Kranenburg Ruben F, Lukken Chris K, Schoenmakers Peter J, van Asten Arian C
Dutch National Police, Unit Amsterdam, Forensic Laboratory, Kabelweg 25, Amsterdam 1014 BA, the Netherlands; Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94157, Amsterdam 1090 GD, the Netherlands.
Dutch National Police, Unit Amsterdam, Forensic Laboratory, Kabelweg 25, Amsterdam 1014 BA, the Netherlands; Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94157, Amsterdam 1090 GD, the Netherlands.
J Chromatogr B Analyt Technol Biomed Life Sci. 2021 Mar 29;1173:122675. doi: 10.1016/j.jchromb.2021.122675.
Analysis of isomeric mixtures is a significant analytical challenge. In the forensic field, for example, over 1000 new psychoactive substances (NPSs), comprising of many closely related and often isomeric varieties, entered the drugs-of-abuse market within the last decade. Unambiguous identification of the isomeric form requires advanced spectroscopic techniques, such as GC-Vacuum Ultraviolet Spectroscopy (GC-VUV). The continuous development of NPSs makes the appearance of a novel compound in case samples a realistic scenario. While several analytical solutions have been presented recently to confidently distinguish NPS isomers, the presence of multiple isomers in a single drug sample is typically not considered. Due to their structural similarities it is possible that a novel NPS coelutes with a known isomer and thus remains undetected. This study investigates the capabilities of VUV spectral deconvolution for peak detection and identification in incompletely resolved drug mixtures. To mimic worst case scenarios, severe coelution was deliberately induced at elevated GC temperatures. The deconvolution software was nevertheless able to correctly detect both substances, even in case of near-identical VUV spectra at almost full coelution. As a next step, spectra were subsequently removed from the reference library to simulate the scenario in which a novel substance was encountered for the first time in forensic case work. However, also in this situation the deconvolution software still detected the coelution. This work shows that a VUV library match score below 0.998 may serve as a warning that a novel substance may be present in a street sample.
异构体混合物的分析是一项重大的分析挑战。例如，在法医领域，过去十年中有1000多种新型精神活性物质（NPS）进入了滥用药物市场，其中包括许多密切相关且通常为异构体的品种。异构体形式的明确鉴定需要先进的光谱技术，如气相色谱 - 真空紫外光谱法（GC - VUV）。NPS的不断发展使得案件样本中出现新型化合物成为一种现实情况。虽然最近已经提出了几种分析解决方案来可靠地区分NPS异构体，但单个药物样本中存在多种异构体的情况通常未被考虑。由于它们的结构相似性，新型NPS有可能与已知异构体共洗脱，从而未被检测到。本研究调查了VUV光谱去卷积在不完全分离的药物混合物中进行峰检测和鉴定的能力。为了模拟最坏的情况，在升高的GC温度下故意诱导严重的共洗脱。然而，即使在几乎完全共洗脱且VUV光谱几乎相同的情况下，去卷积软件仍能够正确检测到两种物质。下一步，从参考库中删除光谱以模拟法医案件工作中首次遇到新型物质的情况。然而，在这种情况下，去卷积软件仍然检测到了共洗脱。这项工作表明，VUV库匹配分数低于0.998可能作为一种警示，表明街头样本中可能存在新型物质。
