Elemental identification of blue paintings traces present in historic cemeteries in the São Martinho region, southern Brazil

• Published in: Journal of molecular structure 2018-03, Vol.1155, p.434-442
• Main Authors: Costa, Thiago G., Richter, Fábio Andreas, Castro, Elisiana Trilha, Gonçalves, Samantha, Spudeit, Daniel A., Micke, Gustavo A.
• Format: Article
• Language: English
• Subjects: Architectural aspects; Chromatography; Conservation science; Funerary heritage; Spectroscopy
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2017.11.027

Cemeteries are of great significance in many communities, often being considered of invaluable historical, artistic, architectural and cultural significance and thus they need to be preserved. In this regard, understanding the historical aspects and the construction techniques used is essential for their protection. The purpose of this paper is to describe historical aspects of the funerary heritage present in the region of São Martinho in southern Brazil, along with an analysis of the blue paint found in cemeteries of German colonies in the region studied. FTIR analysis suggests that the binder is composed mostly of a protein resin and a small amount of lipid. The morphology of the pigment was investigated by SEM and EDS and the spectra revealed that the major elements present in the blue pigment are Na, Al, Si and S, with an overlap in the elemental mapping, indicative of ultramarine pigments. The GC-MS results are consistent with the type of binder identified by FTIR and indicate a mixture of oils, probably from vegetal sources, and proteins. [Display omitted] •Spectroscopic and chromatography methods were used in the characterization of blue paints in tombstones of cemeteries in São Martinho•SEM-EDX was used for the morphological study and determine the particle size of the samples.•The use of non-commercial paint was identified in the gravestones paintings.•This discovery is relevant for the preservation of funerary cultural heritage.