Analytical Chemistry Commons^™

Spectral Characterization Of Cytochromes P450 Active Sites Using Nmr And Resonance Raman Spectroscopy, Remigio Usai

Dissertations (1934 -)

The Cytochrome P450 (P450s) has been the subject of intense research for over six decades. An efficient approach for isotopic labeling of the prosthetic group in heme proteins was exploited to produce an analogue of the soluble bacterial cytochrome P450cam (P450cam) that contains a 13C labeled-protoheme prosthetic group. HU227 strain of E. coli, which lacks the δ-aminolevulinic acid (δ-ALA) synthase gene, was employed in the heterologous expression of P450cam harboring a prosthetic group labeled with 13C at the Cm and Cα positions by growing cells in the presence of [5-13C] δ-ALA, which was synthesized in four steps from [2-13C] glycine. …

Redox And Spectroscopic Properties Of Protonated Species Of Iron Porphyrin Nitroxlys And Their Analogues, Md. Hafizur Rahman

Dissertations (1934 -)

Nitrite reduction to ammonia or nitrous oxide involves a series of electron transfer and protonation steps which are carried out by assimilatory or dissimilatory nitrite reductases. In the assimilatory process, nitrite incorporated into the biomass while in the dissimilatory process, it is excreted from the cell and the reaction is a source of energy. The complexes that will be studied in this work are models for assimilatory (siroheme) and dissimilatory (heme d1 ) nitrite reductases. Iron porphyrin nitrosyls were reduced in the presence of weak acids such as phenol and substituted phenols. Voltammetric techniques such as cyclic and rotating ring …

Synthesis And Characterization Of Low Valent Metalloporphyrins, Nagabhushanam Kundakarla

Master's Theses (2009 -)

Metalloporphyrins and metalloporphinones have been seen in a number of enzymes and involved in nitrogen metabolism, photosynthesis, and methanogenesis. The reduction of metalloporphyrins and metalloporphinones are achievable, but the site of reduction in either, the metal center or porphyrin core is still debatable. This prompted us to investigate the position of reduction in order to generate low valent metalloporphyrins and porphinones. The reduced porphyrins were characterized by spectroscopic and X-ray crystallographic methods. Previous work in our laboratory has generated low valent metalloporphyrins and porphinones by electrochemical reduction. In this work cobalt, manganese, and iron low valent metalloporphyrins were generated via …

Resonant Two-Photon Ionization Studies Of Non Covalent Interactions In Halo Aromatic Clusters And Spin-Orbit Coupling Modeling In Mono-Halocarbenes, Silver Nyambo

Dissertations (1934 -)

Non-covalent interactions in halobenzenes (PhX) (X=F, Cl, Br) and phenylamine (C₆ H₅ NH₂ ) have been studied here using resonance two-photon ionization (R2PI) spectroscopy combined with a linear TOF-mass spectrometer. Their interaction with polar molecules in form of ammonia (NH ₃ ) and trifluorohalomethanes (CF₃ X) has also been studied. DFT and TD-DFT calculations using M06-2X functionals were carried out on different cluster conformations to compliment experimental results. A general trend of broadness in homogenous dimers (PhX)₂ , has been attributed to mainly the presence of multiple cluster isomers and Frank-Condon activity in the low …

Development And Applications Of Ionic Liquids And Near-Infrared Multispectral Imaging Techniques, Irena Mejac

Dissertations (1934 -)

In this work, we explore novel analytical applications of Ionic Liquids and Near-infrared multispectral imaging microscopy.

Ionic liquids (ILs) belong to a group of organic salts that are liquid at room temperature and can be, due to their unique chemical and physical properties, successfully used for a variety of applications. The main goal of this study was to explore the synergistic use of ILs in chemical separations. Specifically, chiral ILs were used as novel chiral selectors for Capillary Electrophoresis and as solvents for stationary phase in Gas Chromatography. As chiral selectors IL provides baseline-separation as well as enantiomeric separation of …

Spectroelectrochemical Studies Of Metalloporphyrins In Room Temperature Ionic Liquid, Yong Soo Hoo

Master's Theses (2009 -)

The oxidation/reduction reactions of porphyrins and metalloporphyrins play an important role in medicinal, industrial and biochemical reactions. Metalloporphyrins are particularly useful as potential catalysts for a variety of processes including catalytic oxidations. The unique properties of metalloporphyrins make them good candidates as electrocatalysts for fuel cells. Metalloporphyrins also play some important roles in biological functions.

By incorporating spectroscopic experiments such as UV-visible or infra-red spectroscopy along with electrochemical experiments such as cyclic voltammetry, one is able to determine the structural changes of the molecule when oxidation or reduction reaction is carried out.

