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Terpene_KAS2
From The Lab

The Other Side of Cannabis: Terpenes

By Dr. Zacariah Hildenbrand, Allegra Leghissa, Dr. Kevin A. Schug
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Terpene_KAS2

Have you ever wondered why all beers have that strong, characteristic smell? Or why you could tell the smell of cannabis apart from any other plant? The answer is simple – terpenes.

These 55,000 different molecules are responsible for a majority of the odors and fragrances around us, from a pine forest, to the air diffuser in your house 1–3. They all share the same precursor, isoprene, and because of that, they are all related and have similar molecular structures. Unfortunately, it is this uncanny similarity that makes their analysis so challenging; we still lack a complete list of which terpenes expected to be found in each given plant species 1,2.

Many different methods have been developed in an effort to provide a time-optimized and straightforward analysis. Gas chromatography (GC) is usually center stage due to the volatility of the terpenes. Therefore, there is significant concern with the type of GC detector used 2.

The flame ionization detector (FID) is a good quantitative detector for GC, but qualitatively it does not provide any information, except for retention time; the differentiation between terpene species is achieved solely by use of retention indices (RI), which are based on elution times from a particular GC stationary phase. The best part of the FID is its low cost, reliability, and relatively easy interface, which make it an effective tool for quality control (QC) but less so with respect to research and discovery 2.

The primary choice for a research setting is the mass spectrometer (MS) detector. It is more expensive and complicated than FID, but importantly, it provides both good quantitative capabilities, and it provides mass spectra for each species that elutes from the chromatograph. However, for terpene analysis, it may still not be the best detector choice. Since terpene class molecules share many structural and functional similarities, even their fragmentation and sub-sequential identification by MS may lead to inconsistent results, which need to be confirmed by use of RI. Still, MS is a better qualitative analysis tool than the FID, especially for distinguishing non-isobaric terpenes 2.

Recently, new technology based on vacuum ultraviolet spectroscopy (VUV) has been developed as a new GC detector. The VUV detector enables analysis of virtually all molecules; virtually all chemical compounds absorb light in the range in the 125-240 nm wavelength range probed by the detector, making it an essentially universal detector 4–11. Previously, spectroscopic absorption detectors for GC have lacked sufficient energy to measure absorption of most GC-amenable species. The VUV detector fills a niche, which is complementary to MS detection in terms of the qualitative information it provides.

Terpene_KAS2
Figure 1: A, Section of the chromatographic separation of a terpenes standard mix; B, highlight of the co-eluting terpenes, camphor and (-)-isopulegol; C, differences in the absorbance spectra of camphor and (-)-isopulegol.

With the VUV detector, each compound exhibits its own unique absorbance spectrum. Even isomers and isobars, which are prevalent in terpene mixtures and can be difficult to distinguish different species by their electron ionization mass spectra, can be well differentiated based on their VUV spectra 6,9,10.  Nevertheless, because analytes exhibit different spectra, it is not required to achieve a perfect chromatographic separation of the mixture components. Co-eluting peaks can be separated post-run through the use of library spectra and software inherent to the instrument 4,10. This ability is called “deconvolution”, and it is based on the fact that two co-eluting terpenes will give a peak with an absorbance spectrum equal to the sum of the two single absorbance spectra 4. Figure 1 shows the deconvolution process for two co-eluting terpenes, camphor and (-)-isopulegol. Due to their different absorbance spectra (Figure 1C), it is possible to fully separate the two peaks in post-run, obtaining sharp peaks for both analytes 6.

The deconvolution process has been shown to yield precise and accurate results. Thus, chromatographic resolution can be sacrificed in favor of spectroscopic resolution; this enables the development of methods with faster run times. With the ability to deconvolve unresolved peaks, a long temperature ramp to chromatographically separate all isomeric terpenes is not required 6. Additionally, the presence of coeluting components, which might normally go undetected with some GC detectors, can be easily judged based on comparison of the measured spectra with pure reference spectra contained in the VUV spectral library.

