Nanotechnology is used extensively in the food, cosmetics, and pharmaceutical industries, primarily in development and testing through instrumentation and microscopy, along with some advanced production techniques. The nascent medicinal and recreational cannabis markets have a similar relationship with nanotechnology.
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Nanotechnology-Based Instrumentation for Detecting Pesticides and Toxic Elements in Cannabis
There are estimated to be upwards of 180 million cannabis users in the United States, and cannabis use is increasing worldwide for medicinal and recreational purposes. Countries are increasing medicinal cannabis operations and relaxing laws around recreational cannabis use, and a high-level quality assurance (QA) industry is rising to meet the challenges this shift brings.
With the relatively recent change in cannabis’s legal status in various jurisdictions, requisite analytical standards for QA processes – not to mention safety and regulation – have had to be rapidly drawn up in the last few decades.
In 2019, a team of chemists and analytical toxicologists working at the University of Alberta, Edmonton, Canada, discussed what had then become a range of analytical methods for measuring cannabis for contamination. The study, published in the Journal of Environmental Sciences, celebrated the establishment of analytical methods – many of which rely on nanotechnology-based instrumentation – in an area where methodology had previously been dire or nonexistent, according to the authors.
The scientists discussed analytical challenges for detecting pesticides and toxic elements in cannabis, exploring the development of appropriate methods for this task.
They compared the effectiveness, cost, duration, and effort required for inspection methods based on nanotechnology, including atomic adsorption spectroscopy (AAS), atomic emission spectroscopy with inductively coupled plasma (ICP-AES), and ICP with mass spectrometry (ICP-MS).
The researchers demonstrated that while AAS is cheaper, its slow sample throughput and low sensitivity compared to ICP-AES led to a preference for the latter. However, ICP-MS was the superior method for testing, with the highest throughput and sensitivity. Researchers noted that its use is increasing in the cannabis industry, with techniques from other sectors easily adaptable for cannabis testing.
Researchers also identified a need to continue to increase the quantity and scope of quality control and testing in the cannabis industries – medicinal as well as recreational. Recommendations include elaborating on international quality standards, improving enforcement measures, and conducting further research into the extent of cannabis contamination.
Creating Nanomaterials from Cannabis Shells
A team of materials scientists and engineers from the Lanzhou University of Technology, China, recently used pyrolysis and activation of fructus cannabis shells to obtain a porous carbon material with a high specific surface area of 2389 m2 g-1.
The study, published in the journal Materials Research Express in 2018, used cannabis shells to create the carbon material because they are an easy to obtain source of biomass, and because they are already used as active electrode materials for supercapacitors.
The high specific surface area of the material obtained through pyrolysis makes it suitable for advanced supercapacitor applications. X-ray photoelectron spectroscopy (XPS), which is a nanotechnology method, was used to identify numerous oxygen groups in the carbon material, meaning the electrode can withstand wetting.
The electrochemical properties in the cannabis-based porous carbon were also remarkable. These included high specific capacitance, good rate capability, and superior cycling stability.
Cannabis Products Made with Nanotechnology
The Canadian newspaper, the Vancouver Sun, recently reported on controversy surrounding a new recreational cannabis product made with nanotechnology.
A Toronto-based cannabis producer – with a rival product – had claimed that cannabis products made with sonication represented potential health and safety risks to consumers and needed more testing before they should be recommended.
Sonication applies sound waves, usually in ultrasonic frequencies greater than 20 kHz, to agitate particles in a given sample. It is used to extract various compounds from plants, seaweeds, and microalgae.
Some cannabis producers are using sonication to produce cannabis nanoparticles in nanoemulsions, nanocrystals, and wax emulsions. The technique is already applied in pharmaceutical, cosmetic, food, and coating industries.
Producers claim that the nanotechnology technique results in cannabis products – and other food and pharmaceutical products – with more bioavailability.
However, critics say that nanoparticles are small enough to permeate the body’s tissues in ways neither producers nor consumers can really control. Another risk cited is accumulation: while this technology is approved for some medications, these are only intended for irregular or one-off consumption.
Recreational products using cannabis nanoparticles, on the other hand, may be used habitually. Critics say that the effects of this kind of use are as yet unclear, and we do not know the full implications of an accumulation of cannabis nanoparticles in human tissue.
The Future of Nanotechnology in Cannabis Science: More Standardization
At present, the cannabis sciences are facing challenges common to any nascent field: a lack of consensus around references and standards between laboratories around the world.
As cannabis science matures in the next few decades, laboratories, nanotechnology approaches and methods, and reference materials should all become standardized. This will enable more accurate testing and quality assurance, safer products, and continued growth in cannabis markets worldwide.
References and Further Reading
Craven, C. B., Wawryk, N., Jiang, P., Liu, Z., & Li, X. F. (2019). Pesticides and trace elements in cannabis: Analytical and environmental challenges and opportunities. Journal of Environmental Sciences. doi.org/10.1016/j.jes.2019.04.028.
Cuffari, B. (2021). Inter-Lab Variation within the Cannabis Industry. [Online] AZO Life Sciences. Available at: https://www.azolifesciences.com/article/Inter-Lab-Variation-within-the-Cannabis-Industry.aspx (Accessed on 13 May 2022).
Ducker, J. (2021). The Importance of Measuring Contaminants in Cannabis. [Online] AZO Life Sciences. Available at: https://www.azolifesciences.com/article/The-Importance-of-Measuring-Contaminants-in-Cannabis.aspx (Accessed on 13 May 2022).
Eagland, N. (2019). Scientists say nanotechnology in cannabis needs cautious approach, more research. [Online] Vancouver Sun. Available at: https://vancouversun.com/cannabis/cannabis-business/scientists-say-nanotechnology-in-cannabis-needs-cautious-approach-more-research/ (Accessed on 13 May 2022).
Li, K., et al. (2018). A porous carbon material from pyrolysis of fructus cannabis's shells for supercapacitor electrode application. Materials Research Express. doi.org/10.1088/2053-1591/aaad70.
Peshkovsky, A.S., et al. (2013). Scalable high-power ultrasonic technology for the production of translucent nanoemulsions. Chemical Engineering and Processing: Process Intensification. doi.org/10.1016/j.cep.2013.02.010.
Pusiak, R. J. P., et al. (2021). Growing pains: An overview of cannabis quality control and quality assurance in Canada. International Journal of Drug Policy. doi.org/10.1016/j.drugpo.2021.103111.