Chemistry Commons^™

Silica Based Solid Phase Extraction Sorbent With A Removable Alkyltrimethylammonium Surfactant Phase, Tony Oakes

Masters Theses & Specialist Projects

Presented is a solid phase extraction (SPE) sorbent having a removable "stationary phase." This removable phase that consists of alkyltrimethylammonium surfactant is initially immobilized onto hydrophilic strong cation exchange resin. The surfactant chain through hydrophobic interactions extracts hydrophobic analytes in the same manner as conventional bonded alkyl moieties on silica based non-polar sorbents. For the extraction of very hydrophobic species with conventional sorbents, solvents used for analyte elution are generally toxic and not directly instrument compatible. The chosen solvent must be strong enough to efficiently break hydrophobic interactions between the analyte and sorbent. Using a removable "stationary phase," hydrophobic interactions …

Investigation Of The Relationship Between Particulate Bound Mercury And Properties Of Fly Ash In A Full-Scale 100 Mwe Pulverized Coal Combustion Boiler, Sen Li

Masters Theses & Specialist Projects

There is an increasing concern over mercury emissions from coal-fired boilers. Coal-fired power generation accounts for approximately 33% of total mercury emission in the United States. Once it is emitted into the atmosphere and deposited on land or water, mercury can transform into methylmercury, an organic form. Mercury can then enter the food chain, which poses a potential threat to human health and the environment. To study the relationship between particulate bound mercury and fly ash properties, fly ash samples were collected from the mechanical hopper (MHP) and the electrostatic precipitator (ESP) of a 100 MWe pulverized coal-fired boiler and …

Direct Multielemental Analysis Of Solid Samples Using Laser Ablation Inductively Coupled Plasma Mass Spectometry And Pulsed Radio Frequency Glow Discharge Mass Spectrometry, Joseph Miller

Masters Theses & Specialist Projects

Direct solid sampling is an area of analytical research that has generated a large amount of interest in recent years. Two analysis systems offering fast and nondestructive methods of determining the elemental composition of substances, without requiring complicated sample preparation procedures, are laser ablation inductively coupled plasma mass spectroscopy (LA-ICPMS) and radio frequency glow discharge mass spectroscopy (rf-GDMS). A Cetac LSX-200 laser system coupled to a LECO Renaissance ICPMS was utilized to analyze coal and ash samples prepared by incorporation into a lithium borate matrix to form a disk. In addition, a VG 9000 Glow Discharge Mass Spectrometer (GDMS) with …

A 59-Cobalt Nmr Investigation Of The Hydrogen/Deuterium Exchange Kinetics In Cobalt(Iii) Complexes, Michelle Mccombs

Masters Theses & Specialist Projects

Currently, the hydrogen/deuterium exchange kinetics in cobalt(III) complexes are being investigated. In the presence of deuterated solvents, (e.g. D2 0 and CH3CH20D) the amine hydrogens in the complexes are exchanged for deuteriums. For the hexaamminecobalt(III) ion, 19 isotopmers (H18D0 to HOD 18) are possible. For the tris(ethylenediammine)cobalt(III) ion, 13 isotopmers (HI 2D0 to HOD 12) are possible. Each hydrogen/deuteruim exchange causes a shift in the observed 59Co resonance of approximately 6 ppm. The rate constant of the hydrogen-deuterium exchange for the first H-D exchange has been determined as a function of solvent. When the chosen solvent is D20, the rate …

Teachers' Resource For Materials And Environmental Chemistry, Carnetta Skipworth

Masters Theses & Specialist Projects

In many secondary education chemistry classrooms, teachers have a difficult time introducing chemistry topics in a way that will be interesting to the high school student. The development of a materials and environmental chemistry teacher's manual will help teachers introduce a variety of selected topics in an interesting fashion to the students. This manual focuses on the subjects covered for freshman and sophomore level students. The manual uses five separate experiments to introduce topics such as the electromagnetic spectrum and solubility. The five experiments include a test on tennis shoe stiffness and energy dissipation ability, pesticides in water, grease in …

Directed Ortho-Metalation Of Dimethylarylamines, Michael Timmons

Masters Theses & Specialist Projects

Site-specific product(s) from the reaction of benzene derivatives with various reagents is a need of researchers at numerous laboratories, particularly those in the pharmaceutical industry. Such derivatives can be synthesized directly, i.e., by substitution of a proton, using either of two procedures: electrophilic aromatic substitution (EAS) or directed ortho-metalation (DoM). Directed ortho-metalation (DoM) is an alternative aromatic substitution process initiated by organolithium reagents which provides regiospecific substitution exclusively at the ortho- position (equation). The focus of this study is to find hydrocarbon media that will permit the maximum extent of metalation of several dimethylarylamines. The dimethylamine-containing substituents constitute directing metalation …

