Acid-Base Extraction of Mescaline from San Pedro

Prdy2GO:

Step 1: Aqueous Extraction

First, you need to prepare a "tea" from your cacti. If using dried cactus, powder it. If using fresh cactus, chop it to small pieces and then puree it in a blender. At this point, it is a good idea to weigh your cactus and record the weight. This will be helpful further on in the process. Put the cactus in your stainless steel pot and cover with just enough water to make a soup. Add some acid to make the pH of the soup fairly acidic. If using citric acid, you want to add about 3 grams per liter of water. Boil the cactus about 20 minutes. If you use sufficiently acidic water, there is no need to boil longer than this. After boiling, strain out the cactus chunks (the marc) and save the liquid. You want to do three acidic water extractions on the cactus. Combine the 3 liquids and toss the marc on your compost pile or dispose of it in some other non-wasteful manner. If the volume of liquid you have is large, you may want to boil it down to a more managable quantity.

Step 2: De-Fatting

Once cooled, the next step is to de-fat the solution. This step will remove the fats and many other non-alkaloidal plant matter. Make sure the solution is acidic (pH 4 is good) before doing this. If the solution is acidic, the alkaloids will be in a salt form which is soluble in water but not in xylene. Pour the solution into a glass jar (or separatory funnel, if available). Add 25-50% of the solution volume in xylene. For example, if you have 200ml of solution, add 50-100ml of xylene. Put the lid on the jar and gently turn the jar over 50 to 100 times. Do not shake the mixture vigorously as this could result in emulsions that will be difficult to separate. (If you do end up with an emulsion layer, which looks like a thin layer of poorly separated bubbles, bathing the jar in hot water can help separate the emulsion. If the emulsion layer is thin enough, you may wish to just discard it rather than taking the time to let it separate.) Once mixed, let the jar sit and separate out into the different layers. When this is done, you will have a top layer of solvent, a middle fatty layer, and a bottom layer containing the acidic aqueous solution (and the alkaloids).

If you are using a separatory funnel, drain out the bottom aqueous layer and throw away the top two layers. Alternatively, use a turkey baster to siphon off the top two layers and discard them. (Make sure you dispose of all solvents safely! Do not flush it down the toilet if you have a septic tank. If pouring it down a sewer-connecting drain, make sure to wash it down with large amounts of water.) You will likely find that the turkey baster only gets off most of the solvent and fat layers. To get the thin layer that the turkey baster can't get, try this trick. Siphon off all of the remaining solvent and fat layers, as well as some of the top of the aqueous layer. Put this liquid into a tall thin glass container (a graduated cylinder or test tube, for example), and let it separate back into layers. Then, use an eye dropper to get off the solvent and fat layers, then add the remaining aqueous solution back to the main jar.

There is one other possibile approach to separating the layers. Because xylene freezes at -47.7 degrees Celsius, a separation can be done in the freezer. Put the container in the freezer and let it sit for a few hours until the water has frozen solid. The xylene can then be poured off and discarded. I do not know if this will work for defatting, as I do not know the freezing point of cactus fats. If the fats freeze at freezer temperatures, it may not be possible to pour them off with the xylene. This freezing technique can certainly be used later on in steps 4 and 5 to separate the xylene and water layers, however.

Repeat the de-fatting process two more times, or until you no longer get a fatty layer after separation. Make sure that you have good ventilation through the whole de-fatting process (or any time you are working with xylene). If you begin to feel light-headed or nauseous, or get a headache, go outside immediately and breathe fresh air until you feel better. Also, make sure there are no open flames or sparks as xylene is quite flammable.

Step 3: Basification

After de-fatting, slowly add sodium hydroxide to the aqueous solution until the pH is up around 10. Rather than adding dry sodium hydroxide, it may be wise to prepare a solution of sodium hydroxide in water, and add this. Be careful when mixing the sodium hydroxide and water, as the mixture will cause an exothermic (heat producing) reaction. Do not prepare the mixture in heat-sensitive containers. When working with sodium hydroxide, remember that it is a highly caustic material and can burn you badly. Avoid contact, especially with the yes, and if any gets on you wash the spot immediately with plenty of water. It is highly recommended that you wear protective gloves and goggles when working with sodium hydroxide or other hazardous chemicals.

