Bualuang ASEAN Chair Professorship Seminar on 31 October 2019 was about “Cannabis and Human Health and Wellness Industries” conducted by Prof. Raimar Löbenberg (Director of the Drug Development and Innovation Center, University of Alberta, Canada) and Prof. Buncha Ooraikul (Bualuang ASEAN Chair Professor from Agricultural, Food and Nutritional Science, University of Alberta, Canada). The seminar was organized by Assoc.Prof. Arunporn Itharat (Center of excellence in Applied Thai Traditional Medicine, Thammasat University)
(Reference: LC-MS/MS quantitation of phytocannabinoids and their metabolites in biological matrices.
Abd-Elsalam WH1, Alsherbiny MA2, Kung JY3, Pate DW4, Löbenberg R5.)
Marijuana (i.e., cannabis) and its derivatives are considered the most commonly used of illicit drugs. Within the last two decades, phytocannabinoids and their synthetic analogues have emerged as potential medicines for the treatment of various disorders via targeting of the endocannabinoid system. Recently, some countries have legalized (medicinal/recreational) cannabis, which now allows for more research to be conducted. Accordingly, sensitive and specific analytical assays are required to identify and quantify these compounds in different human matrices. These analytical approaches were developed using mass spectrometric detection, where LC-MS/MS specifically has become the mainstay for the quantitative analysis of tetrahydrocannabinol and other cannabinoids. This is due to its superior selectivity and sensitivity, and ability to determine free and conjugate analytes within the same analysis. This tabular review of such methods is prefaced by a short overview of the major cannabinoids and some of their physiological actions.
Multistage mass spectroscopic (MSn) analysis and high-resolution MS offer selectivity, with subsequent reduction in sample preparation procedures. Advances in the detection and quantitation of cannabinoids and their metabolites beyond the ppb level in various biological matrices have been achieved by LC-MS/MS by a combination of better sample preparation and derivatization methods. LC methods are preferable compared to GC techniques, especially if the sample might contain the labile carboxylic acid form of any phytocannabinoid of interest.
Further, some LC methods do not require time-consuming or complicated sample preparation or derivatization, except if an enhanced lower limit of detection or quantitation is needed. Versatile online or offline SPE pre-treatment of samples can facilitate automation of cannabinoid analyses, and automated detection and quantitation could be utilised for forensic, clinical and toxicological applications. LC-MS with electro spray ionisation as well as the usual ionisation techniques in both positive and negative modes facilitate the detection of cannabinoids in samples such as hair, oral fluid, and urine alongside the smaller volumes used for DBS. In particular, maturation of direct DBS methods allow them to be easily implemented in analytical laboratories [99,100].
Finally, metabolomic approaches coupled with multivariate data analysis could be utilised in the future for the identification and differentiation of immediate or prior cannabinoid exposure. Tandem mass spectrometry coupled with liquid chromatography will enrich not only the study of potential cannabinoid-pharmaceutical interactions, but will also enable more detailed pharmacokinetic and pharmacodynamic studies. These advances will benefit the development of better cannabis-derived products for medical and recreational purposes.