As mentioned in Part 1, the physiological effects of cannabis are mediated by a group of structurally related organic compounds known as cannabinoids. The cannabinoids are biosynthetically produced by a growing cannabis plant and Figure 1 details the biosynthetic pathways leading to some of the most important cannabinoids in plant material.
Figure 1: The biosynthetic pathway of phytocannabinoid production in cannabis has been deeply studied through isotopic labeling experiments
The analytical measurement of cannabinoids is important to ensure the safety and quality of cannabis as well as its extracts and edible formulations. Total cannabinoid levels can vary significantly between different cultivars and batches, from about 5% up to 20% or more by dry weight. Information on cannabinoid profiles can be used to tailor cultivars for specific effects and allows end users to select an appropriate dose.
Routine Analysisvs. Cannabinomics
Several structurally analogous groups of cannabinoids exist. In total, structures have been assigned for more than 70 unique phytocannabinoids as of 2005 and the burgeoning field of cannabinomics seeks to comprehensively measure these compounds.¹
Considering practical potency analysis, the vast majority of cannabinoid content is accounted for by 10-12 compounds. These include Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabigerol (CBG), Δ9-tetrahydrocannabivarian (THCV), cannabidivarin (CBDV) and their respective carboxylic acid forms. The cannabinoids occur primarily as carboxylic acids in plant material. Decarboxylation occurs when heat is applied through smoking, vaporization or cooking thereby producing neutral cannabinoids which are more physiologically active.
Potency Analysis by HPLC and GC
Currently, HPLC and GC are the two most commonly used techniques for potency analysis. In the case of GC, the heat used to vaporize the injected sample causes decarboxylation of the native cannabinoid acids. Derivatization of the acids may help reduce decarboxylation but overall this adds another layer of complexity to the analysis² ³. HPLC is the method of choice for direct analysis of cannabinoid profiles and this technique will be discussed further.
A sample preparation method consisting of grinding/homogenization and alcohol extraction is commonly used for cannabis flower and extracts. It has been shown to provide good recovery and precision² ³. An aliquot of the resulting extract can then be diluted with an HPLC compatible solvent such as 25% water / 75% acetonitrile with 0.1% formic acid. The cannabinoids are not particularly water soluble and can precipitate if the aqueous percentage is too high.
To avoid peak distortion and shifting retention times the diluent and initial mobile phase composition should be reasonably well matched. Another approach is to make a smaller injection (1-2 µL) of a more dissimilar solvent. The addition of formic acid or ammonium formate buffer acidifies the mobile phase and keeps the cannabinoid acids protonated.
The protonated acids are neutral and thus well retained on a C18 type column, even at higher (~50% or greater) concentrations of organic solvent² ³.
Detection is most often done using UV absorbance. Two main types of UV detectors are available for HPLC, single wavelength and diode array. A diode array detector (DAD) measures absorbance across a range of wavelengths producing a spectrum at each point in a chromatogram while single wavelength detectors only monitor absorbance at a single user selected wavelength. The DAD is more expensive, but very useful for detecting coelutions and interferences.
References
Chemical Constituents of Marijuana: The Complex Mixture of Natural Cannabinoids. Life Sciences, 78, (2005), pp. 539
Development and Validation of a Reliable and Robust Method for the Analysis of Cannabinoids and Terpenes in Cannabis. Journal of AOAC International, 98, (2015), pp. 1503
Innovative Development and Validation of an HPLC/DAD Method for the Qualitative and Quantitative Determination of Major Cannabinoids in Cannabis Plant Material. Journal of Chromatography B, 877, (2009), pp. 4115
Rebecca is an Applications Scientist at Restek Corporation and is eager to field any questions or comments on cannabis analysis, she can be reached by e-mail, rebecca.stevens@restek.com or by phone at 814-353-1300 (ext. 2154)
Almost as soon as cannabis became recreationally legal, the public started to ask questions about the safety of products being offered by dispensaries – especially in terms of pesticide contamination. As we can see from the multiple recalls of product there is a big problem with pesticides in cannabis that could pose a danger to consumers. While The Nerd Perspective is grounded firmly in science and fact, the purpose of this column is to share my insights into the cannabis industry based on my years of experience with multiple regulated industries with the goal of helping the cannabis industry mature using lessons learned from other established markets. In this article, we’ll take a look at some unique challenges facing cannabis testing labs, what they’re doing to respond to the challenges, and how that can affect the cannabis industry as a whole.
Photo: Michelle Tribe, Flickr
The Big Challenge
Over the past several years, laboratories have quickly ‘grown up’ in terms of technology and expertise, improving their methods for pesticide detection to improve data quality and lower detection limits, which ultimately ensures a safer product by improving identification of contaminated product. But even though cannabis laboratories are maturing, they’re maturing in an environment far different than labs from regulated industry, like food laboratories. Food safety testing laboratories have been governmentally regulated and funded from almost the very beginning, allowing them some financial breathing room to set up their operation, and ensuring they won’t be penalized for failing samples. In contrast, testing fees for cannabis labs are paid for by growers and producers – many of whom are just starting their own business and short of cash. This creates fierce competition between cannabis laboratories in terms of testing cost and turnaround time. One similarity that the cannabis industry shares with the food industry is consumer and regulatory demand for safe product. This demand requires laboratories to invest in instrumentation and personnel to ensure generation of quality data. In short, the two major demands placed on cannabis laboratories are low cost and scientific excellence. As a chemist with years of experience, scientific excellence isn’t cheap, thus cannabis laboratories are stuck between a rock and a hard place and are feeling the squeeze.
