Preparation of crystalline THCA

[hash head]

One of my coworkers at the collective got some 99% cbda crystals at a cannabis cup. They were bright white. I took a 200mg dab and it did not have any considerable effect on my chronic back pain. He paid $100 for the gram. After reading this thread i am wondering if it was cbda or of it was already decarboxylated during their process and they just claimed it was cbda.
One thing i noticed is that the bits that melted to the dabber turned back into exactly the same crystals when they cooled. It was quite different than when you have melted shatter on ur dabber and it never gets back to its original clarity.

Could it be some kind of non cannabinoid salt? Just sounds like it how it turned back into the crystals

 

[weedaholic721]

^^ Unlikely, Even sugar will recrystallize with melting and cooling. If it's pure enough, the crystal form is lower energy state.

 

[hash head]

After experimenting with ph.. I'm starting to think that column chromatography is the best way to isolate thca.. anyone have any experience doing column chromatography with ethanol or limonene as mobile phase? Can get a cheap column for $20 and experiment... load with silica gel and see if layers seperate... rotovap each layer separately and hopefully end up with a clean thca fraction

 

[TerpChild]

It said 99% pure cbda crystals by Nameless Genetics. They were bright white and would return to that state at room temp. Wondering if we should have just eaten it as smoking it did not seem to decrease the inflamation in my discs. Anyone else have a experience with both inhaling and eating cbd and which is better? Or are topicals the best for cbd in terms of inflamation reduction?

 

[Zapadra]

I would personally pick pentane and that is what we mostly use these days instead of hexane.

Agreed.

 

[SkyHighLer]

I used to have an Acme 6001 stainless steel centrifugal juicer, seems to me it might be useful for experimental purposes. Either to spin up some high THC-A laden oil to see if the THC-A crystals can be coaxed out, or to do some on the cheap centrifugal partition chromatography by packing the screened basket with your filter material, and squirting measured amounts of solvent into the spinning basket at intervals.

It can be operated with the top off as can be seen in this video,

https://youtu.be/LvBoQNVaLJI

You should be able to wash down the individual partitions with some extra solvent from a lab wash bottle while keeping it running. The switch is the only source of ignition, tape it in the on position, and switch it externally.

You could probably also use it to filter winterized oil, by pre-freezing the basket lined with filter paper.

Pic of the basket

^ Used SS Acme 6001's are cheap at eBay, they're extremely robust, should do you fine, but it's still available under the Waring Commercial brand,

https://www.amazon.com/6001-Juicerator-550-Watt-Extractor-Stainless/dp/B0028RXDFM

At that page I noticed they have filter strips to line the basket,

https://www.amazon.com/Replacement-...9_1?ie=UTF8&psc=1&refRID=GKB79APDXC7JS3CJHJJG


You might want to slow it down, should function fine with a 120V 10A or higher rated Variac, also something you might consider getting used,

https://www.amazon.com/Circuit-Spec...3&sr=8-2&keywords=variac+variable+transformer

If you run it with the top off, use some tape or bungee cords, whatever, to hold the collection pan more firmly in place, you don't want the spinning basket scraping against the pan when working with flammable solvents. I say that because I just know someone's going to try filtering sub zero butane through it, just covering my ass.

^ All kinds of things you could try with it, how about thickly packing the basket with "acid-washed see-sand (Sigma) and topped with glass pearls (±1 mm diameter)?"

