burnt, thank you very much for this thread!
If we are to measure by the
freebase calculator (which uses pKa calculations), then at pH 8.5, 86.32% of the Harmine will be precipitated, while only 4% of the harmaline will have done so. At pH 10, the rest of harmine will precipitate (another 13.2%, for 99.5% total). Also at pH 10, the other 61% of harmaline (so 65% total) will have precipitated.
Isnt that pretty accurate with your analysis? In the first there was only small amount of harmaline, in the second there was quite a significant amount of harmine still present (according to calculator, 13.2% of total original harmine content, which if originally was present in bigger ratio than harmaline, it would make sense that in the second precipitation there was nearly as much harmine as harmaline).
If the calculations are correct, this would also show that pH 10 you are still missing a big part of your harmaline (35% of it) which still havent precipitated.
So while I completely understand and agree with your point that you can never be perfectly sure about your separation, a product precipitated at pH 8.5 will be mostly harmine. The product precipitated with higher pH, though, will probably have significant harmine contamination, not be pure harmaline. How much contamination will depend on original ratio of harmine:harmaline, which one can simply not know beforehand. So even if after the first precipitation (ph 8.5) in your case, at pH 10 there is only 13% of original harmine, if there was 3 or 4 times as much harmine to begin with, then this 13% will be a very significant contamination, maybe more than half of the precipitation at pH 10.
But, this leads me to two thoughts: What about selectively separating through 3 different pHs? So lets say we make a first precipitation at pH 8.5 to have mostly harmine. Then make a precipitation at, lets say, pH 9.1. This middle precipitation will have another 10% of the harmine (for a total of 96.2% of total harmine content already precipitated in these first two precipitations). In this precipitation at pH 9.1, another 12% of original harmaline content will precipitate (for a total of 16.63 % of original content precipitated in these two precipitations). So this means you would have 3 products: 1 with basically only harmine, 1 with mix of harmine and harmaline, and one with mostly harmaline but some harmine contamination (amounts which depend on original ratio of harmine:harmaline in seeds).
Redissolving each of the batches and repeating process of selective pH precipitation could separate them even better.
Maybe this isnt a perfect solution but at least it lets people have a general feeling of how the separate harmalas feel in bioassays, knowing that there is some contamination. Its definitely no pure separation, indeed one would need chromatography or similar for that, but at least for the general purpouses used here I think its enough, dont you agree?
Another question I have, maybe you can test this with some pH meter, burnt: In a harmala solution, whats the maximum pH that sodium
bicarb can raise the solution to? I've gotten so many contradicting answers about this and nobody ever really tested in this specific case, which I guess is different than testing the pH sodium bicarb can take pure water to....
And ouro, I will edit the wiki page to put a warning regarding the separation not being perfectly pure, and link to this discussion here, thanks for the heads up!