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Extraction of cannabinoid precursors with various solvents

Amml

Bluelighter
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Hey,
I would be curious about the solubility of various cannabinoid precursors (THCA, CBDA, etc.) in different solvents (ethanol, methanol, acetone, dimethylether, butane/pentane). Normally you would decarboxylate weed prior to extracting to get the active cannabinoids, but in this step also a lot of terpenes get lost and also the different plant ingredients start to react and may give unwanted substances in the extract. My solvent of choice would be dimethylether because of it's extremely low boiling point and non-toxicity.

I thought if it would be possible to extract the cannabinoid-acids and terpenes with a non-/ or weakly polar solvent and leaving plant sugars, proteins, etc. behind, you could heat the extract in a closed chamber. This would hinder the terpenes from evaporating and therefore may give a better extract while still decarboxylating the cannabinoids.

This also leads to one further question: Would it be possible that CO2 reacts with cannabinoids to form cannabinoid-acids again, or is this reaction not possible? (Temperature: 110°C, closed chamber with high CO2 concentration, elevated pressure)

Thanks in advance
 
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what you propose sounds logical, but I would try to get a rough estimate on how much CO2 will be produced and how much the pressure will rise when you decarb in a closed vessel...

furthermore, I highly doubt that cannabinoids can react with carbon dioxide to form acids... there are reactions like this, but usually, they require very high pressures, as far as I can remember from my OC classes.
 
Hopefully you find the information you're looking for! Here in CA, extracts are only decarboxylated if they are going to be used like an RSO, topical, or for some purpose other than smoking, with the exception of Frenchy Cannoli who does decarb his hash despite criticism from the newer extractors. Pretty commonly used is a mixture of butane and propane to achieve a good mix of properties, though single solvents are frequently used as well.

As for CO2, I think Bagseed is correct. Lots of supercritical CO2 extractions are being sold around here and there proponents seem to think they are all the shit.
 
what you propose sounds logical, but I would try to get a rough estimate on how much CO2 will be produced and how much the pressure will rise when you decarb in a closed vessel...

furthermore, I highly doubt that cannabinoids can react with carbon dioxide to form acids... there are reactions like this, but usually, they require very high pressures, as far as I can remember from my OC classes.

At first I thought of a closed vessel, but now I came to the idea to use a (open) glass tube with a cold finger that is heated up in an oil bath. That would avoid the risk of the possible reaction with the excessive CO2.
 
Hopefully you find the information you're looking for! Here in CA, extracts are only decarboxylated if they are going to be used like an RSO, topical, or for some purpose other than smoking, with the exception of Frenchy Cannoli who does decarb his hash despite criticism from the newer extractors. Pretty commonly used is a mixture of butane and propane to achieve a good mix of properties, though single solvents are frequently used as well.

As for CO2, I think Bagseed is correct. Lots of supercritical CO2 extractions are being sold around here and there proponents seem to think they are all the shit.

Supercritical CO2 extractions are usually done under room temperature afaik, but they also extract a lot of other plant components beside the cannabinoids and terpenes. Not sure if this is always beneficial…
Here in austria only low THC hemp (<0,3% THC) is legal and we also have a lot of extracts here, but it would be very interesting if there would be more information about the different hemp components in future :)
I already tried some supercritical CO2 oils and they had a much better effect for me than isolated CBD, but they also taste very nasty (probably because they are extracted from hemp and not marihuana).
It's also legal here to buy low THC buds, but they are far away from the smell and taste of high THC buds.
 
Hey,
I would be curious about the solubility of various cannabinoid precursors (THCA, CBDA, etc.) in different solvents (ethanol, methanol, acetone, dimethylether, butane/pentane). Normally you would decarboxylate weed prior to extracting to get the active cannabinoids, but in this step also a lot of terpenes get lost and also the different plant ingredients start to react and may give unwanted substances in the extract. My solvent of choice would be dimethylether because of it's extremely low boiling point and non-toxicity.

