Implementation of spectroscopic techniques for characterization of icons of Deir El Sankoria, El Minia, Egypt

Abstract

Four icons from church of Saint Theodore El Shatby, Deir El Sankoria, El Minia, Egypt, have studied by micro-destructive spectroscopic methods: Attenuated Total Reflection–Fourier Transform Infrared Spectroscopy (ATR–FTIR), Raman Spectroscopy (RS), Field Emission Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy (FESEM–EDX), X-ray Photoelectron Spectroscopy (XPS) and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP–OES). This study gave information about the materials used in the icons painting, state of the icons, and evaluation of the effect of environmental conditions. ATR–FTIR and Raman methods showed the characteristic bands of lithopone and lead white as a ground material, gum Tragacanth as a binder, and chrome oxide green, mars yellow, mars red as a pigment. EDX microanalysis exhibited the elements of mars yellow and mars red pigments, and ICP–OES method showed the concentration of chromium element that is characteristic for chrome oxide green pigment. The results were authenticated by XPS method to ensure the materials used in the painting. SEM images showed the cracking of the paint surface. Degradation of the chemical structure of gum Tragacanth binder was attributed to metal oxides of the pigments in presence of sunlight and artificial light which led to promotion of the oxidation process and then deterioration of the painting through peeling of the painting surface and cracking of the paint film.