The other issue in terpenes analysis is the extraction process. Terpenes can be extracted with the use of solvents (e.g., methanol, ethanol, hexane, and cyclohexane, among others), but the process is usually time-consuming, costly and not so environmentally-friendly 2. The plant needs to be manually crushed and then aliquots of solvent are used to extract components from the plant, ideally at least 3 times and combined to achieve acceptable results. The problem is that some terpenes may respond better to a certain solvent, making their extraction easier and more optimized than for others 2. The choice of solvent can cause discrimination against the extraction some terpenes, which limits the comprehensiveness of analysis.

Headspace is another technique that can be used for the sample preparation of terpenes. Headspace sampling is based on heating the solid or liquid sample inside a sealed vial, and then analyzing the air above it after sufficient equilibration. In this way, only volatile analytes are extracted from the solid/liquid sample into the gas phase; this allows relatively interference-free sampling 12–14.

How do we know whether our extraction analysis methods are correct and comprehensive for a certain plant sample? Unfortunately, there is not a complete list of available molecules for each plant species, and even if two specimens may smell really similar to our nose, their terpenes profiles may be notably different. When working with a new plant material, it is difficult to predict the extraction efficiency for the vast array of terpenes that may be present. We can only perform it with different extraction and detection methods, and compare the results.

The route for a comprehensive and fast analysis of terpenes is therefore still long; however, their intoxicating aromas and inherent medicinal value has provided a growing impetus for researchers around the world. Considering the evolving importance of Cannabis and the growing body of evidence on the synergistic effects between terpenes and cannabinoids, it is likely that newly improved extraction and analysis methods will be developed, paving the way for a more complete list of terpene species that can be found in different cultivars. The use of new analytical technologies, such as the VUV detector for GC, should aid considerably in this endeavor.


References:

[1]          Breitmaier E., Terpenes: Flavors, Fragrances, Pharmaca, Pheromones. John Wiley & Sons 2006.

[2]          Leghissa A., Hildenbrand Z. L., Schug K. A., A Review of Methods for the Chemical Characterization of Cannabis Natural Products. J. Sep. Sci.2018, 41, 398–415 .

[3]          Benvenuto E., Misra B. B., Stehle F., Andre C. M., Hausman J.-F., Guerriero G., Cannabis sativa: The Plant of the Thousand and One Molecules. Front. Plant Sci2016, 719, DOI: 10.3389/fpls.2016.00019.

[4]          Schug K. A., Sawicki I., Carlton D. D., Fan H.,Mcnair H. M.,Nimmo J. P., Kroll P.,Smuts J.,Walsh P., Harrison D., Vacuum Ultraviolet Detector for Gas Chromatography. Anal. Chem.2014, 86, 8329–8335 .

[5]          Fan H.,Smuts J., Walsh P.,Harrison D., Schug K. A., Gas chromatography-vacuum ultraviolet spectroscopy for multiclass pesticide identification. J. Chromatogr. A2015, DOI: 10.1016/j.chroma.2015.02.035.

[6]          Qiu C.,Smuts J., Schug K. A., Analysis of terpenes and turpentines using gas chromatography with vacuum ultraviolet detection. J. Sep. Sci.2017, 40, 869–877 .

[7]          Leghissa A., Smuts J., Qiu C., Hildenbrand Z. L., Schug K. A., Detection of cannabinoids and cannabinoid metabolites using gas chromatography-vacuum ultraviolet spectroscopy. Sep. Sci. Plus2018, 1.

[8]          Bai L.,Smuts J., Walsh P., Fan H., Hildenbrand Z., Wong D., Wetz D., Schug K. A., Permanent gas analysis using gas chromatography with vacuum ultraviolet detection. J. Chromatogr. A2015,1388, 244–250 .

[9]          Skultety L., Frycak P., Qiu C.,Smuts J., Shear-Laude L., Lemr K., Mao J. X., Kroll P., Schug K. A., Szewczak A., Vaught C., Lurie I., Havlicek V., Resolution of isomeric new designer stimulants using gas chromatography – Vacuum ultraviolet spectroscopy and theoretical computations. Anal. Chim. Acta2017, 971, 55–67 .

[10]       Bai L., Smuts J., Walsh P., Qiu C., McNair H. M., Schug K. ., Pseudo-absolute quantitative analysis using gas chromatography–vacuum ultraviolet spectroscopy–a tutorial. Anal. Chim. Acta2017, 953, 10–22 .

