Tag Archives: Pesticide

By Dr. Markus Roggen

Demand for cannabis extracts, in particular vaping products, is at an all-time high. People want good oil, and they want to know something about the quality of it. It is therefore time to take a step back and consider the process from plant to cartridge. What is the current industry standard for cannabis extraction, what constitutes quality and where might we need to make some adjustments?

Right now, “clear” oil is hot. Customers have been led to believe that a pale gold extract is synonymous with the best possible cannabis concentrate, which is not necessarily the case. Producing a 95% pure THC extract with a translucent appearance is neither a great scientific feat nor a good representation of the whole cannabis flower. Moreover, it runs counter to the current trend of all-natural, non-processed foods and wellness products.

“My carrots are organic and fresh from the farmers market, my drink has no artificial sweeteners and my honey is raw, but my cannabis oil has undergone a dozen steps to look clear and still contains butane.”Cannabis is a fascinating plant. It is the basis of our livelihood, but more importantly, it enhances the quality of life for patients. The cannabis plant offers a plethora of medicinally interesting compounds. THC, CBD and terpenes are the most popular, but there are so many more. As of the most recent count, there are 146 known cannabinoids¹. Cannabinoids are a group of structurally similar molecules², including THC and CBD, many of which have shown biological activity³.

Then there are terpenes. These are the smaller molecules that give cannabis its distinct smell and flavor, over 200 of which have been identified in cannabis⁴. But wait, there’s more. The cannabis plant also produces countless other metabolites: flavonoids, alkaloids, phenols and amides⁵. All these components mixed together give the often-cited entourage effect^6,7.

Current industry standards for cannabis oil extraction and purification stand in marked contrast to the complexity of the plant’s components. Due to an unsophisticated understanding of the extraction process and its underlying chemistry, cannabis oil manufacturers frequently produce oil of low quality with high levels of contamination. This necessitates further purifications and clean up steps that remove such contaminants unfortunately along with beneficial minor plant compounds. If one purifies an extract to a clear THC oil, one cannot also offer the full spectrum of cannabinoids, terpenes and other components. Additionally, claiming purities around 95% THC and being proud of it, makes any self-respecting organic chemist cringe⁸.

Precise control of extraction conditions leads to variable, customized concentrates. THC-A crumble, terpene-rich vape oil, THC sap (from left to right).

The labor-intensive, multi-step extraction process is also contrary to “the clean-label food trend”, which “has gone fully mainstream”⁹. Exposing the cannabis flower and oil to at least half a dozen processing steps violates consumer’s desire for clean medicine. Furthermore, the current practice of calling supercritical-CO₂-extracted oils solvent-less violates basic scientific principles. Firstly, CO₂ is used as a solvent, and secondly, if ethanol is used to winterize¹⁰, this would introduce another solvent to the cannabis oil.

We should reconsider our current extraction practices. We can offer cannabis extracts that are free of harmful solvents and pesticides, give a better, if not full, representation of the cannabis plant and meet the patients’ desire for clean medicine. Realizing extracts as the growth-driver they are¹¹ will make us use better, fresher starting materials¹². Understanding the underlying science and learning about the extraction processes will allow us to fine-tune the process to the point that we target extract customized cannabis concentrates¹³. Those, in turn, will not require additional multi-step purification processes, that destroys the basis of the entourage effect.

The cannabis industry needs to invest and educate. Better extracts are the result of knowledgeable, skilled people using precise instruments. Backroom extraction with a PVC pipe and a lighter should be horror stories of the past. And only when the patient knows how their medicine is made can they make educated choices. Through knowledge, patients will understand why quality has its price.

In short, over-processing to make clear oil violates both the plant’s complexity and consumers’ desires. Let us strive for pure extracts, not clear. Our patients deserve it.

[1] Prof. Meiri; lecture at MedCann 2017

[2] ElSohly, Slade, Life Sciences 2005, 539

[3] Whiting, et. al., JAMA. 2015, 2456

[4] Andre, Hausman, Guerriero, Frontiers in Plant Science 2016, 19

[5] Hazekamp, et. al., Chemistry of Cannabis Chapter 3.24; 2010 Elsevier Ltd.

[6] Ben-Shabat, et al.; Eur J Pharmacol. 1998, 23

[7] Mechoulam, et al.; Nat Prod Rep. 1999, 131

[8] Medical and Research Grade chemicals are generally of purities exceeding 99.9%

[9] Bomgardner, Chemical & Engineering News 2017, 20

[10] Winterization is the industry term for what is correctly referred to as precipitation.

