Portable Raman monitoring of modern cleaning and consolidation operations of artworks on mineral supports

• Published in: Analytical and bioanalytical chemistry Vol. 397; no. 7; pp. 2717 - 2725
• Main Authors: Martínez-Arkarazo, I, Sarmiento, A, Maguregui, M, Castro, K, Madariaga, J. M
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01-08-2010; Springer-Verlag; Springer
• Subjects: Analysis; Analytical Chemistry; Artworks; Biochemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Cleaning; Cleaning compounds; Consolidation; Food Science; Laboratory Medicine; Mathematical analysis; Mineral support; Minerals; Monitoring; Monitoring/Environmental Analysis; Original Paper; Portability; Raman spectroscopy; Restoration; Artworks; Portability; Restoration; Raman spectroscopy; Mineral support; Monitoring
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-010-3610-2

Any restoration performed on cultural heritage artworks must guarantee a low impact on the treated surfaces. Although completely risk-free methods do not exist, the use of tailor-made procedures and the continuous monitoring by portable instrumentation is surely one of the best approaches to conduct a modern restoration process. In this work, a portable Raman monitoring, combined sometimes with spectroscopic techniques providing the elemental composition, is the key analysis technique in the three-step restoration protocol proposed: (a) in situ analysis of the surface to be treated (original composition and degradation products/pollutants) and the cleaning agents used as extractants, (b) the thermodynamic study of the species involved in the treatment in order to design a suitable restoration method and (c) application and monitoring of the treatment. Two cleaning operations based on new technologies were studied and applied to two artworks on mineral supports: a wall painting affected by nitrate impact, and a black crusted stone (chalk) altarpiece. Raman bands of nitrate and gypsum, respectively, decreased after the step-by-step operations in each case, which helped restorers to decide when the treatment was concluded, thus avoiding any further damage to the treated surface of the artworks.