Metalation Of The Di- And Tri-Methoxybenzenes, Phillip Shelton

Masters Theses & Specialist Projects

Hydrocarbon solvents are known to be unreactive towards organolithium reagents and also to afford little support for ortho-metalation reactions. In contrast, both m- and odimethoxybenzene afford 80% "ion-multiple specific" monometalation in hydrocarbon solvent (n-hexane, cyclohexane, toluene) without the addition of any catalyst (ether or amine). These observations are, in part, attributed to the 1,2- and 1,3- formation of the n-BuLi dimer, the most reactive form of n-BuLi. In other words these substrates are acting in a "substrate-catalyzed" manner. Extensions of these concepts to 1,2,3-, 1,2,4- and 1,3,5-trimethoxybenzenes have led to further unusual observations. In particular, the 1,2,3-system affords an interesting …

Study Of Polyaromatic Hydrocarbons Emitted In The Fly Ash From Coal Combustion In A Fluidized Bed Combuster, Rebecca Heltsley

Masters Theses & Specialist Projects

Exposure to Polyaromatic Hydrocarbons (PAHs) has long been identified as an environmental concern because of their carcinogenic and mutagenic effects. The Environmental Protection Agency (EPA) has developed a list of 16 PAHs that are found on the Priority Pollutant List due to the extensive amount of data suggesting the hazards of these compounds. These toxic compounds are often emitted into the atmosphere by anthropogenic sources, such as combustors. Therefore, analysis of these compounds must be conducted during coal combustion. Two 1000-hour coal combustion burns were performed using the 0.1 MWth bench-scale fluidized bed combustor (FBC), which is found in the …

Development Of Bismaleimide/Cyanate Ester Based Aerospace Polymers For Possible Use In Nasa's Relaunchable Vehicles Program, Brian Sisk

Masters Theses & Specialist Projects

Since the beginning of the space age, the goal of materials development in the aerospace industry has been to replace metal alloys with much lighter polymer resins, while maintaining the strength over a wide temperature range characteristic of metals. Polymers such as polyimides and epoxies have been used to satisfy many needs, but strength, temperature resistance, and ease of processing are difficult to incorporate into a single polymer. Because of this gap, bismaleimides and cyanate esters, and possibly combinations of the two, are seen as having potential in applications where ease of processing characteristic of epoxies is desired, but for …

Studies Of Sulfur Reduction Of Taurine And Taurine-Conjugated Bile Acids By Bile Acid 7Α-Dehydroxylating Bacteria, Jiang Qian

Masters Theses & Specialist Projects

Bile acids are C24 steroids that are derived in the liver from cholesterol and secreted into the intestinal lumen to aid in emulsification of dietary lipids and lipid-soluble vitamins. The indigenous intestinal microflora modify bile acids, producing up to 20 unique bile acid metabolites. The 7α-dehydroxylation of the bile acids is the most physiologically important bile acid biotransformation. All known intestinal bacteria capable of bile acid 7α-dehydroxylation are anaerobic, gram-positive rods of the genera Clostridium and Eubcicterium. Bile acid 7α-dehydroxylating bacteria often contain bile salt hydrolase, which hydrolyzes the peptide bond in taurine-conjugated bile acids to yield a free bile …

Enantioseparation Of Alkylaryl Sulfoxides Using Capillary Zone Electrophoresis, Chad Snyder

Masters Theses & Specialist Projects

Alkylaryl sulfoxides possess a chiral sulfur atom easily identifiable by capillary zone electrophoresis (CZE). Separation of chiral alkylaryl sulfoxides has already been accomplished by modified method of CZE known as micellar electrokinetic chromatography (MEKC). However, no articles have been published on the enantioseparation of alkylaryl sulfoxides using capillary zone electrophoresis.

A series of sulfoxides were synthesized, purified and identified via NMR. Enantioseparation was performed using CZE employing a 10 mmol. Phosphate buffer (pH 4.0, 25% acetonitrile, 2% sulfated-β-cyclodextrin). Synthesis of these sulfoxides will be presented along with the results of the procedure’s optimization. Separation of the sulfoxide enanitomers relies on …

A Study Of The Thermal Properties Of Peti-5/Im7, Yan Tang

Masters Theses & Specialist Projects

PETI-5 (Phenylethynyl-terminated polyimide) is a substance that shows a great deal of potential in the high-speed aircraft and the aerospace industry. PETI-5 has been used for the High Speed Civil Transport (HSCT), a supersonic passenger aircraft in development at NASA. In this project, four staging samples, one fresh sample, one fully cured sample and one partially cured sample were analyzed and compared using thermal analytical techniques. The sample staged at 450°F with full vacuum showed the highest thermal properties among four staging samples. The results indicated that vacuum is helpful in improving the thermal stability of PETI-5. The mechanism of …

Analysis Of Galvanized Steel Plates Using Glow Discharge-Atomic Emission Spectrometry, Liang Wang

