Quantification of triiodinated benzene derivatives and X-ray contrast media in water samples by liquid chromatography-electrospray tandem mass spectrometry.

A method for the analysis of iodinated X-ray contrast media and possible metabolites in environmental water samples is presented. The method consists of a sequential solid-phase extraction followed by high-performance liquid chromatography coupled with tandem mass spectrometry for detection. The recoveries for the analytes in tap water varies between 70 and 100%. For matrix poor samples the detection limit is in the lower ng/l range. In case of native, complex samples the recoveries are lower and the parallel analysis of a spiked sample is necessary to obtain reliable data. With the presented method iodinated X-ray contrast media could be detected and quantified in a sewage treatment plant effluent, in a receiving channel and lake. In the receiving lake the concentrations are still high with values between 0.5 and 4 microg/l.