Tag Archives: high performance liquid chromatography

Orange Photonics Introduces Terpenes+ Module in Portable Analyzer

By Aaron G. Biros
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Last week at the National Cannabis Industry Association’s (NCIA) Cannabis Business Summit, Orange Photonics unveiled their newest product added to their suite of testing instruments for quality assurance in the field. The Terpenes+ Module for the LightLab Cannabis Analyzer, which semi-quantitatively measures terpenes, Cannabichromene (CBC) and degraded THC, adds three new chemical analyses to the six cannabinoids it already reports.

CBC, a cannabinoid typically seen in hemp and CBD-rich plants, has been linked to some potentially impactful medical applications, much like the findings regarding the benefits of CBD. The module that tests for it, along with terpenes and degraded THC, can be added to the LightLab without any changes to hardware or sample preparation.

Dylan Wilks, chief technology officer of Orange Photonics
Dylan Wilks, chief technology officer of Orange Photonics

According to Dylan Wilks, chief technology officer of Orange Photonics, this could be a particularly useful tool for distillate producers looking for extra quality controls. Cannabis distillates are some of the most prized cannabis products around, but the heat used to create them can also create undesirable compounds,” says Wilks. “Distillate producers can see potency drop more than 25% if their process isn’t optimized”. With this new Terpenes+ Module, a distillate producer could quantify degraded THC content and get an accurate reading for their QC/QA department.

We spoke with Stephanie McArdle, president of Orange Photonics, to learn more about their instruments designed for quality assurance for growers and extractors alike.

Stephanie McArdle, president of Orange Photonics
Stephanie McArdle, president of Orange Photonics

According to McArdle, this could help cultivators and processors understand and value their product when terpene-rich products are the end goal. “Rather than try to duplicate the laboratory analysis, which would require expensive equipment and difficult sample preparation, we took a different approach. We report all terpenes as a single total terpene number,” says McArdle. “The analyzer only looks for monoterpenes (some common monoterpenes are myrcene, limonene and alpha-pinene), and not sesquiterpenes (the other major group of cannabis terpenes, such as Beta- Caryophyllene and Humulene) so the analysis is semi-quantitative. What we do is measure the monoterpenes and make an assumption that the sesquiterpenes are similar to an average cannabis plant to calculate a total terpene content.” She says because roughly 80% of terpenes found in cannabis are monoterpenes, this should produce accurate results, though some exotic strains may not result in accurate terpene content using this method.

The LIghtLab analyzer on the workbench
The LIghtLab analyzer on the workbench

As growers look to make their product unique in a highly competitive market, many are looking at terpenes as a source of differentiation. There are a variety of areas where growers can target higher terpene production, McArdle says. “During production, a grower may want to select plants for growing based on terpene content, or adjust nutrient levels, lighting, etc. to maximize terpenes,” says McArdle. “During the curing process, adjusting the environmental conditions to maximize terpene content is highly desirable.” Terpenes are also beginning to get recognized for their potential medical and therapeutic values as well, notably as an essential piece in the Entourage Effect. “Ultimately, it comes down to economics – terpene rich products have a higher market value,” says McArdle. “If you’re the grower, you want to prove that your product is superior. If you’re the buyer, you want to ensure the product you buy is high quality before processing it into other products. In both cases, knowing the terpene content is critical to ensuring you’re maximizing profits.”

Orange Photonics’ LightLab operates very similarly to instruments you might find in a cannabis laboratory. Many cannabis testing labs use High Performance Liquid Chromatography (HPLC) to analyze hemp or cannabis samples. “The primary difference between LightLab and an HPLC is that we operate at lower pressures and rely on spectroscopy more heavily than a typical HPLC analysis does,” says McArdle. “Like an HPLC, LightLab pushes an extracted cannabis sample through a column. The column separates the cannabinoids in the sample by slowing down cannabinoids by different amounts based on their affinity to the column.” McArdle says this is what allows each cannabinoid to exit the column at a different time. “For example, CBD may exit the column first, then D9THC and so on,” says McArdle. “Once the column separates the cannabinoids, they are quantified using optical spectroscopy- basically we are using light to do the final quantification.”

