For major element concentrations, the intra-laboratory analytical precision (%RSDr) ranges from 7 to 18%, with higher percentages for Ti and K. The%RSDr are smaller than the inter-laboratory analytical precision (%RSDR; <15–30%). Trace element concentrations vary by 5 orders of magnitude (0.1 mg kg−1 for Th to 10,000 mg kg−1 for Ba). The intra-laboratory analytical precision%RSDr varies between 8 and 45%. The reproducibility values (%RSDR) range from 13 to <50%, although extreme value >100%was found for the high field strength elements (Hf, Th, Zr, Nb). The rare earth element (REE) concentrations, which vary over 3 orders of magnitude, have%RSDr and%RSDR values at 8–15%and 20–32%, respectively. However, the REE patterns (which are very important for paleo-environmental, taphonomic and paleo-oceanographic analyses) are much more consistent.
These data suggest that the complex and unpredictable nature of the mineralogical and chemical composition of fossil bone makes it difficult to set-up and calibrate analytical instruments using conventional standards, and may result in non-spectral matrix effects. We propose an analytical protocol that can be employed in future inter-laboratory studies to produce a certified fossil bone geochemical standard.