Determination of estrogenic potential in waste water without sample extraction

This study describes the modification of the ER-Calux® assay for testing water samples without sample extraction (NE-(ER-Calux®) assay). The results are compared to those obtained with ER-Calux® assay and a theoretical estrogenic potential obtained by GC-MSD. For spiked tap and waste water samples there was no statistical difference between estrogenic potentials obtained by the three methods. Application of NE-(ER-Calux®) to “real” influent and effluents from municipal waste water treatment plants and receiving surface waters found that the NE-(ER-Calux®) assay gave higher values compared to ER-Calux® assay and GC-MSD. This is explained by the presence of water soluble endocrine agonists that are usually removed during extraction. Intraday dynamics of the estrogenic potential of a WWTP influent and effluent revealed an increase in the estrogenic potential of the influent from 12.9 ng(EEQ)/L in the morning to a peak value of 40.0 ng(EEQ)/L in the afternoon. The estrogenic potential of the effluent was