[11]       Schenk J., Nagy G., Pohl N. L. B., Leghissa A., Smuts J., Schug K. A., Identification and deconvolution of carbohydrates with gas chromatography-vacuum ultraviolet spectroscopy. J. Chromatogr. A2017, 1513, 210–221 .

[12]       Van Opstaele F., De Causmaecker B., Aerts G., De Cooman L., Characterization of novel varietal floral hop aromas by headspace solid phase microextraction and gas chromatography-mass spectrometry/olfactometry. J. Agric. Food Chem.2012, 60, 12270−12281 .

[13]       Hamm S., Bleton J., Connan J., Tchapla A., A chemical investigation by headspace SPME and GC-MS of volatile and semi-volatile terpenes in various olibanum samples. Phytochemistry2005,66, 1499–1514 .

[14]       Aberl A., Coelhan M., Determination of volatile compounds in different hop Varieties by headspace-trap GC/MS-in comparison with conventional hop essential oil analysis. J. Agric. Food Chem.2012, 60, 2785−2792 .

Cannabis Regulation Update, Terpene & Residual Solvent Analysis and Heavy Metals Analysis

This free webinar, hosted by Perkin Elmer and CIJ, will dive into the regulatory environments surrounding cannabis testing, as well as terpene, residual solvent and heavy metals testing. Are you finding it difficult to keep up with changing regulations for the cannbis industry? Are you looking to reduce hands-on analysis time? Speed up sample processing? Have less waste? Possibly reduce the number of individual tests running in your laboratory?
Learning Objectives:
• Understand and prepare for new state regulations in the US and pending federal regulations for Canada
• Learn how to run two regulated tests (terpenes and residual solvents) in one analysis, on one instrument, and with one SOP
• Overcome challenging cannabis matrices for heavy metal analysis with microwave digestion

Sign up for free today!

A2LA Accredits First Cannabis Lab in PA

By Aaron G. Biros
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According to a press release sent out this morning, the American Association for Laboratory Accreditation (A2LA) accredited their first Pennsylvania cannabis-testing laboratory. Located in Harrisburg, PA, Keystone State Testing finalized their accreditation for ISO/IEC 17025 on February 21, 2018.

KeystoneStateTestinglogoA2LA also accredited the laboratory to two cannabis-testing-specific programs, ISO/IEC 17025 – General Requirements for the Competence of Testing and Calibration Laboratories and A2LA R243 – Specific Requirements – Cannabis Testing Laboratory Accreditation Program. The R243 program is a collaboration with Americans for Safe Access (ASA) that takes some recommendation for regulators from the American Herbal Products Association (AHPA).

KellyGreenland
Dr. Kelly Greenland, owner and operator of Keystone State Testing

Keystone State Testing is now able to perform all of the tests for cannabis products under the state of Pennsylvania’s regulations. According to Dr. Kelly Greenland, owner and operator of Keystone State Testing, getting accredited is about safeguarding patient safety. “Keystone State Testing is proud to be the first Pennsylvania laboratory to earn A2LA ISO/IEC 17025 accreditation as well as ASA’s Patient Focused Certification,” says Dr. Greenland. “We regard these accreditations and certifications as the first steps in ensuring patient safety and will continue to do everything within our power to ensure medical marijuana patient safety.”

A2LA General Manager Adam Gouker says he wants to see more accreditations include the ASA requirements in R243. “A2LA is pleased to see the growing adoption of the combined assessment to include the ASA requirements,” says Gouker. “Our staff has worked tirelessly in conjunction with ASA staff to create this combined program and offer something that no other accreditation body in the world offers. We congratulate Keystone State Testing Labs on leading the charge in the state of Pennsylvania and laying the groundwork for future laboratories to follow.”

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From The Lab

The Case for ISO/IEC 17025 Accreditation in Cannabis Testing Laboratories

By Amy Ankrum
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Government regulations keep millions of Americans safe every year by controlling what companies can put in their products and the standards those products must meet to be sold to consumers.

Enter the strange case of legal cannabis: In order for cannabis to be legally distributed by licensed medical professionals and businesses, it must be tested. But unlike other consumable goods, cannabis is not regulated by the FDA. Without an overarching federal policy requiring cannabis testing laboratory accreditation, the testing and laboratory requirements differ greatly across state lines.For medical cannabis specifically, accredited testing facilities are especially important. 

