how long to purge under vacuum?

[SkyHighLer]

https://www.icmag.com/ic/showpost.php?p=5869346&postcount=75

You'd think someone would have determined the actual Bp's under vacuum, and shared by now... but we still don't have actual data on THC's Bp's under vacuum posted up.

Check out the commonly agreed to Bp at Wikipedia, and where it comes from.

https://en.wikipedia.org/wiki/Tetrahydrocannabinol

https://en.wikipedia.org/wiki/Tetrahydrocannabinol#cite_note-7

 

[Gray Wolf]

https://www.icmag.com/ic/showpost.php?p=5869346&postcount=75

You'd think someone would have determined the actual Bp's under vacuum, and shared by now... but we still don't have actual data on THC's Bp's under vacuum posted up.

Check out the commonly agreed to Bp at Wikipedia, and where it comes from.

https://en.wikipedia.org/wiki/Tetrahydrocannabinol

https://en.wikipedia.org/wiki/Tetrahydrocannabinol#cite_note-7

My 14th edition Merck Index shows the boiling point of THC as 200C @ 0.02. I read that as 15200 microns.

Since that is also about where it starts coming over using a short path, I infer it is pretty close.

 

[Gooner78]

So GW are you suggesting 29.5hg would be too high and pulling to 14,000 microns would be more suitable for maximum retention of thc??

 

[TerpChild]

So wikipedia is wrong at thc bp 157F and merck is correct at 200F based on your observations of the short path distiller?

 

[Gray Wolf]

So wikipedia is wrong at thc bp 157F and merck is correct at 200F based on your observations of the short path distiller?

200 Centigrade/392F under about 15200 microns, which is around -29.32" Hg.

We typically pull lower than that, but the mono and sesquiterpenes finish around 200C and the diterpenoids start to come across around there.

 

[G.O. Joe]

Found this online but it doesnt list boiling points under vacuum. Anyone know of a chart that has terpene boiling points under high vac?

The very first line is a vacuum temperature. So first you may want correct data to start out with. Then a nomograph calculator if nothing else. Or a nomograph - maybe the one on page 176.

You'd think someone would have determined the actual Bp's under vacuum, and shared by now... but we still don't have actual data on THC's Bp's under vacuum posted up.

My 14th edition Merck Index shows the boiling point of THC as 200C @ 0.02. I read that as 15200 microns.

I read it as 20 microns.

It's still most likely only the measurement of bath temperature and the pressure at the pump. This is the assumption to roll with until at least the actual paper those values came from is read. The line between some volatilizing and some superheating must get blurry at these pressures. Evaporator pressures are rarely given.

Going the other way on the nomograph, the 285/80 value for CBN - the first for a cannabinoid and 68 years before the word cannabinoid - is probably more accurate for conversion to atmospheric pressure value (it's less than 420) than the sub-mm. values for cannabinoids in the literature. Even if measured perfectly, under much vacuum it's still an imperfect value only worth so much. Nothing says Your Results May Vary louder or more often than organic chemistry. There's no grail number no matter how much you want one or try to find by experiment, and quotes from Mechoulam will be safest.

 

[Gray Wolf]

I read it as 20 microns.

It's still most likely only the measurement of bath temperature and the pressure at the pump. This is the assumption to roll with until at least the actual paper those values came from is read. The line between some volatilizing and some superheating must get blurry at these pressures. Evaporator pressures are rarely given.

20 microns would make more sense compared to my observations around 50 microns, but might you share how you get from 0.02 to 20 microns???

I ASSumed 0.02 atmospheres and simply multiplied 760,000 microns X 0.02............

I'm pretty sure you are right about the bath temperature, vis a vis solution, and the vacuum sensor will typically be somewhere in the vacuum plumbing, rather than in the boiling chamber itself.

I also agree that since sensor location, quality, and calibration vary considerably, process parameters aren't universal, and are order of magnitude only.

At ~<50 microns "observable" monoterpene action starts somewhere around 180C and is complete by around 200C. The next fraction is done by around 240C.

I say observable, because it's constituents vaporize off at non visible rates at other temperatures and pressures.

 

[SkyHighLer]

The very first line is a vacuum temperature. So first you may want correct data to start out with. Then a nomograph calculator if nothing else. Or a nomograph - maybe the one on page 176.





I read it as 20 microns.

It's still most likely only the measurement of bath temperature and the pressure at the pump. This is the assumption to roll with until at least the actual paper those values came from is read. The line between some volatilizing and some superheating must get blurry at these pressures. Evaporator pressures are rarely given.

Going the other way on the nomograph, the 285/80 value for CBN - the first for a cannabinoid and 68 years before the word cannabinoid - is probably more accurate for conversion to atmospheric pressure value (it's less than 420) than the sub-mm. values for cannabinoids in the literature. Even if measured perfectly, under much vacuum it's still an imperfect value only worth so much. Nothing says Your Results May Vary louder or more often than organic chemistry. There's no grail number no matter how much you want one or try to find by experiment, and quotes from Mechoulam will be safest.

