In a press release sent out this month, bioMérieux announced they have received the very first approvals in cannabis and hemp for AOAC Research Institute Performance Testing Methods (PTM). AOAC approved method validation for the detection of Salmonella and STEC (Shiga toxin-producing E. coli) in cannabis flower utilizing bioMérieux GENE- UP® SLM2 (PTM 121802) and EHEC (PTM 121806) assays.
According to the press release, these validations are the first of their kind in the cannabis and hemp industries. The AOAC-validated testing methods are approved for 1-gram and 10-gram samples.
Dr. Stan Bailey, senior director of scientific affairs at bioMérieux, says these approvals demonstrate the company’s commitment to innovative and validated science in the cannabis and hemp industries. “We are especially proud that the GENE-UP SLM2 and EHEC are the first two AOAC approvals in the United States for cannabis and hemp,” says Dr. Bailey. “This is increasingly important with now over half the population of the US living in states that have approved cannabis for recreational use and most states approving cannabis for medical use.”
The AOAC PTM designations are recognized by the US Department of Agriculture, the Food and Drug Administration, and global regulatory agencies. The validation guidance builds on AOAC’s Cannabis Analytical Science Program (CASP).
bioMérieux is a French in vitro diagnostics company that serves the global testing market. They provide diagnostic solutions such as systems, reagents, software and services.
The Agriculture Improvement Act, also known as the Farm Bill, was signed into law in December 2018. A major provision in the law legalizes hemp as an industrial crop. In August of 2016, USDA, DEA, and FDA published a Statement of Principles in the Federal Register (FR 53365) that defined industrial hemp as any part or derivative (including seeds) of the plant Cannabis sativa L. with a dry weight concentration of tetrahydrocannabinols not greater than 0.3% (wt/wt).
Globally, the hemp market was estimated at $3.9 billion in 2017 and the hemp seed segment is predicted to grow “at a CAGR of 17.1%” through 2025. Some of the markets affected by hemp production include nutraceuticals, food, textiles, construction materials, and personal care products. It is also anticipated that cannabidiol (a non-psychoactive cannabinoid extracted from hemp) production will grow to support the burgeoning recreational and medicinal cannabis markets in the U.S., Canada and other countries around the world.
In U.S. states and Canada where recreational or medicinal marijuana programs have been legalized, regulations have been defined to assure the safety and quality of the products sold to consumers. These regulations include analytical chemistry and biological assays to identify and quantify pesticides, mycotoxins, heavy metals, residual manufacturing solvents, terpenes, and microbial contaminates. With regards to hemp, the USDA recently released guidelines for testing of hemp. To date, the only required test from the Federal perspective is total ∆9-tetrahydrocannabinol (THC) content < 0.3% by weight. Total THC is essentially the sum of tetrahydrocannabinolic acid (THCA) and THC (Total THC = 0.877(THCA) + THC) but this may be eventually expanded to include all salts and isomers of cannabinols as noted above. Another complication: what constitutes “dry”? The CFR does not answer this.
Agilent Technologies has invested in the development and implementation of the analytical protocol, the services needed to support these assays, the required consumables, reagents, and supplies, and the training of sales and support personnel to comprehensively ensure compliance of hemp with USDA regulations.
Vintners have known for centuries that every step in the winemaking process—from cultivation and harvest techniques to fermentation, aging and bottling—has immense impact on the quality and value of the final product.
And that same level of scrutiny is now being applied to cannabis production.
As someone who has worked in the consumer-packaged goods (CPG) space for decades, I’ve been interested in finding out how post-harvest storage and packaging affect the quality and value of cannabis flower. After digging into the issue some more, storage conditions and humidity levels have indeed come into focus as major factors, beyond just the challenges of preventing mold.
I enlisted my research team at Boveda, which has studied moisture control in all manner of manufactured and natural CPG products, to look closer at what’s happening with cannabis once it leaves the cultivation room. There’s not a lot of research on cannabis storage—we checked—and so we explored this aspect further. We were frankly surprised by what a big effect evaporation has on quality and how this is playing out on the retail level.
We suspected moisture loss could affect the bottom line too, and so we did some number-crunching.
It’s well understood that the weight of cannabis flower directly correlates with its profitability—the heavier the yield, the higher the market value. Here’s what our analysis found: A mere 5% dip below the optimal relative humidity (RH) storage environment eliminates six pounds per every 1,000 pounds of cannabis flower. At $5 per gram wholesale, that works out to upwards of $13,500 in lost revenue—and that’s with just a 5% drop in RH below the target range of 55-65% established by ASTM International, an independent industry standards organization.
