# Oil-water emulsion doesn't separate

I've steam distilled a couple of different powdered seeds/herbs to obtain the essential oils from them.

Somehow some of the extracts won't separate and stay in an emulsion.

I've seen that some fixed oils that where extracted too are separating in cool conditions, but I can't see any essential oil layer forming. Even when letting the extract (emulsion) sit for 2 weeks.

Can anyone explain why this is happening (or not) and how I could break the emulsion? Acidifying or salting it out?

Since if I would try to boil the water of off the emulsion, its vapors would carry the oils with it, so is there any way to evaporate the water but leaving the oils?

I live in a country where it's hard to obtain some chemicals, so are there any easily obtainable chemicals/solvents to use for further or better processing? I have access to $95~\%$ bio ethanol, $95~\%$ acetone, sodium hydroxide, sodium chloride and I've managed to get some naphtha.

So my possibilities are limited as you can imagine …

I've thought about using a Soxhlet extraction with ethanol or acetone where I could simply distill the extracted and concentrated solution to recover the solvent and be left with the extract (essential oil, fixed oil, etc.).

What can I then do to separate the fixed oils from the essential oils that I want?

• Hi and welcome to Chemistry. Feel free to take a tour of the site and visit the help center for any deeper questions remaining. – Jan Nov 12 '15 at 14:32
• First if you going to use the oils for some sort of human use I would NOT use acteone or naptha. (Safety in this sort of question always scares me a bit...) // Not having any idea what you're doing I can only suggest splitting the sample and trying various methods. I'd start with NaCl. NaOH might chew up some compounds that form the "oil." // 95% ethanol already is an azetrope so trying to distill with that is pointless. – MaxW Nov 12 '15 at 18:01
• Can I ask what "herbs" and what use? Or is it THAT "herb"? – MaxW Nov 12 '15 at 22:36
• First of all, no, i am not talking about mariuana plants or other psychoactive or hallucinogene plants. Some examples plant material that I've used is spices like cinamon or cloves. Or orange peels and chilis. I am not planning to consume the essential oils or use it in other forms. These experiments I'm doing are only for personal educational purpose. – Ace Nov 22 '15 at 20:15
• If my memory doesn't deceive me, en.wikipedia.org/wiki/Vacuum_distillation would be the preferred way, and if not for anything else, it would protect temperature sensitive compounds from decomposing. – Gyro Gearloose Feb 5 '16 at 21:33

## 1 Answer

I have encountered the same problem with plant extracts. I think the term is hydro/sol when the extract is suspended in aqueous solution. Anyway, I've had some success with heavy sodium chloride brine then chilling the solution to near freezing for an extended time (a week or so). Even then the return hasn't been that impressive. In most cases making a tincture (or gas)extraction then distilling the product (if you still need to) produces a much better yield.

• Brine works wonders. I would also be cognizant of your ratio of organic-to-aqueous components. I believe that oils become more soluble in water when they make up only a small fraction of the mixture. – colnegn Mar 6 '16 at 23:55