Rate of THC Decomposition to CBN

Greenfox recently brought CAT Scientific's Debunking the Myth of THC-CBN Conversion Intensity study at https://www.catscientific.com/decarboxylating-cannabis/ to my attention, and asked my read, as it appeared to fly in the face of conventional protocol. My study at:

https://thealchemistresource.thealchemistresource.com/p/blog-page_10.html

Because I am familiar with the author, have tested the accuracy of the CAT Scientific hot plate, and know the Phd who tested the results, instead of simply shrugging it off, I dug deeper, starting with contacting Dr Justin Fischedick and seeking his insight on the phenomenon.

Always a delight, Dr Fischedick not only provided me with his thoughts, but provided me with three different serious scientific papers on the subject, which caused me to rewrite our own decarboxylation article and to add a couple more related threads to our TAR site.

The conflict between the CAT Scientific study and conventional protocol, was the rate of THC conversion to CBN after reaching the peak of the 70% decarboxylation curve. It showed a slower drop in THC than the plunge suggested by the generally accepted graph on the subject, provided by the Journal of Chromatography in 1990 .

Graph 1


The conventional wisdom to this point is that once 70% decarboxylation is reached, that the rate the remaining THC-a is converted to THC is lower than the rate that the existing THC is converted to CBN.

That turned out to not be so, as demonstrated by this graph, which I drew using the copyrighted graph published in Isolation of D9-THC-a from hemp and analytical aspects concerning the determination of D9-THC in cannabis products, published in Forensic Science International, on line18-Aug-2004



Insert graph 2


As you can see, what this graph shows is that by the time we've reached 70% decarboxylation, 30% of the THC has already been turned to CBN and other breakdown products. The reason that THC doesn't continue to rise above about 70%, is there is no THC-a left to convert.

That still doesn't resolve the differences between the rate of THC conversion to CBN to the right of the graph, after it has peaked around 70%, shown here:

Insert graph 3



As you can see in the CAT Scientific study, the rate of THC decomposing into CBN is radically different than the plunge demonstrated in the previous graph.

The answers to that question lay in the different reports, as well as within the keen fine minds of Dr. Fishchedick.

The issue is that the tests and graphs don't represent the same test material or conditions.

The Journal of Chromatography graph represented a dab of concentrate heated in an open glass container, while the next graph was in a closed container excluding atmospheric oxygen, and the Cat Scientific study was done suspended in oil.

Dr. Fischedick relayed yet another test he had run, testing formulation stability, where they placed the THC + formula in an oven and flooded the oven with oxygen. Even in that oxygen enriched atmosphere, he said that the degradation was slower then the first two graphs above.

He also noted that many of his clients research producing CBN under various conditions and it varies for all of them until they really find an optimized process.

In addition we routinely inject THC into the inert atmosphere of a gas chromatographs at high temperatures like those shown and we don't see any degradation in that time period.


He summarized by saying that unless you're heating a couple grams of oil on a hot plot exactly like the first graph, we shouldn't expect conversion to be close to the same.

Solly! Not sure what happened with all the auto bold, and I can't see an edit option to fix it.

The graph under criticism I've probably said a few times before does not show conversion to CBN. Neither in the scientific logic sense nor actually, since there's an explanation right under the graph for anyone who bothered to read the document, which was provided here many years ago. This should not have fallen to me to point out.

G.O. Joe said:

The graph under criticism I've probably said a few times before does not show conversion to CBN. Neither in the scientific logic sense nor actually, since there's an explanation right under the graph for anyone who bothered to read the document, which was provided here many years ago. This should not have fallen to me to point out. View Image

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I submit that the right side of the curve does represent THC conversion to CBN, even if it is a decarboxylation graph.

The CBN doesn't rise proportionally, because its being broken down as well.

I have never seen this pulled off, but I've known a few to try it. None of their tests came back with CBN presence. Most of those people were doing large batches, perhaps that was the issue.

I'll be watching, been interested in this topic for awhile.

can someone put this into simple terms?

At what rate does THC turns to CBN in a sealed jar at room temperature and for how long?

I have notice that once you turn hash or flower into rosin it is almost like they stop aging or changing. At what rate would THC convert into CBN when THC when in oil form?

