Tag Archives: validate

Multi-Element Analysis Using ICP-MS: A Look at Heavy Metals Testing

By Cannabis Industry Journal Staff
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Across the country and across the world, governments that legalize cannabis implement increasingly rigorous requirements for laboratory testing. Helping to protect patients and consumers from contaminants, these requirements involve a slew of lab tests, including quantifying the levels of microbial contaminants, pathogens, mold and heavy metals.

Cannabis and hemp have a unique ability to accumulate elements found in soil, which is why these plants can be used as effective tools for bioremediation. Because cannabis plants have the ability to absorb potentially toxic and dangerous elements found in the soil they grow in, lab testing regulations often include the requirement for heavy metals testing, such as Cadmium, Lead, Mercury, Arsenic and others.

In addition to legal cannabis markets across the country, the USDA announced the establishment of the U.S. Domestic Hemp Production Program, following the enactment of the 2018 Farm Bill, essentially legalizing hemp. This announcement comes with information for hemp testing labs, including testing and sampling guidelines. While the information available on the USDA’s website only touches on testing for THC, required to be no greater than 0.3% dry weight concentration, more testing guidelines in the future are sure to include a discussion of heavy metals testing.

Table 1. ICP-MS operating conditions (shaded parameters were automatically optimized during start up for the HMI conditions).

In an application note produced by Agilent Technologies, Inc., the Agilent 7800 ICP-MS was used to analyze 25 elements in a variety of cannabis and hemp-derived products. The study was conducted using that Agilent 7800 ICP-MS, which includes Agilent’s proprietary High Matrix Introduction (HMI) system. The analysis was automated  by using the Agilent SPS 4 autosampler.

Instrumentation

The instrument operating conditions can be found in Table 1. In this study, the HMI dilution factor was 4x and the analytes were all acquired in the Helium collision mode. Using this methodology, the Helium collision mode consistently reduces or completely eliminates all common polyatomic interferences using kinetic energy discrimination (KED).

Table 2. Parameters for microwave digestion.

As a comparison, Arsenic and Selenium were also acquired via the MassHunter Software using half-mass correction, which corrects for overlaps due to doubly charged rare earth elements. This software also collects semiquantitative or screening data across the entire mass region, called Quick Scan, showing data for elements that may not be present in the original calibration standards.

SRMs and Samples

Standard reference materials (SRMs) analyzed from the National Institute of Standards and Technology (NIST) were used to verify the sample prep digestion process. Those included NIST 1547 Peach Leaves, NIST 1573a Tomato Leaves and NIST 1575 Pine Needles. NIST 1640a Natural Water was also used to verify the calibration.

Figure 1. Calibration curves for As, Cd, Pb, and Hg.

Samples used in the study include cannabis flower, cannabis tablets, a cannabidiol (CBD) tincture, chewable candies and hemp-derived cream.

Sample Preparation

Calibration standards were prepared using a mix of 1% HNO3 and 0.5% HCl. Sodium, Magnesium, Potassium, Calcium and Iron were calibrated from 0.5 to 10 ppm. Mercury was calibrated from 0.05 to 2 ppb. All the other elements were calibrated from 0.5 to 100 ppb.

Table 3. Calibration summary data acquired in He mode. Data for As and Se in shaded cells was obtained using half mass correction tuning.

After weighing the samples (roughly 0.15 g of cannabis plant and between 0.3 to 0.5 g of cannabis product) into quartz vessels, 4 mL HNO3 and 1 mL HCl were added and the samples were microwave digested using the program found in Table 2.

HCI was included to ensure the stability of Mercury and Silver in solution. They diluted the digested samples in the same acid mix as the standards. SRMs were prepared using the same method to verify sample digestion and to confirm the recovery of analytes.

Four samples were prepared in triplicate and fortified with the Agilent Environmental Mix Spike solution prior to the analysis. All samples, spikes and SRMs were diluted 5x before testing to reduce the acid concentration.

Calibration

Table 4. ICV and CCV recovery tests. Data for As and Se in shaded cells was obtained using half mass correction tuning.

