Any brewmaster from the more than 7,000 U.S. craft breweries will tell you one of two things: That their art is a science, or that their science is an art. The answer might depend upon the brewer’s individual approach, but a combination of experience, process, precise measurement and intuition is exactly what’s required to create great beer. In a very similar way, the cannabis industry has its own version of the brewmaster: Extraction technicians.
A cannabis extraction technician deploys knowledge from multiple science disciplines to apply industrial solvents, heat and pressure to plant matter through a variety of methods with the aim to chemically extract pure compounds. Extraction techs use their passion for the cannabis and hemp plants, combined with chemistry, physics, phytobiology and chemical engineering to help create a result that’s not quite art, but not quite completely science. By manipulating plant materials, pressure, heat and other variables, the extraction technician crafts the building block for what will become an edible, tincture or extract.
Similarly, brewmasters use their knowledge of multiple science disciplines like chemistry and microbiology, as well as different brewing processes and a variety of ingredients to develop creative recipes that result in consistent, interesting beers. The brewmaster’s work is both science and art, as well. And they also manipulate plant materials, pressure, heat and other variables to achieve their desired results.
“I would certainly consider brewing to be an art and a science, but it takes a very disciplined approach to create consistent, yet ever evolving beers for today’s craft market,” says Marshall Ligare, PhD. Research Scientist at John I. Haas, a leading supplier of hops, hop products and brewing innovations. “We work to ensure brewers can create something different with every new beer, as well as something that helps create an experience as well as a feeling.”
In both brewing and extraction, the art comes in the subjective experience of the craftsman and his or her ability to curate the infinite possibilities inherent in each process. However, both are a science in their requirement of establishing production methodologies that guarantee a consistent, reliable product experience every time to win customer loyalty (and regulatory compliance). In the same way hops determine recipes for beer flavors, the cannabis plant determines extraction recipes, especially considering the role that terpenoids play in the quality, flavor and effects of the end product.
The development of new and appealing cannabis products is beginning to mimic the vast variety of craft beers now found all over the world. In the same way beer connoisseurs seek out the perfect stout, lager or IPA, discriminating cannabis consumers now search for that gem of a single-origin, specialty-strain vaporizer oil or irresistible dab extract.
“I see an exciting new day for quality-focused, craft extraction that tells a story, not only of where the cannabis plant might have been grown and how, but also the care that was taken in the processing of that strain into smokable or edible oil,” says John Lynch, Founder of TradeCraft. “Imagine the impact in the marketplace when product-makers figure out how to do seasonal one-offs where engaged connoisseurs are willing to pay a premium for the art behind limited releases.”
In either process, you’re essentially creating art with science. Each process works with different strains. Each is concerned with chemical and flavor profiles. Each has its own challenges. In both worlds, quality depends upon consistency. You’re creating art, but you need to replicate that art over and over – which can only occur with strict control of the process. Brewmasters seek control of things like yeast quantity and health, oxygen input, wort nutritional status and temperature, among other things. In their pursuit, extraction technicians seek to control temperature, pressure and flow rate–as well as all the ways these variables interact with each other. What enables this control in both efforts is the equipment used to achieve results.
“A modern brewhouse is very much like a scientific laboratory,” Ligare says. “Brewers treat their setup with the same care and attention a scientist gives to their lab equipment, and are equally concerned with precision, cleanliness and the purity of the result. With each new beer, they want to develop a process that can be controlled and replicated.”
The key to creating a precise process is to use instrument-grade machinery that performs to specifications – and allows you to repeat the process again and again. The value of using high-quality instrumentation to manage and monitor either the brewing or extraction process cannot be overstated. Although it seems counterintuitive, this is where the “craft” comes into play for both brewing and cannabis extraction. Precise instrumentation is what allows the brewer or extraction “artist” to manipulate and monitor the conditions required to meet recipe standards. Along with the quality of the ingredients (hops, cannabis, hemp, etc.), the quality of the equipment utilized to create the product is one critical element impacting the end result. “Imagine the impact in the marketplace when product-makers figure out how to do seasonal one-offs where engaged connoisseurs are willing to pay a premium for the art behind limited releases.”
