Determination of antibiotics in different water compartments via liquid chromatography-electrospray tandem mass spectrometry.

For the determination of 18 antibiotics in water samples down to the lower ng/l range, an analytical multi method is presented. The analytes belong to different groups of antibiotics such as penicillins, tetracyclines, sulfonamides and macrolid antibiotics. Samples were enriched using a universal freeze-drying procedure or a solid-phase extraction facultatively. Analysis was performed by liquid chromatography with electrospray-tandem MS detection. Chromatography required different columns and eluents. Mean recovery rates were in excess of 70%, however, with one exception and a quantitation limit of 50 ng/l for the tetracyclines and 20 ng/l for all other antibiotics were set.