Responding to the Challenge
One way for high-quality laboratories to win business is to tout their investment in technology and the sophistication of their methods; they’re selling their science, a practice I stand behind completely. However, due to the fierce competition between labs, some laboratories have oversold their science by using terms like ‘lethal’ or ‘toxic’ juxtaposed with vague statements regarding the discovery of pesticides in cannabis using the highly technical methods that they offer. This juxtaposition can then be reinforced by overstating the importance of ultra-low detection levels outside of any regulatory context. For example, a claim stating that detecting pesticides at the parts per trillion level (ppt) will better ensure consumer safety than methods run by other labs that only detect pesticides at concentrations at parts per billion (ppb) concentrations is a potentially dangerous claim in that it could cause future problems for the cannabis industry as a whole. In short, while accurately identifying contaminated samples versus clean samples is indeed a good thing, sometimes less isn’t more, bringing us to the second half of the title of this article.
Less isn’t always more…
The Milky Way
In my last article, I illustrated the concept of the trace concentrations laboratories detect, finishing up with putting the concept of ppb into perspective. I wasn’t even going to try to illustrate parts per trillion. Parts per trillion is one thousand times less concentrated than parts per billion. To put ppt into perspective, we can’t work with water like I did in my previous article; we have to channel Neil deGrasse Tyson.
The Milky Way galaxy contains about 100 billion stars, and our sun is one of them. Our lonely sun, in the vastness of our galaxy, where light itself takes 100,000 years to traverse, represents a concentration of 10 ppt. On the surface, detecting galactically-low levels of contaminants sounds wonderful. Pesticides are indeed lethal chemicals, and their byproducts are often lethal or carcinogenic as well. From the consumer perspective, we want everything we put in our bodies free of harmful chemicals. Looking at consumer products from The Nerd Perspective, however, the previous sentence changes quite a bit. To be clear, nobody – nerds included – wants food or medicine that will poison them. But let’s explore the gap between ‘poison’ and ‘reality’, and why that gap matters.
In reality, according to a study conducted by the FDA in 2011, roughly 37.5% of the food we consume every day – including meat, fish, and grains – is contaminated with pesticides. Is that a good thing? No, of course it isn’t. It’s not ideal to put anything into our bodies that has been contaminated with the byproducts of human habitation. However, the FDA, EPA, and other governmental agencies have worked for decades on toxicological, ecological, and environmental studies devoted to determining what levels of these toxic chemicals actually have the potential to cause harm to humans. Rather than discuss whether or not any level is acceptable, let’s take it on principle that we won’t drop over dead from a lethal dose of pesticides after eating a salad and instead take a look at the levels the FDA deem ‘acceptable’ for food products. In their 2011 study, the FDA states that “Tolerance levels generally range from 0.1 to 50 parts per million (ppm). Residues present at 0.01 ppm and above are usually measurable; however, for individual pesticides, this limit may range from 0.005 to 1 ppm.” Putting those terms into parts per trillion means that most tolerable levels range from 100,000 to 50,000,000 ppt and the lower limit of ‘usually measurable’ is 10,000 ppt. For the food we eat and feed to our children, levels in parts per trillion are not even discussed because they’re not relevant.
A specific example of this is arsenic. Everyone knows arsenic is very toxic. However, trace levels of arsenic naturally occur in the environment, and until 2004, arsenic was widely used to protect pressure-treated wood from termite damage. Because of the use of arsenic on wood and other arsenic containing pesticides, much of our soil and water now contains some arsenic, which ends up in apples and other produce. These apples get turned into juice, which is freely given to toddlers everywhere. Why, then, has there not an infant mortality catastrophe? Because even though the arsenic was there (and still is), it wasn’t present at levels that were harmful. In 2013, the FDA published draft guidance stating that the permissible level of arsenic in apple juice was 10 parts per billion (ppb) – 10,000 parts per trillion. None of us would think twice about offering apple juice to our child, and we don’t have to…because the dose makes the poison.
How Does This Relate to the Cannabis Industry?
The concept of permissible exposure levels (a.k.a. maximum residue limits) is an important concept that’s understood by laboratories, but is not always considered by the public and the regulators tasked with ensuring cannabis consumer safety. As scientists, it is our job not to misrepresent the impact of our methods or the danger of cannabis contaminants. We cannot understate the danger of these toxins, nor should we overstate their danger. In overstating the danger of these toxins, we indirectly pressure regulators to establish ridiculously low limits for contaminants. Lower limits always require the use of newer testing technologies, higher levels of technical expertise, and more complicated methods. All of this translates to increased testing costs – costs that are then passed on to growers, producers, and consumers. I don’t envy the regulators in the cannabis industry. Like the labs in the cannabis industry, they’re also stuck between a rock and a hard place: stuck between consumers demanding a safe product and producers demanding low-cost testing. As scientists, let’s help them out by focusing our discussion on the real consumer safety issues that are present in this market.
