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Thca crystalline

BioBuddha

New member
Hello,

I was just looking for tips on making thc-a crystalline structure. I have talked to some people who say I can get a decent extraction just using a separatory funnel and hexane isomers. Other say I won't have any success unless I use column chromatography. If possible I'd like to hear my options while avoiding column chromatography. Seems super expensive and time consuming.

Has anyone heard of slow evaporation recrystallization? How does that work?
 

montroller

Member
saw this on http://summit-research.tech/p/treasure-chest and thought it was pretty interesting...

1. take 100 grams and add to approx 500ml hexane isomers, direct from any extraction. non decarbed and non winterized, however winterized can be used. but virgin extract is preferred.

2. take 500ml distilled water and add sodium hydroxide until ph of solution rises to 13.

3. now take the dissolved hexane and extract solution and place in sep funnel. add slowly the ph 13 water.

4. allow to separate until emulsion layer breaks.

5. separate water out. at this point the water at ph13 will also have the thca, as well as some other compounds have now converted to thca as well. some. the water itself is what you keep, and a second wash may be done on the hexane wash with water, but the yield is very small, and not worth the time.

6. take the ph13 thca water and now add hcl to bring ph to 4-7. around 4-5 is best from what we have heard. the thca will precipitate out and cloud everything up. this may also cause a small foaming to occur so mix slowly and be careful. this is a chemical reaction from two components that do not solute together and begin to separate naturally.

7. once that water thca solution is back to neutral add back to sep funnel. then add new clean hexane isomers in the same ratio into the sep funnel with the thca water.

8. allow separation and emulsion layer to break. the hexane isomers with absorb the thca and it will separate from the water. remove the water and just flush a tad bit of hexane solution as well. remove contents of sep funnel inot rotovap and evaporate hexane, then place slightly liquid thca/hexane wash in vacuum oven.

9. turn oven up to 160-180f and vac off for abut 30 minutes and thc crystals will form.


**** replace hexanes with DCM, we are currently using dcm with great results.
 

BioBuddha

New member
Yeah, I've actually reached out to the author for more information. He stated using the separatory funnel creates a good starting material for column chromatography. I think I'll ultimately go with using the funnel and seeing what type of crystals I am able to make with it.

Ultimately just curious if others have had success not using column chromatography. What type of process has everyone been using and what their results are.
 

Old Gold

Active member
I need to finish cleaning up a very similar extraction as posted above.
The NaOH solution caused a deep purple emulsion that I was able to freeze it and pour the liquids off of. This must've been either anthocyanins or sugars. Weird that anthocyanins would ever precipitate out of water, and they are supposedly purple around pH of 7, so I am leaning towards sugars or something. Maybe flavanoid pigments...
Otherwise, the basic aqueous layer had a beautiful bright yellow hue, while the nonpolar solution remained a rich amber.

It likely takes a good volume of water in relation to hexane to create water-soluble salts of carboxylic acids. Terpenes should remain in nonpolar solution - to be distilled later
I will continue with further NaOH washes and see what I can pull.
If THCa doesn't precipitate out, try extracting it with clean hexane again.

I will try to post some pictures soon.
 

Pangea

Active member
Veteran
Do you know the purity of you isolate after you clean it up but before you distill it? You are already cleaning with silica, correct? Why the assumptions on chromatography type fractioning being super expensive or time consuming?

HashoftheTitans, is using limonene and a modified closed loop, Id love to hear more about that!

Other wise I believe it was, GO Joe, who linked to a Dry Column Vacuum Chromatography post on erowid, that can be scaled to kilogram+ runs.

You just gotta utilize the silica in a different manner!

Slow evaporation vs quick will result in different crystallization outcomes which are primarily size of individual crystal and possible purity issues, generally the faster the crystallization the easier it is for things to go wrong. Ive read it being likened to a game of tetris, "Done slowly, there is time to rotate all the pieces and get the perfect fit. As you speed things up, it becomes harder to get the right fit, holes are left, and before long the whole crystal goes to the dogs. "

The purer the starting the point the better, thus chromatographic fraction or high grade bho, using a solvent that is GRAS or better is also recommended in case of occlusions, inclusions or adsorptions of your solvent into the crystals!
 

Old Gold

Active member
I will be doing a slow butane recrystallization tomorrow, starting material is acetone winterized BHO.

Can anyone (ahhhhem G.O. Joe) with real chemistry experience explain why different solvents, perhaps even with similar polarity index, may create entirely different crystal lattice structures?
I picture the way a solution would look as molecular sturctures, and as you get to the point of oversaturation/precipitation, the shape of the molecules would be like staggered Tetris pieces, with the solvent pieces floating away lol. Obviously, long straight chain solvents will create a different structure than, say, cyclohexanes. Almost like the frame of a building. Better explanation plz...
 
