chemrox
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soxhlet modification
I want to modify one of my smaller soxhlets for leaching a gummy product into a boiling LAH solution. I suppose I could dilute the material in THF
and add it the normal way but I'm copying a procedure most of us have read in PiKHAL using very similar ingredients and it seems to work well and
conserve solvents too. Rather than have the soxhlet collect and dump the idea is to have it continuously drip and I think the way to do this to take
a torch with a fine flame and shrink the siphon tube until it closes. It would probably be best to do the shrinking closest to the bottom of the
lower end. Is this they way you would do it? (The glass shop takes too long for small jobs I can do myself.)
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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peach
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Be really careful with the soxhlet thing. If you can dissolve whatever you're adding in one go and use an addition funnel, that'll be a lot easier to
control and safer. If you haven't already, I'd recommend you try dissolving some in warm THF to check out the solubility for yourself. There are
examples of people using the soxhlet and it dumping a lot of their substrate straight in; it'll get real hot, real quick. The reaction will start
pouring heat out and the soxhlet will only speed up in those cases.
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watson.fawkes
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Look up the Gregar extractor. It has a mode of operation much like you're describing.
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safety first
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Trying a pipperine extraction from black pepper I observed that a small cotton wool plug at the the bottom of the extraction chamber produced this
effect. the solvent drips slowly and steadily throughout the extraction. if the substance is not too viscous it might work. You have to regulate the
heating or the thickness of the material a bit but it would probably work just as well with glass wool or something else non reactive. Hope it helps
[Edited on 25-6-2012 by safety first]
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Paddywhacker
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That's a waste of a good soxhlet, which is OK only if you can afford it.
But, for a continuous extraction, how about suspending your soxhlet thimble in a wide diameter air condenser or chromatography column with a regular
condenser on top, the whole lot mounted above your boiling flask.
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Mildronate
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Interesting, i have something similar to Gregar extractor, its old soviet custom extrator from radiochemistry lab, it also had porous glass.
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chemrox
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@Paddywhacker (I hope the username doesn't imply disdain for those of us of Irish descent!?) Thanks! That's a good idea and one I've been thinking
about it. A cylinder wide enough for a 50mm glass thimble, a 24/40 and a 55/50 joint should do it. The glass thimble would sit inside no need to
suspend. Cool!
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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