We also purchased flower at retailers in multiple state markets and commissioned a lab to test the samples, which revealed that most strains sold today are well below the optimal RH range (55-65%). Regardless of fluctuating wholesale prices, when you do the math it’s clear that tens of thousands of dollars in revenue are simply evaporating into thin air.
Why So Dry?
Historically, cultivators, processors and packagers have emphasized keeping flower below a particular humidity “ceiling” for a reason: Flower that’s too moist is prone to hazardous mold and microbial growth, so it’s understandable that many operators err on the side of being overly dry.
The misconception that cannabis flower can be “rehydrated” is another cause of dryness damage. But this method irrevocably damages the quality of the flower through trichome damage.
Those delicate plant structures that house the all-important cannabinoids and terpenes become brittle and fragile when stored in an overly dry environment, and are prone to breaking off from the flower; they cannot not be recovered even if the flower is later rehydrated.
When trichomes are compromised, terpenes responsible for the aroma, taste and scent of cannabis also can evaporate. Overly dried-out cannabis doesn’t just lose weight and efficacy—it loses shelf appeal, which is particularly risky in today’s market.
Cured cannabis flower can remain in storage potentially for months prior to sale or consumption. By the time it reaches the end consumer, much of the cannabis sold in regulated environments in the U.S. and Canada has suffered from dry damage.
There are various humidity controls available for cannabis cultivators: desiccants that absorb water vapor; mechanical equipment that alters RH on a larger scale; or two-way humidity-control packets designed for storage containers.
In the CPG sector, with other moisture-sensitive products such as foods and electronics, we’ve seen that employing humidity controls will preserve quality, and cannabis flower is no different.
Saltwater-based humidity control solutions with two-way vapor-phase osmosis technology automatically add or remove water vapor as needed to maintain a constant, predetermined RH level and ensures a consistent level of moisture weight inside the cannabis flower.
Here’s one more notable finding we discovered in our storage research: Third-party lab tests commissioned by Boveda showed cannabis stored with humidity control had terpene and cannabinoid levels that were 15% higher than cannabis stored without.
Cannabis stored within the optimal humidity range maximizes all the qualities that attract and retain customers. Similar to wine-making, when cannabis cultivators focus on quality control they need to look beyond the harvest.
With legalization rapidly increasing across states, the cannabis market is exploding. And with estimates of sales in the billions, it’s no surprise that greenhouses and grow rooms are emerging everywhere. As growers and extracting facilities continue to expand one important consideration that most tend to underestimate, is how flooring can impact both their production and product. Bare concrete is often a popular choice in cannabis facilities, as there are typically very minimal costs−if any at all−associated with preparing it for use. However, concrete floors can pose unique challenges when left untreated, which could inadvertently create unforeseen problems and unexpected costs.
Understanding the Risks of Bare Concrete Flooring
Whether a facility is growing or extracting, the proper flooring can play a critical role in helping maintain optimal safety and sanitation standards, while simultaneously contributing to production. That’s why its important for growers and extractors to know and understand the potential risks associated with bare concrete.
Concrete is porous: While concrete is a solid material, people may forget that it is porous. Unfortunately, these pores can absorb liquids and harbor small particles that spill on the floor. They create perfect hiding places for bacteria and other pathogens to proliferate. Pathogens can then contaminate product within the facility, causing a halt on production, and/or a potential product recall. This can incur unexpected costs associated with shutdown time and loss of product.
Concrete can be damp: When in a facility with an untreated concrete floor, at times the slab can feel slightly wet or damp to touch. This is due to moisture within the concrete that can eventually work its way up to the surface of the slab. When this happens, items that are placed on top of the floor can be damaged by trapped moisture above the slab and below the object. When this happens, if a product is not protected properly, it can be damaged.
Concrete is dark and unreflective: An untreated concrete slab can often make a room feel dark and it does not reflect lighting within the room. This can result in the need for extra lights and electricity to properly grow cannabis.
Concrete lacks texture: When working in areas where water and other liquids can fall to the ground and accumulate, flooring with traction can play a key role in helping aid against slip and fall incidents. Untreated concrete typically does not provide sufficient texture and can become very slippery when wet.
The Benefits of Bare Concrete Flooring
While the previously mentioned risks can be associated with bare concrete flooring, there is an upside to the situation! Concrete is the perfect substrate for adding a coating that is built to withstand the industry’s demands.