Lauren Pahnke
From The Lab

Centrifugal Partition Chromatography Paves the Way for Safer, More Standardized Cannabidiol Drugs

By Lauren Pahnke
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Lauren Pahnke

Imagine this: you are taking medication for cancer pain. One day, it works perfectly. The next, you feel no relief. On some days, you need to take three doses just to get the same effect as one. Your doctor can’t be completely positive how much active ingredient each dose contains, so you decide for yourself how much medication to take.

Doesn’t seem safe, right? It is crucial that doctors know exactly what they are prescribing to their patients. They must know that their patients are receiving the exact same dose of medication in their prescription each time they take it, and that their medication contains only the intended ingredients.

consistency is key to creating products that are safe for consumers.In the cannabis industry, lack of certainty on these important factors is a major problem for drug manufacturers as they attempt to incorporate cannabidiol (CBD), a compound found in cannabis that has no psychoactive effects but many medical benefits, into pharmaceutical drugs.

When using these compounds as medications, purity is essential. Cannabis contains a wide variety of compounds. Delta-9 tetrahydrocannabinol (THC) is the most well-known compound and its main psychoactive one1. Safety regulations dictate that consumers know exactly what they are getting when they take a medication. For example, their CBD-based medications should not contain traces of THC.

The cannabis industry greatly needs a tool to ensure the consistent extraction and isolation of compounds. In 2017, the cannabis industry was worth nearly $10 billion, and it is expected to grow $57 billion more in the next decade2. As legalization of medical cannabis expands, interest in CBD pharmaceuticals is likely to grow.

If compounds such as CBD are going to be used in pharmaceutical drugs, consistency is key to creating products that are safe for consumers.

CBD’s Potential

CBD is a non-psychoactive compound that makes up 40 percent of cannabis extracts1. It is great for medical applications because it does not interfere with motor or psychological function. Researchers have found it particularly effective for managing cancer pain, spasticity in multiple sclerosis, and specific forms of epilepsy3.

Figure 1: The chemical structure of cannabidiol.
Figure 1: The chemical structure of cannabidiol.

Other compounds derived from cannabis, such as cannabichromene (CBC) and cannabigerol (CBG), may also be beneficial compounds with medical applications. CBC is known to block pain and inflammation, and CBG is known for its use as a potential anti-cancer agent1.

Along with these compounds that provide medical benefits, there are psychoactive compounds that are used recreationally, such as THC.

“It will definitely be an advantage to have cannabis-based medications with clearly defined and constant contents of cannabinoids,” says Kirsten Müller-Vahl, a neurologist and psychiatrist at Hannover Medical School in Germany.

Creating a Standard Through Centrifugal Partition Chromatography

To obtain purified compounds from cannabis, researchers need to use technology that will extract the compounds from the plant.

Many manufacturers use some sort of chromatography technique to isolate compounds. Two popular methods are high performance liquid chromatography (HPLC) and flash chromatography. These methods have their places in the field, but they cannot be effectively and cost-efficiently scaled to isolate compounds. Instead, HPLC and flash chromatography may be better suited as analytical tools for studying the characteristics of the plant or extract. As cannabis has more than 400 chemical entities4, compound isolation is an important application.

This method is highly effective for achieving both high purity and recovery.Although molecules such as CBD can be synthesized in the lab, many companies would rather extract the compounds directly from the plant. Synthesized molecules do not result in a completely pure compound. The result, “is still a mixture of whatever cannabinoids are coming from a particular marijuana strain, which is highly variable,” says Brian Reid, chief scientific officer of ebbu, a company in Colorado that specializes in cannabis purification.

