Physical Sciences and Mathematics Commons^™

Export Of Terrestrial Dissolved Organic Matter Along A River To Ocean Transect Of The Lower Chesapeake Bay Investigated By Advanced Analytical Techniques, Rachel Leigh Sleighter

Chemistry & Biochemistry Theses & Dissertations

Ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) has proved essential for the complete separation of the thousands of peaks present in natural organic matter (NOM), a complex assemblage of organic molecules present in water, soils, and sediments. An improved understanding of its composition is crucial to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles.

Optimizing the acquisition and handling of the FTICR mass spectra is the first step to obtaining high quality data. A simple method to internally calibrate the peaks in the complex spectra, using naturally present fatty …

Relating Water And Otolith Chemistry In Chesapeake Bay, And Their Potential To Identify Essential Seagrass Habitats For Juveniles Of An Estuarine-Dependent Fish, Spotted Seatrout (Cynoscion Nebulosus), Emmanis Dorval

Biological Sciences Theses & Dissertations

A quantitative understanding of habitat use of estuarine-dependent fishes is critical to the conservation of their most essential habitats. Because recruitment and fitness may be influenced by the quality of juvenile habitats, developing methods to quantify habitat-specific survivorship is pivotal to such understanding. An initial step to quantify survivorship is to validate the habitat-specific natural tags contained in otoliths. To this aim I investigated the variability in the chemistry of surface waters and otoliths of juvenile spotted seatrout, Cynoscion nebulosus, in five seagrass habitats of Chesapeake Bay, namely: Potomac, Rappahannock, York, Island, and Eastern Shore. I measured Mg, Ca, …

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 …

Identification And Quantitation Of Volatile Amines In Chesapeake Bay Sediments, Neeraja Y. Krishna

Chemistry & Biochemistry Theses & Dissertations

Sediments from different parts of the Chesapeake Bay were analyzed to determine the presence of volatile amines. A HF-HCl extraction method was used to extract both exchangeable and fixed amines from the sediments and a purge-and-trap technique was used to concentrate the amines. Following derivatization with heptafluorobutyric anhydride (HFBA), the HFBA-amines were analyzed by gas chromatography with electron capture detection and with mass spectrometric detection. One primary amine, i-amylamine with a concentration ranging from 0. 78 nmoles/g dry weight to < 0.05 nmoles/g dry weight was found in a total of twenty seven samples collected on three different dates in 1993. Another primary amine, 2-methylbutylamine with a concentration ranging from 0.18 nmoles/g dry weight to < 0.05 nmoles/g dry weight was found in a total of twenty three samples collected on three different dates in 1993. A secondary amine, diethylamine was detected but could not be quantified in a total of seven samples collected in September 1993. The concentrations of these amines varied with location in the Bay, depth in the sediment, and time of year the sediments were collected. The origin of i-amylamine and 2-methylbutylamine might be from the biological decarboxylation of amino acids leucine and isoleucine, respectively. The origin of diethylamine is unknown.

Trace Metals And Pyrite In Sediments Of Chesapeake Bay, Robert S. Kluckhohn

OES Theses and Dissertations

The formation and cycling of iron sulfides within anoxic sediments can affect the cycling of trace metals. The sediments at station CB-27 (near Annapolis, Maryland) in Chesapeake Bay were rich in FeS (39% of TS), low in greigite (3.6% of TS), and has a relatively constant pyrite concentration (50 - 60% of TS) with depth. The percent composition of total metals in pyrite were 25.7% cu, 11.8% Zn, 15.8% Fe, and non-detectable to 2.1% Cd. At Station CB- 28 (near the Choptank River), the sediments were low in FeS (1.7% of TS), richer in greigite (up to 14% of TS), …

Alkalinity And Ph In The Southern Chesapeake Bay And The James River Estuary, George T. F. Wong

OES Faculty Publications

The ranges of alkalinity and pH in the southern Chesapeake Bay and the James River estuary were 2.25 meq·liter⁻¹ at 32‰ to

The Analysis Of Volatile Organic Compounds In The Southern Chesapeake Bay, Virginia By Gas Chromatography/Mass Spectrometry, James D. Haluska

OES Theses and Dissertations

Sea-water samples from the Norfolk, Virginia area were analyzed for trace volatile organic compounds by helium sparging. Contents of the trap were injected into a gas chromatograph/mass spectrometer. Analysis of the trap contents indicated the presence of aliphatic and olef1nic hydrocarbons containing up to six carbon atoms and eight halogenated compounds of up to two carbon atoms in length. The halogenated compounds which were identified were dichlorofluoromethane, trichlorotrifluoroethane, carbon tetrachloride, chloroform, trichloroethane (2 isomers) bromodichloromethane, and chlorotrifluoroethylene. The

relative concentrations of volatile organic compounds generally tended to increase in samples collected from water prone to urban environmental pressures. All eight …