Column chromatography for honey oil

[vostro]

Does anyone have experience using column chromatography for the isolation of cannabinoids (mainly THC) in honey oil? I've researched high and low and have only been able to find mentions but nothing helpful for someone figuring it out. My basic idea was to run ground bud through a Soxhlet with hexane, purify through silica gel column chromatography and remove the hexane with a rotary evaporator. If I've understood correctly, this should yield highly potent, extremely pure honey oil. I'm not interested is isomerization.

The only problem is I don't have any experience using column chromatography for lipid extraction. Anyone who does, I'd welcome a tip or 3 sentence how-to. It would be useful for others too!

If you have no idea what I'm talking about you can look here:

Soxhlet extractor - Wikipedia, the free encyclopedia
Rotary evaporator - Wikipedia, the free encyclopedia
Column chromatography - Wikipedia, the free encyclopedia

Yeah some of the equipment is kind of expensive but I'm of the philosophy to do things right or not at all.

Thank you!

vostro Reviewed by vostro on 09-22-2007. Column chromatography for honey oil Does anyone have experience using column chromatography for the isolation of cannabinoids (mainly THC) in honey oil? I've researched high and low and have only been able to find mentions but nothing helpful for someone figuring it out. My basic idea was to run ground bud through a Soxhlet with hexane, purify through silica gel column chromatography and remove the hexane with a rotary evaporator. If I've understood correctly, this should yield highly potent, extremely pure honey oil. I'm not Rating: 5

[vostro]

I think I found the answer, for anyone interested in producing the highest-quality possible honey oil. This page and flash movie carefully explains the steps:

Column Chromatography

So the best procedure would be to:

• Run the cannabis through a Soxhlet extractor using hexane as your solvent (easier, healthier, safer, and more efficient/selective at extracting THC than butane or other alternatives).
  
• Process the result of the extraction with a rotary evaporator, sometimes called a rotovap for short.
  
• Process the result of the evaporation with column chromatography, stacking the column, from top to bottom with: sand, silica gel, sand, cotton. Add hexane to the top of the sand before you add the honey oil as a buffer. Attach a syringe to the bottom of the column to pull the oil through.
  
• Process the result of this once again through the rotovap to remove the hexane.

What you have at the end of this process should theoretically be a somewhat reduced, but extremely pure, clean, and potent honey oil.

Silica gel is kind of expensive, but you can find it at electronics stores. A bonus is that apparently it should work pretty well for curing; if you threw a packet into a mason jar with the bud it should absorb the moisture as it comes out of the bud. Much more exact than "open the lid every once in a while".

[vostro]

Here's another helpful instruction (hey both from Canada what the heck)

Sephadex Chromatography

According to some extraction methods I found people use Sephadex for the chromatography filter although regular silica gel was more common.

Apparently, this is how the government (National Institute on Drug Abuse) makes hashish when it needs it for research purposes:
SpringerLink - Journal Article

[vostro]

This guy (Robert A. Nelson) wrote some pretty solid sounding instructions roughly based off of this method also:

6.2 Extraction ~

Cannabis must be dried be it is extracted, because it is not possible to remove more than 50% of the cannabinoids from fresh material THC-Acid is difficult to extract If you plant to convert the THCA to THC, the plant material should be thoroughly decarboxylated by heating it under nitrogen at 105° C for 1 hour before performing a solvent extraction.

Chloroform is the most efficient solvent for the extraction of THC from cannabis. A single extraction will remove 98-99% of the cannabinoids within 30 minutes. A second extraction removes only 88-99% of the cannabinoids within 30 minutes. A second extraction removes 100% of the THC. Light petroleum ether (60-80°) also works well, but a single extraction removes only 88-95% of the cannabinoids; a double extraction removes up to 99%. Ethanol also can be used, but it removes ballast pigments and sugars which complicate the purification of the resin (11, 12)

Extract the dried cannabis with a suitable solvent for several hours at room temperature or by refluxing. Filter through charcoal to clarify the solution, then chill overnight to precipitate waxes, then filter the solution again. Concentrate it to one-half volume, and extract it with 2% aqueous sodium sulfate (to prevent oxidation). Separate the aqueous layer, and strip the solvent. The residue is crude hemp oil.

