Evaluation of neodymium isotope analysis of human dental enamel as a provenance indicator using 1013 Ω amplifiers (TIMS)

Abstract

Human provenance studies employing isotopic analysis have become an essential tool in forensic and archaeological sciences, with multi-isotope approaches providing more specific location estimates compared to single isotope studies. This study reports on the human provenancing capability of neodymium isotopes ( 143 Nd/ 144 Nd), a relatively conservative tracer in the environment. Neodymium isotope ratios have only recently been determined on human remains due to low concentrations in human dental enamel (ppb range), requiring thermal ionisation mass spectrometry (TIMS) using 10 13 Ω resistors. Dental elements (third molars) from 20 individuals born and raised in the Netherlands were analysed for Nd concentration ( n = 12) and Nd isotope ratios ( n = 15). The geological control on Nd isotope composition was examined using coupled Nd-Sr isotope analysis of the same third molar. Teeth from different geological environments were also analysed (Caribbean, Columbian, and Icelandic, n = 5). Neodymium elemental concentrations in dental elements ranged between 0.1 and 7.9 ppb (median 0.5 ppb). The Dutch 143 Nd/ 144 Nd ratios of the provinces of Limburg and Friesland were between 0.5118 and 0.5121, with Dutch 87 Sr/ 86 Sr ratios in agreement with the previously established local range (0.708–0.710). The current findings were compared to previously published results on Nd concentration and composition from Dutch individuals. The concentration of Nd and 143 Nd/ 144 Nd ratios were weakly correlated (R 2 = 0.47, n = 17) in Dutch human dental enamel. The majority ( n = 25, 83.3%) of individuals had Nd and Sr isotope values isotopically indistinguishable from the geological environment in which their third molars formed and mineralised. However, the Nd isotope ratios of the Icelandic individual and several Dutch individuals ( n = 4) suggested that Nd in enamel is not solely influenced by geological environment. In order for neodymium isotopes to be quantitatively applied in forensic and archaeological settings further analyses of individuals from various geographical regions with well-defined dietary Nd isotope data are required.

Isotopic analysis of sub‐nanogram neodymium loads using new ATONA™ amplifiers

“…The ATONA™ amplifier technology has the potential to provide higher precision results for these types of studies, allowing more nuanced conclusions to be reached about geologic systems with lower age or 143 Nd/ 144 Nd variability. Furthermore, archaeologists are using ultra‐trace 143 Nd/ 144 Nd measurements in dental enamel which contains very little Nd for provenance studies, 34,35 and for “non‐invasive” 143 Nd/ 144 Nd measurements of precious artifacts for which traditional destructive analyses is not a possibility 36 . For archaeologists the ability of ATONA™ amplifiers to precisely measure the isotopic composition of smaller amounts of Nd will allow for analyses of a wider range of artifacts, while still enabling conclusions to be made about the origin of archaeological samples.…”

“…2,3,33 The ATONA™ amplifier technology has the potential to provide higher precision results for these types of studies, allowing more nuanced conclusions to be reached about geologic systems with lower age or 143 Nd/ 144 Nd variability. Furthermore, archaeologists are using ultratrace 143 Nd/ 144 Nd measurements in dental enamel which contains very little Nd for provenance studies, 34,35 and for "non-invasive"…”

Neodymium isotopes in modern human dental enamel: An exploratory dataset for human provenancing

“…The enamel was sampled, chemically processed and analyzed at the Faculty of Science, Vrije Universiteit Amsterdam [ 2 , 11 , 24 ]. Teeth were collected in cleaned 50 mL plastic centrifuge tubes (rinsed >3 times with Milli-Q and 1 time with ethanol (Purity Grade: absolut, CHROMASOLV®, for high-performance liquid Chromatography)).…”

“…This collection presents the neodymium (Nd) and strontium (Sr) isotope results from modern human dental elements (third molars) of 47 individuals born and raised in the Netherlands, Grenada, Curaçao, Bonaire, Columbia and Iceland [2] ( Table 1 ). Neodymium isotope composition was successfully analyzed for 40 individuals (ranging between 143 Nd/ 144 Nd = 0.511820 to 0.512773) ( Fig.…”

“…For a more detailed comparison and interpretation of these background and human isotopic ranges, please see Plomp et al. [2] .…”