Tag Archives: analytical testing

February 20, 2018

An Insider’s View: How Labs Conduct Cannabis Mold Testing

By Swetha Kaul, PhD

As both recreational and medical cannabis legalization continues to progress across the country, each state is tasked with developing regulatory requirements to ensure that customers and patients receive clean cannabis for consumption. This requires cannabis to undergo laboratory testing that analyzes the presence of microbial impurities including yeast and mold.

Some states, such as Colorado, Nevada, Maine, Illinois and Massachusetts use total yeast and mold count testing (TYMC) and set a maximum yeast and mold count threshold that cultivators must fall below. Other states, such as California, require the detection of species-specific strains of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which requires analyzing the DNA of a cannabis sample through polymerase chain reaction testing, also known as PCR.

Differences in state regulations can lead to different microbiological techniques implemented for testing.Before diving in further, it is important to understand the scientific approach. Laboratory testing requirements for cannabis can be separated into two categories: analytical chemistry methods and microbiological methods.

Analytical chemistry is the science of qualitatively and quantitatively determining the chemical components of a substance, and usually consists of some kind of separation followed by detection. Analytical methods are used to uncover the potency of cannabis, analyze the terpene profile and to detect the presence of pesticides, chemical residues, residuals solvents, heavy metals and mycotoxins. Analytical testing methods are performed first before proceeding to microbiological methods.

Petri dish containing the fungus Aspergillus flavus. It produces carcinogenic aflatoxins, which can contaminate certain foods and cause aspergillosis, an invasive fungal disease.
Photo courtesy of USDA ARS & Peggy Greb.

Microbiological methods dive deeper into cannabis at a cellular level to uncover microbial impurities such as yeast, mold and bacteria. The techniques utilized in microbiological methods are very different from traditional analytical chemistry methods in both the way they are performed and target of the analysis. Differences in state regulations can lead to different microbiological techniques implemented for testing. There are a variety of cell and molecular biology techniques that can be used for detecting microbial impurities, but most can be separated into two categories:

Methods to determine total microbial cell numbers, which typically utilizes cell culture, which involves growing cells in favorable conditions and plating, spreading the sample evenly in a container like a petri dish. The total yeast and mold count (TYMC) test follows this method.
Molecular methods intended to detect specific species of mold, such as harmful aspergillus mold strains, which typically involves testing for the presence of unique DNA sequences such as Polymerase Chain Reaction (PCR).

Among states that have legalized some form of cannabis use and put forth regulations, there appears to be a broad consensus that the laboratories should test for potency (cannabinoids concentration), pesticides (or chemical residues) and residual solvents at a minimum. On the other hand, microbial testing requirements, particularly for mold, appear to vary greatly from state to state. Oregon requires random testing for mold and mildew without any details on test type. In Colorado, Nevada, Maine, Illinois and Massachusetts, regulations explicitly state the use of TYMC for the detection of mold. In California, the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which are difficult to differentiate on a plate and would require a DNA-based approach. Since there are differences in costs associated and data produced by these methods, this issue will impact product costs for cultivators, which will affect cannabis prices for consumers.

August 24, 2016

The Practical Chemist

Building the Foundation of Medical Cannabis Testing – Understanding the Use of Standards and Reference Materials – Part 1

By Joe Konschnik

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In previous articles, you may recall that Amanda Rigdon, one our contributing authors, stated that instrument calibration is the foundation of all data quality. In this article, I would like to expand on that salient point. A properly calibrated instrument will, in fact, produce reliable data. It is the foundation we build our data upon. All foundations are comprised of building blocks, and our laboratory is no exception. If we take this analogy further, the keystone to the laboratory foundation, the stone that all data relies upon, is the analytical reference material. Proper calibration means that it is based on a true, accurate value. That is what the reference material provides. In this article, I would like to expand on the use and types of reference materials in analytical testing.

To develop sound analytical data, it is important to understand the significance of reference materials and how they are properly used. The proper selection and use of reference materials ensures the analytical certainty, traceability and comparability necessary to produce scientifically sound data. First, let’s take a moment to define the types of commonly used reference materials. According to the International Vocabulary of Metrology (VIM), a Reference Standard (RS) is something that is reused to measure against, like a balance or a set of weights. A Reference Material (RM) is a generic term. It is described as something that is prepared using a RS that is homogeneous, stable and is consumed during its use for measurement. An example of an RM is the solutions used to construct a calibration curve, often referred to as calibration standards, on your GC or LC. Due to the current state of cannabis testing, reference materials can be hard to find and, even more critical, variable in their accuracy to a known reference standard. Sometimes this is not critical, but when quantifying an unknown, it is paramount.