With the application of a fluid-applied or resinous floor coating, the risks of bare concrete flooring can be mitigated. There are a variety of resin and fluid-based coating systems that can be applied, such as:
Epoxy and Urethane Systems
Urethane Mortar Systems
Decorative Quartz Systems
Decorative Flake Systems
These durable coatings have numerous benefits and can offer:
Protection against the proliferation bacteria and other pathogens: Unlike porous concrete, a smooth and virtually seamless floor coating eliminates the little crevices where pathogens can grow. This in turn helps aid against the growth of bacteria, keeping hygiene standards at the forefront and grow rooms in full operations.
Protection against moisture damage: As moisture within the concrete can move upward to the surface of the slab, there are moisture mitigation coating systems, that keep it trapped below the surface, thus helping toprotect items placed on the floor.
Brighter spaces and light reflection: Installing a floor coating that is light in color, such as white or light gray, can help brighten any space. The benefits of this are twofold: First, it can help with visibility, helping employees navigate the space safely. Secondly, light reflectivity of the flooring improves lighting efficiency, resulting in fewer light fixtures and smaller electric costs.
Texture options to help aid against slip and fall incidents: Floor coating systems can offer a variety of texture options−from light grit to heavy grit−depending on how much accumulated water and foot traffic the area receives. Without additional texture in wet areas, slip and fall incidents and injuries are inevitable.
A wide range of colors and decorative systems: These coating systems can be designed to match the aesthetics of the building or corporate colors. Some manufacturers even offer color matching upon request. When it comes to colors, the options are virtually endless.
Choosing the Right Flooring: Considering Bare Concrete
Choosing the right flooring for a cannabis greenhouse or processing facility requires important consideration as every grow room and greenhouse is different. Bare concrete is a popular flooring option for manufacturing and processing facilities across industries, however, as discussed, it can pose unique challenges due to its innate nature. That said, by taking the right steps to ensure that the concrete substrate is properly sealed, it can then be an effective and hygienic flooring option, offering high durability and a longer life cycle.
Microbial contamination on cannabis products represents one of the most significant threats to cannabis consumers, particularly immunocompromised patients who are at risk of developing harmful and potentially fatal infections.
As a result, regulatory bodies in the United States and Canada mandate testing cannabis products for certain microbes. The two most popular methods for microbial safety testing in the cannabis industry are culture-based testing and quantitative polymerase chain reaction (qPCR).
When considering patient safety, labs should choose a method that provides an accurate account of what is living on the sample and can specifically target the most harmful microbes, regardless of the matrix.
1. The Method’s Results Must Accurately Reflect the Microbial Population on the Sample
The main objective of any microbial safety test is to give the operator an indication of the microbial population present on the sample.
Culture-based methods measure contamination by observing how many organisms grow in a given medium. However, not all microbial organisms grow at the same rate. In some cases, certain organisms will out-compete others and as a result, the population in a post-culture environment is radically different than what was on the original sample.
One study analyzed fifteen medicinal cannabis samples using two commercially available culture-based methods. To enumerate and differentiate bacteria and fungi present before and after growth on culture-based media, all samples were further subjected to next-generation sequencing (NGS) and metagenomic analyses (MA). Figure 1 illustrates MA data collected directly from plant material before and after culture on 3M petrifilm and culture-based platforms.
The results demonstrate substantial shifts in bacterial and fungal growth after culturing on the 3M petrifilm and culture-based platforms. Thus, the final composition of microbes after culturing is markedly different from the starting sample. Most concerning is the frequent identification of bacterial species in systems designed for the exclusive quantification of yeast and mold, as quantified by elevated total aerobic count (TAC) Cq values after culture in the total yeast and mold (TYM) medium. The presence of bacterial colonies on TYM growth plates or cartridges may falsely increase the rejection rate of cannabis samples for fungal contamination. These observations call into question the specificity claims of these platforms.
The Live Dead Problem
One of the common objections to using qPCR for microbial safety testing is the fact that the method does not distinguish between live and dead DNA. PCR primers and probes will amplify any DNA in the sample that matches the target sequence, regardless of viability. Critics claim that this can lead to false positives because DNA from non-viable organisms can inflate results. This is often called the Live-Dead problem. However, scientists have developed multiple solutions to this problem. Most recently, Medicinal Genomics developed the Grim Reefer Free DNA Removal Kit, which eliminates free DNA contained in a sample by simply adding an enzyme and buffer and incubating for 10 minutes. The enzyme is instantaneously inactivated when lysis buffer is added, which prevents the Grim Reefer Enzyme from eliminating DNA when the viable cells are lysed (see Figure 2).