Thanks.

Gray Wolf said:

I submit that the right side of the curve does represent THC conversion to CBN, even if it is a decarboxylation graph.

The CBN doesn't rise proportionally, because its being broken down as well.

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Conversion to CBN is conversion to CBN, which can only be determined by finding out how much CBN there is, not by finding how much THC you don't have. None is shown. CBN is quite stable and along with CBD suffers from none of the problems of THC distillation. The text from the second graph says At higher temperature, D9-THC is oxidised to form cannabinol. As the sum of D9-THCA-A, D9-THC and cannabinol does not reach 100%, it is assumed that polymeric material is formed also. If the time of exposure to temperature is changed, temperature needs to be adjusted to maximal conversion. With the chosen time, the maximal conversion is in the same range as it is in the injector of the GC system.

Let's analyze this statement. First, the second graph is not the authority you think, at face value, because no time is ever given. Kind of an important variable? Next, just because they say some reaction occurs, does not mean that it happens instantly or quantitatively or anywhere near.

Oh duh now I see that 8 is just a different representation of the handful of experiments in 3. So 15 minutes. They didn't mention the intermediate dihydrocannabinol even though they showed it on the stacked chromatogram figure 3. That's the better representation. That's one of the few places you'll see dihydrocannabinol mentioned much less shown on HPLC, yet they don't mention THCA converting to CBNA. They mention it as impurity in their THCA but don't show a peak for it. Anyhow it's not a ton of science being done here really, once again these are only what they are. This is an analytical not production journal.

Neat as can be. Thank you much.

G.O. Joe said:

Conversion to CBN is conversion to CBN, which can only be determined by finding out how much CBN there is, not by finding how much THC you don't have. None is shown.

You will never reach 100% when the same process creating CBN from THC, is destroying CBN.

You lose 30% right off the top, reaching the apex of the curve, and then the THC level steadily drops until THC reaches zero.


CBN is quite stable and along with CBD suffers from none of the problems of THC distillation.



The text from the second graph says At higher temperature, D9-THC is oxidised to form cannabinol. As the sum of D9-THCA-A, D9-THC and cannabinol does not reach 100%, it is assumed that polymeric material is formed also.



If the time of exposure to temperature is changed, temperature needs to be adjusted to maximal conversion. With the chosen time, the maximal conversion is in the same range as it is in the injector of the GC system.

Let's analyze this statement. First, the second graph is not the authority you think, at face value, because no time is ever given. Kind of an important variable? Next, just because they say some reaction occurs, does not mean that it happens instantly or quantitatively or anywhere near.

Oh duh now I see that 8 is just a different representation of the handful of experiments in 3. So 15 minutes. They didn't mention the intermediate dihydrocannabinol even though they showed it on the stacked chromatogram figure 3. That's the better representation. That's one of the few places you'll see dihydrocannabinol mentioned much less shown on HPLC, yet they don't mention THCA converting to CBNA. They mention it as impurity in their THCA but don't show a peak for it. Anyhow it's not a ton of science being done here really, once again these are only what they are. This is an analytical not production journal.

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Define polymophic material? Poly(Multiple) morphing (changing) into something else??? Like decomposition products for instance??

You probably skipped over the part of my write up that mentioned going straight to one of the worlds leading authorities on the subject for help sorting it out, and who does believe in the studies and provided them to me. He also relayed his own experiences as an industrial consultant on the very subject.

The point of the article is Greenfox's question of why the decomposition curves don't match, and the answer is that the processes are different.

Do you find error in that conclusion?

Gray Wolf said:

Define polymophic material? Poly(Multiple) morphing (changing) into something else??? Like decomposition products for instance??

You probably skipped over the part of my write up that mentioned going straight to one of the worlds leading authorities on the subject for help sorting it out, and who does believe in the studies and provided them to me. He also relayed his own experiences as an industrial consultant on the very subject.

The point of the article is Greenfox's question of why the decomposition curves don't match, and the answer is that the processes are different.

Do you find error in that conclusion?

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The answer is the 70% figure comes with grains of salt from the start. I've had these articles for ten years and don't need an interpreter, having spoken the language for a long time.