In cannabis extraction, a second crucial decision is determining which solvent is the best solution for the recipe you’re using and the end result you’re hoping to achieve. This decision is a part of the “craft” of extraction, and determined according to a combination of criteria. There’s no question that each solvent has a business case it serves best, and there is ongoingdebate about which approach is best. But overwhelmingly, the solvent that best serves the most business needs is CO2 due to its inherent versatility and ability to have its density tuned to target specific compounds.
“Control is what makes or breaks any craft product,” says Karen Devereux, Vice President of Northeast Kingdom Hemp. “We’re based in Vermont and love how Vermont is known for its quality craft beer, cheese and maple syrup. We wanted to bring that craft approach to hemp extraction, and everyone knows that any craft endeavor is focused on the details and getting them right again and again. You can’t do that without controlling every aspect of the process.”
Greater control of the process can also open up worlds of discovery. The inherent “tunability” of CO₂ enables the extraction technician to target specific compounds, enhancing the potential for experimentation and even whimsy. This can lead to entirely new products much in the way a brewer can control his process to create new, interesting beers.
American portrait photographer Richard Avedon famously declared that art is “about control,” describing the artistic process as “the encounter between control and the uncontrollable.” The same can be said for beer making and cannabis extraction. The more precisely you can control variables, the more options you’ll have for yourself and your customers. The more choices you’ll have with regard to different recipes and products. And the more loyalty you’ll ultimately generate among fans of your products.
Carbon Dioxide (CO2) extraction is a processing technique whereby CO2 is pressurized under carefully controlled temperatures to enable extraction of terpenes, cannabinoids and other plant molecules.
Green Mill Supercritical is a Pittsburgh-based manufacturing and engineering company focused on cannabis and hemp extraction. The company offers a range of CO2 extraction equipment where users can tune and control their extraction methods.
We spoke with Wes Reynolds, CEO of Green Mill Supercritical. Wes recently joined Green Mill as CEO and investor in the company after a long career at the Coca-Cola Company in senior sales and general management roles.
Aaron Green: Wes, thank you for taking the time to chat today. How did you get involved in Green Mill?
Wes Reynolds: I came out of a 20-year career at Coca-Cola, where I lived and worked around the world. I was a sales and general management guy with Coke, and learned a lot about running businesses and how to drive growth. I left Coke in 2017. After that successful career I wanted to be in the cannabis space. I felt like cannabis was a growing space with a lot of opportunity and a lot of misperceptions out there, particularly around the foundations of what I would call the “evil reputation” of cannabis. I just found that abhorrent and wanted to be part of changing it.
So I ran the Florida operations for Surterra, which is now called Parallel, for a year out of Tampa, and we did a great job of growing that business in Florida. As the president of the Florida operation for Surterra, I saw everything seed-to-shelf for the industry. We had a 300,000-square-foot greenhouse in Central Florida, we had dispensaries, we had all the production, distribution and all the marketing. I was really able to learn the industry top to bottom.
When I left Surterra, I started looking at various investment opportunities and thinking about what I might want to do next. I came across Green Mill out of Pittsburgh, and was really impressed with the technology that they had put together. Having run a company where we used CO2 extraction, I had experiences with systems that didn’t work when they were supposed to or didn’t work the way they were promised, which led to lots of downtime, lots of frustration and lots of babysitting. I was impressed with Green Mill’s engineering approach and decided that I’d like to be involved with them. I originally considered just being an investor, but more and more conversations led to a greater understanding of some basic business administrative needs that they had as well. One thing led to another and I agreed to come on as the CEO, and I’m also an investor.
I’m excited about what we’re doing at Green Mill. I think that bar none, we make the best supercritical CO2 extraction equipment out there. We continue to innovate on that every day. We want to push CO2 beyond known limits, which is our stated goal as a company. We believe in CO2 and we’re living our goal in that we really are pushing it beyond known limits. There are new things we’re uncovering every day where we go, “Oh, my God, I didn’t know we can do that with CO2!” So, that’s kind of fun.
Aaron: Can you tell me just a high-level overview of how CO2 extraction works?
