Tag Archives: Spectroscopy

Cannabis Compliance Testing: Safety vs. Quality

By Vanessa Clarke, Melody Lin
1 Comment

Dr. Markus Roggen is a chemist, professor, cannabis researcher and founder & CEO of Complex Biotech Discovery Ventures (CBDV). Founder & CEO of Ascension Sciences (ASI), Tomas Skrinskas has been at the leading edge of transformative healthcare technologies, including computer assisted surgery, surgical robotics and genetic nanomedicines, for over 15 years.

Leading researchers from the cannabis industry – Dr. Markus Roggen (Complex Biotech Discovery Ventures) and Tomas Skrinskas (Ascension Sciences) – highlight the challenges facing the industry’s current compliance testing standards and the opportunities emerging from the latest developments in nanotechnology and advanced analytical testing. Here are the key insights from the discussion. 

What are the current compliance testing requirements for cannabis products? Are they sufficient in ensuring safety and quality?

In the current landscape, Canada’s compliance testing requirements are clearly laid out in the form of guidance documents. Specifically, for pesticide testing, cannabinoid concentration content in products, heavy metals, etc. Compliance testing can be roughly divided into two categories: 1) establishing the concentrations of wanted compounds, and 2) ensuring that unwanted compounds do not exceed safety limits.

In the first category, cannabinoids and terpenes are quantified. Their presence or absence is not generally forbidden but must stay within limits. For example, for material to be classified as hemp, the THC concentration cannot exceed 0.3 %wt., or a serving of cannabis edible should contain below 5 mg of THC. The second category of compliance testing focuses on pesticides, mold and heavy metals. The regulators have provided a list of substances to test for and set limits on those.

Are those rules sufficient to ensure safety and quality? Safety can only be ensured if all dangerous compounds are known and tested for. Take for example Vitamin E acetate, the substance linked to lung damage in some THC vape consumers and the EVALI outbreak. Prior to the caseload in the Fall of 2019, there were no requirements to test for it. It’s not only additives that are of concern. THC distillates often show THC concentrations of 90% plus 5% other cannabinoids. What are the last 5% of this mixture? Currently, those substances have not been identified. Are they safe? There is no concrete way to determine that.

The aforementioned guidelines have the best intentions, but do not adequately address two key obstacles the industry is currently facing: 1) what happens in practice, and 2) what can easily be audited? Making sure people follow the requirements is the challenge, and it comes down to variability of the tests. Testing has to happen on the final form of the product as well as every “batch,” but there is little guidance on how that is defined. With so much growth happening in the industry, how are these records even tracked and scrutinized?

And finally, there’s the question of quality. How do you define quality? Before establishing quantifiable quality attributes, it can’t be tested.

If compliance testing is insufficient, then why aren’t more cannabis companies testing beyond Health Canada’s requirements?

Compliance testing has always been focused on the end product, THC and CBD levels, and consumer safety. As long as cannabis companies are testing to determine this, doing further testing means added costs to the producer. There is a rush to get cannabis products to the new market because many consumers are eager to buy adult use products such as extracts or edibles, and quality is not the biggest selling point at this very moment.

However, there are unrealized advantages to advanced analytical testing that go beyond Health Canada’s requirements and that offer greater benefits to cannabis producers and product developers. Producers often see testing as an added cost to their production that is forced upon them by the regulators and will only test once the product is near completion. For cannabinoid therapeutics and nutraceuticals, advanced analytical testing is critical for determining the chemical makeup and overall quality of the formulation. This is where contract researchers, such as Ascension Sciences, come in to offer tests for nanoparticle characterization, cannabinoid concentration, dissolution profiles and encapsulation efficiency.

HPLC (high pressure liquid chromatography) instrument.

A lack of budget and awareness have prevented cannabis companies from advanced analytical testing. However, testing that goes beyond lawful requirements is an opportunity to save money and resources in the long term. This is where companies, like Complex Biotech Discovery Ventures (CBDV), offer in-process testing that provides a deep characterization and analysis of cannabis samples during every stage of product development. If tests are conducted during production, inefficiencies in the process are revealed and mistakes are spotted early on. For example, testing the spent cannabis plant material after extraction can verify if the extraction actually went through to completion. In another case, testing vape oil before it goes into the vape cartridges and packaging allows producers to detect an unacceptable THC concentration before they incur additional production costs.

Which methods are the most successful for cannabis testing?