Currently, there is only one method available to researchers that completely allows them to isolate individual compounds: centrifugal partition chromatography (CPC).

The principle of CPC is similar to other liquid chromatography methods. It separates the chemical substances as the compounds in the mobile phase flow through and differentially interact with the stationary phase.

Where CPC and standard liquid chromatography differs is the nature of the stationary phase. In traditional chromatography methods, the stationary phase is made of silica or other solid particles, and the mobile phase is made of liquid. During CPC, the stationary phase is a liquid that is spun around or centrifuged to stay in place while the other liquid (mobile phase) moves through the disc. The two liquid phases, like oil and water, don’t mix. This method is highly effective for achieving both high purity and recovery. Chemists can isolate chemical components at 99 percent or higher purity with a 95 percent recovery rate5.

“CPC is ideal for ripping a single active ingredient out of a pretty complex mixture,” says Reid. “It’s the only chromatographic technique that does that well.”

The Need for Pure Compounds

High levels of purity and isolation are necessary for cannabis to be of true value in the pharmaceutical industry. Imagine relying on a medication to decrease your seizures, and it has a different effect every time. Sometimes there may be traces of psychoactive compounds. Sometimes there are too much or too little of the compound that halts your seizures. This is not a safe practice for consumers who rely on medications.“It’s hard to do studies on things you can’t control very well.”

Researchers working with cannabis desperately need a technology that can extract compounds with high purity rates. It is hard to run a study without knowing the precise amounts of compounds used. Reid uses a Gilson CPC 1000 system at ebbu for his cannabinoid research. With this technology, he can purify cannabinoids for his research and create reliable formulations. “Now that we have this methodology dialed in we can make various formulations —whether they’re water-soluble, sublingual, inhaled, you name it —with very precise ratios of cannabinoids and precise amounts of cannabinoids at the milligram level,” says Reid.

Kyle Geary, an internist at the University of Illinois at Chicago, is currently running a placebo-controlled trial of CBD capsules for Crohn’s disease. This consistent isolation is helpful for his research, as well. “Ideally, the perfect study would use something that is 100 percent CBD,” says Geary. “It’s hard to do studies on things you can’t control very well.”

The State of the Industry

While CBD is not considered a safe drug compound under federal law in the United States6, 17 states have recently passed laws that allow people to consume CBD for medical reasons7. Half of medicinal CBD users solely use the substance for treatment, a recent survey found8. As the industry quickly grows, it is crucial that consumer safety protocol keeps pace.

In June, the US Food and Drug Administration (FDA) approved the first drug that contains a purified drug substance from cannabis, Epidiolex9. Made from CBD, it is designed to treat Dravet Syndrome and Lennox-Gastaut syndrome, two rare forms of epilepsy. FDA Commissioner Scott Gottlieb said in the news release that although the FDA will work to support the development of high-quality cannabis-based products moving forward, “We are prepared to take action when we see the illegal marketing of CBD-containing products with serious, unproven medical claims. Marketing unapproved products, with uncertain dosages and formulations can keep patients from accessing appropriate, recognized therapies to treat serious and even fatal diseases.”

The industry should be prepared to implement protocols to ensure the quality of their CBD-based products. The FDA has issued warnings in recent years that some cannabinoid products it has tested do not contain the CBD levels their makers claim, and consumers should be wary of such products10. It’s hard to know when or if the FDA will begin regulating CBD-based pharmaceuticals. However, for pharma companies serious about their reputation, there is only one isolation method that creates reliable product quality: CPC.