Wes: A supercritical CO2 extraction system is a collection of extraction vessels and fractionation vessels or collection vessels. In our case fractionation because we’re doing multiple collections through a single run. Then you need a system of pumps and valves and tubing, etc. to move the solvent in a supercritical state through the packed biomass, and then move the extracted compounds into a set of collection vessels. It sounds very easy. But the key to supercritical CO2 extraction is controlling temperature, flow rate and pressure. The better you can control temperature, flow rate and pressure, the more precise of an outcome you’re going to get. For example, say you run a three-hour extraction run, and you want to run it at 3500 psi. Well, you know, a competitive system might fluctuate 300 to 400 psi on either side of 3500. Whereas our system currently fluctuates more like five to 10 psi on either side of the 3500. So, there is much more control and precision.
Our whole goal, when we’re talking about pushing CO2 beyond known limits, is how do we continue to chase that holy grail of perfect control of temperature, flow rate and pressure? One of our advances so far is a proprietary pump, for example, that’s a liquid displacement pump that we engineer and build. It ensures a very even and consistent flow, independent of the pressure setting. So, that flow rate doesn’t change in our system compared to what you would see with another system. It sounds like a minor thing, except that at the end of a run, if you expected to get a certain set of molecules, you’re going to get a different set of molecules if your temperature and flow rate and pressure are varying, because what you’re doing is disrupting the density of the CO2 as it flows.
It’s about building a system that is precise in that way, I think, that requires enormously skilled engineering effort and design effort on the front end, and then requires us to have advanced production and manufacturing capabilities in our shop in Pittsburgh. Our customers are clearly impressed with the levels of consistency that they’re getting out of their system.
Aaron: You talked about precision and consistency as two items. Is there anything else that makes Green Mill different?
Wes: I’m a brand guy. I believe in brands. I came out of a 20-year Coca-Cola career.
The way that the cannabis industry is going in total, in my opinion, is the consumer is going to get more and more discerning along the way. Up until this point, everybody thinks “oh, we have THC and CBD and we have intensity.” But the more sophisticated and educated consumers get, the more discerning they’re going to be about what products they want to put in their bodies.
What makes Green Mill different is that we’re building a system that allows the operator of that system to create differentiated products for the marketplace. So, it’s not simply “CBD is CBD.” It’s: what plant did you start with? How can you maintain as many of the characteristics of that plant as possible?
We’re going to create the most sophisticated tool possible to allow the operator to create products that can be differentiated in the marketplace for a discerning consumer at a premium price. That way, you can create a market where there might not have been a market before, instead of just “hey, I’ve got X pounds of biomass that I need to extract. Give me your bluntest instrument and let me extract.”
We currently make five different systems. First is the SFE Pro. We make a seven and a half liter and a 10-liter version, with two-vessel configurations of each of those. Then we have what we call a Parallel Pro, which has four 10-liter vessels and two pumps, with two streams running parallel to each other and emptying into shared collectors. It doubles the extraction rate, and you don’t expand the footprint very much. But 10-liter vessels are the biggest vessels we use. Because when you go too large with the vessel, you are giving up something in terms of the ability to control temperature, flow rate and pressure. Your efficiency starts to drop with higher vessel volume.
One of the things that makes Green Mill different is our extraction rate. Our Parallel Pro can do 145 pounds a day of biomass. We think that’s a significant amount, given the demand that’s out there for unique products. What we’re advocating for is multiple extraction systems instead of giant permanent installations of extraction systems, that end up limiting your flexibility. Big systems also prevent you from creating redundancies in your operating system. So, when your extraction system goes down, you’re done. Versus in our universe, we would say, you might want to have three or four extraction systems in different locations, running different products. Our price points are such that that’s very doable.
Aaron: How does the breakdown look between your cannabis and hemp clients?
Wes: A lot of that is legislative frankly. It has to do with what the environment is like at the moment. About 60% of our customers are small hemp farmers. And then we have the other 40% in the cannabis space that are medical or adult use producers.
CO2 extraction has a lot of applications beyond cannabis. We have a couple of customers using our system for hops extraction, for example. We see an enormous opportunity out there for non-cannabis botanical extraction, but our primary focus is cannabis. That is what we’re designing this system to do.
