MrEDuck
Well-Known Member
So extractions are a topic that comes up on here a lot, and rather than retype the same answers and procedures over and over again I thought I'd make a single thread on the topic and try to be really thorough and save us all some time.
Now before we get into an actual procedural write up lets go over a few things. Performing the procedure discussed here on many natural products is illegal in many locations, know your local laws and please abide by them. Choosing to do otherwise is at your own risk. For those interesting in learning the technique tea leaves are great for practice as I do not know of anywhere where either tea leaves or caffeine powder are illegal.
Please remember safety first and take two for safety before doing anything with chemicals ever. Always wear long sleeves and pants and shoes that cover the whole foot and proper lab attire when working with chemicals. Wear all appropriate personal protective equipment including but not limited to safety glasses, good gloves (in this case nitrile gloves that are at least 8mil thick are highly recommended, gauntlets are even better, check the chemical resistance of any gloves before using as sometimes they can be worse than nothing. A simple google search takes almost no time but can make a huge difference), and a proper mask or respirator if adequate ventilation is not available.
So first off what do we mean when we talk about extractions? Obviously for us it's always about getting some kind of active out of some type plant or fungus material. Generally these are done as either solvent extractions or acid base extractions. A solvent extraction involves washing or soaking the material with a solvent, typically a partially polar solvent like an alcohol, or a nonpolar solvent like ether or hexane, though water extractions are quite common, but I really hope you can handle that one by yourself, as it is literally as simple as making coffee. Examples would be making BHO or extracting cactus alkaloids and other nonpolar material to make cactus tar from a San Pedro with an alcohol. These are pretty straight forward and I'm not going to go into much detail. The variables are what kind of solvent you use, the length of time the extraction is done for and what temperature it is done at.
Acid base extractions are a way of extracting alkaloids based on their chemical properties and solubility. Alkaloids are naturally occurring compounds which contain a basic nitrogen group. Basic in this case refers to acids and bases, it means the N atom is able to accept an acidic proton. This gives alkaloids some interesting properties. The one we're most interested in here is it's solubility in various solvents. In their freebase (when the N is not protonated, or bonded to an additional hydrogen atom) form the alkaloids we're interested in are generally not water soluble, but are soluble in nonpolar solvents. The protonated form is water soluble owing to the fact that they form salts when they get protonated, for example a hydrochloride salt forms when hydrochloric acid is used on the alkaloid, the H atom binds to the N atom creating a positively charged molecule and the chloride ion binds to this because it has a negative charge. Both forms are usually soluble in alcohol because it is partially polar, but that same property makes alcohol dissolve lots of other stuff you don't really want.
Not all bases (or acids) are created equally though. And this is one of the properties that allow us to separate these alkaloids. In chemistry we measure the relative strength of acids and bases with a number called pKa. The lower the pKa the more acidic a substance is. To give you an idea of what this means a very strong acid will have a pKa of 1 or less, they will fully protonate water in solution. Compounds with higher pKa values are bad proton donors, but will be protonated pretty easily. For example mescaline has a pKa of 9.56. This means that in if you put a gram of mescaline into a solution with a pH of 9.56 50% of it would be protonated while the remaining half would remain as the freebase. Shifting by 1 point in either direction would make it 90/10, so at 8.56 90% would be protonated and 10% would remain as the freebase. Another point shifts it to 99/1. Going further doesn't really offer much benefit. When doing an extraction you want to get your pH about 2 points higher to do your extraction to get almost all of the alkaloid as freebase that you can collect with the solvent but at the same time keep the pH as low as possible to avoid forming an emulsion (a mixture of a nonpolar liquid and a polar one, like oil and vinegar in a salad dressing) that will take forever to separate.
