An integrated workflow for comprehensive lipid profiling in archaeological ceramic via isobutyl chloroformate derivatization and HPLC-ESI-Q-ToF-MS

In this study, we present a new integrated analytical workflow for the simultaneous extraction, derivatization, and profiling of acylglycerols (TAGs, DAGs, MAGs), fatty acids (FAs), and their oxidation products, such dicarboxylic acids and oxidized TAGs, in a single LC-MS run. Understanding the chemical composition of lipid residues is crucial, as ceramic vessels are among the most interesting archaeological remains for studying past human practices. The ceramic ability to preserve lipids over centuries, can offer valuable insights into ancient diets, trade, technologies, and rituals. However, the inherent chemical complexity of lipid residues and their strong interaction with ceramic matrices pose significant challenges in terms of extraction and analysis. To address these challenges, the proposed method combines optimized solvent extraction and alkaline treatment steps with a fast, cost-effective derivatization using isobutyl chloroformate, followed by HPLC-ESI-Q-ToF-MS analysis. This new approach was validated using spiked and artificially aged ceramics, showing good recoveries (60–102 %) and low limits of detection (∼0.02 μg/g). When applied to a middle republican impasto ware bottle from Baratti (Piombino, Italy), this integrated approach revealed a lipid profile compatible with olive oil, possibly mixed with another lipid material. This application demonstrates the reliability of the method, establishing it as a robust tool for future investigations of lipid residues in archaeological ceramics.