References:

  1. Lab Manager. (2018, January 3). Cannabinoid Chemistry Infographic. Retrieved from http://www.labmanager.com/multimedia/2017/07/cannabinoid-chemistry-infographic#.WzT2e1MvyMI
  2. BDS Analytics. (2018, February 26). NEW REPORT: Worldwide spending on legal cannabis will reach $57 billion by 2027. Retrieved from https://bdsanalytics.com/press/new-report-worldwide-spending-on-legal-cannabis-will-reach-57-billion-by-2027/
  3. National Institute on Drug Abuse. (2015, June 24). The Biology and Potential Therapeutic Effects of Cannabidiol. Retrieved from https://www.drugabuse.gov/about-nida/legislative-activities/testimony-to-congress/2016/biology-potential-therapeutic-effects-cannabidiol
  4. Atakan, Z. (2012). Cannabis, a complex plant: Different compounds and different effects on individuals. Therapeutic Advances in Psychopharmacology,2(6), 241-254. doi:10.1177/2045125312457586
  5. Gilson. (n.d.). Centrifugal Partition Chromatography (CPC) Systems. Retrieved from http://www.gilson.com/en/AI/Products/80.320#.WzVB2lMvyMI
  6. Mead, A. (2017). The legal status of cannabis (marijuana) and cannabidiol (CBD) under US law. Epilepsy & Behavior, 70, 288-291.
  7. ProCon.org. (2018, May 8). 17 States with Laws Specifically about Legal Cannabidiol (CBD) – Medical Marijuana – ProCon.org. Retrieved from https://medicalmarijuana.procon.org/view.resource.php?resourceID=006473
  8. Borchardt, D. (2017, August 03). Survey: Nearly Half Of People Who Use Cannabidiol Products Stop Taking Traditional Medicines. Retrieved from https://www.forbes.com/sites/debraborchardt/2017/08/02/people-who-use-cannabis-cbd-products-stop-taking-traditional-medicines/#43889c942817
  9. U.S. Food & Drug Administration. (2018, June 25). Press Announcements – FDA approves first drug comprised of an active ingredient derived from marijuana to treat rare, severe forms of epilepsy. Retrieved from https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm611046.htm
  10. U.S. Food & Drug Administration. (2017). Public Health Focus – Warning Letters and Test Results for Cannabidiol-Related Products. Retrieved from https://www.fda.gov/newsevents/publichealthfocus/ucm484109.htm

A More Effective and Efficient Approach to Purer Cannabidiol Production Using Centrifugal Partition Chromatography

By Lauren Pahnke
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Many physicians today treat their patients with cannabidiol (CBD, Figure 1), a cannabinoid found in cannabis. CBD is more efficacious over traditional medications, and unlike delta-9 tetrahydrocannbinol (THC), the main psychoactive compound in cannabis, CBD has no psychoactive effects. Researchers have found CBD to be an effective treatment for conditions such as cancer pain, spasticity in multiple sclerosis, and Dravet Syndrome, a form of epilepsy.

CBD is still considered an unsafe drug under federal law, but to meet the medical demand, 17 states in the US recently passed laws allowing individuals to consume CBD for medical purposes. A recent survey found that half of medicinal CBD users rely on the substance by itself for treatment. As doctors start using CBD to treat more patients, the demand for CBD is only expected to rise, and meeting that demand can pose challenges for manufacturers who are not used to producing such high quantities of CBD. Furthermore, as CBD-based drugs become more popular, the US Food and Drug Administration (FDA) will likely require manufacturers to demonstrate they can produce pure, high-quality products.

cannabidiol
Figure 1. The structure of cannabidiol, one of 400 active compounds found in cannabis.

Most manufacturers use chromatography techniques such as high performance liquid chromatography (HPLC) or flash chromatography to isolate compounds from natural product extracts. While these methods are effective for other applications, they are not, however, ideal for CBD isolate production. Crude cannabis oil contains some 400 potentially active compounds and requires pre-treatment prior to traditional chromatography purification. Both HPLC and flash chromatography also require silica resin, an expensive consumable that must be replaced once it is contaminated due to irreversible absorption of compounds from the cannabis extract. All of these factors limit the production capacity for CBD manufacturers.

Additionally, these chromatography methods use large quantities of solvents to elute natural compounds, which negatively impacts the environment.

