By Kelsey Cagle, Frank L. Dorman, Jessica Westland No Comments
Sample preparation is an essential part of method development and is critical to successful analytical determinations. With cannabis and cannabis products, the analyst is faced with a very challenging matrix and targets that may range from trace level through percent level thus placing considerable demands on the sample preparation techniques.1 The optimal sample preparation, or “extraction”, method for potency analysis of cannabis flower was determined using a methanol extraction coupled with filtration using regenerated cellulose filters.
In the United States (US), Canada, and other countries where medicinal and/or adult recreational cannabis has been legalized, regulatory entities require a panel of chemical tests to ensure quality and safety of the products prior to retail sales2. Cannabis testing can be divided into two different categories: Quality and Safety. Quality testing, which includes potency analysis (also known as cannabinoid testing or cannabinoid content), is performed to analyze the product in accordance with the producer/grower expectations and government regulations. Safety testing is conducted under regulatory guidelines to ensure that consumers are not exposed to toxicants such as pesticides, mycotoxins, heavy metals, residual solvents and microbial contaminates.
Potency testing evaluates the total amount of cannabinoid content, specifically focusing on tetrahydrocannabinol (THC) and cannabidiol (CBD). In the US, the biggest push for accurate total THC is to differentiate between hemp (legally grown for industrial or medicinal use), which is defined as cannabis sativa with a THC limit ≤ 0.3 %, and cannabis (Cannabis spp.), which is any cannabis plant with THC measured above 0.3 %3. Potency testing is typically performed by liquid chromatography (LC) with UV detection to determine the quantity of major cannabinoids.
In addition to reporting THC and CBD, their respective precursors are also important for reporting total potency. Tetrahydrocannabinolic acid (THCA) is the inactive precursor to THC while cannabidiolic acid (CBDA) is the precursor to CBD.4,5
Methods and Materials
Sample Preparation
All samples were homogenized using an immersion blender with a dry material grinder. The nominal sample amounts were 200 mg of flower, 500 mg of edibles, and 250 mg of candy samples.
Potency Extraction Method (1)
Twenty milliliters (mL) of methanol (MeOH) was added to each sample. The samples were mechanically shaken for 10 minutes and centrifuged for 5 minutes.
Potency Extraction Method (2)
Ten mL of water was added to each sample. The samples were mechanically shaken for 10 minutes. 20 mL of acetonitrile (ACN) was then added to each sample and vortexed. An EN QuEChERS extraction salt packet was added to the sample. The samples were placed on a mechanical shaker for 2 minutes and then centrifuged for 5 minutes.
Each extract was split and evaluated with two filtration/cleanup steps: (1) a regenerated cellulose (RC) syringe filter (Agilent Technologies, 4 mm, 0.45 µm); (2) a PFTE syringe filter (Agilent Technologies, 4 mm, 0.45 µm). The final filtered extracts were injected into the ultra-performance liquid chromatograph coupled with a photodiode array detector (UPLC-PDA) for analysis.
Figure 1: Calibration curve for THC potency
Calibration
Standards were obtained for the following cannabinoids at a concentration of 1 mg/mL: cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabidiol (CBD), cannabigerol (CBG), cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), cannabinol (CBN), tetrahydrocannabinol (9-THC), cannabichromene (CBC), tetrahydrocannabinol acid (THCA). Equal volumes of each standard were mixed with MeOH to make a standard stock solution of 10 ug/mL. Serial dilutions were made from the stock to make concentrations of 5, 1, and 0.5 ug/mL for the calibration curve (Figure 1).
Instrumental Method
All instrument parameters were followed from Agilent Application Note 5991-9285EN.8 A UPLC with a PDA (Waters Corp, Milford, MA) detector was employed for potency analysis. An InfinityLab Poroshell 120 EC-C18, 3.0 x 50 mm, 2.7 um column (Agilent Technologies, Wilmington, DE) was utilized for compound separation. The organic mobile phase composition was 0.05 % (v/v) formic acid in HPLC grade MeOH and the aqueous mobile phase composition was 0.1 % (v/v) formic acid in HPLC grade water. The mobile phase gradient is shown in Table 1. The flow rate was 1 mL/min (9.5 minute total program), injection volume was 5 uL, and column temperature was 50 °C.
Table 1: LC mobile phase gradient for potency samples6
Discussion and Results
Table 2 summarizes the relative standard deviations (% RSD) were found for the THC calibrator (at 1 ug/mL) and one extract of a homogeneous sample (utilizing 7 replicates).
Table 2- %RSD values for the instrument response precision for THC in both the calibrations and the homogeneous extract.
The cannabinoid potency of various cannabis plant and cannabis product samples were determined for the various extraction techniques In the chromatograms THC was observed ~8.08 minutes and CBD was observed ~4.61 minutes (Figure 2).
Figure 2: Chromatogram of the 10ug/mL calibrator for potency/cannabinoid analysis
Total potency for THC & CBD were calculated for each sample using the equations below. Equation 1 was used because it accounts for the presence of THCA as well as the specific weight difference between THC and THCA (since THCA will eventually convert to THC, this needs to be accounted for in the calculations).
Table 3 shows the % THC and the total THC potency values calculated for the same flower samples that went through all four various potency sample preparation techniques as described earlier. Figure 3 also provides LC chromatograms for flower sample 03281913A-2 and edible sample 03281912-1.
Table 3-THC and Total THC potency values for the same cannabis flower sample processed through the combination of extractions and cleanups.Figure 3: Potency/Cannabinoid analysis chromatogram for flower sample 03281913A-2 (red trace) and edible sample 03281912-1 (green trace).
The results indicated that with the “Potency Extraction Method 2” (ACN/QuEChERS extraction) coupled with the RC filter provided a bias of 7.29 % greater for total THC % over the other extraction techniques. Since the other 3 techniques provided total THC values within 2% of each other, the total THC of the sample is more likely ~14%.
Since the sample dilution for the above data set reduced the CBD content, an undiluted sample was run and analyzed. This data is reported in Table 4.
Table 4- CBD and Total CBD potency values for the same cannabis flower sample processed through different sample preparation techniques.
The CBD results indicated that with the “Potency Extraction Method 1” (methanol extraction) coupled with RC filter, allowed for a greater CBD recovery. This may indicate the loss of CBD with an ACN/QuEChERS extraction.
With an average ~14% total THC and 0.06% total CBD for a homogenous cannabis flower sample, the optimal sample preparation extraction was determined to be a methanol extraction coupled with filtration using a regenerated cellulose filter. Since potency continues to remain at the forefront of cannabis regulatory testing it is important to utilize the right sample prep for your cannabis samples.
References
Wang M, Wang YH, Avula B, Radwan MM, Wanas AS, Mehmedic Z, et al. Quantitative Determination of Cannabinoids in Cannabis and Cannabis Products Using Ultra-High-Performance Supercritical Fluid Chromatography and Diode Array/Mass Spectrometric Detection. Journal of Forensic Sciences 2016;62(3):602-11.
Matthew Curtis, Eric Fausett, Wendi A. Hale, Ron Honnold, Jessica Westland, Peter J. Stone, Jeffery S. Hollis, Anthony Macherone. Cannabis Science and Technology, September/October 2019, Volume 2, Issue 5.
Sian Ferguson. https://www.healthline.com/health/hemp-vs-marijuana. August 27, 2020.
Taschwer M, Schmid MG. Determination of the relative percentage distribution of THCA and 9-THC in herbal cannabis seized in Austria- Impact of different storage temperatures on stability. Forensic Science International 2015; 254:167-71.
Storm C, Zumwalt M, Macherone A. Dedicated Cannabinoid Potency Testing Using the Agilent 1220 Infinity II LC System. Agilent Technologies, Inc. Application Note 5991-9285EN
This is the second piece in a two-part conversation with the founders of Veda Scientific, CEO Leo Welder and CSO Aldwin M. Anterola, PhD. To read part one, click here.
In part one, we chatted about their backgrounds, their approach to cannabis testing, their role in the greater industry and how they came into the cannabis industry.
In part two, we’re going down a few cannabis chemistry rabbit holes and realizing that what we don’t know is a lot more than what we do know. Join us as we delve into the world of volatile compounds, winemaking, the tastes and smells of cannabis, chicken adobo and much more.
Aaron: Alright so you mentioned the GCxGC/MS and your more advanced terpene analysis. How do you envision that instrument and that data helping your customers and/or the industry?
Leo: Some of the things that we envision will help is a better understanding of what compounds and what ratios will lead to desirable outcomes, things like better effects, aroma and flavor. By better understanding these things it’ll help the industry create better products.
I have a personal connection to this. My wife has some insomnia and she’s always had to take various forms of OTC pharmaceuticals to help with sleep. She tried using a 1:1 vape pen and it was a miracle worker for her for several months. The local dispensary had a sale on it, and she bought some extra. Unfortunately, even though she used it the same way as before, she got very serious anxiety, which obviously didn’t help her sleep. Every time she used the vapes from this same batch, she felt the same extreme anxiety. Sadly, she now had a lot of this product that she couldn’t use because it kept her awake rather than helping her sleep, so she went back to trying other OTC solutions. That’s a problem for both consumers and the industry at large. If people find something that works and provides a desired effect, they need to be able to rely on that consistency every time they purchase the product, leading to similar outcomes and not exaggerating the problem. That’s why I think consistency is so important. We’re taking two steps forward and one back when we have inconsistent products. How do we really grow and expand the availability of cannabis if we lose trust from our consumer base? What a lab can do and what we can do is provide data to cultivators and manufacturers to create that consistency and ultimately allow the market to expand into other demographics that are currently wary and less tolerant of that variance.
