Reading the anti-emulsion teks, it is clear that salt (sans iodine, and sans flouride in countries where flouridated salt is common) is used to break emulsions by making the polar layer more polar.

My question is:

Is there any reason why people shouldn't just add salt to their extractions, even when emulsion isn't a big problem?

Seems that making the polar layer more polar would only be a good thing. NO?

It should actually increase the precipitation of alkaloids into the NP layer regarldess of other issues. At least with my limited knowledge of the subject, I can't see why it wouldn't.

Perhaps one or more of our esteemed chem colleagues could give their 2c on this issue.

What do you mean, making it (the whole aqueous layer?) more polar? You will raise the activity, ionic strength and osmolarity, but water is already a polar solvent. Perhaps you're thinking of increasing the ability to conduct electricity? On the other hand, if you dump a bunch of say NaCl into your aqueous layer and then use hydrochloric acid, I think you will actually decrease your target molecule(s)' solubility. It is certainly true for simple salts; i.e., stannic chloride is slightly less soluble in salt water because of the already-high chloride level. (Note that I chose tin because it is not ridiculously soluble like the double threat of a group I metal and a halogen, as in NaCl.) This is intuitive, but it is also a matter of thermodynamics.

If it works the same for alkaloid conjugate pairs, then you might run the risk of precipitating your product out into two layers it can't dissolve in if it's solubility as the N+Cl- salt is not that great. Anyway, if you get tap water, chances are the hardness (expressed in terms of CaCO3 and MgCO3, typically) is relatively high, so you already will have quite a lot of polar salts (among other things) in there, though carbonates are going to be less polar than their chloride counterparts. The only salt I've ever added to an separation--and this is only after the actual separation, mind you--is sodium sulfate to dry the hydrocarbon partition. If you really need a good defoaming/anti-emulsion agent, try adding a couple of drops of HPLC-grade octanol (note that I have not tried this with plant fats, but I don't know why it wouldn't work), although you might need a good rotary vap to actually get the little bit of octanol to evaporate.

The thread title is misleading. You call the addition of salt to the extraction solution to prevent emulsions as "salting". In extraction language, salting has a completely different meaning, which is basically the addition of an acidic solution to your non-polar solvent that contains your alkaloids in freebase form. This will turn them into a salt form and make them migrate to the polar layer (for example vinegar or FASW), or it will make the salt precipitate straight away from limo/xylene if its FASI/FASA. Please avoid using the terms innacurately to avoid confusion.

AlliDoIsSWIM, I think the OP meant the first supposition you had: to raise ionic strenght and help the separation, preventing/breaking emulsions in the mixture of a basic acqueous layer and the non-polar layer. In that case, its irrelevant if the water you are dealing with is hard or if the addition of NaCl diminishes the solubility of a salt alkaloid in the solution because it is freebase alkaloids and we anyways are migrating them away from water, to the non-polar.

And yeah you can add salt to the basic solution in every extraction if you want, hyperspace fool. But if you dont shake or if the pH isnt too low, emulsions should anyways be very little or settle easily, so people dont care to use more of something (even if its easy/cheap) if its not necessary.

Also, vibrations are great for clearing emulsions, and all the rest the FAQ says

Hmmmm...

1st off, thanks for that.

2ndly, I think I might be more confused now than I was to begin with. Heheheh.

I guess I should be more specific. As you must clearly know, the layer the SWIMs are trying to make more polar is not just water, but typically highly basified with lye or whatever and often containing a good amount of vinegar or lemon juice as well as whatever plant materials have managed to migrate in. Whether people use tap water or distilled water to begin with seems to have relatively little effect on the end results, though no one has really done a study on it. Perhaps you could enlighten us on the pros and cons of that burning question.

It is the grand wish of most SWIMs that most or all of the minerals and crap that are in the jet black solution stay there and only the lovely divine spice makes its way into the non-polar solvent. Obviously this isn't the case, but let me see if I understand you. You seem to be saying that the whole salting to get rid of the emulsion idea (there are whole teks on it) is probably useless, and thus the salting of the solution when no serious emulsion problem even exists would be foolish.

Does NaCl when dissolved in the polar layer add any molecular trouble-makers to the soup that might actually make their way into the solvent? (or heaven forbid... the spice itself)

While we're at it, maybe you could share some other tidbits of golden chem knowledge that might help us noob alchemists achieve the philosopher's stones. I doubt that most of the SWIMs here will have access to rare chemicals, and at at the risk of sounding very ignorant where might one even find sodium sulfate? By drying the hydrocarbon partition, what do you mean in layman's terms?

Thank you for stopping by and injecting some needed knowledge. People like you are worth their weight in coltan.

No Hyperspace Fool dont get confused. Add a salt to break emulsions, it helps a lot and definitely does not dissolve in the non polar solvent.

Ooo, oeuf. Sorry about that, I've got the limonene double A/B on my mind.

Edit: And when I mentioned the sodium sulfate, it was used in a non-spice related process where I actually wanted a dry nonpolar layer. I should've specified.

Thanks Endlessness.

Forgive me for the misleading title. SWIM having never really tried turning the freebase spice to salt, we were unaware. Perhaps the title can be edited?

Are you saying that adding salt might actually increase yeilds then?

SWIM never had emulsion that couldn't be cured by a bit more base, a warm bath, or another half hour of waiting.

Yields shouldnt really be affected in a very significant way (except for the fact that now you can get all the solvent separated), salt serves for breaking up emulsion, thats all.

If you edit your first post and change the subject, it changes the thread title

Done. If you have a better title suggestion I'm all ears.

[oops about the title edit... it is fixed]

Instead of "adding salting", just "adding salt" . Thanks