Four (4) experiments are documented, as shown in your second graph figure 8 and my link to figure 3. Different temperatures for 15 minutes, each with half a milligram of material coating the inside of a gas tight vial. Is there plastic or unsilanized glass? They don't say, so we'll say I've found your missing THC - absorbed - if dihydrocannabinol doesn't cover it.

This 15 minutes is kind of inflexible isn't it? Maybe there would have been different results for a longer time at the lower temperature and a shorter time at the higher temperature? Obviously?

How would a large peak for CBN mean CBN is being destroyed? Plus they clearly throw in the phrase it is assumed - their assumption means jack and they would be the first to admit it. There is certainly nothing there saying it's CBN and not THC theoretically dimerizing or whatever.

No one including the authors is saying it's a definitive work that applies to anything other than what they specifically did for the purpose they did it for, so there's a bit of straw man in bringing them up at all. Did the Dr. tell you they go on to say never mind about the 70% figure unless you're analyzing hemp - did you skip over table 1? It seems that with higher D9-THCA-A concentration the decarboxylation pathway is favoured over other reaction pathways such that a higher total D9-THC can be measured than expected.

G.O. Joe said:

The answer is the 70% figure comes with grains of salt from the start. I've had these articles for ten years and don't need an interpreter, having spoken the language for a long time.

Four (4) experiments are documented, as shown in your second graph figure 8 and my link to figure 3. Different temperatures for 15 minutes, each with half a milligram of material coating the inside of a gas tight vial. Is there plastic or unsilanized glass? They don't say, so we'll say I've found your missing THC - absorbed - if dihydrocannabinol doesn't cover it.

This 15 minutes is kind of inflexible isn't it? Maybe there would have been different results for a longer time at the lower temperature and a shorter time at the higher temperature? Obviously?

How would a large peak for CBN mean CBN is being destroyed? Plus they clearly throw in the phrase it is assumed - their assumption means jack and they would be the first to admit it. There is certainly nothing there saying it's CBN and not THC theoretically dimerizing or whatever.

No one including the authors is saying it's a definitive work that applies to anything other than what they specifically did for the purpose they did it for, so there's a bit of straw man in bringing them up at all. Did the Dr. tell you they go on to say never mind about the 70% figure unless you're analyzing hemp - did you skip over table 1? It seems that with higher D9-THCA-A concentration the decarboxylation pathway is favoured over other reaction pathways such that a higher total D9-THC can be measured than expected.

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The 70% figure repeats itself over multiple studies, by multiple authors, but is not fixed, as it depends on the process.

In A Qualititative and Quantitative HPTLC Densitometry Method for the Analysis of Cannavinoids in Cannabis sativa L, Dr's Fischedick, Glas, Hazekamp, and Veerpoorte achieved 85.8% recovery, but no one I've seen is reporting 100% recovery using simple heat.

It is well established that CBN is the primary degradation product of THC, and both disappear in the studies. Where do you think they went?

Speaking of skipping over, did you skip over the question regarding the reason for my post and do you disagree that the differences are due to process and material difference?

Do you have an alternate theory to share, or is this a fire for effect?

PS: When I ran the above article by the good doctor, he had the following to say about it. "I read your article it looks good. A few grammar mistakes in the last few paragraphs"

If it defuses this debate, I am not offering the above information as the basis for production of CBN, only to explain the different rates published that THC degrades to CBN and subsequently to its polymorphic degradation bi-products.

The results indicate complete conversion of THCA-A/D9-THC. The sum of the molar concentration of THCA-A and D9-THC decreased slightly after the decarboxylation, the relative loss is given in Table 1. Figure 4 also shows the data for CBN, which is a possible oxidation product of D9-THC. In this case, heating in the dark and in the absence of oxygen (vacuum oven) did not result in any significant oxidation of D9-THC to CBN. Finally, decarboxylation studies with pure THCA-A showed clearly that D9-THC was the only decomposition product observed after heating at 110°C for 40 min.

http://online.liebertpub.com/doi/pdfplus/10.1089/can.2016.0020

SkyHighLer said:

