Physical Sciences and Mathematics Commons^™

The Reaction Of Caffeic Acid And Copper (Ii) In Natural Water, Ling Xiaozheng Xu

Masters Theses

The interaction of the lignin precursor compound caffeic acid with copper(lI) in aqueous solution was studied. In the presence of a reducible transition metal, such as copper, caffeic acid undergoes oxidation. Oxygen was shown to play an important role in the reaction. The UV-visible data demonstrated that the conjugated double bond in the propenoic acid side chain of caffeic acid slowly disappeared during the reaction. The molecular weight experiments indicated that the product was a dimer. FTIR spectrum agreed with two possible dimer structures involving the side chain of caffeic acid. In addition, the reaction was shown to be reversible. …

Photoionization With Excitation Of The 4s And 4p Subshells In Krypton, Ahmad Farhat

Masters Theses

High-resolution photoelectron spectra of the nd, Rydberg satellites in krypton have been measured for the first time for six different angles and for photon energies between 68.5 and 250 eV. The relative intensities of these satellites with respect to the 4s and 4p main lines are in very good accord with the most recent measurements of Krause et al. (1992) at 68.5 eV. They also confirm that the theoretical predictions for the relative intensity of these satellites are too high. We determine the ratios for nd satellites with respect to the 4s and 4p main lines, and extract the angular …

Application Of A Modified Analytical Derivatization Method To The Determination Of Microbial Metabolites In Aquifer Systems, Jie Lu

Masters Theses

The geochemical evolution of Low Molecular Weight Fatty Acids (LMWFA's) in various ground water samples and aquifer solid samples from both contaminated and uncontaminated sites has been studied. An improved analytical method has been established for both qualitative and quantitative determination of LMWFA's. The low molecular weight (LMW) organic acids are metabolic intermediates of the oxidative biodegradation of hydrocarbon contaminants. The hydrocarbons are believed to be the electron donors in these redox reactions. Formic and acetic acids were found to be the major LMWFA's in these ground water samples and aquifer solid samples. Their concentrations increase as the redox condition …

Identification Of Aromatic Acids As Microbial Metabolites Of Fossil-Fuel Compounds Present In Aquifer Systems, Daniel Michael Tomczak

Masters Theses

The identification and quantitation of aromatic acids as transformation products present in contaminated aquifer systems was studied from selected sites. These acids are formed as microbial metabolites in the oxidative degradation of aromatic compounds. The microbial activity in the subsurface can be coupled to the oxidation of the aromatic compounds and the reduction of specific inorganic indicators. Inorganic indicators identified from the sample sites include the reduced forms of iron, nitrate, sulfate, and dissolved oxygen.

The highest concentrations of the aromatic acids were found in the plumes of the contaminated sites. These concentrations also correlated with specific changes in concentrations …

Approaches To And Synthesis Of Chalcone Amides, Gregory S. Marczak

Masters Theses

A series of "chalcone" amides have been prepared. These amides are unique in the position of the substituted hydroxy and methoxy functional groups. Early approaches to the synthesis of the amides proved difficult when preparing intermediates from the phenolic substituents. These phenols were then protected to lead to easier formation of the intermediates, and then deprotected to yield the corresponding chalcone amides. The approaches to the preparation of these compounds is presented, along with the physical data used to characterize the chalcone amides.

Quantitative Analysis Of Steroids By 13C Nmr Spectroscopy, Pei Wang

Masters Theses

Steroids are usually analyzed quantitatively by using HPLC with ultraviolet detection and are confirmed by FTIR, GC-MS. Quantitative ¹³C NMR method provide an alternative means to analyze steroids. Chromatographic separation and subsequent identification by match with a spectroscopic data base spectrum is not required for quantitative analysis of mixture components. Instead, equivalent information is obtained by creating subspectra from resonances with equivalent peak areas within a quantitative NMR spectrum. Techniques for eliminating Nuclear Overhauser Enhancement (NOE) effect is described.