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.