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Setting a Standard: A Q&A With AOAC’s Cannabis Analytical Science Program

By Roxanne Newman

Published: Apr 07, 2020   
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In 2019 the Association of Official Analytical Collaboration (AOAC) created its cannabis analytical science program (CASP) for the primary goals of developing standards, official methods of analysis, training programs, and proficiency testing programs for the rapidly expanding cannabis testing industry.

Of specific interest to CASP was the development of a standard to analyze cannabinoids in hemp to support the increasing confusion surrounding the Farm Bill of 2018 and the US Domestic Hemp Production Program.

We caught up with Scott Coates, CASP program lead and senior director of the AOAC Research Institute, and Dr Holly Johnson, chief science officer of the American Herbal Products Association, ahead of their upcoming webinar with Analytical Cannabis to explore what CASP is and discuss its aims.

Roxanne Newman (RN): Can you give me a brief overview of CASP and what its primary goals are?

Scott Coates (SC): We recognised a couple of years ago that we were working with cannabis methods and were doing maybe one or two methods per year. We recognised that this is an important analytical area and decided that we needed to make more of an effort. So, we developed what we called CASP to speed up the process of delivering methods and standards. Also, this year we’re expanding to training and education and proficiency testing. So, in a nutshell, what we are doing with CASP is pulling all of the different programmes we have at AOAC together with a focus on cannabis.

RN: Other than supporting efforts around the Farm Bill, what are the other key areas of standard development CASP is engaged with in the cannabis industry right now?

SC: So, we're also looking at pesticides and other chemical contaminants in cannabis and cannabis products. And we also have a third working group looking at pathogens in cannabis and cannabis products. The first project was to create a standard and look for methods for aspergillus in cannabis. Aspergillus is tested in many state laboratories. The second standard and method will be for salmonella. And our third is for shiga toxin-producing E. coli. So, pretty broad effort across the analytical spectrum beyond just cannabinoids in hemp.

Holly Johnson (HJ): Yeah, we certainly are addressing the needs of hemp farmers and the hemp industry in the wake of the 2018 Farm Bill. But, just to mention again, AOAC is an international organisation and it's thought as authoritative for standard testing methods here in the US, but methods are used internationally as well. So, yes, we've been addressing the needs of the American hemp industry, but even before that AOAC had been focused on cannabis. But nothing is close to what CASP is doing now in terms of going in depth with each and every pathogen and taking a full approach to pesticides, etc. I think more than just the United States, we're focused on the international needs of people as this plant cannabis kind of comes out of the closet.

RN: In regard to aspergillus and pathogens, do other industry methods, such as from the food industry, aid in cannabis method development?

SC: Yeah, and that's where we typically start from, if we look at what's been done in the food microbiology pathogen area then we apply that to cannabis. Cannabis has some special issues. And then in particular, when we do the standards and the methods, that means that we're looking at cannabis in particular, and we're looking to have the method validated using a cannabis matrix.

HJ: From my perspective, it’s the validation parameters. So again, there might be a method that works really well for, say carrots, or something of that nature. But we're not sure that would work for cannabis flowers because they're so different. So, this is very common among different types and different botanical materials in commerce. But again, we at AOAC are really well known for validation parameters, we want to see the data. If we can set out the parameters that we want those data to meet the performance requirements of each method, then we open the call for methods and we actually see somebody out there who took that method, that was perhaps known to be really great for carrots, and now has performed that on cannabis and proven through their statistical and validation package that it actually does work reliably with cannabis materials. That gives the confidence to the industry and the regulators to be able to adopt those methods for use in cannabis.

RN: How difficult is developing an OMA? Can you give an example of one of these special issues where a method has been adapted?

HJ: There's official methods of action that look at the cannabinoid content in cannabis flowers and they work really well. They're fully validated and are official methods of action. So, if I go and take this official method of action, and I'm in a state cannabis market, I can test the entire cannabinoid profile. But those methods that are already official and that are in use by the state cannabis markets, they do such a great job; they report THC and the other cannabinoids, but they report them on an as-is basis. These are common terms with analytical chemistry and how you would analyse botanical materials. You can either report on an as-is basis, knowing that there'll be some residual moisture and water content in that plant material when you weigh it. Or you report on a dry weight basis or a dried basis, which is also very typical in analytical chemistry methods usually used for materials that are botanical materials that are known to be hygroscopic. So, if they sit on the bench for a little bit longer, they might absorb more water and cause the material to weigh more when you put it on the balance, which isn't really equivalent to a weight.