The basic procedure is the same for all A/B extractions. First you want to put your material in an acidic solution (it only needs to be slightly acidic, a pH of <5 is generally sufficient) and extract with a nonpolar solvent to defat the solution (note, filter out your source material prior to separating, it makes it so much easier, then return it to the aqueous layer after separation each time). While this step isn't always strictly necessary it improves product purity and makes the work easier as it gets rid of many compounds that can cause the mix to emulsify at higher pH. It is essential when working with cacti. To extract you add a small amount of the nonpolar solvent (about 1/5 of the volume of the aqueous layer), and ideally you put them in a separatory funnel (a 500mL one costs like $25 and make extractions so much easier) and shake them up (invert it and turn the stopcock to vent it every 15 seconds or so) thoroughly. Then allow the mixture to separate and discard the nonpolar layer (if you have a still you can distill the NP solvent to recycle it, it's good for your wallet, the environment, and means you need to purchase solvents less frequently which can reduce risks to you).
Now you raise the pH of your aqueous layer to the pKa + 2 of your desired substance. You should see a (usually) white precipitate form (some chems are different colors but most of the ones we're interested in are white). Now extract again with the nonpolar solvent, then separate and save the NP layer and the aqueous layer. Soak your source material (MHRB, cacti, etc) in the aqueous layer some more (you will probably need to adjust your pH), give it at least 4 hours this time, then repeat the extraction again. Now do it again but let it go overnight this time. Extract again. Repeat again giving 12 hours or more and extract, then go one more time overnight. This is a total of 5 times over the course of 2 to 3 days which is my standard general procedure. As you get familiar with your source material you may find you want to do fewer pulls or more pulls.
Now pool your nonpolar layers and rinse them 3x with a small volume (depending on how much nonpolar solvent you have it could be anywhere between 10-50mL) of a concentrated brine solution with a pH of pKa + 2.5 (pH the water then add as much salt as it can dissolve). This pulls out any polar stuff that managed to hitch a ride and helps your purity.
Now we're ready to crystallize. Generally this is done by adding acid to form a salt. DMT doesn't like to form stable salts, but you can use fumaric acid to salt it out, otherwise reduce the volume of your nonpolar solution by 50-75% and stick it in the freezer overnight to get it to precipitate. For other stuff there's several ways to salt it out. The best method is bubbling dry hydrogen chloride gas through it. If you are using this document as a guide you probably don't have the skills to do that though. Dry HCl is nasty stuff that you really don't want to breathe in or have it come into contact with your mucous membranes. If you've ever opened a bottle of con HCl outside a fume hood while breathing in without a respirator you'll have a little taste of what this can be like. The dry gas is much much worse. I got a tiny tiny whiff once and I hacked up some vile looking shit. It probably wouldn't have looked as bad if I wasn't a smoker, but then I wouldn't be that surprised if the tars actually protected my lungs a bit.
So since dry HCl is out let's look at some other ways. Many light organic acids will be soluble in the nonpolar solution and will react with and precipitate your alkaloid. Fumaric acid mentioned above is one of these, another readily available one is glacial acetic acid. I like hydrochloride salts. They're generally quite stable over the long term, easy, and cheap to make from readily available substances, and are commonly the salt for which doses of a given substance are listed as. To make them without dry gas put about 0.25mL of con HCl in about 5-10mL of isopropanol that's at least 91%. Anhydrous is even better. (You can dry 91% IPA by adding dry epsom salts (bake at 250F+ for at least 1 hour) to it and letting them sit for a few minutes before filtering. You want to do this 2-3x to ensure the water has been absorbed. Leave some of the epsom salts in the liquid if you're storing it for any amount of time and filter them at the time of use). Now add this slowly to your nonpolar solution and watch beautiful white crystals start crashing out of solution. Filter off the crystals, and hit the solution again to see if anything else precipitates. Repeat until no more crystals form.
For the math lovers among you the 0.25mL of con HCl has about 3mmol of HCl, so it should precipitate ((molar mass of substance HCl/1000)*3)g of product per addition. If you're doing a larger scale extraction you can increase the amount of HCl used initially but keep it reasonably dilute (no more than maybe 1mL of HCl per 5mL IPA) to make sure it gets into the NP layer rather than forming a separate layer, shaking the solution after adding the HCl can help makes sure it all gets into contact with the product, but it's not as pretty to watch so try to get a good first crop anyway. Appreciate the beauty inherent in science.