*average of domestic food (39.5% contaminated) and imported food (35.5% contaminated)
When a cannabis sample is submitted to a lab for testing there is a four-step process that occurs before it is tested in the instrumentation on site:
It is ground at a low temperature into a fine powder;
A solution is added to the ground powder;
An extraction is repeated 6 times to ensure all cannabinoids are transferred into a common solution to be used in testing instrumentation.
Once the cannabinoid solution is extracted from the plant matter, it is analyzed using High Pressure Liquid Chromatograph (HPLC). HPLC is the key piece of instrumentation in cannabis potency testing procedures.
While there are many ways to test cannabis potency, HPLC is the most widely accepted and recognized testing instrumentation. Other instrument techniques include gas chromatography (GC) and thin layer chromatography (TLC). HPLC is preferred over GC because it does not apply heat in the testing process and cannabinoids can then be measured in their naturally occurring forms. Using a GC, heat is applied as part of the testing process and cannabinoids such as THCA or CBDA can change form, depending on the level of heat applied. CBDA and THCA have been observed to change form at as low as 40-50C. GC uses anywhere between 150-200C for its processes, and if using a GC, a change of compound form can occur. Using HPLC free of any high-heat environments, acidic (CBDA & THCA) and neutral cannabinoids (CBD, THC, CBG, CBN and others) can be differentiated in a sample for quantification purposes.
Near Infrared
Near infrared (NIR) has been used with cannabis for rapid identification of active pharmaceutical ingredients by measuring how much light different substances reflect. Cannabis is typically composed of 5-30% cannabinoids (mainly THC and CBD) and 5-15% water. Cannabinoid content can vary by over 5% (e.g. 13-18%) on a single plant, and even more if grown indoors. Multiple NIR measurements can be cost effective for R&D purposes. NIR does not use solvents and has a speed advantage of at least 50 times over traditional methods.
The main downfall of NIR techniques is that they are generally less accurate than HPLC or GC for potency analyses. NIR can be programmed to detect different compounds. To obtain accuracy in its detection methods, samples must be tested by HPLC on ongoing basis. 100 samples or more will provide enough information to improve an NIR software’s accuracy if it is programmed by the manufacturer or user using chemometrics. Chemometrics sorts through the often complex and broad overlapping NIR absorption.
Bands from the chemical, physical, and structural properties of all species present in a sample that influences the measured spectra. Any variation however of a strain tested or water quantity observed can affect the received results. Consistency is the key to obtaining precision with NIR equipment programming. The downfall of the NIR technique is that it must constantly be compared to HPLC data to ensure accuracy.
At Eurofins Experchem , our company works with bothHPLC and NIR equipment simultaneously for different cannabis testing purposes. Running both equipment simultaneously means we are able to continually monitor the accuracy of our NIR equipment as compared to our HPLC. If a company is using NIR alone however, it can be more difficult to maintain the equipment’s accuracy without on-going monitoring.
What about Terpenes?
Terpenes are the primary aromatic constituents of cannabis resin and essential oils. Terpene compounds vary in type and concentration among different genetic lineages of cannabis and have been shown to modulate and modify the therapeutic and psychoactive effects of cannabinoids. Terpenes can be analyzed using different methods including separation by GC or HPLC and identification by Mass Spectrometry. The high-heat environment for GC analysis can again cause problems in accuracy and interpretation of results for terpenes; high-heat environments can degrade terpenes and make them difficult to find in accurate form. We find HPLC is the best instrument to test for terpenes and can now test for six of the key terpene profiles including a-Pinene, Caryophyllene, Limonene, Myrcene, B-Pinene and Terpineol.
Quality Systems
Quality systems between different labs are never one and the same. Some labs are testing cannabis under good manufacturing practices (GMP), others follow ISO accreditation and some labs have no accreditation at all.
From a quality systems’ perspective some labs have zero or only one quality system employee(s). In a GMP lab, to meet the requirements of Health Canada and the FDA, our operations are staffed in a 1:4 quality assurance to analyst ratio. GMP labs have stringent quality standards that set them apart from other labs testing cannabis. Quality standards we work with include, but are not limited to: monthly internal blind audits, extensive GMP training, yearly exams and ongoing tests demonstrating competencies.
Maintaining and adhering to strict quality standards necessary for a Drug Establishment License for pharmaceutical testing ensures accuracy of results in cannabis testing otherwise difficult to find in the testing marketplace.
Important things to know about testing
HPLC is the most recommended instrument used for product release in a regulated environment.
NIR is the best instrument to use for monitoring growth and curing processes for R&D purposes, only if validated with an HPLC on an ongoing basis.
Quality Systems between labs are different. Regardless of instrumentation used, if quality systems are not in place and maintained, integrity of results may be compromised.
GMPs comprise 25% of our labour costs to our quality department. Quality systems necessary for a GMP environment include internal audits, out of specification investigations, qualification and maintenance of instruments, systems controls and stringent data integrity standards.
Dr. Zacariah Hildenbrand, chief scientific officer and partner at C4 Laboratories, is currently researching some of the lesser-known molecules in cannabis, and he’s on to something. His research focuses on discovering new molecules, determining their therapeutic effects and expanding our understanding of the constituents of cannabis.
Dr. Zacariah Hildenbrand, chief scientific officer and partner at C4 Laboratories.
