Mass Spectrometry Center

Cannabis Testing

As medicinal and recreational cannabis markets continue to grow, global demands for cannabis testing keep rising. The cannabis industry must ensure product quality, regulatory compliance and safety. The Western Illinois Mass Spec Center sincerely invites the cannabis industry in the Illinois state for collaboration in cannabis-testing solutions, from accurate potency testing and terpene profiling to contaminant testing for residual solvents, pesticides, and mycotoxins.

Validation of a LC-DAD-ESI/MS/MS method for the accurate measurement of THC and THCA-A among twenty cannabinoids in various products of Cannabis

In 2020, the National Institute of Justice (NIJ) has funded Dr. Liguo Song $160,181 for the titled project (Award #: 2020-DQ-BX-0021).

Cannabis is a cosmopolitan species that is well known to produce cannabinoids. It has two primary species commonly known as hemp and marijuana. Marijuana is a psychotropic drug because of Δ9-THC, a heat-triggered decomposition product of Δ9-THCA-A that is biosynthesized in the fresh plant. Hemp, which is used to produce many consumer products, from fibers to edibles, is characterized by low levels of THC and high levels of CBD, a non/antipsychotropic compound with recently accepted medical use.

Cannabis plants exert psychotropic effects when Δ9-THC concentration approximates 1%. In the Federal Controlled Substance Act of 1970, cannabis was defined as a Schedule 1 substance, which made cultivation and use of marijuana and hemp illegal. Nevertheless, recently 11 states and the District of Columbia have passed recreational marijuana laws, while 34 states and the District of Columbia have passed medical marijuana laws. In December 2018, Congress enacted the 2018 Farm Bill, which amended the statutory definition of cannabis to exclude hemp, with a Δ9-THC concentration of not more than 0.3% on a dry-weight basis.

Currently, there is an urgent need of validated methods to measure the total Δ9-THC concentration in various products of Cannabis by the crime laboratories because the currently available GC-MS method is unable to directly measure the precursor of Δ9-THC, i.e. Δ9-THCA-A, due to its nonquantitative thermal decomposition under GC-MS conditions. Conversely, many LC-DAD and LC-ESI/MS/MS methods have been published lately, because the LC separation can avoid thermal stress so that acidic cannabinoids can be directly analyzed. However, drawbacks of these methods include limited applicability, insufficient selectivity, flawed recovery experiments, and rare consideration of matrix effect. This project seeks to validate a LC-DAD-ESI/MS/MS method, which is based on our recently developed LC-ESI/MS/MS method for the simultaneous measurement of 20 cannabinoids in dried hemp flowers, for the accurate measurement of Δ9-THC and Δ9-THCA-A among 20 cannabinoids in a wide variety of Cannabis products such as dried flowers, concentrates, edibles and topical, a total of 68 different types of sample, with key characteristics including broad applicability, maximum selectivity, novel and specially designed recovery experiments, and best consideration of matrix effect. The method will be easily adopted by crime laboratories with different instrumentation because it will be easily dissected after our comprehensive study, e.g. a LC-UV method using a traditional UV detection, a LC-ESI/MS method using a single quadrupole, or a LC-ESI/MS/MS method using a triple quadrupole.

