How does one filter out the activated carbon when doing a decolorization? I read somewhere in a post that the carbon not only pulls out impurities but mixes in with the solvent and spice also. The wiki says to "filter" it out, but with what? How exactly is this done? Won't the dmt be caught in something like a coffee filter and even if, not won't the dmt be left behind since the carbon can hold on to some of the dmt? An MIT course says to use Celite to help with pulling out the AC from the solvent but 1) I can't find it anywhere and two how would this make the spice go through the coffee filter? Thanks.

celite is just diatomaceous earth, you can buy it as nontoxic ant killer at the garden store. The best way to filter out AC is to filter through a pad of celite using vacuum filtration. This is obviously not available for everyone though.

AC has very fine particulates that will go right through the coffee filter or clog up the filter paper, even when using vacuum. This is why using celite is best. Gravity filtration is really a pain in this case, not even an option. Worse than filtering rue. You CAN try adding a bit of celite to the solvent mixture with the AC, and then gravity filtration. I have done this before and it is possible.

AC will adsorb some DMT, don't use too much, little goes a long way, DMT will stay dissolved in the solvent.

Thanks for the info. A slight correction though, from the video I watched on recrystallizaton they said that vaccuum filtration is not best because it cools the solvent too much and that heated gravity filtration is better.

So if the spice is dissolved in the solvent it will go right through the filter? That makes sense. I feel like there is a significant risk to doing this so I am hesitant to even do it. Unlike most parts of extraction, if you screw it up you can always fix it. It seem that if one uses too much carbon the spice is not retrievable. How much does one use? Do you have a ratio of spice:solvent:AC and spice:solvent:AC:celite? Why is celite not mentioned in the wiki? Can it be done without it? Sorry for all the questions. I'm deciding whether or not I should try this. Thanks again.

Your question was about filtration of AC, not re-crystallization. Try filtering AC/celite by gravity and see how you like it. be prepared to stand in front of it for a couple hours and lose a lot of yield. If the video was talking about AC its bogus, don't believe everything you hear on on youtube

Vacuum does cool the solvent, but if your doing AC wash, it should be like 100X as dilute as it would be in a crystallization solvent, so cooling is not an issue... Worse case you just heat it back up again to get it all dissolved...

I do prefer using gravity filtration if im just filtering out some anhydrous MgSO4, because it filters easy and is simpler..

look up the procedure using google, its standard practice. AC washes for DMT are not normally necessary, most extractions go cleanly enough that they are more work than what is worthwhile... esp without proper equipment, it good to do before re-x, it will remove a lot of the yellow colour from the solvent.. But if you do a good recrystallization, you can achieve the same result without AC in most cases. AC is good if its so dirty/yellow that you cannot get the crystals you want without first the AC wash

This video is part of some sort of MIT course and they say not use vacuum filtration. Maybe I am misunderstanding something or maybe the rule doesn't apply for dmt. I'm definitely no chemist. Here's the video @ 7:27

https://youtu.be/7LBGQHjgHEw?t=447

Thank for the info. I'll probably just take your advice from this and your comments from my other post and do a good re-x after an sc wash and skip the carbon step. Thanks!

interesting, i guess it does depend on the kind of charcoal you have, particle size and what not. Then gravity does work the same way you would do drying with mgso4.

but not everyone gets their charcoal from sigma aldrich (because it costs hundreds of dollars for burnt wood), and if its too fine it cloggs your filter and its game over

+ i like using celite because it adsorbs similar to AC, so its doubley efficent. Even pulling through a pad of celite alone does a great job at cleaning. I usually do the washing warm, but not near boiling. I trust real experience over some poorly made digital lab manual

How much AC do you use? Should it be weighted per volume or per estimated amount of impurities?

BTW: I tried diatomaceous earth (fine powdered, food grade) for filtering rue - it works amazingly and removes all the plant gunk. Unfortunately, the yield loss was huge, more than 50%! Maybe it's because the plant matter clogged the celite and keeps alkaloids trapped inside even if the filter is washed with clean solvent (hot water in this case).
Maybe it would be wiser to use Celite for later fine filtering, not initially.

The best results with both DMT and harmala were obtained by alternating precipitation/recrystallization and vacuum filtration.

With DMT, single recrystallization in heptane was sufficient.

Also look for sodium carbonate solvent wash - this alone should work for removing water soluble impurities.