Spectral Characterisation of Ancient Wooden Artefacts with the Use of Traditional IR Techniques and ATR Device: A Methodological Approach

This work presents a methodological approach to the study of ancient wooden artefacts using FT-IR techniques. Sampling is one of the most important steps during investigation of works of art. However, samples should be taken only when this operation does not appreciably modify any part, or change the integrity of the wooden artefact inquestion. Although it was invasive, a low-destructive method of sampling was used on wood meal in order to obtain reproducible results. Moreover, two modes of operation were compared, namely the transmission mode (carried out on pellets of wood meal mixed with KBr) and the Attenuated Total Reflectance (ATR) mode (carried outdirectly on wood meal). For the former, the effect of the concentration of wood in KBr was also considered. The results show a similar quality of spectra, although a different sensitivity between the two techniques in some spectral ranges was observed. The final focus of this research will be on validating the use of IR spectra to date wooden materials.