. What's the best way to deal with this?