[11] Year-over changes to market shares in Colorado 2015 to 2016: Concentrates 15% to 23%; Flower 65% to 57%, BDS Analytics, Marijuana Market Executive Report, 2017

[12] Further reading about the whole extraction process: B. Grauerholz, M. Roggen; Terpene and Testing Magazine, July/Aug. 2017

[13] Further reading about optimizing CO₂ extraction: M. Roggen; Terpene and Testing Magazine, May/June 2017, 35

July 27, 2017

Soapbox

Cannabis Industry Needs Leadership, Not Pesticides

By Ben Ward

5 Comments

The medical cannabis sector is currently attracting increased attention, as patients, doctors, regulators and investors take a closer look at our industry. There is a lot for them to learn and to benefit from as our industry matures under the glare of the proverbial spotlight. And there’s a lot for those of us in the industry to be proud of. We’re helping patients manage pain, for example. We’re helping them get their lives back.

But that same spotlight is also revealing some problems in our industry.

Take ingredients for example. When I look at the ingredient list in my natural medicines, I don’t expect to see Myclobutanil, Piperonyl Butoxide, Pyrethrin, Bifenezate, and Avermectin listed. Yet, that’s exactly what some licensed producers of cannabis in Canada and some cultivators in California have been selling to their patients. You have to ask yourself why, when pesticides are the only toxic substances released intentionally into our environment to kill living things. Patients don’t take cannabis to harm themselves. They do it to improve their quality of life.

Yet some cannabis companies have violated their patients’ trust in supplying them with something that could harm them. Indeed, recalls for cannabis, unfortunately, are now becoming somewhat commonplace on both sides of the border. These licensed producers – audited and approved by government – are entrusted to produce safe, reliable, consistent medicine for patients. They are entrusted to put safety at the core of their business at all times. But that is clearly not the case in certain circumstances.

In the past year, a few of the 52 licensed producers in Canada have been found to have pesticide contamination in their cannabis products. From what I can see, the explanations given for the presence of these pesticides don’t make sense. Pyrethrin, for instance, has been found on some medical cannabis products shipped out of certain growing facilities. However, pyrethrin does not naturally appear on plants. It has to be intentionally applied, accidentally or otherwise.

That means, in cases where this pesticide has been found on products after they left the growing facility, two things had to have happened. First, someone introduced it onto the plants to deal with an insect infestation. And second, lax quality control standards – perhaps influenced by a short-term focus on profits over patients – allowed infected products to enter their supply chain and, in many cases, to be consumed by patients.

When revealed, those responsible for companies using pesticides such as pyrethrin say they are “shocked”, publicly declaring that they have no clue as to how these toxic substances entered their cultivation processes. The fact is, if you don’t test your inputs, if you fail to test your outputs, and if you manage your business for short-term profits, you shouldn’t be producing cannabis.

There’s no place in healthcare for people who disregard a patient’s well being, because – from a patient’s perspective – what you don’t know could hurt you. No one who grows something can absolutely guarantee that a mistake will never be made, granted. But as the cannabis sector expands, experienced cannabis firms know there’s a direct correlation between attention and leadership: as the world pays more attention to our sector, the onus on us to be stewards in and for our industry also rises.

That means putting patient safety at the centre of everything we do. And that means ensuring patients are consuming safe cannabis produced by licensed companies that are committed to the long-term health and prospects of our growing industry.

July 13, 2017

DigiPath Gets Rec Testing License, Renews Medical License In Nevada

By Aaron G. Biros

1 Comment

According to a press release, Digipath, Inc. (OTCQB: DIGP) was awarded a recreational cannabis-testing license and a renewal of their medical cannabis-testing license in Nevada.

The news came the week following Nevada’s opening day for recreational cannabis sales, which began July 1^st. Some estimates report up to $5 million in sales within the first weekend.

Todd Denkin, founder and president of Digipath

According to Todd Denkin, president of Digipath, that massive start hasn’t showed any signs of slowing. “I was in a dispensary yesterday and it was packed,” says Denkin. “There were 40 people in line and it was pouring rain outside.” He says the flow of customers to dispensaries hasn’t stopped since July 1^st.