To be federally regulated, cannabis would first have to be federally legalized. It turns out that states and businesses alike are not willing to wait for a federal mandate. Many states have begun to adopt standards for cannabis testing and some, such as Ohio, have even announced mandatory ISO/IEC 17025 accreditation for all cannabis testing laboratories. As the industry evolves, increased compliance expectations are certain to evolve in tandem.

Some cannabis labs have even taken the initiative to seek ISO/IEC 17025 accreditation of their own volition. Seth Wong, President of TEQ Analytics Laboratories, shared in a press release:

“By achieving ISO/IEC 17025 accreditation, TEQ Analytical Labs believes that we can address the concerns throughout the cannabis industry regarding insufficient and unreliable scientific analysis by providing our clients with State required tests that are accredited by an international standard.”

Other laboratories, such as DB Labs in Las Vegas and EVIO Labs in Florida are also leading the accreditation charge in their respective states, ahead of any state mandates.

There are key reasons why accreditation in cannabis testing labs is important. First and foremost, cannabis is a consumable product. Like fruits and vegetables, cannabis is prone to pesticides, fungi and contaminants. The result of putting a potentially hazardous material on the market without proper and documented testing could lead to a public health crisis. An accredited testing lab, however, will ensure that the cannabis products they test are free from harmful contaminants.

By utilizing role-based trainings, labs can trust employees are receiving proper onboarding.

For medical cannabis specifically, accredited testing facilities are especially important. Because many consumers of medical cannabis are immuno-compromised (such as in the case of chemotherapy patients), ensuring that products are free from any and all contaminants is critical. Further, in order to accurately determine both short- and long-term effects of prescribed cannabis consumption, accredited and compliant laboratories are necessary.

Accreditation standards like ISO/IEC 17025 also provide confidence that testing is performed properly and to an internationally accepted standard. Rather than returning a “pass/fail” rating on products, the Cannabis Safety Institute reports that an ISO/IEC 17025 laboratory is required to produce numerical accuracy percentages in testing for “at a minimum, cannabinoids, pesticides, microbiology, residual solvents, and water activity.” Reliable data sets that can be reviewed by both accreditors and the public foster trust between producers and consumers.

Finally, ISO/IEC 17025 accreditation demonstrates that a laboratory is properly staffed and trained. The Cannabis Safety Institute’s “Standards for Cannabis Testing Laboratories” explains that conducting proper analytical chemistry on cannabinoids (the chemical compounds extracted from cannabis that alter the brain’s neurotransmitter release) requires personnel who have met specific academic and training credentials. A system to monitor, manage and demonstrate proficiency is necessary to achieve and maintain accreditation. With electronic systems in place, this management and documentation minimizes risk and also minimizes administrative time tracking and maintaining training records.

Following the proper steps of a standardized process is key to improving and growing the cannabis industry in coming yearsFor cannabis testing labs, utilizing a comprehensive software solution to achieve and maintain compliance to standards such as ISO/IEC 17025 is key. Absent of a software solution, the necessary compliance requirements can become a significant burden to the organization. Paper tracking systems and complex spreadsheets open up organizations to the likelihood of errors and ultimately risk.

Because ISO/IEC 17025 has clearly defined expectations for training, a software solution also streamlines the training process while simultaneously documenting proficiency. By utilizing role-based trainings, organizations can be confident employees are receiving proper onboarding and in-service training. Additionally, the effectiveness of training can be proven with reports, which results in smoother audits and assessments.

Following the proper steps of a standardized process is key to improving and growing the cannabis industry in coming years- which means utilizing technology tools such as electronic workflows to ensure proper process controls. Beyond adding critical visibility, workflows also create efficiencies that can eliminate the need to increase staffing as companies expand and grow.

For an industry that is changing at a rapid pace, ensuring traceability, efficient processes and visibility across organizations is paramount. Using a system that enables automation, process control, document management and documented training procedures is a step in the right direction. With the proper software tools in place, cannabis testing labs can achieve compliance goals, demonstrate reliable and relevant results and most importantly ensure consumer safety.

VinceSebald

Maintenance and Calibration: Your Customers Are Worth It!

