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Problem separating harmine and harmaline

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ijahdan

ijahdan

Rising Star
Ive recently finished an extraction of syrian rue and at the final basifying stage tried to precipitate harmine first, using sodium bicarbonate, followed by harmaline, using sodium carbonate.

The first precipitation went well. I added a supersarurated solution (hot) of sodium bicarbonate till no more alkaloids crashed out, let it settle overnight. Next day there was a thick layer of tan alks at the bottom of the jar, presumed to be harmine.

I then siphoned off as much liquid as I could. This was a clear, pale yellow/green in colour, compared to the deep red of the original solution.

I then added sodium carbonate solution, but no more precipitation occurred. I even tried adding some sodium hydroxide to raise the pH more but still nothing.

Does this mean that the sodium bicarbonate somehow precipitated both alks or does some rue contain only harmine?
 
Unlikely that the bicarbonate precipitated everything, but the ratio of harmine:harmaline in the seeds, can vary due to a few factors, time of harvest being a key one.

Did you see this thread already?
 
Its possible there was very little harmaline, yes.

Also it may take a while to precipitate, leave in the fridge for a day and see what happens. Also it might have precipitated but you can barely see it, so try to filter anyways.


Lastly, you can always use a TLC kit to know if your product contains harmine, harmaline, or a mix, plus its useful in general for all this plant research and drug harm reduction.. So if you ever can afford I recommend :D
 
Thanks for that link chan, Ive read a lot of the harmala threads but never that one. Wasnt really aiming for high purity anyway, just wanted to see if there was a big difference between the two alkaloids, and it sounded like a simple enough procedure. I'll definitely look into getting one of those tlc kits for future experiments.
 
Like endlessness mentions, it is very possible there was very little harmaline in the seeds.

It is also very possible that since you added a "hot sodium bicarbonate solution" to your solution, that both the harmine and the majority of the harmaline crashed out together. It's best to use a digital thermometer to test your solution before you precipitate, make sure it is room temp (76 degrees to 82 degrees) before precipitating and make sure the sodium bicarb solution you add is room temp as well, not hot, and not cold. I've noticed Temperature plays a major role in affecting the ph at when these will crash out. Just doing a search on-line will reveal that ph levels of solutions are heavily influenced by temperature.

Many years ago I noticed that I could get both harmine & most of the harmaline to crash out together in a solution that was over 100 degree F, and by adding (just like you did) a hot solution of sodium bicarb to it as well. I also scratched my head thinking there was no harmaline in the seeds, but usually there is at least 1/3rd harmaline minimum in there even from hot grown summer seeds. I re-dissolved everything after another manske on it all, then re-precipitated all at room temp, with room temp sodium bicarb, then I noticed a clear sep of the harmine (with room-temp sodium bicarb) from the harmaline which crashed out later with room temp sodium carb from the room temp solution.

This fact is clearly evident when we measure the pH of water @ 0 deg C we find it to be 7.47, but the same water at 100 deg C will have a pH of 6.14 ! so there a definate corelation of pH and temperature . Temperature plays a significant role on pH measurement. This is a well-know fact for most users of pH test equipment. However, the temperature affects not only your sensor but also your sample. All solutions will change their pH value with temperature. This is a result of the shifting of the chemical equilibrium of the components, mainly of dissociation.
 
When I add baking soda to hot water, it fizzes. I guess that this is CO2 escaping, signalling the conversion of baking soda (NaHCO3) into washing soda (Na2CO3.) So I do not use hot water to make a baking soda solution if that is specifically what I want.

Also I wonder if using excess baking soda could be causing shifting equlibria and unexpectedly excessive precipitation of harmaline. Maybe a proper chemistry wizard could chime in on that.
 
You added too much Bicarbonate and caused most of the harmaline to also crash out. When I have done this I was very careful to add only a few drops at a time until I saw strong precipitation. As you get close you will begin to see some brownish precipitate form around where each drop lands. You have to be very slow and careful here or you will overshoot the pH and precipitate more harmaline. Keep it at room temperature, there's no need to heat anything. If you start to see an off-white precipitate, you've gone too far. Clean harmine freebase is brown, while harmaline is off-white (maybe white if ultra pure). A mixture of the two is tan colored.

FYI the yellow tint never goes away - you can keep adding base and always, 5-10% is left behind in solution.

This really needs to be done at least twice to ensure that you have something that is mostly harmine. Each time you separate maybe 80/20 harmine/harmaline, depending on how well you control the pH. So if you do it well twice, you get something around 95% harmine which is probably good enough for most purposes.
 
Thanks everyone for expanding my chemical knowledge. Ive been lulled into a false sense of security by how easy most extraction teks have been, and how much leaway there normally is with the quantities of reagents. Obviously this one requires more precision.

Ive washed and dried the precipitate now anyway so Ill see what these mixed alks are like first and when I get another bit of free time have another go at separation.
 
Agree with Acrologist, as there is probably no benefit from overdoing the sodium bicarb either, his method of careful titration makes alot of sense, and of course we are all in debt to the many fantastic teks endlessness & friends have contributed for the entire process from beg to end, many thanks. :)

There was a second time my solution was very hot (over 120 degree F) in which I added hot sodium bicarb, and actually caused all the harmaline to crash out with the harmine, as in zero precip, I then went back and re-mansked, re-dissolved into hot water, let cool several hours to room temp (76 degree F) reprecipitated with room temp sodium bicarb and recovered 12 grams of harmine and then later using sodium carb precipitated 10 grams of harmaline, whereas before I had zero grams harmaline precip from a 120 degree F solution with the later addition of sodium carb, since those two times, I learned my lesson and only always precip from room temp solution. This problem actually caused me much heartache, as it took me several months to find the solution to the problem, as I kept repeating the same mistake over and over for over 2 months, thinking it was just bad seeds, always using 120 degree solutions to precip from.

The below link says that pH is decreasing slightly with increase in temperature, which is what was happening to me, the soution was so hot, that I could get all the harmaline to precip with the harmine when using sodium bicarb to precip from very hot solution, once I lowered the solution to 76 degree F, problem solved.

chemwiki.ucdavis.edu

Temperature Dependence of the pH of pure Water

chemwiki.ucdavis.edu chemwiki.ucdavis.edu
 
I had this same problem separating harmine. I saturated room temperature water with sodium bicarbonate, noticing it's not NEAR as soluble as sodium carbonate. Then I added the solution to a room temperature harmala solution. Not noticing any significant color change, I kept adding bicarbonate solution until the harmala solution was double the original amount. Confused, I decided to add baking soda directly into the harmala solution until finally seeing a significant color change. I allowed it to sit for a couple hours, filtered the precipitates, then added sodium carbonate solution to find nothing more precipitated. I took the precipitates and washed them in water to remove the excess baking soda. After soaking the precipitates in room temperature filtered water, I collected the precipitates again to find that it was all brown harmine. The harmaline freebase REDISSOLVED into the water. Thought freebase harmalas weren't water soluble?
 
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