Vials of cannabis samples being prepped for collaborative research with the CESC
On a similar note, we have been having a lot of discussions with the CESC [Clinical Endocannabinoid System Consortium] down in San Diego. They are an advanced cannabis research group that we have been working with for over a year. We’ve started looking at the idea of varietals. To be more specific, because I’m not a wine connoisseur, varietals are the pinot noirs, the cabernets and sauvignon blancs of the industry. In the cannabis industry, consumers have indica and sativa, though we still argue over what that concept really means, if anything. But for the sake of argument, let’s say we have this dichotomy to use as a foundational decision tool for consumers- call it the red and white wine of the cannabis industry. How inaccessible would wine be if we just had red or white? Imagine if you went to a dinner party, really liked the wine you were drinking, and the host could only tell you that it was a red wine. You can’t go to a wine store and expect to find something similar to that wine if the only information you have is “red.” At a minimum, you need a category. So that’s what varietals are, the categories. The data that we can produce could help people in the industry who identify and establish the varietals based on their expertise as connoisseurs and product experts to find what those differences are chemically. Similarly, we’re also looking at appellation designations in California. So, we want to help provide tools for farmers to identify unique characteristics in their flower that would give them ability to claim and prove appellation designation.
Aldwin: The GCxGC/MS allows us to find more things besides the typical terpene profile with 20 or 40 terpenes. It allows us to go beyond those terpenes. The issue sometimes is that with a typical one-dimensional GC method, sure you could probably separate and find more terpenes, but the one dimension is not enough to separate everything that coelutes. And it’s not just terpenes. Some terpenes coelute with one another and that’s why people can see this inconsistency. Especially if you use a detector like an FID, we can see the compound limonene on the chromatogram, but there’s another terpene in there that is unknown that coelutes with limonene. So, this instrument is helping us get past the coeluting issue and solve it so that we know what peaks represent what terpenes.
The other bonus with our GCxGC/MS is that the coeluting compounds that were masked behind other terpenes are now revealed. There is a second dimension in the chromatogram where we can now detect some compounds in cannabis that would be hiding behind these large peaks if it were just a one-dimensional GC. Besides terpenes, we’ve found esters, alkanes, fatty acids, ketones, alcohols and aldehydes, as well as thiols. The terpenes are so plentiful in cannabis that these other compounds present at lower levels cannot be seen with just one-dimensional GC. There are just so many compounds in cannabis that the ones in small amounts are often masked. My analogy to highlight the importance of these minor compounds is like a dish; I am from the Philippines and I like chicken adobo. My father does it differently from my mom and someone else will do it differently in a different region. The base of the sauce is vinegar and soy sauce, but some people will do it differently and maybe add some bay leaf, garlic, pepper, or a touch of another spice. It’s still chicken adobo, but it tastes differently. Just like in cannabis, where yes, you have the same amount of THC in two different plants, but it’s still giving you a different experience. Some people say it’s because of terpenes, which is true in a lot of cases, but there are a lot of other volatile compounds that would explain better why certain dishes taste different.
2-D chromatogram showing four peaks separated by the GCxGC. With a traditional 1-D chromatogram, these peaks would coelute and not separate.
Leo: There’s been some recent developments too here that show it’s very significant. It’s like the difference between bland and spicy. And it could be the thiol. We identified a thiol in cannabis at the same time as other scientists reported an article that just came out on this subject.
Aldwin: Thiols are sulfur containing compounds that produce very powerful odors, giving cannabis the skunky smell. Skunks also produce thiols. It is very potent; you only need a little bit. It turns out that yes, that paper described thiols and we also saw them in our GCxGC/MS. These are the kinds of things that the GCxGC can show you. Those very tiny amounts of compounds that can have a very powerful impact. That’s one that we know for sure is important because it’s not just us that’s finding out that GCxGC can detect this.
Not everything is about THC or the high amount of the compounds in the flower. This paper and our concurrent findings indicated that the skunkier smelling strains contained very small amounts of thiols and you can recognize their presence quite readily. It’s not a terpene, but it’s producing a distinct flavor and a powerful smell.
Aaron: Okay, so why is this useful? Why is it so important?
Leo: I would say two things in particular that we know of that are issues currently, both related to scents. We mentioned this earlier. We do know that farmers with breeding programs are trying to target particularly popular or attractive scent profiles, whether it be a gas or fruity aroma. Right now, when they get the flower tested and review the terpene profile, it isn’t enough information to help them identify what makes them chemically distinct. We hear time and again that farmers will say their terpene profile is not helpful in identifying specific scents and characteristics. They are looking for a fingerprint. They want to be able to identify a group of plants that have a similar smell and they want a fingerprint of that plant to test for. Otherwise, you have to sniff every plant and smell the ones that are most characteristic of what they’re targeting. For larger operations, walking through and smelling thousands of plants isn’t feasible.
Once we can identify that fingerprint, and we know which compounds in which ratios are creating the targeted aroma, we can run tests to help them find the best plants for breeding purposes. It’s about reproducibility and scalability.
Another value is helping people who are trying to categorize oils and strains into particular odor categories, similar to the varietals concept we’ve been talking about. Currently, we know that when manufacturers send multiple samples of oils with the same or similar scent to be tested, the results are coming back with significantly different terpene profiles. There is not enough data for them to chemically categorize products. It’s not that their categories are wrong, it’s just that the data is not available to help them find those boundaries.
Those are two issues that we know from conversations with customers that this particular piece of equipment can address.
Aldwin: Let’s start from what we find, meaning if you are using the GCxGC/MS, we are finding more terpenes that nobody else would be looking at. We have data that shows, for example, that certain standards are accounting for 60% or so of total terpene content. So a large percent is accounted for, but there is still quite a bit missing. For some strains there are terpenes that are not in common reference standards. Being able to know that and identify the reason why we have different terpenes in here unaccounted for is big. There are other things there beyond the standard terpenes.
Dr. Anterola working with the GCxGC/MS
What excites me sometimes is that I see some terpenes that are known to have some properties, either medical or antibacterial, etc. If you find that terpene looking beyond the list, you’ll find terpenes that are found in things like hardwood or perfumes, things that we don’t necessarily associate with the common cannabis terpenes. If you’re just looking for the limited number of terpenes, you are missing some things that you might discover or some things that might help explain results.
Leo: It’s also absolutely necessary for the medical side of things. Because of the federal limitations, cannabis hasn’t been researched nearly enough. We’re missing a lot of data on all of the active compounds in cannabis. We are finally starting to move into an era where that will soon be addressed. In order for certain medical studies to be successful, we need to have data showing what compounds are in what plants.
Drs. John Abrams and Jean Talleyrand of the CESC launched the Dosing Project in 2016. They have been studying the impact of cannabis flower for indications such as pain mitigation and sleep improvement, and now more recently mood, and appetite modulation. They categorize the THC & CBD content as well as flower aroma into 3 cannabinoid and 3 odor profiles. They are able to acquire quite a bit of data about how odor correlates with the outcomes. Because they were initially limited in terms of underlying natural product content data, they contacted us when they found out we acquired this equipment in 2020, and have stated that they are certain the data we will now be producing will take their research to the next level of understanding.
Aldwin: For quality control you are looking at specific things that would reflect properties in cannabis. There should be a 1:1 correspondence between properties observed and what we are measuring. The current assumption is that the terpenes we are looking at will tell us everything about how people would like it, with regards to flavor and smell preference. But we know for a fact that the limited terpenes most labs are measuring do not encapsulate everything. So, it is important for QC purposes to know for this particular strain or product, which everyone liked, what is it in there that makes everybody like it? If you just look at the typical terpene profile, you’ll find something close, but not exact. The GCxGC/MS shows us that maybe there’s something else that gives it a preferred property or a particular smell that we can explain and track. In one batch of flower, the consumer experiences it a certain way, and for another batch people experience it another way. We’d like to be able to understand what those differences are batch to batch so we can replicate the experience and figure out what’s in it that people like. That’s what I mean by consistency and quality control; the more you can measure, the more you can see.
Aldwin: Speaking to authenticity as well, in a breeding example, some growers will have this strain that they grew, or at least this is what they claim it to be, but what are the components that make those strains unique? The more analytes you can detect, the more you can authenticate the plant. Is this really OG Kush? Is this the same OG Kush that I’ve had before? Using the GCxGC/MS and comparing analytes, we can find authenticity in strains by finding all of the metabolites and analytes and comparing two strains. Of course, there is also adulteration- Some people will claim they have one strain that smells like blueberries, but we find a compound in it that comes from outside of cannabis, such as added terpenes. Proving that your cannabis is actually pure cannabis or proving that something has added terpenes is possible because we can see things in there that don’t come from cannabis. The GCxGC/MS can be used as a tool for proving authenticity or proving adulteration as well. If you want to trademark a particular strain, we can help with claiming intellectual property. For example, if you want to trademark, register or patent a new product, it will be good to have more data. More data allows for better description of your product and the ability to prove that it is yours.
