Supplementary information files for differentiation of body fluid stains using a portable, low-cost Ion Mobility Spectrometry device – A pilot study

Supplementary files for article Differentiation of body fluid stains using a portable, low-cost ion mobility spectrometry device—a pilot studyThe identification and recovery of suspected human biofluid evidence can present a bottleneck in the crime scene investigation workflow. Crime Scene Investigators typically deploy one of a number of presumptive enhancement reagents, depending on what they perceive an analyte to be; the selection of this reagent is largely based on the context of suspected evidence and their professional experience. Positively identified samples are then recovered to a forensic laboratory where confirmatory testing is carried out by large lab-based instruments, such as through mass-spectrometry-based techniques. This work proposes a proof-of-concept study into the use of a small, robust and portable ion mobility spectrometry device that can analyse samples in situ, detecting, identifying and discriminating commonly encountered body fluids from interferences. This analysis exploits the detection and identification of characteristic volatile organic compounds generated by gentle heating, at ambient temperature and pressure, and categorises samples using machine learning, providing investigators with instant identification. The device is shown to be capable of producing characteristic mobility spectra using a dual micro disc pump configuration which separates blood and urine from three visually similar interferences using an unsupervised PCA model with no misclassified samples. The device has the potential to reduce the need for potentially contaminating and destructive presumptive tests, and address the bottleneck created by the time-consuming and laborious detection, recovery and analysis workflow currently employed.This dataset describes the analysis of dried biofluid spots using a portable ion mobility mass spectrometer fitted with a thermal desorption probe. It includes blood, urine and visually similar contaminants.

《便携式、低成本离子迁移率质谱仪在体液污渍区分中的应用——一项试点研究》补充文件。疑似人体生物流体证据的识别与提取在犯罪现场调查流程中可能成为瓶颈。现场犯罪调查员通常会根据其判断的检测物类型，部署多种假设性增强试剂之一；此试剂的选择主要基于疑似证据的情境及其专业经验。经确证的样本随后被送至法医实验室，通过大型实验室仪器进行确认性测试，例如通过基于质谱技术的手段。本研究提出了一项概念验证研究，探讨了小型、坚固且便携的离子迁移率质谱仪的使用，该仪器能够在现场分析样本，检测、识别和区分常见的体液干扰。该分析利用了在常温常压下通过温和加热产生的特征挥发性有机化合物的检测和识别，并使用机器学习对样本进行分类，为调查员提供即时识别。该设备通过双微盘泵配置显示出能够产生特征迁移率光谱，利用无监督的PCA模型从三种视觉上相似的干扰中分离血液和尿液，且无误分类样本。该设备有望减少对可能污染和破坏性假设性测试的需求，并解决目前耗时且繁重的检测、提取和分析工作流程所造成的瓶颈。本数据集描述了使用配备热脱附探头的便携式离子迁移率质谱仪对干燥生物流体斑点的分析。它包括血液、尿液和视觉上相似的污染物。