Deterioration effects of X-ray irradiation in artificially aged parchment

The effects of X-ray irradiation, a potential disinfection method, produced in parchment samples with different extent of artificial ageing have been investigated to analyse the possible superposition effects of the irradiation-induced damage with the existing ageing associated deterioration. The study was carried out in modern parchment samples in which different degrees of artificial ageing were induced by exposing them to severe hygro-thermal conditions for various durations. The aged samples were subsequently irradiated with increasing X-ray doses (350-4000 Gy). The consequent deterioration effects were analysed using light transmission analysis (LTA), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and fibre optic reflectance spectroscopy (FORS) in order to evaluate possible changes in, respectively, the hydro-thermal stability, the collagen protein structure (hydrolysis/denaturation) and the optical absorption/reflectance properties of the collagen protein. The results show increasing additional deterioration with irradiation dose for non-aged and moderately aged parchment, until damage saturation occurs for more intensively aged samples where no substantial additional deterioration is induced by the irradiation. The combined results indicate that the ageing produces the more substantial deterioration with respect to that induced by the irradiation treatment employed for disinfection purpose.