2. Method Must Be Able to Detect Specific Harmful Species
Conversely, qPCR assays, such as the PathoSEEK, are designed to target DNA sequences that are unique to pathogenic Aspergillus species, and they can be run using standard qPCR instruments such as the Agilent AriaMx. The primers are so specific that a single DNA base difference in the sequence can determine whether binding occurs. This specificity reduces the frequency of false positives in pathogen detection, a frequent problem with culture-based cannabis testing methods.
Additionally, Medicinal Genomics has developed a multiplex assay that can detect the four pathogenic species of Aspergillus (A. flavus, A. fumigatus, A. niger, and A. terreus) in a single reaction.
3. The Method Must Work on Multiple Matrices
Marijuana infused products (MIPs) are a very diverse class of matrices that behave very differently than cannabis flowers. Gummy bears, chocolates, oils and tinctures all present different challenges to culture-based techniques as the sugars and carbohydrates can radically alter the carbon sources available for growth. To assess the impact of MIPs on colony-forming units per gram of sample (CFU/g) enumeration, The Medicinal Genomics team spiked a known amount of live E. coli into three different environments: tryptic soy broth (TSB), hemp oil and hard candy. The team then homogenized the samples, pipetted amounts from each onto 3M™ Petrifilm E. coli / Coliform Count (EC) Plates, and incubated for 96 hours. The team also placed TSB without any E. coli onto a petrifilm to serve as a control. Figures 3 and 4 show the results in 24-hour intervals.
This implies the MIPs are interfering with the reporter assay on the films or that the MIPs are antiseptic in nature.
Many MIPs use citric acid as a flavoring ingredient which may interfere with 3M reporter chemistry. In contrast, the qPCR signal from the Agilent AriaMx was constant, implying there is microbial contamination present on the films, but the colony formation or reporting is inhibited.
This is not an issue with DNA-based methods, so long as the DNA extraction method has been validated on these matrices. For example, the SenSATIVAx DNA extraction method is efficient in different matrices, DNA was spiked into various MIPs as shown in Table 1, and at different numbers of DNA copies into chocolate (Table 2). The SenSATIVAx DNA extraction kit successfully captures the varying levels of DNA, and the PathoSEEK detection assay can successfully detect that range of DNA. Table 3 demonstrates that SenSATIVAx DNA extraction can successfully lyse the cells of the microbes that may be present on cannabis for a variety of organisms spiked onto cannabis flower samples.
Consumers are largely unaware that most commercial cannabis grown today undergoes some form of decontamination to treat the industry’s growing problem of mold, yeast and other microbial pathogens. As more cannabis brands fail regulatory testing for contaminants, businesses are increasingly turning to radiation, ozone gas, hydrogen peroxide or other damaging remediation methods to ensure compliance and avoid product recalls. It has made cannabis cultivation and extraction more challenging and more expensive than ever, not to mention inflaming the industry’s ongoing supply problem.
The problem is only going to get worse as states like Nevada and California are beginning to implement more regulations including even tougher microbial contamination limits. The technological and economic burdens are becoming too much for some cultivators, driving some of them out of business. It’s also putting an even greater strain on them to meet product demand.
It’s critical that the industry establishes new product standards to reassure consumers that the cannabis products they buy are safe. But it is even more critical that the industry look beyond traditional agricultural remediation methods to solve the microbial problems.
Mold and other microbial pathogens are found everywhere in the environment, including the air, food and water that people consume. While there is no consensus yet on the health consequences of consuming these contaminants through cannabis, risks are certainly emerging. According to a 2015 study by the Cannabis Safety Institutei, molds are generally harmless in the environment, but some may present a health threat when inhaled, particularly to immunocompromised individuals. Mycotoxins resulting from molds such as Aspergillus can cause illnesses such as allergic bronchopulmonary aspergillosis. Even when killed with treatment, the dead pathogens could trigger allergies or asthma.
There is an abundance of pathogens that can affect cannabis cultivation, but the most common types are Botrytis (bud rot, sometimes called gray mold) and Powdery Mildew. They are also among the most devastating blights to cannabis crops. Numerous chemical controls are available to help prevent or stem an outbreak, ranging from fungicides and horticultural oils to bicarbonates and biological controls. While these controls may save an otherwise doomed crop, they introduce their own potential health risks through the overexposure and consumption of chemical residues.
