Orthogonal optimization of extraction and analysis for red wine residues in simulated and archaeological materials using LC/MS and HPLC methods

Identification of red wine residues in archaeological potteries can yield good insight into the development of red wine culture and the history of winemaking. In this work, the ultra- sonication extraction method was developed to extract the organic acids in simulated red wine residues, while the optimization of extraction condition was studied through orthogonal methods. Moreover, the availability of the proposed research method in archaeological research was also investigated by extracting and analyzing two real archaeological samples. The results obtained from the liquid chromatography/mass spectrometry (LC/MS) proved that the tartaric acid can be acted as the biomarker of red wine. The range analysis of orthogonal methods indicated that the temperature is the main factor on the extraction efficiency of tartaric acid, followed by the proportion of methanol in the solvent, and finally is the extraction time. More importantly, tartaric acid can be identified in the real archaeological sample using the proposed extraction and analysis method, indicating its high verifiability and reliability. This work would provide a complete set of analysis method to identify the traces of wine organic residues in archaeological samples, thus understanding the production and conservation of wine or even tracking back to the start brewing process of wine.