LC-MS/MS quantitation of phytocannabinoids and their metabolites in biological matrices

Marijuana (Le., 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.