Surrey Ion Beam Centre, University of Surrey, GU2 7XH, UK.
Analyst. 2013 Aug 21;138(16):4649-55. doi: 10.1039/c3an00597f. Epub 2013 Jun 18.
Imaging and analyzing gunshot residue (GSR) particles using the scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDS) is a standard technique that can provide important forensic evidence, but the discrimination power of this technique is limited due to low sensitivity to trace elements and difficulties in obtaining quantitative results from small particles. A new, faster method using a scanning proton microbeam and Particle Induced X-ray Emission (μ-PIXE), together with Elastic Backscattering Spectrometry (EBS) is presented for the non-destructive, quantitative analysis of the elemental composition of single GSR particles. In this study, the GSR particles were all Pb, Ba, Sb. The precision of the method is assessed. The grouping behaviour of different makes of ammunition is determined using multivariate analysis. The protocol correctly groups the cartridges studied here, with a confidence >99%, irrespective of the firearm or population of particles selected.
使用配备能量色散 X 射线光谱仪（SEM-EDS）的扫描电子显微镜对射击残留物（GSR）颗粒进行成像和分析是一种标准技术，可提供重要的法医学证据，但由于对微量元素的灵敏度低以及难以从小颗粒获得定量结果，该技术的分辨力有限。本文提出了一种新的、更快的方法，使用扫描质子微束和粒子感生 X 射线发射（μ-PIXE），以及弹性背散射谱法（EBS），用于无损、定量分析单个 GSR 颗粒的元素组成。在这项研究中，GSR 颗粒均为 Pb、Ba、Sb。评估了该方法的精度。使用多元分析确定了不同弹药制造商的分组行为。该方案可正确分组，置信度>99%，与所选择的枪支或颗粒群体无关。
