Emilien studied mass spectrometry under Professor Jean-Claude Tabet before beginning a PhD in mass spectrometry applied to food toxicology under the supervision of Laurent Debrauwer, which he defended in 2007. His work focused on the development of a quantification method using metastable atom bombardment ionization and on the characterization of covalent DNA adducts from heterocyclic aromatic amines. He joined the AXIOM team immediately after his PhD in 2007, where he develops and applies mass spectrometry methods in toxicology for the analysis and identification of xenobiotics, their biotransformation products, and metabolites in general, whether known or unknown. In 2016, Emilien took on the operational management of the team’s mass spectrometry activity, before becoming co-director of the team in 2023. On behalf of the team, Emilien is a member of the national metabolomics and fluxomics infrastructure MetaboHUB, and represents INRAE within the national exposomics infrastructure France Exposome.