Was just thinking this might be a good idea. Save you a bunch of time in filtering the bulk of the ethanol? Is there stuff that needs filtering throughout the solution or does it all usually just drop to the bottom?
You really want to suck the fats dry and rinse them a bit. I’m sure the industry has its own method, but I’d think you would vacuum filter cold over celite with a jacketed Buchner, kept cold and sucked dry, and then to recystalise the fats to obtain the last bit of goods.
The sep funnel is going to suck all sorts of atmospheric moisture as soon as you start to empty it cold. Then a lot of fat is going to go right out the hole, and you are going to have lots of good stuff entrapped with your fats in the funnel still. So you’d have a fatty mixture of stuff you want in the funnel, and a wet mess of goods and fats in your receiving flask.
If you left it in the cryo environment long enough I think the fats would plug the valve, making you pour it out the top.
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Yeah I figured a self forming plug might be an issue
You could probably just duck tape dry ice to the outside of a normal Buchner
A dewar style Buchner would be easy enough to make I bet and way less ghetto. I don’t know if such a thing exists yet
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Yeah or maybe a dry ice/deep chill bed before it hits then buchner.
I think time plays a factor in it though?
(1) cold liquids exposed to air get very wet
(2) haste is in order to prevent warming and condensation of water
You can do it just be aware of what separates good tech from bad tech
Filtering it all at once increases the amount of time it’s exposed to atmosphere and how long it has to warm up, so we often filter cold stuff a little at a time, keeping the stuff-to-be-filtered as cold as possible and closed to air.
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I prechill my Buchner funnel. It is fritted. I am knowledgable about methods of removing “waxes” which is a term I use to indicate all substances that generally get pulled out and get called waxes. Most waxes are not pure molecules at all but for simplicity I will call it wax.
The way I chill my funnel is first I load the device with 3-4 inches of 220 grit aluminum oxide. I top it with a paper filter just for tidiness.
Then I fire up my cryogenic submersion chiller which can go as low as -87°C as measured at the probe. Into the expanded foam cryo tub goes my dewaxing alcohol of choice which is isopropyl alcohol when my other methanol procedure will not be run. This is a consideration that would take another thread to explain why I select what I do. With iso I can pre boil the mix on slow simmer and then let cool to room temp. This will tend to swell the waxes and gunk when I add 5-10% water to the iso and if controlled properly will also remove chlorophyl during this phase.
To prechill I place the flask with the disolved extract in it into the cryo tray. Another flask is just iso and water. Water is kept at a minimum for this process. I do have a room temp process that varies only slightly but the OP was about pre chilling or chilling the stuff to dewax.
When my thermocouple temp meter indicates -62°C or lower then I take clean solvent in the clean flask and flood the buchner with -62°C (nominal) solvent. It gets pretty slow and adding even a tiny bit of water will make it slower but it should stay liquid. Then I fill the funnel half full or so of the chilled solution of extract and iso. When it has pulled down to the top I fill it up again with clean and chilled iso/water to keep it all cold. It is important to carefully ensure you have only the bare minimum vacuum needed here. If you pull a strongth vac doing this when the isonis thick like syrup from being cold then the vacuum can and will just pull the chlorophyl right through too.
It is not inportant to save every last bit of extract trapped in wax compared to the clean up you get if you keep things very cold the whole time and keep the vacuum only high enough to keep the solution running. It can get very slow but so far just sticking to this recipe can do it. This is possible by prechilling the solution but also “recharging” the inline solvent temp to hold as close to -62° C as possible. At about -67°C and with admittedly poor control over ratio of water to solvent the funnel will begin to plug. No worries. Just start to flood it with a higher temp between fills to stop the stuff from going solid.
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Whats with the tp on the hot plate? I thought i was the only one who like warm tp.
Lol
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