Liquid-Liquid-Extraction


#1

This months med run proceeds after a dewaxing process which left the compound dewaxed and disolved in Methanol. A 100 ml addition funnel used as a sep funnel was used. Starting crude concentrate before refinement and dewaxing was one ounce. I chose to start with 50 ml of hexane on the premise that about two milliliters hexane to one gram of extract would be enough to easily hold it in solution. My rule of thumb is one gram of extract equals about one milliliter of liquid.

On the left is the compound in a methanol solution. The sep funnel is smaller than I would like but my next size is 500 ml so I elected to do this in multiple steps in a smaller unit. Shown are the deionized water, the hexane, and the methanol used.

Here is the sep funnel loaded now with clean and pure hexane. Hexane and methanol are immiscible. Hexane and water are immiscible. Methanol and water are miscible in each other. This means that hexane will always form a layer above water or methanol. For LLE to work it does not matter if you use two, or three or more solvents so long as the compound of interest is miscible in both layers but both layers formed are not miscible in each other. I take advantage further that cannabinoid is not miscible in water and add this as a “crashing” tool of sorts for both the methanol to leave the hexane and the cannabinoid to leave the methanol.

:flushed:

My point in explaining this is that LLE has unlimited potential ways to exploit solubility and it is pretty darn cheap if your most used solvent is water and hexane budget is just two milliliters per gram of extract if you do not recover solvent. Plus I just vaped some primo oil and it’s fun explaining minute detail when savagely enjoying a good high. :man_scientist:t3:

Methanol will compete with hexane for cannabinoid until you add water. Then the water and Methanol combine preferentially excluding cannabinoid but not excluding generally the light boiling terpene fraction and other more polar compounds.

So the idea is to transfer the cannabinoid from all the methanol into the clean hexane and flush the methanol, water, and more polar compound and terps out of the mix.

Now the methanol with cannabinoid is added. You can see two layers competing for the cannabinoids. I plan a distillation so will seperate various cannabinoids there but as always interesting layers emerge. This is before the introduction of the first bit of water. Hexane layer on top and methanol layer below.

Now the water has been added and this action will cause the Methanol to seperate from nearly all cannabinoid. Look at the close up. A third layer forms at the junction of solvents that does not seem to be emulsion. It is a seperate distinct layer and I do not know why it does that precisely lolz.


Once the water runs clear the majority of the methanol has been removed. Shown here is the first bit of compound that was run through the hexane layer which provides intimate solvent/solvent contact. The catch flask on the left contains water, methanol, and terpenes/other that seperated. The clear layer in the addition funnel indicates that more Methanol and compound needs to be added into the hexane and the water wash then continues this way until all cannabinoid has been transferred from the methanol to the hexane.

Here now the last of the cannabinoid has been transferred from the methanol solution to the hexane. Shown is the amount of water and methanol collected. It started at approximately 500 ml of methanol with the compound in solution. It took a bit more than just a few liters to flush the methanol out of the hexane. Note how dark the hexane layer has become from the cannabinoids.

The white flasks will be set in the freezer. Residual cannabinoid will harden and stick to the glass. The water and methanol will become chalk white and be discarded. Residual cannabinoids will be gleaned from the catch flasks in a future lab. Likely about a quarter to a half gram or so might be recovered that way later.

The hexane is then loaded into the bottom half of the cryogenic sublimation apparatus and is allowed to evaporate in preparation for distillation.


Time lapse start to finish Sublimator run
What the Stink?!
Asahi LLE Project: Need help: Testing separations for the ECR
How much is left in your boiling flask?
#2

Sr . Beaker,
Quistion My end pruduct is Distillate .
I wan t to extract My biomass at -80C with ethanol
Now i have to by denatured ethanol
Wich would You recomend 96% ethanol denatured with 5% methanol
Or 96% ethanol with 5% isopropyl denatured
Quiestion is regards to best extraction as clean as posssible from Waxes chlorphyl etc
I like methanol but iT is more polar than iso
What would You choose ?


#3

Good question and the direct answer is I do not know which would be best. Methanol will not disolve waxes and I have a vid showing some of this but iso also disolves very little wax. Iso will not disolve plant DNA but all other alcohols will.

There is no worse or better here imo really. I tend to choose methanol if I plan to run LLE using methanol and water and hexane because methanol is not miscible in hexane but you are already going to deal with ethanol so this is moot too.

@cyclopath seems to have a good handle on this sort of thing but my hunch is it does not matter really. Many on here that actually do the commercial work will know. I use iso and methanol exrensively but I am a flaming alcoholic sober now 10+ years and my strategy that works is simply to never purchase ehtanol or be around it. Those of us with the addiction must take precautions like this.

I predict that in a decade when the world stops being hoodwinked by every health scare rumor generated by who knows, that the idea we must use some sort of so called food grade product to extract with instead of the inexpensive and safe use of isopropyl alcohol or the more expensive but easier to recover methanol (methanol does not form an azeotrope with water so can be fractionally distilled to pure) will become a dated idea. Ethanol makes no sense as a government specified product at all except that simply it is the government and when did they EVER make sense? Oregon calls CO2 a hydrocarbon! Imagine a whole state that got a high school chemistry question wrong THEN codified it into law??? It plays upon irrational and unfounded fear and only ends up adding expense and then we still have to deal with denaturing.

For not knowing the answer I can sure crank out the paragraphs eh? :nerd_face:


#4

I go for both and check for results of color green let You know the results


#5

Thats seems bad ass and im sure its effective but how do you do it safely? What ppe do you use. And what disposing procedures? polar solvents scare me.


#6

Polar solvents are water and methanol and such while a non polar solvent is hexane. My advice is to never do a procedure unless and until you satisfy for yourself of the safety of the procedure. There are myriad MSDS sheets and health and safety sheets available for use that can answer your questions about what the recomended personal protection equipment should be. From these sheets then you have to make a judgement about whether the use of that solvent is warranted from a safety standpoint and if so just what ppe you would use. It would not matter what my own standards are of ppe or anyone elses might be if the technique presents enough doubt to trigger fear because you should follow your gut when it comes to this sort of thing and simply not engage in ANY lab procedure that you are not convinced is safe enough for you.

Here is a screenshot of part of a report from the World Health Organizations treatment of Hexane, a non polar solvent. The report was written for policy makers in governments to help them ascertain basic information about a substance so they can legislate from a more knowledgeable standpoint. These are the kinds of things I look for and read through completely before deciding to try using stuff I never used before.


#7

All you really need for hexane and methanol are some nitrile gloves and some safety glasses. The MSDS always makes it seem like the chemical is much worse than it actually is. If you get some hexane are your hand, don’t worry because all it will do is dry your hands out.


#8

The worst threat to working with solvents are inhaling the vapors. That is way worse in some cases than exposure to the skin. You absolutly need ventalation in your lab.


#9

Another thing that reminds me of https://skunkpharmresearch.com/getting-the-green-and-waxes-out-afterwards/


#10

The material safety data sheet is there to tell you what you need to do to protect yourself as well as certain protocols and preventative measures to keep you safe. I wouldn’t discard safety information, especially from a safety sheet.

I was gonna order pentane but because I read the MSDS and looked into its stability and storage I decide not to. Pentane, Hexane and Heptane are the three I’m scared to use and seem like fumehood chemicals.


#12

Well to Some extent You are right with these hydrocarbons but a little directed air flow and good ventilation should keep You safe
And iT s Amazing what Tricks You can Ad to your trick box once using them