Digital Commons Network^™

Humic Substances As Interferences In The Analysis Of Nitrite In Water, Stephanie Ann Tebault

Chemistry & Biochemistry Theses & Dissertations

Humic substances are of current interest because of their roles in environmental processes involving pollutants. It is also becoming recognized that humic substances may interfere in analysis of environmental samples though the possible adverse effects do not appear to be fully appreciated. The present effort focuses on determining whether humic materials interfere in the analysis of nitrite in water using the Griess reaction. This is a well-known reaction using nitrosation to gjve a diazonium salt followed by coupling with an appropriate reagent to form a dye. This colorimetric method continues to be applied in the laboratory and the field for …

Zinc Speculation And Ligand Fluxes In Chesapeake Bay And Elizabeth River Pore Waters, Duncan Glover Byers

Chemistry & Biochemistry Theses & Dissertations

Presented here are the first data on the vertical concentrations, complexation, speciation, and fluxes of total dissolved zinc and zinc complexing ligands, and zinc speciation in sediment pore waters in the Chesapeake Bay and Elizabeth River, Virginia.

Sediment pore waters were collected in mid and southern Chesapeake Bay in November 1997 and in the Elizabeth River (Pinner's Point) in March, April, and July 1998. Flux experiments were conducted in Elizabeth River sediment cores in April and July 1998. [TDZn] and zinc complexation were determined using differential pulse anodic stripping voltammetry at a hanging mercury drop electrode (DPASV-HMDE).

[TDZn] in the …

The Binding Of Selected Xenoestrogens To An Estrogen-Binding Fraction, Willie L. Washington

Electronic Dissertations and Theses

The purpose of this study was to test the hypothesis that effects of xenoestrogens may be mediated through a low-affinity estrogen-binding site. This low-affinity estrogen-binding site (EBS) is found in rat uterus. A second receptor, the Type I-(high-affinity-EBS). is also present in the uterus and other tissues. In order to obtain the estrogen-binding fraction-from the uterus, an ammonium sulfate (AS) fractionation was performed on rat-uterine cytosol. Two fractions were made, a 40% AS, which contained the Type I estrogen receptor (ER) and a 70¾ AS fraction that contained the low-affinity estrogen-binding site. These fractions were assayed for their ability to …

Identification And Characterization Of Biological And Volatile Organic Contaminants In Indoor Air In A Governmental State Office Building, Denesia A. Wallace

Electronic Dissertations and Theses

The purpose of this study was to identify and determine the concentrations of targeted inorganic gases and total volatile organic compounds known to exist in indoor air spaces. The Louisiana Department of Environmental Quality (LADEQ) Office Building was selected because of a survey of occupants' symptoms and perceptions of indoor air quality. Collected air samples were analyzed for selected compounds by way of United States Environmental Protection Agency (USEPA) sampling procedures and methods that utilized drager absorption tubes and a gas chromatograph/mass spectrometer. The targeted compounds were nitrogen dioxide, dinitrogen oxide, carbon monoxide, VOCs (volatile organic compounds), formaldehyde, and carbon …

Monitoring The Effects Of Indoor Pollution Using Fourier Transform Infrared Spectroscopy, Rachel Farrell

Presidential Scholars Theses (1990 – 2006)

Fourier Transform Infrared Spectroscopy {FTIR) was used to develop an effective way to monitor indoor pollution and to observe the effects of such indoor pollution under various conditions of the ventilation system of McCollum Science Hall of the University of Northern Iowa, Cedar Falls, Iowa. This was done by monitoring the absorbance of acetone as it evaporated over time, and the data were used to create concentration vs. time plots. Several parameters from these plots were used to judge the ventilation system, with some general conclusions including that having the system on reduces peak time and end time. Also, the …