Improved analytical methods using novel cleanup techniques and inexpensive instrumentation for the determination of residue estrogens in municipal wastewater and swine lagoon wastewater have been developed. Presented approaches are less expensive, less time consuming, yet produce comparable detection limits and extraction efficiencies to existing methods. Chapter I provides an overview on environmental estrogens. Chapter II describes a novel method to quantify five estrogens including estriol, estrone, 17alpha-estradiol, 17beta-estradiol, and 17alpha-ethynylestradiol in influent and effluent municipal wastewater. The method includes sample preparation using solid-phase extraction followed by a “QuEChERS” cleanup, dansylation and LC/MS/MS detection. Hydrophilic-lipophilic balance solid phase extraction (SPE) was used for sample preconcentration and the extract was cleaned up using a dispersive SPE method using MgSO4, PSA and C-18. The resulting extract was then derivatized with dansyl chloride. Separation was achieved on a C-18 column and quantification was accomplished in the positive ion mode using multiple reaction monitoring. The method is capable of detecting below 1 ng/L. Chapter III describes improved approaches to quantify five estrogens and two conjugates, Estrone 3-glucuronide and beta-Estradiol 3-sulfate, in swine lagoon wastewater and storm water runoff. A considerable residue was collected when lagoon wastewater samples were centrifuged therefore both resulting residues and aqueous portions were analyzed separately. Analysis of the aqueous portions was carried out using a similar approach to the method described in Chapter II. However, a simple test-tube liquid-liquid extraction was used as an additional sample clean-up step. A modified QuEChERS method was utilized to efficiently extract the target analytes in the residue. Methods have 0.9 – 2 ng/L detection limits. Chapter IV describes an approach to quantify residue estrogens in municipal wastewater using a comprehensive two-dimensional gas chromatograph (GCxGC). This method requires no further cleanups after SPE and has detection limits ranging from 1.4 – 22.2 ng/L. All presented methods use relatively small initial sample volumes and produce negligible matrix interferences. The developed methods were validated by performing mini surveys on the estrogen levels in environmental aqueous matrices in north Mississippi.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-3642 |
| Date | 13 December 2014 |
| Creators | Gunatilake, Sameera Ranmal |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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