Determination of Optimal Conditions for Sample Storage and Preparation: Enhancing Estrogen Extraction From Soils.

Recent studies have shown that there is a need for sensitive and rapid detection methods for estrogens as these contaminants are present at extremely low concentrations in the environment. At the sample preparation stage, extracting estrogens from soil samples is difficult because estrogens are moderately hydrophobic and can be strongly sorbed to soils especially those with high organic carbon contents. Techniques for sample storage and preparation need to be better developed to enhance extraction efficiency. The main objective of this study was to determine the optimal conditions for sample storage and preparation (extraction and cleanup) of soils containing estrogens (particularly estrone, 17α-ethynylestradiol, and 17β-estradiol). In this study, soil samples of the Hublersburg series were collected from a wastewater irrigated site (The Living Filter), in central Pennsylvania. The Pennsylvania State University uses this wastewater irrigation system to promote water reuse and has been in full scale operation since the 1980s. The soils are silt loam in texture and are very deep and well drained. These soils have been receiving wastewater irrigation (two inches of wastewater per week throughout the year) for over 20 years. The collected soil samples were sub-sampled to determined background estrogen levels as well as pH, EC, and organic carbon content. The remaining soils were then spiked with the estrogen of interest to evaluate method efficiency and repeatability. Method recovery rates using the HPLC-MS-MS were used as an index for determining the optimal conditions for sample storage and preparation and will be presented here.