So a step by step write up would look like this.
1. Place the substance you are extracting into an appropriately sized glass or stainless steel vessel. You want to be able to have your starting material completely submerged with an inch or so of water over it and have a few inches of room above it before the rim. You don't want any of this stuff spilling!
2. Make the water layer slightly acid. 3-5 should be just fine.
3. Put the starting material, water layer and nonpolar solvent (about 1/10-1/5 of the volume of water) in a sealable container (again glass or stainless steel just like everything else used in this tek) and shake the hell out of it. Vent it every 15 seconds or so to avoid a pressure build up.
4. Filter the source material out and then separate the liquid layers. Discard the nonpolar layer.
5. Put the source material and the aqueous layer back together and adjust the pH of the solution to the pKa of the desired product + 2
6. Allow to stand with stirring or other mixing agitation for 10 mins. Check pH, adjust if needed, mix for another 20 minutes.
7. Place in sealable vessel with nonpolar solvent (about the same volume as was used in the defatting step) and mix thoroughly, filter the starting material and separate. The source and aqueous layer go back together, save the nonpolar layer.
8. Readjust pH of aqueous layer if needed and allow to soak for 4 hours. Extract and separate again. Again recombine the aqueous layer and the source and save the nonpolar layer.
9. Do another 4 hour run on the source, and separate again. Then repeat twice waiting 12-24 hours to ensure you get all of teh desired product out.
10. Pool nonpolar layers and rinse 3x with a small volume of concentrated brine of pH=pKa+2.5. Save the nopolar layer.
11. Crystallize as above either by salting or freezer precipitation as discussed above.
Some notes. There are many suitable solvents. Heptane works very well for DMT because while it goes into solution quite well it can also be gotten out by concentrating and freezing. Xylene and d-limonene are both quite popular for mescaline. Caffeine isn't very picky about the nonpolar solvent. In general most things aren't, but look around to see if others have found an optimal solvent. Substitutions are generally ok. Try to stick to things that have fire diamond ratings of 3 or less for flammability, 1 or less for health, and 0 for reactivity for solvents.
Now before we get into an actual procedural write up lets go over a few things. Performing the procedure discussed here on many natural products is illegal in many locations, know your local laws and please abide by them. Choosing to do otherwise is at your own risk. For those interesting in learning the technique tea leaves are great for practice as I do not know of anywhere where either tea leaves or caffeine powder are illegal.
Please remember safety first and take two for safety before doing anything with chemicals ever. Always wear long sleeves and pants and shoes that cover the whole foot and proper lab attire when working with chemicals. Wear all appropriate personal protective equipment including but not limited to safety glasses, good gloves (in this case nitrile gloves that are at least 8mil thick are highly recommended, gauntlets are even better, check the chemical resistance of any gloves before using as sometimes they can be worse than nothing. A simple google search takes almost no time but can make a huge difference), and a proper mask or respirator if adequate ventilation is not available.
So first off what do we mean when we talk about extractions? Obviously for us it's always about getting some kind of active out of some type plant or fungus material. Generally these are done as either solvent extractions or acid base extractions. A solvent extraction involves washing or soaking the material with a solvent, typically a partially polar solvent like an alcohol, or a nonpolar solvent like ether or hexane, though water extractions are quite common, but I really hope you can handle that one by yourself, as it is literally as simple as making coffee. Examples would be making BHO or extracting cactus alkaloids and other nonpolar material to make cactus tar from a San Pedro with an alcohol. These are pretty straight forward and I'm not going to go into much detail. The variables are what kind of solvent you use, the length of time the extraction is done for and what temperature it is done at.