By Vince Sebald
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Ultimately, the goal of any good company is to take care of their customers by providing a quality product at a competitive price. You take the time to use good practices in sourcing raw materials, processing, testing and packaging to make sure you have a great final product. Yet in practice, sometimes the product can degrade over time, or you find yourself facing costly manufacturing stoppages and repairs due to downed equipment or instrumentation. This can harm your company’s reputation and result in real, negative effects on your bottom line.

One thing you can do to prevent this problem is to have a properly scaled calibration and maintenance program for your organization.

First, a short discussion of terms:

Balance Calibration
Figure 1– Periodic calibration of an electronic balance performed using traceable standard weights helps to ensure that the balance remains within acceptable operating ranges during use and helps identify problems.

Calibration, in the context of this article, refers to the comparison of the unit under test (your equipment) to a standard value that is known to be accurate. Equipment readings often drift over time due to various reasons and may also be affected by damage to the equipment. Periodic calibration allows the user to determine if the unit under test (UUT) is sufficiently accurate to continue using it. In some cases, the UUT may require adjustment or may not be adjustable and should no longer be used.

Maintenance, in the context of this article, refers to work performed to maximize the performance of equipment and support a long life span for the equipment. This may include lubrication, adjustments, replacement of worn parts, etc. This is intended to extend the usable life of the equipment and the consistency of the quality of the work performed by the equipment.

There are several elements to putting together such a program that can help you to direct your resources where they will have the greatest benefit. The following are some key ingredients for a solid program:

Keep it Simple: The key is to scale it to your operation. Focus on the most important items if resources are strained. A simple program that is followed and that you can defend is much better than a program where you can never catch up.

Written Program: Your calibration and maintenance programs should be written and they should be approved by quality assurance (QA). Any program should include the following: 

  • Equipment Assessment and Identification: Assess each piece of equipment or instrument to determine if it is important enough to be calibrated and/or requires maintenance. You will probably find much of your instrumentation is not used for a critical purpose and can be designated as non-calibrated. Each item should have an ID assigned to allow tracking of the maintenance and/or calibration status.
  • Scheduling System: There needs to be some way to schedule when equipment is due for calibration or maintenance. This way it is easy to stay on top of it. A good scheduling system will pay for itself over time and be easy to use and maintain. A web-based system is a good choice for small to mid-sized companies.
  • Calibration Tolerance Assignment: If you decide to calibrate an instrument, consider what kind of accuracy you actually need from the equipment/instrument. This is a separate discussion on its own, but common rule of thumb is that the instrument should be at least 4 times more accurate than your specification. For very important instruments, it may require spending the money to get a better device.
  • Calibration and Maintenance Interval Assignments: Consider what interval you are going to perform maintenance for each equipment item. Manufacturer recommendations are based on certain conditions. If you use the equipment more or less often than “normal” use, consider adjusting the interval between calibrations or maintenance. 
  • OOT Management: If you do get an Out of Tolerance (OOT) result during a calibration and you find that the instrument isn’t as accurate as you need. Congratulations! You just kept it from getting worse. Review the history and see if this may have had an effect since the last passing calibration, adjust or replace the instrument, take any other necessary corrective actions, and keep it up.

    Maintenance with Checklist
    Figure 2- Maintenance engineers help keep your systems running smoothly and within specification for a long, trouble-free life.
  • Training: Make sure personnel that use the equipment are trained on its use and not to use equipment that is not calibrated for critical measurements. Also, anyone performing calibration and/or maintenance should be qualified to do so. It is best to put a program in place as soon as you start acquiring significant equipment so that you can keep things running smoothly, avoid costly repairs and quality control problems. Don’t fall into the trap of assuming equipment will keep running just because it has run flawlessly for months or years. There are many bad results that can come of mismanaged calibration and/or maintenance including the following:
  • Unscheduled Downtime/Damage/Repairs: A critical piece of equipment goes down. Production stops, and you are forced to schedule repairs as soon as possible. You pay premium prices for parts and labor, because it is an urgent need. Some parts may have long lead times, or not be available. You may suffer reputational costs with customers waiting for delivery. Some calibration issues could potentially affect operator safety as well.
  • Out of Specification Product: Quality control may indicate that product is not maintaining its historically high quality. If you have no calibration and maintenance program in place, tracking down the problem is even more difficult because you don’t have confidence in the readings that may be indicating that there is a problem.
  • Root Cause Analysis: Suppose you find product that is out of specification and you are trying to determine the cause. If there is no calibration and maintenance program in place, it is far more difficult to pinpoint changes that may have affected your production system. This can cause a very significant impact on your ability to correct the problem and regain your historical quality standards of production.