Because of that demand as well as the state’s testing requirements, Denkin is preparing to expand. “From a laboratory’s perspective, we expect a large increase in volume,” says Denkin. “Most of the medical cultivators we work with got their rec license as well so we’re working with a lot of the same clients and getting new clients on a regular basis.” Before the launch of recreational sales, DigiPath has been doing lab testing for medical cannabis for over two years.

Cindy Orser, PhD., chief science officer at Digipath, says they are on their way to receiving ISO 17025 accreditation via the American Association for Laboratory Accreditation (A2LA). According to Orser, labs in Nevada must go out and do the sampling themselves, then bring the samples back to the lab for testing. The testing regulations overall seem relatively similar to what we’ve seen develop in other states with required pesticide testing and microbial screening. “We have a list of 24 pesticides, (two of them are plant growth regulators) that we monitor for,” says Orser. “We have specific allowable limits for that set of chemicals.” For microbial testing, Orser says they enumerate total aerobic count (TAC), total yeast and mold (TYM), pathogenic E. coli and Salmonella spp., enterobacteriaceae and bile-tolerant gram-negative, a subset of enterobacteria, as well as screening for mycotoxins. All of the testing in the state goes through just eleven laboratories, including DigiPath.

In preparing for expansion, they are looking at California in addition to other states. California released a set of draft regulations for lab testing in the spring, which many say is an example of regulatory overreach. “We still don’t know exactly what’s going to happen in California,” says Orser. “The draft regulations that have come out are so restrictive.” As Digipath looks toward expanding more in Nevada, California and other states, all eyes are on regulators proposing requirements for laboratory testing. “The future looks promising,” says Denkin.

June 1, 2017

What Does it Really Mean To Be Organic in Cannabis?

By Dr. Allison Justice

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If you ask an organic chemist, it’s any molecule with a carbon attached. If you ask a consumer of USDA Certified Organic vegetables, they might say it is food produced without chemicals pesticides, that it is safer and cleaner and even more nutritious. Possibly another consumer will say it’s just a hoax to pay more for food, but what does the USDA Certified Organic Farmer say?

Most will agree it is a very rigorous process of record keeping, fees, rules and oversight. The farmers have limited choices for pesticides and fertilizers; they incur higher labor costs, suffer potentially lower yields and generally have higher input costs. However, at the end of the day the farmer does get a higher price point.

With so many misconceptions about organic food, it is difficult to know what is actually organic by definition. First let’s think about what the word pesticide means. A pesticide is “a substance used for destroying insects or other organisms harmful to cultivated plants or to animals.” By definition, a vacuum used to suck off spidermites is a pesticide, so instead we should say that no synthetic pesticides are used. These are pesticides that enter and reside for long periods of time within the plant, which are potentially harmful to the end consumer. Though organic food does not contain synthetic pesticides, the perception of the food being healthier is also not always accurate. Growers often use foliar applied teas or manures, which increase the chance of the product containing E. coli or other harmful microbes. In addition, certain sanitizing agents or gamma irradiation is not allowed, so the post-harvest cleaning is not always as thorough as for conventional foods. When cannabis is sold as a dried product, the consumer cannot wash the flower as they might do before eating an apple. As growers, we should make sure we are disinfecting the flower before harvest and keeping the plant/processes clean throughout curing.

I often hear cannabis growers saying they are producing an organic product, but this simply cannot be true. The term “organic” is a labeling term for agricultural products (food, fiber or feed) that have been produced in accordance to the federal government’s USDA organic regulations. Due to our (cannabis growers) ongoing disagreements with the federal government, this is not a term we can put on our product. However, we can still grow to the same standards as USDA-certified farmers. How can we do this? By using OMRI (Organic Materials Review Institute) approved products. OMRI is a third-party, nonprofit organization that lets growers know if a product can be used in certified Organic production. You can find this seal on many fertilizers or pesticides.

Next, if it is a pesticide product that is not OMRI approved, check to see if it is registered by the EPA (Environmental Protection Agency). The EPA will provide ingredients and crops that are approved, amounts which can be used safely and storage/disposal practices on the label. Products that are put through the EPA registration are evaluated for their environmental, human and residual risks. Companies pay a hefty fee for this process, and much research goes into providing this information – ALWAYS READ THE LABEL!

A couple of exceptions to an EPA registration are pesticides that are 25B-exempt and biological control. 25B-exempt pesticides are pesticides that pose minimal or no risk to humans. A complete list of these products can be found here. Examples of these pesticides include rosemary, garlic, spearmint, etc.

