Development, validation and application of a wide-scope targeted and suspect screening of residues and contaminants in seafood and dairy products using QuEChERS-UHPLC-QTOF-MS

Abstract

Since food is a major route of exposure to chemical contaminants, this study aimed to develop and apply an innovative method to improve assessment of consumer exposure. Initially, a comprehensive targeted screening method was established for the simultaneous analysis of a wide range of residues (pesticides, veterinary drugs, and industrial chemicals) and contaminants (per- and polyfluoroalkyl substances (PFAS), mycotoxins, and alkaloids) in food matrices. The method was validated for 858 chemicals spiked at 0.001, 0.01, and 0.1 mg.kg^-1, following EU guidelines for pesticide residue analysis. Targeted screening of 872 (including 14 additional PFAS) chemicals revealed that 63% of the samples contained at least one contaminant, with 31 substances unequivocally identified. Finally, a supplementary suspect screening approach was used to compare MS/MS spectra, enabling the identification of 6 chemicals at level 1 and 109 chemicals at level 2a. These results demonstrate the robustness and value of a single first-line screening strategy across diverse complex food matrices, replacing at least five matrix-dependent targeted methods.

Keywords: LC-HRMS; Method validation; Multi-residue and contaminant method; QuEChERS; Screening method.