Thanks a lot everyone
Once the crude is dissolved, you put it in the Pyrex dish and onto the heat mat. Let it evaporate until you see separation. Right? @YPSIOIL
Cuz I figured you were supposed to take it off the heat once dissolved and then let it evaporate at room temp for several days until separation happens. (Using the heat only to help the pentane dissolve the crude)
Forgot to mentionā¦ethanol also acts as a decarb catalyst, (peer reviewed) reference around here somewhereā¦
Maybe @moronnabis has it at his finger tips: Decarbing Diamonds - #20 by moronnabis
https://doi.org/10.1016/j.molstruc.2010.11.061
I think this may be one of the more detailed studies on Decarboxylation of Cannabinoic acid.
Since it seems ethanol always contains 5% or more
H2O , I can only say from my experience that decarboxylation will proceed in Ethanol solutions.
Exactly why I can not say with any certainty. But the above reference shows rates suggesting water catalysisā¦
How about a LLE wash with 0.01 N HCL to insure carboxyl group is in the R-COOH form.
If you are extracting with polar protic Ethanol from plant material you can be quite sure you are producing a extract with water and cannabinoate anion. Thinking you are going to evaporate and get anything but an amorphous glassine state off track.
Thinking about extracting with -50 butane/alkane aprotic -nonpolar and lucking out into a fast crash (deep unknowns) is so far different than extracting with a polar protic , you are in a different realm of chemisty. Have you ever even tried to measure the pH of your polar protic extract? What is it you want to crystallize. Most here just unknowly subject their ethanol extracts to some sort of ACIDIC CRC and unknowly convert the cannabinoate to the acid form.
sure, that would probably help. youāre right in that extracting with a polar solvent that natively contains water will probably result in a mixture of the carboxylate and carboxylic acid in the extract. but this 0.01 HCl approach would involve fully removing the ethanol solvent, redissolving in a solvent that is immiscible with water, drying, then removing the solvent again.
I have had success crystallizing THCA from ethanol extract without using acid. But it did involve removing ethanol fully and redissolving in pentane as the crystallization solvent.
Now I use a different approach altogether because the yields were crappy ^.
There is about a half dozen ways.
If you make tea with cannabis flowersā¦.just hot water teaā¦what do you think the pH will be?
I just do not know that many people who have even tried to measure the pH of their protic polar extracts.
Regards
@PolyC I would like to try this. To azeotropically distill out the residual ethanol levels, how do you go about doing that? Add pentane and then let it evaporate off or put under vacuum to evaporate off ? (In what ratio do you add the pentane:eho)
Do the whole thing in a rotary evaporator. After youāve removed as much ethanol as your system will allow you, add enough pentane to redissolve everything. Once dissolved, remove the solvent again. You can repeat this a few times if you like.
Essentially, the addition of pentane will reduce the boiling point of the residual ethanol from 78 C to 36 C. You can confirm that it is working by testing for residual solvents.
Interesting, What exactly is the mixture you put into the rotovap to evaporate on your first step.?
Is it raw crude Ethanol extract? Is this an extract of fresh frozen or dried cannabis? I assume you are using 95% etoh with Heptane added and extracting ādried biomassā. Even if your plant material is dry you are extracting the residual 8% water from the plant material. So you are rotovap -ing about a 10% water ethanol crude extract of cannabis biomass. Is the extraction a āsoakā or a ultrasound assisted extractā¦say 3 min or so? Iām just trying to understand what it is that your subject your rotovap pentane process to.
No winterization, charcoal or CRC? ???
When you roto vapā¦and add Pentaneā¦and you say you āredissolve everythingā. Do you mean that everything that a polar protic extract of cannabis biomass resdissolves in non polar aprotic pentane???ā¦.or do you mean redissolve every thing that is soluble in pentane, leaving a residual?
Is the endpoint a glassine crystalline form of THCA, is it diamonds, is it white chalk? Do you back wash the Pentane soluble mixture with any of the known methods reported on this site? ā¦and subsequently dry it to remove residual water?
I am just curious, not becasue I doubt what you say, but I am trying to understand the āformā or āformsā of the cannabinoic acids you observe/obtain to be crystallizing.
Interestingā¦.thanksā¦
We use 95% ethanol 5% water. Water will azeotropically distill off with ethanol and has never been an issue in this process. If these is any extra water absorbed from the dried biomass we extract, itās not enough to affect anything downstream. We use cold ethanol with agitation. No winterization, charcoal, or CRC, but we do filter it very well. Your dried biomass needs to be relatively fresh, i.e not decarboxylated.
Raw extract goes into rotovap. Remove ethanol. Add pentane and redissolve all of the extract (add enough to dissolve everything; it works). Remove the pentane, which distills residual ethanol with it.
The endpoint is THCA diamonds. The yield is poor, max ~30% (based on total available THCA). But you can recover and distill the mother liquor. And you really need to know your saturation point and have accurate QC testing to even get that yield. You also need general knowledge of the kinetics of THCA crystallization to develop the procedure.
I have already said a whole lot here so I better not add any more detail. It is possible to do this. It also sucks.
Thanks and most interestingā¦
If diamonds represent the dimer centered crystals reported in the literatureā¦sounds good.
So cold you mean -50 C. Or something like that?
And yes, if we want R-COOH/R-COO- we do not decarb!
So you have a resinous material in the trichomes=fresh biomass. You extract with ethanol and 5% h20ā¦to extract that resinous material. Polar Protic capisce? With out a doubt in the plant and in your solvent mixtures of acid and conjugate anion. You remove the solvent (effectively with as little of decarb as possible=no separation chemistry excepting the selectivity of your polar protic solvent)ā¦you remove the solvent and end up with something similar to the in situ resin all with the same acid anion ratio, because you have used the buffer imposed by the biomass.
Now you extract that with alkaneā¦which is identical (almost) to an original extraction with alkane (bho-like) and you get 30% diamonds and a mother liquidā¦containing 70% of your cannabinoic acids/anions.
I
Yep pretty much! The crystallization takes a long time.
When I mentioned non decarboxylated, I meant that you should test you biomass going in. If the THCA:THC ratio is <15:1, itās probably too decarboxylated. The decarboxylation rate of your dried cannabis depends on how itās stored of course.
Thanks! @PolyC
I put a cover on it for a few days