I thought if it would be possible to extract the cannabinoid-acids and terpenes with a non-/ or weakly polar solvent and leaving plant sugars, proteins, etc. behind, you could heat the extract in a closed chamber. This would hinder the terpenes from evaporating and therefore may give a better extract while still decarboxylating the cannabinoids.

This also leads to one further question: Would it be possible that CO2 reacts with cannabinoids to form cannabinoid-acids again, or is this reaction not possible? (Temperature: 110°C, closed chamber with high CO2 concentration, elevated pressure)

Thanks in advance

I believe terpenes are precursors to cannabinoids, what you refer to is just the inactive form of cannabinoid.

To avoid having waxes and lipids in your final extraction, there are filtration methods used that involve very low temperatures. I am not aware of any extraction method that uses a specific solvent to only remove terpenes and cannabinoids.

Being that THCA is converted to THC with heat and considering that pressure and boiling point are directly related, I don't see how it introducing a solvent at a high temperature and high pressure would do anything but further convert THCA and other cannabinoids into their active form, if not even further.
 
I believe terpenes are precursors to cannabinoids, what you refer to is just the inactive form of cannabinoid.

To avoid having waxes and lipids in your final extraction, there are filtration methods used that involve very low temperatures. I am not aware of any extraction method that uses a specific solvent to only remove terpenes and cannabinoids.

Being that THCA is converted to THC with heat and considering that pressure and boiling point are directly related, I don't see how it introducing a solvent at a high temperature and high pressure would do anything but further convert THCA and other cannabinoids into their active form, if not even further.

Yeah you're right I got that wrong. I meant cannabinoid acids like THCA, CBDA, CBGA, etc.
I'm also aware that even a non-polar solvent won't give me a pure cannabinoid and terpene extract, but my initial question was if it is possible to extract those cannabinoid acids with a non-polar or weak polar solvent and then convert into the free cannabinoids afterwards, or are they too hydrophilic because of the carboxyl group?

Regarding to the high pressure and temperature, I meant if it could be possible that the CO2 from the decarboxylisation reacts again with the cannabinoids?
 
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Maybe I'm not totally clear on what you are asking... Are you talking about extracting components like THCA and CBDA then converting them by chemical process into THC and CBD? Or are you asking if it is possible to isolate only cannabinoids and terpenes by chemical means? I'm not an expert in chemistry by any means but am fairly familiar with current extraction methods and trends. To answer the first question, yes it is possible but unless intended for ingestion not necessary. I believe most methods for making edibles would suffice. There are also other means for converting them, like heat during the smoking process, and I believe they are more stable in the first form. As far as isolation by chemical means, again not aware of any methods and simpler means are currently being used(low temps and micron filtration).

I'm not aware of any methods to convert THC or CBD back into THCA or CBDA. I would think if the goal is to obtain THCA, CBDA, etc. then it would be simpler to retain the components from the extraction rather than try and reverse the process.
 
Maybe I'm not totally clear on what you are asking... Are you talking about extracting components like THCA and CBDA then converting them by chemical process into THC and CBD? Or are you asking if it is possible to isolate only cannabinoids and terpenes by chemical means? I'm not an expert in chemistry by any means but am fairly familiar with current extraction methods and trends. To answer the first question, yes it is possible but unless intended for ingestion not necessary. I believe most methods for making edibles would suffice. There are also other means for converting them, like heat during the smoking process, and I believe they are more stable in the first form. As far as isolation by chemical means, again not aware of any methods and simpler means are currently being used(low temps and micron filtration).

I'm not aware of any methods to convert THC or CBD back into THCA or CBDA. I would think if the goal is to obtain THCA, CBDA, etc. then it would be simpler to retain the components from the extraction rather than try and reverse the process.

No, my actual question was if cannabinoid acids are as soluble in non-polar solvents (butane, dimethylether, etc.) as the free cannabinoids. My goal would be to extract those cannabinoid acids and then carboxylate them afterwards. This would prevent terpenes from evaporating and also other unwanted reactions that could happen during heating when plant material is still present.
 
