Polar /Non Polar Extraction.
Some of our readers have shown interest in isolating the acidic from the neutral cannabinoids. So I set out to nail down a DIY capable procedure for the masses. The cannabinoids are first produced by the plant in their carboxylic acid form and over time these compounds are reduced to their active phenolic form. There is some evidence suggesting the medicinal benefits of the acidic compounds may be different than the phenolic compounds. This procedure will isolate the carboxylic acid compounds from the phenolic compounds. Keep in mind that heat, UV light and reactive oxygen species will reduce the carboxylic acids to their phenolic form.
Note: All or almost all of these items can be picked up locally or on Ebay. Be sure to always look at compatibility charts for anything not made from quartz or borosilicate glass.
- Glass or other chemical resistant funnel
- Glass beads size #13 (used for sandblasting)
- Glass container(s) (as many as you need for extracting)
- 3) 500 mL Erlenmeyer flasks (or quart mason jars)
- 3) Pasteur pipets or glass droppers
- 3) Glass 4oz bottles with droppers
- Glass stir rod
- Glass or other chemical resistant 250 mL graduated cylinder
- Oil bath
- PH paper (1-12)
- Balance or scale capable of weighing 0.1g
- Nitrile gloves
- Safety Glasses
- Coffee filter
- Hair dryer
- Ice bath
- 100 mL 0.1M sodium hydroxide (NaOH) Food Grade
1M = 40g/L 0.1M = 4g/L or 0.4g/100 mL (This solution is made by adding NaOH to a 50 ml of water, slowly while in the ice bath, then bringing to the final volume)
- 100 ml 32% hydrochloric acid (HCL)
- 100 ml 1% HCL
(This solution is made by adding 60 drops down the inside of the glass into 97 ml H2O) ($5 for 500 mL of 32% on ebay)
- ACS grade n-Hexane 3L /50g flowers for extraction
~250 mL for washing sand filter ~100 mL for NP extract from sand filter (~$18/L on ebay, always buy a little more than needed)
- Denatured or isopropanol alcohol
- 1 gallon distilled water
- 10g Kosher salt (add to the water)
Note about safety: Always read through the procedure twice before you gather your chemicals and supplies. Make all your solutions label them with the chemical, concentration and the date they were prepared and set aside. I can’t stress labeling enough and not just for your sake. Check off each step as you go along in case you are interrupted or have a stoner moment. Move slowly and deliberately to avoid accidents. Don’t forget to wear proper safety equipment. When working with acids and bases it’s always advisable to keep a baking soda and water solution to neutralize any acid spills or splatters and a mild vinegar solution to neutralize any base spills. Kitty litter has saved my hide and I suggest you keep some handy.
Note on acids: Always add acid to water; never the reverse. Always drop down the side of the container so that it runs down the glass. When washing the sand filter with acid get as close to the beads as possible to avoid splatter. While uncomfortable 32% HCL not immediately scar your skin; you ll know immediately that it’s on you, but don’t panic. Baking soda is your first choice then flush the area for 15 min with running water. If it’s in your eyes flush immediately with water holding your eyelids away from your eyeballs. 15 min is an eternity when you are under the water and more is better in this instance.
Overview: This procedure can be used with fresh material if you want mostly carboxylic compounds. If you are using fresh material finely scissor chopped is sufficient. The longer the material is exposed to the hexane the better your yield will be. Decant the hexane through a strainer to catch any particulates. Hexane boils below any significant decarboxylation temperature; so there is no reason to worry about any unintentional conversion when reducing the extract. The reduced extract should be easily dropped but still thick.
The sand filter is elegantly simple in its purpose. The glass beads provide a surface to dry the extract and because they are wet with H2O when you apply the hexane extract will remain on the surface. The glass beads need to be washed with all those chemicals in series to remove any impurities that would co extract if you didn’t. It is very important that the sand filter is wet when you apply the extract so moisten if necessary.
The polar extraction from the sand filter will remove few impurities and will be the highest quality of all the extracts. The color change from orange to clear is a convenient indicator that you are finished and can move the filter to the semi polar collection container. The semi polar extraction will be the dirtiest of the extracts. Most people don’t like to waste their hard work and this extract is still worth using. The alcohol also helps to wash away the impurities that would otherwise end up in your non polar extract. After washing the filter clean with hexane in the non-polar extraction the filter needs to dry completely. While the sand filter is drying proceed with acidifying the polar extract to a PH of about 2 then filter. Neutralize and discard the flow through then re extract the filter with alcohol. Reduce the extracts until dry and polish as you like. See our polishing extracts page for more info.
- Grind thoroughly dried and de-stemmed flowers and sift out any woody material.
- Place material into a large glass container(s)
- Add 1L of n-Hexane per 50g material
- Mix well
- Let stand several hours
- Decant n-Hexane and retain
- Repeat steps 3-6 two more times
- While Hexane is extracting prepare the sand filter
- Place the coffee filter into the funnel folded over without wrinkles
- Fill funnel 2/3 of the way with glass beads
- Wash with hexane
- Wash with alcohol
- Wash drop wise with 1% HCL ( if you see bubbles keep washing)
- Rinse thoroughly with distilled water 3 to 4 funnel volumes
- Set aside
- Combine and reduce hexane extracts in the oil bath to a thick resin
- Note: Hexane can expand rapidly (3 times the liquid volume or more) when heated without constant stirring.
- Re wet sand filter with H2O
- Drop wise place hexane onto the center of the sand filter while drying with the hairdryer
- Label the 500 mL Erlenmeyer flasks (or quart mason jars)
- Semi Polar
- Non Polar
- Drop wise extract with your 0.1M NaOH until the liquid turns from deep orange to colorless. Rinse with H2O
- In an ice bath: Acidify the extract with 32% HCL drop wise on the glass
- Semi Polar: Rinse sand filter with 200 ml Alcohol
- Non Polar: Rinse with hexane until colorless
- Filter the Polar extract after the sand filter dries.
- Neutralize the polar junk that’s left with 0.1M NaOH and dispose
- Then extract with alcohol into a clean container
- Reduce all extracts
- Polish each as you like and enjoy
We will update this page with pictures in the future.