Katherine Biggie, a graduate student from Bowling Green State University, has published an excellent thesis entitled “CANNABIDIOL EXTRACTION AND QUANTIFICATION: A COMPARISON OF FOUR SOLVENT BASED EXTRACTION METHODS IN GUMMY MATRICES.” Four extraction methods were compared to determine the ideal method to use with a gummy matrix. The four methods are acetonitrile soak, QuEChERS followed by SPE clean-up, the USDA method, and the Virginia Department of Forensic Science method.
Of the four extraction methods tested, it wasn’t surprising that QuEChERS provided the highest percent yield. The USDA method’s percent yield was less than the QuEChERS technique, and the acetonitrile soak, and the Virginia methods did not supply any yield.
Here is a summary of the QuEChERS method used.
- Add 10 mL of water to a cryo-ground gummy in a 50 mL centrifuge tube.
- Hydrate for 30 minutes with occasional vortexing.
- Add 10 mL of acetonitrile to the tube.
- Vortex the tube for one minute.
- Add the salts from QuEChERS packet ECQUEU750CT-MP from UCT (4g anhydrous magnesium sulfate, 1g NaCl, 0.5g Na2HCitr.1.5H2O, 1g Na3Citr.2H2O).
- Immediately cap and shake for 1 minute.
- Centrifuge for 5 minutes.
- Add 1 mL of the supernatant to a 15 mL tube and dilute 10x using the pH 7 buffer solution prepared from UCT part SPHPHO7001-5 (containing 100 mM powder added to 1 L. of water).
- Prerinse the UCT extraction cartridge CSTHC206 – Clean Screen® THC extraction column, 200mg/6mL, with 3 mL of 1:1 hexane: ethyl acetate.
- Soak for 1 minute and drain to waste by gravity.
- Condition the sorbent using 3 mL of methanol.
- Drain the methanol by gravity until the meniscus touches the top fruit. From this point, do not allow the cartridge to dry.
- Equilibrate the sorbent using 3 mL of the pH 7 buffer solution.
- Drain the buffer solution by gravity until the meniscus touches the top fruit.
- Add the 15 mL of QuEChERS extract to the cartridge and allow the extract to drip through the cartridge by gravity.
- Rinse the 15 mL tube with water and add it to your eluting sample.
- Continue to drain everything to waste by gravity.
- Once all the sample and water have passed through the cartridge, apply vacuum pressure to the cartridge for 1 minute.
- Add 3 mL of hexane to the 15 mL tube as a final rinse and add this rinsate to the cartridge, and drain under slight vacuum pressure for 5 minutes to waste.
- Pull full vacuum pressure on the cartridge for 5 minutes to dry the sorbent.
- Insert a collection rack with test tubes under the cartridge and elute the cartridge with 3 x 1.5 mL of 1:1 hexane: ethyl acetate by gravity and collect the eluate.
- Evaporate the eluate to dryness at 50C and reconstitute in isopropanol.
Extractions and Yields of the 4 Methods**
** Biggie, K. (2023). Cannabidiol Extraction and Quantification: A Comparison of Four Solvent Based Extraction Methods in Gummy Matrices [Master’s thesis, Bowling Green State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1678900891589169
UCT Application Note: Extraction of Cannabinoids in Marijuana and Edibles by QuEChERS