Vacuum Oven exhaust residual gas analyzer

[JColtrane]

wow, i bit more bubbly than I would've thought ....

 

[Gray Wolf]

wow, i bit more bubbly than I would've thought ....

An unwinterized subzero extraction using liquid N2 for coolant.

A new purging process, that Joe discovered by falling asleep and waking up the next morning to find this in his oven.

So hard and brittle at room temperature that it difficult to break off a piece without it breaking into smaller fragments.

Now to see how reliably he can reproduce it, given that it was seemingly made by the elves as he slept.

 

[gholladay]

This is an exciting thread! How cool to get to use a mass spec and finally get some hard evidence for what's going down in the vac oven! Can't wait to learn more about the results. Thank you GW and joe!

 

[A6 Grower]

I love when I wake up to find the elves did all the work for me. If I pour out liquid onto ptfe and have a thin film that's thinner then paper I can get a > 50ppms butane result in about 36 hours with a 90g slab on a 1.9cu across stainless steel shelf. 1 flip also

 

[cyphaman]

^^for sure...all about surface area.

 

[icmagaccount]

Made an account a few weeks ago here, I said he was utilizing the info here for flipping more and also the heated shelves on the big oven he has really helps which he also confirmed. Cascade Botanical wrote an article about heat transfer to the slabs which is also a really good read, heated shelves are the way to go because otherwise you're relying on worse forms of heat transfer and slower conduction rates. Also I've seen Dope Cooks post a few times here I'd still like him to clear it up a little more, how many flips over what surface area with how much weight in extract at what shelf temp? Obviously strain related variables exist but cannot be easily measured.

 

[icmagaccount]

^^^^

Aright I figured this may never get to GrayWolf and since he deserves to know, (may already) Ill shed some light for those not up in Instagram yet.

DopeCooks a big oil processor out of Seattle I think, went from 96 hr purge time to 48 hours. He posted RST results from Analytical360 showing 60ppm 40ppm and 40ppm total residual (keep in mind ONLY BUTANE , no pentane, isopentane, isobutane, propane etc and he uses EcoGreen butane recommended by none other than ....GW himself)

So he says 'trying some new things' 'cut my purge time down to two days, hint: its nothing to do with temperature', I guessed surface area and was wrong, and then AllDankNugRuns mentioned this thread and how he thought this might be what DC was up to....Sure enough he was right.

Dopecooks confirmed this himself, so maybe this is old news im not sure but I thought if you didnt know already that this might brighten your day a bit. I also added that not only is he cutting his purge time down drastically, but hes also maximizing terps!

Cant say enough for what your knowledge and research does for this community

 

[Rickys bong]

GW, I've used an RGA in the past on high vacuum stuff but they operate below a certain (very low) pressure.
Was the RGA directly in the pump line from your oven or did you meter some of the flow from the oven through a metering valve so the analyzer head could remain in a high vacuum environment?

Thx.

 

[SouthernOregonM]

GW, I've used an RGA in the past on high vacuum stuff but they operate below a certain (very low) pressure.
Was the RGA directly in the pump line from your oven or did you meter some of the flow from the oven through a metering valve so the analyzer head could remain in a high vacuum environment?

Thx.

I was thinking about this as well.. Engineer I am talking to claims at our working pressure its hard to analyze these outputs without fluctuation in the readings.

 

[Gray Wolf]

GW, I've used an RGA in the past on high vacuum stuff but they operate below a certain (very low) pressure.
Was the RGA directly in the pump line from your oven or did you meter some of the flow from the oven through a metering valve so the analyzer head could remain in a high vacuum environment?

Thx.

It has a separate pump that pulls a sample from the same exhaust stream as the evacuation pump, at a tee in the back of the oven.

 

[gholladay]

It has a separate pump that pulls a sample from the same exhaust stream as the evacuation pump, at a tee in the back of the oven.

That's awesome!!

 

[Chonkski]

On this subject,

Were you able to note any amounts of cannabinoids being boiled off?

It would be interesting to know what kind of differences people who leave thier pumps running have compared to those of us who stay under 29.5.

 

[Gray Wolf]

On this subject,

Were you able to note any amounts of cannabinoids being boiled off?

It would be interesting to know what kind of differences people who leave thier pumps running have compared to those of us who stay under 29.5.

No diterpenes noted, but we will soon be checking with even more sensitive instrumentation.

We leave our pump running, but keep the levels at 29.5" Hg by bleeding in dry nitrogen.

 

[Chonkski]

Looking forward to it!

A lot of people including the ever so famous Bret Maverick don't bleed in anything and just keep their pumps running for hours on end before shutting off and locking at low temps like 85°-95° Throughout several days of flipping, and claim it to be crazy that we could be boiling off THC or other things we should be mindful of.