A Superior Chromatography Method

Centrifugal partition chromatography (CPC) is an alternative chromatography method that can help commercial CBD manufacturers produce greater quantities of pure CBD more quickly and cleanly, using fewer materials and generating less toxic waste. CPC is a highly scalable CBD production process that is environmentally and economically sustainable.

The mechanics of a CPC run are analogous to the mechanics of a standard elution using a traditional chromatography column. While HPLC, for instance, involves eluting cannabis oil through a resin-packed chromatography column, CPC instead elutes the oil through a series of cells embedded into a stack of rotating disks. These cells contain a liquid stationary phase composed of a commonly used fluid such as water, methanol, or heptane, which is held in place by a centrifugal force. A liquid mobile phase migrates from cell to cell as the stacked disks spin. Compounds with greater affinity to the mobile phase are not retained by the stationary phase and pass through the column faster, whereas compounds with a greater affinity to the stationary phase are retained and pass through the column slower, thereby distributing themselves in separate cells (Figure 2).

Figure 2- CPC
Figure 2. How CPC isolates compounds from complex, natural mixtures. As the column spins, the mobile phase (yellow) moves through each cell in series. The compounds in the mobile phase (A, B, and C) diffuse into the stationary phase (blue) at different rates according to their relative affinities for the two phases.

A chemist can choose a biphasic solvent system that will optimize the separation of a target compound such as CBD to extract relatively pure CBD from a cannabis extract in one step. In one small-scale study, researchers injected five grams of crude cannabis oil low in CBD content into a CPC system and obtained 205 milligrams of over 95% pure CBD in 10 minutes.

Using a liquid stationary phase instead of silica imbues CPC with several time and cost benefits. Because natural products such as raw cannabis extract adhere to silica, traditional chromatography columns must be replaced every few weeks. On the other hand, a chemist can simply rinse out the columns in CPC and reuse them. Also, unlike silica columns, liquid solvents such as heptane used in CPC methods can be distilled with a rotary evaporator and recycled, reducing costs.

Environmental Advantages of CPC

The solvents used in chromatography, such as methanol and acetonitrile, are toxic to both humans and the environment. Many environmentally-conscious companies have attempted to replace these toxic solvents with greener alternatives, but these may come with drawbacks. The standard, toxic solvents are so common because they are integral for optimizing purity. Replacing a solvent with an alternative could, therefore, diminish purity and yield. Consequently, a chemist may need to perform additional steps to achieve the same quality and quantity achievable with a toxic solvent. This produces more waste, offsetting the original intent of using the green solvent.

CPC uses the same solvents as traditional chromatography, but it uses them in smaller quantities. Furthermore, as previously mentioned, these solvents can be reused. Hence, the method is effective, more environmentally-friendly, andeconomically feasible.

CPC’s Value in CBD Production

As manufacturers seek to produce larger quantities of pure CBD to meet the demand of patients and physicians, they will need to integrate CPC into their purification workflows. Since CPC produces a relativelyduct on a larger scale, it is equipped to handle the high-volume needs of a large manufacturer. Additionally, because it extracts more CBD from a given volume of raw cannabis extract, and does not use costly silica or require multiple replacement columns, CPC also makes the process of industrial-scale CBD production economically sustainable. Since it also uses significantly less solvent than traditional chromatography, CPC makes it financially feasible to make the process of producing CBD more environmentally-friendly.