Leo: One thing that I think is a very interesting use case is proving the appellations. It is our understanding that California rolled out a procedure for growers to claim an appellation, but with strict rules around it. Within those rules, they need to prove uniqueness of growing products in specific regions. The GCxGC/MS can help in proving uniqueness by growing two different strains in two different regions, mapping out the differences and seeing what makes a region’s cannabis unique. It’s valuable for growers in California, Oregon, Colorado to be able to prove how unique their products are. To prove the differences between cannabis grown in Northern California versus plants grown along the Central Coast. And of course, for people across the world to be able to really tell a story and prove what makes their cannabis different and special. To be able to authenticate and understand, we need to have more comprehensive data about properties in those strains. It could be terpenes, it could be esters or thiols. That’s what we’re excited about.
Aaron: From your perspective, what are some of the biggest challenges and opportunities ahead for the cannabis industry?
Aldwin: Getting ready for federal legalization is both a challenge and opportunity. A challenge because when it is federally legal, there will be more regulations and more regulators. It is also a challenge because there will be more businesses, more competition, that might get into the industry. It is opening up to other players, much bigger players. Big tobacco, mega labs and massive diagnostic testing companies might participate, which will be a challenge for us.
But it’s also an opportunity for us to serve more customers, to be more established at the federal level, to move to interstate commerce. The opportunity is to be ready here and now while other people are not here yet.
Another challenge and opportunity is education. Educating consumers and non-consumers. We have to realize and accept that cannabis is not for everybody, but everyone is a stakeholder, because they are our neighbors, parents or part of the medical establishment. It would be a disservice not to educate the non-consumers.
The medical establishment, they don’t have to be consumers but they need to know about cannabis. They don’t know as much as they should about cannabis and they need to know more, like how it could affect their patients for better or for worse, so they know how to help their patients better. There could be drug interactions that could affect the potency of other drugs. They need to know these things. Educating them about cannabis is a challenge. It’s also an opportunity for us to now come in and say that cannabis is here to stay and be consumed by more and more people, so we better know how to deal with it from a medical perspective.“This bucking bronco of a growth style will throw a lot of people off. We need to figure out what we can grab on to and ride out these waves.”
Law enforcement needs to be educated too. What THC level in the blood indicates impairment? It is still a challenge because we’re not there yet, we don’t have that answer quite yet. And it’s an opportunity to help educate and to find more answers for these stakeholders, so we can have regulations that make sense.
Leo: To Aldwin’s point, the biggest opportunity comes along with federal legalization as well as expanding the customer base beyond the traditional market. Since adult use was legalized in CA, we haven’t yet seen the significant expansion of the consumer population. We’re primarily seeing a legal serving of the market that already existed before legalization.
The reality is cannabis can be used in different ways than what we think of. We know it has medical benefits and we know it is enjoyed recreationally by people looking for high THC content and the highest high. But there is also this middle ground, much like the difference between drinking moonshine and having a glass of wine at dinner. The wine at dinner industry is much bigger than the mason jar moonshine industry. That’s really where the opportunity is. What’s the appeal to the broader market? That will be a big challenge, but it’s inevitable. It comes from everything we’ve talked about today, consistency in products, educating people about cannabis, normalizing it to a certain degree, varietals and appellations.
As an entrepreneur, I’m looking at this from a business perspective. Everyone talks about the hockey stick growth chart, but it is a very wavy hockey stick. I expect to see very significant growth in the industry for a while, but it will have a lot of peaks and valleys. It’ll essentially be whiplash. We are seeing this in California right now, with sky high prices in flower last year down to bottom of the barrel prices this year. We have to all figure out how to hang on. This bucking bronco of a growth style will throw a lot of people off. We need to figure out what we can grab on to and ride out these waves. The good ones will be fun and the bad ones will be painful and we know they are coming again and again and again. That’s the biggest challenge. People say ‘expect tomorrow to look a lot like today,’ but you really can’t expect tomorrow to look anything like today in the cannabis industry. Tomorrow will be totally different from today. We need to figure out, within all this chaos, what can we hang on to and keep riding the upward trajectory without getting thrown off the bronco.
Leo Welder, CEO of Veda Scientific, founded the business with Aldwin M. Anterola, PhD in July of 2019. A serial entrepreneur with experience in a variety of markets, he came to the industry with an intrigue for cannabis testing and analysis. After teaming up with Dr. Anterola, co-founder and chief science officer at Veda Scientific, they came together with the purpose of unlocking possibilities in cannabis. From the beginning, they set out with a heavy scientific interest in furthering the industry from a perspective of innovation and research.
Through discussing their clients’ needs and understanding their complex problems, the two realized they wanted to start a lab that goes well beyond the normal regulatory compliance testing. Innovation in cannabis looks like a lot of things: new formulations for infused products, better designs for vaping technology or new blends of genetics creating unique strains, to name a few. For the folks at Veda Scientific, innovation is about rigorous and concentrated research and development testing.
With the help of some very sophisticated analytical chemistry instruments, their team is working on better understanding how volatile compounds play a part in the chemometrics of cannabis. From varietals and appellations to skunky smells, their research in the chemistry of cannabis is astounding – and they’ve only begun to scratch the surface.
In this two-part series, we discuss their approach to cannabis testing, their role in the greater industry as a whole and we go down a few cannabis chemistry rabbit holes and find out that what we don’t know is a lot more than what we do know. In part one, we get into their backgrounds, how they came into the cannabis industry and how they are carving out their niche. Stay tuned for part two next week where we delve deep into the world of volatile compounds, winemaking, the tastes and smells of cannabis and chicken adobo.
Aaron G. Biros: Tell me about how you and your team came to launch Veda, how you entered the cannabis space and what Veda’s approach is to the role of testing labs in the broader cannabis industry.
Leo Welder, CEO of Veda Scientific
Leo Welder: I’m an entrepreneur. This is my third significant venture in the last fifteen years or so. So, I was intrigued by cannabis legalization broadly, because it is such a unique time in our history. I was always interested in participating in the industry in some way, but I didn’t see where would be a good fit for me. I used to meet monthly with a group of friends and fellow entrepreneurs for dinner and discussions and one member started working on the software side of the industry. He mentioned the testing element of cannabis in one of our meetings. I latched on to that and was intrigued by the concept of testing cannabis. I began to research it and found the role that testing plays in the cannabis industry is really significant. I found out that regulators rely pretty heavily on labs to make sure that products are safe, labels are accurate and that consumers have some protections. So, I thought that this is a space that I thought I could really find a calling in.
So, from that point I knew I needed to find a subject matter expert, because I am not one. I have business skills and experience in some technical fields but I am not a cannabis testing expert by any means. So, with that I started to look at a few different markets that I thought may have opportunity for a new lab, and I came across Aldwin’s business; he had a cannabis testing lab in Illinois at that time. I reached out to him, talked to him about my vision for the space and his thoughts and his vision and we really started to come together. From there, we researched various markets and ultimately chose to approach Santa Barbara County as our first foray together into the cannabis testing market.
Aldwin M. Anterola: As Leo mentioned, he was looking for a subject matter expert and I am very much interested in plant biochemistry. Which means I like to study how plants make these compounds that are very useful to us. For my PhD [in plant physiology], I was studying how cell cultures of loblolly pine produce lignin. Our lab was interested in how pine trees produce lignin, which is what makes up wood. Wood comes from phenolic compounds. You’ve probably heard of antioxidants and flavonoids – those are phenolic compounds. After my PhD, I wanted to do something different so I decided to work with terpenes.
I picked a very important terpene in our field, an anti-cancer compound called Taxol, produced from the bark of the yew tree. You have to cut trees to harvest it. We have ways of synthesizing it now. But at that time, we were trying to figure out how the tree produces that terpene. Of course, I’m interested in any compound that plants make. My interest in terpenes led me to cannabinoids which turn out to be terpenophenolics, thus combining the two interests in my professional field.
Aldwin M. Anterola, PhD, Co-Founder and Chief Science Officer at Veda Scientific,
So that’s the scientific and intellectual side of why I became interested in cannabis, but practically speaking I got into cannabis because of a consulting offer. A company was applying for a cultivation license, wanted to have a laboratory component of their business in their application, and hired me to write that part of their application. I was very familiar with HPLC, and had a GC/MS in the lab. I also have a background in microbiology and molecular biology so I can cover every test required at that time, and I knew I could research the other analytical techniques if necessary.
So, they did not get the license, but I figured I’d take what I wrote, once I received permission, and set up an independent laboratory together. But it’s hard to run a lab and be a professor at the same time. Also, the busines side of running a lab is something that I am not an expert in. Fortunately, Leo found me. Before that, I really got excited about this new industry. The concept of cannabis being now accessible to more people is so interesting to me because of how new everything is. I wanted to be involved in an industry like this and help in making it safe while satisfying my curiosity in this new field of research. As a scientist, those are the things that excite us: the things we didn’t have access to, we can now do. It opens up a whole new room that we want to unlock. It was my intellectual curiosity that really drove me. This opened up new research avenues for me as well as other ventures if you will. How can I be more involved? I thought to myself.