The most effective method is the one that best determines the specific data needed to meet the desired product goal. For example, NMR Spectroscopy is paramount in assessing the quality of a cannabis sample and identifying its precise chemical composition.

HPLC (liquid/gas chromatography) is the most precise method for quantifying THC, CBD and other known cannabinoids. However, if a cannabis extractor wants to quickly verify that their oil has fully decarboxylated, then an HPLC test will likely take too long and be too expensive. In this case, IR (Infrared Spectroscopy) offers a faster and more cost-effective means of obtaining the needed data. Therefore, it ultimately depends on the needs of the producer and how well the testing instruments are maintained and operated.

What’s next in analytical testing technology? What are you working on or excited about?

In terms of compliance, regulations to standardize the testing is the hot topic at the moment. For nanotechnology and nanoparticles, the big question now is what is known as the “matrix” of the sample. In other words, what are the cannabinoids, and what else is in the sample that’s changing your results? The R&D team at Ascension Sciences is in the process of developing a standardized method for this to combat the issues mentioned earlier in the interview.

The smoke analyzer in CBDV’s lab

Ascension Sciences is also excited about characterizing nanoparticles over time to determine how cannabinoids are released and how that data can be transferred or made equivalent to consumer experiences. For example, if a formulation with quicker release, faster onset and better bioavailability is found in the lab, product development would be more efficient and effective when compared to other, more anecdotal methods.

At CBDV, the team is working on in-process analytical tools, such as decarboxylation monitoring via IR Spectroscopy and NMR Spectroscopy. CBDV is also looking at quantifying cannabis product quality. The first project currently in motion is to identify and quantify cannabinoids, terpenes, and other compounds present when vaping or smoking a joint using a smoke analyzer. 

A lack of budget and awareness have prevented cannabis companies from testing beyond what’s required by Health Canada. Compliance testing is designed to ensure safety, and for good reason, but it is currently insufficient at determining the quality, consistency and process improvements. As the above factors are necessary for the advancement of cannabis products, this is where further methods, such as advanced analytical testing, should be considered.

IR Spectrum of 2,4-Dichlorophenol in different physical states
From The Lab

Gas Chromatography/Infrared Spectroscopy: A Tool For the Analysis of Organic Compounds in Cannabis

By John F. Schneider
2 Comments
IR Spectrum of 2,4-Dichlorophenol in different physical states

Editor’s Note: The author will be teaching a 1/2 day short course on this topic at PITTCON in Philadelphia in March 2019.


The combination of gas chromatography and infrared spectroscopy (GC/IR) is a powerful tool for the characterization of compounds in complex mixtures. (1-5) Gas chromatography with mass spectroscopy detection (GC/MS) is a similar technique, but GC/MS is a destructive technique that tears apart the sample molecules during the ionization process and then these fragments are used to characterize the molecule. In GC/IR the molecules are not destroyed but the IR light produced by molecular vibrations are used to characterize the molecule. IR spectrum yields information about the whole molecule which allows the characterization of specific isomers and functional groups. GC/IR is complementary to GC/MS and the combination results in a powerful tool for the analytical chemist.

A good example of the utility of GC/IR vs GC/MS is the characterization of stereo isomers. Stereo isomers are mirror images such as a left hand and a right hand. In nature, stereo isomers are very important as one isomers will be more active then its mirror image. Stereo isomers are critical to medicinal application of cannabis and also a factor in the flavor components of cannabis.

GC/MS is good at identifying basic structure, where GC/IR can identify subtle differences in structure. GC/MS could identify a hand, GC/IR could tell you if it is a left hand or right hand. GC/MS can identify a general class of compounds, GC/IR can identify the specific isomer present.

Why GC/IR?

Gas chromatography interfaced with infrared detection (GC/IR), combines the separation ability of GC and the structural information from IR spectroscopy. GC/IR gives the analyst the ability to obtain information complementary to GC/MS. GC/IR gives the analyst the power to perform functional group detection and differentiate between similar molecular isomers that is difficult with GC/MS. Isomer specificity can be very important in flavor and medical applications.

 IR Spectrum of 2,4-Dichlorophenol in different physical states

IR Spectrum of 2,4-Dichlorophenol in different physical states

Gas chromatography with mass spectrometry detection (GC/MS) is the state-of-the-art method for the identification of unknown compounds. GC/MS, however, is not infallible and many compounds are difficult to identify with 100 % certainty. The problem with GC/MS is that it is a destructive method that tears apart a molecule. In infrared spectrometry (IR), molecular identification is based upon the IR absorptions of the whole molecule. This technique allows differentiation among isomers and yields information about functional groups and the position of such groups in a molecule. GC/IR complements the information obtained by GC/MS.

