Abstract：
Chemical attribution is a vital tool to attribute chemicals or related materials to their origins in chemical forensics via various chemometric methods. Current progress related to organophosphorus nerve agents (OPNAs) has mainly focused on the attribution of chemical sources and synthetic pathways. It has not yet been applied in matching exposed biological samples to their sources. This work used chemical attribution to explore organic impurity profiles in biological samples exposed to various OPNAs. Chemical attribution was first used to identify the exposure source of biological samples based on the full-scan data via comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometer (GC × GC-TOFMS). Taking peak area as the only variable, it can quickly match exposed samples to their sources by applying unsupervised or supervised models, screen difference compounds via one-way ANOVA or t-tests, and then identify valuable impurities that can distinguish different types of exposed samples. To further obtain the impurity profile only applicable to a certain weapon\' samples, the irrelevant components were removed via conventional methods. The findings showed there were 53 impurities that can promote distinguishing six groups of OPNA exposed samples, as well as 42 components that can be used as valuable impurities to distinguish class G and class V samples. These were all unique impurities that appear in a certain weapon\' samples. The outcomes can be a reference for tracing the source for OPNA-exposed samples, which was beneficial to the further development in source matching of forensic samples. Moreover, the chemical attribution for impurity profiles in biological samples after weapons exposure may inspire research into the characteristics of impurity profile in biological samples as well as practical applications of chemical attribution for OPNA-exposed samples, that may expand potential biomarkers and break the limits of existing markers in the future.
摘要：
化学归因是通过各种化学计量学方法将化学品或相关材料归因于其来源的重要工具。目前与有机磷神经毒剂（OPNAs）有关的进展主要集中在化学来源和合成途径的归属上。它尚未用于将暴露的生物样品与其来源相匹配。这项工作使用化学属性来探索暴露于各种OPNA的生物样品中的有机杂质谱。首先通过全面的二维气相色谱-飞行时间质谱仪（GC×GC-TOFMS），根据全扫描数据，使用化学归因来识别生物样品的暴露源。以峰面积为唯一变量，它可以通过应用无监督或监督模型来快速将暴露的样本与其来源匹配，通过单向方差分析或t检验筛选差异化合物，然后识别有价值的杂质，可以区分不同类型的暴露样品。为了进一步获得仅适用于特定武器样品的杂质分布图，通过常规方法去除无关成分。研究结果表明，有53种杂质可以促进区分六组OPNA暴露样品，以及可用作有价值的杂质以区分G类和V类样品的42种组分。这些都是某种武器样品中出现的独特杂质。结果可以作为追踪OPNA暴露样本来源的参考，有利于法医样本来源匹配的进一步发展。此外，武器暴露后生物样品中杂质谱的化学归属可能会激发对生物样品中杂质谱特征以及OPNA暴露样品化学归属的实际应用的研究，这可能会扩大潜在的生物标志物，并在未来打破现有标志物的限制。
