Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
Forensic Sci Int. 2010 Feb 25;195(1-3):17-27. doi: 10.1016/j.forsciint.2009.10.029. Epub 2009 Nov 25.
Human bone and teeth fragments can be useful evidence when found in crime scenes and/or mass burials sites. The elemental and isotopic composition of these samples can provide information about environmental exposure events and could also be used to distinguish different individuals. The development and application of robust analytical methods for the quantification of trace elements in these biological matrices may lead to a better understanding of the potential utility of these measurements in forensic analyses. In this paper, we demonstrate the possibility of conducting quantitative analysis of trace metals found in bone remains and suggest a strategy to discriminate between individuals, based on this information. A LA-ICP-SF-MS method using non-matrix matched standard calibration was developed and optimized with bone standard reference materials (SRMs) and subsequently applied to the analysis of real samples. The developed method requires micrograms amount of sample (vs. milligrams required for solution-based analysis) while also reducing the analysis time and resulting in good accuracy (typically <10% bias) and precision (<15% RSD). Additionally, laser ablation allowed using spatial resolution analysis to assess the biogenic elemental composition in buried bone samples. Elemental analysis of bone samples from 12 different individuals provided better discrimination between the individuals when the femur and humerus bones were considered separately (42.7% correct classification with all bones vs. 75.2% and 63.1% for femur bones and humerus bones, respectively). Separation of individuals was achieved by elemental composition of whole teeth samples from 14 individuals, except one case where not all the teeth from the same individual were associated together. Separation of individuals was improved when using elemental composition of the enamel and dentine+cementum layers separately in a set of samples from 7 individuals. These are promising results for the use of elemental analysis by laser ablation ICP-MS for discrimination purposes.
在犯罪现场和/或大规模埋葬地点发现的人类骨骼和牙齿碎片可以作为有用的证据。这些样本的元素和同位素组成可以提供有关环境暴露事件的信息，也可用于区分不同个体。开发和应用稳健的分析方法来定量分析这些生物基质中的微量元素，可能有助于更好地理解这些测量值在法医分析中的潜在用途。本文展示了对骨骼残留中痕量金属进行定量分析的可能性，并提出了一种基于该信息来区分个体的策略。开发了一种使用非基体匹配标准校准的 LA-ICP-SF-MS 方法，并使用骨骼标准参考物质（SRM）进行了优化，随后将其应用于实际样品的分析。该方法需要微克级的样品量（而基于溶液的分析需要毫克级的样品量），同时还缩短了分析时间，并具有良好的准确度（通常<10%的偏差）和精密度（<15%的 RSD）。此外，激光烧蚀允许使用空间分辨率分析来评估埋藏骨骼样品中的生物元素组成。对 12 个不同个体的骨骼样本进行元素分析，当分别考虑股骨和肱骨时，个体之间的区分效果更好（所有骨骼的正确分类率为 42.7%，股骨和肱骨的正确分类率分别为 75.2%和 63.1%）。从 14 个个体的全牙样本的元素组成可以分离个体，但有一个个体的所有牙齿没有关联。从 7 个个体的一组样本中，分别使用牙釉质和牙本质+牙骨质层的元素组成进行分离时，个体的分离效果得到了改善。这些结果为使用激光烧蚀 ICP-MS 进行元素分析以进行鉴别目的提供了有希望的结果。
