The unique smell and effects of your favorite cannabis are largely determined by terpenes. With marijuana becoming legal in many places, the cannabis industry has evolved. Today, customers look for specific terpene profiles, not just THC and CBD. This has increased the demand for terpene testing in labs.
What is terpene analysis?
Terpene analysis involves measuring the amount of terpenes in a sample. This is essential for determining the sensory and therapeutic properties of plants, especially Cannabis sativa. Terpenes, along with the other compounds produced by the plant, may work together to create specific effects in cannabis (the entourage effect), so knowing which compounds are in use is important. This makes terpene testing increasingly popular in labs.
What are terpenes and how are they classified?
Terpenes are organic compounds that contribute to the aroma and flavor of many plants [1], including C. sativa. They also form the basis of essential oils used in food and cosmetics [2], for example. Terpenes may have therapeutic properties, such as anti-inflammatory, anti-cancer, and pain-relieving effects [3-8]. In C. sativa, terpenes affect both the sensory qualities of the buds and their therapeutic properties. Terpenes are made from combinations of isoprene units, which are molecules with five carbon atoms (C5). Terpene classification depends on the number of carbon atoms: monoterpenes (C10), sesquiterpenes (C15), and diterpenes (C20) [1].
How does terpene analysis help in cannabis quality control?
A high-quality cannabis sample should have a variety of terpenes. If the terpenes’ aroma is missing, the sample might be old or poorly grown.
Terpenes in Cannabis sativa
Cannabis sativa has a wide variety of terpenes. Around 150-200 terpenes have been reported, mostly monoterpenes and sesquiterpenes [2, 9]. Common terpenes in cannabis found in dispensaries in the U.S. include beta-myrcene, limonene, and beta-caryophyllene [10].
Importance of Terpenes in Cannabis sativa
Terpenes play a key role in the smoking experience by providing distinct aromas and potential effects. They interact with cannabinoids, enhancing their effects, and can also work with other terpenes in the plant. This is known as the entourage effect, which increases the therapeutic benefits of cannabis. For example, sativa strains are known for energizing effects and may contain terpenes like limonene and pinene, which have citrusy, fresh smells. Indica strains are associated with relaxing effects and may contain more myrcene, which has an earthy scent.
Methods of Terpene Analysis
The most common method for measuring terpenes is gas chromatography, often combined with mass spectrometry for more accurate results. Other methods include SPME and VASE. Gas chromatography is preferred due to the high volatility of terpenes.
Gas Chromatography: The Most Common Method
Gas chromatography (GC) is widely used for terpene analysis. It involves heating the sample and using an inert gas as the mobile phase to carry the sample through a column, where components are separated at different speeds. These components are detected and analyzed by a computer, and the data is displayed as a chromatogram.
Mass Spectrometry (MS): Finding the Molecular Weight of Cannabinoids
Mass spectrometry (MS) is a technique that separates tiny particles like atoms and molecules by looking at their charge-to-mass ratio. This method is used to measure the weight of particles. It works by analyzing the relationship between a molecule’s mass and its electric charge (m/z) in a sample.
This technique helps determine the exact molecular weight of different substances in a sample. Mass spectrometry can identify unknown compounds by measuring their weight. It is also useful for measuring the amount of known compounds and figuring out the structure of different molecules.
GC-MS Technique: Improving Accuracy in Terpene Testing
A commonly used technique for analyzing terpenes is gas chromatography combined with mass spectrometry (GC-MS).
Gas chromatography (GC) helps separate the different substances in a sample, while mass spectrometry (MS) identifies and measures each component. This combination is highly accurate for detecting both cannabinoids and terpenes. After GC separates the terpenes, MS fragments and analyzes them, providing extra details to confirm their identity. By using GC-MS, the type and amount of terpenes in a sample can be precisely measured.
Alternatives to Gas Chromatography: HS-SPME and VASE
Other techniques, like headspace solid-phase microextraction (HS-SPME), avoid using solvents and are suitable for volatile samples [2]. VASE uses a sorbent exposed to the plant’s flower for extraction, heated at a specific pressure and temperature.
Important Considerations in Terpene Evaluation
Standardizing testing methods and extraction protocols is important. Heating flowers too much before analysis can degrade or evaporate terpenes, altering the results.
Homemade Terpene Extraction
Olive oil is a good solvent for extracting terpenes, as it prevents them from evaporating. To make a terpene-rich cannabis oil, grind the cannabis, mix it with olive oil, and heat the mixture in a water bath.
Mysteries of Terpenes in Cannabis sativa
The reason why C. sativa produces so many terpenes is still not fully understood, but it seems these compounds act as a defense mechanism. Plants grown outdoors may produce more terpenes than those grown indoors, and the expression of terpenes can vary depending on environmental conditions.
I hope this helps with your terpene extractions using olive oil! Let me know how it goes!
- Micalizzi, G., et al., Cannabis Sativa L.: A comprehensive review on the analytical methodologies for cannabinoids and terpenes characterization. Journal of Chromatography A, 2021. 1637: p. 461864.
- Bakro, F., et al., Simultaneous determination of terpenes and cannabidiol in hemp (Cannabis sativa L.) by fast gas chromatography with flame ionization detection. Journal of Separation Science, 2020. 43(14): p. 2817-2826.
- Cox-Georgian, D., et al., Therapeutic and medicinal uses of terpenes, in Medicinal Plants. 2019, Springer. p. 333-359.
- Kamatou, G.P. and A.M. Viljoen, Linalool–A review of a biologically active compound of commercial importance. Natural product communications, 2008. 3(7): p. 1934578X0800300727.
- Rogerio, A.P., et al., Preventive and therapeutic anti‐inflammatory properties of the sesquiterpene α‐humulene in experimental airways allergic inflammation. British Journal of Pharmacology, 2009. 158(4): p. 1074-1087.
- Chaves, J.S., et al., Pharmacokinetics and tissue distribution of the sesquiterpene α-humulene in mice. Planta medica, 2008. 74(14): p. 1678-1683.
- dos Santos, É.R., et al., Linalool as a Therapeutic and Medicinal Tool in Depression Treatment: A Review. Current Neuropharmacology, 2022. 20(6): p. 1073-1092.
- Salehi, B., et al., Therapeutic potential of α-and β-pinene: A miracle gift of nature. Biomolecules, 2019. 9(11): p. 738.
- Radwan, M.M., et al., Cannabinoids, phenolics, terpenes and alkaloids of cannabis. Molecules, 2021. 26(9): p. 2774.
- Smith, C.J., et al., The phytochemical diversity of commercial cannabis in the United States. PLoS one, 2022. 17(5): p. e0267498.