We find that small hemp farmers love our system because it is reliable and very automated. We have proprietary software that operates the whole system. You load and run various “recipes,” at least we call them recipes. What you are doing is setting flow rate, setting temperatures, setting pressures, etc., then that proprietary software has an unbelievable ability to control everything through the process. I’ve talked to several different operators who have used other machines, and then found themselves on a Green Mill system and couldn’t believe how easy, but also feature-rich it was.
I talk about it like it’s like an oven, you know, you set the oven at 375 degrees. And a really good oven stays right at 375. You still need to be a good chef to be able to make that perfect cheesecake. But without that oven, your hands are tied, so you are constantly trying to check those, “is it still 375? I don’t know!” With our system, if it says 375, it holds at 375. So we’re pretty excited about that.
And we’re going to continue to innovate. For example, we have a proprietary heat exchanger that we use on our systems. It’s actually 3D printed stainless steel. It’s about a 20-pound piece of steel that’s been printed to have a special tubing shape in the center only possible with 3D printing that allows us to heat CO₂ very quickly.
Aaron: That’s very cool. I’m noticing a lot actually, the innovations in cannabis are creating these adjacent market opportunities in botanicals. So, I think that’s interesting you point that out. You mentioned terpenes are one of the things you collect out of the CO2 extraction. Can you talk about the crude that comes off and how people are either monetizing or formulating that crude?
Wes: Our goal is to produce the “purest crude” possible. So, we want “less crude” crude. I think that we’re at the beginning of this, Aaron. We’re nowhere near the end, which is what I find so exciting, because all of our innovation, all of our continued development and all of our experimentation is designed to keep thinking, how do we push this further and further and further and get a more refined crude.
We just welcomed Jesse Turner to our team as Director of R&D, who is a well-known extraction guy in the industry. He came from Charlotte’s Web and Willie’s Reserve, and has been doing independent consulting. He’s just a rock star. He’s already off and running on experimenting with different stuff.
I think that we are just at the beginning of seeing more and more of that opportunity to help people realize, “Oh, my gosh, I did not know you could do this!” Terpenes are a good example. I think we are only scratching the surface of what terpenes can do. I mean, a cannabis plant has 400 plus molecules and we know a good bit about probably 10 or 12 of them. So, what are we going to find out about the other 390? And as we do, the Green Mill system will be ideal for separating those molecules that we don’t know today are valuable. So, I think that’s part of what we’re chasing as well.
Aaron: So where do you see CO2 extraction fitting into the cannabis and hemp supply chain?
Wes: For any product on the market that is not a smokable flower it helps to have an extraction process. There may be some products that come out that we don’t know about yet that are not going to qualify in that category. Whether you are talking about vape cartridges, or lozenges, or gummy bears, or whatever it is, they are going to start with extract. I think what consumers want is zero adulteration of their product. So if you take any botanical product, and if it is GMO-free, does not have any pesticides, maybe it is all organic, etc. — there is real consumer appeal to that. Whether you agree with it or not, it is what consumers want.
We believe that we can continue to push CO2 so that there’s no requirement for introduction of any other materials than just CO2, which is a completely inert gas. It’s got no residual effect whatsoever on the product. If we get where we want to go, then eventually you are talking about a pure botanical experience.
Initial upfront capital is higher than you are going to see with ethanol and butane extraction solutions for the same size equipment, but ongoing operating costs of those are much higher, when you weigh it out over a period of time. I think what we are going to find is that people are going to keep coming to CO2 because they realize there are things they can do with it that they can’t do any other way.
The end consumer is really who we want to keep in mind. I think for a long time, this industry was very demand driven. “I have X acres of cannabis product, whether that’s hemp, sativa, indica, whatever it is, and I need to extract this many pounds a day over this period of time.” And we keep asking the question, well, who’s going to buy that product on the other side? What do you want it to look like when you put it out on the market? As opposed to how much raw plant matter do you have? What’s the demand? And that was a difficult conversation. We’re starting to see more people come around to that conversation now. But I think that’s the question we want to keep answering is how do we create those products that are differentiated in the marketplace and that can pass muster in any regulatory environment? People are going to want to know what’s in their product.
Aaron: What trends are you following in the industry?
