Gas chromatagraph question for smart people

[flylowgethigh]

I am trying to read scientific papers to see what the F is going on when I vape at different temps. Papers like this one hold clues:

https://www.cannabis-med.org/data/pdf/en_2013_01_1.pdf

Problem is I don't know what this gibberish below means. If it says they start measuring when the gas is at 60*C, and increase that temp 3*/min, does that mean the juicy stuff I want to know about at my volcano temp of 150*C which would be 90*C higher. 90*C more@3* per minute = about 30 minutes into the GC run which is 65 minutes total duration at which they are at 240*C ???

GC/FID analysis
Because of the heat applied during injection and separation, GC is not able to show the presence of acidic
cannabinoids without sample derivatization. As a result, GC reveals the total cannabinoid content (acidic +
neutral cannabinoids) after decarboxylation, only.
However, terpenes can be efficiently analyzed by GC.
Therefore, an Agilent GC 6890 series (Agilent Technologies Inc., Santa Clara, CA, USA) equipped with a
7683 autosampler and flame ionization detector (FID)
was used for the analysis of cannabis terpenes as previously described [20,21]. The instrument was equipped
with a DB5 capillary column (30 m length, 0.25 mm
internal diameter, film thickness 0.25 μm; J&W Scientific Inc., Folsom, CA, USA). The injector temperature
was 230°C, with an injection volume of 4 μL, a split
ratio of 1:120 and a carrier gas (N2) flow rate of 1.2
mL/min. The temperature gradient started at 60°C and
increased at a rate of 3°C/min until 240°C which was
held for 5 min resulting in a total run time of 65 min.
The FID temperature was set to 250°C. The GC was
controlled by Agilent GC Chemstation software version B.04.01

Cause if that is the case, then we see in figure 3B of that link what goodies are activated around 310*F (about 150*C) which is my first bag. Not very cloudy and great taste (the terps!!). Not much buzz, vapor pressure of the THC is probably low at that temp.

I do the same material at 190*C for the second bag for the THC effects, then toss the material in the AVB container.

So, am I anywhere close to this GC temp thing being associated with the time in the run?

TIA

 

[maryjane481]

You are mixing up getting high with scientific study. Find the temp that works for you and be happy.

 

[AgentPothead]

Sorry I got as far as them using NAPHTHA to prepare cannabis extract and I noped.gif out of there.

 

[ESTERCHASER]

dont blame ya....solvents are bad juju

 

[flylowgethigh]

Nope, this is good stuff. My F'in laptop has a way of somehow removing my beautiful prose while I type more, and the secret to lung and head happiness went away. But I will rebuild!!

BLUF: 160*C gets the terps and hardly any of whatever makes visible vapor. Sootheing to lungs. Actives still there. 190-210*C or higher gets the actives as well as the thicker bad compounds, but that AVB made from 160*C vaped bud still has most of the goodies and oil (butter) extraction gets most /all of the THC. They showed the need to decarb, which kills off the terps but vaped them off already so what? The short vape time won't decarb I think.

So, do a bowl at 160C and skip the expensive prescription inhaler cause the lungs feel so good. Then either save that AVB for edibles, or hit it at 200+*C to get the actives. I have posted data in the AVB thread about how much gets vaped off at the higher temp and it is about 1/2. Still some for the edibles. BTW, I am now going to bake my AVB at 250*F for 30 minutes to get as much of the THCA converted. And always now do I melt the butter in water to keep the butter from exceedng 210.

OK so an old codger could vape at 160C and make cookies with the AVB. He would get ALL of the THC that eating could provide, and have great lungs.

Whatever is in the terps around 30-35 minutes on those charts feels good in lungs. Big pharma is missing out, but not ICMag.

 

[flylowgethigh]

Sorry I got as far as them using NAPHTHA to prepare cannabis extract and I noped.gif out of there.

Just a solvent to extract with different from Etoh. Yeah, n-butane would have been more relevant. The thread is all about vapor anyways, not petro-solvent extraction.

I guess I will have to learn more about this GS stuff to answer my question. Ans: Time being analogous to temp ( at which the compound for at peak flashes off - BP).

And there is also condensation to be understood. Vape a bag at a high temp and it is harsh as hell. Let it sit and cool - which reduces the thickness of the vapor - and it smooths out.

I think a way to run the bag vapor through a bong as you draw would be nice and maybe condense the waxes, like running through magma, which I chill and get a white fallout sticking to the glass, as well as amber oil. That is too much cooling.

