| Estrogens are an environmental concern because low ng L-1 concentrations in water can adversely affect aquatic vertebrate species by disrupting the normal function of their endocrine systems. There is a critical need to accurately measure the concentrations of estrogens in dairy wastes---a potential source of estrogens to waterways. At present, however, there is a lack of suitable analytical techniques for measuring estrogens in dairy wastes and waste-impacted water resources. Therefore, the objective of this research was to develop methods to measure estrogens including estrone, 17alpha-estradiol, 17beta-estradiol, and estriol in flushed dairy manure wastewater (FDMW) and in surface and groundwater.; Enzyme immunoassay and gas chromatography-mass spectrometry (GC-MS) analytical methods for the measurement of estrogens were studied. Analysis of 17beta-estradiol by three immunoassays revealed that matrix effects significantly affected the accuracy of one or all of the immunoassays. An extensive sample preparation method involving chromatographic purification was deemed necessary so that estrogens could be measured by GC-MS. A new method was developed that enabled low ng L-1 measurements of estrogens in FDMW. Three estrogens were measured in FDMW: estrone, 17alpha-estradiol, and 17beta-estradiol. Estriol was not detected in FDMW.; To address concerns regarding possible contamination of surface and groundwater at a dairy, the new method was adapted for water samples and a survey experiment was conducted. During method development, it was found that interference affected the GC-MS quantification of estrogens in water samples. However, the sample preparation method appeared promising because, after accounting for interference, excellent extraction recoveries were observed. Measurable concentrations of 17alpha-estradiol, 17beta-estradiol, or estriol were not found in surface or groundwater at the dairy. Some estrone was detected in surface water that was directly impacted by cattle. However, a similar concentration of estrone was also measured in groundwater from a non-impacted location. Further refinement and validation of the method is needed for more conclusive studies of estrogens in manure-impacted water. |
