Engineering Commons^™

Determination Of Trace Quantities Of Selenium And Arsenic In Canned Tuna Fish Using Electroanalytical Techniques, Ann Marie Higham

Theses

Toxic metals are present in the environment and are known to be present in food. Selenium, which is considered an essential micronutrient, is recognized as a toxic metal at slightly higher concentrations. Arsenic is also recognized as a toxic metal. Selenium and Arsenic tend to accumulate in food, specifically fish and seafood.

Fifteen brands and types of tuna fish were analyzed for selenium using differential pulse cathodic stripping voltammetry. The cans with the high and low concentrations of selenium were analyzed for arsenic using differential pulse polarography. Three samples with three percent recoveries and a blank were analyzed for each …

A Study Of Parameters Indicating Microbial Activity In Mixed Aerobic Cultures, William Smith

Theses

Mixed liquor suspended solids (MLSS), oxygen uptake rate (OUR) and general dehydrogenase activity, as expressed by the reduction of the electron-acceptor Dye 3-(4',5'-dimethylthiazol-2-yl)-2, 4-diphenyltetra-zolium bromide (MTT), were compared for their ability to measure microbial activity in mixed aerobic cultures. A fourth parameter, specific enzyme activity, was dropped from consideration because of the difficulty of developing a satisfactory experimental technique. Measurement of the parameters was applied to the biodegradation of phenol and o-chlorophenol by activated sludge from a municipal sewage treatment plant, and by two commercially available bacterial preparations.

MLSS, although the most commonly used of the three parameters tested, is …

Protective Laboratory Measures For The Flexible Wall Permeameter And The Atterberg Limits Tests Using Hazardous And Toxic Chemicals, Robert A. Tetla

Theses

Safety procedures for performing geotechnical testing with hazardous and toxic materials, excluding radioactive wastes, are developed for the Flexible Wall Permeameter and the Atterberg Limits Tests. The tests were evaluated in detail to determine the critical points at which the technician would be exposed to the hazardous and/or toxic permeant. It was found that the following safety measures should always be taken; 1) the apparatus and all testing should be undertaken in a sliding sash hood using the proper face velocity, 2) air monitoring using a personal dosimeter and/or a detector tube is required to assure that the concentration of …

The Kinetics And Hepatotoxicity Of Benzyl Chloride Vapor In Rats, Hari V. Rao

Theses

Male Sprague Dawley rats (250g) were exposed to benzyl chloride vapor at a concentration of 220 ppm for 6 hours. During inhalation, the blood benzyl chloride concentration increased to reach a steady state level of 9-10 ug/ml between 4 and 6 hours of exposure. A small concentration of benzyl chloride (0.86 ug/ml) was present in the blood four hours after the termination of exposure. The absorption half life was 0.53 hours (0.39-0.81) and the elimination half life was l.12 hour (0.93-l.40).

The absorbed benzyl chloride was largely retained in the blood and some of it (0.22 ug/g) was sequestered into …

Scheduling Effects Of 5-(3,3-Dimethyl-1-Triazeno)Imidazole-4-Carboxamide (Dtic) And 1,3-Bis-Chloroethyl-1-Nitrosourea (Bcnu) On Mouse Melanoma Cells B16cl5, Gracie V. Coffey

Theses

DTIC and BCNU have been demonstrated to have enhanced chemotherapeutic effects in mice bearing Bl6 mouse melanoma cells. The order of administration seems to be important in maintaining optimum effects. This was shown is a study by Hill et al. (unpublished).

In the present study, mouse melanoma cells, Bl6CL4, were treated with either DTIC or BCNU. The drug was allowed to remain on the cells for 2, 3, or 4 days. The drug-containing media were then removed, the cells were washed and fresh medium was added. The cells were incubated in an atmosphere of 5% CO2 and 95% air at …