Analysis of Synthetic Cannabinoids in Botanical Material: A Review of Analytical Methods and Findings

Synthetic cannabinoid analogs have gained a great deal of attention from the forensic community within the last four years. The compounds found to be of most interest to forensic practitioners include those of the following series: JWH, CP, HU, AM, WIN, RCS, and most recently, XLR and UR. Structurally the HU compounds are most similar in structure to Δ9-tetrahydrocannabinol (THC), the main psychoactive component of marijuana. The novel compounds include cyclohexylphenols, naphthoylindoles, naphthylmethylindoles, naphthylmethylindenes, benzoylindoles, naphthoylpyrroles, phenylacetylindoles, adamantoylindoles, and tetramethylcyclopropylindoles. Many of these compounds are cannabinoid receptor agonists and were originally synthesized for medical research purposes but have recently been appropriated into the illicit drug market. Their psychoactive effects, mimicking those of marijuana, as well as their indeterminate legal status, have made them popular for recreational use. Solutions of the compounds dissolved in organic solvents are sprayed onto botanical material and sold as "herbal incense" products via the Internet, and in smoke shops, convenience stores, and gas stations around the world. Many of the products are labeled "Not for human consumption" in an attempt to circumvent legislation that bans the sale and manufacture of certain compounds and their analogs for human use. The compounds that were first detected following forensic analysis of botanical materials included JWH-018, JWH-073, and CP 47,497 (C7 and C8 homologs). However, in the four years since their appearance the number of compounds has grown, and additional diverse classes of compounds have been detected. Governments worldwide have taken action in an attempt to control those compounds that have become widespread in their regions. This article discusses the history of synthetic cannabinoids and how they have been detected in the illicit drug market. It also discusses the analytical methods and techniques used by forensic scientists to analyze botanical products obtained via the Internet or from law enforcement investigations and arrests.