Why?
Because: enquiring minds need to know…
How do you teach an hplc to tells you what you been huffing in an “inline-ish” manner as possible?
High thought: could you fill a bong with solvent and pull vac while the vape hits? Send the “bong water” through the unit after standard work up?
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you bubble the vapor through a your mobile phase as it leaves the bottle with a mixing cell? You’d need a huge debubbler after the mixing cell to keep bubbles our of your column.
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So what you’re saying is that you’ll also be paying a human to smoke weed into a machine all day?
I would like to volunteer since I spend most days at my desk surrounded by computers and wires and shit - I feel that i’ve got the best qualifications to sit in one spot and get high here.
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btw this analysis is currently a demand from the FDA from all prospective entrants into the nicotine vape market.
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Found one lab advertising it but not the secret sauce…
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Is there a way to flash freeze the vapor so it recondences? or am I just shooting for the stars… If there was was way to use like a budzooka that didn’t use combustion in a closed environment and hooked up to the instrument
@EverettMarm after a glance, looks like they are just testing for undesired byproducts in the vapour
Fill a tube with cotton wool and condense the smoke inside then test the cotton?
sounds like this is what they did here
“A dynamic sonication-assisted solvent extraction system was developed for fast and quantitative extraction of the filter samples.”
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Assuming you need to quantify your results, I would use something like this puff analyzer
uses a syringe pump to inhale a certain ‘volume’ of vapour from a cartridge. They have their own analytics with a detector. But assuming you want to use HPLC, I would just discharge the vapour into a bubbler filled with your HPLC’s mobile phase (assuming your noids are soluble in this solvent). Then you’ve gotta do a bit of math to backtrack how many cannabinoids are in one ‘puff volume’ of the vape.
Cool project!
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You could… probably anyway… vaporize at controlled temperature through a bubbler into a liquid solution. That liquid solution could then be aliquoted automatically for injection OR further dilution and then injection on HPLC.
I imagine that the reason they are pointing to GC is because they are using headspace to control vaporization temperature and what not…and those are usually on GC. You could put them somewhere else if you wanted - take that aliquot of “air” and inject it into a liquid to run through HPLC.
Why you would want to do this, I’m not really sure. Is this really just because you don’t want the temperatures of GC? You don’t want any decarbing or other volatile destruction? If that’s the case - you could use high through put chromatography on your compound without a detector, get things really separated, and then utilize NMR or IR to do this test (IR probably cheaper…if you didn’t already have access to one).
But really - what am I missing?
There are other talking about doing this. I’ve had to pull smoke into a liquid for testing many times. Pulling vapor is similar. Doing it consistently - I mean how consistent are we asking people to do?
I used to use a vacuum pump to pull on a preroll to do a smoke test to make sure that we didn’t get any burning issues with our prerolls and infused prerolls… a simple apparatus, and it “smoked” them every time. I then pushed the smoke onto a very tiny filter (0.1 micron) that I had previously used in other lines of work to collect samples of air. They are used for industry hygiene air quality testing - so you know you are collecting everything around.
Then you extract off of that filter - using your normal process. All the materials are collected on the cellulose filter membrane.
And yeah like @PolyC says - there’s a lot of math that goes into knowing how much volume you are producing, how much you would normally lose, how much was collected, if any was lost, and then how much is coming off during the membrane extraction, and finally how accurate your identification instrument is.
Loop me in @cyclopath what are we trying to understand here and why? 
<3 I love these kinds of adventures!
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ding ding ding.
published work seems to use GC. which decarbs. which means we can’t answer @406_Chemabis’s question using published methods.
thought I had given the appropriate references to make that clear.
might require following the links and getting more context.
might be me/a neurodiversity thing 
…and yes, “blow into the jar” does seem to be the solution to getting them into solution.
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Who was the guy at the conference we went to in Long Beach with the smoking machine?
I found this:
https://chtechusa.com/products_tag_smoke_single-cigarette-CSM-SCSM.php
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pretty sure they used a GC.
This doesn’t directly answer the question, “can THCa vaporize without decarboxylating,” but it suggests that it can based on the decarboxylation efficiencies of various flower vaporizers.
