My dwarves are busy with a xylene/fumaric acid extraction and have promised me a report soon.
In the mean time however, they expressed wonder on something they (the dwarves) observed:

Following the precipitation of DMT-Fumarate, it has to be washed with anhydrous acetone in order to get rid of traces of xylene AND unreacted fumaric acid, which also precipitates to a certain extend when FASA is added to xylene anyway. For curiousity's sake, they kept the combined acetone wash-waste (200 ml of it), and evapped it on an large inclined petrie dish.
The result was your typical jumble of yellowed crystal needles (fumaric-acid)at the low-point of the incline, fine yellow grains (??) on the high-point of the incline and brown waxy stuff in-between the two (oils/waxes, perhaps some DMT-oxide).

Such was observed and noted.

However, then it was time to clean the dish. Xylene first. ALL disolved except the waxy stuff, which turned to clear reddish-brown droplets floating and sinking (!) in the xylene. When decanted, the droplets remained somewhat stuck on the glass dish.
Next: acetone. The droplets hardened-out and now REALLY became stuck to the dish. They could be smeared out until the glass looked like someone wiped dirty vaseline all over it: totally opague.
Last: (warm tap)water. Gone in 60 milliseconds. Clean. Could eat from it.

Now, what is extractable with xylene, dissolves in acetone and after drying dissolves in neither but DOES dissolve in water?
Are my (bracketed) assumptions in the second paragraph utterly off?

In the absence of ideas, my own mind didn't stop working too.
I think the most likely explanation is soap. Some fats and oils may have become saponified during the basing-phase of the extraction, and got their little polar (OH) heads aligned just right for them to adhere to the Fumarate-salts. This is the only assumption; the rest of the behaviour is in line with soaps.

Well.... it's an explanation.....

how much acetone was used to dissolve it in the first place, and how much acetone was used to wash the container away? Maybe if you used more in the wash, it would dissolve?

I know its very interesting to question these things but considering it was not in the "wanted" part but rather in what you were discarding, I guess its not sooo important, right?

But anyways, its hard to say, maybe some of our chem experts would have a good guess.. The fact it dissolves in water but not in xylene/acetone shows its something very polar. You say you think it might be soaps that were formed during the basing phase but then how would this explain that it first dissolved in xylene and acetone but later it didnt in either?

There are many possibilities, maybe it was some kind of clathrate compound that prevented whatever it was from dissolving in those solvents, but that actually would normally be soluble in the xylene/acetone if it wasnt for the protective layer preventing it or smt? Or who knows...

Im waiting for the day when we all have some gc/ms kind of equipment at home to test these things

A lot of acetone to wash the Fumarate, and just bit to try to redissolve it. You're right, that could be the answer, but the way it behaved... my money is some other explanation.



True! But there's fun to be had with this kind of observations! I can classify my musings as brainfarts, but boy do they smell funny sometimes...



Yes.



Wow... had to look up clathrate And yes, something along those lines.
While probably not a clathrate in the true sense of the word, the action of soaps in a mixed polar/non-polar suspension could give rise to such an occurrence: there could be some (ionic?) mechanism that nudged the soap-molecules with their polar tails pointing outward and the drying out of it reversed or mixed them up later. Faaaaaaaarr fetched, I know. But plausable, I think.



<sighs> One day our ship'll come in.... Mister Tricorder, perhaps?