The issue is further compounded by the fact that the states in which cannabis is legal can’t agree on which microbial pathogens to test for, nor how to test. Colorado, for instance, requires only three pathogen tests (for salmonella, E. coli, and mycotoxins from mold), while Massachusetts has exceedingly strict testing regulations for clean products. Massachusetts-based testing lab, ProVerde Laboratories, reports that approximately 30% of the cannabis flowers it tests have some kind of mold or yeast contamination.
If a cannabis product fails required microbial testing and can’t be remedied in a compliant way, the grower will inevitably experience a severe – and potentially crippling – financial hit to a lost crop. Willow Industries, a microbial remediation company, says that cannabis microbial contamination is projected to be a $3 billion problem by 2020ii.
Remediation Falls Short
With the financial stakes so high, the cannabis industry has taken cues from the food industry and adopted a variety of ways to remediate cannabis harvests contaminated with pathogens. Ketch DeGabrielle of Qloris Consulting spent two years studying cannabis microbial remediation methods and summarized their pros and consiii.
He found that some common sterilization approaches like autoclaves, steam and dry heat are impractical for cannabis due the decarboxylation and harsh damage they inflict on the product. Some growers spray or immerse cannabis flowers in hydrogen peroxide, but the resulting moisture can actually cause more spores to germinate, while the chemical reduces the terpene content in the flowers.
The more favored, technologically advanced remediation approaches include ozone or similar gas treatment, which is relatively inexpensive and treats the entire plant. However, it’s difficult to gas products on a large scale, and gas results in terpene loss. Microwaves can kill pathogens effectively through cellular rupture, but can burn the product. Ionizing radiation kills microbial life by destroying their DNA, but the process can create carcinogenic chemical compounds and harmful free radicals. Radio frequency (which DeGabrielle considers the best method) effectively kills yeast and mold by oscillating the water in them, but it can result in moisture and terpene loss.
The bottom line: no remediation method is perfect. Prevention of microbial contamination is a better approach. But all three conventional approaches to cannabis cultivation – outdoors, greenhouses and indoor grow operations – make it extremely difficult to control contamination. Mold spores can easily gain a foothold both indoors and out through air, water, food and human contact, quickly spreading into an epidemic.
The industry needs to establish new quality standards for product purity and employ new growing practices to meet them. Advanced technologies can help create near perfect growing ecosystems and microclimates for growing cannabis free of mold contamination. Internet of Things sensors combined with AI-driven robotics and automation can dramatically reduce human intervention in the growing process, along with human-induced contamination. Natural sunlight supplemented with new lighting technologies that provide near full-light and UV spectrum can stimulate robust growth more resistant to disease. Computational fluid dynamic models can help growers achieve optimal temperature, humidity, velocity, filtration and sanitation of air flow. And tissue culture micropropagation of plant stock can eliminate virus and pathogen threats, to name just a few of the latest innovations.
Growing legal cannabis today is a risky business that can cost growers millions of dollars if pathogens contaminate a crop. Remediation methods to remove microbial contamination may work to varying degrees, but they introduce another set of problems that can impact consumer health and comprise product quality.
Someone approached me the other day, wanting to know what was the real story about hemp and CBD.
He said he had “a guy” who gave him a CBD salve as part of a study, supposedly “the good stuff,” to help his knee. He couldn’t understand why he was the only one out of 20 people in the group that felt no relief. He happened to have this CBD salve with him, along with a second brand that he hadn’t yet tried. The “good stuff” had slick, colorful packaging, a beautiful logo and powerful marketing messages about the phytocannabinoids and essential oils in the jar. The other CBD product was in a dull grey tin, an ugly duckling, and not nearly so impressive on the outside- I’ll call it “Homer’s Brew.” My friend dismissed Homer’s Brew outright, as not even worth trying. I told him that not all CBD products are created equal, that you can’t always believe the claims on the package, including the cannabinoid potency displayed on the label.
I told him to search for the Certificate of Analysis (COA) for each of the two products, specifically, lab test results validating the CBD dosage per serving, and also the breakdown of pesticides, heavy metals and microbials. He had to do a little digging and emailing, as it wasn’t readily available for either company, but the next day, results were in. The “good stuff” with the slick packaging and bold claims had mere trace amounts of CBD, with some hemp and essential oils- no tests for pesticides or contaminants of any kind. Hmmm, no wonder he was disappointed. Homer’s Brew’s COA came in with flying colors – a reputable lab had confirmed safe levels of pesticides, pathogens and heavy metals, and the CBD level was substantial, with a detailed cannabinoid breakdown in the lab report.