The results indicate complete conversion of THCA-A/D9-THC. The sum of the molar concentration of THCA-A and D9-THC decreased slightly after the decarboxylation, the relative loss is given in Table 1. Figure 4 also shows the data for CBN, which is a possible oxidation product of D9-THC. In this case, heating in the dark and in the absence of oxygen (vacuum oven) did not result in any significant oxidation of D9-THC to CBN. Finally, decarboxylation studies with pure THCA-A showed clearly that D9-THC was the only decomposition product observed after heating at 110°C for 40 min.

https://online.liebertpub.com/doi/pdfplus/10.1089/can.2016.0020

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Hmm, they remark that they did it in a vacuum oven to eliminate exposure to oxygen, but don't indicate vacuum depth, nitrogen use, pump speed etc, I'm assuming they used a pump but either way, I also decarb at 145C and see minimal CBN conversion if any.

Gray Wolf said:

both disappear in the studies. Where do you think they went?

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Only if you count decarboxylating while adsorbed on chromatography silica - an acid - with or without added salts. I already made a serious suggestion. Portraying CBN as unstable and formation of polymers would be more convincing with evidence. Without evidence it's strange.

Gray Wolf said:

Speaking of skipping over, did you skip over the question regarding the reason for my post and do you disagree that the differences are due to process and material difference?

Do you have an alternate theory to share, or is this a fire for effect?

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The post was in response. You like seriously want me to give a yes or no answer as to whether I think doing something different changes outcomes? Different labs doing the same thing have different reports. It's no accident someone decided to use the name Journal of Irreproducible Results.

G.O. Joe said:

Only if you count decarboxylating while adsorbed on chromatography silica - an acid - with or without added salts.
Not true on all of the studies.

I already made a serious suggestion. Portraying CBN as unstable and formation of polymers would be more convincing with evidence. Without evidence it's strange.

You don't have the answer, yet you believe that CBN also decomposing into polymorphic substances from the same heat effects strange?

The post was in response. You like seriously want me to give a yes or no answer as to whether I think doing something different changes outcomes?

I seriously want you to acknowledge that the article answered the question correctly. You've made a major issue out of a peripheral aspect, for which you offer no solid alternative answers, while ignoring the actual purpose.

Different labs doing the same thing have different reports. It's no accident someone decided to use the name Journal of Irreproducible Results.

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No argument there, but not the subject of the article, just as the debate of what polymorphic substances are created from the decomposition of THC and CBN were not.

I do expect you to have the "correct" answers if you are going to jump in with both feet and take major exceptions to things.

Otherwise I think a simple, "I disagree that THC turns into CBN first", more than adequate and more in the spirit of this forum.

That's why I'm stress eating

In other words, what is my opinion for the record of catscientific's decarboxylation experiment, which I summarize:

Extracted without heat and presumably filtered, then heated in open-air stirred 122c coconut oil for 24 hours. Absolutely nothing about CBN decomposing. Nothing about polymers. THC to CBN conversion of 100 micrograms per ml per 6 hours.

In the text they refer to a graph and the 70% number, but the graph I get is that of your first graph - Veress et al. figure 3 - which is definitely not what any part of the text is referring to. Perhaps it can be assumed they are talking about Dussy et al. - your second graph, and the one I linked to, figures 8 and 3.

A popular reasoning behind this thought process is explained in the graph. Here, we notice after 70-percent of decarboxylation is achieved, THC levels decline at a rapid rate. In doing so, the CBN ratios simultaneously rise. Ultimately, this alters the psychoactive qualities of the extract by making it more sedative in quality.

However, throughout our own research, we’ve uncovered significantly different results.

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What Dussy's graphs show is as catscientific says, in the context of what Dussy does, but barely at 140c, slightly at 160c, and most especially 180c. Again, they heat in coconut oil at 122c. At 120c for 15 minutes Dussy shows 20's% conversion and presumably 50% remaining THCA. How to get to 100 is unclear and not even mentioned anywhere other than drawn in fig 8. Fig 3 shows no peaks other than THC and THCA at that temperature.

Like I said, straw man. You seek answers I've been giving all along.

