Acid-Base LLE

As the title says, we tried the textbook NaOH base extraction with an immiscible solvent after a brine wash. We assumed that the acidic cannabinoids would partition at least slightly to the aqueous layer, but our yield was pretty poor. I imagine someone has tried this before and might be able to shed some light on whether this is a dead end or I just suck at my job. Help a fella out

I tried to search around as much as possible and the best I’ve gotten is people saying emulsions were problematic; we barely got any emulsion at all.

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My friend, who is a knowledgable chemist, played around with this and didn’t have much luck. Even if the acid form is soluble in water, I don’t think it’s THAT soluble. He concluded that it isn’t anywhere nearly as efficient as just doing a quick ethanol extraction.

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Yeah I’ve done it a few times.

It seemed good on small scale. Didn’t get nearly the expected results on larger scale. I wonder if I did some proper molar calcs and then did something like ultrasonic mixing on it. If it would work better.

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Cannabinoids respond well to gentle bases if you’re cleaning up color, remediating pesticides etc. NaOH is overkill, but if you’re trying to separate a mixture of cannabinoids from an organic layer, you need to look into the partition coefficients of the cannabinoid acids’ conjugate bases. Deprotonating that carboxylic acid will not magically make it hydrophilic and it will still have a strong affinity for the organic solvent; maybe try using a base that is not solvated in water, use another solvent that is immiscible in your organic layer (hint).
:no_entry_sign: :spoon:

If you want to try salting out, that is also an option but the method I know requires very specific alkaline monoamine compounds; unfortunately most smell horrendous and it’s not a very efficient process.

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Methanol? Would there be any benefit to using a base augmented methanol solution to be more targeted to acidic cananbanoids? Maybe a single LLE style pull to get most cannabinoids out, without pulling as many non-polars from the organic layer?

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I had success with the dimethylhexylamine, but like you said, yuck…

I was told that dimethyltriptamine would work.

Also, was deep down the DES wormhole at the time. Pretty sure a hydrogen donor like ammonia would work, I’ll try and find the research that lead us to that conclusion

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It’s possible with dcm. I used to have a write up how to do it. I removed it bc it’s pretty dangerous. You can literally harvest the thca from the crude solution with just a acidic extraction.

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I’ve got 2 gallons of it, good ventilation, and I live dangerously.

Wanna dm it? :stuck_out_tongue:

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Id be curious as well but mainly to extract CBDa

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@spdking Your DCM SOP was a really interesting read, I believe you put this method back up again due to you faith in user understanding of the current hardware and safety requirements. I enjoyed the write up.

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Oh, I guess this is pretty much what I was doing now that I read it.

I was using less of a water volume.

Is there any reason you opted for DCM over other alkanes like Pentane/hex/hep? Wouldn’t they serve the same purpose in this context?

I have had luck getting acidic cannabinoids to go into the aqueous phase using higher basic conditions. Suspending extract in a solvent with a lower polarity, then basify your polar layer up around 11 or so… pull the water off using sep funnel and do a second wash on the solvent with another 11ph rinse. Then acidifying the water to 5 to 6 ph caused cannabinoids to loose solubility in water and start clumping. You can then pick them up in a fresh solvent later for crashing or evaporation. It yielded about 60% of the cannabinoid mass with white Crystal’s.
Not great for large scale but was a interesting experiment. I came from isolating entheogenic alkaloids and it seems cannabinoids behave nearly opposite to an alkaloid salt/base as far as polar/ non polar solubility. Just not as efficient.

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It behaves kind of like a carboxylic acid. :wink:
Did you notice lower yields at higher pH?

At to high a ph it did seem like yeild dropped. The water solution seemed to clear up a bit when my ph meter was off and I hit 12.5.
It was a quick way to get white crystal from a total poop soup. I think multiple washes would help but it’s not really scalable.

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You can get way more out. There’s a trick to the pH and washes that does it…unless it’s perfect yes I’ve heard people Sid 60-80% extraction efficiency. I’ve also heard people say they figured out how to get almost all out … But that’s thier tech I don’t talk about.

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Dcm comes off very easily. And cannabinoids extract and solute with it but don’t like being in it…

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More-so than Pentane?

I just had a less than super successful thc-a pull. So just isolating variables