Analysis Of Binding Media Of Polychrome Terracotta And Horses Of Qin Shihuang By Gas Chromatography-Mass Spectrometry

For analysis and identification of binding media used in the polychrome of Qin Shihuang Terracotta and Horses, gas chromatography-mass spectrometry combined with pretreatments such as solid phase extraction, ultrasonic assisted extraction, ion exchange resin purification and microwave-assisted hydrolysis was used for amino acids analysis, fatty acids analysis and saccharides analysis. By comparing the protein amounts, ester amounts and polysaccharide amounts in the samples, it was found that only the protein binding media was used in Terracotta and Horses of Qin Shihuang. The residue of protein was very low (only 0.89%o in weight. According to the features of hydroxyproline, glycine, glutamic acid and proline in binder and principle component analysis, it could be confirmed that the binder of seven samples were the mixture of animal glue and egg, two samples were the mixture of animal glue and casein, and one sample was the mixture of casein, egg and animal glue. From the analysis results, it was inferred that there might be not strict and consistent regulations about the usage of binding media in Terracotta and Horses in Qin dynasty. And for the Qin Shihuang Terracotta and Horses, the low amount of binding media residue was another important reason of color decoration falling off. So the Terracotta and Horses should be consolidated immediately after excavation.