Retrospective screening of food contaminants in Total diet study (TDS) samples over more than a decade: Complementarity between LRMS and HRMS systems in food safety.

This study explores the potential of liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) for the retrospective analysis of samples from French Total Diet Studies. Composite babyfoods, sugary products and seafood samples were analysed by LC-HRMS using complementary targeted and suspect-screening approaches. Historical TDS analyses, carried-out using various compound-specific analytical methods, including LC/GC-MS/MS, had previously reported 28 chemicals in these samples. While direct comparisons with historical LC/GC-MSMS data are precluded by strong methodological discrepancies, LC-HRMS analysis provided additional chemical information on the archived samples. Indeed, 18 compounds were detected and confirmed (confidence-level 1), 21 could be annotated with a confidence-level 2a, while >100 features were detected but lacking MS/MS confirmation. LC-HRMS provided complementary data to historical monitoring and demonstrated its potential as an early-warning tool for reporting emerging chemicals. Operating in full-scan mode, HRMS systems generate comprehensive and complementary datasets that can be analysed retrospectively, supporting long-term food safety monitoring.