"3.2.7 Separation of acidic and neutral Cannabinoids

A glass-filter (mesh size 2) of about 5 cm in diameter and 7 cm in height was filled for 2/3 with acid-washed see-sand (Sigma) and topped with glass pearls (±1 mm diameter). Before use the sand was sequentially washed with 200 ml of hexane, ethanol and water. Cannabis hexane extract was concentrated to about 5 ml of hexane, placed drop-wise on top of the sandfilter and evaporated by using a warm air blower. The sandfilter was then placed onto a suction Erlenmeyer and acidic cannabinoids were eluted by washing the sandfilter under vacuum with a 0.1 M NaOH solution. The elution was continued until the eluate turned from deep-orange to colorless. Neutral cannabinoids and other compounds were then eluted with ethanol (200 ml), followed by hexane (200 ml). Acidic cannabinoids were precipitated in the aqueous eluate by adding HCl until the pH reached 2 and then filtered through the (dried) sandfilter. The precipitate that remained on top of the sandfilter was finally eluted with ethanol (200 ml). Neutral and acidic cannabinoid fractions were both concentrated into a small volume by evaporation under reduced pressure and analyzed by GC and HPLC."

https://openaccess.leidenuniv.nl/bitstream/handle/1887/12297/Thesis.pdf

^^ You could even do the initial extraction with an Acme SS centrifugal juicer:

1) Line the basket with a couple of the filter papers I linked to above, wet them with solvent.

2) Grind your herb through the machine like you would fruit or vegetables.

3) (optional) Freeze the basket with the ground herb (it should be a solid 'cake' on the inside of the basket,) and the heavy cutter/shedder plate. Plastic bag them so they don't pick up moisture. Freeze the solvent.

4) You can either pour the solvent through the plunger opening on the lid; or run it without the lid, and squirt solvent with a wash bottle.

The above post used hexane for the initial extraction and elution, why not use pentane, less smell, and a safer Class 3 rather than Class 2 food and drug solvent.


Should be good for a super cold ethanol quick wash? And then hit it again with room temp solvent for oral meds.

^^^ Another, wetted paper filter in the Acme 6001 basket, dump activated carbon (charcoal) powder through the plunger opening to form a thick packed filter, hit it with your oil solvent solution and out comes, near clear?? And with way less solvent/oil loss than a Buchner.

On that drift, line the basket with a one micron sock filter...

Or line the basket with a really 'tight' filter, and you can filter mold without the hassle of syringe filters.


I didn't see anyone using a centrifugal juicer as a DIY centrifuge at YouTube, maybe underground chemists are aware of the idea, has anyone run across it?

The bee keeper/bio diesel guys have a basic centrifuge design, see the video link below, and unless I'm missing something, you'd get the exact same action by blocking the Acme 6001's basket's filter screen with something, and pouring solvent/oil slowly down the plunger opening... the unit is designed to handle overflow, it will catch in the lid bulge, and flow down and out through the spout.

The Acme 6001 runs at 3,600 rpm, and if you use a Variac as mentioned in one my posts above, you can overdrive it by as I recall, about ten percent along with varying the speed.

https://youtu.be/PsLGX-RbKuQ

^ Found a Youtube video of how to do just what I described above to filter waste vegetable oil, the Omega 1000 is very similar to the Acme 6001,

https://youtu.be/rS26K9xt3Zg

Picked up a new Omega 9000 from Amazon, $130. The matching Omega paper filter strips, another $16.

https://www.amazon.com/gp/product/B00ZG1BVYC/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Other than to make up a couple of hook ended mini bungee cords to hold the shell down when I use it with the lid off, good to go!

I've been suggesting others examine their electrical devices before using near solvents, so here's some pictures of how I went over the Omega 9000.

Four Philips head screws on the bottom, and you're in. The bottom bolt and nut support the lower motor bearing, no need to mess with them. I bypassed everything, soldered the motor leads to the power cord's, and sealed liberally with heat shrink tubing, notice they choose to leave the motor ungrounded though there's a ground lug attached to the lower bearing support, I gave it some thought as to shorts and melt downs, and decided to leave it ungrounded.

Devices like this should be isolated under a fume hood or taken outside.

 

[SkyHighLer]

Some mini bungee and a couple of picture hangers, and it runs just fine with the lid off. It could even be used this way if you're willing to put up with a very light splatter at the top edge, or want to go to the trouble of either extending the wall a little with a narrow strip of plastic, etc., or maybe creating a barrier bead at the top with a slit piece of aquarium bubbler tubing.