The calibration curves for Arsenic, Cadmium, Lead and Mercury can be found in Figure 1 and a summary of the calibration data is in Table 3. For quality control, the SRM NIST 1645a Natural Water was used for the initial calibration verification standard.  Recoveries found in Table 4 are for all the certified elements present in SRM NIST 1640a. The mean recoveries and concentration range can also be found in Table 4. All the continuing calibration solution recoveries were within 10% of the expected value.

Internal Standard Stability

Figure 2 highlights the ISTD signal stability for the sequence of 58 samples analyzed over roughly four hours. The recoveries for all samples were well within 20 % of the value in the initial calibration standard.

Figure 2. Internal standard signal stability for the sequence of 58 samples analyzed over ~four hours.

Results

In Table 5, you’ll find that three SRMs were tested to verify the digestion process. The mean results for most elements agreed with the certified concentrations, however the results for Arsenic in NIST 1547 and Selenium in both NIST 1547 and 1573a did not show good agreement due to interreferences formed from the presence of doubly-charged ions

Table 5. Mean concentrations (ppm) of three repeat measurements of three SRMs, including certified element concentrations, where appropriate, and % recovery.

Some plant materials can contain high levels of rare earth elements, which have low second ionization potentials, so they tend to form doubly-charged ions. As the quadrupole Mass Spec separates ions based on their mass-to-charge ratio, the doubly-charged ions appear at half of their true mass. Because of that, a handful of those doubly-charged ions caused overlaps leading to bias in the results for Arsenic and Selenium in samples that have high levels of rare earth elements. Using half mass correction, the ICP-MS corrects for these interferences, which can be automatically set up in the MassHunter software. The shaded cells in Table 5 highlight the half mass corrected results for Arsenic and Selenium, demonstrating recoveries in agreement with the certified concentrations.

In Table 6, you’ll find the quantitative results for cannabis tablets and the CBD tincture. Although the concentrations of Arsenic, Cadmium, Lead and Cobalt are well below current regulations’ maximum levels, they do show up relatively high in the cannabis tablets sample. Both Lead and Cadmium also had notably higher levels in the CBD tincture as well.

Table 6. Quantitative data for two cannabis-related products and two cannabis samples plus mean spike recovery results. All units ppb apart from major elements, which are reported as ppm.

A spike recovery test was utilized to check the accuracy of the method for sample analysis. The spike results are in Table 6.

Using the 7800 ICP-MS instrument and the High Matrix Introduction system, labs can routinely analyze samples that contain high and very variable matrix levels. Using the automated HMI system, labs can reduce the need to manually handle samples, which can reduce the potential for contamination during sample prep. The MassHunter Quick Scan function shows a complete analysis of the heavy metals in the sample, including data reported for elements not included in the calibration standards.

The half mass correction for Arsenic and Selenium allows a lab to accurately determine the correct concentrations. The study showed the validity of the microwave sample prep method with good recovery results for the SRMs. Using the Agilent 7800 ICP-MS in a cannabis or hemp testing lab can be an effective and efficient way to test cannabis products for heavy metals. This test can be used in various stages of the supply chain as a tool for quality controls in the cannabis and hemp markets.


Disclaimer: Agilent products and solutions are intended to be used for cannabis quality control and safety testing in laboratories where such use is permitted under state/country law.

Food Safety Hazards for the Cannabis Industry: ERP Can Help

By Daniel Erickson
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To say that there has been explosive growth in the cannabis edibles market is an understatement. In the next 5 years, edibles are expected to become a $5.3 billion industry according to the Brightfield Group, a cannabis market research firm. Skyrocketing demand for cannabis infusion in food and beverage products, both recreational and medical, has prompted concern for the health and safety of consumers due to the lack of federal legality and regulatory guidelines for these products. Edibles consumers assume the same level of safety and quality present in other food and beverage products in the market. Progressive cannabis operations are opting to follow current food safety guidelines to mitigate hazards despite not being legally required to do so. Utilizing these guidelines, as well as incorporating an industry-specific ERP solution to automate processes, enables cannabis businesses to provide quality, consistent products and establish standards to support the eventuality of federal cannabis legalization.

