Synthetic cannabinoids in e-liquids: a proton and fluorine NMR analysis from a conventional spectrometer to a compact one.

Introduction:
This text provides an overview of a study that analyzed the composition of electronic cigarette (e-cigarette) liquids using various nuclear magnetic resonance (NMR) techniques and gas chromatography-mass spectrometry (GC-MS). The study aimed to identify and quantify the synthetic cannabinoids (SCs) and flavoring compounds present in the e-liquids.

Key Points:

* The study used 13 e-liquid samples from customs seizures and analyzed them using high-field (hF) and low-field (LF) NMR, GC-MS, and other analytical techniques.
* The hF NMR spectra of all 13 samples allowed the detection of matrix signals, synthetic cannabinoids, and flavoring compounds. Five SCs were identified in the samples, including JWh-210, 5F-MDMB-PICa, 5F-aDB, 5F-aKB48, and aDB-FUBINaCa.
* The LF NMR experiments were recorded on a benchtop NMR spectrometer operating at a frequency of 59.7 Mhz for 1h and 56.17 Mhz for 19F. The spectra were processed using the MNova 11.0 software.
* The T1 measurements of protons and fluorine nuclei were carried out using the inversion-recovery pulse sequence method. The recording parameters were optimized to gain full relaxation of the nuclei for quantitative experiments.
* The amounts of SCs in each e-liquid sample were measured using hF proton and fluorine NMR as reference quantitative methods. The results showed that the SCs in e-liquids could be successfully quantified by NMR, and an accurate 19F NMR quantification of fluorinated SCs could be implemented on a compact LF NMR spectrometer without requiring any specific standard compound.
* The 13 e-liquids contained variable concentrations of SCs, ranging from around 1 mg/mL to more than 20 mg/mL. The toxicological implications of these findings were discussed, emphasizing the high CB1/CB2 binding potency of the third generation of SCs and the potential health risks associated with their use.

Main Message:
The study demonstrates the utility of NMR and GC-MS techniques in identifying and quantifying the composition of e-liquids, including the detection of synthetic cannabinoids and flavoring compounds. The findings highlight the need for regulatory oversight and monitoring of e-cigarette liquids to ensure their safety and compliance with quality standards. The study also underscores the importance of continued research to better understand the potential health risks associated with the use of e-cigarettes and synthetic cannabinoids.

Wu N, Danoun S, Balayssac S, Malet-Martino M, Lamoureux C, Gilard V. Synthetic cannabinoids in e-liquids: a proton and fluorine NMR analysis from a conventional spectrometer to a compact one. Forensic science international. 2021;324:110813. doi:10.1016/j.forsciint.2021.110813