In spite of the varying legality of hemp-derived CBD products from one state to the next, consumers are gobbling up costly CBD salves, tinctures and edibles in markets, gyms and online. Like moths to a flame, they are pulled in by the CBD name and lofty promises, not always understanding what they are getting for their money. They trust that these products are safe, licensed, inspected and regulated by some agency, otherwise, “they wouldn’t be on the shelves, would they?”
In spite of the 2018 Farm Bill, FDA still has not recognized the legality of products containing hemp-derived CBD, but some states have gone ahead and given them a green light anyway- check with your own jurisdiction to be sure. In the meantime, hemp-derived CBD products are slipping through the regulatory cracks, depending on the state. It is confusing, for sure, and buyer beware.
Separate yourself from the pack of snake-oil salesmen. Test your products for safety and accurate cannabinoid potency, and make a Certificate of Analysis readily available to your customers. Boldly portray your transparency and belief in the quality of your products through this COA.
Providing this information to consumers is the best path to success- safe, satisfied customers who will refer to their friends and family, and most likely come back for more of your “good stuff.”
Encore Labs is a full-service cannabis testing lab in Pasadena, California, providing all testing needs required by California’s Bureau of Cannabis Control (BCC). The BCC requires that cannabis products being sold in licensed dispensaries be tested for cannabinoid potency, heavy metals, microbial impurities, moisture content and water activity, mycotoxins, residual pesticides, residual solvents and processing chemicals, foreign materials and terpenes. It is Encore Labs’ goal to guarantee the quality and potency of all cannabis products while ensuring regulatory guidelines are met in the state of California.
Encore Labs provides quick turnaround times on a consistent basis. They take pride in offering excellent customer service without diminishing the quality of the work that they do. Their team of laboratory analysts/technicians are passionate about the industry and will never compromise their integrity just to make an extra buck.
Co-Founder, Spencer Wong, mentions their personal connection with clients. “Our customers don’t just see us as their testing laboratory, they see Encore Labs as their laboratory partner,” says Wong. “Besides performing analytical testing, we have worked with many customers to help formulate new products and do root cause analysis to pinpoint inefficiencies in their manufacturing operations and cultivation farms.”
ISO/IEC 17025 Accreditation has been extremely valuable to Encore Labs, especially regarding the new cannabis testing industry. “Our experience with Perry Johnson Laboratory Accreditation, Inc. has been great and has allowed for a very smooth and straightforward initial accreditation process. Their staff has been knowledgeable and responsive every step of the way,” says Wong.
Accreditation establishes that steps are being taken regarding quality and that laboratories are meeting and exceeding the highest testing standards. It also provides further assurance and confidence in data results as well as validated methods, staff training procedures, equipment calibration and successful participation in proficiency testing/interlaboratory comparisons.
Starting out with 1500 square feet of laboratory space, within the last year Encore Labs has doubled its work area. In order to meet the growing demand of the cannabis testing industry, they have added plans to once again double in size by the end of 2019, as well as open a second laboratory by the end of 2020.
The cannabis industry is growing exponentially, and the use of cannabis for medical purposes is being adopted across the nation. With this boom in cannabis consumers, there has been an increasing need for knowledge about the product.
The role of testing labs has become crucial to the process, which makes owning and operating a lab more lucrative. Scientists testing for potency, heavy metals, pesticides, residual solvents, moisture, terpene profile, microbial and fungal growth, and mycotoxins/aflatoxins are able to make meaningful contributions to the medical industry by making sure products are safe, while simultaneously generating profits and a return on investment.
Here are the key testing instruments you need to conduct these critical analyses. Note that cannabis analytical testing requirements may vary by state, so be sure to check the regulations applicable to the location of your laboratory.
The most important component of cannabis testing is the analysis of cannabinoid profiles, also known as potency. Cannabis plants naturally produce cannabinoids that determine the overall effect and strength of the cultivar, which is also referred to as the strain. There are many different cannabinoids that all have distinct medicinal effects. However, most states only require testing and reporting for the dry weight percentages of delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). It should be noted that delta-9-tetrahydrocannabinolic acid (Δ9-THCA) can be converted to THC through oxidation with heat or light.
