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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Chromatographic analysis of aliphatic amines, organic N-chloramines and dicarboxylic acids in drinking water

Lavoie, Lisa Marie Clark 01 January 1999 (has links)
Concerns over the production of disinfection by-products formed when drinking water is chlorinated that may be toxic to humans, has increased the interest in alternative disinfection procedures such as ozonation and chloramination. The research in this dissertation concerns the development of analytical methodologies for organic chloramines, that are formed during chloramination and chlorination, and dicarboxylic acids that are formed during oxidation processes especially ozonation. Organic chloramines may have detrimental human health effects and interfere with the measurement of inorganic chloramine. Chromatographic methodologies for their determination are limited by the difficulty in extracting them from water, lack of standards and the lack of a chromophore for HPLC analysis. The research focused on three main areas: investigation of the feasibility of gas chromatographing the organic chloramines, investigating the compound independence of the newly developed nitrogen 388 line for the atomic emission detector, and the development of an extraction procedure for removing the organic chloramines from water. The final method employed solid phase microextraction (SPME). The SPME technique was optimized for both aliphatic amines and organic N-chloramines. Measurement of dicarboxylic acids, particularly oxalic acid, in drinking water was also investigated. They contribute to microbial growth in water and may react further to form halogenated disinfection by-products. Like the organic chloramines, their hydrophilicity and lack of a suitable chromophore hinder their analysis. Furthermore, direct gas chromatographic analysis of the dicarboxylic acids is not possible as they are not volatile. A gas chromatographic procedure for the analysis of short chain dicarboxylic acids was developed. An extraction procedure for oxalic acid using tributyl phosphate, an organic base is presented. The use of chloroformate reagents, particularly trichloroethylchloroformate, for the subsequent derivatization of mono and dicarboxylic acids is investigated. Although, the derivatization clearly formed the appropriate reaction product, cleanup of reaction by-products and reagents is problematic. Several strategies for removing these matrix affects are presented. A study for the characterization of human and veterinary sodium hyaluronate products was conducted. A procedure for the supercritical fluid extraction (SFE) and determination by HPLC for miconazole nitrate is presented.
2

Using passive sampling as a method for the analysis of hydrophobic pesticides and their analogs in sediment

Donahue, Cillian Elise January 2020 (has links)
No description available.

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