Comparison of two fluorescence immunoassay methods for the detection of endocrine disrupting chemicals in water

We describe two fluorescence immunoassays capable of detecting endocrine disrupting compounds in waste water. The first fluorescence method is a heterogeneous assay using total internal reflection fluorescence (TIRF) detection. The second method is a homogeneous assay that utilizes energy transfer (ETIA). Both fluorescence immunoassays are compared with respect to detection principle and ability to quantify the model analytes estrone, estradiol, and ethinylestradiol in a complex matrix regarding recovery rates and limits of detection. Calibrations were performed for the three analytes using both fluorescence methods. Limits of detection between 0.01 and 0.85 microg/l are achieved. In addition, measurements in synthetic waste water spiked with the analytes were performed. Both immunoassays allow the detection in waste water with recovery rates in the range of 70-112%.