Multi-analytical techniques in characterization and identification of Chinese historical rubbings

For authenticity and conservation purposes, the precious historical rubbings preserved in Wuyuan Museum were studied by multi-analytical techniques including Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS), SEM-EDS and Herzberg staining method. Through Py-GC/MS analyses, five types of constituents could be detected: (1) polycyclic aromatic hydrocarbons from soot; (2) retene and methyl dehydroabietate from tar of conifer wood; (3) marker compounds of egg; (4) additives of menthol and curcumene compounds; (5) biochemical compounds of bark paper. Based on this analytical results, the ink type, binding media and additives in the ink, as well as the fiber origin source of the rubbing paper could be concluded. The materials information of the rubbings obtained through this study could not only provide evidence for its authenticity, but also supply scientific support for its conservation and restoration.