Characterization of the Pyrolysis Patterns of 44 Synthetic Cannabinoids and Their Application in Illicit Drug Analysis

The toxicological research and analysis of synthetic cannabinoids (SCs) have been the focus of scientists. SCs often cause severe acute intoxication after smoking, which may be related to the pyrolysis products formed during the heating process. However, the toxicology studies in vitro and in vivo are hampered by the lack of data on pyrolysis products. Moreover, SCs are diverse and rapidly updated, and the detection of SCs is always a step behind the changes in the illegal market. Here, 44 SCs were analyzed using pyrolysis-gas chromatography/mass spectrometry at 300, 600, and 800 ℃, respectively. The pyrolysis patterns of different SCs under the oxygen-free condition were proposed, based on the pyrolysis products. The shared and characteristic pyrolysis products of 44 SCs were obtained and employed as analytical markers for SCs identification. SCs in one seized e-liquid sample were accurately identified on the basis of the shared and characteristic pyrolysis products. The pyrogram profiles obtained by pyrolyzing SC standards at 600 ℃ were characteristic and reproducible. Therefore, a pyrogram library containing 44 entries for SCs was built through Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine. The pyrogram fingerprinting was used to identify eight unknown SC powders successfully. The results demonstrate the great potential of the pyrolysis pattern of SCs in drug analysis.