Acid base extractions are a way of extracting alkaloids based on their chemical properties and solubility. Alkaloids are naturally occurring compounds which contain a basic nitrogen group. Basic in this case refers to acids and bases, it means the N atom is able to accept an acidic proton. This gives alkaloids some interesting properties. The one we're most interested in here is it's solubility in various solvents. In their freebase (when the N is not protonated, or bonded to an additional hydrogen atom) form the alkaloids we're interested in are generally not water soluble, but are soluble in nonpolar solvents. The protonated form is water soluble owing to the fact that they form salts when they get protonated, for example a hydrochloride salt forms when hydrochloric acid is used on the alkaloid, the H atom binds to the N atom creating a positively charged molecule and the chloride ion binds to this because it has a negative charge. Both forms are usually soluble in alcohol because it is partially polar, but that same property makes alcohol dissolve lots of other stuff you don't really want.
Not all bases (or acids) are created equally though. And this is one of the properties that allow us to separate these alkaloids. In chemistry we measure the relative strength of acids and bases with a number called pKa. The lower the pKa the more acidic a substance is. To give you an idea of what this means a very strong acid will have a pKa of 1 or less, they will fully protonate water in solution. Compounds with higher pKa values are bad proton donors, but will be protonated pretty easily. For example mescaline has a pKa of 9.56. This means that in if you put a gram of mescaline into a solution with a pH of 9.56 50% of it would be protonated while the remaining half would remain as the freebase. Shifting by 1 point in either direction would make it 90/10, so at 8.56 90% would be protonated and 10% would remain as the freebase. Another point shifts it to 99/1. Going further doesn't really offer much benefit. When doing an extraction you want to get your pH about 2 points higher to do your extraction to get almost all of the alkaloid as freebase that you can collect with the solvent but at the same time keep the pH as low as possible to avoid forming an emulsion (a mixture of a nonpolar liquid and a polar one, like oil and vinegar in a salad dressing) that will take forever to separate.
The basic procedure is the same for all A/B extractions. First you want to put your material in an acidic solution (it only needs to be slightly acidic, a pH of <5 is generally sufficient) and extract with a nonpolar solvent to defat the solution (note, filter out your source material prior to separating, it makes it so much easier, then return it to the aqueous layer after separation each time). While this step isn't always strictly necessary it improves product purity and makes the work easier as it gets rid of many compounds that can cause the mix to emulsify at higher pH. It is essential when working with cacti. To extract you add a small amount of the nonpolar solvent (about 1/5 of the volume of the aqueous layer), and ideally you put them in a separatory funnel (a 500mL one costs like $25 and make extractions so much easier) and shake them up (invert it and turn the stopcock to vent it every 15 seconds or so) thoroughly. Then allow the mixture to separate and discard the nonpolar layer (if you have a still you can distill the NP solvent to recycle it, it's good for your wallet, the environment, and means you need to purchase solvents less frequently which can reduce risks to you).
Now you raise the pH of your aqueous layer to the pKa + 2 of your desired substance. You should see a (usually) white precipitate form (some chems are different colors but most of the ones we're interested in are white). Now extract again with the nonpolar solvent, then separate and save the NP layer and the aqueous layer. Soak your source material (MHRB, cacti, etc) in the aqueous layer some more (you will probably need to adjust your pH), give it at least 4 hours this time, then repeat the extraction again. Now do it again but let it go overnight this time. Extract again. Repeat again giving 12 hours or more and extract, then go one more time overnight. This is a total of 5 times over the course of 2 to 3 days which is my standard general procedure. As you get familiar with your source material you may find you want to do fewer pulls or more pulls.
Now pool your nonpolar layers and rinse them 3x with a small volume (depending on how much nonpolar solvent you have it could be anywhere between 10-50mL) of a concentrated brine solution with a pH of pKa + 2.5 (pH the water then add as much salt as it can dissolve). This pulls out any polar stuff that managed to hitch a ride and helps your purity.
Now we're ready to crystallize. Generally this is done by adding acid to form a salt. DMT doesn't like to form stable salts, but you can use fumaric acid to salt it out, otherwise reduce the volume of your nonpolar solution by 50-75% and stick it in the freezer overnight to get it to precipitate. For other stuff there's several ways to salt it out. The best method is bubbling dry hydrogen chloride gas through it. If you are using this document as a guide you probably don't have the skills to do that though. Dry HCl is nasty stuff that you really don't want to breathe in or have it come into contact with your mucous membranes. If you've ever opened a bottle of con HCl outside a fume hood while breathing in without a respirator you'll have a little taste of what this can be like. The dry gas is much much worse. I got a tiny tiny whiff once and I hacked up some vile looking shit. It probably wouldn't have looked as bad if I wasn't a smoker, but then I wouldn't be that surprised if the tars actually protected my lungs a bit.
