Analysis of 62 synthetic cannabinoids by gas chromatography–mass spectrometry with photoionization

Abstract

Gas chromatography–mass spectrometry (GC–MS) in electron ionization (EI) mode is one of the most commonly used techniques for analysis of synthetic cannabinoids, because the GC–EI-MS spectra contain characteristic fragment ions for identification of a compound; however, the information on its molecular ions is frequently lacking. To obtain such molecular ion information, GC–MS in chemical ionization (CI) mode is frequently used. However, GC–CI-MS requires a relatively tedious process using reagent gas such as methane or isobutane. In this study, we show that GC–MS in photoionization (PI) mode provided molecular ions in all spectra of 62 synthetic cannabinoids, and 35 of the 62 compounds showed only the molecular radical cations. Except for the 35 compounds, the PI spectra showed very simple patterns with the molecular peak plus only a few fragment peak(s). An advantage is that the ion source for GC–PI-MS can easily be used for GC–EI-MS as well. Therefore, GC–EI/PI-MS will be a useful tool for the identification of synthetic cannabinoids contained in a dubious product. To the best of our knowledge, this is the first report to use GC–PI-MS for analysis of synthetic cannabinoids.

Intermolecular through‐space charge transfer enabled by bicomponent assembly for ultrasensitive detection of synthetic cannabinoid JWH‐018

“…The strong face-to-face aromatic ππ stacking interaction between the naphthalene ring of the probe and the indole ring of JWH-018 is indicated by the following four BCPs (5-8) with H(r)/ρ(r) in the range of 0.08-0.11. The last six BCPs (9)(10)(11)(12)(13)(14) are located between the alkyl chains of the probe and JWH-018, with H(r)/ρ(r) in the range of 0.13-0.28, demonstrating the moderate van der Waals interaction between the two molecules. Therefore, all these three types of intermolecular interactions as a whole serve as the driving force for the effective assembly of the probe and the JWH-018.…”

Gas chromatographic analysis of naturally occurring cannabinoids: A review of literature published during the past decade

“…flame ionisation detector (FID) and mass spectrometry (MS), is one of those analytical tools that has been used extensively to analyse cannabinoids. [5][6][7][8] Over the past decade, with the advancement of computational tools, MS databases, and various advanced detection technologies, GC has become one of the major tools in forensic, pharmacokinetic and phytochemical analysis of naturally occurring cannabinoids. This review aims to capture the developments in GC methods applied to cannabinoids analysis since 2009, and to appraise the scientific publications in this topic published in the past decade.…”

“…It can be mentioned that GC-MS analysis of cannabinoids is not necessarily restricted to the use of these two ionisation techniques, rather, other ionisation techniques, e.g. photo ionisation (PI) technique, 6 are also in use.…”

Smart Miniature Mass Spectrometer Enabled by Machine Learning

“…The mass spectra produced from an EI source generally contain extensive fragments, which results in very complex mass spectra for mixtures. As an alternative soft ionization method, photoionization possesses the merits of good ionization efficiency, high molecular ion yield, and simplified spectrum interpretation. − The advantages of small size and low power consumption also bridge it with miniaturized mass spectrometers. Some different kinds of portable mass spectrometers based on vacuum ultraviolet (VUV) photoionization have been developed during the past decades. ,− Volatile and semivolatile compounds, for instance, illegal drugs, could be analyzed. − Recently, a mini-MS with a continuous atmospheric inlet was developed in our lab (namely, Brick-V), in which photoionization was integrated with an ion funnel .…”