Analysis Of Liquid-Phase Chemical Detection Using Guided Shear Horizontal-Surface Acoustic Wave Sensors, Zhonghui Li, Yolanda Jones, Jeanne M. Hossenlopp, Richard Cernosek, Fabien Josse

Chemistry Faculty Research and Publications

Direct chemical sensing in liquid environments using polymer-guided shear horizontal surface acoustic wave sensor platforms on 36° rotated Y-cut LiTaO3 is investigated. Design considerations for optimizing these devices for liquid-phase detection are systematically explored. Two different sensor geometries are experimentally and theoretically analyzed. Dual delay line devices are used with a reference line coated with poly (methyl methacrylate) (PMMA) and a sensing line coated with a chemically sensitive polymer, which acts as both a guiding layer and a sensing layer or with a PMMA waveguide and a chemically sensitive polymer. Results show the three-layer model provides higher sensitivity than the …

A Study Of Temperature Dependent Electrical Properties Of Ion-Implanted Gallium Arsenide, Shanmugam Sundaram

Master's Essays (1922 - )

Two samples, GaAs:Mg (p-type) and GaAs:Si (n-type), ion-implanted to the same does of 5x10¹² ions/cm². were investigated to study their temperature dependent electrical properties. The resistivities and Hall constant were determined directly by Van der Pauw Technique. Sheet carrier concentration and carries mobility were then calculated. The Silicon sample, in which the properties were relatively temperature independent, was found to be in the metallic conduction range. Hence the magnesium sample was chosen for further temperature dependency investigation.

Benzoylation Studies With A Compound Reported To Be Benzoyl Acid Sulfate And Analytical Studies On The Sample, Robert J. Peanasky

Bachelors’ Theses

A very valuable reagent in organic characterization work is benzoyl chloride. By interacting benzoyl chloride with any one of the general classes of compounds termed phenols, alcohols, and amines, solid and very satisfactory derivatives are usually produced. However, the action of this compound occurs rather slowly and the operator, unless especially careful, suffers from the lachrimatory effects of the reagent, benzoyl chloride. A sample was submitted to my major professor, Dr. C. R. Haymaker, by Gene LaFave who claimed that it was benzoyl acid sulfate. This compound was a solid not difficult to manipulate in contradistinction to the lachrimatory liquid …

Statistical Evaluations Of Copper Determination, Waldemar A. Rosenthal

Bachelors’ Theses

In the field of applied Analytical Chemistry, where the amount of material is continually being determined, it is valuable to know whether or not the particular method in use is both accurate and precise. Basic course work in college provided the author an appreciation of numerical facts, but there always remained unanswered questions as to how these numerical facts could be employed to best represent the correct results. The difficulties were resolved by this thesis which will show how the evaluation of numerical data was considered with reference to the method used in determining the amount of copper present in …

Statistical Evaluation Of Laboratory Data Obtained From Two Methods Of Volumetric Analysis Of Titanium Compounds, Louis S. Winter

Bachelors’ Theses

Titanium at last has entered the sphere of scientific practicality and general usefulness. It has overcome its position as an orphan of chemical interest and has been showered with the foistings of many industries. With this in mind, it is soon evident that a rapid and feasible system of analysis must be set up. Titanium presents a number of problems in the field of analytics, which are seldom, if ever, encountered when dealing with the commoner elements as iron, copper and tin. The purpose here is to study two methods of determination from the many which chemists have suggested and …

The Preparation Of Ammonium Tetrachloro Diiodo Stannate, Stanley M. Polewski

Bachelors’ Theses

The commercial application of mixed halogen compounds in comparison to that of mono-halogen compounds is very limited. It is probably for this reason that the amount of work done in the attempt to prepare mixed halogen compounds has been very small. The author has tried, in a small way, to help fill this large gap by attempting to prepare the compound, ammonium tetrachloro diiodo stannate.

The Determination Of Interfacial Tension Using Pendant Drop Method, Katherine Tellor

Bachelors’ Theses

Boundary tension is a measure of the free energy of a fluid interface. It is a term derived from the superficial analogy between the surface of a liquid and a stretched membrane. Just as the potential energy of a fluid mass in foot pound per pound is spoken of as a "head" in feet, so it is useful to speak of free energy of a fluid surface in ergs per square centimeter as a "tension" in dynes per centimeter.

The Effect Of Time, Temperature, And Pressure On The Hydrogenation Of A Mixture Of Linoleic And Oleic Acids, Gordon S. Wepfer

Bachelors’ Theses

During the past few years interest and experimentation in the field of hydrogenation of different fats and oils has increased enormously. Strides made in the oil-hardening industry have surpassed all expectations. These advances were brought about by simplifying old methods and creating new ones. The probable reasons for this impetus in research is due to the fact that unexpected uses for hydrogenated oils and fats have been found and will continue to be found. With the increase in use of these products the market for them will also increase. Recently, the resin industries have produced useful products by condensing pure …

A Study Of Resins From Carbohydrates, Edward F. Sullivan

Bachelors’ Theses

The availability of large amounts of carbohydrates, and the need in the past years of larger markets for the available supplies of sugar have lead a number of sugar companies to investigate the possibilities of synthetic resins from carbohydrates. Although in the last ten or twelve years, a number of steps have been taken in the investigation of sugar resins, the information available has been restricted to a few patents. Consequently, information on the chemistry of the problem has been neglected. Thus, this work, for the most part, covers partially the possibilities of producing alkyd resins from saccharides, as well …

