ATR-FTIR spectral database for identification of archaeological materials

The chemical analyses of archaeological objects or more broadly of cultural heritage testimonies has developed significantly in the last few decades to become an essential element for studying the nature and origin of materials used by ancient populations; for identifying the transformation of these materials through the preparation or use of utilitarian objects, symbolic items or artworks; and for the establishment of the chronological and environmental framework in which ancient populations lived. These analyses are also an important component for understanding the alteration processes of these materials over time, and for establishing the most appropriate conservation or restoration procedures for cultural or natural history collections.
Among structural and molecular analysis, Fourier transform infrared (FTIR) spectroscopy can be considered as one of the most adapted techniques for the analysis of archaeological or cultural heritage materials. This technique allows the analysis of a wide range of both organic and inorganic components simultaneously (Bitossi, et al. , 2005; Casadio & Toniolo, 2001; Dallongeville, et al. , 2016). FTIR spectroscopy is effective in analysing poorly crystallized or amorphous materials and is therefore highly complementary to X-Ray diffraction (XRD) routinely used for mineralogical identification. However, FTIR spectra can be difficult to interpret due to broad bands that can overlap significantly in mixtures of several compounds. FTIR spectroscopy is also well adapted to microscopic analysis (micro-FTIR), with a spatial resolution that can reach less than 10 µm even using conventional laboratory instruments, enabling the analysis of micro-samples, small inclusions of particles in a heterogeneous matrix, or even micro-chemical imaging (Bitossi…