Where did my crude go? MeOH Mysteries

Alright fine people, help me regain my sanity. We are doing some methanol winterization trials and lost some mass somewhere lol. We took 150g of CO2 extracted crude (ugly high pressure stuff) and winterized 5:1 in 90% MeOH. Tared out our filter papers and vac filtered through 2um papers. Pulled about 25g of gunk. When we recovered it in the rotovap, we only pulled 69ish grams. What in the sweet fuck?

I’m trying to rule out hallucinations but what gives? We pulled out almost the full 750g of MeOH out of the receiving flask and I’m sure the rest is in the cold trap. Recovered solvent is dead clear. Mental health check please folks.

Could be from transfer losses

What size roto did you use to recover?

150g is a small amount to winterize IMO

2 Likes

How exactly did you measure the quantity of fats removed? What type of filtration are you using (apparatus, papers, powders)? Did you use excess solvent following the filtration to “wash” the filter cake?

1 Like

Recovery was in a 5l rotovap. Poured the tincture in and pulled until dry using a vac reg at 47C. After the alcohol stopped pulling we dropped it to 50 torr for about 5 minutes to pull the last of the water (plan was to keep the methanol at around 90% m/m). After that we took it off and weighed the flask directly against the recorded tare weight because yeah, getting 100g out of a rotovap flask is hell.

We ran a 4" buchner funnel with a 2 um paper and no media into an erlenmeyer flask. I weighed the papers (2 were necessary) at about exactly 1g before loading them up. After all of the solution was filtered, I ran 4 50ml washes of virgin 90% MeOH over each paper through the same setup; the wash was combined with the rest of the tincture. After the papers were washed, I pulled them off, let them air dry for a bit, and then weighed them on the same scale as they were tared on and the starting crude was weighed on.

1 Like

Water in the co2 oil?

3 Likes

Could certainly be some but not ~50%. Also the ball would have been bubbling like mad when we pulled it down to 50 torr in my experience and there would have been more material in the receiving flask. I can check the proof on it tomorrow to confirm that’s not the case.

did you decarb before filtering?

How big of a filter did you run it through

2 Likes

Decarb’d at 110C for one hour in the rotovap before diluting in methanol.

Filter was 2um qualitative paper filter. 4" buchner funnel.

and then weighed (and diluted)?

This is not gonna help you figure out what happened but why are you using 90% methanol and not 100%?

The azeotrope between ethanol and water is the only reason you would allow water in your alcohol for the use of winterizing. Methanol forms no such azeotrope so any water is just reducing your capacity to dissolve cannabinoids.

2 Likes

Perhaps, because the extraction was done at such high pressures, you pulled all your potentially soluble target compounds. Perhaps (and this is a function of your starting material) you pulled a decent fraction of terpenes and other volatile chemicals.

You started with 150g

-25g Fats = 125g
-15g Terpenes (@10% terps) = 110g

And I’m at a loss. I have no idea where the other 35% is?

Edit: Account for another 13g for decarb (110-110*0.877)

If there was residual co2 call it a few more grams, maybe 4g

Around 90ish grams is what I’m calculating for output?

2 Likes

The amount decarb’d was larger (a few hundred g). It was weighed out before diluting. This was a trial so we were pretty tight about recording our details. I will double triple check the tare on the ball is correct though.

1 Like

Water content is to adjust the alcohol polarity, aiming for a sweet spot with the dilution ratio. Also we had some data points for 90% and not as many for 100%. Lastly, the next step is heptane LLE and the water helps push the cannabinoids into the alkane layer (not that the water couldn’t have been added after winterization).

2 Likes

I wish we were pulling 10% terps lol. I guess we probably are but most of them are the nasty thick gummy ones, not the fun smelly ones. I was thinking exactly the same thing, maybe we codistilled a bunch of random crap by accident; I just don’t think the solvent would have come out clear, and the extra mass should have been in the receiving flask.

Also one more finer point, the input weight was decarb’d so that’s another 13% unaccounted for.

I’m kind of leaning with we totally fucked it with the procedure somewhere but I just want to know where lol

1 Like