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Why not just exhale into a balloon or something and collect the condensate?
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Too lossy?
Bubbling directly into solvent seems legit. Possibly a couple of different solvents just for good measure.
The puff analyzer @PolyC posted looks to use three liquid traps.
I occasionally get small amounts of THCA in my distillate… so it can vaporize without decarbing… but it’s always less than 1%.
I think I probably still need more context. There are methods to do this kind of work. Without using a GC (which is too hot…) but all of those methods still require vaporization or some other kind of combustion to get the stuff to become a vapor to be trapped as a gas. You know? So you are losing a portion.
Why are we concerned with losing the portion? What am I missing here? We could start by quartering and establish how much of an ACID there was in mols. Then we could use the GC and establish how much of each kind of substance is present (without switching away from established science) and then we could back calculate the total amount that would have been acidic to begin with.
The level of calculations needed… I mean its a lot.
I’m not sure about the other hypothesis that are given in the links because of these two items.
- Vapor/Combustion does not necessarily happen at the same rate of change and energy exchange as decarb
- You could potentially control decarb rate and therefore allow it to be carried away by other vapors (not necessarily vaporized itself…but many things are just carried along) and you might do this by modulating the pH during sample prep OR by placing it on a solid state resin during sample prep.
In either case - I’m still not sure why people are interested in the amount of THCa that might be available as a vapor.
And are we just trying to do this in a lab setting - or are we trying to do this like for science and then wanting to make a manufacturing process out of it?
I suppose that’s possible. My autism often gets in the way of understanding things that are sarcastic. Originally I thought the request was sarcastic… but then you posted about it MORE. 
And so I figured there was actually a reason that people were inquiring. And since I love these adventures, I figured I’d ask more questions about the why - and then propose some possibilities for how.
I suppose my real question is - do we actually need it to be a vapor (i.e. a gas in its gas for on the critical pathway) or do we just need it to be an aerosol (i.e. probably not a gas, but certainly able to be inhaled…) Cause those are different things. And I cannot tell what people are actually asking for.
In any case - collecting on a membrane should tell you how things are going (if you had a process for vaporizing or combusting you wanted to use). And you could also do instant IR collecting, cause you can just dab a little on the wafer and check it over and over again…depending on the wafer you could even start at X and then heat the damn thing and just keep running the same wafer over and over again.
There was a study… that indicated that an inhale of COMBUSTED cannabis included more than just THC… ah yes, this one: Chemical and physical variations of cannabis smoke from a variety of cannabis samples in New Zealand - PMC
In this study it shows that there is particulate that is inhaled during combustion activities (smoking) and that that particulate contains cannabinoids, including THC and terpinoids and such. They are, sadly, using the GCMS for their testing! However, they also use a non-GC method, but they don’t quantify the cannabinoids, because they are actually interested in terpenoids.
Looks like someone else also posted a study on vaporizer efficiency, which indicates a similar path - which is that particulate matter is inhaled at the same time, that matter may not have been fully decarbed yet.
Honestly - that makes the fact that you only absorb like 30-50% of what you are smoking make a bit more sense… because its not actually THC yet, so its not going through the same pathway that the tests are looking for.
But still - please help me understand why inquiring minds need to know. <3
You the best!
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This is where it started for me lol. My interest in pursuing the topic stemmed from my curiosity of decarboxylation temperatures of acidic cannabinoids being roughly on average 15 - 90 degrees C lower than the neutral cannabinoids boiling points. For example THCa decarbs at about 120 C and THC vaporizes at about 155 C. Any data on boiling points for acidic cannabinoids coincides with their approximate decarboxylation temperatures. So… can acidic cannabinoids vaporize without decarboxylating
@cyclopath suggested we look for any literature that looked into quantitating acidic cannabinoids in vapor (some were on aerosols), which brought a lot of interesting studies and IP.
Damn, I keep forgetting that one is chemical and other is physical, like comparing apples with oranges
In addition to the lovely selection of peer review articles, our fellow peers have been talking shop on a way to capture a THCa peak, from a vapor sample, on a chromatogram. This would suggest that acidic cannabinoids can vaporize without decarboxylating.
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