Non-destructive, portable approach as pre-screening tool for archaeological burnt bones

Ancient bones are archives of information to reconstruct past life. However, detecting the organic content and the crystallinity changes of bone apatite post-mortem alteration becomes more challenging when burial conditions are coupled with thermal degradation. The present study proposed a non-invasive pre-screening method to distinguish burnt bones based on diagnostic spectral features, using a reflectance portable FT-IR spectrometer (650–5500 cm−1) and a portable miniaturized near-infrared (MicroNIR) spectrometer (900–1700 nm). Burnt bones from the Roman age (Modena, Italy) were analyzed and the pre-screening approach was combined with a multivariate data analysis. Principal Component Analysis (PCA) was used to enhance spectral changes leading to a differentiation among the specimens, according to their chemical changes. The proposed methodology highlighted the potential of the two non-destructive and portable instruments, and of chemometric analysis to select the most suitable samples for forensic and archaeological studies, overcoming drawbacks related to the traditionally applied visual examination of bones colour.