Deeper Dive into Extractions: Multiphase CO2 Extractions for Full Spectrum Native Chemical Profiles

October 24, 2019
Abstract / Synopsis: 

This series of guest columns from Amber Wise and various coauthors has covered a general overview of the most common extraction solvent systems and the importance of companies respecting the whole plant molecular profile in their formulations. In this final installment, we review more nuanced methods for retaining native chemical profiles for terpenes and cannabinoids for full entourage effect formulations. This column gives an overview of some of the ways various temperature and pressure combinations can tune the polarity of CO2, and how analytics can be utilized to monitor chemovar profiles. It will finish by reviewing some ways companies are utilizing multiphase extraction (MPE) to their advantage in formulations.

This column series over the past year has covered a general overview of the most common extraction solvent systems (1) and the importance of companies respecting the whole plant molecular profile in their formulations (2). In this final installment, we review more nuanced methods for retaining native chemical profiles also known as chemovars for inhalation extracts via multiphase CO2 extraction (MPE) and how the methods apply in the most mature cannabis marketplace in the world.

Carbon dioxide as a solvent for natural products is not new and has been used extensively (3) to extract a wide variety of plant-derived compounds (4) such as terpenes, fats, and lipids (5). The cannabis industry has capitalized on the tuneable properties of CO2 and its ability to be a very flexible solvent for a wide variety of molecules.

In 2012, Washington state was the first state in the nation alongside Colorado to legalize recreational cannabis. It is considered by many to be the most mature, legal cannabis marketplace in the world. It is highly competitive with more than 20,000 individual stock keeping units (SKU’s) or products for sale, of which the majority are comprised of some sort of extract. Washington state is often looked at as a case study for extraction technology because of the concentration of talent and extraction equipment manufacturers in the region. This gives the Pacific Northwest a unique position to be on the cutting edge of CO2 extraction. In fact, the MPE method discussed in this column was developed there.

Multiphase CO2 extraction is an award-winning method that is designed to preserve the full spectrum of cannabinoids and terpenoids, while minimizing chemovar drift. Chemovar drift is any deviation in a final extract from the native, input material’s (cannabis flower) chemical profile. Baseline chromatograms are created by analyzing the input material for cannabinoids and terpenoids. Chemovar characterization analytics are performed by a third party laboratory (such as Confidence Analytics Labs) in Washington state using a Shimadzu high performance liquid chromatography (HPLC) system for cannabinoid characterization and an Agilent gas chromatography–mass spectrometry (GC–MS) system for terpenes. By applying the same methods to the finished extract and assessing the deviation between the samples, the concept of chemovar drift is better understood.  See Figure 1 for a comparison of the input flower material, the raw extract, and the purified terpene profile overlaid to show the similarities between ratios and molecular profiles.

Figure 1


The cannabis matrix is complex with hundreds of active compounds with various molecular properties and polarities. There are a wide array of standard chemical solvents that are useful in capturing most of them. However, when choosing an extraction solvent for inhalation products, human consumption and safety needs to be considered and the list of solvents that are easily removed in the finished product for safe human consumption is shortened dramatically. As the increase in lung illnesses in consumers of e-cigarettes and illegal cannabis vape cartridges grows, it’s important to understand that cutting agents, diluents, and other noncannabis components are unnecessary for formulations. The MPE method discussed here is designed for the commercial production of full-spectrum, inhalation extracts.  It takes into account all the key factors of regulatory, safety, sensory, efficacy, and scalability that are required for viability in the increasingly-competitive cannabis industry.

  1. A. Wise, Cannabis Science and Technology 2(1), 20–26 (2019).
  2. A. Wise and A.C. Braddock, Cannabis Science and Technology 2(3), 16–20 (2019).
  3. M.B. King and T.R. Bott, Extraction of Natural Products Using Near-Critical Solvents, (Chapman & Hall, 1993).
  4. B.A.S Machado, et al., Sep. Sci. Technol. 48(18), 2741–2760. (2013). 
  5. F. Sahena, et al., J. Food Eng. 95(2), 240–253 (2009).

About the Guest Columnists

Amber WiseDr. Amber Wise is currently the Science Director at Medicine Creek Analytics, a certified cannabis testing laboratory in Washington state. She was previously the Science Director at Avitas, a licensed cannabis grower and processor in Washington and Oregon. Direct correspondence to: [email protected].


Randy ReedRandy Reed is the CSO at Fractal Labs in Washington state. He is an award-winning cannabis scientist, winning “Best drink” in 2017 and 2018 WA Dope Cup, “Best THC cartridge” in 2018 WA Sun Cup among 12 other first-place finishes across multiple categories. Randy is known for his novel and patent-pending work in CO2 extraction and cannabis beverages via his IG account @Marlin_Rando, where he’s posted the world’s first CO2 Live Resin extracts as well as the world’s first Cannabis Terpene beverages. He holds a BA in Interdisciplinary Arts and Sciences from the University of Washington and is an active member in Canna STEM, NCIB, and WSIA.

How to Cite This Article

R. Reed and A. Wise, Cannabis Science and Technology 2(5), 14-19 (2019).