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Pcb Congener Analysis With Hall Electrolytic Conductivity Detection, Robert D. Edstrom
Pcb Congener Analysis With Hall Electrolytic Conductivity Detection, Robert D. Edstrom
Dissertations, Theses, and Masters Projects
This work reports the development of an analytical methodology for the analysis of PCB congeners based on integrating relative retention data provided by other researchers. The retention data were transposed into a multiple retention marker system which provided good precision in the calculation of relative retention indices for PCB congener analysis. Analytical run times for the developed methodology were approximately one hour using a commercially available GC capillary column. A Tracor Model 700A Hall Electrolytic Conductivity Detector (HECD) was employed in the GC detection of Aroclor standards and environmental samples. Responses by the HECD provided good sensitivity and were reasonably …
Uptake Kinetics And Toxicity Of Diazinon In The American Oyster, Crassostrea Virginica Gmelin, Ruth L. Williams
Uptake Kinetics And Toxicity Of Diazinon In The American Oyster, Crassostrea Virginica Gmelin, Ruth L. Williams
Dissertations, Theses, and Masters Projects
Several aspects of effects of the organophosphate pesticide diazinon on the American oyster Crassostrea virginica Gmelin were investigated. Uptake of diazinon directly from water was compared with uptake of diazinon sorbed to either fine sediment or algae; the primary route of assimilation seems to be from the water. Concentrations of diazinon between 0.91 and 2.03 mg/L inhibit shell growth during 96 hours of exposure; there is a sharp threshold of effect for this response which is probably an indirect one caused by lack of food during shell closure. Acetylcholinesterase inhibition is significant in oyster heart tissue at concentrations of approximately …
Effects Of Selected Nitrogen-Containing Aromatic Compounds (Ncacs) On Physiological Properties In Escherichia Coli, W. James Catallo Iii
Effects Of Selected Nitrogen-Containing Aromatic Compounds (Ncacs) On Physiological Properties In Escherichia Coli, W. James Catallo Iii
Dissertations, Theses, and Masters Projects
This research examined the effects of quinoline and 4-azafluorene on respiratory electron transport rate (ET), outer membrane permeability and topology, oxygen consumption, and viable cell density in Escherichia coli cell suspensions. ET was estimated spectrophotometrically using INT (2-(p-iodophenyl)-3-(p-nitrophenyl)-5-(phenyl)-2H-tetrazolium chloride, which is reduced in vivo to a red colored formazan (INTF). Both test compounds caused anomalous dose-response behavior in INT assays: in a defined window of doses, ET rates near or above the controls were observed. These doses showed altered INT reduction kinetics, decreased cellular oxygen demand, and decreased viable cell densities. Experiments with E. coli spheroplast preparations, gram(+) cells, and …
The Standing Stock Of Organic Matter In A Man-Made Brackish Marsh And Its Resource Management Implications, Pamela Anne Mason
The Standing Stock Of Organic Matter In A Man-Made Brackish Marsh And Its Resource Management Implications, Pamela Anne Mason
Dissertations, Theses, and Masters Projects
No abstract provided.