X-ray analytical techniques are increasingly being used to study manuscripts and works of art on paper, whether with laboratory equipment or synchrotron sources. However, it is difficult to anticipate the impact of X-ray photons on paper- and cellulose-based artifacts, particularly due to the large variety of their constituents and degradation levels, and the subsequent material multiscale heterogeneity. In this context, this work aims at developing an analytical approach to study the modifications in paper upon synchrotron radiation (SR) X-ray radiation using analytical techniques, which are fully complementary and highly sensitive, yet not frequently used together. At the molecular scale, cellulose chain scissions and hydroxyl free radicals were measured using chromatographic separation techniques (size-exclusion chromatography–multiangle laser light scattering–differential refractive index (SEC–MALS–DRI) and reversed-phase high-performance liquid chromatography–fluorescence detector–diode array detector (RP-HPLC–FLD–DAD)), while the optical properties of paper were characterized using spectroscopy (UV luminescence and diffuse reflectance). These techniques showed different sensitivities toward the detection of changes. The modifications in the cellulosic material were monitored in real time, within a few days, and up to 2 years following the irradiation to define a lowest observed adverse effect dose (LOAED). As paper is a hygroscopic material, the impact of the humidity in the environment was studied using this approach. Three levels of moisture content in the paper, achieved by conditioning the samples and irradiating them at different relative humidities (RHs), were studied (0, 50, 80% RH). It was shown that very low moisture content accelerated molecular and optical modifications.

中文翻译：

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X射线同步辐射对棉纸的短期和长期影响。

X射线分析技术正越来越多地用于研究手稿和纸上艺术品，无论是使用实验室设备还是同步加速器源。但是，很难预测X射线光子对基于纸张和纤维素的伪影的影响，特别是由于其成分和降解水平的多样性以及随后的材料多尺度异质性。在这种情况下，这项工作旨在开发一种分析方法，以利用分析技术研究同步加速器辐射（SR）X射线对纸张的修改，这些技术是完全互补且高度敏感的，但并不经常一起使用。在分子尺度上 使用色谱分离技术（尺寸排阻色谱法-多角度激光散射-微分折射率（SEC-MALS-DRI）和反相高效液相色谱法-荧光检测器-二极管阵列检测器）测量纤维素链断裂和羟基自由基（RP-HPLC–FLD–DAD）），而纸的光学特性则通过光谱学（紫外发光和漫反射率）进行表征。这些技术对变化的检测显示出不同的敏感性。辐照后几天内以及长达2年内实时监测纤维素材料中的修饰，以确定最低的观察到的不良反应剂量（LOAED）。由于纸是一种吸湿材料，因此使用这种方法研究了湿度对环境的影响。研究了通过调节样品并在不同的相对湿度（RHs）下辐照获得的纸张中的三个水分含量水平（0、50、80％RH）。结果表明，非常低的水分含量促进了分子和光学修饰。