FDAlogoEdibles consumption has grown not only in a recreational capacity but also for medicinal use to treat chronic pain, relieve epilepsy symptoms, decrease nausea, combat anxiety and other health issues. Cannabidiol (CBD) infused products take many forms including candies, baked goods, chocolate, oils, sprays, beer, soda, tea and coffee. Their popularity is partly due to their more socially acceptable use, creating an appeal to a wider audience. While the Food and Drug Administration (FDA) is responsible for overseeing food and beverage safety for products sold in the United States, their regulations are not enforced in the cannabis-infused marketplace. Without federal regulatory standards, there exist inherent food safety concerns that create risks to consumers. The average cannabis edibles customer is likely unaware of the “consume at your own risk” nature of the products.

The structure of cannabidiol (CBD), one of 400 active compounds found in cannabis.

There are many consequences of not addressing food safety hazards, as the possibility of food-borne illnesses resulting from unsafe and unsanitary manufacturing facilities have become increasingly likely in an unregulated market. In addition to these concerns, problems particular to cannabis growing and harvesting practices are also possible. Aflatoxins (mold carcinogens) on the cannabis bud, pesticide residue on plants, pest contamination, improper employee handling and training and inaccurate levels of CBD all contribute to the risk of outbreaks, hefty fines, recalls or business closure. To mitigate the risk of exposure, it is recommended that edible manufacturers employ a proactive approach of observing proper food safety standards that encompass the growing, manufacturing, packaging, handling, storing and selling of products. With a focus on safety, cannabis edible manufacturers utilizing an ERP solution and vendor with experience in food safety management will reap the benefits that food and beverage businesses have experienced for decades.

Following established food safety protocols and guidelines of the food and beverage and dietary supplement industry, allows manufacturers of cannabis-infused edibles to implement a proactive approach by focusing on safety and reducing the risk to their operations. Food and beverage manufacturing best practices include: maintaining supplier list, quality control testing, sanitary handling of consumables, maintaining clean facilities and mitigating cross-contamination. Successful food and beverage manufacturers also incorporate a food safety team, preventative controls, and a food safety plan (FSP) including a detailed recall plan into their safety initiatives.HACCP

Establishing and maintaining a supplier list with approved quality ingredients is an essential building block for reducing food safety hazards and can be easily maintained within an ERP. Documentation of vendor information and recording of stringent testing results ensures that specific quality standards are met. Conducting extensive research regarding the source of the ingredients for use in cannabis edibles allows companies to confirm that raw ingredients were processed in a safe environment. The importance of supply chain visibility cannot be understated, as suppliers are in control of potential hazards. Quality processes and regularly performed testing is automated through the workflow of an ERP solution in the manufacturing facility – enabling noncompliant raw materials to be quarantined and removed from production. The ERP solution allows for management of critical control points to catch non-compliance issues and set-up of alternate suppliers in case of supplier-related issues. Maintaining approved supplier lists is an industry best practice that provides current and accurate information in the event of possible consumer adverse reactions.

GMPFollowing current Good Manufacturing Practices (cGMPs) should underlie efforts to address food safety concerns in the cannabis edibles industry. An ERP solution assists with documenting these quality initiatives to ensure the safe and sanitary manufacturing, storage and packaging of food for human consumption. This includes evaluating equipment status, establishing cleaning and sanitation procedures and eliminating allergen cross-contamination. Employee training is conducted and documentation maintained in the ERP solution to ensure hygienic procedures, allergen awareness, illness reporting and required food or cannabis handling certifications.

Cannabis businesses can benefit from establishing a food safety team tasked with developing a Hazard Analysis Critical Control Points (HACCP) plan to provide effective procedures and protect consumers from the hazards inherent in edible cannabis products – including biological, chemical and physical dangers. Automating processes within an ERP solution prevents and controls hazards before food safety is compromised. Since HACCP plans have historically been used by food and beverage manufacturers to ensure a safe product for the consumer, cannabis edibles manufacturers can apply the lessons from these food safety protocols and procedures in their initiatives.By utilizing food safety best practices partnered with an ERP solution, cannabis businesses can avoid the negative consequences resulting from failure to address food safety hazards in manufacturing, storage and packaging. 

A comprehensive FSP, as required by the FDA’s Food Safety Modernization Act (FSMA), identifies food safety hazards and guides the development of a company-specific, validated plan. This plan documents processes throughout the manufacturing, processing, packaging and storage stages of the operation. ERP software provides real-time, forward and backward lot traceability from seed-to-sale with the ability to track materials, document recipes and accurately label products. This detailed level of traceability provides an automated system that implements and documents food safety policies throughout the manufacturing process. With a trained Preventative Control Qualified Individual (PCQI) implementing the FSP, preventative controls, recall plans and employee training records are maintained in an integrated system.