Biological control is a method for controlling pests by the use of natural enemies. Biological control agents are allowed in organic production. If you are still wondering which pesticides or fertilizer are OK to use in cannabis and you do not live in a state with already enforced regulation, check out allowed lists in states that do.

So we know we cannot be considered a USDA organic cannabis farmer, but we CAN strive to meet the same standards:

Follow your state’s regulations; they are there for a reason!
Use OMRI products, 25B-exempt products and BCAs.
Keep an eye out for upcoming third-party certification companies, such as Clean Green or MPS (beware of the ones that want you to only use their products), because we need more than the state to regulate what we put onto our crop.
Finally, always think about the microbial load you’ve put on your plants. Although many can be very beneficial and help to produce high quality crops, many species can be harmful to the end user.

May 18, 2017

Regulatory Overreach: Are California’s Lab Rules Too Strict?

By Aaron G. Biros

4 Comments

With California moving into a more regulated market, some are concerned the state may be overregulating the market with strict, unnecessary rules. The Bureau of Marijuana Control, California’s agency in charge of regulatory oversight for the cannabis industry, released a set of proposed draft regulations for lab testing recently.

Jeffrey Raber, Ph.D, Chief Executive Officer of The Werc Shop

Those rules cover everything from sampling standard operating procedures to detection limits for pesticide analytes, which some say are absurdly strict as is. According to Jeffrey Raber, Ph.D, chief executive officer of The Werc Shop, a cannabis consulting firm located in Monrovia, CA, these rules will immediately raise prices. “The regulations are quite extensive and will undoubtedly drive the costs of patient medicine upward,” says Raber. “Regulations are not intended to be so detailed in these fashions, but are supposed to provide the floor and specific framework upon which operators can build best practices and differentiate themselves from others in a competitive market that drives prices downward.”

“Comparable guidance from other states operating today, and even federal regulations, are not nearly as specific in certain aspects,” says Raber. “While there are some very good parts to the current draft, and the bureau has certainly aimed to provide strong consumer protections, as they should, the idea of benzene even being mentioned or possibly permitted, or a completely cold transportation chain being required, and pesticide levels so low it pushes the limits of the most sophisticated and modern analytical equipment while going far past sensible EPA limits, strongly suggests there is work to be done to dial back the current position and make for far more workable and fully balanced regulations before they are fully finalized.”

It is important to note that nothing is set in stone yet. The bureau will hold four public hearings throughout the month of June for the lab testing rules. In addition to that, concerned stakeholders can send written comments through June 20^th.

Dave Egerton, vice president of technical operations at CW Analytical, a cannabis-testing lab based in Oakland, is pleased they are finally regulating the market, but definitely plans on providing some feedback to change the rules a bit. “CW Analytical applauds the state’s efforts to regulate laboratories and the cannabis industry in general,” says Egerton. “…Many aspects of the proposed regulations for labs will make for a marked shift in the way our businesses operate, but the motivation behind them is well-intended.” His sentiment is consistent with many who operate cannabis laboratories and other stakeholders who see these proposed rules as overreach.

“Unfortunately, some of the regulations as written will create undo burden upon the industry and carry a strong probability of limiting supply to medical patients,” says Egerton. “During the current review period, CA laboratories will be providing feedback on some of the details within the law in order to streamline their quality assurance goals into a more tenable document that still protects patients.” That public comment period is a crucial part of the rulemaking process, as the rules will most likely change after cannabis laboratories’ voices are heard.

April 26, 2017

Colorado Issues Safety Advisory Over Pesticide Contamination Concerns

By Aaron G. Biros

3 Comments

The Colorado Department of Revenue (DOR), in conjunction with the Colorado Department of Agriculture (CDA) and the Colorado Department of Public Health and Environment (CDPHE) issued two public health and safety advisories this morning after they identified pesticide residues on dried cannabis flower, trim, concentrates and infused products, according to the advisory. The contaminated products come from cannabis grown by Rocky Mountain Ways, LLC and Herbal Options, LLC, both doing business as Good Meds.

The Advisory was issued at 10am MT this morning

The advisory cautions consumers to check their labels for the license numbers of the businesses and the harvest batch numbers. They list the license number as, “Medical Optional Premises Cultivation License 403-001116 and/or Medical Marijuana Center License 402-00736.” The harvest batch numbers in question are B11H15.041317-Headband, B11H15.041317-Night Terror OG, and B11H15.041217-Citrix.