Dr. Hildenbrand received his Ph.D. from the University of Texas at El Paso where he researched the molecular architecture involved in hormone-dependent cancers. At the University of Texas Southwestern Medical Center in Dallas, his post-doctoral research contributed to the development of a novel therapy for the treatment of chronic myeloid leukemia, a blood-borne cancer that afflicts small children. He has published over 25 peer-reviewed scientific journal articles and hopes to do the same with his research in cannabis.
After a career of scientific consulting, Dr. Hildenbrand met Ryan Treacy, founder and chief executive officer of C4 Laboratories, in 2015 when Treacy launched the company. In June of 2015, the laboratory began operations, providing Dr. Hildenbrand the opportunity to embark on a new and exciting field of research- cannabis.
Ryan Treacy, founder and chief executive officer at C4 Laboratories.
They currently collaborate with Dr. Kevin Schug of the Shimadzu Center for Advanced Analytical Chemistry (SCAAC) at the University of Texas, Arlington and together Drs. Schug and Hildenbrand are pursuing a DEA license to expand their current cannabis research. The SCAAC is a $10.0+ million analytical laboratory with instrumentation that only a handful of people in the world has access to.
C4 Laboratories, based in Mesa, Arizona, currently offers a range of services for cannabis analysis including terpene and cannabinoid analytics, microbial, pesticide, fungicide and insecticide testing. In addition to the standard gamut of tests, they also specialize in cultivation analytics like mold and mildew culture testing, viral detection with sentinel plants and comprehensive analysis of environmental conditions.
What makes their company unique is their multidisciplinary effort to characterize the therapeutic compounds found in cannabis, the C4 Cannabinomics Collaborative. We sit down with Dr. Zac Hildenbrand to talk cannabis science, his research and what they hope to accomplish with the C4 Cannabinomics Collaborative.
CannabisIndustryJournal: What is the C4 Cannabinomics Collaborative?
Dr. Zacariah Hildenbrand: The C4 Cannabinomics Collaborative is an open collaboration between growers and scientists to discover new molecules in cannabis and to have a better characterization of individual cannabis strains based on the active constituents found in each sample. We are facilitating the collaboration of some of the world’s best cannabis growers with world-class scientists to find new information about the plant.
What we want to accomplish in this work is identifying novel molecules. Because of the [federal government’s] restrictions in researching cannabis, there is very little peer-reviewed literature on many of the compounds found in cannabis. We want to secondarily find out what those molecules do in the human body and thus make recommendations for strains targeting specific conditions.
We also want to understand the strains currently out there by determining the most established cannabinoids and terpenes via chemotyping. You hear a lot of people talking about the effects of an Indica or Sativa and making recommendations based on that. We want to find chemical signatures based on cannabinoids and terpenes and make recommendations based on that. There are a lot of problems at hand when discussing strain names scientifically. There are nomenclature issues- people calling the same strain different names, people giving multiple names to the same strain to make it appear that their strain portfolios are more diverse.
We can identify the chemical signatures in strains based on the major cannabinoids and terpenes. Based on the terpenes and chemical profile we can determine more accurate recommendations for patients as well as in recreational applications. All of this, again, discovering the new molecules, identifying the current strains, is so we can make more informed decisions regarding cannabis use. It is not a panacea but it is a very robust plant. There are a lot of terpenes with anti-inflammatory responses. Other molecules help with blood flow, sleep, regulating blood glucose, and we all know the cases of CBD helping children with convulsions and epilepsy. We want people to make sure they have the most up-to-date information.
CIJ: How is your collaboration with the SCAAC at UT Arlington contributing to this work?
Dr. Hildenbrand: One of the instruments we use there is a supercritical-fluid-extraction supercritical-fluid-chromatography mass-spectrometer (SFE-SFC-MS). With that instrument, we can do the extraction on the machine with an extreme level of sensitivity. It is ideal for drug discovery and identifying molecules in the parts-per-quadrillion range. This particular instrument allows us to detect molecules with an extreme level of sensitivity without volatizing them during the sample extraction process.
The Shimadzu Center for Advanced Analytical Chemistry
We want to acquire samples of unique cannabis from growers that will work with us to discover new cannabis constituents. We are in the process of getting a DEA license so that we can send products across state lines to the center at UT Arlington to perform the advanced characterization. They have instrumentation that only a handful of people in the world have access to, which gives us the best opportunity to explore the unknown. When we discover new molecules, find out what they do on the molecular level, we can then isolate these compounds and ultimately use this newfound knowledge for the development of effective nutraceuticals.
CIJ: What molecules are you researching right now?
Dr. Hildenbrand: Some of the low-hanging fruit in our research looks at identifying compounds similar to the better-studied compounds such as THC and CBD. THCV has a very similar structure to THC, but has a shorter acyl carbon chain (3 carbons vs. 5).
Tetrahydrocannabivarin (THCV)
THCV doesn’t induce a psychoactive response (like THC), but it does improve fat utilization, so it has remarkable potential for medicine. We are looking at what conditions are required for it to occur naturally. Cannabis doesn’t produce THCV in a high amount. 0.7% by weight is the most we have seen in Arizona. In Oregon, where craft cannabis has been refined to a much higher degree, we have heard rumblings of some strains containing up to 3% THCV. We want to find out if this is a possible weight loss tool. Our research in CBDV is very much the same.
