When LC-HRMS metabolomics gets ISO17025 accredited and ready for official controls - application to the screening of forbidden compounds in livestock.

Within the particular context of controlling chemical residues in food, an alternative to targeted approaches has emerged; it consists in the characterisation of physiological perturbations induced upon exposure of animals to a given chemical substance/class of substances to highlight suitable biomarkers addressing safety and/or regulatory issues. Metabolomics in particular has been investigated in the hope of identifying such biomarkers, and a range of studies have demonstrated the efficiency of the strategy. Until very recently, steps remained to be taken towards official or commercial implementation of corresponding tools. In particular, the lack of guidelines and criteria to validate such methods that do not target specific chemical species per se, constituted a bottleneck. In the present work, a metabolomics model dedicated to the detection of β-agonist administration in bovines has been developed and fully validated; criteria (selectivity, robustness, stability, suspicion threshold definition, false positive and false negative rates) have been proposed in agreement with EU expectations (Dec 2002/657), enabling demonstration that performances comply with screening requirements. Although some of the biomarkers involved in the prediction model remain un-elucidated, the corresponding LC-HRMS method has recently been ISO17025 accredited, allowing for the very first official implementation of a metabolomics based strategy within French National Monitoring Plans.