(cest2017_00889) Analysis of veterinary antibiotics in dairy environments by liquid chromatography - mass spectrometry

摘要

Veterinary antibiotics are widely used for diseasetreatment, protection and to promote animal's growth. Theemerging concern regarding the diffusion of antibioticresistant microorganisms (AMR) is directly linked to theuse of antibiotics in animal husbandry as they act as coselectivedrivers for AMR development and spread.Therefore, a new analytical method for the detection ofpharmaceuticals at trace levels to be able to study theiroccurrence, behaviour and fate in complex environmentalmatrices (including milk, wastewater slurry and soil) hasbeen developed. Several extraction techniques were testedin solid matrices for analytes under study such asultrasound assisted extraction (UAE) and microwaveassisted extraction (MAE), using different buffers andadditives. Clean-up and pre-concentration of the extractswere performed by means of solid-phase extraction (SPE),using different cartridges (e.g. SAX-HLB) and methanol aseluting solvent. Antibiotic residues were also extractedfrom milk samples using acetonitrile previous to SPEpurification or ultrafiltration. Recoveries were generallyabout 75% for most compounds, decreasing for thoseantibiotics having the highest instability (e.g. B-lactams).Identification and quantification of antibiotics wereperformed by liquid chromatography-mass spectrometry(LC-MS). Finally, the protocol proposed was validated byanalysing the concentration of target compounds insamples collected from a dairy farm.