CBL is the breakdown product of CBC when it is treated with ultraviolet light. We know absolutely nothing about what CBL does. If we find a strain that produces high amounts of CBC, we can then treat it with UV light and force the conversion to CBL, and then ultimately determine what it does. This is a good example of low-hanging fruit and the versatility of cannabis. Based on the biogenesis of the cannabinoids, we can alter the profile of cannabis products using a series of biochemical reactions.
Cannabicyclol (CBL)
For example, we have been helping clients in Arizona look for a quality sleep aid in cannabis. Certainly, Indica strains will help, but the molecule CBN helps specifically with sleep abnormalities. As CBN is formed as a byproduct when CBD or THC are oxidized, we see some producers using liquid nitrogen to oxidize CBD, leading to higher CBN levels. I would like to think we are in the age of understanding CBD, THC and the major terpenes,but there are a whole milieu of compounds that require our attention and THCV, CBDV and CBL are just a few that we want to devote our efforts to right away.
CIJ: What are your plans in the immediate future?
Dr. Hildenbrand: We are in the process of finalizing the documents to bring a C4 laboratory into Oregon where we can do quite a bit of research and where we’ll have access to some very unique cannabis. We will offer full compliance testing per ORELAP and OLCC regulations, but we also want to acquire samples (free of charge) from growers that want to collaborate with us to discover new molecules. We’ve been lucky enough to start working with growers like Adam Jacques and Chris West in Eugene, but we also want to be available to other growers who want to contribute to this research.
CIJ: What are your long-term goals with this project?
Dr. Hildenbrand: At a basic level, we hope to expand the current understanding of the cannabis plant. There is a lot of “bro science” and anecdotal claims out there. There is so much that we don’t know about cannabis that we cannot simply rely on anecdotal claims for each strain. We want to bring cannabis into the same light as any pharmaceutical-grade or biomedical research.
We need to be characterizing this plant with the same level of detail as other pertinent molecular therapies. In doing so there are a lot of potential discoveries to be made and we might be able to unlock the future of medicine. A drug like Marinol, for example, has been met with mixed reviews because its only one dimensional. Furthermore, we find that the terpene molecules are tremendously beneficial and this interplay between cannabinoids and terpenes is something that we want to explore further. All and all we wish to further illustrate the therapeutic capacities of cannabis within the contexts of specific ailments and medical conditions, while discovering the medicine of the future.
Three health alerts were issued Thursday, November 4th for contaminated cannabis sold to consumers at North Bend, Salem and Eugene dispensaries. Green-Way Medicinal in Salem and Stonies in North Bend sold two strains of cannabis flower found to have high levels of piperonyl butoxide, an ingredient commonly found in pesticides that acts as a synergist to amplify the effects of certain compounds.
The two batches in question, including the strains Pleeze (batch number G6J0039-02) and Dryzl (batch number G6J0039-01), were found to contain the potentially dangerous chemical at levels of 15.39 ppm and 16.24 ppm, respectively. The Oregon Health Authority (OHA) action level for piperonyl butoxide is 2.0 ppm. To see the full health alert, click here.
The dispensary in Eugene, Flowr of Lyfe, sold one strain of cannabis that had levels of the insecticide spinosad over the 0.2-ppm action level. The very popular indica hybrid, Dutch Treat (batch number G6J0018-01), was found to contain 0.9-ppm of spinosad. Though it still tested above the 0.2-ppm action level for that insecticide, it pales in comparison to October’s health alert, where a batch of cannabis had over 200 times the acceptable level of that insecticide. Both spinosad and piperonyl butoxide are considered toxic to humans.
According to the health alert, “All tests were performed by an OHA-accredited and Oregon Liquor Control Commission-licensed laboratory.” It is unclear exactly how or why the cannabis was able to get transported and transferred from the grower to the dispensary and then sold to consumers after failing the pesticide test. According to Jonathan Modie, spokesman for the OHA, they are currently investigating the matter and following up with the dispensaries and growers to find out what happened. “We need to find out how this got transferred in the first place and then sold,” says Modie. “They had access to the test results and should have been able to determine for themselves that these products should not have been sold or transferred.”
“We don’t know, we are still gathering information, there is a risk of civil penalty as well as losing your registration for a dispensary or grower that illegally transferred products that have tested for analytes above the action levels,” says Modie, when asked if punitive measures would be taken. While there are no particular regulations for this scenario in performing a mandatory recall, the OHA is obligated under law to issue health alerts when there is a situation that might affect public health, according to Modie.
“We deal with this with infectious disease outbreaks or during a food borne illness outbreak; if they [the public] can avoid it by hearing from us then we want to get the word out and this is a very similar situation.” For medical patients that purchase potentially contaminated cannabis such as this, it is easy to contact them to have the patient dispose or return the cannabis. Dispensaries are not required to collect information from recreational customers, and most dispensaries do not, which is a major problem when this situation happens, as it has twice in the past two weeks.
“We can never do too much communication,” says Modie. “We will let the public know in any way possible that they should return this product or dispose of it responsibly.”
In the last article I referred to the analogy of the analytical reference material being a keystone of the laboratory foundation, the stone upon which all data relies. I then described the types of reference materials and their use in analytical testing in general terms. This article will describe the steps required to properly manufacture and deliver a certified reference material (CRM) along with the necessary documentation.
