Ishimi Akane, Nakanishi Toshio, Seto Yasuo, Nishiwaki Yoshinori
Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan.
RIKEN, SPring-8 Center, Forensic Science Group, Sayo-gun, Japan.
J Forensic Sci. 2022 Sep;67(5):1825-1835. doi: 10.1111/1556-4029.15099. Epub 2022 Jul 19.
Automotive glasses are important forensic evidence often recovered from crime scenes. Black ceramic prints on automotive glasses contains various elements in high concentrations. A portable X-ray fluorescence spectrometer (pXRF) allows an instant and nondestructive analysis of various elements. In this study, the Bruker Tracer 5 g was used as the pXRF equipment. The NIST SRM612 glass standard was used to determine the limit of detection (LODs) of a pXRF and its optimal conditions. The acceleration voltages of 15, 30, and 50 kV were appropriate for measuring Si K (1.740 keV)-Ni K (7.473 keV), Cu K (8.042 keV)-Pb L (10.552 keV), and after Bi K (10.839 keV), respectively. The pXRF was used to compare 37 black ceramic prints on automotive glasses from the known source. The samples were divided into two groups: the Pb type and the Bi type. The samples were compared in pairs. The most appropriate and effective indicators for discriminating between the Pb and Bi type of black ceramic prints on automotive glasses were Zr K /Pb L and Cu K /Cr K for the Pb type, and Zr K /Bi L and Cu K /Cr for the Bi type, respectively. The samples were compared with other elements detected by pXRF to further discriminate them. 98.9% of all pairs were successfully discriminated. Results showed that black ceramic prints on automotive glasses are able to be discriminated by pXRF.
汽车玻璃是经常从犯罪现场获取的重要法医证据。汽车玻璃上的黑色陶瓷印记含有高浓度的各种元素。便携式X射线荧光光谱仪（pXRF）可对各种元素进行即时无损分析。在本研究中，使用布鲁克Tracer 5 g作为pXRF设备。使用NIST SRM612玻璃标准来确定pXRF的检测限（LOD）及其最佳条件。15、30和50 kV的加速电压分别适用于测量Si K（1.740 keV）-Ni K（7.473 keV）、Cu K（8.042 keV）-Pb L（10.552 keV）以及Bi K（10.839 keV）之后的元素。pXRF用于比较来自已知来源的37个汽车玻璃上的黑色陶瓷印记。样品分为两组：Pb型和Bi型。对样品进行两两比较。区分汽车玻璃上Pb型和Bi型黑色陶瓷印记的最合适和有效的指标分别是：Pb型为Zr K /Pb L和Cu K /Cr K，Bi型为Zr K /Bi L和Cu K /Cr。将样品与pXRF检测到的其他元素进行比较以进一步区分它们。所有配对中有98.9%成功区分。结果表明，汽车玻璃上的黑色陶瓷印记能够通过pXRF进行区分。