SIU boasts an impressive cannabis program, thanks largely to Dr. Anterola’s work there.
Back in 2014, I introduced cannabis research to our university [Southern Illinois University] and set up an industrial hemp program, which was DEA-licensed I gathered faculty that would be interested in studying hemp and cannabis and we now have a whole cannabis science center at the university. I teach a course in cannabis biology and because I also teach medical botany to undergraduate students, I was able to introduce [premed] students to the endocannabinoid system. Anyway, I can go on and on.
Outside of that I became involved with the AOAC and ASTM, and became a qualified assessor for ISO 17025:2017. I have been a member of the American Chemical Society since 2000 but there were no cannabis related activities there yet until relatively recently. But when they had the new cannabis chemistry subdivision, I am happy to participate in there as well . There are many avenues that I took to begin dabbling with cannabis, be it research, nonprofits, teaching, testing and more. Cannabis has basically infiltrated all areas of what I do as an academic.
Leo: I read his resume and I was like this is the guy! So back to your question, what’s Veda’s role as a testing lab in this space? What are we trying to build? We spent a lot of time trying to figure out what we wanted to be in this space. We came to understand that labs are not the tip of the spear for the market; that would be the growers, the retailers and the processors. We are a support, a service. We see ourselves as a humble, but competent guide. We provide the data for the tip of the spear, the people pushing the industry forward with support, data and the services to make sure they have the tools they need to build these great companies and great products with good cultivation practices and more, leading everyone to the next level of the cannabis industry. Our job is to support innovation, to provide quality compliance testing, to of course ensure safety, while also providing great R&D to these innovative companies.
Aldwin: I’d like to add a bit to that thought. Okay so that’s who we are, but what are we not? Because as Leo said I had a testing lab before we met [Advanced Herbal Analytics]. From there, I approach it as safety testing, making sure that before it gets to the end consumer, we are sort of like gate keepers keeping consumers safe. That’s one side to it, but we are not the people who are trying to make sure that none of the products get to the market. For some, that’s how we’re treated as.
People often look at testing labs like the police. We are not the people trying to limit products to market. Our approach is not to find faults. There is another way of being a testing lab that is less about finding faults in products and more about finding uniqueness. What makes your product different? With this new approach, we are much more focused on helping the best products make it to the shelves.
Aaron: Given that all state licensed labs have to provide the same tests as the other labs in that state, how does Veda differentiate itself?
Leo: Location was the first thing. We picked Santa Barbara County intentionally. We knew that some of the biggest operators, some of the most forward-thinking innovators were setting up shop here. Looking down the road, not just this year or next year but very long term, we wanted to start building a great, sustainable company. We wanted to build a brand that those kinds of companies would be receptive to. Building better and greater products. There’s one other lab in the county and that’s it. Whereas there are clusters of labs in other parts of the state. Part of the draw to Santa Barbara for us was that it is such a small, tight-knit community. We have worked very hard to build relationships in our community and to understand their challenges, helping them however we can.
Location and relationships. Getting to know the challenges that different size customers face, be it our greenhouse customers versus outdoor customers, or large-scale operations versus smaller manufacturing operations, the challenges are all different. Some people care about turnaround times, some more about R&D. If we understand our client’s problems, then we can provide better service. We see ourselves as problem solvers. We lean heavily on our technical team members like Aldwin, who not only have tremendous amounts of experience and education, but also great networks to utilize when a customer needs help, even when it falls outside of our local expertise.
The GCxGC/MS instrument, used for Veda’s advanced R&D testing
Last but certainly not least is the advanced R&D testing that we do. When we first started, we started talking to farmers and manufacturers trying to understand their challenges. What data were they not getting? How would a testing lab better serve them? So, we started investing strategically in certain instruments that would allow us to better serve them. We’ll get into this later as well, but we invested in a GCxGC/MS, which allows us to get more visibility into things beyond the typical panels, like more terpenes and other volatile compounds including thiols and esters. We did that because we knew there is value in that. The data our customers were getting prior just wasn’t enough to put together really great breeding programs or to manufacture really consistent products, you know, to move toward that next level of innovation in the industry.
Aldwin: Leo mentioned advanced R&D and it’s basically the same approach that I mentioned before. It’s not just telling you what you can and cannot do. It’s about asking them what do you want to do and what do you want from a lab? If we have a problem, let’s see if we can solve it. That’s how the GCxGC/MS came into play because we knew there was a need to test for many terpenes and other volatile compounds. The common complaint we received was why two terpene profiles differ so much from each other, even from the same genetics.
This is something that would actually give the customer, the cultivator or the manufacturer: data about their product that they can actually use. For consistency, for better marketing and other reasons. We are trying to help them answer the questions of ‘how can I make my product better?’
You know, for example, clients would tell us they want something that has a specific taste or smells a certain way. Nobody is telling them what makes the flavor or smell. There is a need there that we can fill. We are trying to provide data that they, the customers, need so that they can improve their breeding programs or their formulations. Data they can use, not just data they need in order to comply with regulations. They would ask us what we can do. We listen to our customers and we try and help as best we can. We don’t know every answer. We are discovering there is a lot more to terpenes than what you can find on a traditional one dimensional gas chromatogram. Some of the terpene data that our clients had previously is not really actionable data, which is where the GCxGC/MS is helping us.
In part two, we delve deep into the world of volatile compounds, winemaking, the tastes and smells of cannabis and chicken adobo. Click here to read part two.
Like any other natural product, the biomass of legal cannabis can be contaminated by several toxic agents such as heavy metals, organic solvents, microbes and pesticides, which significantly influence the safety of the end products.
Let’s just consider the toxicological effects. Since cannabis products are not only administered in edible forms but also smoked and inhaled, unlike most agricultural products, pesticide residue poses an unpredictable risk to consumers. One example is the potential role of myclobutanil in the vape crisis.
Unfortunately, federal and state laws are still conflicted on cannabis-related pesticides. Currently, only ten pesticide products have been registered specifically for hemp by the U.S. Environmental Protection Agency. So, the question arises what has to be done with all pf the high-value, but also contaminated cannabis, keeping in mind that during the extraction processes, not only the phytocannabinoids get concentrated but the pesticides as well, reaching concentrations up to tens or hundreds of parts per million!
Currently, there are three different sets of rules in place in the regulatory areas of Oregon, California and Canada. These regulations detail which pesticides need to be monitored and remediated if a certain limit for each is reached. Because the most extensive and strict regulations are found in Canada, RotaChrom used its regulations as reference in their case study.
Centrifugal Partition Chromatographic (CPC) system
To illustrate that reality sometimes goes beyond our imagination, we evaluated the testing results of a THC distillate sample of one of our clients. This sample contained 9 (!) pesticides, of which six levels exceeded the corresponding action limits. The most frightening, however, regarding this sample, is that it contained a huge amount of carbofuran, a category I substance. It is better not to think of the potential toxicological hazard of this material…
The CPC-based purification of CBD is a well-known and straightforward methodology. As the elution profile on the CPC chromatogram of a distillate shows, major and minor cannabinoids can be easily separated from CBD. At RotaChrom, this method has been implemented at industrial-scale in a cost effective and high throughput fashion. In any case, the question arises: where are the pesticides on this chromatogram? To answer this, we set ourselves the goal to fully characterize the pesticide removing capability of our methodologies.
Our results on this topic received an award at the prestigious PREP Conference in 2019. The ease of pesticides removal depends on the desired Compound of Interest.
Here is a quick recap on key functionalities of the partition chromatography.
Separation occurs between two immiscible liquid phases.
The stationary phase is immobilized inside the rotor by a strong centrifugal force.
The mobile phase containing the sample to be purified is fed under pressure into the rotor and pumped through the stationary phase in the form of tiny droplets (percolation).
The chromatographic column in CPC is the rotor: cells interconnected in a series of ducts attached to a large rotor
Simple mechanism: difference in partition
Let’s get into the chemistry a bit:
The partition coefficient is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium. This ratio is therefore a comparison of the solubilities of the solute in these two liquid phases.
The CPC chromatogram demonstrates the separation of Compounds of Interest based on their unique partition coefficients achieved through a centrifugal partition chromatography system.
CPC can be effectively used for pesticide removal. About 78% of the pesticides around CBD are very easy to remove, which you can see here:
In this illustration, pesticides are in ascending order of Kd from left to right. CBD, marked with blue, elutes in the middle of the chromatogram. The chart illustrates that most polar and most apolar pesticides were easily removed beside CBD. However, some compounds were in coelution with CBD (denoted as “problematic”), and some compounds showed irregular Kd-retention behavior (denoted as “outliers”).
If pesticides need to be removed as part of THC purification, then the pesticides that were problematic around CBD would be easier to remove and some of the easy ones would become problematic.
To simulate real-world production scenarios, an overloading study with CBD was performed, which you can see in the graph:
It is easy to see on the chromatogram that due to the increased concentration injected onto the rotor, the peak of CBD became fronting and the apparent retention shifted to the right. This means that pesticides with higher retention than CBD are more prone to coelution if extreme loading is applied.
