6.24.2018

Straight to Solvent (STS) Alkaloid extraction method

A straight alkaloid extraction to solvent that includes a few simple steps like acidifying, basifying and salting.  No special glassware or tools are needed but a glass mortar and pestle, coffee grinder, glass bottles, dropper bottles, glass funnels, beakers, crystallization dish, and vacuum evaporation setup is desired.  It is similar to drytek and Straight to Base (STB) and also Acid Base (A/B) extraction.  The benefits are likely higher alkaloid yield over AB and STB and also easier and less finicky than drytek.  Most similar to Q21Q21's Vinegar/Lime A/B Extraction Tek.

1. add herb to glass mortar and pestle.
2. grind herb to powder with or without liquid (skip if used coffee grinder).
3. add just enough water or vinegar to moisten the powder to a paste that flows well and allows easy mixing in the mortar and pestle. mix & grind (m&g).
4. add some acetic acid (excess is fine) if not using vinegar. m&g for a few mins only.
5. add some sodium carbonate or CaOH (or any other base, depends on your solvent choice and alkaloids) to desired pH.  Your pH should be 1-2 points higher than the pka of your alkaloid.  Overshooting the amount is fine. mind the temperature, try not to let it get too hot. m&g for a few mins only.
6. add decent amount of non iodized NaCl or other salts (including more sodium carbonate, magnesium sulfate, etc.) to increase ionic strength and dry the mix. m&g.  make sure pH is still at desired level.
7. add non polar solvent (nps) like limonene.  Use a small amount and m&g well.  Decant and collect the solvent for later.  Add more nps, m&g, collect solvent and keep repeating this until the solvent is clear.  Discard plant material and keep all collected solvent.
8. Add some magnesium sulfate (epsom salt) to the solvent, shake, then our solvent off into another container.  This will remove any water/cloudiness from the solvent.  Different solvents may require different drying agents like calcium sulfate.
8. Evaporate solvent.
if you are using limonene I suggest getting a ground glass flask with a vacuum elbow ground glass attachment and using a vacuum pump to help it evaporate faster.  Boiling chips can be added to limonene and will be helpful to prevent splashing and product loss. You can even collect the evaporated limonene if you want, look up vacuum distillation setups.  Make a 47-60c waterbath and put the flask with limonene in it.  This is right around the boiling point (but preferably you will not see much boiling) of limonene at the pressure of a decent vacuum pump.  Direct a fan blowing on the vacuum pump to help keep it cool.
9. If you want alkaloids to remain in solvent, redissolve with a little solvent and pour into dropper bottle.  If not, keep the crude obtained after evaporating.
10. If you want crystals you have 2 options.  If your alkaloids' freebase is a powder and your alkaloid is not super soluble in your solvent, then you can recrystallize in the concentrated solvent.  Otherwise just evaporate the solvent completely or go to step 11.  Preferably put your solvent in a recrystallization dish and put it covered in the freezer for a day or three.  Carefully and quickly (so it stays very cold) decant and discard the solvent keeping the crystals.  If it warms up at all when you are decanting then your crystals will redissolve and we don't want that.  Now evaporate the dish containing the crystals to dryness.  If you want to further purify the crystals, you can add a little bit of new solvent to redissolve the crystals (you can warm it up a bit so it redissolves easier) and recrystallize again.  If you just want to wash the crystals then make sure the crystals and dish they are in is frozen temp and a little extra new solvent is frozen temp too.  Pour the new solvent on the crystals and decant keeping the crystals and discarding the solvent. Then if you want water soluble crystals dissolve crystals in a little water and fumaric acid (see below for more info on acids) and evaporate the water using gentle heat.  Perhaps acidified ethanol would also work and evaporate easier.  These crystals can also dissolve in glycerine.
11.  If your alkaloid is an oil and you want crystals you will need to salt it out.  To do this take your concentrated alkaloid in solvent mix and add it to a bottle.  Now add some water with fumaric acid (or any other acid like tartaric, citric, vinegar/acetic, lactic, even hcl, depending on your alkaloids and how solid you want the final product).  For oily alkaloids use fumaric acid because it is non-hydroscopic so your powder/crystals will be drier.  Now mix this (can be just shaken in the bottle) and your alkaloids should come out of the solvent and into the acidic water.  This water can be evaporated and the crystals obtained.  These crystals will be soluble in water and/or glycerine.

notes:
-you can make sodium carbonate by baking baking soda in the oven.
-mortar and pestle is optional but I think it is the best mixing device for this process.
-caoh used for high pka alkaloids (10 or higher), sodium or potassium carbonate for low ones (around 9 or lower).  Sodium or potassium hydroxide can be used instead but mix it in some water before adding.
-vinegar added first to help break the alkaloids free from oxalic acid in the plant.
-want to add base before salting so all of the acetate salt can be converted to freebase.

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