A reliable method for the separation and detection of synthetic cannabinoids by supercritical fluid chromatography with mass spectrometry, and its application to plant products

Abstract

A reliable method using supercritical fluid chromatography with mass spectrometry (SFC-MS) was developed for cannabinoids using compressed carbon dioxide (CO2) and methanol as the mobile-phase. The cannabinoids, i.e., cannabicyclohexanol (CCH: cis-isomer), trans-CCH, 5-(1,1-dimethylheptyl)-2-[(1R,3S)-3-hydroxycyclohexyl]-phenol (CP-47497), 5-(1,1-dimethylheptyl)-2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl)-cyclohexyl]-phenol (CP-55940), 3-(1,1'-dimethylheptyl)-6aR,7,10,10aR-tetrahydro-1-hydroxy-6,6-dimethyl-6Hdibenzo[b,d]pyran-9-methanol (HU-210), 2-[1R-3-methyl-6R-(1-methylethenyl)-2-cyclohexen-1-yl]-5-pentyl-1,3-benzenediol (CBD), (1-pentyl-1H-indol-3-yl)-1-naphthalenyl-methanone (JWH-018), (1-butyl-1H-indol-3-yl)-1-naphthalenyl-methanone (JWH-073) and 1-(1-pentyl-1H-indol-3-yl)-2-(2-methoxyphenyl)-ethanone (JWH-250), were determined within 12 min using a conventional column (2-EP) for SFC. Furthermore, two optical isomers of CCH and trans-CCH were completely and rapidly separated by a chiral stationary phase column (AMY1). A highly sensitive detection (0.002-3.75 ppb) was also obtained by these methods using 2-EP and AMY1 columns. These methods were applied to the qualitative and quantitative determination of cannabinoids in dried plant products. Although the concentration and species were different in the products, JWH-018, JWH-073 and CCH, including the cis-isomer, trans-isomer and the optical isomers, were detected in the products. Therefore, the proposed SFC-MS method seems to be useful as an alternative method to GC-MS and LC-MS for illegal drugs, such as cannabinoids.