 

[G.O. Joe]

GC has little to do with what you're thinking of. The boiling points of the terpenes are far more relevant to your concerns. The peaks indicating compounds coming off the column and hitting the FID are not necessarily arranged by volatility or boiling point even though there is a close relationship. The oven temperature program is what was found to be needed in a particular time frame to separate the mixtures and push the individual entities off the column, which they are attracted to by molecular forces.

Sorry I got as far as them using NAPHTHA to prepare cannabis extract and I noped.gif out of there.

Unfortunate point of view. It's a very good article that's come up here before.

 

[AgentPothead]

Unfortunate point of view. It's a very good article that's come up here before.

I linked it to a buddy and he said they are probably just using the naptha as a known carrier they can compare against, so it's not like people are gonna be smoking it, it just made me really anxious at first glance. I'll give it another read, cause I respect your opinion and if you say its a good article, it's probably good.

 

[I'mback]

I am trying to read scientific papers to see what the F is going on when I vape at different temps. Papers like this one hold clues:

https://www.cannabis-med.org/data/pdf/en_2013_01_1.pdf

Problem is I don't know what this gibberish below means. If it says they start measuring when the gas is at 60*C, and increase that temp 3*/min, does that mean the juicy stuff I want to know about at my volcano temp of 150*C which would be 90*C higher. 90*C more@3* per minute = about 30 minutes into the GC run which is 65 minutes total duration at which they are at 240*C ???

GC/FID analysis
Because of the heat applied during injection and separation, GC is not able to show the presence of acidic
cannabinoids without sample derivatization. As a result, GC reveals the total cannabinoid content (acidic +
neutral cannabinoids) after decarboxylation, only.
However, terpenes can be efficiently analyzed by GC.
Therefore, an Agilent GC 6890 series (Agilent Technologies Inc., Santa Clara, CA, USA) equipped with a
7683 autosampler and flame ionization detector (FID)
was used for the analysis of cannabis terpenes as previously described [20,21]. The instrument was equipped
with a DB5 capillary column (30 m length, 0.25 mm
internal diameter, film thickness 0.25 μm; J&W Scientific Inc., Folsom, CA, USA). The injector temperature
was 230°C, with an injection volume of 4 μL, a split
ratio of 1:120 and a carrier gas (N2) flow rate of 1.2
mL/min. The temperature gradient started at 60°C and
increased at a rate of 3°C/min until 240°C which was
held for 5 min resulting in a total run time of 65 min.
The FID temperature was set to 250°C. The GC was
controlled by Agilent GC Chemstation software version B.04.01

Cause if that is the case, then we see in figure 3B of that link what goodies are activated around 310*F (about 150*C) which is my first bag. Not very cloudy and great taste (the terps!!). Not much buzz, vapor pressure of the THC is probably low at that temp.

I do the same material at 190*C for the second bag for the THC effects, then toss the material in the AVB container.

So, am I anywhere close to this GC temp thing being associated with the time in the run?

TIA

I didn't read it, based on comments to date. To answer your Q, vaping at various temperatures will vary the effects of what you are vaping. One thing vaping has over combustion, is that combustion has one temperature. Boiling points of the various terps in deg F:

• Myrcene ~ 332.6
• Pinene ~ 312
• Limonene ~ 348
• Caryophyllene ~ 266
• Linalool ~ 388
• THC ~ 314
• CBD ~ 356
• Ocimene ~ 150
• Terpinoline ~ 345
• Humulene ~ 224

You can target a specific terpene, for whatever ails you or, whatever effect you are after. It is akin to, what % of amber you have/want at harvest for the effect you seek from your plant. e.g

Gdp main terp profile is: Myrcene; Caryophyllene; and Pinene. where:

• Myrecene is sedating (332)
• Caryophyllene treats anxiety, depression and pain (312)
• Pinene is better memory, mental clarity (266).

 

[flylowgethigh]

Too bad, cause there are some informative graphs in there. Ignorance is weak, do better than listen to others. I will say that the boiling point data on wiki, which may cite, is at .02 mmHG, what I would call vapor pressure, not the boiling point at 1 ATM. 315 F there is some vapor of the THC but it is not boiling, and only 0.02 mmhg pressure in 29.92 mmgg atmospheric pressure. Hardly any. Here...

https://hightimes.com/grow/what-is-the-real-boiling-point-of-thc/

If I get my story straight I will consolidate these ramblings in a single thread. Right now I am gonna do a 315*F bag. I haven't hit the Symbacort inhaler yet this AM. Doing this has allowed me to accumulate a bunch of those inhalers cause I am not using them as fast as they come in. So much for not being able to cure COPD.

