The identification of binding agent used in late Shang Dynasty turquoise-inlayed bronze objects excavated in Anyang

The paper presents the results of the analysis of the binding media used in turquoise-inlay bronze artifacts in late Shang Dynasty, which were excavated in Anyang, Henan Province of China. Techniques applied include pyrolysis gas chromatography and mass spectrometry with thermal assisted hydrolysis and methylation (THM-Py-GC/MS), as well as GC/MS with derivatization reagent of MethPrep II. Marker compounds of urushi including methylated pentadecyl catechol and the oxidation products: 6-(2,3-dihydroxyphenyl) hexanoic acid; 7-(2,3-dihydroxyphenyl) heptanoic acid and 8-(2,3-dihydroxyphenyl) octanoic acid as their methylated forms were found, indicating Urushi (lacquer) was used as binding agents for the inlay. In addition, a series of fatty acids was detected with relative higher concentration of azelaic acid, which represents the presence of plant oil in the sample. Furthermore, a group of glue marker compounds and a series of long-chain fatty acids as well as a group of long-chain alcohols were detected in the sample.