A Method For Comparing And Measuring The Drying Time Of Glues, William C. Strutz

Bachelors’ Theses

The measurements or quality in glue testing are arbitrary and are of value only when compared to a standard glue or when comparing one glue to another. Glues have been used for hundreds of years, but it has been only in the last forty or fifty years that any scientific investigations of any consequence have been made. Prior to this time glues were made by rule of thumb by practical men who learned the art of glue making from other practical men in the business and by contact with the industry. "When the United States entered the Great War and …

The Preparation Of Calcium And Barium Gluconate, Ronald Anthony Plzak

Bachelors’ Theses

The privilege of working on this subject is one which the author has sincerely appreciated, as it has given him the opportunity of incorporating many of the more recent contributions along the line of oxidizing aldose sugars. In reviewing these contributions, he has abstained from conveying an impression of finality and has attempted to show the many possibilities which the free sugar acids offer for the future. The experience of the last few years has proved that even long-cherished conceptions and apparently well-established facts may at any time undergo drastic revision. For this reason, the author has referred directly to …

A Comparison Of The Caffeine Content Of Various Coffees, Emil J. Petrusek

Bachelors’ Theses

Coffee must be rated as one of the most important commodities in the commercial world due to the statistics or output and consumption. There are various brands and kinds of coffee produced by the different growers and roasters. Now to sell the brands, the various concerns base their advertising upon the flavor and price of the coffee. It is a fact that the flavor of coffee is in some way affected by the caffeine present. One popular brand is advertised as decaffeinated, that is, the caffeine has been removed. Confronted with these facts, it occurred to the author to test …

The Extraction Of Tantalum And Columbium From Tantalite, Stanley P. Wisniewski

Bachelors’ Theses

In the summer of 1932, the Milwaukee Public Museum, sent an expedition to the Bad Lands and Black Hills of South Dakota, under the direction of Dr. Ira Edwards, Curator of Geology in that institution. It was at this time that the author, a member of this group, while studying the pegmatites of the Black Hills, became interested in the tantalum-columbium bearing minerals of that region, namely tantalite and columbite. At that time the writer made a detailed mineralogical study of these two minerals, as well as a thorough investigation of their occurrence in that region. In the fall of …

Wax Analysis With Special Reference To Montan, Spermaceti, And Chinese Insect Wax, Margaret M. Plonsker, Margaret E. Seippel

Bachelors’ Theses

The presentation of this thesis under joint authorship finds its justification in the fact that much of the experimental work, though performed individually, is of such a nature as to warrant a unified description. In this way the reader is afforded a better representation and clearer conception of the problem, and a substantial guide for further investigation. Though much work has been done in the field of wax analysis, little is known of the higher fatty acids and alcohols of many of the waxes. Their isolation has been infrequent, and few if any of their derivatives have been formed. It …

Hardness And Porosity In Chromium Plating, Waldemar Wick

Bachelors’ Theses

In recent years chromium plating has been subjected to much research due to its ever-increasing demand. The results of these investigations have demonstrated the valuable properties of this plate. Of its many advantageous properties, hardness is one of the outstanding ones, but its application in industry is as yet not fully realized. This being due to the fact that it is difficult to produce a plate that is uniform and does not chip. Many chemists have investigated the porosity of the chromium plate in order to produce a coating that could be used for protective purposes, but there seems to …

The Study Of The Effects Of Different Metallic Soaps On The Water Content Of Water-In-Gasoline Emulsions, Lynn D. Wilson

Bachelors’ Theses

The study of emulsions and emulsification is of very great theoretical and practical interest. From the standpoint of pure science it throws much light on the problems of surface tension, surface concentration, absorption, surface films, electrical double layers. Brownian movement, and the general theory of disperse systems and colloids. It is also of importance in biological science, e.g., the adsorption of fats and the permeability of membranes. When industrial and applied science are considered, it is remarkable how many subjects of interest and importance are dependent on a knowledge of the formation, behavior, and stability of emulsions. In this connection, …

A Study Of Phytosterol Obtained From Cocoa Beans And Cocoa Butter, Norman Anthony Pokorny

Bachelors’ Theses

Despite the fact that considerable work has been done on cholesterol, relatively little is known about its isomer, phytosterol. Both cholesterol and phytosterol belong to the general group of sterols. Cholesterol is described as an aromatic sterol, a mono~atomic secondary alcohol, containing an iso-propyl and a vinyl group, with a terpene-like structure. Cholesterol was first discovered by Conradi in 1775, then by Gren (1788) in biliary calculi. In 1785 Fourcroy isolated cholesterol from gall-stones, one variety of which is composed almost wholly of it, but it was confused with adipocere, until Chevreul (1814) discovered its true nature, when he declared …