SWIM is in the process of preparing a batch of spice from MHRB. He boiled this a number of times in water acidified with citric acid to produce a fairly huge amount on liquid. He reduced this to about a quarter by rapid boiling to make a workable quantity.

Upon basification with caustic soda the solution, which was clear dark red, turned a very thick consistency white. Keeping everything at around 40°C SWIM added non polar solvent. However unlike in previous preparations (where not so much acid boiling had taken place) the solvent layer separated to the top with a thick gelatenous gunk within the layer but not dissolved in the solvent. The only way to get this out was with a ladle and then remove the accidently transferred red soup from underneath.

SWIM will continue to repeat this stage with non polar solvent a number of times more and then go for acidification of all the resultant gunk before performing a final basification and extraction. However he is concerned that maybe something has gone wrong in the process and maybe he will get a low or zero yield.

Any assistance with what has happened and how it can be put right gratefully received :-)

Post a picture of the gunk Hard to imagine what exactly it could be

Sure, SWIM will put a photo of the gunk trapped in the solvent layer as soon as he comes to do the next extraction - probably in a day or two.

SWIM has the feeling there's a pretty huge amount of spice in the basified liquid. Loads of white precipitate dropped out when adding the caustic soda. It's going to take quite a few pulls with solvent to retrieve it all and SWIM takes these processes really slowly over days or weeks.

You're problem is probably that you didn't filter it enough. When I don't let the solution sit for the powder to collect at the bottom for a few days... If i dont do that it will turn gluggy and thick when i basify. When i basify it turns white and then black as you keep adding more lye.

Your in a tough spot here... I would suggest seperate the container in to 2 or 3 jars and add more water... that is of course if you have enough solvent...

If you don't, well then I would suggest filter out the gunk with an old tshirt, then wash the gunk with fresh water and put the water back in the solution and pull the solution with solvent. Use gloves, be safe.

You sure it is not an emulsion ? And fathomlessness, I have not filtered out the bark before many times, this has never happened to me. You're better off posting a picture so we can see exactly what has happened.

Thanks fathomlessness. SWIM doesn't think it is a matter of not filtering enough in this case. SWIM went through multiple filtrations and finished up leaving the whole lot in a wide based pyrex dish in the fridge for several days which makes all the remaining gunk stick to the bottom so that clear red juice can be poured off.

SWIM's suspicion is that all the extra boiling he subjected it too, followed by the rapid boiling to reduce the volume, somehow extracted a whole lot of plant fats (or similar?) and although these were soluble in acidic solution they all precipitated out with basification. Some then stayed in the aqueous layer and lighter ones moved to the non polar layer according to their specific gravity. This is only SWIM's suspicion but he was wondering if anyone else had had this happen to them so he can compare notes.

Many thanks for your suggestion.

I got confused when reading, did you put your pulls in the freezer for freeze precipitation but some gunk still came through? If it is plant fats, you could do a mini A/B. Add acified water to the solvent pulls to get the DMT to go back in the acified layer and then separate that water from the solvent. Then basifiy and pull etc.

No, this was as soon as I added the non polar solvent to the basified liquid. A whole lot of the white stuff from below floated up and sat within the solvent layer. You could actually see individual droplets rise up to go into the layer above. They finally occupied nearly all of the solvent layer with just a thin layer of clear solvent on top. From this I could guess they were trying to get away from the aqueous layer (a bit like fat/oil would) but probably had a specific gravity slightly heavier than the solvent so as to occupy the lower part of it.

From your last comment it sounds like it could be an emulsion...

But white stuff ? Should be black if you added enough base. Add more base see what happens.

A photo and/or a bit more info would be helpful. Specifically, what is the pH and volume of the aqueous phase (also, colour)?.

To me, this sounds like you've got the pH into the realm of alkalinity, but not so far as to release the tannins from the bark. As such, this white "gunk" could be alkaloids coming out of solution as freebase (but which haven't been dissolved in the nps due to saturation, lack of agitation or what have you).

I've never extracted from MHRB before, but I've done experiments with various acacia barks and found that the colour change of the aqueous phase doesn't occur until a pH of about 12-13 (depending on the species), while the alkaloids will start to precipitate as low as 7-8.

Also, it's worth noting that, when reducing your acidic solution, rapid boiling is less than ideal. Instead, reduce the solution at a low/medium simmer (just evolving steam rather than a rolling boil) in order to avoid oxidising (or otherwise chemically altering) your spice.

Many thanks JustCurious and BongWizard! I think you're right about the alkalinity. I've added a bit more caustic soda and the liquid's gone blacker and I'm no longer getting the gunk in the non polar layer. My pH meter went faulty during the procedure so it's giving some weird results.

This is great!! I'll still go on to do another round of A/B to increase purity but I have the feeling this is going to give a pretty good yield in the end. This batch destined for changa which I haven't tried making before.

Yeah some cheap pH meters aren't great, and you should really calibrate them every use just to be safe Glad it worked anyway.