On the basis of chemical research results, discussion on the painting technique will be provided.*
Binding media determination techniques (gebruikte bindmiddelanalyse technieken)
To determine the binding media used by the painters as well as to identify the restoration products used in recent restoration campaings Pyrolysis- Gas Chromatography/Mass Spectrometry (Py-GC/MS) and Gas Chromatography/Mass Spectrometry (GC/MS) were applied for the characterization of the organic materials present in several samples from the wall painting of Saint Christophorus in de Grote Kerk (Breda, Netherlands).
Analysis before and after cleaning of the surface (analyse voor en na reinigingsbehandeling)
To achieve the purpose, analysis were performed on samples taken before and after the cleaning of the wall painting surface. After the cleaning, samples were selected avoiding contamination from the overpaintings, restoration products, adhesives and cleaning systems used. Moreover, the analysis of micro sub-samples containing single layers enabled the determination of the composition of the sample build-up: a fundamental information to determine the painting technique used. The paper presents an overview of the results obtained from the characterisation of the organic materials present before and after the cleaning. In both cases, the presence of several organic materials in the samples has been detected: Figure 1 is an example of the complexity of materials found in some samples.
Figure 1. a) Stereomicroscope image of a green sample after cleaning; b) cross-section of the green sample; c) SEM image of the cross-section of the sample; d) PCA score plot of the amino acid fraction of he samples analysed after cleaning; e) TIC chromatogram of the lipid resinous fraction of one of the samples before cleaning.
* This is an abstract of the presentation at the Joint Meeting in Breda in october (http://wp.me/pLSqf-16H) of research by Maria Perla Colombini, Anna Lluveras-Tenorio, Anna Laura Restivo of Laboratory of Chemical Science for Safeguarding the Cultural Heritage, Department of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy, firstname.lastname@example.org