Wes: As the CEO, I’m particularly interested in the overall development of the landscape of the industry in terms of who’s playing, who’s winning, what’s happening with legislation, MSOs versus SSOs. I’m also interested in the international environment. We have a good bit of interest from multiple countries that have either ordered Green Mill systems or are talking to us about Green Mill systems, including Canada and Latin American countries, some European countries, Australia and New Zealand.“We’re really committed to educational efforts with a very rigorous scientific foundation, but in language that is approachable and people can understand.”
The trends that I’m particularly interested in are more on the business side of the equation, in terms of how this business is going to shake out particularly from a capitalization perspective, as banking laws continue to change, which is a big deal, and the legislative environment gets a little more predictable and a little more consistent.
Aaron: Okay, last question. So what are you personally interested in learning more about?
Wes: Everything, is the short answer! I constantly run this little challenge of trying to understand enough of the science. I’m not a scientist, I’m a sales guy. That was how I grew up: general management and sales. I’ve made my living over many years being wowed by the pros. Depending on the scientists and the very specialized folks to help provide the right answers to things. I’m fascinated by the chemistry and I’m fascinated by the mechanical engineering challenges of what we do at Green Mill. So, I’m always interested in learning about that.
I think there’s a need, and it is helpful to be able to talk about those things in language that the layperson can understand, as opposed to explaining everything in scientific language. I think what I am trying to do is help people put it into a language that they can get, but that is not simple. Language that is correlative to reality. I think there’s so much misunderstanding about how these things work and what’s happening. We’re really committed to educational efforts with a very rigorous scientific foundation, but in language that is approachable and people can understand.
Aaron: Okay, that’s it. Thank you for your time Wes!
Editor’s Note: The views expressed in this article are the author’s opinions based on his experience working in the laboratory industry. This is an opinion piece in a series of articles designed to highlight the potential problems that clients may run into with labs.
Do not be discouraged by the analytical jargon of the next few articles. I suggest that you go immediately to the conclusions to get the meat of this article and then read the rest of it to set you on the path to see the forest for the trees.
QC in a laboratory consists of a series of samples run by the laboratory to determine the accuracy and precision of a specific batch of samples. So, to start off, let’s look at the definitions of accuracy and precision.QC Charts can provide a detailed overview of laboratory performance in a well-run laboratory.
Accuracy: estimate of how close a measured value is to the true value; includes expressions for bias and precision.
Precision: a measure of the degree of agreement among replicate analyses of a sample.
A reputable laboratory will measure the Accuracy and Precision of QC samples in a batch of user samples and record these values in both the analytical test report issued to the user and in control charts kept by the laboratory. These control charts can be reviewed by the user if they are requested by the user. These control charts record:
Accuracy (means) chart: The accuracy chart for QC samples (e.g., LRB, CCV, LFBs, LFMs, and surrogates) is constructed from the average and standard deviation of a specified number of measurements of the analyte of interest.
Precision (range) chart: The precision chart also is constructed from the average and standard deviation of a specified number of measurements (e.g., %RSD or RPD) for replicate of duplicate analyses of the analyte of interest.
Now, let’s look at what should be run in a sample batch for cannabis analyses. The typical cannabis sample would have analyses for cannabinoids, terpenes, microbiological, organic compounds, pesticides and heavy metals.
Each compound listed above would require a specific validated analytical method for the type of matrix being analyzed. Examples of specific matrixes are:
Cannabis buds, leaves, oil
Edibles, such as Chocolates, Baked Goods, Gummies, Candies and Lozenges, etc.
Topicals, such as lotions, creams, etc.
Running QC analyses does not guarantee that the user’s specific sample in the batch was analyzed correctly.
Also, both ISO 17025-2005 and ISO 17025-2017 require the use of a validated method.
ISO 17025-2005: When it is necessary to use methods not covered by standard methods, these shall be subject to agreement with the customer and shall include a clear specification of the customer’s requirements and the purpose of the test and/or calibration. The method developed shall have been validated appropriately before use.
ISO 17025-2017: The laboratory shall validate non-standard methods, laboratory-developed methods and standard methods used outside their intended scope or otherwise modified. The validation shall be as extensive as is necessary to meet the needs of the given application or field of application.