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BioBuddha

New member
How long does the slow butane recrystallization take? Do you purge for a while first? What container do you move it to? Do you open it to release pressure? How long is it left alone?
 

BioBuddha

New member
Do you know the purity of you isolate after you clean it up but before you distill it? You are already cleaning with silica, correct? Why the assumptions on chromatography type fractioning being super expensive or time consuming?

HashoftheTitans, is using limonene and a modified closed loop, Id love to hear more about that!

Other wise I believe it was, GO Joe, who linked to a Dry Column Vacuum Chromatography post on erowid, that can be scaled to kilogram+ runs.

You just gotta utilize the silica in a different manner!

Slow evaporation vs quick will result in different crystallization outcomes which are primarily size of individual crystal and possible purity issues, generally the faster the crystallization the easier it is for things to go wrong. Ive read it being likened to a game of tetris, "Done slowly, there is time to rotate all the pieces and get the perfect fit. As you speed things up, it becomes harder to get the right fit, holes are left, and before long the whole crystal goes to the dogs. "

The purer the starting the point the better, thus chromatographic fraction or high grade bho, using a solvent that is GRAS or better is also recommended in case of occlusions, inclusions or adsorptions of your solvent into the crystals!

This is all in theory. I have yet to do this technique, still reading up on it before taking the plunge. What potency starting material do you use? Is it BHO extracted? Winterized?

My information on column chromatography is from my old college experience and forums I've been reading. Trying to find a quick and cost effective way to achieve crystallization. Can't I have my cake and eat it too?

And I'm a little unclear by your post. Are you stating column chromatography is the best technique or slow evaporation is?
 

G.O. Joe

Well-known member
Veteran
The NaOH solution caused a deep purple emulsion

Maybe the starting herb has a positive Beam test?

Can anyone (ahhhhem G.O. Joe) with real chemistry experience explain why different solvents, perhaps even with similar polarity index, may create entirely different crystal lattice structures?
I picture the way a solution would look as molecular sturctures, and as you get to the point of oversaturation/precipitation, the shape of the molecules would be like staggered Tetris pieces, with the solvent pieces floating away lol. Obviously, long straight chain solvents will create a different structure than, say, cyclohexanes. Almost like the frame of a building. Better explanation plz...

Crystal forms are usually different because of the temperature, solvent of crystallization if any (meaning included in the crystal), seeding with a certain crystal form, and especially rapidity of formation. Different solvents with different characteristics like boiling point and solubility will affect all that. There have been many times with noncannabinoids where one sort of crystal precipitated and everything was left to sit as it was overnight, but the next day something completely different was waiting.
 
saw this on http://summit-research.tech/p/treasure-chest and thought it was pretty interesting...

Which hexane isomer should I use? All of them :) All of the steps up to the last one are just a wash to remove impurities and don't have much to do with crystallization. If you dissolve THCa in a nonpolar solvent and then slowly evaporate it, you should grow some crystals. Hexane probably isn't the best choice since the boiling point is near the melt point of THC. Pentane and dichloromethane would be better choices.
 

Old Gold

Active member
Maybe the starting herb has a positive Beam test?



Crystal forms are usually different because of the temperature, solvent of crystallization if any (meaning included in the crystal), seeding with a certain crystal form, and especially rapidity of formation. Different solvents with different characteristics like boiling point and solubility will affect all that. There have been many times with noncannabinoids where one sort of crystal precipitated and everything was left to sit as it was overnight, but the next day something completely different was waiting.

Thank you! I think temperature has A LOT to do with it, I didn't really think about that. Different solvents have differing enthalpy of heat.

What is a positive beam? Researching now..
 

G.O. Joe

Well-known member
Veteran
Simplified Beam test: extract herb with 91% IPA or other mostly dry alcohol for a few seconds, add to the filtrate a little NaOH or KOH, pre-dissolved (or not) in the same alcohol. Purple color instantly or in a few minutes indicates CBD, CBDA, CBG, CBGA.

An oxygen scavenger like sulfite is commonly added to aq. NaOH to prevent this kind of cannabinoid oxidation during the quoted less than ideal process. It should also be remembered that d9-THC and THCA is very sensitive to acid and the entire procedure is best completed as quickly as possible.
 

Old Gold

Active member
Could Zinc dust be used instead of sulfite?
Sorry to pick brains, but why would the purple crash out of solution? Very distinctly insoluble in naphtha and alkaline water. I could try to wash with muriatic and see if she dissolves, but now I'm just throwing things at it without any theory...
I smoked both the flower and the dabs from which I tried to crystallize THCa. It is certainly not void of THCa content... The purple emulsion was THICK. There was more emulsion than starting material ("shatter").
I think I may have over-acidified the final solution, causing a decrease in yield to zero, or simply did not use enough aqueous NaOH to protonate the carboxyl groups.
 

