Rezidue antibiotika u neciljanoj hrani za životinje - razvoj osjetljive LC-MS/MS metodologije

Antimicrobial substances are used on farms for therapeutic, prophylactic, or growth-promoting purposes. Antibiotic residues can be detected in animal feed due to unauthorised use for prophylaxis and as growth promoters, or as a result of unintentional cross-contamination during feed production. The presence of antibiotic residues in food has been linked to allergic reactions, gut microbiota imbalance, development of antibacterial resistance, or potential toxic effects. A multi-residue method was developed for the detection and quantification of 43 analytes from 9 antibiotic classes (penicillins (2), quinolones (2), macrolides (3), lincosamides (1), phenicols (2), pleuromutilins (2), tetracyclines (4), sulfonamides (25), quinoxalines (2)) in animal feed. The method was designed for feed samples with varying contents and particle sizes. Extraction and purification were based on the addition of organic solvents and the solid-phase extraction (SPE) cleanup method to achieve the best analyte response. Antibiotics were detected by high-performance liquid chromatography-electrospray tandem mass spectrometry (UHPLC-MS/MS) within 17 minutes in positive and negative scan modes. Average recovery rates ranged from 75.7% (sulfamethazine) to 121.3% (carbadox) with corresponding relative standard deviations of 9.2% and 49.6%. The method is suitable for screening antibiotic contamination in animal feed in the range from 1 to 50 μg/kg and for confirming substances in the range from 10 to 1000 μg/kg. A significant matrix effect was observed when comparing the analysed signals between different feeds, indicating the necessity of using a matrix calibration curve and a standard addition method.