A solid calibration and maintenance program can go a long way to keeping your production lines and quality testing “boring”, without any surprises or suspense, and can allow you to put more sophisticated quality control systems in place. Alternatively, an inappropriate system can bog you down with paperwork, delays, unpredictable performance, and a host of other problems. Take care of your equipment and relax, knowing your customers will be happy with the consistent quality that they have become accustomed to.

Swetha Kaul, PhD

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

By Swetha Kaul, PhD
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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
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:

  1. 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.
  2. 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.

 

dSPE cleanups

The Grass Isn’t Always Greener: Removal of Purple Pigmentation from Cannabis

By Danielle Mackowsky
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dSPE cleanups
strains
Cannabis strains used (clockwise from top left): Agent Orange, Tahoe OG, Blue Skunk, Grand Daddy and Grape Drink

Cannabis-testing laboratories have the challenge of removing a variety of unwanted matrix components from plant material prior to running extracts on their LC-MS/MS or GC-MS. The complexity of the cannabis plant presents additional analytical challenges that do not need to be accounted for in other agricultural products. Up to a third of the overall mass of cannabis seed, half of usable flower and nearly all extracts can be contributed to essential oils such as terpenes, flavonoids and actual cannabinoid content1. The biodiversity of this plant is exhibited in the over 2,000 unique strains that have been identified, each with their own pigmentation, cannabinoid profile and overall suggested medicinal use2. While novel methods have been developed for the removal of chlorophyll, few, if any, sample preparation methods have been devoted to removal of other colored pigments from cannabis.

QuEChERS
Cannabis samples following QuEChERS extraction

Sample Preparation

Cannabis samples from four strains of plant (Purple Drink, Tahoe OG, Grand Daddy and Agent Orange) were hydrated using deionized water. Following the addition of 10 mL acetonitrile, samples were homogenized using a SPEX Geno/Grinder and stainless steel grinding balls. QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) non-buffered extraction salts were then added and samples were shaken. Following centrifugation, an aliquot of the supernatant was transferred to various blends of dispersive SPE (dSPE) salts packed into centrifugation tubes. All dSPE tubes were vortexed prior to being centrifuged. Resulting supernatant was transferred to clear auto sampler vials for visual analysis. Recoveries of 48 pesticides and four mycotoxins were determined for the two dSPE blends that provided the most pigmentation removal.

Seven dSPE blends were evaluated for their ability to remove both chlorophyll and purple pigmentation from cannabis plant material:

  • 150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg Chlorofiltr®
  • 150 mg MgSO4, 50 mg C18, 50 mg Chlorofiltr®
  • 150 mg MgSO4, 50 mg PSA
  • 150 mg MgSO4, 25 mg C18
  • 150 mg MgSO4, 50 mg PSA, 50 mg C18
  • 150 mg MgSO4, 25 mg PSA, 7.5 mg GCB
  • 150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg GCB

Based on the coloration of the resulting extracts, blends A, F and G were determined to be the most effective in removing both chlorophyll (all cannabis strains) and purple pigments (Purple Drink and Grand Daddy). Previous research regarding the ability of large quantities of GCB to retain planar pesticides allowed for the exclusion of blend G from further analyte quantitation3. The recoveries of the 48 selected pesticides and four mycotoxins for blends A and F were determined.

dSPE cleanups
Grand Daddy following various dSPE cleanups

Summary

A blend of MgSO4, C18, PSA and Chlorofiltr® allowed for the most sample clean up, without loss of pesticides and mycotoxins, for all cannabis samples tested. Average recovery of the 47 pesticides and five mycotoxins using the selected dSPE blend was 75.6% were as the average recovery when including GCB instead of Chlorofiltr® was 67.6%. Regardless of the sample’s original pigmentation, this blend successfully removed both chlorophyll and purple hues from all strains tested. The other six dSPE blends evaluated were unable to provide the sample clean up needed or had previously demonstrated to be detrimental to the recovery of pesticides routinely analyzed in cannabis.


