Hi there

I'm curious about the manske process when extracting Harmala alkaloids from rue.

I know there are guides on how much salt to use, and I understand that too much salt causes a premature precipitation of the alkaloids, but what if I don't use enough salt?

Salt 'pushes' the alkaloid out of solution, so less salt is less 'pushing'.
As you noted, at first that effect is noted by slower crystallization. As the salt concentration goes down further the crystallization is further slowed down and more alkaloid is left in solution at the end, reducing your yield.

Thanks Elrik. After leaving overnight at room temperature there was only a fine floaty sediment at the base of the jar.

It's now in the fridge here as ambient temps are fairly high in late summer.

Would re-heating and adding more salt help?

I was thinking of doing this to the point where I see something crash out, the dilute a little to dissolve alkaloids and then cool slowly to get crystals.

Thanks!

Hi bongoman.
Don't underestimate the importance of alk concentration in the equation. A higher concentration needs less salt, a lower concentration needs more salt to get to the same precipitation. So it depends how much salt you need. It's not a subtle difference actually.

bongoman,

I don't feel there is anything more I can add to Jees' and Elrik's responses, except perhaps some extra reading from the user who I believe popularised salt extracting.

www.dmt-nexus.me/forum/d...aspx?g=posts&t=32567

Essentially, salt 'pushes' the non-polar freebase alkaloids out of a basic solution (as Elrik stated) and should only effect yield due to decreased concentration of alkaloids in your solvent.

And as Jees stated, a higher concentration solution should precipitate your product more easily, whether freeze precipitating or evaporating the solvent - thus requiring less salt.

Edit: somehow missed your second post, but I see no harm in reheating your solution to add more salt and then freeze precipitate if possible.

Thanks everyone.

I heated up the salted solution and reduced it a bit and added another 10g salt and a couple of hours later am seeing some nice growth.



However I feel like I'm flying blind trying to estimate the optimal amount of salt for the manske steps.

Looks good bongoman

The Tao of Rue Extraction recommends 10g of salt/100mL of harmala solution, and allowing the solution to cool slowly for nice crystals. Probably not worth measuring your volume now, but for next time... There you go

Yes, 10g per 100ml of brew is essentially the minimum and 20g is the practical maximum.
I usually fall in to the 12-15 region if its not the final purification step.

One trick I learned for the initial crystallizing from seed brew is, once crystals have formed and are removed, if the salted brew is heated up hot again [without needing to reduce volume at all] and then left to cool and ultimately spend the night in the refrigerator, an extra dose or two of harmalas might crystallize out. It doesn't always work. I think the bonus dose comes from microscopic crystals that had remained suspended in the brew and didn't get settled or filtered out the first time.

Elrik, your microscopic crystal theory sounds quite plausible.

I think you're correct in that the smallest crystals will stay suspended in solution, and by heating the whole solution you're providing a chance for them to crystallise again with the larger xtals

I've also read anywhere from 10g-20g of salt, but it really does depend on your concentration of material in solution (bongoman).

It seems there's still a layer under those crystals, even after a night in the fridge.

I'm now left pondering the best way to seperate the crystals to run a few more manske steps on them. Can I simply filter what I have there?

Yes, filtering will remove your large crystals from the solution containing uncrystallised product in order to further process (I believe that's what you're asking).

There's quite a bit of goop in there as well. Maybe the next manske step will clean that up.

Yes salt is there for multiple reasons: to convert harmala salts from acetate to hydrochloride (if vinegar was used) and to lower solubility of the said hydrochlorides. Finally, it also helps separating harmala alkaloids from other stuff, like the finest particles (goop) and other alkaloids.

Sometimes I get get nice crystals with even 70 g/L salt, but 100-150 g/L is needed for initial run (there are impurities and less space for crystals to grow) and about 100 g/L for recrystallization.

This is incorrect. It is addition of base that causes the freebase to precipitate. You are confusing this with how the addition of salt helps to push non-polar freebase DMT into a non-polar solvent, such as in Cybs 'Max-Ion tek'.

Harmala hydrochlorides precipitate from an acid solution upon the addition of sodium chloride because they are the least soluble component in the system. Further insight into this can be gained by reading up on "the common-ion effect" and "solubility product". When the product of the concentration of harmala cations and chloride anions exceeds a value called the solubility product, harmala HCl will precipitate until the product of the concentrations is reduced to this value.

https://en.wikipedia.org...ibrium#Common-ion_effect