Variations in Atomic Disorder in Biogenic Carbonate Hydroxyapatite Using the Infrared Spectrum Grinding Curve Method

Abstract

Biogenic carbonate hydroxyapatite crystals are inherently disordered at the atomic level due mainly to the substitutions of various ions in the crystal structure, and, in the case of the bone family of materials, to the fact that these very small crystals have a very large surface‐to‐bulk ratio. Characterization of the extent of disorder is of much interest, as this relates to the stability and hence solubility of the crystals. Here the infrared spectrometry grinding curve approach developed for calcite, is adapted to carbonate hydroxyapatites. The infrared splitting factor is plotted against the full width at half height of the strong phosphate absorption peak as a function of increased grinding of the sample. By doing so, the contribution of particle size to the shape of the peaks is better separated from the contribution of atomic disorder to peak shape. It is shown that differences in disorder exist between dentine, cementum, and bone crystals which could reflect crystal size and/or atomic defects within the crystal. It is als shown that systematic differences exist between enamel samples from different taxa, which we assume only reflects atomic disorder differences within these large crystals. The method can be used to characterize atomic disorder in natural hydroxyapatites, as well as in the many different types of synthetic hydroxyapatites used for biomedical implants.

Variability in the marine radiocarbon reservoir effect in Muscat (Sultanate of Oman) during the 4th millennium BC: reflection of taphonomy or environment?

“…A more rapid degradation of collagen will facilitate further exchange between soil carbonate and bioapatite. Furthermore, recent infrared spectroscopic evidence showed that there were differences in crystallinity among different mammal species (Asscher et al, 2011). Although Asscher et al (2011) did not sample fish or turtle bone, they found that human enamel was more crystalline than any other mammal tested.…”

“…Furthermore, recent infrared spectroscopic evidence showed that there were differences in crystallinity among different mammal species (Asscher et al, 2011). Although Asscher et al (2011) did not sample fish or turtle bone, they found that human enamel was more crystalline than any other mammal tested. A lower crystallinity implies that apatite is more likely to either exchange carbonate with carbonate present in the environment of the grave, or dissolve and re-precipitate new apatite containing exogenous carbonate.…”

Geoarchaeological Investigation of Site Formation and Depositional Environments at the Middle Palaeolithic Open-Air Site of ‘Ein Qashish, Israel

“…The prevalence of Fe-Mn oxides and absence of pyrolized collagen in dark-coloured bones indicate that bone colouration is due to post-depositional staining rather than burning (Nir 2016). Calculated values of the infrared bone crystallinity index (IRSF; Weiner and Bar-Yosef 1990) were plotted in reference to the full width at half maximum of the hydroxylapatite main absorbance band at 1030 cm −1 , following Asscher et al (2011) (Fig. 10).…”

Microarqueología aplicada al análisis e interpretación de termoalteraciones en restos óseos de tortugas de sitios arqueológicos en el caribe colombiano

“…Globalmente hay un amplio conjunto de trabajos sobre microscopía aplicada al análisis de las termoalteraciones (Nicholson 1993, Koon et al 2003, Koon et al 2010Lebon et al 2008, Weiner 2010, Asscher y Boaretto 2011, Nevin et. al.…”

“…Cuando se graficaron los valores SF y FWHH, fue posible generar líneas de tendencia que reflejaron el efecto del tamaño de la partícula. Adicionalmente, con la ubicación en la gráfica del FWHH y el SF, fue posible evidenciar los efectos de desorden atómico (Asscher et al 2011).…”