Well considering that butane is commonly used as a solvent to extract cannabinoids, including THCA, THC, CBDA, CBD, etc, the answer would clearly be yes.

I don't follow your logic though, I don't see how decarboxylating or carboxylating cannabinoids would prevent highly volatile terpenes from boiling/evaporating. Preservation of terpenes would be done in the physical process of extraction and preservation of the extraction, not the chemical process. Methods for removing plant material from the extract use low temperature which causes the lipids to solidify and then they can be filtered out. Distillation is used to further refine and separate remaining plant material, cannabinoids and terpenes based on boiling point.
 
Well considering that butane is commonly used as a solvent to extract cannabinoids, including THCA, THC, CBDA, CBD, etc, the answer would clearly be yes.

I don't follow your logic though, I don't see how decarboxylating or carboxylating cannabinoids would prevent highly volatile terpenes from boiling/evaporating. Preservation of terpenes would be done in the physical process of extraction and preservation of the extraction, not the chemical process. Methods for removing plant material from the extract use low temperature which causes the lipids to solidify and then they can be filtered out. Distillation is used to further refine and separate remaining plant material, cannabinoids and terpenes based on boiling point.

Thanks for the answer. Without any special equipment afaik the plant material is heated on an open surface, which would cause the highly volatile terpenes to evaporate. Therefore it would be easier to extract the cannabinoid-acids first and then decarboxylate the extract in a closed chamber. Especially with low cannabinoid plant material (e.g. CBD-Hemp) this would be an advantage.
 
I see, basically you want to activate the cannabinoids and preserve as many terpenes as possible.

Some terpenes will evaporate at room temperature, which accounts for some of the instability of many waxes and partially explains why they sugar up over time.

I would think two separate processes would need to be used. One to extract and decarboxylate the cannabinoids, without major concern about losing terpene content. The other to reintroduce terpenes into the mix. Many extract companies already employ the reintroduction of terpenes for flavor, etc. There are also extract companies that only sell terpenes and most terpene profiles are available so one could replicate it fairly accurately.

I'm not currently aware of any simpler methods. Without using the process of fractional distillation, I don't know how you could separate the two. If you don't have access to advanced closed loop systems, you can refine an alcohol or butane extraction through a simplified process of winterization. basically using 95% food grade ethanol for extraction, you can then chill the solution in the freezer causing the lipids to solidify and clump up, then filter it through a coffee filter, then gently remove the alcohol. I think most of the common extraction processes will lose many of the highly volatile terpenes during the purge process as they typically employ heat and vacuum.

You would be on to something if you can achieve your goal though.
 
I see, basically you want to activate the cannabinoids and preserve as many terpenes as possible.

Some terpenes will evaporate at room temperature, which accounts for some of the instability of many waxes and partially explains why they sugar up over time.

I would think two separate processes would need to be used. One to extract and decarboxylate the cannabinoids, without major concern about losing terpene content. The other to reintroduce terpenes into the mix. Many extract companies already employ the reintroduction of terpenes for flavor, etc. There are also extract companies that only sell terpenes and most terpene profiles are available so one could replicate it fairly accurately.

I'm not currently aware of any simpler methods. Without using the process of fractional distillation, I don't know how you could separate the two. If you don't have access to advanced closed loop systems, you can refine an alcohol or butane extraction through a simplified process of winterization. basically using 95% food grade ethanol for extraction, you can then chill the solution in the freezer causing the lipids to solidify and clump up, then filter it through a coffee filter, then gently remove the alcohol. I think most of the common extraction processes will lose many of the highly volatile terpenes during the purge process as they typically employ heat and vacuum.

You would be on to something if you can achieve your goal though.

Thank you for that method with the ethanol. My final product would anyways be a ethanolic extract so it doesn't matter that the material is solved in ethanol and that would also contain the terpenes. Thanks a lot :)
 
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