Interfaces

Initial attempts to couple GC with IR were made using high capacity GC columns and stopped flow techniques. As GC columns and IR technology advanced, the GC/IR method became more applicable. The advent of fused silica capillary GC columns and the availability of Fourier transform infrared spectrometry made GC/IR available commercially in several forms. GC/IR using a flow cell to capture the IR spectrum in real time is known as the “Light Pipe”. This is the most common form of GC/IR and the easiest to use. GC/IR can also be done by capturing or “trapping” the analytes of interest eluting from a GC and then measuring the IR spectrum. This can be done by cryogenically trapping the analyte in the solid phase. A third possibility is to trap the analyte in a matrix of inert material causing “Matrix Isolation” of the analyte followed by measuring the IR spectrum.

Infrared Spectroscopy

The physical state of the sample has a large effect upon the IR spectrum produced. Molecular interactions (especially hydrogen bonding) broadens absorption peaks. Solid and liquid samples produce IR spectra with broadened peaks that loses much of the potential information obtained in the spectra. Surrounding the sample molecule with gas molecules or in an inert matrix greatly sharpens the peaks in the spectrum, revealing more of the information and producing a “cleaner” spectrum. These spectra lend themselves better to computer searches of spectral libraries similar to the computer searching done in mass spectroscopy. IR spectral computer searching requires the standard spectra in the library be of the same physical state as the sample. So, a spectrum taken in a gaseous state should be searched against a library of spectra of standards in the gaseous state.

IR of various phases:

  • Liquid Phase – Molecular interactions broaden absorption peaks.
  • Solid Phase – Molecular interactions broaden absorption peaks.
  • Gas Phase – Lack of molecular interactions sharpen absorption peaks.
  • Matrix Isolation – Lack of molecular interactions sharpen absorption peaks.

IR Chromatograms

GC/IR yields chromatograms of infrared absorbance over time. These can be total infrared absorbance which is similar to the total ion chromatogram (TIC) in GC/MS or the infrared absorbance over a narrow band or bands analogous to selected ion chromatogram. This is a very powerful ability, because it gives the user the ability to focus on selected functional groups in a mixture of compounds.

Conclusion

Gas chromatography with infrared detection is a powerful tool for the elucidation of the structure of organic compounds in a mixture. It is complementary to GC/MS and is used to identify specific isomers and congeners of organic compounds. This method is greatly needed in the Cannabis industry to monitor the compounds that determine the flavor and the medicinal value of its products.


References

  1. GC–MS and GC–IR Analyses of the Methoxy-1-n-pentyl-3-(1-naphthoyl)-Indoles: Regioisomeric Designer Cannabinoids, Amber Thaxton-Weissenfluh, Tarek S. Belal, Jack DeRuiter, Forrest Smith, Younis Abiedalla, Logan Neel, Karim M. Abdel-Hay, and C. Randall Clark, Journal of Chromatographic Science, 56: 779-788, 2018
  2. Simultaneous Orthogonal Drug Detection Using Fully Integrated Gas Chromatography with Fourier Transform Infrared Detection and Mass Spectrometric Detection , Adam Lanzarotta, Travis Falconer, Heather McCauley, Lisa Lorenz, Douglas Albright, John Crowe, and JaCinta Batson, Applied Spectroscopy Vol. 71, 5, pp. 1050-1059, 2017
  3. High Resolution Gas Chromatography/Matrix Isolation Infrared Spectrometry, Gerald T. Reedy, Deon G. Ettinger, John F. Schneider, and Sid Bourne, Analytical Chemistry, 57: 1602-1609, 1985
  4. GC/Matrix Isolation/FTIR Applications: Analysis of PCBs, John F. Schneider, Gerald T. Reedy, and Deon G. Ettinger, Journal of Chromatographic Science, 23: 49-53, 1985
  5. A Comparison of GC/IR Interfaces: The Light Pipe Vs. Matrix Isolation, John F. Schneider, Jack C. Demirgian, and Joseph C. Stickler, Journal of Chromatographic Science, 24: 330- 335, 1986
  6. Gas Chromatography/Infrared Spectroscopy, Jean ‐ Luc Le Qu é r é , Encyclopedia of Analytical Chemistry, John Wiley & Sons, 2006