光イオン化ガスクロマトグラフィー/質量分析法による危険ドラッグの分析及びデータベースの構築 Analysis of New Psychoactive Substances (NPSs) by GC/MS with Photoionization and Construction of Private Reference Library
Photoionization (PI), a soft ionization technique, can provide molecular ion information without causing complete fragmentation of the molecule. Gas chromatography/mass spectrometry in the PI mode (GC-PI/MS) involves ionizing sample molecules with light energy at approximately 8–10 eV. In this study, we examined the potential application of GC-PI/MS for the analysis of 209 new psychoactive substances (NPSs), originating from raw materials that are largely abused. GC-PI/MS allowed us to observe the molecular ions of all of the substances we examined. Some of these compounds showed only the molecular ions in the mass spectra; <i>i.e.</i>, no fragment ions were observed. The mass spectra of other compounds showed fragment ions at varying intensities in addition to the molecular ions. Accordingly, we attempted to determine the cleavage difference between the two spectra of PI/MS and electron ionization/mass spectrometry (EI/MS) theoretically. Moreover, we created a private reference library of the PI/MS spectra using the software NIST14 Mass Spectral Library, installed in the control system; we registered the additional PI/MS spectrum data of the 209 compounds tested. After creating the new PI/MS spectrum library, we measured the NPS samples with GC-EI/MS and GC-PI/MS, which showed that the EI/MS spectrum data are not sufficient to identify any unknown compounds, but can be supported using the new PI/MS reference library. We have demonstrated that GC-PI/MS can be an invaluable technique for providing additional structural information when analyzing NPSs.
分析化学 66(7), 477-486, 2017