To be able to eliminate problematic pesticides without changing the components of the solvent system, which is a typical industrial scenario, the so-called “sweet spot approach” was tested. The general rule of thumb for this approach is that the highest resolution of a given CPC system can be exploited if the Kd value of the target compounds fall in the range of 0.5-2.0. In our case, to get appropriate Kd values for problematic pesticides, the volume ratio of methanol and water was fine-tuned. Ascending mode was used instead of descending mode. For the polar subset of problematic pesticides, this simple modification resulted in an elution profile with significantly improved resolution, however, some coelution still remained.
In the case of apolar pesticides, the less polar solvent system with decreased water content in ascending mode provided satisfactory separation.
Moreover, if we focus on this subset in the three relevant regulatory areas, the outcome is even more favorable. For example, myclobutanil and bifenazate, dominant in all of the three regulatory regions, are fully removable in only one run of the CPC platform.
Based on these results, a generic strategy was created. The workflow starts with a reliable and precise pesticide contamination profile of the cannabis sample, then, if it does not appear to indicate problematic impurity, the material can be purified by the baseline method. However, if coeluting pesticides are present in the input sample, there are two options. First, adjusting the fraction collection of the critical pesticide can be eliminated, however the yield will be compromised in this case. Alternatively, by fine-tuning the solvent system, a second or even a third run of the CPC can solve the problem ultimately. Let me add here, that a third approach, i.e., switching to another solvent system to gain selectivity for problematic pesticides is also feasible in some cases.
In review, RotaChrom has conducted extensive research to analyze the list of pesticides according to the most stringent Canadian requirements. We have found that pesticides can be separated from CBD by utilizing our CPC platform. Most of these pesticides are relatively easy to remove, but RotaChrom has an efficient solution for the problematic pesticides. The methods used at RotaChrom can be easily extended to other input materials and target compounds (e.g., THC, CBG).
Remediation of delta-9 tetrahydrocannabinol (d9-THC) has become a hot button issue in the United States ever since the Drug Enforcement Agency (DEA) released their changes to the definitions of marijuana, marijuana extract, and tetrahydrocannabinols exempting extracts and tetrahydrocannabinols of a cannabis plant containing 0.3% or less d9-THC on a dry weight basis from the Controlled Substances Act. That is because, as a direct consequence, all extracts and tetrahydrocannabinols of a cannabis plant containing more than 0.3% d9-THC became explicitly under the purview of the DEA, including work-in-progress “hemp extracts” that because of the extraction process are above the 0.3% d9-THC limit immediately upon creation.
The legal ramifications of these changes to the definitions on the “hemp extracts” marketplace will not be addressed. Instead, this article focuses on the amount of d9-THC that is available in the plant material prior to extraction and tracks a “hemp extract” from the point it falls out of compliance to the point it becomes compliant again and stresses the importance of accurate track-n-trace protocols at the processing facility. The model developed to support this article was intended to be academic and was designed to follow the d9-THC portion of a “hemp extract” through the lifecycle of a typical CO2-based extract from initial extraction to THC remediation. A loss to the equipment of 2% was used for each step.
Initial Extraction
For this exercise, a common processing scenario of 1000 kg of plant material at 10% cannabidiol (CBD) and 0.3% d9-THC by weight was modeled. This amount, depending on scale of operations, can be a facility’s total capacity for the day or the capacity for a single run. 1000 kg of plant material at 0.3% d9-THC has 3 kg of d9-THC that could be extracted, purified, and diverted into the marketplace. CO2 has a nominal extraction efficiency of 95%, meaning some cannabinoids are left behind in the plant material. The same can be said about the recovery of the extract from the equipment. Traces of extract will remain in the equipment and this little bit of material, if unaccounted for, can potentially open an operator up to legal consequences. Data for the initial extraction is shown in Image 1.
Image 1: Summary Data Table for Typical CO2-based Extraction of Phytocannabinoids
As soon as the initial extract is produced it is out of compliance with the 0.3% d9-THC limit to be classified as a “hemp extract”, and of the 3 kg of d9-THC available, the extract contains approx. 2.8 kg, because some of the d9-THC remains in the plant material and some is lost to the equipment.
Dewaxing via Winterization and Solvent Removal
Dewaxing a typical CO2 extract via winterization is a common process step. For this exercise, a wax content of 30% by weight was used. A process efficiency of 98% was attributed to the wax removal process and it was assumed that 100% of the loss can be accounted for in the residue recovered from the equipment rather than in the removed waxes. Data for the winterization and solvent recovery are shown in Image 2 and 3.
Image 2: Summary Data Table for Typical Winterization of a CO2 ExtractImage 3: Summary Data Table for Solvent Removal from a CO2 Extract
Two things occur during winterization and solvent removal, non-target constituents are removed from the extract and there is compounded loss from multiple pieces of process equipment. These steps increase the concentration of the d9-THC portion of the extract and produce two streams of noncompliant waste.
Decarboxylation & Devolatilization
Most cannabinoids in the plant material are in their acid form. For this exercise, 90% of the cannabinoids were considered to be acid forms. Decarboxylation is known to produce a mass difference of 87.7%, i.e. the neutral forms are 12.3% lighter than the acid forms. Heat was modeled as the primary driver and a process efficiency of 95% was used for the conversion rate during decarboxylation. To simplify the model, the remaining 5% acidic cannabinoids are presumed destroyed rather than degraded into other compounds because the portion of the cannabinoids which get destroyed versus degrade into other compounds varies from process to process.
Devolatilization is the process of removing low-molecular weight constituents from an extract to stabilize it prior to distillation. Since the molecular constituents of cannabis resin extracts vary from variety to variety and process to process, the extracts were assumed to consist of 10% volatile compounds. The model combines the decarboxylation and devolatilization steps to account for complete decarboxylation of the available acidic cannabinoids and ignores their weight contribution to the volatiles collected during devolatilization. Destroyed cannabinoids result in an amount of loss that can only be accounted for through a complete mass balance analysis. Data for decarboxylation and devolatilization are shown in Image 4.
Image 4: Summary Data Table for Decarboxylation and Devolatilization of a CO2 Extract
As the extract moves along the process train, the d9-THC concentration continues to increase. Decarboxylation further complicates traceability because there is both a known mass difference associated with the process and an unknown mass difference that must be calculated and justified.
Distillation
A two-pass distillation was modeled. On each pass a portion of the extract was removed to increase the cannabinoid concentration in the recovered material. Average data for distilled “hemp extracts” was used to ensure the model did not over- or underestimate the concentration of the cannabinoids in the distillate. The variables used to meet these data constraints were derived experimentally to match the model to the scenario described and are not indicative of an actual distillation. Data for distillation is shown in Image 5.
Image 5: Summary Data Table for Distillation of a Decarboxylated and Devolatilized Extract
After distillation, the d9-THC concentration is shown to have increased by 874% from the original concentration in the plant material. Roughly 2.2 kg of the available 3 kg of d9-THC remains in the extract, but 0.8 kg of d9-THC has either ended up in a waste stream or walking out the door.
Chromatography – THC Remediation Step 1
Chromatography was modeled to remove the d9-THC from the extract. Because there are several systems with variable efficiency rates at being able to selectively isolate the d9-THC peak from the eluent stream, the model used a 5% cut-off on the front-end and tail-end of the peak, i.e. 5% of the material before the d9-THC peak and 5% of the material after the d9-THC peak is assumed to be collected along with the d9-THC. Data for chromatography is shown in Image 6.
Image 6: Summary Data Table for d9-THC Removal using Chromatography
After chromatography, a minimum of three products are produced, compliant “hemp extract”, d9-THC extract, and noncompliant residue remaining in the equipment. The d9-THC extract modeled contains 2.1 kg of the available 3 kg in the plant material, and is 35% d9-THC by weight, an increase of 1335% from the distillation step and 11664% from the plant material.
CBN Creation – THC Remediation Step 2
For this exercise, the d9-THC extract was converted into cannabinol (CBN) using heat rather than cyclized into d8-THC, but a similar model could be used to account for this scenario. The conversion rate of the cannabinoids into CBN through heat degradation alone is low. Therefore, the model assumes half of the available cannabinoids in the d9-THC extract are converted to CBN. The entirety of the remaining portion of the cannabinoids are assumed to convert to some form of degradant rather than a portion getting destroyed. Data for THC destruction is shown in Image 7.
Image 7: Summary Data Table for THC Destruction through Degradation into CBN
Only after the CBN cyclization step has completed does the product that was the d9-THC extract become compliant and classifiable as a “hemp extract.”
Image 8: Summary Data Table for Reconciliation of the d9-THC Portion of the Hemp Extract
Throughout the process, from initial extraction to the final d9-THC remediation step, loss occurs. Of the 3 kg of d9-THC available in the plant material only 2.1 kg was recovered and converted to CBN. 0.9 kg was either lost to the equipment, destroyed in the process, attributable to the mass difference associated with decarboxylation, or was never extracted from the plant material in the first place. All of these potential areas of product loss should be identified, and their diversion risk fully assessed. Not every waste stream poses a risk of diversion, but some do; having a plan in place to handle waste the DEA considers a controlled substance is essential. Without a track-n-trace program following the d9-THC and identifying the potential risk of diversion would be impossible. The point of this is not to instill fear, instead the intention is to shed light on a very real issue “hemp extract” producers and state regulators need to understand to protect themselves and their marketplace from the DEA.
