Oh well, even that happens sometimes, thanks ;-)

You too are right of course in thinking counter-current or related principles; I had been toying with the idea of a Soxhlet extractor (which, for the benefit of non-chemist kibitzers, is an ingenious 19th century device for soaking the stuff you want separated in a solvent that works on only some of the components - like just one component for example! - and then siphons it off. then the solvent gets evaporated and sent back to get more. Really neat, no moving parts, and in many labs you could see banks of Soxhlets merrily bubbling and slurping away for days on end.) Why the "h", in particular in that postion? Sorry, I haven't checked; unless it happens to be because Soxhlet flourished in Brno; you never can tell with Czechs, even certified.

Anyway, in principle something of the type could work, bit by bit, though I doubt it would actually be practical unless the stuff were really finely ground.

Hmm. Suppose the mix consisted of really dry crystals of fair size, but you then really gently applied grinding forces to break the weaker sugar xrystals and did some winnowing or sifting? Hmmm? Oh well, maybe not!

Back to the ion exchange, I guess.

Cheers,

Jon