Objective To investigate a strategy for the qualitative analysis of synthetic cannabinoids with unknown structures in the absence of reference standards. Methods Column chromatography was used to purify the suspicious sample and obtain high-purity prepared sample. The prepared sample was analyzed and its structure was confirmed by comprehensive use of gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS), and nuclear magnetic resonance spectroscopy (NMR). The differences between collision-induced dissociation (CID) and electron-activated dissociation (EAD) fragmentation modes of UPLC-QTOF-MS were compared, and the structure was finally confirmed. Results A 129.9 mg high-purity prepared sample was obtained through column chromatography. Through comprehensive analysis of GC-MS, UPLC-QTOF-MS, and NMR, it was confirmed that the unknown synthesized cannabinoid was N-(adamantane-1-yl)-2-[1-(4-fluorobenzyl)-1H-indole-3-yl]acetamide, abbreviated as AFUBIATA. Comparison of the CID and EAD fragmentation modes revealed that the EAD provided richer fragment ion information, which facilitated the structural elucidation of the unknown substance. Conclusion This study obtained a high-purity sample through column chromatography. By comprehensively utilizing GC-MS, UPLC-QTOF-MS and NMR information, the structural elucidation of unknown synthetic cannabinoids was achieved. This information can assist forensic science laboratories in identifying this substance or similar structural compounds.
