Occurrence of antibiotics in the aquatic environment

The recent monitoring of drug residues in the aquatic environment has gaine d much interest as many pharmaceutical compounds can frequently be found in sewage treatment plant (STP) effluents and river water at concentrations u p to several mu g/l. This article describes the analysis of various water s amples for 18 antibiotic substances, from the classes of macrolid antibioti cs, sulfonamides, penicillins and tetracyclines. Samples were preconcentrat ed via lyophilization and quantified using HPLC-electrospray-tandem-mass sp ectrometry. The investigated STP effluents and surface water samples showed frequent appearance of an erythromycin degradation product, roxithromycin and sulfamethoxazole with concentrations up to 6 mu g/l. Neither tetracycli nes nor penicillins could be detected at concentration levels above 50 and 20 ng/l, respectively. From the large number of ground water samples that w ere taken from agricultural areas in Germany, no contamination by antibioti cs was detected except for two sites. This indicates that intake from veter inary applications to the aquatic environment is of minor importance. (C) 1 999 Elsevier Science B.V. All rights reserved.