A new concept for the bioeffects-related analysis of xenoestrogens: Hyphenation of receptor assays with LC-MS

The wide variety of known and unknown endocrine disrupters demands highly e fficient methods for detecting the relevant endocrine disrupting pollutants . Bioeffects-related analysis is expected to solve this problem, combining biomolecular recognition processes with chemical analysis, which therefore reduces costs of instrumental chemical analysis to relevant samples. The hy phenation of both steps provides information on potential bioeffects, struc ture and concentration of the substances of interest. In this work the hyph enation of an enzyme linked receptor assay (ELRA) with liquid chromatograph y-tandem mass spectrometry (LC-MSMS) for the analysis of estrogens and xeno estrogens is proposed. Both test systems have been validated with standards and spiked real water samples. The ELRA achieved a detection limit of 0.1 mu g/L for 17 beta-estradiol (without preconcentration). With the LC-MSMS m ethod, steroids could be detected down to 1 ng/L (with preconcentration). T wo concepts for a tighter hyphenation of biomolecular interaction and chemi cal analysis are discussed: the on-line coupling of receptor-affinity chrom atography (RAC) to LC-MSMS and the direct measurement of receptor-ligand co mplexes by LC-MSMS.