A NEW PYROLYSIS BASED METHOD TO ASSESS MOLECULAR PRESERVATION OF ANCIENT SILK PRODUCTS

Ancient silk products contain crucial information for understanding the culture and history of China where silk textiles were first produced and later monopolized. Silk products are also the critical material link between East Asia and Europe through both the ancient terrestrial and maritime “Silk Road”. Although pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis is a widely used molecular-level tool to analyze the decay stage and preservation conditions of ancient material, previous silk research that used Py-GC-MS only focused on specific aspects of silk, such as dyes, neglecting the actual silk. In addition to using various visual observations (such as light and electron microscopes) and chemical analyses (for example HPLC-High Performance Liquid Chromatography) on ancient silk textile unearthed from archeological sites, particularly those along the Silk Road, we report a new method that uses Py-GC-MS. Compound abundances from recovered ancient samples were compared with artificially decayed modern samples to discern burial and early diagenesis conditions. As compared with other studies on silk degradation (using methods such as high performance liquid chromatography), Py-GC-MS provides excellent peak separation and relatively quick results without time-consuming sample preparation nor large sample quantities. These Py-GC-MS molecular analyses on modern degraded silk and ancient silk samples can serve as a basis on which further morphological evaluation and isotope analysis can be performed.