Citation

Smolianitski-Fabian E, Cohen E, Dronova M, Voloshenko-Rossin A, Lev O. Drug Test. Anal. 2018; 10(3): 474-487.

Affiliation

Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel.

Copyright

(Copyright © 2018, John Wiley and Sons)

DOI

10.1002/dta.2247

PMID

28688175

Abstract

Gas chromatography thermal-electron ionization mass spectrometry (GC-EI-MS) is an established method for the identification of mind-altering substances and is routinely used by forensic laboratories. However, some commonly analyzed drugs of abuse, relating to the synthetic cannabinoids receptor agonist group (SCs), pose a challenge for this conventional technique. As the molecular cation radicals of many excited SCs are labile within the ion source, the relative abundance of the molecular ions obtained by the GC-EI-MS is often too small to allow discrimination of structurally related drugs. In contrast, cold-electron ionization (cold-EI) method allows the enhancement and clear identification of the molecular ions, while maintaining the ability to compare unknown analytes with comprehensive mass spectrum libraries. This technique was explored for mass-spectrometric identification and unambiguous differentiation of 15 emerging synthetic cannabinoids found on the drug market in Israel and elsewhere. The current method was demonstrated to discriminate pairs of closely related SCs: FUB-PB-22 and FDU-PB-22, and 5F-PB-22 and NM-2201. In addition, the dependence of the molecular ion enhancement on the cold-EI parameters was examined. Finally, analysis of SCs from seized street samples provided by the Israeli police demonstrates the enhanced identification power of GC-cold-EI-MS.

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Language: en

Keywords

cold-EI; gas chromatography-mass spectrometry; molecular peak enhancement; supersonic molecular beam; synthetic cannabinoids receptor agonists