Analysis of synthetic cannabinoid agonists and their degradation products after combustion in a smoking simulator

Synthetic cannabinoids are a major class of NPS with a high impact on analytical, forensic and toxicological fields. The main route of administration of synthetic cannabinoids is through inhalation, delivered by smoking a conventional or electronic cigarette, pyrolysis possibly altering the nature of these compounds and resulting in unknown combustion products with unknown biological activity/toxicology. In this study, a twin-trap smoking inhalation model that simulates human inhalation has been developed. The smoking simulator allows the efficient trapping of the combustion products. Analysis using UHPLC-TOF-ESI-MS and GC-MS allowed the detection of all six synthetic cannabinoids tested in the smoking simulator. A novel combustion product of MDMB-CHMICA was identified, a dihydro-1H-pyridoindole-dione with its structure and mechanism of formation proposed. This study of SC combustion products provides markers which may be useful for drug analysts and toxicologists in examining samples obtained from suspected SC users/abusers.