I'm open to cannabinoid polymers especially dimers and such and weird extract condensations in general - this is easy to see with MS. But no weird molecules are suggested by any of the three, other than Dussy's over 150c it is assumed phrase - with no evidence of any kind and perhaps to obscure the fact that their experimental work didn't actually go right for them in practice with hash and could have been better in probably many ways.

Your third graph. I don't get this on catscientific's page either. They don't mention in the text THC falling from 17 to 13 in the graph. Is this mg/ml of neutral THC like it appears? They don't make any indication except that they're pleased, yet the way it's drawn suggests no less than 24% of the THC was lost. Apparently they do not suggest doing what they did.

Gray Wolf said:

Not true on all of the studies.

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Go ahead and give any paragraph, sentence, graph, or table that you think scientifically supports products other than THC, dihydrocannabinol, and CBN in these works, or anything disappearing other than THC and THCA - except under certain circumstances as in my last post.

Gray Wolf said:

You don't have the answer, yet you believe that CBN also decomposing into polymorphic substances from the same heat effects strange?

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Science is funny that way.

Gray Wolf said:

I seriously want you to acknowledge that the article answered the question correctly. You've made a major issue out of a peripheral aspect, for which you offer no solid alternative answers, while ignoring the actual purpose.

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The reason for the THC disappearing at 122c being volatilization is a peripheral aspect? I'd think you'd latch on to this since this was an early concern of yours here wasn't it.

G.O. Joe said:

In other words, what is my opinion for the record of catscientific's decarboxylation experiment, which I summarize:

Extracted without heat and presumably filtered, then heated in open-air stirred 122c coconut oil for 24 hours. Absolutely nothing about CBN decomposing. Nothing about polymers. THC to CBN conversion of 100 micrograms per ml per 6 hours.

In the text they refer to a graph and the 70% number, but the graph I get is that of your first graph - Veress et al. figure 3 - which is definitely not what any part of the text is referring to. Perhaps it can be assumed they are talking about Dussy et al. - your second graph, and the one I linked to, figures 8 and 3.

What Dussy's graphs show is as catscientific says, in the context of what Dussy does, but barely at 140c, slightly at 160c, and most especially 180c. Again, they heat in coconut oil at 122c. At 120c for 15 minutes Dussy shows 20's% conversion and presumably 50% remaining THCA. How to get to 100 is unclear and not even mentioned anywhere other than drawn in fig 8. Fig 3 shows no peaks other than THC and THCA at that temperature.

Like I said, straw man. You seek answers I've been giving all along.

I'm open to cannabinoid polymers especially dimers and such and weird extract condensations in general - this is easy to see with MS. But no weird molecules are suggested by any of the three, other than Dussy's over 150c it is assumed phrase - with no evidence of any kind and perhaps to obscure the fact that their experimental work didn't actually go right for them in practice with hash and could have been better in probably many ways.

Your third graph. I don't get this on catscientific's page either. They don't mention in the text THC falling from 17 to 13 in the graph. Is this mg/ml of neutral THC like it appears? They don't make any indication except that they're pleased, yet the way it's drawn suggests no less than 24% of the THC was lost. Apparently they do not suggest doing what they did.

Go ahead and give any paragraph, sentence, graph, or table that you think scientifically supports products other than THC, dihydrocannabinol, and CBN in these works, or anything disappearing other than THC and THCA - except under certain circumstances as in my last post.



Science is funny that way.



The reason for the THC disappearing at 122c being volatilization is a peripheral aspect? I'd think you'd latch on to this since this was an early concern of yours here wasn't it.

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Truth is shorter than fiction and the sad truth is that neither of us know for sure what all the polymorphic compounds are produced from the degradation of THC, nor did the learned doctors who did the papers.

Therefore we are both debating opinions, which I've shared mine and I believe you have adequately and loudly shared yours.

Having done so, I am no longer going to debate it with you, because fortunately pleasing you is not one of my job requirements, and I do have more productive pursuits.

If you can prove CBN is not the primary degradation product of THC, then please present that information to end this debate.

Until then, repeating yourself and saying it louder is wasting both of our times.

Bending and misrepresenting what I said is also a waste of time, IE: Our discussion on evaporation below boiling point under vacuum.