Schmidberger Andreas, Durner Bernhard, Gehrmeyer David, Schupfner Robert
Institute for Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Universitätsstraße 31, Regensburg, 93053, Germany.
Federal Agency for Nature Conservation, Konstantinstraße 110, Bonn, 53179, Germany.
Forensic Sci Int. 2018 Aug;289:363-367. doi: 10.1016/j.forsciint.2018.06.016. Epub 2018 Jun 19.
The age determination of elephant ivory provides necessary and crucial information for all criminal prosecution authorities enforcing the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The knowledge of the age of ivory allows to distinguish between pre-convention, hence legal material and ivory deriving from recent, illegal poaching incidents. The commonly applied method to determine the age of ivory is radiocarbon dating in the form of bomb pulse dating, which however will fade out soon. This work provides an enhancement of the radiocarbon dating method by supplementary determination of the isotope profile of 90-Sr and the two thorium isotopes 228-Th and 232-Th. This combined analysis allows for a precise and unambiguous age determination of ivory. We provided calibration curves for all involved radionuclides by analyzing ivory samples with known age and investigated a new method for the extraction of strontium from ivory.
象牙的年龄测定为所有执行《濒危野生动植物种国际贸易公约》的刑事起诉当局提供了必要且关键的信息。了解象牙的年龄有助于区分公约生效前的合法材料与近期非法偷猎事件中获取的象牙。目前常用的象牙年龄测定方法是放射性碳测年法中的核弹脉冲测年法，但这种方法很快就会失效。本研究通过补充测定90-Sr以及两种钍同位素228-Th和232-Th的同位素谱，改进了放射性碳测年法。这种综合分析能够精确且明确地测定象牙的年龄。我们通过分析已知年龄的象牙样本，为所有相关放射性核素提供了校准曲线，并研究了一种从象牙中提取锶的新方法。
