Researchers Say Chocolate Can Skew Cannabis Potency Test Results

People have been adding cannabis to food for hundreds, if not thousands of years, but magic brownies have become one of the more popular THC-infused edible snacks over the past several decades.

With the spread of legalization across many states in the U.S. and other countries, cannabis-infused brownies and chocolate candies remain popular edible products.

But when it comes to THC potency and contaminant testing, which is a common requirement in legal locales, new research indicates that chocolate can interfere with the process and produce inaccurate results.

Principal investigator David Dawson, Ph.D. and other colleagues from Oakland-based CW Analytical Laboratories will be presenting results from their current research at the American Chemical Society Fall 2019 National Meeting & Exposition in San Diego this week.

Dawson says that their research focuses on cannabis potency testing because of the high stakes associated with it.

In California, edibles that test 10 percent below a product’s listed THC content must be relabeled.

If an edible tests at 10 percent THC or higher, the entire batch must be destroyed.

The food that cannabis is infused with is referred to as a matrix, the composition of which can affect potency results.

Dawson and his colleagues decided to focus their research on cannabis chocolates because of how common they are.

Speaking anecdotally, Dawson said that the research team noticed weird potency variations depending on how they prepared the chocolate samples for testing.

To study the effects of altering sample prep condition on the concentration of delta 9 THC measured by high-performance liquid chromatography, the amounts of chocolate and solvent, and pH and type of chocolate were varied.

“When we had less cannabis-infused chocolate in the 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,” says Dawson. “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.”

Dawson says that changing how much of a sample is in the vial could determine whether a product passes testing and may have a potentially huge impact on the manufacturer or the consumer who could over or under-dose.

Results from Dawson’s research indicate that a component of chocolate is responsible for the matrix effects; he is now trying to discover which one it might be.

“Our best lead right now is that it has something to do with the fats,” says Dawson. “Which makes sense considering that delta 9 THC is fat-soluble.”

With the goal of contributing to the development of standard methods of cannabis potency testing for a variety of edibles, the research team is also looking to expand their analysis to other cannabinoids such as cannabidiol (CBD) and investigate other food matrices such as chocolate chip cookies.

One Response

  1. Howard Paris August 31, 2019