A CRM is an exclusive reference material that meets strict criteria defined by ISO Guide 34 and ISO/IEC 17025. ISO is the International Organization for Standardization and IEC is the International Electrotechnical Commission. These organizations work together to set globally recognized standards. In order for a reference material to be labeled as a CRM it must 1) be made with raw or starting materials which are characterized using qualified methods and instruments, 2) be produced in an ISO-accredited lab under documented procedures, and 3) fall under the manufacturer’s scopes of accreditation. Verifying a CRM supplier has these credentials is easily done by viewing their certificates which should include their scopes of accreditation.
There are many steps required to produce a CRM that meets the above three criteria. The first step requires a review of the customer’s, or end-user’s requirements to carefully define what is to be tested, at what levels and which analytical workflow will be used. Such information enables the producer to identify the proper compounds and solvents required to properly formulate the requested CRM.
The next step requires sourcing and acquiring the raw, or starting materials, then verifying their compatibility and stability using stability and shipping studies in accordance with ISO requirements. Next the chemical identify and purity of the raw materials must be characterized using one or more analytical techniques such as: GC-FID, HPLC, GC-ECD, GC-MS, LC-MS, refractive index and melting point. In some cases, the percent purity is changed by the producer when their testing verifies it’s different from the supplier label. All steps are of course documented.
The producer’s analytical balances must be verified using NIST traceable weights and calibrated annually by an accredited third party provider to guarantee accurate measurement. CRMs must be prepared using Class A volumetric glassware, and all ampules and vials used in preparation and final packaging must be chemically treated to prevent compound degradation during storage. Next, CRMs are packaged in an appropriate container, labeled then properly stored to maintain the quality and stability until it’s ready to be shipped. All labels must include critical storage, safety and shelf life information to meet federal requirements. The label information must be properly linked to documentation commonly referred to as a certificate of analysis (COA) which describes all of the above steps and verifies the traceability and uncertainty of all measurements for each compound contained in the CRM.
My company, RESTEK, offers a variety of documentation choices to accompany each CRM. Depending on the intended use and data quality objectives specified by the end-user, which were defined way back at the first step, three options are typically offered: They include gravimetric only, qualitative which includes gravimetric, and fully quantitative which includes all three levels of documentation. The graphic to the right summarizes the three options and what they include.
It’s important to understand which level you’re purchasing especially when ordering a custom CRM from a supplier. Most stock CRMs include all three levels of documentation, but it’s important to be sure.
Understanding what must be done to produce and deliver a CRM sets it apart from other reference material types, however it’s important to understand there are some instances where CRMs are either not available, nor required and in those situations other types of reference materials are perfectly acceptable.
If you have any questions or would like more details about reference materials please contact me, Joe Konschnik at (800) 356-1688 ext. 2002 by phone, or email me at joe.konschnik@restek.com.
According to Jonathan Modie, spokesman for the Oregon Health Authority (OHA), on Friday, October 21st, the OHA issued a ‘health alert’ regarding cannabis products sold from a McMinnville dispensary that were possibly tainted with extremely high levels of Spinosad, an insecticide commonly used to combat mites and other pests. “My understanding is that two medical patients purchased the cannabis products whom we had contact info for, but most of the purchasers were recreational customers,” says Modie. “Because it is not required to get contact info for recreational customers, we issued the health alert to get the word out as quickly as possible because we didn’t know who bought the product.” The OHA is urging consumers who purchased cannabis from New Leaf CannaCenter in McMinnville to check the labels and see if they purchased potentially dangerous cannabis, and to either return the cannabis to the dispensary or dispose of it appropriately.
The action level, the measured amount of pesticides in a product that the OHA deems potentially dangerous, for Spinosad is 0.2 parts-per-million (PPM). The two batches in question are the strains Dr. Jack (batch number G6J0051-02) and Marion Berry (batch number G6J0051-01), which were tested to contain approximately 42 PPM and 22 PPM respectively, much higher than the OHA’s action level.
While this is the first health alert issued in Oregon in connection with potentially contaminated cannabis, Modie says he expects there will be more health alerts in the future. “Unfortunately the product was inappropriately transferred from the grower to the dispensary and from the dispensary to customers, so we are working to get the word out to dispensaries, growers and processors about the testing rules to prevent this from happening in the future,” says Modie. “We want to make it clear that any grower, processor or dispensary that does not follow the testing requirements or fail to label, store or retain batches that fail a test will be subject to enforcement actions such as fines, penalties, suspension or revocation of their license.” The OHA has a list of pesticide analytes and their action levels on their website.
“We are advising recreational and medical users alike to read the product labels closely; the labels must have the license or registrant number, the packaging or distributor license number, the name of the strain and the universal symbol,” says Modie. “We are also suggesting consumers request a copy of pesticide test results from the dispensary.” It is unclear at this time if all of the cannabis products in question have been properly disposed of, but OHA was informed that New Leaf has pulled all products in question off of the shelf.
Last week, Steep Hill Labs, Inc. announced plans to expand on the East Coast, including licensing for laboratories in Washington, D.C. and Pennsylvania. The cannabis testing company now is operating or developing in seven states, the District of Columbia along with an official arrangement with a research university in Jamaica, according to Cathie Bennett Warner, director of public relations at Steep Hill.
