The Occurrence of a Endocrine Disrupting Chemicals in the Shenandoah River in the Vicinity of an Agricultural Wastewater Treatment Plant Using Solid-Phase Extraction and Liquid Chromatography-Mass Spectrometry
Siddhant Bhatia, June Liu, and Thomas B. Huff
Background : Many waste water treatment facilities have been found wanting in the standard operating procedures. One such facility processes waste from two poultry processing plants and from two municipalities. Also, the facility discharges waste water into the river being sampled. Poultry waste can be applied to fields as a fertilizer and so as runoff occurs, the potential for high levels of estrogens to enter the river makes sampling opportune at times when the forecast is tempestuous. Evidence has been found that environmental endocrine disrupting chemical exposure can be associated with decreased male spermatogenesis and female oogenesis (Mills, 2004).
Objectives : The major objective is to determine the abundance of not only a particular chemical but also the abundance of all of the various forms of the chemical present in the sample. The specific endocrine disrupters examined in this study include estriol, genistein, coumestrol, bisphenol A, 17ß- estradiol, 17a- ethynylestradiol, estrone, diethylstilbestrol, 4- tert- octylphenol, and nonylphenol.
Methods: Solid Phase Extraction (SPE) was used to extract endocrine disrupting chemicals from river water and to concentrate the extracts for analysis. This process uses the affinity of a sorbent to remove the target chemicals which are then eluted with a strong solvent solution of 90% methyl tert -butyl ether (MTBE) and 10% methanol. Owing to the similarities between SPE and LC-MS their synergistic use makes for a potent analytical approach. The LC-MS was used to identify chemicals present at low concentrations in sampled water and to quantify those chemicals within the sample. This instrument is especially valuable because it combines the processes of liquid chromatographic separation with mass and charge relationship analysis for quantitative results. In order to determine the abundance of the endocrine disrupters mentioned above, the chromatographs generated by the instrument are analyzed.
Results: LC-MS analysis indicates high levels of atrazine, nonylphenol, coumestrol, genistein, estriol, estrone, and 4- tert -octylphenol in the Shenandoah River . Also, extremely high levels of nonylphenol were detected. Target chemicals that were not detected in the sample included diethylstilbestrol and 17a- estradiol.
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