Rapid identification of synthetic cannabinoids in herbal samples via direct analysis in real time mass spectrometry.

Rationale: Dozens of synthetic cannabinoid analogs purposefully meant to circumvent legal restrictions associated with controlled substances continue to be manufactured and promoted as producing 'legal highs'. These designer drugs are difficult to identify in conventional drug screens not only because routine protocols have not been developed for their detection, but also because their association with complex plant matrices during manufacture generally requires labor-intensive extraction and sample preparation for analysis. To address this new and important challenge in forensic chemistry, Direct Analysis in Real Time Mass Spectrometry (DART-MS) is applied to the analysis of these designer drugs.

Methods: DART-MS was employed to sample synthetic cannabinoids directly on botanical matrices. The ambient ionization method associated with DART-MS permitted the analysis of solid herbal samples directly, without the need for extraction or sample preparation. The high mass resolution time-of-flight analyzer allowed identification of these substances despite their presence within a complex matrix and enabled differentiation of closely related analogs.

Results: DART-MS was performed to rapidly identify the synthetic cannabinoids AM-251 and JWH-015. For each cannabinoid, three hundred micrograms (300 µg) of material was easily detected within an excess of background matrix by mass.

Conclusions: New variations of herbal blends containing a wide range of base components and laced with synthetic cannabinoids are being produced, making their presence difficult to track by conventional methods. DART-MS permits rapid identification of trace synthetic cannabinoids within complex biological matrices, with excellent sensitivity and specificity compared with standard methods.