Mike May | Analytical Cannabis | June 27, 2017
The cannabis-testing industry — which is responsible for testing products for pesticides, potency and more — could use some help. Lack of standards, regulatory oversight and consumer awareness create market conditions where price, not quality, is the primary consideration when companies choose a testing lab. Unfortunately for consumers, there is no end to the corners a laboratory can cut. As the cannabis industry as a whole looks for legitimacy, it can follow other examples of testing, such as those used in the food industry.
Lab Director Vu Lam and Vice President Zach Eisenberg of Anresco Laboratories, one of the premiere pesticide screening labs in the nation, teamed up to talk about what the cannabis-testing industry can learn from the food industry.
“There is not really much difference between food and cannabis testing in terms of general methodology or instrumentation,” they note. “In fact, most of the cannabis products we test are just infused foods.” So, testing a cannabis-infused food for pesticides is similar to testing any other food.
Various tests on cannabis are also similar techniques. “When running a cannabis sample for pesticides, residual solvents or microbiology, we use the same procedures,” Lam and Eisenberg note. “We just make some modifications depending on the sample matrix.”
Managing mold
If we see mold on the outside of a loaf of bread, we just throw it out, but testing for mold in cannabis gets far more complicated. “Dried cannabis usually has moisture content of 10–12%,” says Bob Clifford, General Manager, marketing at Shimadzu Scientific Instruments. “Anything above 12% is prone to mold growth.”
That mold can create mycotoxins, and regulatory bodies restrict the levels of these molecules in food. “Reviewing these regulations is a good starting point,” Clifford says. Then, a lab can use high-performance liquid chromatography (HPLC) or LC followed by tandem mass spectrometry (LC-MS/MS) to test for mycotoxins.
As this example shows, some instrument companies with deep experience in food-industry applications provide platforms and knowledge that can be adjusted — often easily — to testing cannabis.
Facing financial limitations
“The expectations of customers are completely out of line with what they are willing to pay,” Lam and Eisenberg explain. “For example, if we perform potency testing of a pharmaceutical product based on USP or AOAC standards, we would analyze the sample in triplicate with triplicate injections to get an analytical error [that is a maximum of 1–2%].” That costs $500–1,000 per sample depending on what the client wants. But, as Lam and Eisenberg point out, cannabis clients often want top-notch testing on a shoestring budget.
“For cannabis testing, the market conditions are such that we can only charge $75 per sample for a potency determination,” Lam and Eisenberg said, noting that the smaller fee only buys a single extraction run at three dilutions. “This increases the analytical error for the analysis up to 5–10%, which isn’t such a problem for products containing low amounts of cannabinoids, but if we are testing a concentrate that might be 70% THC, the potential range of 63–77% is huge.”
According to Lam and Eisenberg, the extreme focus on cost-savings reduces analytical validity in other ways, too. “Growers will provide us only a couple flowers for analysis because the material is expensive, but is that really representative of their entire batch? We know that flower potency can vary tremendously within the same plant depending on location, let alone between plants.”
In the end, you get what you pay for, and that means more variable results for the time being. But keep this in mind: People consume cannabis, so it is paramount that it be tested to ensure safety and label accuracy.
