Publications by authors named "Mark G Mieritz"

Hormone contamination of aquatic systems has been shown to cause reproductive impairment of aquatic organisms. To assess to what extent beef and dairy farms represent a source of hormones to the aquatic environment, surface water runoff samples from three beef and dairy farms that utilize best manure management practices were evaluated for hormone concentrations (estrogens, androgens, progestogens) and estrogenic activity. Runoff was collected from weirs at the edge of each of six study fields from March 2008 to March 2010 and was analyzed for hormone concentrations using liquid chromatography with tandem mass spectrometry and for estrogenic activity using the E-screen bioassay.

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Hormone contamination of aquatic systems has been shown to have deleterious effects on aquatic biota. However, the assessment of hormone contamination of aquatic environments requires a quantitative evaluation of the potential effects of sample preservation on hormone concentrations. This study investigated the influence of acidification (pH 2) of surface water samples on the partitioning of hormones among filtrate, filter media, and filter-retained particulate matter.

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Degradation of hormones that may occur during storage of surface water samples can lead to underestimations in estrogenic and androgenic activities and inaccuracies in hormone concentrations. The current study investigated the use of sodium azide, hydrochloric acid (HCl), and sulfuric acid (H₂SO₄) to inhibit the degradation of hormones and estrogenic and androgenic activities in samples of surface water runoff from cattle manure-amended fields during storage at 4°C. Hormones and hormone metabolites were extracted using solid-phase extraction and analyzed using high-performance liquid chromatography (HPLC) with tandem MS.

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