It's always something in the back of my mind when operating the ovens...

 

[Gray Wolf]

Looking forward to it!

A lot of people including the ever so famous Bret Maverick don't bleed in anything and just keep their pumps running for hours on end before shutting off and locking at low temps like 85°-95° Throughout several days of flipping, and claim it to be crazy that we could be boiling off THC or other things we should be mindful of.

It's always something in the back of my mind when operating the ovens...

Theories abound, including my own, and most folks just pump to full vacuum, but a check of the boiling point of THC at the different vacuum levels, suggests it is an issue.

 

[Chonkski]

Theories abound, including my own, and most folks just pump to full vacuum, but a check of the boiling point of THC at the different vacuum levels, suggests it is an issue.

Couldn't agree more GW!

 

[G.O. Joe]

That chart is not true because as I've posted many times, the McPartland and Russo numbers (the starting point) are under vacuum, without regard to whether they say so or not or whether you believe it. So - their charts, which many here have much more faith in than the Bible, may in fact contain flaws - I don't see any such admission forthcoming from the faithful. Published boiling points for cannabinoids are given at at least 1 mm, and are usually under 100 microns. There are dozens of peer-reviewed chemistry articles and books and references like the Merck Index to back that up. There are experimental difficulties in measuring boiling points and pressure at pressure that low, so there's a range of temperatures given that don't match up well and precise numbers are not very authoritative, compared to boiling points without vacuum.

"cannabinoids generally boil within the same temperature range (ca. 155C 0.05 mm)"
- R. Mechoulam
Handbook of Experimental Pharmacology, volume 55

 

[Gray Wolf]

That chart is not true because as I've posted many times, the McPartland and Russo numbers (the starting point) are under vacuum, without regard to whether they say so or not or whether you believe it. So - their charts, which many here have much more faith in than the Bible, may in fact contain flaws - I don't see any such admission forthcoming from the faithful. Published boiling points for cannabinoids are given at at least 1 mm, and are usually under 100 microns. There are dozens of peer-reviewed chemistry articles and books and references like the Merck Index to back that up. There are experimental difficulties in measuring boiling points and pressure at pressure that low, so there's a range of temperatures given that don't match up well and precise numbers are not very authoritative, compared to boiling points without vacuum.

"cannabinoids generally boil within the same temperature range (ca. 155C 0.05 mm)"
- R. Mechoulam
Handbook of Experimental Pharmacology, volume 55

I was unaware of the controversy, don't own volume 55 of the experimental pharma handbook, and don't see bp under vacuum in my 14th addition Merk Index, but appreciate you bringing the issue to light.

I passed it on to Kate, our Pharm D, and see if she has any insight or information. More later.

 

[Chonkski]

I was unaware of the controversy, don't own volume 55 of the experimental pharma handbook, and don't see bp under vacuum in my 14th addition Merk Index, but appreciate you bringing the issue to light.

I passed it on to Kate, our Pharm D, and see if she has any insight or information. More later.

Thankyou GW & G.O., this exactly what I was trying to stir up by asking. I know several experienced extractors who view this completely opposite from the last.

This is one of the things I'd really like to improve my tech on. I experiment and gain experience everyday with temp/pressure. But I am just one guy with no crew, so I have no one to bounce back and forth with about it, lol

 

[SkyHighLer]

That chart is not true because as I've posted many times, the McPartland and Russo numbers (the starting point) are under vacuum, without regard to whether they say so or not or whether you believe it. So - their charts, which many here have much more faith in than the Bible, may in fact contain flaws - I don't see any such admission forthcoming from the faithful. Published boiling points for cannabinoids are given at at least 1 mm, and are usually under 100 microns. There are dozens of peer-reviewed chemistry articles and books and references like the Merck Index to back that up. There are experimental difficulties in measuring boiling points and pressure at pressure that low, so there's a range of temperatures given that don't match up well and precise numbers are not very authoritative, compared to boiling points without vacuum.

"cannabinoids generally boil within the same temperature range (ca. 155C 0.05 mm)"
- R. Mechoulam
Handbook of Experimental Pharmacology, volume 55

I was unaware of the controversy, don't own volume 55 of the experimental pharma handbook, and don't see bp under vacuum in my 14th addition Merk Index, but appreciate you bringing the issue to light.

I passed it on to Kate, our Pharm D, and see if she has any insight or information. More later.

Good! I've been waiting since 3/6/'13 for some triangulated feedback on the calculated boiling points under vacuum. G.O. Joe's been on my case about it for at least six months...

But, even if the boiling points are way off, I still feel -29.5" Hg is a good depth to limit your vacuum to avoid excessive loss of goodies.