Testing LA-ICP-MS analysis of archaeological bones with different diagenetic histories for paleodiet prospect

Abstract

LA-ICP-MS is a powerful technique requiring minimal sample preparation and providing high spatial resolution which may offer the possibility of analysing trace elements in targeted pristine areas of archaeological bone sections. This would provide invaluable information about an individual's life if combined with the geochemical composition of the teeth from the same individual. However, there is no consensus regarding the calibration to be used for LA-ICP-MS analysis of bone, which is a highly complex organo-mineral tissue. In this study, we tested different calibration approaches (NIST and USGS glass series, synthetic phosphate glass and synthetic phosphate pellet from USGS) on a modern bone. The best method was applied to three Precolumbian skeletons (Lerma Valley, Mexico). These individuals show different degrees of preservation (crystallinity, calcite, F and organic matter content) which have been previously explored at the intra-skeletal level. A bone sample with exceptional preservation from the Dogon Country (Mali) was analysed for comparison. Based on BSE SEM images and element distribution of the bone sections obtained via LA-ICP-MS mapping, quantification of Ca, P, Li, Zn, V, U, Na, Mg, Sr and Ba was performed using LA-ICP-MS spot analysis on areas displaying varying concentration profiles and histological preservation. Although avoiding sampling at the external margin of the bone sections may minimize diagenetic Li, Zn, V, U, Sr and Ba, it was not possible to discriminate biological from diagenetic Sr adsorbed onto the bone crystallites of the best preserved Precolumbian skeleton, whose low crystallinity favored adsorption efficiency. In contrast, the well preserved Dogon sample, as well as the most altered Precolumbian skeletons provided Sr and Ba content roughly similar to concentrations obtained using bulk analysis. LA-ICP-MS can therefore not substitute solution analysis for paleodiet prospect, especially for bones in relatively early state of diagenetic transformations. enamel is less susceptible to diagenetic alteration than bone mineral (Hollund et al., 2013), because of its lower amount of organic material and higher crystallinity (LeGeros, 1991; Kohn et al., 1999), making it a more suitable material for dietary and mobility interpretation from isotopic data (Price et al., 2002). Bone mineral (bioapatite) also archives the dietary habits of individuals but, up to date, there is no perfect proxy for assessing the complete integrity of its geochemical composition. Some pre-treatments are usually applied for leaching diagenetic contaminants (Sillen, 1986), such as calcite, whose presence impacts bone biological δ 13 C and δ 18 O values (Balter et al., 2002). Another way to overcome the diagenetic problem is to use a combination of analytical techniques i.e. XRD (X-Ray Diffraction) and FTIR (Fourier-transform infrared spectroscopy), to assess the preservation of the biological signal registered in the mineral

Comparison of trace element chemistry in human bones interred in two private chapels attached to Franciscan friaries in Italy and Denmark: an investigation of social stratification in two medieval and post-medieval societies

“…The first was the realization that there did not exist a linear translation from the Sr-concentration in foodstuff to the Sr-concentration in human bones [19]. The second was the realization that diagenesis could affect the Sr and Ba concentrations [16,[20][21][22][23][24][25][26]. Lately, it has been argued that even though Sr is classified as a non-essential element, its distribution in the human body could be tied to elements regulated by metabolic processes such as Zn.…”

Bone diagenesis in the marine environment‐I: Characterization and distribution of trace elements in terrestrial mammalian bones recovered from historic shipwrecks

“…are available for the concentrations of Li, U, and Rb in modern sheep bone, although similarly low values are reported for Li (0.50-0.79 ppm, average) and U (0.01 ppm, average) in modern juvenile cow bone(Maurer et al, 2019).The concentrations of Li, Cr, Cu, U, and Rb in the TZ were low (Table2) with Cr content below the LOD. In contrast, Ba and Sr are T A B L E 3…”

“…Both TZ, the mechanically defleshed modern sheep bone, and the underwater archaeological bones were rinsed in MilliQ ® water (Merck KGaA, Darmstadt, Germany) before sampling, which took place respecting the anti-contamination procedures commonly described in literature and found in most cited references (e.g., Castro et al, 2009;Maurer et al, 2019). Jochum et al (2005).…”

Correlation of μXRF and LA-ICP-MS in the analysis of a human bone-cartilage sample

“…Papers on quantitative imaging with use of LA-ICP-MS exist, albeit limited to archaeological objects. 32,33 Quantitative elemental analysis of bone will be of interest for the diagnostic reasons, for example, investigation of Sr incorporation from strontium ranelate with implications for the quality of the mineral crystal; 34 quantication of trace element accumulations (Zn) in the tumorous tissue 3 or estimation of metal transfer from orthopaedic implants. 35 We have recently reported accumulations of elements-xenobiotics, e.g.…”