Suggested Reading:

CPC 250: Purification of Cannabidiol from Cannabis sativa

Introduction to Centrifugal Partition Chromatography

Shimadzu Launches Cannabis Analyzer for Potency

By Aaron G. Biros
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On Monday, March 6th, Shimadzu Scientific Instruments, a leading laboratory analytical instrumentation manufacturer, announced the launch of a new product focused on cannabis, according to a press release. Their Cannabis Analyzer for Potency is essentially a high-performance liquid chromatograph (HPLC) packaged with integrated hardware, software, workflows and all the supplies. The supplies include an analytical column, guard columns, mobile phase and a CRM standard mixture.canAnalyzerImg1

The instrument is designed to test for 11 cannabinoids in less time and with greater ease than traditional HPLC instruments. In the press release, they claim “operators are now able to produce accurate results with ease, regardless of cannabis testing knowledge or chromatography experience.” One very unique aspect of the instrument is the lack of experience required to run it, according to Bob Clifford, general manager of marketing at Shimadzu. “We have our typical chromatography software [LabSolutions] with an overlay that allows the user to analyze a sample in three simple steps,” says Clifford. Those in the cannabis industry that have a background in plant science, but not analytical chemistry, could run potency analyses on the instrument with minimal training. “This overlay allows ease of use for those not familiar with chromatography software,” says Clifford.

An overlay of a flower sample with the standards supplied in the High-Sensitivity Method package.
An overlay of a flower sample with the standards supplied in the High-Sensitivity Method package.

The instrument can determine cannabinoid percentages per dry weight in flower concentrates and edibles. “Once you open the software, it will get the flow rate started, heat the column up and automatically begin to prep for analysis,” says Clifford. Before the analysis begins, information like the sample ID number, sample name, sample weight, extraction volume and dilution volume are entered. After the analysis is complete all the test results are reported for each sample.

Because laboratories wouldn’t have to develop quantitative testing methodology, they argue this instrument would save a lot of time in the lab. “After one day of installation and testing, users are equipped with everything they need to obtain cannabis potency results,” states the press release. According to Clifford, method development for potency analysis in-house can take some labs up to three months. “We can bring this instrument to the lab and have it ready for testing almost immediately,” says Clifford. “The methods for this instrument were developed by a team of twenty scientists working on different platforms at our Innovation Center and was tested for ruggedness, repeatability and quantitative accuracy.”

Screenshots from the software on the instrument
Screenshots from the software on the instrument

The instrument’s workflow is designed to meet three methods of analysis depending on testing needs. The High Throughput method package can determine quantities of ten cannabinoids with less than eight minutes per sample. The method was developed in collaboration with commercial testing laboratories. The High Sensitivity method package adds THCV to that target analyte list with ten minutes per analysis. The method provides the sharpest chromatographic peaks and best sensitivity. The High Resolution method package offers full baseline resolution for those 11 cannabinoids in less than 30 minutes per analysis and the ability to add cannabinoids to that target list if regulations change.

The press release states the interface should allow users to reduce the number of steps needed in the analysis and simplify the workflow. The instrument comes with a three-year warranty, preventative maintenance plan and lifetime technical support.

The Practical Chemist

Appropriate Instrumentation for the Chemical Analysis of Cannabis and Derivative Products: Part 1

By Rebecca Stevens
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Election Day 2016 resulted in historic gains for state level cannabis prohibition reform. Voters in California, Maine, Massachusetts and Nevada chose to legalize adult use of Cannabis sp. and its extracts while even traditionally conservative states like Arkansas, Florida, Montana and North Dakota enacted policy allowing for medical use. More than half of the United States now allows for some form of legal cannabis use, highlighting the rapidly growing need for high quality analytical testing.

For the uninitiated, analytical instrumentation can be a confusing mix of abbreviations and hyphenation that provides little obvious information about an instrument’s capability, advantages and disadvantages. In this series of articles, my colleagues and I at Restek will break down and explain in practical terms what instruments are appropriate for a particular analysis and what to consider when choosing an instrumental technique.

Potency Analysis

Potency analysis refers to the quantitation of the major cannabinoids present in Cannabis sp. These compounds are known to provide the physiological effects of cannabis and their levels can vary dramatically based on cultivation practices, product storage conditions and extraction practices.

The primary technique is high performance liquid chromatography (HPLC) coupled to ultraviolet absorbance (UV) detection. Gas chromatography (GC) coupled to a flame ionization detector (FID) or mass spectrometry (MS) can provide potency information but suffers from issues that preclude its use for comprehensive analysis.