The cannabis market’s tremendous growth has driven edibles manufacturers to follow the same guidelines as mainstream food and beverage companies to ensure safety is afforded equally to consumers of cannabis edibles. By utilizing food safety best practices partnered with an ERP solution, cannabis businesses can avoid the negative consequences resulting from failure to address food safety hazards in manufacturing, storage and packaging. At the end of the day, it’s up to cannabis manufacturers to be proactive in ensuring cannabis edibles are safe to consume until regulations are mandated.

From The Lab

I Was Wrong… und das ist auch gut so!

By Dr. Markus Roggen
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I was wrong. And that’s a good thing! Based on all available data, I assumed that evaporating ethanol from a cannabis oil/ethanol solution would result in terpene loss. As it turns out, it doesn’t. There are so many beliefs and assumptions about cannabis: Cannabis cures cancer!1 Smoking cannabis causes cancer!2 Sativas help you sleep; Indicas make you creative!3,4 CBD is not psychoactive!5 But are these ‘facts’ backed by science? Have they been experimentally tested and validated?

I postulated a theory, designed experiments to validate it and evaluated the results. Simply putting “cannabis backed by science” on your label does not solve the problem. Science is not a marketing term. It’s not even a fixed term. The practice of science is multifaceted and sometimes confusing. It evolved from the traditional model of Inductivism, where observations are used in an iterative process to refine a law/theory that can generalize such observations.6 Closely related is Empiricism, which posits that knowledge can only come from observation. Rationalism, on the other hand, believes that certain truths can be directly grasped by one’s intellect.7 In the last century, the definition of science was changed from the method by which we study something, such as Inductivism or Rationalism, and refocused on the way we explain phenomena. It states that a theory should be considered scientific if, and only if, it is falsifiable.8 All that means is that not the way we study something is what makes it scientific, but the way we explain it.

I wonder how can we use empirical observations and rational deliberations to solve the questions surrounding cannabis? And more importantly, how can we form scientific theories that are falsifiable? Cannabis, the plant, the drug, has long been withheld from society by its legal status. As a result, much of what we know, in fact, the entire industry has thrived in the shadows away from rigorous research. It’s time for this to change. I am particularly concerned by the lack of fundamental research in the field. I am not even talking about large questions, like the potential medical benefit of the plant and its constituents. Those are for later. I’m talking about fundamental, mundane questions like how many lumens per square centimetre does the plant need for optimal THC production? What are the kinetics of cannabis extraction in different solvents? What are the thermodynamics of decarboxylation? Where do major cannabinoids differ or align in terms of water solubility and viscosity?

The lack of knowledge and data in the cannabis field puts us in the precarious position of potentially chasing the wrong goals, not to mention wasting enormous amounts of time and money. Here’s a recent example drawn from personal experience:Certainly, I cannot be the only one who has made an incorrect assumption based on anecdotes and incomplete data?

Some of the most common steps in cannabis oil production involve ethanol solutions. Ethanol is commonly removed from extraction material under reduced pressure and elevated heat in a rotary evaporator. I expected that this process would endanger the terpenes in the oil – a key component of product quality. My theory was that volatile terpenes9 would be lost in the rotary evaporator during ethanol10 removal. The close values of vapor pressure for terpenes and ethanol make this a reasonably assumed possibility.11 In the summer of 2018, I finally got the chance to test it. I designed experiments at different temperatures and pressures, neat and in solution, to quantify the terpene lost in ethanol evaporation. I also considered real life conditions and limitations of cannabis oil manufacturers. After all the experiments were done, the results unequivocally showed that terpenes do not evaporate in a rotary evaporator when ethanol is removed from cannabis extracts.12 As it turns out, I was wrong.

We, as an industry, need to start putting money and effort into fundamental cannabis research programs. But, at least I ran the experiments! I postulated a theory, designed experiments to validate it and evaluated the results. At this point, and only this point, can I conclude anything about my hypothesis, even if that is that my working theory needs to be revised. Certainly, I cannot be the only one who has made an incorrect assumption based on anecdotes and incomplete data?

