title: Detection and quantitative analysis of 21 veterinary drugs in river water using high-pressure liquid chromatography coupled to tandem mass spectrometry.
abstract: BACKGROUND
  The use of veterinary drugs in food production focuses on the control and improvement of animal health. The disadvantage of this practice is that pharmaceuticals and their metabolites are released into the environment, finding their way to natural water systems and becoming a potential risk to non-target organism.
  
  
  METHODS
  This paper reports the development and validation of a quantitative method, based on high-performance liquid chromatography coupled to tandem mass spectrometry, for the simultaneous analysis of 21 veterinary drugs, antimicrobials, corticosteroids, coccidiostats and antifungal agents, in surface water.
  
  
  RESULTS
  The precision of the method was established by calculating the mean recoveries, which were in the range of 94-101%. The developed method was employed to conduct the first monitoring study on the presence of veterinary drugs in the Galicia region, Northwest of Spain and was applied to 235 surface water samples. Eleven veterinary drugs were detected at concentrations from below the limit of quantification to 2,978.6 ng L(-1). Limits of detection and quantification were in the range of 6.2 (betamethasone, cortisone, decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 12.5 ng L(-1) (for the rest of the selected drugs) and 12.5 (betamethasone, cortisone, decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 25.0 ng L(-1) (for the remaining pharmaceuticals), respectively.
  
  
  CONCLUSIONS
  Sulfonamides were the group most frequently found, which are widely used in veterinary medicine.
authors.affiliation: Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Veterinary Medicine, University of Santiago de Compostela, 27002 Lugo, Spain.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Iglesias
authors.forename: Carolina
authors.initials: C
authors.lastname: Nebot
authors.forename: Jose M
authors.initials: JM
authors.lastname: Miranda
authors.forename: Beatriz I
authors.initials: BI
authors.lastname: Vázquez
authors.forename: Alberto
authors.initials: A
authors.lastname: Cepeda
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D045483:Rivers / Q000737:chemistry*; D013030:Spain; D013449:Sulfonamides / Q000032:analysis; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D019155:Veterinary Drugs / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D013449:Sulfonamides; D019155:Veterinary Drugs; D014874:Water Pollutants, Chemical