This article is part of the Journal of Raman Spectroscopy special issue entitled “Raman spectroscopy in art and archaeology” edited by Juan Manuel Madariaga and Danilo Bersani.
In situ Raman spectroscopy analysis combined with Raman and SEM-EDS imaging to assess the conservation state of 16th century wall paintings†
Version of Record online: 10 JUN 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Special Issue: Raman spectroscopy in art and archaeology
Volume 43, Issue 11, pages 1676–1684, November 2012
How to Cite
Irazola, M., Olivares, M., Castro, K., Maguregui, M., Martínez-Arkarazo, I. and Madariaga, J. M. (2012), In situ Raman spectroscopy analysis combined with Raman and SEM-EDS imaging to assess the conservation state of 16th century wall paintings. J. Raman Spectrosc., 43: 1676–1684. doi: 10.1002/jrs.4036
- Issue online: 21 NOV 2012
- Version of Record online: 10 JUN 2012
- Manuscript Accepted: 24 JAN 2012
- Manuscript Revised: 23 JAN 2012
- Manuscript Received: 7 DEC 2011
- Raman imaging;
- wall painting;
- conservation state;
- degradation products
A multianalytical methodology based on Raman spectroscopy was proposed to carry out the analysis of two wall paintings located in Saint Andrew Church (Biañez, Biscay) and Saint John the Baptist Church (Axpe, Biscay). On the one hand, Raman, assisted with energy-dispersive X-ray fluorescence and diffuse reflectance infrared portable spectrometers, was used in the in situ analysis of original support materials and pigments as well as in the identification of the degradation products. Such portable spectroscopic techniques allow identifying the areas to be sampled in order to perform deeper analyses by means of Raman chemical imaging and scanning electron microscope equipped with an energy dispersive spectrometer. Cross-sections were performed with the micro-samples taken in the areas of interest. Thereby, the colour palette, the mortar, the restoration processes and the degradation products were determined. The Raman analyses revealed that the transformation of gypsum into anhydrite in the intonaco layer was responsible for the detachment observed in the wall paintings from Axpe. Several hypotheses such as the harmful effect of previous restorations have been considered as precursor of the damage. Besides, decaying products, such as nitrates and oxalates, derived from physicochemical processes in the raw materials were also detected. Copyright © 2012 John Wiley & Sons, Ltd.