hmp1

11.1.3 Agent Lemon: Dual-Phase Acid-Base Extraction of DXM

(Note: This first page is probably all mumbo jumbo to anyone without Chemistry experience. Read the first page anyway to get a better understanding, and the second page is much easier to comprehend. It tells you how to do it in layman's terms.)

The Mission: extract DXM from cough syrups with materials and equipment that one could buy without any trouble at your nearest Walmart.
Theory:
The DXM FAQ [1] describes an acid-base extraction method that requires materials (specifically Sodium Hydroxide) that are difficult to get in pure form for many people. Read it for the theory. Now, after you read it, we'll add on the following:
The "acid-base" extraction in the FAQ does not actually use an acid stage. We can add an acid stage, to remove the DXM from the solvent. Therefore, we can avoid the need to evaporate a lot of solvent -- we can just throw it out the drain. Thus, you can do this without producing vapors that will lead your neighbors to think you are running a meth lab.
The Materials: (this will blow you away)
DXM-containing cough syrup. This process will probably produce a dangerous product if you use a syrup that contains any active ingredients other than DXM or Guaifenesin. DON'T! We used Robo Max Cough because CVS was closed.
Ordinary Household ammmonia (clear, not lemon or some other scent)
Lighter Fluid (we used "Zippo"; check criteria in FAQ [1]). Make sure it evaporates with no residue.
Citric Acid. Available as a canning supply at your neighborhood supermarket. We used lemon juice on the first attempt, but we switched to citric acid after consultations ([1], personal communication).
Equipment:
[A brief interjection here. This paper suggests using a siphon to separate the layers. However, I think the plastic baggie separatory funnel is a superior method, for two reasons. First, rubber tubing (and many types of plastic) are attacked by organic solvents, and can degenerate, or (worse) dissolve into the solvent and possibly muck up the extraction. Second, you get much better control with a separatory funnel, even a kitchen chemistry version. I will follow up their method with my suggestion. (The ziploc baggie separatory funnel is very easy to do. Simply pour solution into a large ziploc baggie, and seal, then let the mixture seperate and cut off the bottom corner of the baggie. Let the bottom layer drain out. The pinch the corner to stop the flow. You have seperated the two layers of the mixture.)
Some containers and flexible rubber tubing to use as a siphon. We cut ours off our vaporizer because we don't know where we stashed the tubing.
Two large zipper-seal (e.g., Zip-LockTM) plastic freezer bags, unpleated (if you want to use the separatory funnel concept instead of the siphon).
Concept:
Prepare ahead of time a solution of the citric acid in water. For two bottles of tussin (8 oz each) we used 3 tablespoons of citric acid in 8 fluid ounces of water.
Add ammonia to DXM. DXM converts from hydrobromide salt to freebase and precipitates out of water. Since it is now nonpolar it wants to go into a non polar solvent. Now you add a nonpolar solvent and shake hard. Free base goes into solution in solvent. Let solvent float to the top. (doesn't mix with water) Physically separate the layers. Now the DXM is in the nonpolar layer, mix that with the acid and shake well. The DXM converts back into the acid salt (since lemon juice has citric acid in it, we make DXM hydrocitrate). This is so beautiful because the DXM is practically pulled across the oil-water interface by the hydrogen ion gradient.
Now you throw out the oil layer, and the DXM is now acid salt in the lemon juice. Boil it for a few minutes in the microwave, stir it good, so any volatile solvent that remains will evaporate.
You are left with "Agent Lemon" or "DXemon juice", a highly concentrated product, which is superior to cough syrup -- if you really wanted to, you could probably boil away the water -- with no danger, since the amount of solvent is almost nothing, and get a crystalline product that might be cut with anhydrous citric acid. I wouldn't suggest it, since it might irritate the stomach. (continued on page 2)