The same team of physicians that oversees the Steep Hill laboratory in Maryland will operate the Pennsylvania and D.C. labs. Heading that team is chief executive officer Dr. Andrew Rosenstein, chief of the division of Gastroenterology at University of Maryland Saint Joseph Medical Center and assistant clinical professor of Gastroenterology and Hepatology at the University of Maryland Medical Center. Dr. Rosenstein has been recognized by Baltimore Magazine as a top doctor in the Baltimore area, according to a press release.
Dr. Andrew Rosenstein, CEO of Steep Hill Maryland, PA and D.C.
According to Dr. Rosenstein, they want to provide accurate clinical results for trials with patients using cannabis. “All clinical trials will require a competent, credible and reliable lab partner and that is what we are bringing to the field- and that is why we are working with Steep Hill,” says Dr. Rosenstein. With team members having backgrounds in pathology, molecular diagnostics, clinical chemistry, microbiology and genetics, it should come as no surprise that they plan to participate in clinical research.
Dr. Rosenstein’s vested interest in cannabis safety stems from prior experience with his patients using cannabis. “Over the past five years, we have seen an increased number of patients using cannabis, particularly for managing the side effects of Crohn’s disease and cancer treatment,” says Dr. Rosenstein. “They would bring it up to us and at the time I didn’t know much about it, but anecdotally it’s really clear that a lot of patients have great responses to it.” Not knowing much about the preparation or safety of cannabis at the time led Dr. Rosenstein to advise patients to be very careful if they are immunocompromised.
Examination of cannabis prior to testing- credit: Steep Hill Labs, Inc.
“When a patient is immunocompromised, a bacterial or fungal infection can be lethal, so because we had patients using cannabis, we wanted to make sure it was safe,” says Dr. Rosenstein. So when Maryland legalized medical cannabis, Dr. Rosenstein and his team saw the need to protect patient safety and Steep Hill was a perfect fit. “We really didn’t want to reinvent the wheel so we looked for someone to partner with,” says Dr. Rosenstein. “Steep Hill has the best technology and the best credibility and we didn’t want to compromise on quality and safety issues. They felt the same way so we partnered with them and culturally it has been a great fit.”
Steep Hill Express in Berkeley, CA- MD,PA and D.C. will have a similar offering of instant potency analysis
The new laboratories plan to offer a similar range of services that are offered at other Steep Hill labs, such as rapid potency testing for THC-A, ∆-9-THC, CBD, CBD-A and moisture. But Dr. Rosenstein sees clinical opportunities in the East Coast medical hubs. “We want to provide the testing component for studies, providing clinical reproducibility and consistency, and those are the things as a top-notch lab that we are interested in doing.”
A petri dish of mold growth from tested cannabis- Photo credit: Steep Hill Labs, Inc.
With a physician-led group that has experience in molecular diagnostics, partnering with Steep Hill is about being medically focused, according to Dr. Rosenstein. “First and foremost, this is about patient safety.” Because of that, he emphasizes the need for required microbiological contaminant testing, particularly because of his experience with patients. “If you’re a cancer patient and you get a toxic dose of salmonella or E. coli, that can kill you, so testing for microbiologic contamination is of the highest priority.”
According to Warner, bridging the medical cannabis science gap with Steep Hill’s professionalism and experienced doctors practicing medicine is a big deal. “We are working very closely with their medical team to make sure these standards are medically superior,” says Warner. “To have these doctors with such a high level of knowledge in medicine working with us in cannabis analytics is a breakthrough.”
In my last column, I took a refreshing step out of the weeds of the specifics behind cannabis analyses and took a broader, less technical look at the cannabis industry. I had envisioned The Nerd Perspective being filled with profound insights that I have had in the cannabis industry, but I have realized that if I restricted this column to insights most would consider profound…well…there would not be many articles. So in this article, I want to share an insight with you, but not one that is earth shattering. Instead, I want to talk about a simple concept in a way that might help you think a little differently about the results your lab generates, the results you have to pay for or even the results printed on a cannabis product you might purchase.
This article is all about the simple concept of concentration – the expression of how much of something there is in relation to something else. We use expressions of concentration all the time – calories per serving, percent alcohol in beer, even poll results in the presidential election circus. Cannabis is not excluded from our flippant use of concentration terms – percent cannabinoid content, parts-per-million (ppm) residual solvents, and parts-per-billion (ppb) pesticides. Most of us know the definition of percent, ppm, and ppb, and we use these terms all the time when discussing cannabis analytical methods. During my career in analytical chemistry, it has occurred to me that parts per billion is a really infinitesimal amount…I know that intellectually, but I have never tried to actually visualize it. So being the nerd that I am, I went about comparing these often-used concentration terms visually in my kitchen.
I started by preparing a 1% solution of food coloring paste in water. This was accomplished by weighing out 5g of the food coloring and dissolving it into 500mL of water (about one teaspoon into a pint). The resulting solution was so dark it was almost black:
The picture above expresses the low end of what we care about in terms of cannabinoid concentration and a pretty normal value for a high-concentration terpene in cannabis.
I then took one teaspoon of that mixture and dissolved it into 1.32 gallons of water (5mL into 5000mL), resulting in a 10ppm solution of green food coloring in water:
I did not expect the resulting solution to be so light colored given the almost-black starting solution, but I did dilute the solution one thousand times. To put this into perspective, 10ppm is well above many state regulatory levels for benzene in a cannabis concentrate.
