Cu is an important trace element in living systems, including animals. It is a part of many enzymes responsible for different processes occurring in the body. However, antagonists can severely decrease the amount of Cu available to the animal, which results in numerous health issues caused by Cu deficiency. The main antagonists of the Cu are thiomolybdates whose effect is especially harsh in ruminants due to their high potential to synthesize these compounds. Thiomolybdates (the ions MoOxS4-x2- ,where x = 0-3) are formed in the rumen from molybdate and sulfide (from degradation of sulfate), both of which come from the food and water ingested by the animal.<p>
The first part of the project described in this thesis was to develop reproducible preparative methods of CuTM samples in solution and solids, under conditions as biologically relevant as possible. This crucial information is missing in the literature related to Cu deficiency. The second part studied the structure of the adduct formed between Cu and two of the thiomolybdates: tetrathiomolybdate, TM4 and trithiomolybdate, TM3, as these are the most important in Cu deficiency.<p>
In solution, the appropriate solution medium and the concentration of reactants were chosen to study the stoichiometry of Cu:TM in solution before precipitation occurs.<p>
Conditions for preparation of solid CuTM adducts were chosen to obtain the amount of solid necessary for further studies and to eliminate the formation of unwanted side-products. In the solid phase, the stoichiometry of Cu:TM was investigated by elemental analysis.
EPR spectroscopy of solid CuTM samples revealed the presence of diamagnetic species which were partially identified.<p>
EXAFS studies were performed on both the Mo and Cu K edges. Spectra defined the oxidation states of both main metal atoms, Cu and Mo. Fitting of the measured EXAFS spectra of solid CuTM samples prepared at three different Cu:TM ratios determined the interatomic distances involved in these compounds. This data was used to determine the structure of the CuTM units which polymerize to form the final product. IR spectroscopy was also used to confirm the presence of some of the groups in these adducts.<p>
All the results from the various spectroscopic techniques were then combined to proposed a complete reaction scheme for the two-step formation of the CuTM4 and CuTM3 adduct species.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-08062009-153213 |
| Date | 06 August 2009 |
| Creators | Kuzma, Darina |
| Contributors | Reid, Steve |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-08062009-153213/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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