The CDA found the presence of off-label pesticides, including Pyrimethanil, Tebuconazole, and Spinosyn, in the products. Pyrimethanil is a fungicide commonly used on seeds, but it is generally regarded as not acutely toxic to humans. Tebuconazole is another fungicide, while the FDA says it is safe for humans, other sources say it could have a moderate acute toxicity in humans. Spinosyn is a class of insecticides with a slight acute toxicity to humans and has been the culprit in a previous cannabis recall in Oregon. In the public health and safety advisory, the CDPHE and DOR say the pesticides were used off-label and none of them are on the approved list of pesticides for cannabis.

The license numbers and batch harvest numbers in question

April 19, 2017

Judging a Craft Cannabis Competition

By Aaron G. Biros

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Willamette Week, a Portland-based publication, is hosting the 2017 Cultivation Classic with Farma, Cascadia Labs, Phylos Bioscience and the Resource Innovation Institute on May 12^th. The event is a benefit for the Ethical Cannabis Alliance, an organization that promotes sustainability, labor standards and education surrounding the integrity and ethics of growing cannabis. Cultivation Classic is a competition for pesticide-free cannabis grown in Oregon, according to a press release.

Congressman Earl Blumenauer speaking at last year’s Cultivation Classic
Photo: Bridget Baker, 92bridges.com

While the event’s focus is on the competition, it is just as much a celebration of the craft cannabis community in Oregon. This year’s competition incorporates scientific collaboration like genetic sequencing for the winners by Phylos Bioscience and carbon accounting for all competitors. Keynote speakers include Ethan Russo, medical director of PHYTECS and Dr. Adie Po, co-founder of Habu Health. Congressman Earl Blumenauer, a prominent cannabis legalization advocate in Oregon, will also be speaking at the awards ceremony. You can check out the full schedule and speaker lineup here.

Raymond Bowser, breeder at Home Grown Natural Wonders, is a judge for this year’s Cultivation Classic. He speaks at cannabis conferences around the country and his business created a number of different strains, so he has experience with a myriad of growers and strains. “This time around everyone has really stepped up their game,” says Bowser. “The entries are noticeably better than last year.” When looking at the different samples sent to him, he sees a few key factors as most important in judging the quality. “What I am looking for is simple; a nice smell and a decent look, generally speaking,” says Bowser. “Aesthetics can tell you a lot about how it was grown, temperature changes and the overall care taken in cultivating and curing the flower.” For him, flavor, smell and aesthetics are the big variables to consider.

Those are factors that his company holds to high standards in their work, so he judges the samples based on the same variables. “It is what we strive for in our gardens and so far the samples I have tried are fantastic in that regard,” says Bowser. In other competitions that Bowser has judged in the past, they sent him between 40 and 60 strains to judge in seven days. “That is not conducive to a fair evaluation,” says Bowser. “Here, we are getting fourteen or so different strains, so we can sample one strain a day which is how I personally like to do it.”

Bowser is supportive of Cultivation Classic because of their emphasis on the craft industry. “We talk about craft cannabis and breeding craft cultivars at conferences around the country,” says Bowser. “With the rec industry growing so much, we see so many people cutting corners to save money, that it is refreshing to see growers take pride in the craft.” He also stresses the need for good lab testing and sound science in the trade. “I am big on lab testing; it is very important to get all the right analytics when creating strains,” says Bowser. “Cascadia is a solid choice for the competition; they have been a very good, consistent lab.” Emphasizing the local, sustainability-oriented culture surrounding the craft market, Bowser is pleased that this competition supports that same message. “We need to stay true to our Oregon roots and continue to be a clean, green, granola-eating state.”

Cascadia Labs is conducting the pesticide and cannabinoid analytics for all submissions and Phylos Bioscience will perform testing for the winners. According to Julie Austin, operations manager at Cascadia Labs, pesticide testing for the Oregon list of analytes was of course a requirement. “Some of the samples submitted had previous tests from us or from other accredited labs, but if they didn’t have those results we did offer a comprehensive pesticide test,” says Austin. The competition’s fee for submission includes the potency and terpenes analysis.

Jeremy Sackett, director of operations at Cascadia Labs, says they test for 11 cannabinoids and 21 terpenes. The samples are divided into groups of THC-dominant samples, CBD-dominant samples and samples with a 1:1 ratio of the two. “The actual potency data will be withheld from judges and competitors until the day of the event,” says Sackett. “We are data driven scientists, but this time we want to have a little fun and bring the heart of this competition back to the good old days: when quality cannabis was gauged by an experience of the senses, not the highest potency number.” The event will take place on May 12^th at Revolution Hall in Portland, Oregon. Click here to get tickets to the event.