I then took one teaspoon of the almost-colorless 10ppm solution and dissolved that into another 1.32 gallons of water, resulting in a very boring-looking 10ppb solution of green food coloring in water:
Obviously, since I diluted the almost-colorless 10ppm solution a thousand times, the green food coloring cannot be seen in the picture above. As a reference, 10ppb is on the low end of some regulations for pesticides in food matrices, including – possibly – cannabis. I know the above picture is not really very compelling, so let’s think in terms of mass. The picture above shows eleven pounds of water. That eleven pounds of water contains 50 micrograms of food coloring…the weight of a single grain of sand.
To expand on the mass idea, let’s take a look at the total mass of cannabis sold legally in Colorado in 2015 – all 251,469 pounds of it. To express just how staggeringly small the figure of 10ppb is, if we assume that all of that cannabis was contaminated with 10ppb of abamectin, the total mass of abamectin in that huge amount of cannabis would be just 1.143g – less than half the mass of a penny.
To me, that is an extremely compelling picture. The fact is there are instruments available that can measure such infinitesimal concentrations. What’s more, these tiny concentrations can be measured in the presence of relatively massive amounts of other compounds – cannabinoids, terpenes, sugars, fats – that are always present in any given cannabis sample. The point I’d like to make is that the accurate measurement of trace amounts of cannabis contaminants including pesticides and residual solvents is an astounding feat that borders on magical. This feat is not magic though. It requires extremely delicate instrumentation, ultra-pure reagents, expert analysts, and labor-intensive sample preparation. It is far from trivial, and unlike magic, requires a large investment on the part of the laboratories performing this feat of science. Other industries have embraced this reality, and the cannabis industry is well on its way toward that end…hopefully this article will help put the job of the cannabis analytical lab into perspective.
Using well plates for dSPE sorbents can help expedite sample clean up.
Sample volume remains to be the primary influence on whether an automated solution is a logical investment for a cannabis testing facility. Due to both the complexity of the material being tested and the extraction approach at hand, it may be difficult to find an automated platform that can fully accommodate your laboratory’s needs. Hamilton Robotics in collaboration with United Chemical Technologies (UCT) has developed a solution that allows for automation of specific sample clean up steps commonly utilized in cannabis pesticide testing schemes. The MPE2 Positive Pressure Extraction/Evaporation Module is a standalone manifold that can also be incorporated into a number of automated liquid handling decks. Used in tandem with dispersive solid phase extraction (dSPE) salts/sorbents packed into a 96 well plate, this combination provides laboratories with high throughput extraction convenience with comparable results to traditional dSPE for the analysis of over forty pesticides.
As states continue to expand testing requirements for pesticides, it is vital that your laboratory is equipped with a method that allows versatility for the addition of new compounds without burdening your extraction team. There are a variety of dSPE salt and sorbent blends readily available that have been optimized for cannabis extractions. This allows for the use of a reliable extraction technique that can be adapted for the automation age. Hamilton is widely recognized throughout both clinical and forensic laboratory settings and the MPE2 platform is an excellent first system for laboratories beginning to automate/semi-automate their processes.
Following an initial QuEChERS extraction, additional cleanup is typically recommended for extracts that are being analyzed for pesticide content due to the low detection limits often required. dSPE provides the necessary sample clean up to obtain those thresholds, but often burdens a laboratory staff with additional time consuming preparation steps. Traditionally, dSPE salts are packed into 2 mL centrifugation tubes that require a cumbersome supernatant pipetting step followed by additional vortex, spin and transfer steps. By packing the dSPE sorbents into a well plate format, the user is able to completely automate this above described clean up ultimately saving time and adding convenience without jeopardizing any recovery data.
For most compounds, the recovery was greater than 65% for both methods of dSPE. The mean recoveries for traditional dSPE were 98.0%, 99.2% and 97.9% at pesticide concentrations of 50 ng/mL, 100 ng/mL and 200 ng/mL, respectively. For comparison, the mean recoveries at the same concentrations for well plate dSPE were 85.0%, 88.9% and 89.1%. Therefore, there was typically about a 10-11% absolute difference in recovery between the two methods, which can be corrected for by implementing the use of internal standards. When comparing the recovery differences between the two methods, there are six compounds with noticeably larger discrepancies across all three concentrations, namely: chlorpyrifos, cyprodinil, diazinon, spinetoram, spiromesifen 278 and trifloxystrobin. If these data sets are excluded, then the average absolute differences in recovery between the two methods decrease to 8.8%, 6.4% and 5.8% for concentrations of 50 ng/mL, 100 ng/mL and 200 ng/mL, respectively.
Overall, laboratories can estimate on saving 40-60 minutes per 96 samples processed using the Hamilton MPE2 in conjunction with a UCT dSPE plate. When a liquid handling robot is also available, this time saving estimation is potentially doubled. Time spent per sample, including the training of laboratory scientists, is an important factor to consider when setting up your laboratory. Automation is in an investment that can greatly reduce a laboratory’s overall labor costs in the long run.
This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
We use tracking pixels that set your arrival time at our website, this is used as part of our anti-spam and security measures. Disabling this tracking pixel would disable some of our security measures, and is therefore considered necessary for the safe operation of the website. This tracking pixel is cleared from your system when you delete files in your history.
We also use cookies to store your preferences regarding the setting of 3rd Party Cookies.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
In reality, according to a 
