Extraction, identification and detection of synthetic cannabinoids found pre-ban in herbal products in Victoria, Australia

Measures to control the expanding use of synthetic cannabinoids demand new analytical methodology to identify and determine compounds within this rapidly evolving class. Herein, we identify seven synthetic cannabinoids (AM-2201, UR-144, XLR-11, A796,260, 5F-AKB48, PB-22 and 5F-PB-22) present in eleven herbal products sold in Victoria, Australia, prior to their ban in 2014, using a combination of GC-MS, HPLC, ESI-MS, and NMR. In aid of this work, we synthesised the synthetic cannabinoids AM-2201 and 5F-AKB48. We then explore for the first time, the chemiluminescence detection of synthetic cannabinoids using three commonly used reagents: permanganate, manganese(IV), and tris(2,2′‐bipyridine)ruthenium(III). Using the permanganate reagent, no chemiluminescence signal was obtained, but the manganese(IV) and tris(2,2′‐bipyridine)ruthenium(III) reagents gave analytically useful responses with all synthetic cannabinoids under investigation except 5F-AKB48. Calibration curves for PB-22, 5F-PB-22, AM-2201 and 5F-AKB48 prepared using HPLC with UV absorbance and/or chemiluminescence detection were used to determine the total cannabinoid content extracted with methanol (1 mL) from of six of the herbal products (10 mg), which ranged from 0.072 to 0.77 mg.