Direct Raman Spectroscopy for the Study of Organic Materials (artists’ colorants and organic minerals)

Raman spectroscopy is a well appreciated molecular technique to identify both, organic and inorganic components. While the technique seems to be frequently used for the investigation of inorganic components, organic molecules often pose more challenges during their investigation. Indeed, fluorescence emission, low Raman scattering efficiency and similar molecular structures (hence similar molecular spectra) seem to hinder broad application. Moreover, if these challenges are combined with constrains inherently linked to using mobile Raman instruments, the study of organics is even more hampered. This project aims to develop the tools for to characterize organic molecules via mobile Raman spectroscopy. The research will focus on organic compounds such as 20th and 21st century synthetic organic pigments and colorants, and organic minerals. This way, two major research domains in which mobile Raman spectroscopy is essential are involved, namely archaeometry and geology. Different approaches for the analysis of organic molecules with mobile Raman spectroscopy will be examined. This involves Raman mapping experiments to take advantage of the good spatial distribution of Raman spectroscopy and microspatially offset Raman spectroscopy (µSORS) for the analysis of organic layers. Different data treatment procedures will be developed and the findings will be applied in case studies.