I save that 300 stuff and hit it at 380 later to get a buzz. Then it goes in the AVB container. I used to think I was wasting the material, but doing it this way all of the goodness is obtained, and what gets tossed is just plant material.

 

[I'mback]

Too bad, cause there are some informative graphs. If I get my story straight I will consolidate these ramblings in a single thread. Right now I am gonna do a 315*F bag. I haven't hit the Symbacort inhaler yet this AM. Doing this has allowed me to accumulate a bunch of those inhalers cause I am not using them as fast as they come in. So much for not being able to cure COPD.

I save that 300 stuff and hit it at 380 later to get a buzz. Then it goes in the AVB container. I used to think I was wasting the material, but doing it this way all of the goodness is obtained, and what gets tossed is just plant material.

I didn't need to see pretty pictures I have come across pretty much the same thing as you. I took notes. Why 315?

 

[flylowgethigh]

OK, I go by the highest temp until vapor starts to show. This is strain dependent, like squishing is for me, and if I err on the low side so what. I have been scattering vape material posts in various threads like butter and AVB, all as I wonder out loud what is going on.

I thought it to be interesting that the terps are what is going out at 315-320. I used to do 300 but noticed I could creep the temp up and still not get vapor. The graphs in the article I posted above show that to be the case.

Different strains will show a different terp forest than the one in the paper, as we all know. As for the vapor pressure at 0.02 mm hg - that is posted for a lot of compounds. Boiling point is defined in my soggy head as the temp when the vapor pressure is equal to the outside conditions, ie atmospheric. I posted some droppings somewhere on vapor pressure and the curves show the plots for the compounds they posted, .02mm hg and through atmospheric to pressurized to many atmospheres. We care only about the stuff below the 1 atm line.

So my point is I have hurt my lungs a lot and vaping at the low temp helps them a lot. I would like to know why, and I am sure that different kinds of terps makes a difference - ie which strain. The low temp avoids the stuff that makes me cough.

If you have a volcano try it. And also, I have stunk up some threads here about the effects of how much is put in the chamber also. By the time I have this figured out we can add an ICMag supplement to the volcano manual - which has a lot of errors (digit version).

 

[flylowgethigh]

GC has little to do with what you're thinking of. The boiling points of the terpenes are far more relevant to your concerns. The peaks indicating compounds coming off the column and hitting the FID are not necessarily arranged by volatility or boiling point even though there is a close relationship. The oven temperature program is what was found to be needed in a particular time frame to separate the mixtures and push the individual entities off the column, which they are attracted to by molecular forces.

I want oven program data!!! SO thank you Mr G.O. Joe for even taking the time to help. So, and this is just a chart I found that just happens to be lighter compounds, but it could be terps and I wish we had that data... would the terps still be releasing vapor at temps under the boiling point?

https://upload.wikimedia.org/wikipe..._chart.svg/800px-Vapor_pressure_chart.svg.png

 

[G.O. Joe]

would the terps still be releasing vapor at temps under the boiling point?

If not, there wouldn't be any pine tree air fresheners on car rear view mirrors because pine would have no odor, you wouldn't see the breath of football players in Green Bay, and ice cubes in trays wouldn't slowly disappear in frost free freezers.

 

[flylowgethigh]

Sure! And it stands to reason that compounds out further on the temp domain would also release vapors below the BP. The closer to the BP, the stronger the vapor presence. Heat material to below the BP and you still get that vapor, like was shown in those VP curves.

It would be nice if the longer chain compounds could be strained somehow so only the goodies passed through.

It is the things that make me cough (I know THC is an irritant) and condense at the higher temps I think I want to avoid. To me, 420* which is great to cook off the higher temp goodies, lets too mush thick nasties loose. So now there is a need to be condensing those either in the bag onto the walls, or in a device between the volcano and the bag. I do both and am experimenting.

 

[flylowgethigh]

I saw this chart as some avitar on another site. Does anyone have a link to the real chart?

The colors are perfect in describing my effects of the vapor with varying temps.

 

[Ringodoggie]

Here ya go...

 

[I'mback]

Better quality (resolution)

 

[flylowgethigh]

Thanks Mr. Ringodoggie! I'll take it off my sig now. That was the only way to post it.

 

[Ringodoggie]

No problem, bud. Here's a bunch of them. One or 2 were bigger and easier to read. Some are round or include terp evaporation temperatures.


https://www.google.com/search?q=can...WFVt8KHanOBlsQ_AUoAXoECA0QAw&biw=1408&bih=705






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