March 21, 2017

OLCC Issues First Recreational Cannabis Recall for Oregon

By Aaron G. Biros

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On March 18^th, the Oregon Liquor Control Commission (OLCC) issued its first recall for recreational cannabis products. The recall, according to the press release, occurred because an unnamed wholesaler sent cannabis products to a retailer before the pesticide test results were entered into the OLCC Cannabis Tracking System (CTS).

The cannabis grown at Emerald Wave Estate, LLC is said to fail a test for pyrethrins exceeding the Oregon Health Authority (OHA) action level (the action level for pyrethrins is 1 ppm). Pyrethrins are a class of insecticides derived from the chrysanthemum flower. Their toxicity varies a lot depending on exactly what organic compound was used, but has an acute toxicity level that is cause for concern. When exposed to high levels of pyrethrins, people have reported symptoms similar to asthma. Generally, pyrethrins have a low chronic toxicity for humans.

The retailer, Buds 4 U LLC, located in Mapleton, OR, issued a voluntary recall for 82.5 grams of the strain Blue Magoo sold between March 8^th and 10^th. After finding the failed test results in the CTS, the retailer immediately contacted the OLCC. According to The Portland Tribune, OLCC spokesman Mark Pettinger says the retailer was very cooperative in immediately notifying the OLCC. “The retailer was great,” says Pettinger. “They get the gold star.” The Portland Tribune also says the wholesaler who shipped the cannabis prior to test results being entered is Cascade Cannabis Distributing of Eugene. That mistake could be a violation of Oregon’s regulations, leading to a 10-day closure and up to a $1,650 fine.

According to the press release, the rest of the nine pounds in the batch is on hold “pending the outcome of an additional pesticide retest.” The OLCC encourages consumers to check if their products have the license and product numbers detailed in the press release. They advise consumers who did purchase the affected cannabis to dispose of the product or return it to the retailer. The press release also mentions that they have not received any reports of illness related to the tainted cannabis.

February 21, 2017

From The Lab

QuEChERS 101

By Danielle Mackowsky

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Sample preparation experts and analytical chemists are quick to suggest QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) to cannabis laboratories that are analyzing both flower and edible material for pesticides, mycotoxins and cannabinoid content. Besides having a quirky name, just what makes QuEChERS a good extraction technique for the complicated matrices of cannabis products? By understanding the chemistry behind the extraction and the methodology’s history, cannabis laboratories can better implement the technology and educate their workforce.

QuEChERS salt blends can be packed into mylar pouches for use with any type of centrifuge tubes

In 2003, a time when only eight states had legalized the use of medical cannabis, a group of four researchers published an article in the Journal of AOAC International that made quite the impact in the residue monitoring industry. Titled Fast and Easy Multiresidue Method Employing Acetonitrile Extraction/Partitioning and “Dispersive Solid-Phase Extraction” for the Determination of Pesticide Residues in Produce, Drs. Michael Anastassiades, Steven Lehotay, Darinka Štajnbaher and Frank Schenck demonstrate how hundreds of pesticides could be extracted from a variety of produce samples through the use of two sequential steps: an initial phase partitioning followed by an additional matrix clean up. In the paper’s conclusion, the term QuEChERS was officially coined. In the fourteen years that have followed, this article has been cited over 2800 times. Subsequent research publications have demonstrated its use in matrices beyond food products such as biological fluids, soil and dietary supplements for a plethora of analytes including phthalates, pharmaceutical compounds and most recently cannabis.

QuEChERS salts can come prepacked into centrifuge tubes

The original QuEChERS extraction method utilized a salt blend of 4 g of magnesium sulfate and 1 g of sodium chloride. A starting sample volume of 10 g and 10 mL of acetonitrile (ACN) were combined with the above-mentioned salt blend in a centrifuge tube. The second step, dispersive solid phase extraction (dSPE) cleanup, included 150 mg of magnesium sulfate and 25 mg of primary secondary amine (PSA). Subsequent extraction techniques, now known as AOAC and European QuEChERS, suggested the use of buffered salts in order to protect any base sensitive analytes that may be critical to one’s analysis. Though the pH of the extraction solvent may differ, all three methods agree that ACN should be used as the starting organic phase. ACN is capable of extracting the broadest range of analytes and is compatible with both LC-MS/MS and GC-MS systems. While ethyl acetate has also been suggested as a starting solvent, it is incompatible with LC-MS/MS and extracts a larger amount of undesirable matrix components in the final aliquot.