Peer-reviewed journal articles

  1. L.G. Song, S. Carlson, G. Valenzuela, M.D.S. Chao, S.B. Pathipaka, Development of a validated method for rapid quantification of up to sixteen cannabinoids using ultra-high-performance liquid chromatography diode-array detector with optional electrospray ionization time-of-flight mass spectrometry detection, J. Chromatogr. A 1670 (2022) 10. https://doi.org/10.1016/j.chroma.2022.462953. (Download data of study-level information in PDF).
  2. L.G. Song, G. Valenzuela, S. Carlson, Z. Dodson, M. Adisa, Potency testing of up to twenty cannabinoids by liquid chromatography diode array detector with optional electrospray ionization time-of-flight mass spectrometry, Anal. Chim. Acta 1207 (2022) 9. https://doi.org/10.1016/j.aca.2022.339827. (Download data of study-level information in PDF).
  3. L.G. Song, G. Meyer, E. Adejumo, E. Jovanovich, L. LeBlance, J. Provis, Potency testing of up to sixteen cannabinoids in hemp-infused edibles using liquid chromatography diode array detector with optional confirmation of identity by electrospray ionization time-of-flight mass spectrometry, Food Chem. 417 (2023) 9. https://doi.org/10.1016/j.foodchem.2023.135819.(Download data of study-level information in PDF).
  4. G. Meyer, M. Adisa, Z. Dodson, E. Adejumo, E. Jovanovich, L.G. Song, A liquid chromatography electrospray ionization tandem mass spectrometry method for quantification of up to eighteen cannabinoids in hemp-derived products, J. Pharm. Biomed. Anal. 115847 (2023) 10. https://doi.org/doi:10.1016/j.jpba.2023.115847. (Download data of study-level information in PDF).

Quantification of psychotropic cannabinoids in newly emerging hemp-derived products and evaluation of their stability and interconversion during storage

In 2023, the National Institute of Justice (NIJ) has funded Dr. Liguo Song $251,505 for the titled project (Award #: 15PNIJ-23-GG-04234-RESS).

Since the 2018 Farm Bill excluded hemp from the statutory definition of cannabis with a Δ9-THC (tetrahydrocannabinol) concentration not more than 0.3%, psychotropic cannabinoids other than Δ9-THC, which are double-bond position isomers, homologues and analogues of Δ9-THC, including Δ8-THC, Δ10-THC, THCP (tetrahydrocannabiphorol), THC-O-acetate, HHC (hexahydrocannabinol), and HHC-O-acetate, have been sold online and by brick-and-mortar retailers across the U.S., based on legal arguments that the 2018 Farm Bill legalized them due to their natural presence in hemp, despite in amounts too small to produce psychotropic effects, and/or because they are derived from CBD (cannabidiol) that are legally extracted from hemp. The ever-increasing marketing of psychotropic cannabinoids in newly emerging hemp-derived products has made it clear that their contents must be accurately measured and their stability and interconversion during storage should be clearly understood so that State and federal regulators can make informed decisions for a better regulated hemp market.

Double-bond position isomers of Δ9-THC are produced by non-specific isomerization reactions of CBD, resulting in a mixture probably containing Δ8-THC, Δ9- THC, Δ10- THC, Δ11- THC, Δ6a,10a- THC, Δ6a,7- THC, Δ7-THC, CBD, CBC (cannabichromene), CBL (cannabicyclol) and CBT (cannabicitran). Their quantification requires baseline separation of all eleven isomers because their differentiation using a triple quadrupole was proven unachievable by us, which is a significant challenge because even the baseline separation of Δ8-/Δ9-THC was not achieved by many published methods. So far, the maximum number of cannabinoids that have been baseline separated was twenty by us, including Δ8-THC, Δ9-THC, CBD, CBC, CBL and CBT. With this project, a LC-DAD-ESI/MS/MS methods using a high-resolution mass spectrometer will be developed after a systematic separation optimization using four carefully selected LC columns with varying selectivity towards cannabinoids. The optimized method will be further applicable for the quantification of homologues and analogues of Δ9-THC due to larger structural and mass differences. The method will be easily adopted by crime laboratories with different instrumentation because it will be easily dissected after our comprehensive study, e.g., a LC-UV method using a traditional UV detection, a LC-ESI/MS method using a single quadrupole, or a LC-ESI/MS/MS method using a triple quadrupole.

The stability of psychotropic cannabinoids, including Δ9-THC, during storage has not been well studied so far. This project further seeks to understand the reaction kinetics of psychotropic cannabinoids during chemical degradation. It will provide valuable information about the shelf-life of psychotropic cannabinoids under different storage conditions.

 

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