Simultaneous determination of 68 antimicrobial compounds in pigs oral fluid by ultra-high performance liquid chromatography-tandem mass spectrometry

Abstract

Improper use of antimicrobials in veterinary medicine can lead to residues in food of animal origin. Post-mortemmonitoring of antibiotics in animal products is carried out as part of official EU programmes on food safety andconsumer health. Oral fluid testing is a promising surveillance method to monitor appropriate treatment in pigsand to avoid residues in edible tissues. Oral fluid analysis can be implemented in an antibiotic residue controlprogramme, thus preventing economic losses due to meat disposal as a result of drug detection in tissues after thewithdrawal period.An analytical method was developed for the analysis of 68 compounds from 12 groups (penicillins, cephalosporins,sulfonamides, macrolides, fluoroquinolones, tetracyclines, aminoglycosides, pleuromutilins, diaminopyrimidines,lincosamides, polypeptides and sulfones) in pig oral fluid. Extraction of antibacterials wasperformed with 0.5 % formic acid. Analyses were carried out by ultra-high performance liquid chromatographywith triple quadrupole mass spectrometry (UHPLC-MS/MS) detection. The chromatographic separation wasachieved on a Zorbax analytical column (2.1 × 50 mm) with a mobile phase consisting of acetonitrile andheptafluorobutyric acid (HFBA). The total run time was 7 min. The method was validated as a confirmatorymethod according to the Commission Implementing Regulation (EU) 2021/808. The reliability of the methodwas verified by testing real samples from pig farms.