On site identification of body fluids through mass spectrometry

内政部应用科学和技术中心(CAST)最近指出，现场鉴定犯罪现场的体液是一项关键的当务之急，被评为“高度优先”。这反映了这样一个事实，即人们越来越倾向于最大限度地实现可在现场进行的分析(而不是将展品转移到实验室环境中，或在此之前)，并以不涉及过度化学污染(例如，使用可以分析血液的喷雾试剂)或专业操作员专业知识的方式进行分析。虽然目前最先进的成像技术可以识别六种关键体液中的一种潜在存在，但从业者仍然无法快速确定这种体液的确切性质。该项目将涉及开发新的环境电离质谱仪方法，应用于犯罪现场的体液。质谱学有可能从犯罪现场的生物流体中阐明额外的化学信息，从而有助于法医调查。博士生的角色将包括开发和修改质谱计离子源，以便能够使用商用便携式质谱仪从一系列不同表面的不同生物流体中检测挥发性有机化合物(VOC)。将使用热解吸法从表面提取挥发性化合物，然后可以对这些方法进行探索，以确定关键的目标代谢物，这些代谢物可以提供信息，还可以接受主成分分析等多元数据分析技术。使用Tese方法将查看生物流体的挥发性指纹。然后，学生将探索从生物体液中获得的VOC图谱是否可以用来识别额外的信息，即嫌疑人的性别或年龄。

The Home Office Centre for Applied Science and Technology (CAST), have recently noted that the on-site identification of body fluids at a crime scene is a key imperative, rated "High Priority". This reflects the fact that there is a growing move towards maximising the analysis that can be performed at a scene (instead of, or prior to, transfer of exhibits to a lab setting) and doing so in ways that do not involve excessive chemical contamination (e.g. with the spray reagents that can elucidate blood) or specialist operator expertise. While the current state of the art imaging technologies can identify the potential presence of one of the six key body fluids, rapid determination of the exact nature of that fluid still eludes practitioners.This project will involve developing new ambient ionisation mass spectrometry approaches to apply to body fluids at crime scenes. Mass spectrometry has the potential to elucidate additional chemical information from biofluids at a crime scene and so aid in the forensic investigation. The PhD students role will involve developing and modifying mass spectrometer ion sources to enable the detection of volatile organic compounds (VOC) from different biofluids from a range of different surfaces using a commercial transportable mass spectrometer. Thermal desorption approaches will be used to extract volatile compounds from the surfaces and these can then be probed to identify key target metabolites that can yield information and also subjected to multivariate data analysis techniques such as principle component analysis. Using tese approaches will look at the volatilomic fingerprint of the biofluid. The student will then explore whether the VOC profiles obtained from biofluids can be used to discern additional information i.e. the sex or age of the suspect.