Be aware that once you do this step, you need to continue the extraction at least up through the xylene extraction because leaving the alkaloids in a strongly basic solution will cause them to start breaking down after several hours. Making the solution basic turns the alkaloids into their free base forms, which are soluble in xylene.

Step 4: Extraction of Free Bases

Once the solution is basic, xylene using the same ratio as used during the de-fatting process. Again, mix the solution thoroughly but gently to avoid emulsions. Let the solution sit, and it will separate out into two layers. On the bottom will be a basic aqueous solution, and on the top will be a xylene layer which now contains the alkaloids. Using either a separatory funnel or a siphoning process, collect the xylene layer and set it aside. Since there will still be significant alkaloids in the aqueous layer, repeat this process two more times. Combine all the xylene and discard the remaining aqueous solution.

If you are using a separatory funnel, gas may be formed when adding xylene to the basic solution. To prevent pressure from building up and potentially leading to an explosion, vent the separatory funnel occasionally. If you are using a jar, you should remove the lid.

Step 5: Salt Formation and Extraction

The next step is to add acidic water to the xylene. This will cause the alkaloids to convert to their salt forms, which are soluble in water but not xylene. If using hydrochloric acid from the hardware store, it will already be diluted and may be usable as is. Read the label to find the concentration. One source says, "HCl from the hardware store is generally between 24%-36% HCl. This is far from dilute. Indeed, upon opening the container, a visible plume of white vapor can be seen creeping out of the bottle. First the lungs start to burn, then any skin which is exposed to the air starts to sting... This should be diluted, especially if it is going to be worked with without a fume hood. 20 drops acid per 500ml of water may even be sufficient."

If using vinegar (acetic acid), it comes quite diluted (around 5%) and should be used as is. It would probably be best to use plain white vinegar. I do not know what else is in vinegar other than water and acetic acid, but it is likely other chemicals remain from the original wine, and this may affect your final product. There should not be any harmful products from using vinegar, since it is a food-safe product, but you may not get nice crystals after evaporation.

If using citric acid (which is the recommended choice), prepare a solution of citric acid powder with a small amount of water. I recommend using citric acid because unlike hydrochloric acid, it is food-safe and safe to handle, and unlike either hydrochloric acid or vinegar, it is available in pure form. I have been told that using hydrochloric or acetic acid has the advantage that both are volatile and that excess will evaporate off, unlike citric acid. However, since neither are easily available in pure form, it is still probably better to use citric acid. Beware that if you do use hydrochloric acid and let it evaporate, the fumes can be hazardous and the evaporation should not be done where you might breathe in the vapors.

For this step, it is useful to have some idea how much alkaloid should be in your cactus extract. If you weighed your cactus before extraction. Trichocereus pachanoi has been analyzed with mescaline contents of 0.025-0.12% fresh weight (0.331-2.0% dry weight). Mescaline is usually around 50% or more of total alkaloid content. You will want to add an equimolar quantity of acid to the solution.

If you can't or don't want to estimate the alkaloid content, Trout gives the following work-around: add very small quantities of acidic water to the xylene, let separate, and then collect the water layer. Check the pH of the water, and it should be neutral. Repeat this with small batches of acidic solution until the water layers come out acidic. Trout points out that "Something to keep in mind is that neutralization won't always be immediate. pH should be checked after a few minutes to see how it is, adjusted if needed and rechecked a few minutes later."

If you are using citric acid and you are not worried about having citric acid powder in the final product, you can just add enough acidic water to make the solution slightly acidic, and repeat this once or twice, then combine the extracted water layers. As citric acid is both food-safe and a solid powder, this is a sloppy but safe approach. Shulgin suggests that this may be a better approach than stopping when the water layers stop coming out neutral: "My gut feeling is that there may be quite a bit of alkaloid still in the xylene, and maybe a couple of extracts with more aqueous acid would be useful. True, it may load the product down with excess citric acid, but the increased yield might be worth it."

However you approach it, after the acidification and water extraction step, discard the xylene. Again, make sure to dispose of it in a safe manner.

Theoretically, this step could be skipped entirely, and you could just let the xylene evaporate. This would leave behind mescaline (and the other alkaloids) in free bas form, which is an oil. This is not recommended however, as mescaline oil is highly caustic and it would burn your skin to touch it. Since its an oil, it would also not be possible to put into capsules. Perhaps you could put the oil into some acidic fruit juice and safely drink it, but it is still preferable to go through this step to produce a salt form. Perhaps it may even be smokable, though I know of no reports of anyone trying to smoke (or vaporize, rather) free base cactus alkaloids. The boiling point for mescaline free base is around 180 degrees Celsius. One final concern is that free base mescaline oil may not have the shelf life of a salt.

