Characterization of natural degradation of historical Moroccan Jewish parchments by complementary spectroscopic techniques

In this work, we have explored the potentiality of energy dispersive X-ray fluorescence spectrometry (EDXRF), X-ray diffraction (XRD), the vibrational attenuated total reflection - Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM-EDS) for the characterization of the natural degradation of old parchment. The samples used in this work comprise four Moroccan Jewish historical parchments belonging to private libraries. The results have been correlated with those obtained by a selected modern parchment. The results obtained allowed for the first time an accurate insight into the chemical composition of these parchments. EDXRF Analysis of the samples allowed us to study some of the undertaken process along the preparation of parchments, such as the liming treatment using CaCO3. XRD was used to elucidate the collagen main features, to identify the inorganic composition of the parchments, and to evaluate the crystallinity changes upon natural weathering. FTIR spectroscopy enabled us to determine the changes of collagen material in response to natural ageing, overall oxidation (detection of bands at 1716 cm−1) and collagen gelatinization. SEM-EDS results disclosed the morphological surface changes occurring at different levels in the fibrous network of collagen, and have proved a poor conservation state in some parchments.