Author Topic: washing extractions w/bicarb? Q's re pKa  (Read 816 times)

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washing extractions w/bicarb? Q's re pKa
« on: April 03, 2004, 06:51:00 AM »
*ducks under the nearest flame resistant shield*

Talking to someone recently telling me about their experiences with extracting dmt from plant material, he made the observation that sodium bicarbonate washing seemed to in fact extract the dmt out of the nonpolar solvent. Minimal water washing seemed to be what he thinks is needed.

Thinking about the pKa of dmt (8.68) it occurs to me that the maximum pH that bicarbonate can reach is about 9.1 and so it still partitions some of the dmt. Maybe 25%...

So probably not a good idea then. And i think perhaps water washes should be pH tested to ensure the wash actually contains something (a dissolved salts meter comes to mind as a good idea actually because contaminants are likely to be mainly NaCl, which is electrically conductive), because if bicarb solution extracts some of the dmt then so must pH 7 water (right?)

Aside from that, i am just thinking now - maybe the bicarb solution's solubility with dmt could be exploited to work as a tighter filter for the pKa of the specific materials we want out of the plant (for example, the tannins precipitate quite well around 9-10 - or something precipitates, a grey substance of some kind). A second acid base extraction using sodium bicarbonate as the 'acid'. I was thinking that then maybe use sodium carbonate as the base in the second extraction.

The thing about plant sources of dmt is that often there are other indoles present in the mixture, even cruder indoles which acid base extract to a significant degree (for example, the common strong sweet smell may actually be indole). One thing i have noticed about the bicarbonate washing is that the final result, the 'alkaloids' seem to be a pale orange/amber oil with a strong sweet smell... I think it might well be that the primary contaminant causing oily dmt extracts may in fact be some other amine inactive, such as indole, which is an oily alkaloid. I think if bicarb does indeed have a low enough pH then some other weak bases might work too - for example, sodium borate goes to pH 9 as well.

Another example of the difference that specific pH's can cause was illustrated to me in a dry acid/base extraction that utilised MgOH - the material that resulted at the end of that extraction was almost fully translucent yellow and crystallised quite readily (and would have crystallised more readily if it had been extracted into a lower boiling solvent...)

Also, some salts have two pKa transition points, it's possible that an excessive amount of base might have another effect such as rendering the desirable material insoluble (like what happens with lye lock), i imagine weak bases like amines can form dibasic salts which would lock them out of the nonpolar solvent too. Sodium-Dimethyltryptamine-hydrochloride... for example.