RMs can be either quantitative or qualitative. Qualitative RMs verify the identity and purity of a compound. Quantitative RMs, on the other hand, provide a known concentration, or mass, telling us not only what is present, and its purity, but also how much. This is typically documented on the certificate that accompanies the reference material, which is provided by the producer or manufacturer. The certificate describes all of the properties of the starting materials and steps taken to prepare the RM. For testing requirements, like potency, pesticides, etc., where quantitation is expected, it is important to use properly certified quantitative RMs.

Now, the pinnacle of reference materials is the Certified Reference Material (CRM). VIM defines a Certified Reference Material (CRM) as an RM accompanied by documentation issued by an authoritative body and provides one or more specified property values, with associated uncertainties and traceability using valid procedures. A CRM is generally recognized as providing the highest level of traceability and accuracy to a measurement – the strongest keystone you can get for your foundation. It is also important to recognize that the existence of a certificate does not make a reference material a CRM. It is the process used in manufacturing that makes it a CRM, and these are typically accreditations earned by specific manufacturers who have invested on this level of detail.

Now that we understand the types of reference materials we can choose, in the next article of this series we will describe what a CRM provider must do to ensure the material and how we can use them to develop reliable data. Without properly formulated and prepared CRMs, instrument calibration and the use of internal standards are less effective at ensuring the quality of your data.

If you have any questions please contact me, Joe Konschnik at (800) 356-1688 ext. 2002 by phone, or email me at joe.konschnik@restek.com.

May 4, 2016

AOCS Highlights Cannabis Lab Standards, Extraction Technology

By Aaron G. Biros

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The American Oil Chemists’ Society (AOCS) held its annual conference in Salt Lake City this week, with a track focused on cannabis testing and technology. Cynthia Ludwig, director of technical services at AOCS and member of the advisory panel to The Emerald Test, hosted the two-day event dedicated to all things extraction technology and analytical testing of cannabis.

Highlights in the discussion surrounding extraction technologies for the production of cannabis concentrates included the diversity of concentrate products, solvent selection for different extraction techniques and the need for cleaning validation in extraction equipment. Jerry King, Ph.D., research professor at the University of Arkansas, began the event with a brief history of cannabis processing, describing the physical morphologies in different types of extraction processes.

J. Michael McCutcheon presents a history of cannabis in medicine

Michael McCutcheon, research scientist at Eden Labs, laid out a broad comparison of different extraction techniques and solvents in use currently. “Butane is a great solvent; it’s extremely effective at extracting active compounds from cannabis, but it poses considerable health, safety and environmental concerns largely due to its flammability,” says McCutcheon. He noted it is also very difficult to get USP-grade butane solvents so the quality can be lacking. “As a solvent, supercritical carbon dioxide can be better because it is nontoxic, nonflammable, readily available, inexpensive and much safer.” The major benefit of using supercritical carbon dioxide, according to McCutcheon, is its ability for fine-tuning, allowing the extractor to be more selective and produce a wider range of product types. “By changing the temperature or pressure, we can change the density of the solvent and thus the solubility of the many different compounds in cannabis.” He also noted that, supercritical carbon dioxide exerts tremendous pressure, as compared to hydrocarbon solvents, so the extraction equipment needs to be rated to a higher working pressure and is generally more expensive.

John A. Mackay, Ph.D., left at the podium and Jerry King, Ph.D., on the right

John A. Mackay, Ph.D., senior director of strategic technologies at Waters Corporation, believes that cannabis processors using extraction equipment need to implement cleaning SOPs to prevent contamination. “There is currently nothing in the cannabis industry like the FDA CMC draft for the botanical industry,” says Mackay. “If you are giving a child a high-CBD extract and it was produced in equipment that was previously used for another strain that contains other compounds, such as CBG, CBD or even traces of THC extract, there is a high probability that it will still contain these compounds as well as possibly other contaminants unless it was properly cleaned.” Mackay’s discussion highlighted the importance of safety and health for workers throughout the workflow as well as the end consumer.

Jeffrey Raber, Ph.D., chief executive officer of The Werc Shop, examined different testing methodologies for different applications, including potency analyses with liquid chromatography. His presentation was markedly unique in proposing a solution to the currently inconsistent classification system for cannabis strains. “We really do not know what strains cause what physiological responses,” says Raber. “We need a better classification system based on chemical fingerprints, not on baseless names.” Raber suggests using a chemotaxonomic system to identify physiological responses in strains, noting that terpenes could be the key to these responses.

Cynthia Ludwig welcomes attendees to the event.

