Development of a targeted LC-MS/MS method for the analysis of zero tolerance antimicrobials in buffalo meat

A simple, affordable, and efficient multiresidue analytical method was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to accurately identify and quantify a prioritized zero-tolerance antimicrobial residues in buffalo meat. Analyzing zero-tolerance antimicrobials such as chloramphenicol, metronidazole, and nitrofurans involves detecting even trace levels of residues in food products to safeguard consumer safety and public health. A modified QuEChERS method with 2-nitrobenzaldehyde derivatization using ethyl acetate was employed for the extraction of the antimicrobial compounds, followed by a suitable clean-up. Liquid chromatographic conditions were optimized on a reverse phase C18 analytical column over a runtime of 12 min, and the eluted analytes were observed in selected reaction monitoring mode (SRM). The method's performance was validated in accordance with Regulation (EU) 2019/1871 and Commission Implementing Regulation (EU) 2021/810 guidelines. The linearity of the calibration curves was > 0.99, and the mean recoveries of the analytes ranged from 81.92 % to 110 %. The intra-day and inter-day precisions were less than 9 %. The limits of detection (LOD) and limits of quantification (LOQ) were in the range of 0.04–0.11 µg/kg and 0.13–0.37 µg/kg, respectively. This is well below the MRLs set by the European Commission for zero-tolerance substances.