Breaking Emulsions

In the lab, there's this (oil in water) emulsion that I want to break in order to study the continuous (aqueous) phase. I am just trying to put my random ideas here.

By design, the emulsion is pretty stable, so doing simple things like washing with a solvent won't work. Because I want to study the continuous phase, I don't want to change the chemical composition of the emulsion too much either. Letting the emulsion sit will work, eventually, with the operative word being "eventually".

My first thought was distillation. In retrospect, it's pretty obviously a bad idea.

My second thought was centrifugation. Lacking a centrifuge, and lacking the resources to rig one up, this is a no go. (Too cheap to buy a drill/something that spins really fast, or I'll try it...)

From The Internet I heard that the following works:

• Freezing
• Adding a saturated NaCl solution
• Adding an alcohol (e.g. isopropanol or glycerol)

For the first one, I'll have to see if I can take some samples home and stick them in the freezer. For the other two, I am not sure how much reagent is required to break the emulsion. The reagents are cheap (always a good thing), and pretty harmless in terms of changing composition, but they will change ionic strength and/or dilute the continuous phase down for sure.

For some reason, pharmacies don't sell the 99% isopropanol much anymore. It's getting increasingly difficult to find the good stuff these days.

Reminder to self: keep the "scrap" emulsion that nobody wants and play with them.


[Edited]
Experimental results, for those who wanted to know:

• I didn't try freezing because I kept forgetting to take the sample to the freezer. Oops.
• Salting causes creaming, but it's still hard to get at the continuous phase
• Alcohol works a little *too* well - the stuff seizes up to this semi-solid mass with all the continuous phase trapped inside (and no way to get it out)

Sadly enough, letting the emulsion sit for a few days seems to work the best. Sigh.