Dr. Markus Roggen is a chemist, professor, cannabis researcher and founder & CEO of Complex Biotech Discovery Ventures (CBDV). Founder & CEO of Ascension Sciences (ASI), Tomas Skrinskas has been at the leading edge of transformative healthcare technologies, including computer assisted surgery, surgical robotics and genetic nanomedicines, for over 15 years.
Leading researchers from the cannabis industry – Dr. Markus Roggen (Complex Biotech Discovery Ventures) and Tomas Skrinskas (Ascension Sciences) – highlight the challenges facing the industry’s current compliance testing standards and the opportunities emerging from the latest developments in nanotechnology and advanced analytical testing. Here are the key insights from the discussion.
What are the current compliance testing requirements for cannabis products? Are they sufficient in ensuring safety and quality?
In the current landscape, Canada’s compliance testing requirements are clearly laid out in the form of guidance documents. Specifically, for pesticide testing, cannabinoid concentration content in products, heavy metals, etc. Compliance testing can be roughly divided into two categories: 1) establishing the concentrations of wanted compounds, and 2) ensuring that unwanted compounds do not exceed safety limits.
In the first category, cannabinoids and terpenes are quantified. Their presence or absence is not generally forbidden but must stay within limits. For example, for material to be classified as hemp, the THC concentration cannot exceed 0.3 %wt., or a serving of cannabis edible should contain below 5 mg of THC. The second category of compliance testing focuses on pesticides, mold and heavy metals. The regulators have provided a list of substances to test for and set limits on those.
Are those rules sufficient to ensure safety and quality? Safety can only be ensured if all dangerous compounds are known and tested for. Take for example Vitamin E acetate, the substance linked to lung damage in some THC vape consumers and the EVALI outbreak. Prior to the caseload in the Fall of 2019, there were no requirements to test for it. It’s not only additives that are of concern. THC distillates often show THC concentrations of 90% plus 5% other cannabinoids. What are the last 5% of this mixture? Currently, those substances have not been identified. Are they safe? There is no concrete way to determine that.
The aforementioned guidelines have the best intentions, but do not adequately address two key obstacles the industry is currently facing: 1) what happens in practice, and 2) what can easily be audited? Making sure people follow the requirements is the challenge, and it comes down to variability of the tests. Testing has to happen on the final form of the product as well as every “batch,” but there is little guidance on how that is defined. With so much growth happening in the industry, how are these records even tracked and scrutinized?
And finally, there’s the question of quality. How do you define quality? Before establishing quantifiable quality attributes, it can’t be tested.
If compliance testing is insufficient, then why aren’t more cannabis companies testing beyond Health Canada’s requirements?
Compliance testing has always been focused on the end product, THC and CBD levels, and consumer safety. As long as cannabis companies are testing to determine this, doing further testing means added costs to the producer. There is a rush to get cannabis products to the new market because many consumers are eager to buy adult use products such as extracts or edibles, and quality is not the biggest selling point at this very moment.
However, there are unrealized advantages to advanced analytical testing that go beyond Health Canada’s requirements and that offer greater benefits to cannabis producers and product developers. Producers often see testing as an added cost to their production that is forced upon them by the regulators and will only test once the product is near completion. For cannabinoid therapeutics and nutraceuticals, advanced analytical testing is critical for determining the chemical makeup and overall quality of the formulation. This is where contract researchers, such as Ascension Sciences, come in to offer tests for nanoparticle characterization, cannabinoid concentration, dissolution profiles and encapsulation efficiency.
A lack of budget and awareness have prevented cannabis companies from advanced analytical testing. However, testing that goes beyond lawful requirements is an opportunity to save money and resources in the long term. This is where companies, like Complex Biotech Discovery Ventures (CBDV), offer in-process testing that provides a deep characterization and analysis of cannabis samples during every stage of product development. If tests are conducted during production, inefficiencies in the process are revealed and mistakes are spotted early on. For example, testing the spent cannabis plant material after extraction can verify if the extraction actually went through to completion. In another case, testing vape oil before it goes into the vape cartridges and packaging allows producers to detect an unacceptable THC concentration before they incur additional production costs.
Which methods are the most successful for cannabis testing?
The most effective method is the one that best determines the specific data needed to meet the desired product goal. For example, NMR Spectroscopy is paramount in assessing the quality of a cannabis sample and identifying its precise chemical composition.
HPLC (liquid/gas chromatography) is the most precise method for quantifying THC, CBD and other known cannabinoids. However, if a cannabis extractor wants to quickly verify that their oil has fully decarboxylated, then an HPLC test will likely take too long and be too expensive. In this case, IR (Infrared Spectroscopy) offers a faster and more cost-effective means of obtaining the needed data. Therefore, it ultimately depends on the needs of the producer and how well the testing instruments are maintained and operated.
What’s next in analytical testing technology? What are you working on or excited about?
In terms of compliance, regulations to standardize the testing is the hot topic at the moment. For nanotechnology and nanoparticles, the big question now is what is known as the “matrix” of the sample. In other words, what are the cannabinoids, and what else is in the sample that’s changing your results? The R&D team at Ascension Sciences is in the process of developing a standardized method for this to combat the issues mentioned earlier in the interview.
The smoke analyzer in CBDV’s lab
Ascension Sciences is also excited about characterizing nanoparticles over time to determine how cannabinoids are released and how that data can be transferred or made equivalent to consumer experiences. For example, if a formulation with quicker release, faster onset and better bioavailability is found in the lab, product development would be more efficient and effective when compared to other, more anecdotal methods.
At CBDV, the team is working on in-process analytical tools, such as decarboxylation monitoring via IR Spectroscopy and NMR Spectroscopy. CBDV is also looking at quantifying cannabis product quality. The first project currently in motion is to identify and quantify cannabinoids, terpenes, and other compounds present when vaping or smoking a joint using a smoke analyzer.
A lack of budget and awareness have prevented cannabis companies from testing beyond what’s required by Health Canada. Compliance testing is designed to ensure safety, and for good reason, but it is currently insufficient at determining the quality, consistency and process improvements. As the above factors are necessary for the advancement of cannabis products, this is where further methods, such as advanced analytical testing, should be considered.
Back in August, Lake Superior State University (LSSU) announced the formation of a strategic partnership with Agilent Technologies to “facilitate education and research in cannabis chemistry and analysis.” The university formed the LSSU Cannabis Center of Excellence (CoE), which is sponsored by Agilent. The facility, powered by top-of-the-line Agilent instrumentation, is designed for research and education in cannabis science, according to a press release.
Chemistry student, Justin Blalock, calibrates an Agilent 1290 Ultra-High Pressure Liquid Chromatograph with a 6470 Tandem Mass Spectrometer in the new LSSU Cannabis Center of Excellence, Sponsored by Agilent.
The LSSU Cannabis CoE will help train undergraduate students in the field of cannabis science and analytical chemistry. “The focus of the new LSSU Cannabis CoE will be training undergraduate students as job-ready chemists, experienced in multi-million-dollar instrumentation and modern techniques,” reads the press release. “Students will be using Agilent’s preeminent scientific instruments in their coursework and in faculty-mentored undergraduate research.”
The facility has over $2 million dollars of Agilent instruments including their UHPLC-MS/MS, UHPLC-TOF, GC-MS/MS, LC-DAD, GC/MS, GC-FID/ECD, ICP-MS and MP-AES. Those instruments are housed in a 2600 square-foot facility in the Crawford Hall of Science. In February earlier this year, LSSU launched the very first program for undergraduate students focused completely on cannabis chemistry. With the new facility and all the technology that comes with it, they hope to develop a leading training center for chemists in the cannabis space.
Dr. Steve Johnson, Dean of the College of Science and the Environment at LSSU, says making this kind of instrumentation available to undergraduate studies is a game changer. “The LSSU Cannabis Center of Excellence, Sponsored by Agilent was created to provide a platform for our students to be at the forefront of the cannabis analytics industry,” says Dr. Johnson. “The instrumentation available is rarely paralleled at other undergraduate institutions. The focus of the cannabis program is to provide our graduates with the analytical skills necessary to move successfully into the cannabis industry.”
Storm Shriver is the Laboratory Director at Unitech Laboratories, a cannabis testing lab in Michigan, and sounds eager to work with students in the program. “I was very excited to learn about your degree offerings as there is a definite shortage of chemists who have experience with data analysis and operation of the analytical equipment required for the analysis of cannabis,” says Shriver. “I am running into this now as I begin hiring and scouting for qualified individuals. I am definitely interested in a summer internship program with my laboratory.”
LSSU hopes the new facility and program will help lead the way for more innovation in cannabis science and research. For more information, visit LSSU.edu.
Imagine this: you are taking medication for cancer pain. One day, it works perfectly. The next, you feel no relief. On some days, you need to take three doses just to get the same effect as one. Your doctor can’t be completely positive how much active ingredient each dose contains, so you decide for yourself how much medication to take.