The laboratory must have on file for user review the following minimum results in an analytical statistical report validating their method:
limit of quantitation,
precision,The user must look beyond the QC data provided in their analytical report or laboratory control charts.
linearity (or other calibration model),
confirmation of identity
limit of detection,
The interpretation of an analytical statistical report will be discussed in detail in the next article. Once the validated method has been selected for the specific matrix, then a sample batch is prepared for analysis.
Sample Batch: A sample batch is defined as a minimum of one (1) to a maximum of twenty (20) analytical samples run during a normal analyst’s daily shift. A LRB, LFB, LFM, LFMD, and CCV will be run with each sample batch. Failure of any QC sample in sample batch will require a corrective action and may require the sample batch to be reanalyzed. The definitions of the specific QC samples are described later.
The typical sample batch would be set as:
Instrument Start Up
Calibration Standards, Quadratic
Sample used for LFM/LFMD
Samples (First half of batch)
Samples (Second half of batch)
The QC samples are defined as:
Calibration Blank: A volume of reagent water acidified with the same acid matrix as in the calibration standards. The calibration blank is a zero standard and is used to calibrate the ammonia analyzer
Continuing Calibration Verification (CCV): A calibration standard, which is analyzed periodically to verify the accuracy of the existing calibration for those analytes.
Calibration Standard: A solution prepared from the dilution of stock standard solutions. These solutions are used to calibrate the instrument response with respect to analyte concentration
Laboratory Fortified Blank (LFB): An aliquot of reagent water or other blank matrix to which known quantities of the method analytes and all the preservation compounds are added. The LFB is processed and analyzed exactly like a sample, and its purpose is to determine whether the methodology is in control, and whether the laboratory is capable of making accurate and precise measurements.
Laboratory Fortified Sample Matrix/Duplicate (LFM/LFMD) also called Matrix Spike/Matrix Spike Duplicate (MS/MSD): An aliquot of an environmental sample to which known quantities of ammonia is added in the laboratory. The LFM is analyzed exactly like a sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical results. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the LFM corrected for background concentrations (Section 9.1.3).Laboratories must validate their methods.
Laboratory Reagent Blank (LRB): A volume of reagent water or other blank matrix that is processed exactly as a sample including exposure to all glassware, equipment, solvents and reagents, sample preservatives, surrogates and internal standards that are used in the extraction and analysis batches. The LRB is used to determine if the method analytes or other interferences are present in the laboratory environment, the reagents, or the apparatus.
Once a sample batch is completed, then some of the QC results are provided in the user’s analytical report and all of the QC results should be recorded in the control charts identified in the accuracy and precision section above.
But having created a batch and performing QC sample analyses, the validity of the user’s analytical results is still not guaranteed. Key conclusion points to consider are:
Laboratories must validate their methods.
Running QC analyses does not guarantee that the user’s specific sample in the batch was analyzed correctly.
QC Charts can provide a detailed overview of laboratory performance in a well-run laboratory.
The user must look beyond the QC data provided in their analytical report or laboratory control charts. Areas to look at will be covered in the next few articles in this series.
In the first part of this series, we spoke with Michelle Bradac, senior accreditation officer at A2LA, to learn the basics of cannabis laboratory accreditation. In the second part, we sat down with Roger Brauninger, A2LA Biosafety Program manager, to learn why states are looking to lab accreditation in their regulations for the cannabis industry. In the third part, we heard from Michael DeGregorio, chief executive officer of Konocti Analytics, Inc., discussing method development in the cannabis testing industry and his experience with getting accredited.
In the fourth and final part of this series, we sit down with Susan Audino, Ph.D., an A2LA lead assessor and instructor, laboratory consultant and board member for the Center for Research on Environmental Medicine in Maryland. Dr. Audino will share some insights into method validation and the most technical aspects of laboratory accreditation.
Susan Audino obtained her Ph.D. in Chemistry with an analytical chemistry major, physical and biochemistry minor areas. She currently owns and operates a consulting firm to service chemical and biological laboratories. Susan has been studying the chemistry and applications of cannabinoids and provides scientific and technical guidance to cannabis dispensaries, testing laboratories and medical personnel. Dr. Audino’s interest most directly involves cannabis consumer safety and protection, and promotes active research towards the development of official test methods specifically for the cannabis industry, and to advocate appropriate clinical research. In addition to serving on Expert Review Panels, she is also chairing the first Cannabis Advisory Panel and working group with AOAC International, is a member of the Executive Committee of the ASTM Cannabis Section and has consulted to numerous cannabis laboratories and state regulatory bodies.
