Seeking for the correlation between the Chemometric Indices of ATR-FTIR Spectroscopy and Multidetector CT obtained Density on Bones Exposed to Heat

Abstract

Abstract Charred and burned human and animal skeletal remains are frequently found in archaeological records or can be a subject of forensic investigation. As exposure to heat causes specific changes to the physical and chemical characteristics of the remains, it presents a powerful source for a better understanding of the taphonomic history of the remains. FTIR spectroscopy is a commonly used technique when trying to understand these changes and through them the taphonomic history of the remains. Recently, density calculated from CT scans is also incorporated into this type of study. The main objective of here presented research is to establish a correlation between the chemometric indices obtained with ATR-FTIR spectroscopy and density obtained with Multidetector CT. To the best of our knowledge, the correlation between the two was never explored before. For this purpose, the midsection of defleshed bovine femur diaphyses were exposed to different temperatures for various time spans and analysed with ATR-FTIR spectroscopy and Multidetector CT. ATR-FTIR obtained results, namely the changes in the organic and mineral bone components, agree with previous studies and provide a baseline for understanding the changes in the density. The latter decreases and increases depending on the loss of organic matter, crystallization, cyanamides and hydroxyl groups incorporation into the mineral lattice, and ordering of the lattice. Additionally, significant differences were observed in the changes caused due to short- or long-term exposure to heat. With some additional work, even machine learning algorithms could be applied to the samples with an unknown taphonomic history to better understand the time and temperatures of their exposure. Furthermore, this type of research also provides important data for planning non-destructive analyses of ancient remains.