Doesn’t seem safe, right? It is crucial that doctors know exactly what they are prescribing to their patients. They must know that their patients are receiving the exact same dose of medication in their prescription each time they take it, and that their medication contains only the intended ingredients.
consistency is key to creating products that are safe for consumers.In the cannabis industry, lack of certainty on these important factors is a major problem for drug manufacturers as they attempt to incorporate cannabidiol (CBD), a compound found in cannabis that has no psychoactive effects but many medical benefits, into pharmaceutical drugs.
When using these compounds as medications, purity is essential. Cannabis contains a wide variety of compounds. Delta-9 tetrahydrocannabinol (THC) is the most well-known compound and its main psychoactive one1. Safety regulations dictate that consumers know exactly what they are getting when they take a medication. For example, their CBD-based medications should not contain traces of THC.
The cannabis industry greatly needs a tool to ensure the consistent extraction and isolation of compounds. In 2017, the cannabis industry was worth nearly $10 billion, and it is expected to grow $57 billion more in the next decade2. As legalization of medical cannabis expands, interest in CBD pharmaceuticals is likely to grow.
If compounds such as CBD are going to be used in pharmaceutical drugs, consistency is key to creating products that are safe for consumers.
CBD’s Potential
CBD is a non-psychoactive compound that makes up 40 percent of cannabis extracts1. It is great for medical applications because it does not interfere with motor or psychological function. Researchers have found it particularly effective for managing cancer pain, spasticity in multiple sclerosis, and specific forms of epilepsy3.
Figure 1: The chemical structure of cannabidiol.
Other compounds derived from cannabis, such as cannabichromene (CBC) and cannabigerol (CBG), may also be beneficial compounds with medical applications. CBC is known to block pain and inflammation, and CBG is known for its use as a potential anti-cancer agent1.
Along with these compounds that provide medical benefits, there are psychoactive compounds that are used recreationally, such as THC.
“It will definitely be an advantage to have cannabis-based medications with clearly defined and constant contents of cannabinoids,” says Kirsten Müller-Vahl, a neurologist and psychiatrist at Hannover Medical School in Germany.
Creating a Standard Through Centrifugal Partition Chromatography
To obtain purified compounds from cannabis, researchers need to use technology that will extract the compounds from the plant.
Many manufacturers use some sort of chromatography technique to isolate compounds. Two popular methods are high performance liquid chromatography (HPLC) and flash chromatography. These methods have their places in the field, but they cannot be effectively and cost-efficiently scaled to isolate compounds. Instead, HPLC and flash chromatography may be better suited as analytical tools for studying the characteristics of the plant or extract. As cannabis has more than 400 chemical entities4, compound isolation is an important application.
This method is highly effective for achieving both high purity and recovery.Although molecules such as CBD can be synthesized in the lab, many companies would rather extract the compounds directly from the plant. Synthesized molecules do not result in a completely pure compound. The result, “is still a mixture of whatever cannabinoids are coming from a particular marijuana strain, which is highly variable,” says Brian Reid, chief scientific officer of ebbu, a company in Colorado that specializes in cannabis purification.
Currently, there is only one method available to researchers that completely allows them to isolate individual compounds: centrifugal partition chromatography (CPC).
The principle of CPC is similar to other liquid chromatography methods. It separates the chemical substances as the compounds in the mobile phase flow through and differentially interact with the stationary phase.
Where CPC and standard liquid chromatography differs is the nature of the stationary phase. In traditional chromatography methods, the stationary phase is made of silica or other solid particles, and the mobile phase is made of liquid. During CPC, the stationary phase is a liquid that is spun around or centrifuged to stay in place while the other liquid (mobile phase) moves through the disc. The two liquid phases, like oil and water, don’t mix. This method is highly effective for achieving both high purity and recovery. Chemists can isolate chemical components at 99 percent or higher purity with a 95 percent recovery rate5.
“CPC is ideal for ripping a single active ingredient out of a pretty complex mixture,” says Reid. “It’s the only chromatographic technique that does that well.”
The Need for Pure Compounds
High levels of purity and isolation are necessary for cannabis to be of true value in the pharmaceutical industry. Imagine relying on a medication to decrease your seizures, and it has a different effect every time. Sometimes there may be traces of psychoactive compounds. Sometimes there are too much or too little of the compound that halts your seizures. This is not a safe practice for consumers who rely on medications.“It’s hard to do studies on things you can’t control very well.”
Researchers working with cannabis desperately need a technology that can extract compounds with high purity rates. It is hard to run a study without knowing the precise amounts of compounds used. Reid uses a Gilson CPC 1000 system at ebbu for his cannabinoid research. With this technology, he can purify cannabinoids for his research and create reliable formulations. “Now that we have this methodology dialed in we can make various formulations —whether they’re water-soluble, sublingual, inhaled, you name it —with very precise ratios of cannabinoids and precise amounts of cannabinoids at the milligram level,” says Reid.
Kyle Geary, an internist at the University of Illinois at Chicago, is currently running a placebo-controlled trial of CBD capsules for Crohn’s disease. This consistent isolation is helpful for his research, as well. “Ideally, the perfect study would use something that is 100 percent CBD,” says Geary. “It’s hard to do studies on things you can’t control very well.”
The State of the Industry
While CBD is not considered a safe drug compound under federal law in the United States6, 17 states have recently passed laws that allow people to consume CBD for medical reasons7. Half of medicinal CBD users solely use the substance for treatment, a recent survey found8. As the industry quickly grows, it is crucial that consumer safety protocol keeps pace.
In June, the US Food and Drug Administration (FDA) approved the first drug that contains a purified drug substance from cannabis, Epidiolex9. Made from CBD, it is designed to treat Dravet Syndrome and Lennox-Gastaut syndrome, two rare forms of epilepsy. FDA Commissioner Scott Gottlieb said in the news release that although the FDA will work to support the development of high-quality cannabis-based products moving forward, “We are prepared to take action when we see the illegal marketing of CBD-containing products with serious, unproven medical claims. Marketing unapproved products, with uncertain dosages and formulations can keep patients from accessing appropriate, recognized therapies to treat serious and even fatal diseases.”
The industry should be prepared to implement protocols to ensure the quality of their CBD-based products. The FDA has issued warnings in recent years that some cannabinoid products it has tested do not contain the CBD levels their makers claim, and consumers should be wary of such products10. It’s hard to know when or if the FDA will begin regulating CBD-based pharmaceuticals. However, for pharma companies serious about their reputation, there is only one isolation method that creates reliable product quality: CPC.
National Institute on Drug Abuse. (2015, June 24). The Biology and Potential Therapeutic Effects of Cannabidiol. Retrieved from https://www.drugabuse.gov/about-nida/legislative-activities/testimony-to-congress/2016/biology-potential-therapeutic-effects-cannabidiol
Atakan, Z. (2012). Cannabis, a complex plant: Different compounds and different effects on individuals. Therapeutic Advances in Psychopharmacology,2(6), 241-254. doi:10.1177/2045125312457586
Gilson. (n.d.). Centrifugal Partition Chromatography (CPC) Systems. Retrieved from http://www.gilson.com/en/AI/Products/80.320#.WzVB2lMvyMI
Mead, A. (2017). The legal status of cannabis (marijuana) and cannabidiol (CBD) under US law. Epilepsy & Behavior, 70, 288-291.
ProCon.org. (2018, May 8). 17 States with Laws Specifically about Legal Cannabidiol (CBD) – Medical Marijuana – ProCon.org. Retrieved from https://medicalmarijuana.procon.org/view.resource.php?resourceID=006473
Borchardt, D. (2017, August 03). Survey: Nearly Half Of People Who Use Cannabidiol Products Stop Taking Traditional Medicines. Retrieved from https://www.forbes.com/sites/debraborchardt/2017/08/02/people-who-use-cannabis-cbd-products-stop-taking-traditional-medicines/#43889c942817
U.S. Food & Drug Administration. (2017). Public Health Focus – Warning Letters and Test Results for Cannabidiol-Related Products. Retrieved from https://www.fda.gov/newsevents/publichealthfocus/ucm484109.htm
Many physicians today treat their patients with cannabidiol (CBD, Figure 1), a cannabinoid found in cannabis. CBD is more efficacious over traditional medications, and unlike delta-9 tetrahydrocannbinol (THC), the main psychoactive compound in cannabis, CBD has no psychoactive effects. Researchers have found CBD to be an effective treatment for conditions such as cancer pain, spasticity in multiple sclerosis, and Dravet Syndrome, a form of epilepsy.
Figure 1. The structure of cannabidiol, one of 400 active compounds found in cannabis.
Most manufacturers use chromatography techniques such as high performance liquid chromatography (HPLC) or flash chromatography to isolate compounds from natural product extracts. While these methods are effective for other applications, they are not, however, ideal for CBD isolate production. Crude cannabis oil contains some 400 potentially active compounds and requires pre-treatment prior to traditional chromatography purification. Both HPLC and flash chromatography also require silica resin, an expensive consumable that must be replaced once it is contaminated due to irreversible absorption of compounds from the cannabis extract. All of these factors limit the production capacity for CBD manufacturers.
Additionally, these chromatography methods use large quantities of solvents to elute natural compounds, which negatively impacts the environment.