Pesticide Residue Analysis

Pesticide residue analysis is, by a wide margin, the most technically challenging testing that we will discuss here. Trace levels of pesticides incurred during cultivation can be transferred to the consumer both on dried plant material and in extracts prepared from the contaminated material. These compounds can be acutely toxic and are generally regulated at part per billion parts-per-billion levels (PPB).

Depending on the desired target pesticides and detection limits, HPLC and/or GC coupled with tandem mass spectrometry (MS/MS) or high resolution accurate mass spectrometry (HRAM) is strongly recommended. Tandem and HRAM mass spectrometry instrumentation is expensive, but in this case it is crucial and will save untold frustration during method development.

Residual Solvents Analysis

When extracts are produced from plant material using organic solvents such as butane, alcohols or supercritical carbon dioxide there is a potential for the solvent and any other contaminants present in it to become trapped in the extract. The goal of residual solvent analysis is to detect and quantify solvents that may remain in the finished extract.

Residual solvent analysis is best accomplished using GC coupled to a headspace sample introduction system (HS-GC) along with FID or MS detection. Solid phase microextraction (SPME) of the sample headspace with direct introduction to the GC is another option.

Terpene Profile Analysis

While terpene profiles are not a safety issue, they provide much of the smell and taste experience of cannabis and are postulated to synergize with the physiologically active components. Breeders of Cannabis sp. are often interested in producing strains with specific terpene profiles through selective breeding techniques.

Both GC and HPLC can be employed successfully for terpenes analysis. Mass spectrometry is suitable for detection as well as GC-FID and HPLC-UV.

Heavy Metals Analysis

Metals such as arsenic, lead, cadmium, chromium and mercury can be present in cannabis plant material due to uptake from the soil, fertilizers or hydroponic media by a growing plant. Rapidly growing plants like Cannabis sp. are particularly efficient at extracting and accumulating metals from their environment.

Several different types of instrumentation can be used for metals analysis, but the dominant technology is inductively coupled plasma mass spectrometry (ICP-MS). Other approaches can also be used including ICP coupled with optical emission spectroscopy (ICP-OES).

Rebecca is an Applications Scientist at Restek Corporation and is eager to field any questions or comments on cannabis analysis, she can be reached by e-mail, rebecca.stevens@restek.com or by phone at 814-353-1300 (ext. 2154)

An inductively coupled plasma torch used in MS reaches local temperatures rivaling the surface of the sun. Image by W. Blanchard, Wikimedia
An inductively coupled plasma torch used in Optical Emission Spectroscopy (OES) reaches local temperatures rivaling the surface of the sun. Image by W. Blanchard, Wikimedia
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Quality From Canada

Near Infrared, GC and HPLC Applications in Cannabis Testing

By Tegan Adams, Michael Bertone
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When a cannabis sample is submitted to a lab for testing there is a four-step process that occurs before it is tested in the instrumentation on site:

  1. It is ground at a low temperature into a fine powder;
  2. A solution is added to the ground powder;
  3. An extraction is repeated 6 times to ensure all cannabinoids are transferred into a common solution to be used in testing instrumentation.
  4. Once the cannabinoid solution is extracted from the plant matter, it is analyzed using High Pressure Liquid Chromatograph (HPLC). HPLC is the key piece of instrumentation in cannabis potency testing procedures.

While there are many ways to test cannabis potency, HPLC is the most widely accepted and recognized testing instrumentation. Other instrument techniques include gas chromatography (GC) and thin layer chromatography (TLC). HPLC is preferred over GC because it does not apply heat in the testing process and cannabinoids can then be measured in their naturally occurring forms. Using a GC, heat is applied as part of the testing process and cannabinoids such as THCA or CBDA can change form, depending on the level of heat applied. CBDA and THCA have been observed to change form at as low as 40-50C. GC uses anywhere between 150-200C for its processes, and if using a GC, a change of compound form can occur. Using HPLC free of any high-heat environments, acidic (CBDA & THCA) and neutral cannabinoids (CBD, THC, CBG, CBN and others) can be differentiated in a sample for quantification purposes.