When you look at the emerging hemp industry here in the United States, the language in the December 2018 statute is on a dry weight basis. So what that indicates is that we needed a method that would go a step farther than the current official methods of action, and that would be able to incorporate a reporting on a dry weight basis, which is a fairly simple procedure, as you know if you're an analytical chemist. But we really needed this to be codified into the official method of action for the stakeholders, and really for the regulators as well. The USDA [the United States of Department of Agriculture] who's overseeing hemp in the United States, at least at the cultivation level, they want labs and farmers to be doing it the same way. Why is this so crucial? Because in the hemp markets, if there are differences between point 2 percent THC and 1.2 percent THC, that comes down to an illegal and a huge economic implication for the marketplace. So again, this is where analytical chemistry goes big time, this is real and this particular analysis and determination of THC on a dry weight basis in hemp materials has massive economic implications. It basically says, ‘is this material hemp and can it enter the legal marketplace?’ Or, must it be destroyed?’

That's why this determination is so critical. There needed to be these additional steps as per the Agricultural Marketing Service at the USDA as per their interim final rule and the statutory language put out in 2018 by Congress, they both require this on a dry weight basis reporting.

RN: What defines cannabis versus hemp from state to state and are organisations like CASP able to help dispel some of the confusion by providing standard methods that work for everyone?

HJ: Hemp is essentially defined as cannabis plants that cannot contain more than 0.3 percent total THC on a dry weight basis. That's a federal definition. Anything that's not hemp is considered other cannabis, you know, high THC cannabis and that's defined federally and that's federal law. There certainly are a patchwork of different regulations and different types of testing requirements from state to state in the cannabis market. But, as far as defining it, hemp is like one little slice of that big cannabis pie and it's fully right now defined on a federal level in the United States by THC content. That's the only parameter this one chemical analyte that makes it hemp and again, that's what makes this particular determination I talked about moments ago so critical.

RN: Are there any areas of expertise that you're really hoping to bolster within the CASP group?

SC: With the working groups that create standards and the extra panels that reduce the method, we do a gap analysis to see that we have deputies that we need to do that work. And occasionally we find that we do need some additional expertise and an example would be we're now working on mycotoxins in cannabis and as mycotoxins are between chemical contaminants and microbiology we have bolstered the group that's working on that chemical contaminants and added some microbiologists, and added some folks from the mycotoxin community to help put together that standard method performance requirements. Generally, we take a look at what the subject is and if we feel like we need some additional expertise, we'll go out and recruit tech parties. Also, as part of our development of training and education, we do have some training courses now that are cannabis focused and those training courses address what the actual standards are that we've come up with, and also, more importantly, how to demonstrate that a candidate method meets those requirements.

RN: What do you think are the most significant issues for cannabis testing right now?

HJ: Variability among labs in results is the biggest issue faced by the cannabis testing industry. Repeatability within a lab and then reproducibility among labs, those precision parameters are just what I see as really the most critical thing we need, we need the same material to, to push back the same result, or at least very close to the same result among labs, whether they be in different cities, states, etc. This also might not only be an adoption of standard testing methods, but it's again, the way that the industry evolved. There were no standard testing methods at the beginning, so every lab has made their own way about it and I think there's just been a slowness to adopt national testing standards. And it may not be just the adoption of those methods, it may also be the other things that CASP is trying to provide for the community in terms of full training, etc.

SC: Training and education for the analysts that aren't familiar with doing actually analytical methods and training on just basic analytical science. And then the other two things would be, drafted preference materials, so that laboratories can start checking their results against what they're supposed to be getting and proficiency testing, where you send one sample out to a number of laboratories and they report back what they get and demonstrate that they're getting correct results. All of those things CASP are working on. As I mentioned, we were rolling out training and education this summer and next month, we're getting ready to organise proficiency testing programme to identify how we can advance proficiency testing in this community. This is all geared to quality measurements, which is, I think at this point, maybe not so familiar with the tools of quality assurance and quality testing.

Scott Coates and Dr Holly Johnson will be presenting Update on Standards and Methods for Cannabis & Hemp Analysis on April 21. Click here to register your free place.

Roxanne Newman

Team Lead, Conference Production

Roxanne joined Analytical Cannabis in 2019 as conference producer, where she helps to organize our webinars, online symposia, and physical events in Europe and the US. She graduated from Anglia Ruskin University in 2019 with a 1st class Bachelor's in Biomedical Science and was also awarded the Undergraduate Prize for Physiology from the Physiological Society, London. During her studies, Roxanne also received a prestigious summer research studentship to investigate the effect of natural products on the gut epithelial.


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