Follow all the links, and download the book the first link takes you to, James W. Zubrick-The Organic Chem Lab Survival Manual_ A Student's Guide to Techniques-Wiley (2012).pdf




Btw, .01 Torr = the 10 micron level, .02 Torr = the 20 micron level.

http://www.engineeringtoolbox.com/vacuum-converter-d_460.html

 

[TerpChild]

My phone wont open the torrent file for the book. Maybe i can try on my laptop. Do i need to convert it or something?

 

[G.O. Joe]

All bp pressures in Merck are mmHg. The entry before tetrahydrocannabinols - tetraglyme - has a bp760 value, and a bp2. Tetrahydrofuran after has a bp760 and a bp176. Such notation is standard, but a disturbing trend in chemistry is exclusive use of the pascal in many publications.

So wikipedia is wrong at thc bp 157F and merck is correct at 200F based on your observations of the short path distiller?

The 157 temperature for THC is originally from what is credited as the first isolation of THC. Nothing is said there about how the number was obtained - but it shouldn't be from the bath if it doesn't say so and it's not a nice round number.

The pressure was given in that letter to the editor also cited by the Index: b.p. 155-157' (0.05 mm.) The evaporator pressure was probably much higher than that - it's more likely a pressure close to the pump even though Gaoni and Mechoulam don't say so.

My phone wont open the torrent file for the book. Maybe i can try on my laptop. Do i need to convert it or something?

You don't need this it's just tossed out there. It's no different than any other 3-column nomograph you can find somewhere else - this one happens to come with the sort of book that some people at the site should read, and it's not related to this thread except for the nomograph. Perhaps if you had a torrent application installed, torrents would work on the phone? Have you tried the big blue underlined word DOWNLOAD?

 

[TerpChild]

i found this thread on tokecity made by Skyhighler that investigates terpene boiling points under vaccuum:
http://www.tokecity.com/forums/showthread.php?43587-Vac-Pump-Discussion-Thread&p=1294580#post1294580

Its pretty cool and looks like he did alot of work at some point.

 

[TerpChild]

http://www.tokecity.com/forums/showthread.php?43587-Vac-Pump-Discussion-Thread&p=1294580#post1294580

 

[SkyHighLer]

^^ Please apologize to G.O. Joe, he's correct, and you're misreading the drift of the conversation. We've discussed this here at ICMAG Forums previously, you're getting the rehashed version, thanks for the respect.

 

[TerpChild]

Ok im sorry Joe.

I dont understand why he had to be rude to me regarding the torrent question. No one is forcing him to read or answer these forum posts.

 

[TerpChild]

Obviously if i was an organic chemist i would not need to ask questions like these in forums. Im just trying to get better at extracting, not get talked to like an idiot.

 

[redlaser]

Good luck finding someone else with the knowledge, background and experience as Joe, Terpchild.
No one is insulting you and you are living up to your name.

 

[TerpChild]

Laser, i already apologized for my immature remark. Have a nice day everyone.

 

[Gray Wolf]

A thick skin and protocol increases the probability of harmony, even though ostensibly we are all here to exchange information on this two way street forum.

Insults and appropriate reactions are in the hands of the perceiver, but we mold our perception of others by their actions, such as the use of capitals suggesting YELLING at our ostensible stupidity.

As it has unfortunately worked out with human evolution, those among us most trained and highly focused in their specific areas of expertise, are often as a result of that intense focus, relatively unfocused and insensitive to other areas, such as inter personal relationships.

As a technocrat, I fall into that category and of course everything is a matter of degrees on a continuum, vis a vis a yes or no measures so like all but two of us brothers and sisters, the mathematical odds are that I'm not the best or worst, nor are they on this forum, but at times it does get challenging on both sides of a conversation here.

Having also been on both sides of that conversation, the best solution that I've found is to be an example of what you ask from others.

Sometimes you do have to stand up to bullies, lest they grow even more insensitive and bold, but the other 99%, if the conversation is kept to a debate of scientific facts versus personal attacks, things go ever so much smoother.

Also keeping in mind that not only does the wise man learn more from the fool, than the fool from the wise man, but that the fish trap exists only for the fish.

Design your trap for the fish that you are trying to catch?

 

[prune]

IF Terpchild could read that whole passage, I believe his head would explode. lol

 

[Old Gold]

^ still missing the point, guyzzz

"As it has unfortunately worked out with human evolution, those among us most trained and highly focused in their specific areas of expertise, are often as a result of that intense focus, relatively unfocused and insensitive to other areas, such as inter personal relationships"

Hey, at least GW understands my dismissive behavior, right...