Desalination Monitoring of Wooden Shipwreck Components of the Qing Dynasty Marine Shipwreck，Xiaobaijiao No.1
DU Jing1，JIN Tao2, HU Feng-dan1, ZHANG Chi1, ZHU Tie-quan3, ZHAN Chang-fa3, LI Nai-sheng1, JIA Zheng1, CHEN Yue1*
1. Chinese Academy of Cultural Heritage, Beijing 100029，China
2. Ningbo Municipal Institute of Cultural Heritage Management，Ningbo 315012，China
3. Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)，Zhuhai 519000, China
Abstract：The “Xiaobaijiao Ⅰ” shipwreck is a wooden commercial vessel designed for ocean-going, which sank in the Daoguang Reign of the Qing Dynasty (1821—1850 AD). Its hull structure of “the combination of Chinese and Western” has caught society’s attention. The desalination protection treatment mainly uses EDTA-2NA as completing agent. NaOH is prepared into a neutral solution, static water immersion and deionized water circulation are coordinated, and the desalting solution is changed periodically. In this paper, we used spectrophotometer, Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS), Elemental Analyzer-Isotope Ratio Mass Spectrometry, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Ion Chromatography (IC) to observe and test the characteristic hull components in desalting and the desalting solution samples of “Xiaobaijiao Ⅰ” for one year, in order to evaluate the desalting effects. The spectrophotometer results showed that the overall color distinct trend of the hull components of “Xiaobaijiao Ⅰ” is relatively stable, and the color difference changes are not obvious. Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS) test results show that the iron sulfide in the form of spherical particles is significantly reduced, and the iron sulfide is effectively removed. Elemental Analyzer-Isotope Ratio Mass Spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) test results show that the sulfur in the components is reduced to about 1 Wt%, and the iron in the desalting solution is overall low, the fluctuation range is not obvious, and it shows a slow downward trend. The removal rate of iron in the half section is decreased. Ion Chromatography (IC) showed that the content of SO2-4 in the desalting solution was very low and the change was small. K+, Mg2+, and Ca2+ are undetectable. The relatively high Cl- and Na+ content is explained by the two ions in the desalting reagent. Stopping the reagent and changing with deionized water can effectively reduce the content. Although the content of Cl- and Na+ fluctuates, the total amount of desalination has a minor change over one year, and a large amount of soluble salt has been eliminated.
Key words：Xiaobaijiao Ⅰ; Desalination; Iron sulfides; ICP-MS; IC
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