Or the lid could be modified by removing the throat completely (it's tack welded in place,) or cutting a slit in the throat so you can squirt a stream of solvent up and down the basket.

I'll reconsider it after I get the basic testing with the lid on going.

 

[Whosayingkazam]

Is there a suggested method for recrystalization of ThcA that you would recommend or any literature I can read up on

 

[Old Gold]

http://web.mit.edu/x-ray/cystallize.html

Pick your poison. That's not a Holy Bible for crystal growth, but should send you in a few positive directions...
Essentially all of the methods discussed are being used for THCa at this point.

 

[SkyHighLer]

Basics of recrystallization,

http://libgen.io/ads.php?md5=EA63250BE43386C06B4BAE9A9A5C328A

Go to Chapter 13.

Organic Chem Lab Survival Manual: A Student's Guide to Techniques by James W. Zubrick, 2012, 9th edition.

 

[Whosayingkazam]

Thanks what perferdered solvents would you use for recrystalization I have a lot of starter seeds from Pangaes method and would like to clean them and recryst them aswell

 

[Old Gold]

Thanks what perferdered solvents would you use for recrystalization I have a lot of starter seeds from Pangaes method and would like to clean them and recryst them aswell

Me found some nice ones myself recently

Try putting them on a filter and washing with small amounts of super cold pentane or hexane?

 

[SkyHighLer]

Cyclohexane might be worth a try, freezes solid at only 44F. (I know because I forgot and stuck the bottle in the fridge.)

Melting point 6.47 °C (43.65 °F; 279.62 K)
Boiling point 80.74 °C (177.33 °F; 353.89 K)

 

[Ethan604]

-

 

[dybert]

Finally made some breakthroughs in the lab last week...

 

[Old Gold]

Macroscopic pictures don't speak a thousand microscopic words, unfortunately. Looks great though! Are those processed differently, or are the white crystals washed versions of the previous yellow chunks?

 

[DL1943]

dybert - would you care to share your methods and solvents used?

my question for pangea or anyone else that wants to weigh in - is there a reasonable way to produce thca isolate anywhere from 90%-99% using low quality shatter that has sugared? i am starting work on cleaning up some shitty slabs, and while i am likely just going to be winterizing, this thread makes me wonder if i can take advantage of the crystallization that has already occurred and produce a bit of isolate, but there isnt any seperation happening, the oil as is isnt pure enough, so its just a big mass of sugar goop.

i currently have a small jar with about a gram of the oil that i diluted with essential oil to mimic terpene content, mixed well, and added a small dab of the unmixed sugar was as a kind of "seed crystal", but its not really a crystal, and there might be to many impurities for seperation to occur.

dybert - im very interested in your method since your starting material seems to be a much higher quality version of what i am working with...a mass of tiny crystals, rather than the larger seed crystals which can be mechanically washed over a filter or with very minimal agitation.

 

[SkyHighLer]

Video of Kate Welch, Pharm D and Skunk Pharmers at PSU,

https://skunkpharmresearch.com/2017/06/09/video-of-kate-welch-pharm-d-and-skunk-pharmers-at-psu/

https://youtu.be/NudRsTb4sb0

By the time you get to the end of the video you'll know in relative detail the most efficient process for producing THC-A and CBD-A crystals.

 

[Old Gold]

Video of Kate Welch, Pharm D and Skunk Pharmers at PSU,

https://skunkpharmresearch.com/2017/06/09/video-of-kate-welch-pharm-d-and-skunk-pharmers-at-psu/

https://youtu.be/NudRsTb4sb0

By the time you get to the end of the video you'll know in relative detail the most efficient process for producing THC-A and CBD-A crystals.

I think Joe can doe better than he did with those solvent washes.... calling you out, Joe!!

 

[whatthe215]

Regarding Joe's mention of centrifugation. An actual CPC (centrifugal partition chromatography) or a traditional lab centrifuge?