CannabisIndustryJournal: What are the some of the most significant technical issues facing an accreditation body when assessing a cannabis-testing laboratory?
Susan: From the AB perspective, there needs to be a high level of expertise to evaluate the merits and scientific soundness of laboratory-developed analytical test methods. Because there are presently no standard or consensus test methods available, laboratories are required to develop their own methods, which need to be valid. Validating methods require a rigorous series of tests and statistical analyses to ensure the correctness and reliability of the laboratory’s product, which is– the test report.
CIJ: When is method validation required and how does this differ from system suitability?
Susan: Method validation is required whenever the laboratory modifies a currently accepted consensus or standard test method, or when the laboratory develops its own method. Method validation is characterized by a series of analytical performance criteria including determinations of accuracy, precision, linearity, specification, limit of detection, and limit of quantitation. The determination of system suitability requires a series of deliberate variations of parameters to ensure the complete system, that is all instrument(s) as well as the analytical method, is maintained throughout the entire analytical process. Traditionally, method validation has been referred to as “ruggedness” and system suitability as “robustness.”
CIJ: What are the most important aspects of method validation that must be taken into account?
Susan: In keeping with the FDA guidelines and other accepted criteria, I tend to recommend the International Conference on Harmonization (ICH), particularly Q 2A, which is a widely recognized program that discusses the pertinent characteristics of method validation. This include: method specification, linearity, range, accuracy, and precision (e.g., repeatability, intermediate precision, reproducibility). As mentioned earlier, system suitability is also a critical element and although related to method validation, does require its own protocol.
CIJ: What three areas do you see the laboratory having the hardest time with in preparing for accreditation?
Susan: My responses to this question assume the laboratory employs appropriate instruments to perform the necessary analyses, and that the laboratory employs personnel with experience and knowledge appropriate to develop test methods and interpret test results.
By and large, method validation that is not appropriate to the scope of their intended work. Driving this is an overall lack of information about method validation. Oftentimes there is an assumption that multiple recoveries of CRMs constitute “validation”. While it may be one element, this only demonstrates the instrument’s suitability. My recommendation is to utilize any one of a number of good single laboratory validation protocols. Options include, but are not limited to AOAC International, American Chemical Society, ASTM, and ICH protocols.
Second is the lack of statistically sound sampling protocols for those laboratories that are mandated by their governing states to go to the field to sample the product from required batches. Sampling protocols needs to address the heterogeneity of the plant, defining the batch, and determining/collecting a sample of sufficient quantity that will be both large enough and representative of the population, and to provide the laboratory an adequate amount from which to sub-sample.
Third, sample preparation. This is somewhat intertwined with my previous point. Once an appropriate sample has been collected, preparation must be relevant to the appropriate technology and assay. It is unlikely that a laboratory can perform a single preparation that is amenable to comprehensive testing.
Emerald Scientific’s Inter-Laboratory Comparison and Proficiency Test (ILC/PT) was recently approved in Washington as an official cannabis lab PT program, according to a press release. The Emerald Test program measures the accuracy of individual labs as well as comparing their results to other labs for indicators of variability and performance improvement.
Washington requires certified cannabis labs to participate in proficiency testing and Emerald Scientific’s tests is the only approved program in 4 out of 5 of the categories: potency, pesticide, heavy metals and residual solvent analysis. The most recent round of The Emerald Test showed broad improvements in many of the testing categories.
Perry Johnson, a third-party lab accreditation service for ISO/IEC 17025 also decided that The Emerald Test “meets the audit criteria for the proficiency test participation requirement for the accreditation,’ according to the press release. The proficiency test is a key component of quality assurance, which is a major requirement for labs seeking ISO 17025 accreditation. “The Emerald Scientific PT ensures that the cannabis testing labs are performing their function to the best of their ability,” says Reggie Gaudino Ph.D., vice president of Science, Genetics and Intellectual Property at Steep Hill Labs. “Any lab that isn’t participating and exceeding the minimal passing requirements should be viewed as suspect. It’s that important.”