References

(1)           Recommended methods for the identification and analysis of cannabis and cannabis products, United Nations Office of Drugs and Crime (2009)

(2)            W. Ross, Newsweek, (2016)

(3)            Koesukwiwat, Urairat, et al. “High Throughput Analysis of 150 Pesticides in Fruits and Vegetables Using QuEChERS and Low-Pressure Gas Chromatography Time-of-Flight Mass Spectrometry.” Journal of Chromatography A, vol. 1217, no. 43, 2010, pp. 6692–6703., doi:10.1016/j.chroma.2010.05.012.

Nevada Testing Lab Licenses Suspended, Then Reinstated

By Aaron G. Biros
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When Nevada legalized adult use sales this past summer, the market exploded and undoubtedly flooded licensed testing labs with samples to get products on shelves. In August, roughly a month after the start of adult use sales, a Las Vegas cannabis-testing lab, G3 Labs, had their license suspended for an unknown compliance issue.

“We can’t disclose the details of the suspension, including anything about penalties,” said Klapstein. “Under NRS 360.255, the information is confidential.”Then in late December, the Nevada Department of Taxation, one of the bodies tasked with regulating the state’s industry, announced in an email they suspended two more cannabis testing lab licenses. Certified Ag Lab in Sparks, Nevada and Cannex Nevada, LLC, in Las Vegas (also known as RSR Analytical Laboratories) both had their licenses suspended on December 22 and December 26 respectively.

Stephanie Klapstein, spokeswoman for the Department of Taxation, told the Reno Gazette Journal that both of those labs were not following proper protocols. “During separate, routine inspections, Department inspectors discovered that these two labs were not following proper lab procedures and good laboratory practices,” says Klapstein. “Their licenses were suspended until those deficiencies were corrected.”

According to the Reno Gazette Journal, both of those labs had their licenses reinstated and have since resumed normal business. During their license suspension, the labs were not allowed to operate and the department directed licensed cannabis businesses to submit samples to other labs. The department also directed the suspended labs in the email to coordinate with their clients who had samples in for testing; to either have their samples transferred to a different lab or a new sample taken for another lab to test. They did note that no product recalls were deemed necessary because of the suspension.

In that same email, the department directed licensed cannabis businesses to state-licensed labs in good standing, including 374 Labs, ACE Analytical Laboratory, DB Labs, Digipath Labs, MM Lab and NV CANN Lab. But on the department’s website, it says there are 11 licensed testing labs.

Back in September when we reported on the first lab license suspension, Klapstein told CIJ that under state law they couldn’t discuss any reasons behind why they suspended licenses. “We can’t disclose the details of the suspension, including anything about penalties,” said Klapstein. “Under NRS 360.255, the information is confidential.”

Because of that confidentiality, there are a number of questions left unanswered: With three lab licenses suspended in the first six months of the Nevada’s adult use market being open, how are testing labs keeping up with the market’s pace? What did those suspended labs do wrong? Do the regulations adequately protect public health and safety?

amandarigdon

Proficiency Testing in the Cannabis Industry: An Inside Look

By Cannabis Industry Journal Staff
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amandarigdon

Cannabis Labs Virtual Conference: Part 4

Proficiency Testing in the Cannabis Industry: An Inside Look
By Amanda Rigdon, Chief Technical Officer, Emerald Scientific

This presentation covers specifics of different proficiency testing schemes available to the cannabis industry. Additionally, specific challenges facing both laboratories and PT providers in the cannabis industry will be addressed. Data relating to residual solvent and potency proficiency testing will be presented.

Integrating Your LIMS System With State Tracking Systems

By Cannabis Industry Journal Staff
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Cannabis Labs Virtual Conference: Part 3

Integrating Your LIMS System With State Tracking Systems
By Hannah O’Brien, Operations Manager, Confident Cannabis

Running a lab is hard. Running a cannabis lab is harder. Watch this webinar hosted by Confident Cannabis, the most popular and only free cannabis LIMS in the country, to learn how cannabis compliance and regulatory burdens impact analytical testing laboratories in any state, and how important purpose-built software solutions are to make their business run smoothly.