There is a particular danger when using incomplete data to form conclusions. There are many striking examples in the medical literature and even the casual observer might know them. The case of hormone replacement therapy for menopause and the associated risks of cardiovascular diseases showed how observational studies and well-designed clinical trials can lead to contradicting results.13 In the thirties of the last century, lobotomy became a cure-all technique for mental health issues.14 Dr. Moniz even won the Nobel Prize in Medicine for it.15 And it must come as no surprise when WIRED states “that one generation’s Nobel Prize-winning cure is another generation’s worst nightmare.”16 And with today’s knowledge is impossible to consider mercury as a treatment for syphilis, but that is exactly what it was used as for many centuries.17 All those examples, but the last one in particular should “be a good example of the weight of tradition or habit in the medical practice, […] of the necessity and the difficulties to evaluate the treatments without error.”18 There is the danger that we as cannabis professionals fall into the same trap and believe the old stories and become dogmatic about cannabis’ potential.

We, as an industry, need to start putting money and effort into fundamental cannabis research programs. That might be by sponsoring academic research,19 building in-house research divisions,20 or even building research networks.21 I fully believe in the need for fundamental cannabis research, even the non-sexy aspects.22 Therefore, I set up just that: an independent research laboratory, focused on fundamental cannabis research where we can test our assumptions and validate our theories. Although, I alone cannot do it all. I likely will be wrong somewhere (again). So, please join me in this effort. Let’s make sure cannabis science progresses.


References

  1. No, it does not. There are preliminary in-situ studies that point at anti-cancer effects, but its more complicated. The therapeutic effects of Cannabis and cannabinoids: An update from the National Academies of Sciences, Engineering and Medicine report, Abrams, Donald I., European Journal of Internal Medicine, Volume 49, 7 – 11
  2. No, it does not. National Academies of Sciences, Engineering, and Medicine. 2017. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. Washington, DC: The National Academies Press. https://doi.org/10.17226/24625.
  3. No, it does not. The chemical profile of the plant dictates the biological effects on humans, not the shape of the leaf.  Justin T. Fischedick, Cannabis and Cannabinoid Research, Volume: 2 Issue 1: March 1, 2017
  4. Indica and Sativa are outdated terms. Piomelli D, Russo EB. The Cannabis sativa versus Cannabis indica debate: An Interview with Ethan Russo, MD. Cannabis Cannabinoid Res 2016; 1: 44–46.
  5. No, it is. CBD’s supposed “calming effects” is indeed a psychoactive effect. However, it is not intoxicating like THC. Russo E.B., Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects.Br. J. Pharmacol. 2011; 163: 1344-1364
  6. As attributed to Francis Bacon.
  7. See the work by philosopher Baruch Spinoza.
  8. As theorized by Karl Popper.
  9. Monoterpenes have a vapor pressure in the low to mid hundreds of Pascals at room temperature.
  10. Vapor pressure of 5.95 kPa at 20˚C.
  11. Furthermore, there is always the possibility of azeotropes in complex mixtures. Azeotropes are mixtures of two or more liquids that have different boiling points individually, but in mixture boil together.
  12. Terpene Retention via Rotary Evaporator Application Note, Heidolph North America
  13. https://www.pharmaceutical-journal.com/research/review-article/establishing-the-risk-related-to-hormone-replacement-therapy-and-cardiovascular-disease-in-women/20202066.article?firstPass=false
  14. https://psychcentral.com/blog/the-surprising-history-of-the-lobotomy/
  15. https://en.wikipedia.org/wiki/António_Egas_Moniz
  16. https://www.wired.com/2011/03/lobotomy-history/
  17. https://www.infezmed.it/media/journal/Vol_21_4_2013_10.pdf
  18. https://www.ncbi.nlm.nih.gov/pubmed/11625051
  19. Canopy Growth funds a professorship of cannabis science at UBC. Tilray collaborates with UCSD on a phase I/II clinical trial.
  20. For examples see: NIBR, PMISCIENCE.
  21. For examples see: CEMI, theAIRnet, Future Sky.
  22. Research that does not lead to short-term stock value spikes but long-term progress