So since dry HCl is out let's look at some other ways. Many light organic acids will be soluble in the nonpolar solution and will react with and precipitate your alkaloid. Fumaric acid mentioned above is one of these, another readily available one is glacial acetic acid. I like hydrochloride salts. They're generally quite stable over the long term, easy, and cheap to make from readily available substances, and are commonly the salt for which doses of a given substance are listed as. To make them without dry gas put about 0.25mL of con HCl in about 5-10mL of isopropanol that's at least 91%. Anhydrous is even better. (You can dry 91% IPA by adding dry epsom salts (bake at 250F+ for at least 1 hour) to it and letting them sit for a few minutes before filtering. You want to do this 2-3x to ensure the water has been absorbed. Leave some of the epsom salts in the liquid if you're storing it for any amount of time and filter them at the time of use). Now add this slowly to your nonpolar solution and watch beautiful white crystals start crashing out of solution. Filter off the crystals, and hit the solution again to see if anything else precipitates. Repeat until no more crystals form.
For the math lovers among you the 0.25mL of con HCl has about 3mmol of HCl, so it should precipitate ((molar mass of substance HCl/1000)*3)g of product per addition. If you're doing a larger scale extraction you can increase the amount of HCl used initially but keep it reasonably dilute (no more than maybe 1mL of HCl per 5mL IPA) to make sure it gets into the NP layer rather than forming a separate layer, shaking the solution after adding the HCl can help makes sure it all gets into contact with the product, but it's not as pretty to watch so try to get a good first crop anyway. Appreciate the beauty inherent in science.
So a step by step write up would look like this.
1. Place the substance you are extracting into an appropriately sized glass or stainless steel vessel. You want to be able to have your starting material completely submerged with an inch or so of water over it and have a few inches of room above it before the rim. You don't want any of this stuff spilling!
2. Make the water layer slightly acid. 3-5 should be just fine.
3. Put the starting material, water layer and nonpolar solvent (about 1/10-1/5 of the volume of water) in a sealable container (again glass or stainless steel just like everything else used in this tek) and shake the hell out of it. Vent it every 15 seconds or so to avoid a pressure build up.
4. Filter the source material out and then separate the liquid layers. Discard the nonpolar layer.
5. Put the source material and the aqueous layer back together and adjust the pH of the solution to the pKa of the desired product + 2
6. Allow to stand with stirring or other mixing agitation for 10 mins. Check pH, adjust if needed, mix for another 20 minutes.
7. Place in sealable vessel with nonpolar solvent (about the same volume as was used in the defatting step) and mix thoroughly, filter the starting material and separate. The source and aqueous layer go back together, save the nonpolar layer.
8. Readjust pH of aqueous layer if needed and allow to soak for 4 hours. Extract and separate again. Again recombine the aqueous layer and the source and save the nonpolar layer.
9. Do another 4 hour run on the source, and separate again. Then repeat twice waiting 12-24 hours to ensure you get all of teh desired product out.
10. Pool nonpolar layers and rinse 3x with a small volume of concentrated brine of pH=pKa+2.5. Save the nopolar layer.
11. Crystallize as above either by salting or freezer precipitation as discussed above.
Some notes. There are many suitable solvents. Heptane works very well for DMT because while it goes into solution quite well it can also be gotten out by concentrating and freezing. Xylene and d-limonene are both quite popular for mescaline. Caffeine isn't very picky about the nonpolar solvent. In general most things aren't, but look around to see if others have found an optimal solvent. Substitutions are generally ok. Try to stick to things that have fire diamond ratings of 3 or less for flammability, 1 or less for health, and 0 for reactivity for solvents.
