Institute of Materials Science, National Center for Scientific Research DEMOKRITOS, Neapoleos 27, Aghia Paraskevi, 153 10 Athens, Greece.
Anal Bioanal Chem. 2009 Dec;395(7):2227-34. doi: 10.1007/s00216-009-3135-8. Epub 2009 Sep 26.
Mortar that was used in building as well as in conservation and restoration works of wall paintings have been analysed isotopically (delta(13)C and delta(18)O) in order to evaluate the setting environments and secondary processes, to distinguish the structural components used and to determine the exact causes that incurred the degradation phenomena. The material undergoes weathering and decay on a large proportion of its surface and in depth, due to the infiltration of water through the structural blocks. Mineralogical analysis indicated signs of sulphation and dissolution/recrystallisation processes taking place on the material, whereas stable isotopes provided information relative to the origin of the CO(2) and water during calcite formation and degradation processes. Isotopic change of the initial delta(13)C and delta(18)O in carbonate matrix was caused by alteration of the primary source of CO(2) and H(2)O in mortar over time, particularly by recrystallisation of calcite with porewater, evaporated or re-condensed water, and CO(2) from various sources of atmospheric and biogenic origin. Human influence (surface treatment) and biological growth (e.g. fungus) are major exogenic processes which may alter delta(18)O and delta(13)C in lime mortar.
已经对用于建筑以及壁画的保护和修复工作的灰浆进行了同位素分析（δ¹³C 和 δ¹⁸O），以便评估其所处的环境和次生过程，区分使用的结构成分，并确定导致退化现象的确切原因。由于水通过结构体的渗透，材料的大部分表面和内部都会发生风化和腐烂。矿物学分析表明，材料上发生了硫酸盐化和溶解/再结晶过程，而稳定同位素则提供了与方解石形成和降解过程中 CO2 和水的来源有关的信息。碳酸盐基质中初始 δ¹³C 和 δ¹⁸O 的同位素变化是由于灰浆中 CO2 和 H2O 的主要来源随时间发生了变化，特别是方解石与孔隙水、蒸发或再凝结水以及来自大气和生物源的 CO2 发生了重结晶。人为影响（表面处理）和生物生长（例如真菌）是可能改变石灰砂浆中 δ¹⁸O 和 δ¹³C 的主要外源过程。
