Accurate Identification of Common Soluble Salts in Cultural Relics
ZHAO Wen-hua1, 2, HAN Xiang-na1*, YE Lin2, BAI Jiu-jiang2
1. Institute of Cultural Heritage and History of Science & Technology, University of Science and Technology Beijing, Beijing 100083, China
2. Chongqing Culture Relics and Archaeology Research Institute (Chongqing Cultural Heritage Protection Center), Chongqing 400013, China
Abstract：Salt damage is a common and serious disease in porous cultural relics. Complex water and salt activities make the salt continuously destroy the cultural relics. Accurate identification of soluble salts in cultural relics is anessential prerequisite for studying the salt damage mechanism and management, and the design and development of appropriate protection materials for cultural relics. In this study, an operational procedure for the extraction and identification of soluble salts in cultural relics was established. Through the optimization of ion chromatography (IC), optical microscopy, infrared spectroscopy (FTIR), Raman spectroscopy (Raman), and scanning electron microscopy (SEM-EDS), accurate identification of common soluble salts in cultural relics has been achieved. The research shows that NaCl can be identified by IC (Na+ and Cl- in leachate), microscopic observation (cubic crystal) and SEM-EDS (mainly containing Na and Cl elements); CaCl2 can be identified by IC (Ca2+, Cl-) and SEM-EDS (Ca, Cl elements); Na2SO4 can be identified by IC (Na+, SO2-4), microscopic observation (clumped or cluster crystal), FTIR (main peaks 1 134, 637, 615 cm-1), Raman (main peak 993 cm-1) and SEM-EDS (Na, S, O elements); CaSO4 can be identified by IC (Ca2+, SO2-4), microscopic observation (hexagonal prism, needle or rod-shaped crystal), FTIR (1 144, 668, 603 cm-1), Raman (1 017 cm-1) and SEM-EDS (Ca, S, O elements); NaNO3 can be identified by IC (Na+, NO-3), FTIR (1 379, 1 353, 837 cm-1), Raman (1 071 cm-1) and SEM-EDS (Na, N, O elements); Ca(NO3)2·4H2O can be identified by IC (Ca2+, NO-3), FTIR (1 437, 1 367, 1 047 cm-1), Raman (1 059 cm-1) and SEM-EDS (Ca, N, O elements). In addition, cubic NaCl, clumped, cluster or flake Na2SO4, hexagonal prism, needle or rod-shaped CaSO4can be directly identified through microscopic morphology observation. CaCl2, NaNO3 and Ca(NO3)2·4H2O have strong hygroscopicity and have rapid deliquescence when exposed to room temperature, according to which it can be determined. This identification technology combines common instruments, has relatively low cost, is simple and easy to operate, and has reliable results. It can be used to accurately identify of soluble salts in cultural relics of different materials, with good prospects for application and promotion.
Key words：Culturalheritage conservation；Salt damage；Soluble salts；Analysis and identification
赵文华，韩向娜，叶 琳，白九江. 文物中常见可溶盐精确鉴别方法[J]. 光谱学与光谱分析, 2023, 43(12): 3826-3831.
ZHAO Wen-hua, HAN Xiang-na, YE Lin, BAI Jiu-jiang. Accurate Identification of Common Soluble Salts in Cultural Relics. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(12): 3826-3831.
