A Quantitative and Confirmatory Method Employing Liquid Chromatography Coupled to Hybrid High-Resolution Mass Spectrometry and QuEChERS for the Determination of Thirty-Seven Growth Promoter Residues in Bovine Urine

In this work, 37 growth promoters were quantitatively determined in bovine urine using a QuEChERS approach with acetonitrile, NaCl, and MgSO₄:PSA for sample extraction. The analytes were separated and detected by liquid chromatography coupled to hybrid high-resolution mass spectrometry. The method was validated in accordance with the Decision 657/2002/EC guidelines, in which recoveries fell within the range 84-113%, relative standard varied between 2 and 32%, and detection limit between 0.1 and 2.5 μg L^-1. An adequate performance was evidenced during a proficiency test evaluation, and the developed method has been applied to routine analysis of growth promoters in Brazil. A highlight is the easiness of sample extraction combined with a quantitative determination of forbidden drugs using high-resolution mass spectrometry, which enables retrospective analysis in a surveillance perspective.