I've been reading through the A/B extractions and when using HCL acid there seems to be a variance in the amount used. I would like to minimize the volume of water used in an extraction. What would be a ratio of water/~30% HCL acid used per gram of MHRB using the minimum amount of HCL/water solution?

opinions will vary here,
i'd say, just as much as is needed to bring it to the ph you want

Normally I add enough to bring it to pH 1. But theoretically one should be able to concentrate that further and use less water. It takes 1 hydrochloride molecule to bind with 1 molecule of dimethyltryptamine to make DMT.HCL and we should only need enough water to mix well for conversion. So, let's work out how many mLs of ~30 HCL acid one needs to use with say 1 Kg of MHRB, then add a little more for good measure. Would using too acidic of a solution hurt the extraction?

Are you using powdered MHRB? If so, the Acid (De-fatting step) is not necessary as there is not much material to be broken down in powdered bark. This Acid step is typically used for extracting from green, leafy plant material as it breaks down the fibrous cells. Therefore you can go straight to base (STB).

If you are doing the acid step for the practice then go for it! But you may save yourself some time and go STB with very similar results.

thankyou

I use powdered MHRB but prefer to get my DMT.HCL first, wash, then basify for a clean DCM extraction. I am new to this site but not to organic chemistry.

A pH of 1 is really overkill, usually people use a pH of 3-4 irrespective of acid and everything goes fine. Also, how do you really know your pH? pH will also be influenced by the bark's acids as well as the temperature, since pH is temperature dependent.

And what is this with the use of less water? Are you not having enough? Do you live in Kalahari dessert? Anyway, water can always be boiled off I think people have success boiling off water!

As for the extraction per se, you'd be better off using more than less water since it gives more space for the extracted stuff to diffuse into.

Finally, you really do not want all these calculations; unless you got something else in mind (especially with this "using less water" thing) that I might have failed to grasp from your post!. The calculations are easy to do, but of very little practical significance. For instance, assuming that MHRB has 1% dmt and that 1g MHRB has 10mg dmt, that works out to 53 micromoles dmt that need 53 micromoles of HCl or 0.0065 ml of a 30% HCl solution.

But how this can ever be useful?

Thank-you Infundibulum, those were the numbers I was looking for. The reason for my question is my glassware is small and it would be nice to have to deal with the least volume of solutions possible without risk of loss. I think others on this site might find that useful too.

Using the absolute bare calculated minimum of water would probably be a disaster. If you have small gear either upgrade or do smaller lots, you're really going to want the extra water. Just buy a SS stockpot and reduce the excess after the acid boils. That will solve all your issues

You're welcome. Still I do not understand you logic here, since if you use the least volume of solutions you will lose yield no matter what. More water=often better extractions.