Journal of Food Safety and Quality

Objective To establish an analytical method for the determination of enrofloxacin residues in complex mixed matrix of the “soil-vegetable” system by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The sample was subjected to vortex ultrasonic extraction with acidified acetonitrile extract [containing 5% ethylene diamine tetraacetic acid (EDTA)-Mcllvaine buffer solution], settling with centrifugation, getting solvent conversion and being filtered by 0.22 μm nylon filter membrane. The mobile phase was composed of acetonitrile and 0.1% formic acid aqueous solution (containing 2 mmol/L ammonium acetate), and the mixture was subjected to Waters ACQUITY UPLC ? BEH C18 chromatographic column (2.1 mm×100 mm, 1.7 μm) gradient elution separation, using mass spectrometry as a detector for qualitative and quantitative analysis of enrofloxacin. Results In the mass concentration range of 1–200 ng/mL, the standard curve showed a good linear relationship (correlation coefficient=0.9996), the limit of detection of the method was 0.11 μg/kg, the recovery rates ranged from 87.4% to 103.3%, and the relative standard deviations (RSDs) were 0.4% to 4.0% (n=6). Conclusion This method has fast analysis speed, high accuracy and good repeatability, and is suitable for the detection of enrofloxacin residues in complex mixed matrix of the “soil-vegetable” system. It also has the potential to indirectly reveal the risk of antibiotic resistance genes (ARGs) contamination in the system.

enrofloxacin; ultra performance liquid chromatography-tandem mass spectrometry; “soil-vegetable” system; complex mixed matrix; antibiotic residues; antibiotic resistance genes