Colton Myers

Analysis of pesticides in cannabis products

3 Oct 2019

In this video, Dr. Nathaly Reyes Garcés explains a simple workflow for the accurate analysis of pesticides in cannabis products via solvent extraction and GC analysis. Colton Myers discusses his work analyzing terpenes in cannabis through headspace analysis. Myers identifies the difficulties in getting the less volatile terpenes into the gas stage and how Restek is overcoming these challenges. Ashlee Gerardi outlines the focus for Restek and how its team can help with bespoke cannabis testing workflows and method development, in the face of ongoing changes within the industry, new regulations coming into place and state-to-state differences.

- [Nathaly] My name is Nathaly Reyes. I work at Restek as an LC application scientist. I'm currently working the cannabis market on the development of particles for analysis of pesticides in different matrices. Today we're going to be showing simple workflow for analysis of both Oregon and California, lists of pesticides in samples in different matrices.
Specifically we're going to be working with brownies. What we're doing is basically a solvent extraction using acetonitrile. And then we're doing a very simple cleanup using an SB cartridge. After that for GC analysis, we do an additional cleanup step using PSA and magnesium sulfate. And for LC analysis, we just simply do a division of the original extract, and that's it.
We're going to be showing a very simple workflow. It is important because it gives the customers a possibility of having clean extracts without spending lots of money and having the sample prepped on. And at the same time, it's going to warranty that the instrument run time is going to be good for longer time, and at the same time, the results are going to be accurate and unbiased.
- [Colton] My name is Colton Myers. I work at Restek Corporation in our applications department. And a lot of my primary focus is on GC cannabis testing. So, I'm working on analyzing terpenes in cannabis. Typically this is done through headspace analysis, but what we're finding is that it is difficult to get some of those less volatile terpenes into the gas phase, so to make this more reproducible, and to collect better data on these terpenes, we're looking at different alternatives.
Our focus right now has been on using a direct immersion solid-phase microextraction. With this technique, we're able to collect good results for the sesquiterpenes which are the less volatile terpenes. And we found that we can do this reproducibly, so that's where our primary focus has been. Different growers or people producing cannabis products will use this information to get a better understanding of the flavor profiles of their products.
And, this also starts to play into the entourage effect, which is the way cannabinoids and terpenes interact. - [Ashlee] For Restek, our main focus is on analytical testing for consumers looking to do pesticides, residual solvents, terpenes, mycotoxins, and potency.
And, this can be done for manufacturer, a cultivation facility and then, of course, your QA laboratory. And so we're really trying to promote high-throughput simplicity in our workflows, and just overall good laboratory practices in the science behind cannabis testing. The cannabis and hemp market at large is constantly changing. There's new regulations going into place, modifications being made, and in addition to that, we don't have any standardized methods or even any federal legalization yet, so each state kind of has their own protocols that you have to comply with.
And, so it makes a unique challenge for this industry working with customers that have multiples locations in each state. So, if you're based in Colorado and have a lab there, you might only be looking at 13 pesticides. But, if you open up a facility in California, you've got to work on method development all over again, because now you're looking at 65 plus pesticides.