All laboratories, including cannabis and food safety settings, are constantly looking for ways to decrease their overhead costs, batch out the most samples possible per day, and keep their employees trained and safe. It is not a stretch to say that QuEChERS revolutionized the analytical industry and made the above goals tangible achievements. In the original publication, Anastassiades et al. established that recoveries of over 85% for pesticides residues were possible at a cost as low as $1 per ten grams of sample. Within forty minutes, up to twelve samples were fully extracted and ready to be analyzed by GC-MS, without the purchase of any specialized equipment. Most importantly, no halogenated solvents were necessary, making this an environmentally conscious concept. Due to the nature of the cannabis industry, laboratories in this field are able to decrease overall solvent usage by a greater amount than what was demonstrated in 2003. The recommended starting sample for cannabis laboratories is only one gram of flower, or a tenth of the starting volume that is commonly utilized in the food safety industry. This reduction in sample volume then leads to a reduction in acetonitrile usage and thus QuEChERS is a very green extraction methodology.

The complexity of the cannabis matrix can cause great extraction difficulties if proper techniques are not used

As with any analytical method, QuEChERS is not perfect or ideal for every laboratory setting. Challenges remain in the cannabis industry where the polarity of individual pesticides monitored in some states precludes them from being amenable to the QuEChERS approach. For cannabis laboratories looking to improve their pesticide recoveries, decrease their solvent usage and not invest their resources into additional bench top equipment, QuEChERS is an excellent technique to adopt. The commercialization of salt blends specific for cannabis flowers and edibles takes the guesswork out of which products to use. The growth of cannabis technical groups within established analytical organizations has allowed for better communication among scientists when it comes to best practices for this complicated matrix. Overall, it is definitely worth implementing the QuEChERS technique in one’s cannabis laboratory in order to streamline productivity without sacrificing your results.

January 23, 2017

Green Man Cannabis Recalls Due to Pesticide Residue Detection

By Aaron G. Biros

2 Comments

Denver-based Green Man Cannabis last week voluntarily recalled batches of cannabis sold to both medical patients and recreational consumers. The recall comes after the discovery of off-label pesticides during inspections in both dry-flower cannabis and infused products.

According to the Denver Department of Environmental Health (DEH), the products have labels that list an OPC License number of 403-00738, 403-00361, or 403R-00201. The cannabis in question is not a specific batch, rather, “All plant material and derived products originating from these cultivation facilities are subject to the recall.” The DEH’s statement includes contact information for the company (email: recall@greenmancannabis.com) and the DEH Public Health Inspections Division (email: phicomments@denvergov.org or 720-913-1311).

The DEH statement does not mention which pesticides were detected or the levels at which they were detected. Christian Hagaseth, founder of Green Man Cannabis, says the chemical detected was Myclobutanil. “We had used Eagle 20 in the past, [the pesticide that contains Myclobutanil] but we stopped using it as soon as it was banned,” says Hagaseth. “The DEH found the residues in the growing environment so we immediately performed a voluntary recall.” Green Man has three cultivation facilities, one of which they suspect is contaminated from pesticides sprayed a few years ago.

Christian Hageseth, founder of Green Man Cannabis

As far as corrective actions being taken, Hagaseth says they are doing a thorough cleaning and sanitation in two of their grows and a complete remediation plan in the suspected contaminated grow. “This was a good learning experience- the key takeaway for us is we need to clean these environments more consistently,” says Hagaseth. “I am grateful that the system is working; public health and environmental safety are being looked after here.” Hagaseth says the facility in question was operating almost without interruption since 2009, but they adjusted and learned to implement preventative actions following the recall.

The DEH says there have been zero reports of illness related to the recall. “The possible health impact of consuming marijuana products with unapproved pesticide residues is unknown,” the statement reads. “Short and long-term health impacts may exist depending on the specific product, duration, frequency, level of exposure and route of exposure.” The DEH advises consumers that may be concerned to reach out to their physician.

The DEH performs routine inspections of cannabis infused product manufacturers and retail locations in Denver, as well as investigating complaints. “I am sorry that it happened to us, but I am happy the system is working and we are more than happy to comply,” says Hagaseth.