Micro-Raman spectroscopy for non-invasive study of Persian Binding mediums

Micro-Raman spectroscopy is recently advocated to be used for the identification of organic mediums of paintings although it is mainly used for identifying artists’ pigments. The current paper presents an effort for estimating the feasibility of micro-Raman spectroscopy for identifying Persian binding mediums used in historical paintings. To do so, samples were prepared in two main groups based on previous studies and the most popular Persian binding mediums; i.e., pure binding mediums and binding mediums mixed with red lead. Pure samples were themselves divided in three groups of carbohydrates, proteins and drying oils and were studied in 800-1800 cm-1 and 2500-3300 cm-1 regions. Results showed that micro-Raman spectroscopy can be more efficient in 2500-3500 cm-1 zone as most of pigments exhibit no Raman signal in this region. Moreover, the Raman spectrum of sarcocolla gum is provided in this article for the first time. This paper strongly suggests micro-Raman spectroscopy for identifying binding mediums used in Persian paintings.