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Degree

PhD, University of Cincinnati, Arts and Sciences : Chemistry, 2007.

Abstract

Due to varying properties of an element, depending on its chemical form, total element concentration is often not sufficient information for accurate assessment. Therefore, the analysis of the distribution of an element amongst various chemical species (termed speciation) is critical. By implemented combinations of various separation techniques (namely high performance liquid chromatography (HPLC) and gas chromatography (GC)) with mass spectrometric techniques such as inductively coupled plasma mass spectrometry (ICP-MS) and molecular mass spectrometry techniques, a powerful speciation tool is created. Elemental analysis using ICP-MS and speciation analysis can be used in complement to confirm species recovery and mass balance. When speciation information using HPLC/GC-ICP-MS does not provide enough information, molecular mass spectrometry techniques with softer ionization techniques (able to preserve structural characteristics) can enable confident identification of a given species. Arsenic, selenium, and phosphorus are extremely important elements and are much concern in several fields of research. In specific, arsenic and selenium are of interest due to the drastic difference in toxicity among their respective species. The main goal of this dissertation is to examine the distribution of arsenic, selenium, and phosphorus among various species for assessment of toxicity, nutritional value, and environmental impact. Wheat, potato, yam, and rice samples were examined to establish the impact of their consumption in regards to arsenic content. Selenium association with proteins was examined to further understand its biotransformation in mushrooms. The metabolism of selenium in genetically modified Brassica juncea was examined to further understand the selenium flow of the plant in hopes of creating a more efficient phytoremediation tool. Organophosphorus chemical warfare agent degradation products were chromatographically separated from inorganic phosphate (a common interference) in several food samples using a combination of HPLC-ICP-MS and HPLC-ESI-MS in an effect to detect food contamination.

Subject Headings

Chemistry, Analytical

Keywords

selenium; phosphorus; arsenic; speciation; ICP-MS

Advisor

Dr. Joseph A. Caruso

Pages

127p.

Document number: ucin1180714534
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1180714534

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