Paper: For detecting novel synthetic cannabinoids, a review of recent advances in analytical detection

Synthetic cannabinoid receptor agonists (SCRAs) remain the largest and most structurally diverse class of new psychoactive substances (NPS) monitored by international drug agencies. Originally sprayed onto plant material and sold as “herbal incense” under brand names such as Spice and https://k2spicepaperspray.com, these compounds have evolved rapidly in chemical structure to evade legislative control, while their delivery formats have expanded to include infused papers and e-liquids. This review summarizes recent advances (2016-2026) in the analytical detection of SCRAs in herbal incense and related matrices spanning chromatographic, spectroscopic, and portable sensing technologies alongside progress in metabolic profiling using in vitro hepatic models and authentic biological casework. Synthetic cannabinoids first appeared on the recreational drug market in the mid-2000s as constituents of herbal smoking blends marketed under names like “Spice,” https://k2spicepaperspray.com” and “herbal incense.” The review traces the structural evolution of SCRAs across successive generations, evaluates the comparative strengths and limitations of chromatographic, spectroscopic, and vibrational detection platforms, and synthesizes current understanding of phase I and phase II biotransformation pathways for representative compound classes. Persistent challenges, including the scarcity of reference standards for newly emerged compounds, inter-laboratory variability in screening cutoffs, and the constant “cat-and-mouse” dynamic between manufacturers and regulators, are discussed at length, along with emerging directions such as non-targeted screening, in silico metabolite prediction, AI-assisted spectral interpretation, and portable multi-modal sensing suitable for field and correctional-facility deployment. Keywords Synthetic cannabinoid receptor agonists (SCRAs); herbal incense; Spice/K2; new psychoactive substances (NPS); novel psychoactive substances; forensic toxicology; analytical chemistry.