Recent advances in LC-MS residue analysis of veterinary medicines in the terrestrial environment

Despite some European countries having banned the use of veterinary medicines for non-therapeutic purposes in food-animal agriculture, large amounts of pharmaceutical compounds, mostly antimicrobials, continue to be used for these purposes, as well as being used for the legitimate treatment of animal diseases.The high worldwide consumption of veterinary medicines has alerted scientists and the public in general, and efforts have been made to assess the concentrations levels of such residues (parent compounds, metabolites and degradation products) in the aquatic and terrestrial environments. As a consequence, reliable analytical methods have been developed for the identification and the determination of veterinary pharmaceutical residues in the environment.Probably because of the great complexity of solid environmental samples, only a few studies have been published on their determination in soils, sediments and sludge. Nevertheless, this information is needed to understand and to assess the impact of veterinary medicines on the environment.The important development of liquid chromatography coupled to mass spectrometry (LC-MS) in the environmental field has made this technique a powerful tool for reliable and accurate determination of pharmaceutical residues in the terrestrial environment.We aim to review the latest studies, pointing out the progress achieved in the LC-MS analysis (screening, identification, confirmation and quantification) of veterinary pharmaceutical residues in solid environmental matrices (soil, sediment and sludge), with especial emphasis on sample pretreatment and instrumental detection.