According to the press release, Emerald Scientific’s spring 2017 program has expanded from 5 to 6 tests. The residual solvents and pesticide analysis portions offer more comprehensive testing that previously. “The other tests include 2 microbial panels and a Potency Test, which measures 5 cannabinoids including THC, THCA, CBD, CBDA, and CBN,” says the press release. “New this spring is the Heavy Metals Test, which is offered in 2 parts, one solution for cannabis heavy metals and the other in a hemp matrix.”
The Emerald Test advisory panel recently convened to review the results from the Fall 2016 round of the semi-annual Inter-Laboratory Comparison and Proficiency Test (ILC/PT), ahead of the third annual Emerald Conference just a few weeks away. After reviewing and analyzing the results, the panel noticed a significant improvement across the board over their Spring 2016 round of proficiency testing.
Emerald Scientific’s ILC/PT program is a tool laboratories use to check how accurate their testing capabilities are compared to other labs. A lab receiving The Emerald Test badge indicates their testing meets the criteria established by the panel to demonstrate competency. This means that they were within two standard deviations of the consensus mean for all analytes tested, according to Wes Burk, vice president of Emerald Scientific. He says the labs performed better than expected on both the microbial and pesticide tests.
Each lab has access to raw, anonymized data including a consensus mean, z-scores and kernel density plots. This round measured how well 35 cannabis labs perform in testing for potency, pesticides, residual solvents and microbial contaminants such as E. coli, Salmonella, Coliform, yeast and mold.
The advisory panel includes: Robert Martin, Ph.D., founder of CW Analytical, Cynthia Ludwig, director of technical services at AOCS, Rodger Voelker, Ph.D., lab director, OG Analytical, Tammie Mussitsch, QA manager at RJ Lee Group, Shawn Kassner, senior scientist at Neptune & Company, Inc., Jim Roe, scientific director at Steep Hill Labs, Chris Hudalla, Ph.D., founder and chief scientific officer at ProVerde Labs, Sytze Elzinga, The Werc Shop and Amanda Rigdon, Chief Technical Officer at Emerald Scientific.
According to Amanda Rigdon, chief technical officer at Emerald Scientific, the labs performed very well in potency, residual solvents and microbial testing PTs. This is the first year the proficiency testing includes pesticides. “All of the labs did a great job identifying every pesticide in our hemp-based PT, but some more work will most likely have to be done to bring quantitative results in line,” says Rigdon. “Since this was the first pesticide PT we had offered, we were pretty conservative when choosing analytes and their levels. For the most part, analytes and levels were taken from the Oregon pesticide list, which is widely recognized to be the most reasonable and applicable pesticide list out there to date.” They covered pesticides of high concern, like abamectin and Myclobutanil, but also included a wide range of other pesticides that labs are expected to encounter.
Shawn Kassner, senior scientist at Neptune & Company, Inc., believes microbial contamination proficiency testing should be a priority for improving public health and safety going forward. Although five participating labs did not receive badges for the microbial contamination PTs, panel members say the overall performance was really quite good. “Microbiology testing are essential analyses for all cannabis products and it’s just slower in regulatory implementation than potency testing,” says Kassner. “The risk of Salmonella and E. coli to an individual using a medical cannabis product could be very life threatening. Microbiology contamination is a huge concern for any public health agency, which is why we have seen that microbiology testing is usually the first analytical test required after potency.” Kassner notes that there were few outliers and with each Emerald PT program, he is seeing an improvement in overall laboratory performance.
For The Emerald Test’s next round, the panel hopes to make some improvements in the test’s robustness and consistency, like obtaining assigned values for all samples and comparing to a consensus mean. “We want to develop permanent badge criteria, streamline the appeals process and possibly implement a qualitative performance review in the pesticide PT,” says Burk. For the next round of pesticide PTs, they want to build a better list of pesticides to cover more states, allowing labs to pick a set based on their state’s regulations. Burk says they also want to collect data on whether or not matrix-matched curves were used for pesticides.
Rodger Voelker, Cynthia Ludwig and Shawn Kassner, all members of the advisory panel, will be speaking at the Emerald Conference, discussing some of their findings from this round of proficiency testing. The Emerald Conference will take place February 2nd and 3rd in San Diego, CA.
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