Collagen chirality alteration, a result of amino acid epimerization from the L to the D form over time, has significant perspectives in bioarchaeology. This project explores the potential of chiral analyses by mass spectrometry to analyze collagen in archaeological remains, aiming to refine dating techniques and improve our understanding of preservation processes. The analytical strategy represents a major challenge. Indeed, the determination of the configuration of stereogenic centers constitutes the highest level of characterization for an organic molecule. In order to tackle such demanding structural identification level of the biomolecules of interest (collagen proteins), we aim at implementing fragmentation experiments in high resolution tandem mass spectrometry (HR-MS/MS) coupled to liquid chromatography (LC) and ion mobility (IM-MS) on non-covalent diastereoisomeric species generated in the gas phase between a metal and the chiral peptide issued from trypticn digestion of extracted collagen samples. Such LC-IM-HR-MS/MS method development will be carried out on modern samples to study abundant and non-precious collagen material. Our approach integrates collagen extraction, purification, and isotopic analyses (13C, 15N, 34S) to assess environmental and climate changes and agriculture and farming practices in Holocene Human Societies of the Western Mediterranean Basin. The method is validated using reference samples of known age, establishing a robust framework for applying amino acid epimerization as a chronological tool. By combining chiral analysis with 14C dating and multi-isotopic data, we propose a multi-parameter model that enhances the accuracy of organic material dating's and paleo-ecological and paleo-climate indicators; the method also creates a counterbalance to 14C dating and all the risks that this method brings.
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