Heat-induced Bone Diagenesis Probed by Vibrational Spectroscopy

• Published in: Scientific reports Vol. 8; no. 1; pp. 15935 - 13
• Main Authors: Marques, M. P. M., Mamede, A. P., Vassalo, A. R., Makhoul, C., Cunha, E., Gonçalves, D., Parker, S. F., Batista de Carvalho, L. A. E.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.10.2018; Nature Publishing Group
• Subjects: 140/133; 631/181/19/27; 639/638; Bone matrix; Burning; Controlled conditions; Diagenesis; Forensic science; Fourier transforms; Heat; Humanities and Social Sciences; Hydroxylation; multidisciplinary; Neutron scattering; Neutrons; Science; Science (multidisciplinary); Spectroscopy; Hydroxyapatite; Bone Diagenesis; Bioapatite; Inelastic Neutron Scattering Spectroscopy; Attenuated Total Reflectance Fourier Transform Infrared (FTIR-ATR)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-34376-w

Complementary vibrational spectroscopic techniques – infrared, Raman and inelastic neutron scattering (INS) – were applied to the study of human bone burned under controlled conditions (400 to 1000 °C). This is an innovative way of tackling bone diagenesis upon burning, aiming at a quantitative evaluation of heat-induced dimensional changes allowing a reliable estimation of pre-burning skeletal dimensions. INS results allowed the concomitant observation of the hydroxyl libration (OH libration ), hydroxyl stretching (ν(OH)) and (OH libration  + ν(OH)) combination modes, leading to an unambiguous assignment of these INS features to bioapatite and confirming hydroxylation of bone’s inorganic matrix. The OH lib , ν(OH) and ν 4 (PO 4 3− ) bands were identified as spectral biomarkers, which displayed clear quantitative relationships with temperature revealing heat-induced changes in bone’s H-bonding pattern during the burning process. These results will enable the routine use of FTIR-ATR (Fourier Transform Infrared-Attenuated Total Reflectance) for the analysis of burned skeletal remains, which will be of the utmost significance in forensic, bioanthropological and archaeological contexts.