Study of the formation of metal oxalates and soaps in oil paintings from the Southern Netherlands using ToF-SIMS

This work consists of applying the SIMS technique to the analysis of works of art with the aim of their restoration or conservation, as a complementary method to the ones already used. Indeed, this master thesis is carried out in collaboration with IRPA as part of an international project called Metox, which studies the formation of metal oxalates and soaps in oil paintings by Flemish primitive painters from the XV-XVIIth centuries. IRPA has already been able to achieve numerous analyses using several methods, and this thesis will attempt to confirm the results obtained and discover new ones. The studies were not carried out directly on real samples but were much more progressive. Initially, the SIMS analysis focused only on pure powders, synthesised in the laboratory, chemical elements that would be sought in the final analyses. In order to obtain a signature of this elements and to be able to identify them during the analysis of the more complex original samples and to be able to interpret the results obtained with the original sections. A pure linseed oil sample was also analysed for the same purpose as the analysis of pure powders, i.e. in order to facilitate its identification in more complexe samples thanks to its specific "fingerprint" spectrum. After that, the analyses focused samples mixing oil with all the pure compounds previously analysed. This allowed us to highlight the distribution of the different compounds within the sample and therefore to develop an optimal analysis technique. This consisted of determining an 'optimal' depth where we could observe the most compounds that our work focuses on and then etching down to image the surface at that depth. Finally, by analysing real samples, it was possible to confirm certain results obtained by IRPA. But we also obtain some disappointing results, as it was the case for the the previous samples, pointing to potential causes such as the matrix effect, probability of ionisation and detection limit for certain elements, sample preparation, sample processing,... Some perspectives, among the many imaginable in this vast and exciting field of research, were also put forward to close this master thesis.