Has anyone ever used dry ice for freeze precipitation?

Some dude has access to some and it seems like a good idea for the precipitation as long as it does not cause the jars to shatter.

Any thoughts?

Thanks in advance for any serious input - - -

Sounds good to me. I might be wrong, but since CO2 is a gas and never turns into a liquid you could put dry ice in the naphtha and when the smoke clears you would have done the work of 2 days in the freezer with absolutely no contamination from the dry ice.

If you can, try it on a really small batch and see what happens???

I may have to get some if it works like I think it will. You'll end up with very fine dmt powder so don't pour it through a filter, pour off as much as you can and let drip dry.

You could also surround the jar with it, but that will take a bit longer.

Thanks for the response. I'll make the suggestion and letcha know how it goes.

SWIM has tried it and it does work nicely.

Just after few minutes in the dry ice one can see thick blobs of precipitate forming (or one can even put a chip of dry ice in the naphtha!) Then, the naphtha can be filtered to collect the precipitates.

Note however that naphtha also freezes for good at -80 C. SWIM was once fooled that he got very thick and big precipitates where in fact they were frozen solvent!

What would be a good way to prevent this from happening?

If by chance a few naphtha crystals appear would they not evaporate in the filter when sitting out to dry?

Just do not keep it on dry ice for too long... Maybe 10-20min, then take it out for some time, then stick it back in the dry ice if you may to repeat the process. It shouldn't be difficult to play around with it.

The only concern with frozen naphtha is that it will prevent further precipitation of your much wanted alkaloids. The solvent needs to be liquid at all times for the micro crystals (= precipitates) to form !

Frozen pieces of naphtha will actually thaw pretty fast and run through the filter (instead of evaporating!) They will contain some alkaloids but these won't really be big enough to be retained in the filter and will be washed through the filter along with the thawed naphtha.

Very interesting experiment. I'm assuming Noman's Tek. Or was it an Acid/Base extraction?

How badly was the yield affected by frozen naphtha pulling "The Spirit Molecule" through the filter?

For people concerned with their NPS freezing: A simple solution is to use an NPS with a lower freezing temperature than the temperature provided by dry ice (-78.5 C). The freezing point of Heptane, for example, is -90.55 C.

Naphtha, by comparison, freezes at -30 C. A typical freezer already gets you down to below -18 C, so using dry ice with naphtha isn't really going to buy you very much in terms of additional crystallization, even if you figured out a way to hold the temperature at just above naphtha’s freeze-point.

I am presently running a batch using heptane. I brought things down to temperature normally (Refrigerator -> Freezer) for a day and a half prior to moving things to an ice chest with the dry ice. I know that some people have suggested using a combo of dry ice and water ice, but this sounds like a bad plan to me. The dry ice would act as a heat-sink to the relatively warm water-ice, warming up and depleting a substantial amount of dry ice in the process. This will diminish our window for getting the NPS down to under 78.5 C and holding it there, which is the entire point.

Anyway, I’ve made sure that the dry ice is in direct content with the Pyrex dishes that I am using, ensuring good heat transfer out of the NPS. After only a few hours, the NPS is VERY cloudy again (it was getting relatively clear in the standard freezer before I moved things into the cooler), so I am hoping that some decent crystallization occurs.

I will provide an update with the results after I am finished. I may need to try things again after this first run, because with the checking that I’ve been doing, I’m probably getting sub-optimal crystal formation. I mostly want to see the size of the window that I have to work with. I don’t want to open the cooler too soon, disturbing crystal formation, but I also don’t want the dry ice to run out and the temperature to rise, allowing the NPS to reabsorb DMT. Best case scenario is to leave things completely alone, then open the cooler just as the dry ice is almost exhausted and pour off the NPS through filter-paper to catch any “snow” before the temperature rises and DMT is reabsorbed in significant amounts.

It should be noted that dry ice isn’t exactly cheap, but it’s my observation is that NPS is even more expensive (at least Heptane is), and I feel like it might be worth the cost if it results in better yields while not losing my NPS to evaporation.
Wish me luck. *crosses fingers*

Also: Full disclosure. I am still a total noob when it comes to DMT and these teks. I have a decent background in science/physics, but there’s every possibility that I don’t know what the hell I am doing. I’m just happy that I haven’t blown myself up, or otherwise caused myself grave bodily injury. (...yet)

Cool experiment. But when evaporating the Naphtha from a TEK after freezing, it usually does not have much Dmt left. So i guess it would only be worth when you used too much NPS initially when extracting, so it will hold back uncommonly big amounts at - 20°. Otherwise with a 'reasonable' ratio it might not be necessary? But it sounds like a cool experiment ( ) on the technical side. Interesting to hear that Naphtha freezes so fast in comparison.

Cheers

↑This (as discussed in the chat earlier).

I'd suggest, ChickenKing, that if you were going to turn it into an experiment with a bit more value it would be instructive to chill down the NPS to the usual temperature of a domestic freezer and pour it off from the precipitate into a fresh container. This would give a reference amount when weighed and the naphtha could then be chilled with the dry ice either in its new container or by returning it to the original one.

The advantage to the latter option is that the pre-existing crystals serve as nucleation points for whatever remains in solution, and also that there is less area for the crystals to spread out on, leading to a minor positive impact on final yield.

(All of this is comes with the assumption that the naphtha is fully saturated with DMT at or above room temperature. And if you start with saturation at, say, 50°C, the temperature difference in going down to -22°C is greater than going from -22°C to -78°C).

One other thing to consider is that freezing mixtures are a well-established topic and an abundance of methods for obtaining practically any (usually sub-zero) temperature have been available in the literature for decades if not centuries. Hence, in the case of a solvent that freezes above the 'usual' dry ice temperature, the minimum temperature of the freezing mixture of dry ice in that solvent is limited to the freezing point of that solvent (at least, as long as some liquid solvent remains).

For those for whom dry ice is inaccessible, we have the option of water ice eutectics (ice-salt baths) the classic one being snow mixed with calcium chloride hexahydrate (and apologies for not being able to quote, off the top of my head, the exact ratio required - there's your homework!) This mixture chills down to -55°C very cheaply.

I think the idea from the start of this threau was efficiency with time rather than with yeeld, but there's one more thing with ury ice that seems worth mentioning. There were some experiments carried out a few years back which used dry ice as a means of separating NMT from DMT where it co-occurs in certain plant extracts, most notably from Acacia confusa and Desmanthus illinoiensis. This occurs via NMT forming an auto-carbamate, something which does not form with DMT. So, if you're extracting from a plant which contains NMT this need not now be unexpected.

Happy experimenting!