Step 6: Evaporation

Finally, pour the water into a large pyrex baking pan. Set it in a protected location to evaporate. Let it evaporate slowly at room temperature rather than using heat, as this will give you a better chance of producing nice crystals. After the water has fully evaporated, scrape up the crystals (or whatever solid mass you end up with) and put them in capsules or a vial for storage.

Keep in mind that when measuring doses, there are a few things to consider. First, your extract will contain all the alkaloids from the cactus, not just the mescaline. Second, depending on what acid you used in step 5, you will have different salts of the alkaloids. For example, if you used citric acid, you will have mescaline citrate (as well as citrate salts of the other alkaloids). If you used vinegar, you will have mescaline acetate. If you used muriatic acid you will have mescaline hydrochloride. The doses of each will be slightly different, due to the different molecular weights of the different acids. Because of these factors, you will need to figure out the potency of your material before you can weigh doses accurately.

Conclusion

Do make sure that you follow all safety instructions religiously. Failure to excersize caution can easily lead to harm and even death. To stress this point even further, I will close with some comments from Trout:

"It seems like it does not matter how many times you tell some people things, lots of them decide what THEY think is really important and items like solvent exposure and not using plastics or solvents stored in plastics (or even the use of slow and careful heating) get forgotten whenever it is not convenient to follow the instructions.

Its very distressing how careless some people are. Worse, people like this often expose not just themselves but family, children and pets with no thought or concern.

You would not believe some of the letters I have gotten. Some of them I almost can't shred fast enough.

I'm sadly coming to believe that a simple citrate tea (lime not lemon) or else dried outer flesh consumed as powder are the only safe approaches the general public is capable of handling responsibly."

References

[1]Fletch. Private e-mail. December 7, 2001.

[2]Shulgin, Alexander. Private e-mail. November 24, 2001.

[3]Trout, K. "Sacred Cacti." Second edition, 1999: Chapters 4, 6 and 10.

[4]Trout, K. Private e-mail. December 1, 2001.

Starlight:

Just replace steps 5 and 6 above with the step below:

This method relies on the low solubility of mescaline sulfate in very cold water.

(this is not tested from personal experience, but sourced from Trout: Sacred Cacti and Selected Succulents, 1997)

Step 5: Salt Formation and Crystallization

Once you have separated the organic solvent, dark (or in the case of recrystallization at least yellow) with alkaloid and impurities from the basic solution, extract it with dilute sulfuric acid. Use only as much as is required to neutralize the alkaloid bases. A little excess at this point is not desirable, but not of concern. Separate the small volume of aqueous solution now containing the mescaline sulfate and other alkaloid sulfates.

It will need gentle heat to reduce it somewhat, but do not let it become thick, or overheat. Take this solution while warm and insulate it well (a small styrofoam shipping box will work as will being carefully wrapped in towels). Stick the whole thing in your refrigerator until quite cold (near 0C) but do not freeze.

The object is to retard the rate of cooling to as slow as possible. This will cause the formation of large, beautiful crystals. If you chill rapidly a crystalline mush of many tiny crystals will form, trapping impurities.

Take the mother liquor containing the crystals and pour through a buchner funnel. Allow the air to keep sucking through the crystals. Briefly squirt a bit of ice cold water through the crystals to rinse them of any remaining solution. Turn off the air flow briefly and immediately dump out the mother liquor and ice water rinsing and save.

Rapidly resume air flowing through the Buchner. Then quickly rinse the crystals with a little acetone to remove the remaining water. Let the air keep flowing to pull off as much liquid as possible. (If one has access to a cold room all of this will be more efficient).

Take the filter and immediately dry in a warm oven (120-120F) with the door open. Package as soon as dry and keep away from light, heat, moisture, air.

Second and third crops of crystals may be obtained by reducing the mother liquor further (do not allow to become thick) and again chilled. By the third or fourth time other alkaloids will begin to crystallize. These may be grey in colour and have a plate-like structure. They should be easily distinguishable from the beautiful yellow or white needles and prisms of mescaline sulfate.

The sulfate salt can be converted to the hydrochloride salt by acid base and evaporation if so required.