A Superior Chromatography Method
Centrifugal partition chromatography (CPC) is an alternative chromatography method that can help commercial CBD manufacturers produce greater quantities of pure CBD more quickly and cleanly, using fewer materials and generating less toxic waste. CPC is a highly scalable CBD production process that is environmentally and economically sustainable.
The mechanics of a CPC run are analogous to the mechanics of a standard elution using a traditional chromatography column. While HPLC, for instance, involves eluting cannabis oil through a resin-packed chromatography column, CPC instead elutes the oil through a series of cells embedded into a stack of rotating disks. These cells contain a liquid stationary phase composed of a commonly used fluid such as water, methanol, or heptane, which is held in place by a centrifugal force. A liquid mobile phase migrates from cell to cell as the stacked disks spin. Compounds with greater affinity to the mobile phase are not retained by the stationary phase and pass through the column faster, whereas compounds with a greater affinity to the stationary phase are retained and pass through the column slower, thereby distributing themselves in separate cells (Figure 2).
Figure 2. How CPC isolates compounds from complex, natural mixtures. As the column spins, the mobile phase (yellow) moves through each cell in series. The compounds in the mobile phase (A, B, and C) diffuse into the stationary phase (blue) at different rates according to their relative affinities for the two phases.
A chemist can choose a biphasic solvent system that will optimize the separation of a target compound such as CBD to extract relatively pure CBD from a cannabis extract in one step. In one small-scale study, researchers injected five grams of crude cannabis oil low in CBD content into a CPC system and obtained 205 milligrams of over 95% pure CBD in 10 minutes.
Using a liquid stationary phase instead of silica imbues CPC with several time and cost benefits. Because natural products such as raw cannabis extract adhere to silica, traditional chromatography columns must be replaced every few weeks. On the other hand, a chemist can simply rinse out the columns in CPC and reuse them. Also, unlike silica columns, liquid solvents such as heptane used in CPC methods can be distilled with a rotary evaporator and recycled, reducing costs.
Environmental Advantages of CPC
The solvents used in chromatography, such as methanol and acetonitrile, are toxic to both humans and the environment. Many environmentally-conscious companies have attempted to replace these toxic solvents with greener alternatives, but these may come with drawbacks. The standard, toxic solvents are so common because they are integral for optimizing purity. Replacing a solvent with an alternative could, therefore, diminish purity and yield. Consequently, a chemist may need to perform additional steps to achieve the same quality and quantity achievable with a toxic solvent. This produces more waste, offsetting the original intent of using the green solvent.
CPC uses the same solvents as traditional chromatography, but it uses them in smaller quantities. Furthermore, as previously mentioned, these solvents can be reused. Hence, the method is effective, more environmentally-friendly, andeconomically feasible.
CPC’s Value in CBD Production
As manufacturers seek to produce larger quantities of pure CBD to meet the demand of patients and physicians, they will need to integrate CPC into their purification workflows. Since CPC produces a relativelyduct on a larger scale, it is equipped to handle the high-volume needs of a large manufacturer. Additionally, because it extracts more CBD from a given volume of raw cannabis extract, and does not use costly silica or require multiple replacement columns, CPC also makes the process of industrial-scale CBD production economically sustainable. Since it also uses significantly less solvent than traditional chromatography, CPC makes it financially feasible to make the process of producing CBD more environmentally-friendly.
As the cannabis marketplace evolves, so does the technology. Cultivators are scaling up their production and commercial-scale operations are focusing more on quality. That greater attention to detail is leading growers, extractors and infused product manufacturers to use analytical chemistry as a quality control tool.
Previously, using analytical instrumentation, like mass spectrometry (MS) or gas chromatography (GC), required experience in the laboratory or with chromatography, a degree in chemistry or a deep understanding of analytical chemistry. This leaves the testing component to those that are competent enough and scientifically capable to use these complex instruments, like laboratory personnel, and that is still the case. As recent as less than two years ago, we began seeing instrument manufacturers making marketing claims that their instrument requires no experience in chromatography.
Instrument manufacturers are now competing in a new market: the instrument designed for quality assurance in the field. These instruments are more compact, lighter and easier to use than their counterparts in the lab. While they are no replacement for an accredited laboratory, manufacturers promise these instruments can give growers an accurate estimate for cannabinoid percentages. Let’s take a look at a few of these instruments designed and marketed for quality assurance in the field, specifically for cannabis producers.
Ellutia GC 200 Series
Shamanics, a cannabis extractor in Amsterdam, uses Ellutia’s 200 series for QA testing
Ellutia is an instrument manufacturer from the UK. They design and produce a range of gas chromatographs, GC accessories, software and consumables, most of which are designed for use in a laboratory. Andrew James, marketing director at Ellutia, says their instrument targeting this segment was originally designed for educational purposes. “The GC is compact in size and lightweight in stature with a full range of detectors,” says James. “This means not only is it portable and easy to access but also easy to use, which is why it was initially intended for the education market.”
Andrew James, marketing director at Ellutia
That original design for use in teaching, James says, is why cannabis producers might find it so user-friendly. “It offers equivalent performance to other GC’s meaning we can easily replace other GC’s performing the same analysis, but our customers can benefit from the lower space requirement, reduced energy bills, service costs and initial capital outlay,” says James. “This ensures the lowest possible cost of ownership, decreasing the cost per analysis and increasing profits on every sample analyzed.”
Shamanics, a cannabis oil extraction company based in Amsterdam, uses Ellutia’s 200 series for quality assurance in their products. According to Bart Roelfsema, co-founder of Shamanics, they have experienced a range of improvements in monitoring quality since they started using the 200 series. “It is very liberating to actually see what you are doing,” says Roelfsema. “If you are a grower, a manufacturer or a seller, it is always reassuring to see what you have and prove or improve on your quality.” Although testing isn’t commonplace in the Netherlands quite yet, the consumer demand is rising for tested products. “We also conduct terpene analysis and cannabinoid acid analysis,” says Roelfsema. “This is a very important aspect of the GC as now it is possible to methylate the sample and test for acids; and the 200 Series is very accurate, which is a huge benefit.” Roelfsema says being able to judge quality product and then relay that information to retail is helping them grow their business and stay ahead of the curve.
908 Devices G908 GC-HPMS
908 Devices, headquartered in Boston, is making a big splash in this new market with their modular G908 GC-HPMS. The company says they are “democratizing chemical analysis by way of mass spectrometry,” with their G908 device. That is a bold claim, but rather appropriate, given that MS used to be reserved strictly for the lab environment. According to Graham Shelver, Ph.D., commercial leader for Applied Markets at 908 Devices Inc., their company is making GC-HPMS readily available to users wanting to test cannabis products, who do not need to be trained analytical chemists.
The G908 device.
Shelver says they have made the hardware modular, letting the user service the device themselves. This, accompanied by simplified software, means you don’t need a Ph.D. to use it. “The “analyzer in a box” design philosophy behind the G908 GC-HPMS and the accompanying JetStream software has been to make using the entire system as straightforward as possible so that routine tasks such as mass axis calibration are reduced to simple single actions and sample injection to results reporting becomes a single button software operation,” says Shelver.
He also says while it is designed for use in the field, laboratories also use it to meet higher-than-usual demand. Both RM3 Labs in Colorado, and ProVerde in Massachusetts, use G908. “RM3’s main goal with the G908 is increased throughput and ProVerde has found it useful in adding an orthogonal and very rapid technique (GC-HPMS) to their suite of cannabis testing instruments,” says Shelver.
Orange Photonics LightLab Cannabis Analyzer
Orange Photonics’ LightLab Cannabis Analyzer
Dylan Wilks, a third generation spectroscopist, launched Orange Photonics with his team to produce analytical tools that are easy to use and can make data accessible where it has been historically absent, such as onsite testing within the cannabis space. According to Stephanie McArdle, president of Orange Photonics, the LightLab Cannabis Analyzer is based on the same principles as HPLC technology, combining liquid chromatography with spectroscopy. Unlike an HPLC however, LightLab is rugged, portable and they claim you do not need to be a chemist to use it.
“LightLab was developed to deliver accurate repeatable results for six primary cannabinoids, D9THC, THC-A, CBD, CBD-A, CBG-A and CBN,” says McArdle. “The sample prep is straightforward: Prepare a homogenous, representative sample, place a measured portion in the provided vial, introduce extraction solvent, input the sample into LightLab and eight minutes later you will have your potency information.” She says their goal is to ensure producers can get lab-grade results.
The hard plastic case is a unique feature of this instrument
McArdle also says the device is designed to test a wide range of samples, allowing growers, processors and infused product manufacturers to use it for quality assurance. “Extracts manufacturers use LightLab to limit loss- they accurately value trim purchases on the spot, they test throughout their extraction process including tests on spent material (raffinate) and of course the final product,” says McArdle. “Edibles manufacturers test the potency of their raw ingredients and check batch dosing. Cultivators use LightLab for strain selection, maturation monitoring, harvesting at peak and tinkering.”
Orange Photonics’ instrument also connects to devices via Wi-Fi and Bluetooth. McArdle says cannabis companies throughout the supply chain use it. “We aren’t trying to replace lab testing, but anyone making a cannabis product is shooting in the dark if they don’t have access to real time data about potency,” says McArdle.
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