The electrolysis idea is quite interesting, although what you're thinking about may be more akin to electrophoresis. As Du57mi73 says, it won't work in a non-polar solvent but from what you've been saying it sounds more like you'd be wanting to try it on the acidified aqueous phase anyhow.

Freebase alkaloids are of course generally electrically neutral and therefore would not be attracted to either electrode. The salted alkaloids would collect around the cathode, as they are cations. Beware of electrolytic reduction and hence possible weird dimerisations and the like, though!

I'm thinking more and more now that the magnesium sulphate trick is a genius idea. Perhaps it works with limonene too? :thinkthinkthink: