Department of Chemistry, Federal University of Espírito Santo, Vitória, ES, 29075-910, Brazil.
National Institute of Forensic Science and Technology (INCT Forensics), Vitória, ES, 29075-910, Brazil.
J Forensic Sci. 2020 Nov;65(6):2188-2193. doi: 10.1111/1556-4029.14526. Epub 2020 Aug 10.
The concentrations of lead (Pb), barium (Ba), and antimony (Sb), characteristic of GSR, were determined in soil sediments and immature (larvae) of cadaveric flies of the family Calliphoridae, by inductively coupled plasma mass spectrometry (ICP-MS). This research refers to a case study from two real crime scenes in which the corpses were in an advanced state of decomposition. In case 1, the victim had holes similar to gunshot wounds, and in case 2, there was no evidence of perforations in the corpse. Soil sediment collection was performed at three different points of the terrain, at a minimum distance of 10 m from the corpse, for cases 1 and 2. In relation to the collection of immatures, larvae were collected in regions of the mouth, nose, and orifices similar to the entry of firearms projectile into the body, for case 1, and collection of larvae and pupae, located on the body and underneath it, for case 2. It was possible to detect and quantify the three elements of interest (Pb, Ba, and Sb) by ICP-MS in both sediment and cadaveric larvae. Concentrations of 4.44, 8.74, and 0.08 μg/g were obtained for Pb, Ba, and Sb, respectively, in the soil for case 1. For the case 2, the concentrations in Pb, Ba, and Sb were from 16.34 to 26.02 μg/g; from 32.64 to 57.97 μg/g and from 0.042 to 0.30 μg/g, respectively. In the larvae, Pb, Ba, and Sb were quantified in cases 1 and 2 with a concentration of 6.28 and 1.78 μg/g for Pb, 1.49 and 2.94 μg/g for Ba, 0.50 μg/g and <LD for Sb, respectively. These new results present the detection of characteristic elements of GSR in cadaveric larvae in humans in a real crime scene, besides highlighting the importance of the study of immature flies, using the ICP-MS technique in forensic analysis.
采用电感耦合等离子体质谱法（ICP-MS），测定了土壤沉积物和尸体蝇科幼虫（未成熟）中 GSR 特征的铅（Pb）、钡（Ba）和锑（Sb）浓度。这项研究涉及两个真实犯罪现场的案例研究，尸体处于高度腐烂状态。在案例 1 中，受害者有类似枪伤的孔，而在案例 2 中，尸体上没有穿孔的证据。在距离尸体至少 10 米的地形三个不同点进行了土壤沉积物采集。关于未成熟个体的采集，在尸体入口处的口腔、鼻腔和孔道等区域采集了幼虫，用于案例 1，而在案例 2 中，采集了位于身体及其下方的幼虫和蛹。通过 ICP-MS 可以检测和定量分析沉积物和尸体幼虫中这三种感兴趣的元素（Pb、Ba 和 Sb）。在案例 1 的土壤中，分别获得了 Pb、Ba 和 Sb 的浓度为 4.44、8.74 和 0.08μg/g。对于案例 2，Pb、Ba 和 Sb 的浓度分别为 16.34 至 26.02μg/g、32.64 至 57.97μg/g 和 0.042 至 0.30μg/g。在幼虫中，在案例 1 和 2 中定量了 Pb、Ba 和 Sb，浓度分别为 6.28 和 1.78μg/g 的 Pb、1.49 和 2.94μg/g 的 Ba、0.50μg/g 和 <Sb 的检出限。这些新结果表明，在真实犯罪现场的人类尸体幼虫中检测到了 GSR 的特征元素，同时强调了使用 ICP-MS 技术进行法医分析时，研究未成熟苍蝇的重要性。
