A new tool to human provenancing? Neodymium in a forensic and archaeological context.

The addition of another isotope system to the human provenance repertoire can potentially provide us with more specific information on the region of origin of a person, as well as address some of the limitations that are currently still related to the now commonly used isotopic techniques: oxygen (O), hydrogen (H), strontium (Sr) and lead (Pb). This study reports on the viability of using neodymium isotopes (¹⁴³Nd/¹⁴⁴Nd) as a possible tool to track the origins of humans. Nd is a light rare earth element (REE), which is, in contrast to what the name suggests, widely distributed in the Earth’s crust. Due to the isotopic variations in the crust Nd isotopes have previously been successfully applied to identify the production centres of glass archaeological artefacts (Ganio et al. 2013). The tendency of the human body to filter out non-essential elements means that REE concentrations are very low in human teeth (Nd <0.1 ppm), making previous Nd isotope analysis of human tissue impossible. Due to recent developments in mass spectrometry the analysis of Nd has become achievable and results can be used to complement information derived from other isotope systems. We report the optimisation of chromatographic methods to separate Nd from bio-apatite. Sub-nanogram amounts of Nd were analysed using a latest generation thermal ionization mass spectrometer (TRITON-Plus) equipped with 10¹³ Ω resistors at the Vrije Universiteit Amsterdam (Koornneef et al. 2014; 2015). This study presents the neodymium results of third molars from modern Dutch residents. These results will then be compared to O, Sr and Pb data, demonstrating the possibilities for Nd as a new forensic and an archaeological human provenancing tool.