For potency testing, traditional high-performance liquid chromatography (HPLC) is recommended and has become the gold standard for analyzing cannabinoid profiles. Look for a turnkey HPLC analyzer that delivers a comprehensive package that integrates instrument hardware, software, consumables and proven HPLC methods.
Heavy Metal Testing
Different types of metals can be found in soils and fertilizers, and as cannabis plants grow, they tend to draw in these metals from the soil. Heavy metals are a group of metals considered to be toxic, and the most common include lead, cadmium, arsenic and mercury. Most labs are required to test and confirm that samples are under the allowable toxic concentration limits for these four hazardous metals.
Heavy metal testing is performed by inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS uses the different masses of each element to determine which elements are present within a sample and at what concentrations. Make sure to include accompanying software that provides assistant functions to simplify analysis by developing analytical methods and automatically diagnosing spectral interference. This will provide easy operation and analytical results with exceptionally high reliability.
To reduce running costs, look for a supporting hardware system that reduces the consumption of argon gas and electricity. For example, use a plasma ignition sequence that is optimized for lower-purity argon gas (i.e., 99.9% argon as opposed to more expensive 99.9999%).
The detection of pesticides in cannabis can be a challenge. There are many pesticides that are used in commercial cannabis grow operations to kill the pests that thrive on the plants and in greenhouses. These chemicals are toxic to humans, so confirming their absence from cannabis products is crucial. The number of pesticides that must be tested for varies from state to state, with Colorado requiring only 13 pesticides, whereas Oregon and California require 59 and 66 respectively. Canada has taken it a step further and must test for 96 pesticides, while AOAC International is developing methods for testing for 104 pesticides. The list of pesticides will continue to evolve as the industry evolves.
Testing for pesticides is one of the more problematic analyses, possibly resulting in the need for two different instruments depending on the state’s requirements. For a majority of pesticides, liquid chromatography mass spectrometry (LCMS) is acceptable and operates much like HPLC but utilizes a different detector and sample preparation.
Pesticides that do not ionize well in an LCMS source require the use of a gas chromatography mass spectrometry (GCMS) instrument. The principles of HPLC still apply – you inject a sample, separate it on a column and detect with a detector. However, in this case, a gas (typically helium) is used to carry the sample.
Look for a LC-MS/MS system or HPLC system with a triple quadrupole mass spectrometer that provides ultra-low detection limits, high sensitivity and efficient throughput. Advanced systems can analyze more than 200 pesticides in 12 minutes.
For GCMS analysis, consider an instrument that utilizes a triple quadrupole mass spectrometer to help maximize the capabilities of your laboratory. Select an instrument that is designed with enhanced functionality, analysis software, databases and a sample introduction system. Also include a headspace autosampler, which can also be used for terpene profiles and residual solvent testing.
Residual Solvent Testing
Residual solvents are chemicals left over from the process of extracting cannabinoids and terpenes from the cannabis plant. Common solvents for such extractions include ethanol, butane, propane and hexane. These solvents are evaporated to prepare high-concentration oils and waxes. However, it is sometimes necessary to use large quantities of solvent in order to increase extraction efficiency and to achieve higher levels of purity. Since these solvents are not safe for human consumption, most states require labs to verify that all traces of the substances have been removed.
Testing for residual solvents requires gas chromatography (GC). For this process, a small amount of extract is put into a vial and heated to mimic the natural evaporation process. The amount of solvent that is evaporated from the sample and into the air is referred to as the “headspace.” The headspace is then extracted with a syringe and placed in the injection port of the GC. This technique is called full-evaporated technique (FET) and utilizes the headspace autosampler for the GC.
Look for a GCMS instrument with a headspace autosampler, which can also be used for pesticide and terpene analysis.
Terpene Profile Testing
Terpenes are produced in the trichomes of the cannabis leaves, where THC is created, and are common constituents of the plant’s distinctive flavor and aroma. Terpenes also act as essential medicinal hydrocarbon building blocks, influencing the overall homeopathic and therapeutic effect of the product. The characterization of terpenes and their synergistic effect with cannabinoids are key for identifying the correct cannabis treatment plan for patients with pain, anxiety, epilepsy, depression, cancer and other illnesses. This test is not required by most states, but it is recommended.
The instrumentation that is used for analyzing terpene profiles is a GCMS with headspace autosampler with an appropriate spectral library. Since residual solvent testing is an analysis required by most states, all of the instrumentation required for terpene profiling will already be in your lab.
As with residual solvent testing, look for a GCMS instrument with a headspace autosampler (see above).
