Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
Soxhlet uses for extracting compounds?
I was wondering if soxhlet could be used in some ordinary chemistry applications except extracting compounds from vegetables? For example, it would
allow to dissolve compounds with very small volume of solvent and it will recrystallize directly in the flask?
|
|
|
Fery
International Hazard
Posts: 1015
Registered: 27-8-2019
Location: Czechoslovakia
Member Is Online
|
|
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
|
|
|
macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline
Mood: Electrical
|
|
It can be used to separate a low yielding product from all manner of crud.
or to squeeze the last bit of yield out of a horrible sludge.
Extracting from precipitates is a primary example.
|
|
|
chemist1243
Hazard to Others
Posts: 170
Registered: 7-8-2019
Member Is Offline
|
|
Quote: Originally posted by Fyndium  | | I was wondering if soxhlet could be used in some ordinary chemistry applications except extracting compounds from vegetables? For example, it would
allow to dissolve compounds with very small volume of solvent and it will recrystallize directly in the flask? |
Yes, thats pretty much the basic idea of a soxhlet extraction - use as little solvent as possible to extract as much as possible. Weather something
crystallizes out on cooling depends on how much solvent you used and how much solute is in solution. Just make sure you use fresh glass wear on any
food related projects, not glasswear that has already had chemicals on it.
|
|
|
unionised
International Hazard
Posts: 5126
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
This is the "calassic" use of a soxhlet as a way to force a reaction.
https://www.prepchem.com/synthesis-of-diacetone-alcohol/
|
|
|
TriiodideFrog
Hazard to Others
Posts: 108
Registered: 27-9-2020
Member Is Offline
|
|
I used a soxhlet to extract piperine from black pepper and capsaicin from chilli peppers. I like to use the soxhlet as it is quite effective and also
reduces the use of solvent. I have also seen others extract many compounds using the soxhlet extractor, so I think it will work for you.
|
|
|
unionised
International Hazard
Posts: 5126
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
OK, technically that is extracting compounds from fruits, rather than vegetables but... I don't think it's what the OP had in mind.
|
|
|
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
Basically something alongside a situation where there is a compound that has very low (0.1-1g/100mL) solubility and it needs to be recrystallized or
purified from other stuff that has either nil or high solubility. So during long run, the fresh solvent leaches out little by little of the stuff, and
it collects in the boiling flask.
It would in theory allow to recrystallize stuff from very small amount in relation to solubility, and the temp curve doesn't matter in such way
because the solution will be anyways oversaturated within moments. Naturally, it would require that the substance withstands the temp of boiling
solvent.
|
|
|
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
I had a wild thought if acetone(or other) could be used to extract urea from ammonium nitrate with soxhlet? This same could be turned upside down in
order to remove the AN or other nitrate with a solvent where the other impurities are scarcely or nil soluble. A water bath to heat the solvent would
of course be used, in order to not create any hotspots.
Nurdrage video also had clips of his produced cyanide - how terrible idea would it be to puify the cyanide with methanol extraction? With effective
scrubbing and negative pressure fume hood it shouldn't pose excessive risk, if it does the job. I have the year-old batch of presumed NaCN stored
away, and if this could in theory work, I could give it a hit.
|
|
|
Boffis
International Hazard
Posts: 1867
Registered: 1-5-2011
Member Is Offline
Mood: No Mood
|
|
I have just run a soxhlet extraction of old dark green benzoquinone. I discovered something I hadn't thought about before in this context. I was
following a procedure given in Woodward et al's classic 1958 paper on the total synthesis of reserpine. In their procedure they purify benzoquinone by
soxhlet extraction of the crude material with octane (Bp c 125-128 C) so as not to introduce water (as would be the case if it were steam distilled).
I didn't have any octane so I used 99% n-heptane (Bp 97) The extraction started out really well but then benzoquinone began to build up in the
condenser because even at 97 C benzoquinone is very volatile. If anyone else ever tries this I would recommend going for cyclohexane or pet. ether Bp
range 60-80 or even 40-60 C. I will not completely solve the problem but should reduce it.
|
|
|
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
I would be counter-productive to attempt to purify higly volatile materials like that. They'd just reflux along with the solvent forever,
participating in the cycle.
Why ether is not used more, as it's very volatile and dissolves well? Using good condenser and airlock (like I do for acetone) will prevent fumes.
Btw, I should give a try for the cyanide purification. Shouldn't lose anything, and get pure(as pure as it is with co-dissolvents) NaCN with minimal
amount of methanol.
|
|
|
TheMrbunGee
Hazard to Others
Posts: 364
Registered: 13-7-2016
Location: EU
Member Is Offline
Mood: Phosphorising
|
|
Just a friendly reminder that pressure equalizing addition funnel + condenser on top = soxhlet extractor.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
