The View from Texas
Restrictive legislation won’t prevent efforts to progress cannabis research
Kevin Schug | | Opinion
The Lone Star State has enormous untapped potential. High-quality instrumentation and plentiful manpower at institutions such as The University of Texas at Arlington could provide the perfect platform upon which a thriving cannabis research industry might grow. The obstacle? The usual suspect: restrictive legislature. Though we are now able to work with hemp, THC-containing forms of the plant remain off limits. Even if we did pursue a license from the Drug Enforcement Administration (DEA), access to interesting strains (endemic in Oregon, Colorado and Washington) remains prohibited. Perhaps the opportunity to work with hemp without a requirement for the DEA’s blessing will open new doors – at least, that’s the hope; in such a rapidly growing industry, every man and his dog are looking to get a slice of the pie.
Our group remains undeterred: we’ve delved into cannabinoid and terpene research with aplomb, using the availability of a growing number of DEA-exempt chemical standards to our advantage. In early conversations, I was astounded by the number of people who argued that it was impossible to analyze cannabinoids using gas chromatography (GC). Liquid chromatography (LC) by contrast, is very well suited to cannabinoid analysis – holding the beacon as industry standard. Yet, GC, though certainly more technically challenging, should not be disregarded (1, 2, 3). The key consideration is derivatization of the cannabinoids; this preserves the carboxylic acid functionalities, which would otherwise be removed in the hot injection port of the GC instrument, and improves isomer differentiation. Having explored the utility of GC for cannabinoid analysis, we have also researched and published a comprehensive review of techniques used for the analysis of natural cannabis products (4).
This initial foray into cannabis analysis provided a much-needed spark. It’s become clear that high efficiency separations using LC – coupled to high-resolution mass spectrometry (MS) and tandem MS – hold real promise for cannabinoid discovery. Our group has also spent a considerable amount of time cataloging fragmentation pathways for cannabinoid ions generated by different ionization modes, which may help in both discovery efforts and the study of biosynthetic pathways in which these new cannabinoids are involved. Access to novel strains will only accelerate this progress
At the same time, we’ve also pioneered the use of vacuum UV spectroscopy for GC detection, which holds great potential for terpene characterization. Now, our efforts have turned towards the novel application of a commercial, on-line supercritical fluid extraction–supercritical fluid chromatography (SFE-SFC)-MS instrument. This system could be used to bridge analysis of a great range of different classes of compounds from cannabis plants – or even edibles.
It’s easy to get excited by the role of analytical science in advancing the cannabis industry. Current efforts are just scratching the surface; as new therapeutic avenues for cannabinoids continue to emerge, they will need to be supported by high-efficiency, high-performance analytical methods. In short, there’s plenty of (analytical) exploring left to do – even for latecomers.
- A Leghissa et al., “Determination of cannabinoids from a surrogate hops matrix using multiple reaction monitoring gas chromatography with triple quadrupole mass spectrometry”, J Sep Sci, 41, 459 (2018). DOI: 10.1002/jssc.201700946
- A Leghissa et al., “Determination of the metabolites of Δ9-tetrahydrocannabinol in urine and plasma using multiple reaction monitoring gas chromatography with triple quadrupole mass spectrometery”, Sep Sci Plus, 1, 43 (2018). DOI: 10.1002/sscp.201700006
- A Leghissa et al., “Detection of cannabinoids and cannabinoid metabolites using gas chromatography with vacuum ultraviolet spectroscopy”, Sep Sci Plus, 1, 37 (2018). DOI: 10.1002/sscp.201700005
- A Leghissa et al., “A review of methods for the chemical characterization of cannabis natural products”, J Sep Sci, 41, 398 (2018). DOI: 10.1002/jssc.201701003