Mesihää Samuel, Ketola Raimo A, Pelander Anna, Rasanen Ilpo, Ojanperä Ilkka
Department of Forensic Medicine, University of Helsinki, PO Box 40, Kytösuontie 11, 00014, Helsinki, Finland.
Forensic Toxicology Unit, National Institute for Health and Welfare, PO Box 30, 00271, Helsinki, Finland.
Anal Bioanal Chem. 2017 Mar;409(8):2007-2013. doi: 10.1007/s00216-016-0148-y. Epub 2016 Dec 22.
Gas chromatography coupled to atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry (GC-APCI-QTOFMS) was evaluated for the identification of new psychoactive substances (NPS). An in-house high mass resolution GC-APCI-QTOFMS test library was developed for 29 nitrogen-containing drugs belonging mostly to synthetic stimulants. The library was based on 12 intra-day measurements of each compound at three different collision energies, 10, 20 and 40 eV. The in-house library mass spectra were compared to mass spectra from a commercial library constructed by liquid chromatography-electrospray ionization (LC-ESI) QTOFMS. The reversed library search scores between the in-house GC-APCI library and the commercial LC-ESI library were compared once a week during a 5-week period by using data measured by GC-APCI-QTOFMS. The protonated molecule was found for all drugs in the full scan mode, and the drugs were successfully identified by both libraries in the targeted MS/MS mode. The GC-APCI library score averaged over all collision energies was as high as 94.4/100 with a high repeatability, while the LC-ESI library score was also high (89.7/100) with a repeatability only slightly worse. These results highlight the merits of GC-APCI-QTOFMS in the analysis of NPS even in situations where the reference standards are not immediately available, taking advantage of the accurate mass measurement of the protonated molecule and product ions, and comparison to existing soft-ionization mass spectral libraries. Graphical abstract Tandem mass spectra obtained from GC-APCI-QTOFMS are comparable to LC-ESI-QTOFMS library spectra.
采用气相色谱-大气压化学电离四极杆飞行时间质谱联用技术（GC-APCI-QTOFMS）对新型精神活性物质（NPS）进行鉴定。针对29种主要属于合成兴奋剂的含氮药物，建立了一个内部高质量分辨率GC-APCI-QTOFMS测试库。该库基于每种化合物在10、20和40 eV三种不同碰撞能量下的12次日内测量数据。将内部库质谱与通过液相色谱-电喷雾电离（LC-ESI）QTOFMS构建的商业库质谱进行比较。在为期5周的时间里，每周使用GC-APCI-QTOFMS测量的数据，比较一次内部GC-APCI库与商业LC-ESI库之间的反向库搜索分数。在全扫描模式下，所有药物均检测到质子化分子，并且在靶向MS/MS模式下，两个库均成功鉴定出这些药物。所有碰撞能量下GC-APCI库分数的平均值高达94.4/100，具有高重复性，而LC-ESI库分数也很高（89.7/100），重复性仅略差。这些结果突出了GC-APCI-QTOFMS在NPS分析中的优点，即使在没有立即获得参考标准品的情况下，也能利用质子化分子和产物离子的精确质量测量，并与现有的软电离质谱库进行比较。图形摘要：从GC-APCI-QTOFMS获得的串联质谱与LC-ESI-QTOFMS库质谱具有可比性。
