Analytical challenges and recent advances in the determination of estrogens in water environments

Estrogens have been shown to be present in the water compartment, mainly due to the inefficient removal in wastewater treatment plants (WWTP). The concentrations of these compounds, although very low (low ng/L), are sufficient to induce estrogenic responses and alter the normal reproduction and development of wildlife organisms. The compounds have been determined, by a variety of analytical procedures, in the influents and effluents of WWTP, fresh waters, rivers, and even drinking waters. Determination of natural and synthetic estrogens and progestogens in natural water is, however, a difficult analytical task, because of the very low detection limits required and the complexity of the matrix. Thus, in general, complicated, time-consuming extraction and purification processes, usually based on the application of solid-liquid extraction, are performed before final determination by immunoassay, high-performance liquid chromatography, or gas chromatography, very often coupled with mass spectrometry. This paper reviews the analytical methods so far described for the analysis of estrogens, which are currently important environmental pollutants presented in natural and wastewaters. Discuss of the main steps, from sampling up to analysis, and the techniques most commonly used in the determination is presented.