The odoriferous terpenes can be removed by steam or vacuum distillation. Cautious distillation in vacuo yields a fraction of crude red oil (bp 100-220° C/3 mm). This can be purified by redistillation or column chromatography. Use ethanol to remove the residue from the flask while it is still hot. Filter the solution through charcoal, and strip the solvent. Distill the residue to yield pure red oil (bp 175-195° C /2 mm). Distillation must be stopped if smoke appears, indicating decomposition. (13, 14)

Because THC is heat-sensitive, it is preferable to isolate the cannabinoids by column chromatography. The simplest method of column chromatography is performed with ethanol and ether extracts of hemp on alumina, yielding two major fractions: (1) chlorophyll, CBD, and CBN, and (2) THC. A second, more difficult method is performed on Florisil (use 10 times the weight of the oil) with the solvent system hexane:2% methanol. This yields a doubly-concentrated, viscous oil which can be repeatedly chromatographed on alumina to separate the THC and CBD. (15)

[Coelho]

I was going to post the link to the Robert A. Nelson page... but you already found it. :clap::thumbsup:

[coledog855]

You might want to use a "C-18 Sep PaK", because it's nonpolar and will retain the THC, then you could run something like toluene or something even less polar through, but you'd have to then precipitate out the THC, which I really wouldn't know how to do.

Supplies to do this wouldn't be that much. A plastic syringe, polar or nonpolar column, plastic tubing,

[vostro]

Well hexane and chloroform are both extremely nonpolar, is there an advantage over those?

I've seen in the best quality instructions I could find TsOH being used for isomerization.

The expense I was referring to was for the rotovap and Soxhlet extractor. The column chromatrgraphy setup doesn't look *that* cheap, but the cheapest of the set. If I found it all used I think I'm lookin at $800 minimum. I think it's worth it though. I don't like working with crude home-setup approximations when you're dealing with chemistry - especially when the product is going into your body.

Do you have any experience using any of this equipment or procedures for the purpose of making honey oil?

[coledog855]

Well hexane and chloroform are both extremely nonpolar, is there an advantage over those?

If I were you, I'd look up the polarizability for a bunch of differnt common liquids and use one that pretty close to what THC is or less.

I've seen in the best quality instructions I could find TsOH being used for isomerization.

The expense I was referring to was for the rotovap and Soxhlet extractor. The column chromatrgraphy setup doesn't look *that* cheap, but the cheapest of the set. If I found it all used I think I'm lookin at $800 minimum. I think it's worth it though. I don't like working with crude home-setup approximations when you're dealing with chemistry - especially when the product is going into your body.

Wow! Idea it would be that expensive. If you can, look around to find a cheap nonpolar column. I've used them in labs before, and they didn't seem that high tech.

Do you have any experience using any of this equipment or procedures for the purpose of making honey oil?

Not for honey oil, but this thread def has me thinking about ways to extract pure THC off the buds. I'm thinking that maybe you could do something like this, but you'd draw the THC out of cannabutter.

[vostro]

The butter base would be good because all the THCA would be thoroughly decarboxylized which is a requirement for efficient extraction.

That chemist said that chloroform extracts 98% of THC on its first pass. It sounds like that number is coming from somewhere, and it sounds like he knows what he's talking about so I'd go with that.

If you ran dried, ground bud through a Soxhlet extractor with a solvent that targeted 98% of the THC, then through a rotovap, then through column chromatography and rotovapped it again you'd have something pretty damn close to pure THC.

The next step after that would be isomerization, which involves a separatory funnel and tosic acid. It sounds kind of like a pain in the ass for the volume of product that you get. According to one guys experiments the result is a product so pure that you could dip your finger in it, lick it and be stoned. Isomerization also, apparently, creates a high that is much different from smoking THC along with the other cannabinoids. That's why I'm not interested in it.

Chemically pure THC is a transparent oil and gets even more complicated to produce than what you go through with isomerization, though that's a precursor. This guy explains it pretty well:

Amazon.com: Cannabis Alchemy: Art of Modern Hashmaking: Books: Gold

If you don't have access to a lab though it sounds like the setup would be pretty expensive.

That's why my goal is just the very pure non-isomerized honey oil. It's sounds like it'd be PLENTY strong without going through all that extra effort.

[vostro]

Any advice on what is meant by this:

Concentrate it to one-half volume, and extract it with 2% aqueous sodium sulfate (to prevent oxidation). Separate the aqueous layer, and strip the solvent.

I know sodium sulfate becomes aqueous in 7 pH water - beyond that I'm lost. Isn't concentrating and stripping the solvent the same thing? Isn't stripping the solvent HOW you concentrate it? Is the sodium sulfate so that when you use heat to evaporate the solvent (65 C for chloroform) there are nucleation sites available?

Also, is this image the proper setup for an evaporation?

I went from honors bio to AP bio in HS because I was friends with the teacher, skipping the chem pre-requisite. Why? The chem teacher told every class their first day that he guaranteed everyone would fail. 95% did. Total asshole and GPA suicide