Medical marijuana generally possesses high levels of the psychotropic tetrahydrocannabinol (Δ9-THC) and lower levels of the nonpsychotropic can nabidiol (CBD). Pain mitigation and reduced severity of nausea and seizures are just a few of the therapeutic benefits reported by medical cannabis patients. The main source of CBD-rich oil is carbon dioxide or butane extraction of industrial hemp. Hemp is a robust crop containing high quantities of CBD and minor quantities of other cannabinoids. Like cannabis, hemp oil may be analyzed easily and effectively for its cannabinoid content. Presented herein is a procedure for the quantitative determination of 11 important cannabinoids, including CBD, in hemp oil using high performance liquid chromatography (HPLC) with ultraviolet (UV) detection.
Medical marijuana generally possesses high levels of the psychotropic tetrahydrocannabinol (Δ9-THC) and lower levels of the nonpsychotropic cannabidiol (CBD). Pain mitigation and reduced severity of nausea and seizures are just a few of the therapeutic benefits reported by medical cannabis patients. Conversely, hemp contains high levels of CBD and lower levels (generally less than 0.3%) of THC. CBD has been reported to reduce or eliminate pain, stress, depression, inflammation, and headaches.
To complicate matters, there is evidence that a combination of CBD, a host of other minor cannabinoids, and a complex array of terpenoids may provide the most benefit—called the entourage effect (1). Both free and esterified sterols and triterpenes have been identified in cannabis and hemp, among which β-sitosterol and β-amyrin have been shown to have antibacterial properties (2). CBD-rich oil has become increasingly popular and is administered via sublingual drops, gel capsules, or as a topical ointment.
The main source of CBD-rich oil is industrial hemp. Hemp is considered a rustic plant because it is frost resistant, adapts to poor soil, reproduces easily, and does not require chemical fertilizers, pesticides, herbicides, or fungicides to thrive. A hemp crop tends to resist mildew and requires less water than cotton. Hemp textiles are considered softer than cotton.
CBD oil is derived as concentrate from carbon dioxide or butane extraction of hemp, sometimes followed by steam distillation or ethanol distillation for purification. The Farm Bill of 2014 distinguishes hemp from marijuana, yet interpreting the law is difficult in that “CBD oil” may be classified as marijuana. Various forms of hemp oil may be purchased online.
The U.S. Food and Drug Administration (FDA) has issued warning letters against unproven claims to some companies that market products containing CBD. As part of these actions, the FDA has determined the cannabinoid content of some hemp products and many were found to contain levels of CBD that are very different from the label claim. It is important to note that such products are not approved by the FDA for the diagnosis, cure, mitigation, treatment, or prevention of any disease (3).
The literature indicates more than 90 phytocannabinoids in cannabis and hemp (4). Only a handful are common targets of analysis for medical potency because they are the most abundant. Like cannabis, hemp oil may be analyzed easily and effectively for its cannabinoid content. This work presents the quantitative determination of 11 important cannabinoids, including the predominate CBD (Figure 1), in various hemp oils. (See upper right for Figure 1, click to enlarge; Figure 1: Cannabinoids found in hemp and marijuana.)
Using a comprehensive mixture of 11 cannabinoids (Shimadzu Part #220-91239-21; 250 µg/mL), standard curves were prepared for each target analyte with a minimum acceptable correlation coefficient (R2) of 0.999 over six standard levels. A linear dynamic range was established at 0.5–100 mg/L (ppm) in each analyte.
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- C.M. Andre, J.F. Hausman, and G. Guerriero, “Cannabis Sativa: the Plant of the Thousand and One Molecules,” Frontiers in plant science, frontiersin.org (2016).
- US Food and Drug Administration, Warning Letters: https://www.fda.gov/newsevents/publichealthfocus/ucm484109.htm (FDA, Rockville, Maryland).
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Craig Young, MS, is the HPLC product manager for Shimadzu Scientific Instruments in Columbia, Maryland. Bob Clifford, PhD, is the general manager for Shimadzu Scientific Instruments. Direct correspondence to: [email protected]
How to Cite This Article
C. Young and B. Clifford, Cannabis Science and Technology 1(2), 38-43 (2018).