The scientific analysis of the bronze mous excavated from Wushan, Chongqing, China: new perspectives from alloy composition analysis and proteomic method

Abstract The bronze mou was an important artifact commonly used in the Ba-Shu region (now in Chongqing and Sichuan Province) during the Spring and Autumn Period and the Han Dynasty. Although extensive archaeological study of the bronze mou has been conducted, scientific analysis of the bronze mou has been limited, and no organic residue analysis has been performed on the bronze mou. In this study, four bronze mous dated to the Han dynasty (206 BC–220 AD) with organic residues unearthed in three archaeological sites in Wushan, Chongqing, were selected for analysis by portable X-ray fluorescent spectrometer (P-XRF) and liquid chromatograph-tandem mass spectrometry (LC/MS/MS). The results of the alloy composition indicated that all the samples are copper-tin-lead ternary alloys. The proteomic analysis results confirmed that the bronze mou had been used as cooking utensils or containers. At the Tuchengpo Cemetery, soybeans were found in both bronze mou M32:27 and M38:39, and vigna was discovered in M32:27. No useful protein was discovered in the bronze mou from the Shennvmiao Cemetery. Proteins of ginkgo and chicken were found in M16:12 at the Gaotangguan Cemetery. The discovery indicated that residents in Wushan, Chongqing, had access to a diverse range of food sources around 2000 years ago. Furthermore, this study demonstrates that proteomic analysis is highly effective in studying archaeological organic residues.