Purification of opium by sublimation and condensation of alkaloids

[MeAndMissEmma]

Hi,

You will see from my other thread that I have been trying with no success to extract alkaloids from dried poppy pods, so I have been thinking of strange alternative extraction methods. Lol.

It seems to be easy enough to extract the opium from the dried pods by boiling the powdered pods in dilute acid for a few hours, filtering, and evaporating.
The tricky part seems to be the extraction of the alkaloids.

So I was trying to figure out an alternative method, and I came up with an idea to vaporize the opium, thereby subliming the alkaloids and condensing them, and leaving behind non-volatile constituents.

Something like this:

1) Grind opium into a fine powder
2) Heat powdered opium to 300C
3) Condense the vapours by some means and discard the unvaporized opium residue
4) The condensed vapour will contain alkaloids, water, some insoluble particulate combustion products, and probably some waxes and oils
5) This mixture could then be dissolved and filtered to remove the insoluble particles, and perhaps some of the waxes and oils

Perhaps a better idea would be to vaporize the opium, and pass the vapours through dilute hydrochloric acid:

This will form a solution of alkaloid hydrochlorides, with some waxes and oils dissolved perhaps, and some undissolved particles.
The solution can then be filtered to remove those particles.
CO2 and water (combustion products) will also probably have been produced, however they will both be removed when the solution is evaporated in the next stage.

The solution can then be evaporated to remove the water, hydrogen chloride, and carbon dioxide, leaving a reasonably pure mixture of alkaloid hydrochlorides.

Any non-volatile constituents (meconic acid, other plant stuff) of opium will have been left behind as a residue in the vaporization stage.

The alkaloids are definitely volatile, and by smoking opium you are getting all of the effects and yet a lot of the opium will be left behind as residue, so by definition this is purification right? (you aren't inhaling 100% of the mass of the opium)

The alkaloids could then be further purified by various other means.

What do you think of this idea?

Thanks in advance

 

[sekio]

Attempting to do this at 760mm is going to be a disaster, try with vacuum and you'll not need 300c+

Also remember that morphine and friends are acid sensitive

 

[Solipsis]

How bout basify first with a non alkali base to convert the alkaloids to freebase to improve (lower) boiling point? Sublimate and then desublimate using some (DIY) cold finger [this is not a james bond movie in which 007 had a prostate exam] and do work-up using combination of acid/base extraction and formation of alkali morphenate..

I don't think they are *that* acid sensitive if acidic solutions are routinely used during extraction methods?

How do you know when you're hot enough and sublimated your alkaloids though? Wouldn't other substances keep sublimating as you keep going hotter? Or will it be pretty obvious from the amount of vapor developed?

 

[MeAndMissEmma]

Attempting to do this at 760mm is going to be a disaster, try with vacuum and you'll not need 300c+

Also remember that morphine and friends are acid sensitive

Interesting.

So I've been thinking, just curiosity really, what would the decomposition products of morphine actually be. Would it break up into elements, or just a similar, more stable, compound? (for example, when boiled it is supposed to decompose)

 

[MeAndMissEmma]

How bout basify first with a non alkali base to convert the alkaloids to freebase to improve (lower) boiling point? Sublimate and then desublimate using some (DIY) cold finger [this is not a james bond movie in which 007 had a prostate exam] and do work-up using combination of acid/base extraction and formation of alkali morphenate..

I don't think they are *that* acid sensitive if acidic solutions are routinely used during extraction methods?

How do you know when you're hot enough and sublimated your alkaloids though? Wouldn't other substances keep sublimating as you keep going hotter? Or will it be pretty obvious from the amount of vapor developed?

Would I be correct to say that the alkaloids are meconate salts in opium, perhaps partly at least?
Yes I actually just discovered what a cold finger is when I was looking into sublimation. Thought it was an unusual name.
HAHAHA. That was funny

Hmmm. I would imagine that the alkaloid vapours would be quite dense, maybe. I mean, if you are smoking opium, I think that it would be rid of all the alkaloids within a short time (wouldn't need to smoke it for hours to get most of the active ingredients)
Just a thought.

 

[Solipsis]

No meconates are not alkaloids, they contain no nitrogen and afaik aren't active.

I've smoked opium off of foil sometimes years ago, and yeah it does produce sooty ('smokey') vapors.. wasn't really thinking of that since it is not the same as gradually increasing the temperature with something like a controllable hotplate.
It would never take hours for the alkaloids to evaporate once you get in the right range I think, but it does depend on how controlled you are heating it. Also not sure if there is any point to powdering, it melts.

The alkaloids and not even the meconates make up most of the opium.. it's just lots of latex.

Complex organic compounds normally don't just decompose into elements right away. If you go on long enough you'll be left with carbon compounds yeah, and other parts escape as things like CO2 and other gaseous oxides of nitrogen, sulfur etc.. But before that partial oxidation happens, gradually groups get oxidized I and then the compound starts to break up into fragments, I think. It's terribly complex: at every step an intermediate pyrolysis product lasts until temperatures are reached where those aren't stable either anymore and react with oxygen or acids present in the mixture etc etc etc.
(i think :> )

 

[MeAndMissEmma]

No meconates are not alkaloids, they contain no nitrogen and afaik aren't active.

I've smoked opium off of foil sometimes years ago, and yeah it does produce sooty ('smokey') vapors.. wasn't really thinking of that since it is not the same as gradually increasing the temperature with something like a controllable hotplate.
It would never take hours for the alkaloids to evaporate once you get in the right range I think, but it does depend on how controlled you are heating it. Also not sure if there is any point to powdering, it melts.

The alkaloids and not even the meconates make up most of the opium.. it's just lots of latex.

Complex organic compounds normally don't just decompose into elements right away. If you go on long enough you'll be left with carbon compounds yeah, and other parts escape as things like CO2 and other gaseous oxides of nitrogen, sulfur etc.. But before that partial oxidation happens, gradually groups get oxidized I and then the compound starts to break up into fragments, I think. It's terribly complex: at every step an intermediate pyrolysis product lasts until temperatures are reached where those aren't stable either anymore and react with oxygen or acids present in the mixture etc etc etc.
(i think :> )

Yeah that's true.

That's interesting, thanks for the explanation

I've always been curious about why morphine and some other alkaloids discolour upon exposure to light/air.
Is this due to a chemical reaction or, maybe, some change in crystal structure or something?
Not sure of the exact words but the Merck Index says "No loss of potency has ever been observed" in morphine that has discoloured.
I suppose that is why opium turns from white to brown/black too.

 

[Solipsis]

Opium forms as the latex oxidizes and solidifies, again.. you are seeing mostly the plant sap itself with compounds like the alkaloids making up just a small part...

Only small fractions of a substance need to oxidize sometimes for the overall color to go from white to a dull grayish tone. When Merck says no loss of potency has been observed you should read that as "no significant loss of potency", but the oxidation may be limited and still significant enough for the color to change.

Either there is change or there isn't, you can't really get discoloration without a chemical having reacted.

There are indeed things like polymorphism of crystal structure which can change certain physical properties of a compound but not their chemical and physical potential once you would dissolve these different forms. Usually though I think that what changes most upon crystal structure change is transparency / opacity and not change in color. The bigger and more perfect crystal structures are and the less fine the crystal size, the less scattering of light will occur and the more transparency there will be. Finer crystals with an appearance that is said to be white are still a "colorless" substance, the white appearance is a result of the entire light spectrum being evenly reflected. Color would be an unevenness in the reflection spectrum... for example metal particles such as in colored glass can be responsible for that.

In rare cases the nanoscopic structure of a material can cause it to have a colored appearance rather than particular chemicals being involved...