Stick to Vaping, to Be Safe

You’ve probably heard someone say that they don’t vape medical cannabis because it’s too imprecise, or too difficult to control their dose. However, edibles are not as precise as many patients think—especially if they are chocolate—thanks to the nature of cannabis potency testing.

Testing cannabis edibles for potency is already a challenge. That’s because even when you mix a known amount of THC into a known amount of other ingredients, the ratio of THC to everything else is so small that it’s not easy to get an even mix throughout the edible. The skill and accuracy of those extracting the THC in the first place can also vary.

Now, researchers have found that components in chocolate could interfere with cannabis potency testing and produce inaccurate results.

Chocolate Edibles, Cannabis Potency Testing, and “The Matrix”

“My research focuses on cannabis potency testing because of the high stakes associated with it,” project PI David Dawson, Ph.D., stated in a press release. “If an edible cannabis product tests 10 percent below the amount on the label, California law states that it must be relabeled, with considerable time and expense.”

The problem is more serious when a product tests 10 percent or more above the labeled amount. In those situations the entire batch must be destroyed.

The chemical composition or “matrix” of the foods added to cannabis edibles can affect potency testing results. Dawson and the team chose to focus on cannabis-infused chocolates because they are a popular kind of edible.

“We noticed, anecdotally, some weird potency variations depending on how we prepared chocolate samples for testing,” Dawson noted in the press release. This led the team to measure how different ways of prepping samples changed concentrations of Δ9-tetrahydrocannabinol (Δ9-THC), the major psychoactive constituent of cannabis, using high-performance liquid chromatography (HPLC).

For example, they altered type of chocolate, pH, and amounts of chocolate and solvent—with surprising results.

“When we had less cannabis-infused chocolate in the sample vial, say 1 gram, we got higher THC potencies and more precise values than when we had 2 grams of the same infused chocolate in the vial,” Dawson continued in the press release. “This goes against what I would consider basic statistical representation of samples, where one would assume that the more sample you have, the more representative it is of the whole.”

Keep Calm and Vape On

The findings indicate some other matrix effect in the chocolate was suppressing the Δ9-THC signal. In other words, this effect could make any given sample too strong or weak to represent the batch, rendering cannabis potency testing protocols ineffective.

“Simply changing how much sample is in the vial could determine whether a sample passes or fails, which could have a huge impact on the producer of the chocolate bars, as well as the customer who might be under- or overdosing because of this weird quirk of matrix effects,” Dawson added in the press release.

The team is working to tease out which components of chocolate might be involved in this effect, and which other cannabinoids might be implicated. As yet, they have not found any connection to this cannabis potency testing issue and vaping products.