EN
The occurrence of commonly used veterinary antimicrobial agents was investigated in 159 fresh water, 443 fish, and 150 sediment samples from Polish rivers and lakes. The agents included aminoglycosides, ß-lactams, diaminopyrimidines, fluoroquinolones, lincosamides, macrolides, pleuromutilins, sulfonamides, and tetracyclines. The analysis was performed by three different sample preparation procedures for each matrix and it was performed by liquid chromatography-tandem mass spectrometry with electrospray ionisation source in positive mode, under the same conditions. All analy tical methods used were validated and showed good sensitivity , accuracy, and precision. The LOQ was in the range from 5 µg/kg to 125 µg/kg for fish samples, from 0.02 µg/L to 10 µg/L for fresh water samples, and from 1 µg/kg to 8 µg/kg for sediment samples.