G.O. Joe

Well-known member
Veteran
Substitutes for sulfite are the metabisulfite or the product of that plus water - bisulfite. It reacts with the NaOH to make sulfite, so you need extra NaOH for that. A typical concentration in the lit would be 5% NaOH and 1% sulfite. There's a patent maybe from GW Pharma that's come up a few times and later in this post it uses maybe 40% NaOH but they didn't say anything about what's been found to be the ideal concentration both in NaOH and NaOH:THCA.

Maybe the emulsion is purple but it could be a mix of things. It doesn't take much CBD to make a lot of color. A way to prove the Beam happening or not would be repeating this exactly as before but in the absence of oxygen in and above the solution. The purple in the precipitate should go away in acid solution.

If the cannabinoids tie up most of the NaOH or maybe even not it wouldn't be surprising that it would be insoluble in nonpolar solvent or mostly water, or that it would be an emulsion because you've made pretty much soap.

This brings us to the solubility of CBD in NaOH where I have no clue. CBDA can dissolve in NaOH like THCA and probably better, but it has to decarboxylate before it can form the purple color. It does this over time not instantly. The CBD Beam product is probably insoluble in nonpolars and very possibly aq. solutions, and CBD and CBDA may to a large degree prefer certain concentrations of NaOH to pentane, but the attraction of THCA to organic solvent should be more since maybe THC is insoluble in NaOH. This is probably the basis for a separation method as I've speculated before and for which that patent uses DIPE.
 

Pangea

Active member
Veteran
How long does the slow butane recrystallization take? Do you purge for a while first? What container do you move it to? Do you open it to release pressure? How long is it left alone?

I vac my closed loop system after recovering to -22, to ensure a clean system, there is some butane in the oil forsure I dont further vac purge oil I use for crystallization but imo the terpenes are acting as the major solvent in an ideal single neglect tech type straight BHO crystallization, fire oil will be liquid with terps even properly purged, this type of oil is preferable for crystallization and in general. Crystals will form in I have done 1 - 3 month evaporation rates for trying to make big singles, but have recrystallized vastly quicker.

This is all in theory. I have yet to do this technique, still reading up on it before taking the plunge. What potency starting material do you use? Is it BHO extracted? Winterized?

My information on column chromatography is from my old college experience and forums I've been reading. Trying to find a quick and cost effective way to achieve crystallization. Can't I have my cake and eat it too?

And I'm a little unclear by your post. Are you stating column chromatography is the best technique or slow evaporation is?

I havent personally used any chromatography separation yet. I think it could be done quite cheaply and quickly. There is no best or better inherently with these methods. They are all just slightly different paths to the same basic result. Chromatography is a good way to purify your solution for easier crystallization, the speed you want to produce/evaporate them after is just a variable. I use BHO with no chromatography as it happens readily if you get some basics in line, but If I was to scale up crystal production I would be using chromatographic techniques to further purify so as to gain more control.
 

Old Gold

Active member
Ha! Amongst focusing energy on other things, my recent attempt at BHO recrystallization went beautifully, and then I got impatient & curious, which isn't always a good combination...

Initially, I took a pretty well winterized slab (6.5g), put it in the bottom of a glass jar. I then flooded the jar with cold, liquid butane. After 20-30 seconds, almost all had dissolved, and even upon stirring, some amber was left at the bottom. I assumed this to be remnants of heavier stuff I missed in my winterization/filtration. I transfered this ~500ml of liquid butane (thc dissolved) into a clean jar, and evaporated it in a well-ventilated area over the course of an hour and a half. What was left was basically an overlay of bubbles and bubbles, very evenly distributed throughout what still filled up about 300ml. The only traces of color were along the edges of these bubbles, very slight gold/amber.

I should have left that as is, as long as possible. Instead, I was immediately curious enough to try again with a slower evaporation at slightly colder temperatures, but somehow the end of my evaporation melted the bubbles together. The first attempt was on its way to stabilizing the way it was. It would have surely made some clear prisms of some sort I imagine.
I'll give her more goes. There is heptane and naphtha around...

I'm sure cold iso-butane or propane would be friendly for the cause, especially if from a fresh, winterized extraction
 
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H

HemperorsKnight

Anyone have any video links that may help explain the actual process with what solvents and chemicals would be best specifically a method that won't result in a final product all filled with toxins
 
I think ph is where its at for doing thca extraction..

It still seems to me that it would be quite difficult for a company to pump out large amounts of thc-a crystals through simple evaporative crystallization. I think acid/base extraction MUST be involved at some stage of the process.

Also when seeing test results at 99.9997% THCa (the guild) you've gotta wonder how they seperated out other acidic cannabanoids that must crystallize with thca in some amount.
 
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