scope:

This document specifies a method for the determination of the estrogenic potential of water and waste water by means of a reporter gene assay with genetically modified yeast strains Saccharomyces cerevisiae. This reporter gene assay is based on the activation of the human estrogen receptor alpha.

This method is applicable to:

- fresh water;

- waste water;

- aqueous extracts and leachates;

- eluates of sediments (fresh water);

- pore water;

- aqueous solutions of single substances or of chemical mixtures;

- drinking water.

The limit of quantification (LOQ) of this method for the direct analysis of water samples is between 8 ng/l and 15 ng/l 17β-estradiol equivalents (EEQ) based on the results of the international interlaboratory trial (see Annex F). The upper threshold of the dynamic range for this test is between 120 ng/l and 160 ng/l 17β-estradiol equivalents (EEQ). Samples showing estrogenic potencies above this threshold have to be diluted for a valid quantification. Extraction and pre-concentration of water samples can prove necessary, if their estrogenic potential is below the given LOQ.