Dylan Wilks, chief scientific officer at Orange Photonics, discussed the various needs in sample preparation for a wide range of products. He focused on sample prep and variation for on-site potency analysis, which could give edibles manufacturers crucial quality assurance tools in process control. Susan Audino, Ph.D., chemist and A2LA assessor, echoed Wilks’ concerns over sample collection methods. “Sampling can be the most critical part of the analysis and the sample size needs to be representative of the batch, which is currently a major issue in the cannabis industry,” says Audino. “I believe that the consumer has a right to know that what they are ingesting is safe.” Many seemed to share her sentiment about the current state of the cannabis testing industry. “Inadequate testing is worse than no testing at all and we need to educate the legislators about the importance of consumer safety.”

46 cannabis laboratories participated in The Emerald Test’s latest round of proficiency testing for potency and residual solvents. Cynthia Ludwig sits on the advisory panel to give direction and industry insights, addressing specific needs for cannabis laboratories. Kirsten Blake, director of sales at Emerald Scientific, believes that proficiency testing is the first step in bringing consistency to cannabis analytics. “The goal is to create some level of industry standards for testing,” says Blake. Participants in the program will be given data sets, judged by a consensus mean, so labs can see their score compared to the rest of the cannabis testing industry. Proficiency tests like The Emerald Test give labs the ability to view how consistent their results are compared to the industry’s results overall. According to Ludwig, the results were pleasantly surprising. “The results were better than expected across the board; the vast majority of labs were within the acceptable range,” says Ludwig. The test is anonymous so individual labs can participate freely.

The AOCS cannabis working groups and expert panels are collaborating with Emerald Scientific to provide data analytics reports compliant with ISO 13528. “In the absence of a federal program, we are trying to provide consistency in cannabis testing to protect consumer safety,” says Ludwig. At the AOCS annual meeting, many echoed those concerns of consumer safety, proposing solutions to the current inconsistencies in testing standards.

April 4, 2016

The Practical Chemist

Easy Ways to Generate Scientifically Sound Data

By Amanda Rigdon

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I have been working with the chemical analysis side of the cannabis industry for about six years, and I have seen tremendous scientific growth on the part of cannabis labs over that time. Based on conversations with labs and the presentations and forums held at cannabis analytical conferences, I have seen the cannabis analytical industry move from asking, “how do we do this analysis?” to asking “how do we do this analysis right?” This change of focus represents a milestone in the cannabis industry; it means the industry is growing up. Growing up is not always easy, and that is being reflected now in a new focus on understanding and addressing key issues such as pesticides in cannabis products, and asking important questions about how regulation of cannabis labs will occur.

While sometimes painful, growth is always good. To support this evolution, we are now focusing on the contribution that laboratories make to the safety of the cannabis consumer through the generation of quality data. Much of this focus has been on ensuring scientifically sound data through regulation. But Restek is neither a regulatory nor an accrediting body. Restek is dedicated to helping analytical chemists in all industries and regulatory environments produce scientifically sound data through education, technical support and expert advice regarding instrumentation and supplies. I have the privilege of supporting the cannabis analytical testing industry with this goal in mind, which is why I decided to write a regular column detailing simple ways analytical laboratories can improve the quality of their chromatographic data right now, in ways that are easy to implement and are cost effective.

Anyone with an instrument can perform chromatographic analysis and generate data. Even though results are generated, these results may not be valid. At the cannabis industry’s current state, no burden of proof is placed on the analytical laboratory regarding the validity of its results, and there are few gatekeepers between those results and the consumer who is making decisions based on them. Even though some chromatographic instruments are super fancy and expensive, the fact is that every chromatographic instrument – regardless of whether it costs ten thousand or a million dollars – is designed to spit out a number. It is up to the chemist to ensure that number is valid.

In the first couple of paragraphs of this article, I used terms to describe ‘good’ data like ‘scientifically-sound’ or ‘quality’, but at the end of the day, the definition of ‘good’ data is valid data. If you take the literal meaning, valid data is justifiable, logically correct data. Many of the laboratories I have had the pleasure of working with over the years are genuinely dedicated to the production of valid results, but they also need to minimize costs in order to remain competitive. The good news is that laboratories can generate valid scientific results without breaking the bank.

In each of my future articles, I will focus on one aspect of valid data generation, such as calibration and internal standards, explore it in practical detail and go over how that aspect can be applied to common cannabis analyses. The techniques I will be writing about are applied in many other industries, both regulated and non-regulated, so regardless of where the regulations in your state end up, you can already have a head start on the analytical portion of compliance. That means you have more time to focus on the inevitable paperwork portion of regulatory compliance – lucky you! Stay tuned for my next column on instrument calibration, which is the foundation for producing quality data. I think it will be the start of a really good series and I am looking forward to writing it.