title: Determination of clindamycin and its metabolite clindamycin sulfoxide in diverse sewage samples.
abstract: In a research project on risk management of harmful substances in water cycles, clindamycin and 12 further antibiotics were determined in different sewage samples. In contrast to other antibiotics, an increase of the clindamycin concentration in the final effluent in comparison to the influent of the sewage treatment plant (STP) was observed. A back transformation from the main metabolite clindamycin sulfoxide to clindamycin during the denitrification process has been discussed. Therefore, the concentration of this metabolite was measured additionally. Clindamycin sulfoxide was stable in the STP and the assumption of back transformation of the metabolite to clindamycin was confuted. To explain the increasing clindamycin concentration in the STP, the ratio of clindamycin sulfoxide to clindamycin was observed. The ratio increased in dry spells with concentrated samples and with long dwell time in the sewer system. A short hydraulic retention in waste water system and diluted samples in periods of extreme rainfall lead to a lower ratio of clindamycin sulfoxide to clindamycin concentration. A plausible explanation of this behavior could be that clindamycin was adsorbed strongly to a component of the sewage during this long residence time and in the STP, clindamycin was released. In the common sample preparation in the lab, clindamycin was not released. Measurements of clindamycin and clindamycin sulfoxide in the influent and effluent of STP is advised for sewage monitoring.
authors: Institute of Clinical Pharmacology, Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany, Reinhard.Oertel@TU-Dresden.de.
authors: Reinhard
authors: R
authors: Oertel
authors: Sara
authors: S
authors: Schubert
authors: Viktoria
authors: V
authors: Mühlbauer
authors: Bozena
authors: B
authors: Büttner
authors: Conrad
authors: C
authors: Marx
authors: Wilhelm
authors: W
authors: Kirch
mesh_terms: D002981:Clindamycin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification
chemical_list: D002981:Clindamycin; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical