Determination of sulfonamide antibiotics in forage grasses by an improved QuEChERS and multi-plug filtration cleanup method combined with UHPLC-MS/MS†

An improved QuEChERS method combined with Multi-Plug Filtration Cleanup (m-PFC) clean-up procedure was developed for the simultaneous determination of 16 different sulfonamides in forage grasses using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The forage grass sample was extracted with 0.1 mol L⁻¹ Na₂EDTA-Mcllvaine buffer and acetonitrile solution, purified by the Navo U-QuE column tube, separated by Agilent ZORBAX Eclipse Plus C₁₈ column, and analyzed by MRM (multiple reaction monitoring) mode and the internal standard method was utilized for quantification. The 16 different sulfonamides display good linearity within the range of 0.5–50 μg L⁻¹ (R² > 0.9967), the limit of detection was 0.02–0.5 μg kg⁻¹, and the limit of quantification was 0.05–1.0 μg kg⁻¹. Under the additive amounts of 1, 2, and 10 μg kg⁻¹, the recoveries were in the range of 72.3–116.9%, and the relative standard deviation was between 1.4% and 10.3%. The presented method showed the advantages of simple operation, excellent selectivity and high sensitivity. It was well-suited for both qualitative and quantitative analyses of sulfonamides in forage grass. Overall, this method provided a scientific basis for risk assessment, enforcement of quality and safety standards, and detection of sulfonamide residues in forage grass for import and export.