Isomer-Specific Two-Color Double-Resonance IR2MS3 Ion Spectroscopy using a Single Laser: Identification of designer drugs

Designer drugs or NPS (novel psychoactive substances) are getting more and more popular on the global synthetic drug market. The chemical structures are closely related to traditional drugs, and they induce similar psychoactive effects. But trading is often a legal grey area and they can potentially cause severe health effects. At our lab, scientists identified isomeric designer drugs in a sample confiscated by the Amsterdam Police, using a single infrared laser for two-color infrared IR²MS³ experiments.

The capability of an ion trap mass spectrometer to store ions for an arbitrary amount of time allows the use of a single infrared (IR) laser to perform two-color double resonance IR–IR spectroscopic experiments on mass-to-charge (m/z) selected ions. In this single-laser IR²MS³ scheme, one IR laser frequency is used to remove a selected set of isomers from the total trapped ion population and the second IR laser frequency, from the same laser, is used to record the IR spectrum of the remaining precursor ions. This yields isomer-specific vibrational spectra of the m/z-selected ions, which can reveal the structure and identity of the initially co-isolated isomeric species. The use of a single laser greatly reduces the experimental complexity of two-color IR²MS³ and enhances its application in fields employing analytical MS.

Reference

Isomer-Specific Two-Color Double-Resonance IR²MS³ Ion Spectroscopy Using a Single Laser: Application in the Identification of Novel Psychoactive Substances, Fred A. M. G. van Geenen, Ruben F. Kranenburg, Arian C. van Asten, Jonathan Martens, Jos Oomens and Giel Berden, Analytical Chemistry (2021)

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Giel Berden