Near Infrared

Near infrared (NIR) has been used with cannabis for rapid identification of active pharmaceutical ingredients by measuring how much light different substances reflect. Cannabis is typically composed of 5-30% cannabinoids (mainly THC and CBD) and 5-15% water. Cannabinoid content can vary by over 5% (e.g. 13-18%) on a single plant, and even more if grown indoors. Multiple NIR measurements can be cost effective for R&D purposes. NIR does not use solvents and has a speed advantage of at least 50 times over traditional methods.

The main downfall of NIR techniques is that they are generally less accurate than HPLC or GC for potency analyses. NIR can be programmed to detect different compounds. To obtain accuracy in its detection methods, samples must be tested by HPLC on ongoing basis. 100 samples or more will provide enough information to improve an NIR software’s accuracy if it is programmed by the manufacturer or user using chemometrics. Chemometrics sorts through the often complex and broad overlapping NIR absorption.

Bands from the chemical, physical, and structural properties of all species present in a sample that influences the measured spectra. Any variation however of a strain tested or water quantity observed can affect the received results. Consistency is the key to obtaining precision with NIR equipment programming. The downfall of the NIR technique is that it must constantly be compared to HPLC data to ensure accuracy.

At Eurofins Experchem , our company works with bothHPLC and NIR equipment simultaneously for different cannabis testing purposes. Running both equipment simultaneously means we are able to continually monitor the accuracy of our NIR equipment as compared to our HPLC. If a company is using NIR alone however, it can be more difficult to maintain the equipment’s accuracy without on-going monitoring.

What about Terpenes?

Terpenes are the primary aromatic constituents of cannabis resin and essential oils. Terpene compounds vary in type and concentration among different genetic lineages of cannabis and have been shown to modulate and modify the therapeutic and psychoactive effects of cannabinoids. Terpenes can be analyzed using different methods including separation by GC or HPLC and identification by Mass Spectrometry. The high-heat environment for GC analysis can again cause problems in accuracy and interpretation of results for terpenes; high-heat environments can degrade terpenes and make them difficult to find in accurate form. We find HPLC is the best instrument to test for terpenes and can now test for six of the key terpene profiles including a-Pinene, Caryophyllene, Limonene, Myrcene, B-Pinene and Terpineol.

Quality Systems

Quality systems between different labs are never one and the same. Some labs are testing cannabis under good manufacturing practices (GMP), others follow ISO accreditation and some labs have no accreditation at all.

From a quality systems’ perspective some labs have zero or only one quality system employee(s). In a GMP lab, to meet the requirements of Health Canada and the FDA, our operations are staffed in a 1:4 quality assurance to analyst ratio. GMP labs have stringent quality standards that set them apart from other labs testing cannabis. Quality standards we work with include, but are not limited to: monthly internal blind audits, extensive GMP training, yearly exams and ongoing tests demonstrating competencies.

Maintaining and adhering to strict quality standards necessary for a Drug Establishment License for pharmaceutical testing ensures accuracy of results in cannabis testing otherwise difficult to find in the testing marketplace.

Important things to know about testing

  1. HPLC is the most recommended instrument used for product release in a regulated environment.
  2. NIR is the best instrument to use for monitoring growth and curing processes for R&D purposes, only if validated with an HPLC on an ongoing basis.
  3. Quality Systems between labs are different. Regardless of instrumentation used, if quality systems are not in place and maintained, integrity of results may be compromised.
  4. GMPs comprise 25% of our labour costs to our quality department. Quality systems necessary for a GMP environment include internal audits, out of specification investigations, qualification and maintenance of instruments, systems controls and stringent data integrity standards.