Dispersive liquid-liquid microextraction as a clean-up technique for identification of wine markers in figured pottery by HPLC-MS/MS

Chemical analysis of organic residues in archaeological pottery can provide useful information to validate the hypotheses made by archaeologists about key aspects of ancient daily life. Various non- invasive analytical techniques, such as Raman spectroscopy and Fourier-transform infrared (FTIR), can be used for investigations. However, chromatography coupled with different detectors is often preferred for separating and identifying the different components of complex matrices, such as archaeological pottery. This research aims to develop a new efficient, reproducible and rapid method for the identification of organic acids as wine markersin archaeological figured vessels through HPLC-MS/MS. Considering the artistic and historical importance of the vessels, in this work the sample amount was minimized: only 35 mg of archaeological sample were withdrawn. The procedure involves a derivatization step followed by an extraction developed in accordance with green analytical chemistry principles, involving ultrasound-assisted liquid extraction and dispersive liquid– liquid microextraction (dLLME) [1]. This technique enabled the removal of compounds that contribute to signal suppression, thereby reducing the matrix effect, achieving optimal extraction levels. The dLLME process required careful consideration of various parameters, including the type of dispersing phases, volumes, pH, and ionic strength. This method has been successfully applied to the analysis of figured pottery discovered in the Faliscan region.