Nitrox2
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Passing liquid through vacuum tubing?
Could 2 of these cold traps be used as a microscale distillation apparatus, and at vacuum???
By connecting the two tubes with vacuum tubing, and a tube to vacuum, could liquid essentially be distilled at vacuum, and condensed in the second
tube, assuming it is chilled in dry ice and acetone, and connected to vacuum?
[Edited on 13-6-2025 by Nitrox2]
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bnull
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What are you trying to distil?
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CouchHatter
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I agree, it really depends on what you're distilling. The physics of the idea work, but I doubt its efficacy. In my experience, lengthening the
condenser is more worthwhile than managing dry ice and acetone, unless your distillate NEEDS those extreme low temps. Are you talking about foregoing
a hotplate, and only relying on vacuum to boil the pot?
The relatively short path to vacuum could cause lots of vapors to bypass the "condenser" trap #2, since the surface-area-to-distance ratio is worse
than a traditional vacuum distillation setup. But for things which don't require a large vacuum, it might work decently.
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Dr.Bob
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Those will not work well for distillations, but can work OK. They make special small scale distillation heads, look at the 3 in the middle row of:
https://chemglass.com/distillation-heads are hard to use and expensive, see right most piece of this link
https://www.sigmaaldrich.com/US/en/product/aldrich/z558575
For very small amounts a Kugelrohr is used, they can do a few mls, similar to how you described above, but with a straight, short path between the
bulbs.
https://en.wikipedia.org/wiki/Kugelrohr
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BromicAcid
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Have seen that done before in the literature, i.e., material was distilled, material collected in the trap, trap was connected in series and allowed
to warm up to a new trap in dry ice to get a separate fraction.
On a more practical view, I have had plenty of times where I strip off solvents to our house vacuum (a valve on the wall that goes to our industrial
pump) and just to through a side-arm using vacuum tubing. It is much slower than a standard distillation because gasses take up a lot more volume
than a liquid so you're relying on this large volume of gas to go to your pump instead of having everything condense on the distillation side. I do
it but it's slower.
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Mateo_swe
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I would just buy a short-path distillation kit on ebay or similar.
You can find them from china for quite cheap and they work good, no hassle or problems.
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