A Novel Analytical Strategy to Detect Specific Markers of Nitrofurazone from Protein-Bound Metabolites in Food Animals

Abstract

Abstract Accurate detection of nitrofuran residues, as an indicator of banned drug use, in animal-derived food products is vital for ensuring food safety. The accepted regulatory approach for nitrofurans produces a residue marker from their protein-bound metabolites, which is nonspecific for nitrofurazone (i.e., semicarbazide (SEM)). Since SEM may originate from non-nitrofurazone sources, it is therefore not conclusive for nitrofurazone. Our main objective was to apply novel deconjugation/substitution reactions, which have been used to reverse protein binding, to identify a specific nitrofurazone marker. Bound nitrofurazone metabolites, produced using S9 from bovine liver or homogenized bovine liver tissue, were subjected to basic media and thiol reagents. Analyses carried out using high-resolution mass spectrometry showed that substitution of protein with thiol reagents produced thiol-metabolite conjugates whose structures were supported with stable isotopically labeled experiments. These conjugates can serve as new, specific markers for conclusive detection of nitrofurazone abuse in food animals.

The authors' abstract, as published at the source. Journal of Agricultural and Food Chemistry, 2026 · DOI ↗