Microbe, Fungus and Mycotoxin Testing
Most states mandate that cannabis testing labs analyze samples for any fungal or microbial growth resulting from production or handling, as well as for mycotoxins, which are toxins produced by fungi. With the potential to become lethal, continuous exposure to mycotoxins can lead to a buildup of progressively worse allergic reactions.
LCMS should be used to qualify and identify strains of mycotoxins. However, determining the amount of microorganisms present is another challenge. That testing can be done using enzyme linked immunosorbent assay (ELISA), quantitative polymerase chain reaction (qPCR) or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), with each having their advantages and disadvantages.
For mycotoxin analysis, select a high-sensitivity LC-MS/MS instrument. In addition to standard LC, using an MS/MS selective detector enables labs to obtain limits of detection up to 1000 times greater than conventional LC-UV instruments.
For qPCR and its associated needs, look for a real-time PCR amplification system that combines thermal cyclers with optical reaction modules for singleplex and multiplex detection of fluorophores. These real-time PCR detection systems range from economical two-target detection to sophisticated five-target or more detection systems. The real-time detection platform should offer reliable gradient-enabled thermal cyclers for rapid assay optimization. Accompanying software built to work with the system simplifies plate setup, data collection, data analysis and data visualization of real-time PCR results.
Moisture Content and Water Activity Testing
Moisture content testing is required in some states. Moisture can be extremely detrimental to the quality of stored cannabis products. Dried cannabis typically has a moisture content of 5% to 12%. A moisture content above 12% in dried cannabis is prone to fungal growth (mold). As medical users may be immune deficient and vulnerable to the effects of mold, constant monitoring of moisture is needed. Below a 5% moisture content, the cannabis will turn to a dust-like texture.
The best way to analyze the moisture content of any product is using the thermogravimetric method with a moisture balance instrument. This process involves placing the sample of cannabis into the sample chamber and taking an initial reading. Then the moisture balance instrument heats up until all the moisture has been evaporated out of the sample. A final reading is then taken to determine the percent weight of moisture that was contained in the original sample.
Look for a moisture balance that offers intuitive operation and quick, accurate determination of moisture content. The pan should be spacious enough to allow large samples to be spread thinly. The halogen heater and reflector plate should combine to enable precise, uniform heating. Advanced features can include preset, modifiable measurement modes like automated ending, timed ending, rapid drying, slow drying and step drying.
Another method for preventing mold is monitoring water activity (aW). Very simply, moisture content is the total amount of water available, while water activity is the “free water” that could produce mold. Water activityranges from 0 to 1. Pure water would have an aW of 1.0. ASTM methods D8196-18 and D8297-18 are methods for monitoring water activity in dry cannabis flower. The aW range recommended for storage is 0.55 to 0.65. Some states recommend moisture content to be monitored, other states monitor water activity, and some states such as California recommend monitoring both.
As you can see, cannabis growers benefit tremendously from cannabis testing. Whether meeting state requirements or certifying a product, laboratory testing reduces growers’ risk and ensures delivery of a quality product. As medicinal and recreational cannabis markets continue to grow, analytical testing will ensure that consumers are receiving accurately
labeled products that are free from contamination. That’s why it is important to invest in the future of your cannabis testing lab by selecting the right analytical equipment at the start of your venture.
Earlier this month, Colorado cannabis producer Herbal Wellness LLC recalled dozens of batches of cannabis due to positive yeast and mold tests. The Colorado Department of Public Health and Environment (CDPHE) issued a health and safety advisory following the news of microbial contamination.
The Colorado Department of Revenue then identified batches of both medical and recreational cannabis produced by Herbal Wellness that were not even tested for microbial contaminants, which is a requirement for licensed producers in the state. Just a few days later, the Denver Department of Public Health & Environment (DDPHE) issued a bulletin announcing their plans to conduct random tests at dozens of dispensaries.
“In the coming weeks, the Denver Department of Public Health & Environment (DDPHE) will be conducting an assessment in approximately 25 retail marijuana stores to evaluate contaminants in products on store shelves,” reads the bulletin. “DDPHE has worked with epidemiological partners at Denver Public Heath to create the assessment methodology. Participating stores will be randomly identified for inclusion in the assessment.”
“Current METRC inventory lists for each store will be used to randomly identify samples of flower, trim/shake, and pre-rolls. Each sample will be tested for pesticides and total yeast and mold by a state- and ISO-certified marijuana testing facility. Results of their respective testing will be shared with each facility and will also be shared broadly within a write-up of results.”
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