Masters Theses & Specialist Projects

Combining an intense emission source and a high-speed sputtering source in one, glow discharge atomic emission spectrometer (GD-AES) provides an efficient technique for analyzing surfaces, coatings and bulk solids. The purpose of our work is to explore the optimum lamp operation parameters of SA-2000 for analysis of galvanized steel plate and to investigate the method for qualitatively and quantitatively analyzing the zinc coating. Under the optimum experimental conditions found in our study, which are current of 19-21 mA; voltage of 900-1200 V; pressure 2.0-2.5 torr, the calibration curve is constructed, so that specific zinc concentration can be assign to the …

Comparison Of An Advanced Mercury Analyzer With The Cold Vapor Atomic Absorption Technique For The Determination Of Mercury In Coal, Dong Li

Masters Theses & Specialist Projects

For over 30 years the industry standard method for mercury analysis has been the cold vapor atomic absorption spectrometric technique (CVAAS). Recent developments in improving this technique have focused on procedures for concentrating mercury in the analyte or materials to improve detection. The LECO Corporation produces an Advanced Mercury Analyzer, the AMA-254, for analysis of the solid and liquid samples. The system allows for the thermal heating of the sample to decompose the sample and release mercury, which is concentrated in a gold amalgam. Thermal desorption of the mercury from the amalgam is detected by atomic absorption spectroscopy. A comparison …

An Immobolized Surfactant Extraction Technique Compatible With High Performance Liquid Chromatography-Ultraviolet Visible Detection, Ming Zhu

Masters Theses & Specialist Projects

Surfactant mediated extractions are analogous to liquid-liquid extractions (LLE) except surfactants are used as extractants instead of organic solvents. The benefit for using surfactants for extractions includes lower toxicity, lower associated costs and direct compatibility with high performance liquid chromatography techniques. In this study, a novel immobilized surfactant extraction method was developed. In this method, the cationic alklytrimethylamrnonium surfactants are immobilized onto a strong cationic exchange resin through ion exchange. This surfactant-resin material is placed in a column and aqueous solutions containing analytes are passed through. The analytes are retained by the long carbon chain of the surfactant molecules and …

Analysis Of Fats And Fat-Soluble Components In Foods Using Supercritical Fluid Extraction And Chromatographic Techniques, Sneha Patel

Masters Theses & Specialist Projects

The purpose of this study was to develop experimental procedures for the extraction of fats from common foods using SFE and to determine by chromatographic techniques the fat-soluble components that are extracted with the fats. In this study various food samples were examined including french fries from Wendy's, McDonald's and Burger King, as well as potato chips, peanut butter and donuts. Soxtec extraction was used as the standard method for comparison of results (percentage of fat) obtained from SFE. Gas chromatography and gas chromatography/mass spectrometry were used for the determination of fat-soluble components (fatty acids), after extraction of fat from …

An On-Line Test For Polycyclic Aromatic Hydrocarbons In The Flue Gas From Coal Combustion In An Fbc System, Wenjun Han

Masters Theses & Specialist Projects

Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants that have received considerable attention because of their carcinogenic and mutagenic effects. Due to the extensive amount of data suggesting the hazards of these compounds, 16 PAHs are on the Environmental Protection Agency (EPA) Priority Pollutant List. These compounds are often emitted into the atmosphere by way of combustion processes. Thus, analysis of these compounds during coal combustion is an important task. Three 1000-hour coal combustion burns were performed using the 0.1 MW (0.3 m) bench-scale Fluidized Bed Combustor (FBC) in the Combustion Laboratory at Western Kentucky University. The data for this thesis …

Capillary Zone Electrophoresis Studies Of Sulfur Containing Compounds, Francisco Rodriguez

Masters Theses & Specialist Projects

Up to this point in time, complex mixtures of tertiary sulfonium ions have been separated or analyzed employing conventional methods like HPLC or NMR procedures. In this thesis the researcher presents a new approach, the use of Capillary Zone Electrophoresis (CZE) for the analysis of these types of ions as well as the closely related thiophenium ions. CZE offers an unprecedented advantage in that separations can be employed for speciation or quantitation of complex mixtures by using the appropriate standards or specific detectors. For the study, model sulfonium and thiophenium ions were used to determine the feasibility of the separation …

Capillary Electrophoretic Separation Of Sulfoxides, Clair Davies

Masters Theses & Specialist Projects

Chiral sulfoxides are most widely used in asymmetric synthesis. Their application as chiral synthons has now become a well-established and reliable strategy, mainly due to availability and high asymmetric induction exerted by the chiral sulfinyl group. Very few articles have been published on the separation of chiral sulfoxides; most involve HPLC or GC. The first separation of optically active sulfoxides was described by Phillips and co-workers. To date no work has been reported using capillary electrophoresis for the separation of alkylaryl sulfoxides. A series of alkylaryl sulfoxides were synthesized. Conditions for their separation were investigated using a modified 125 mM …

A Study Of High Temperature Corrosion In An Afbc System, Wie Xie

Masters Theses & Specialist Projects

The occurrence of furnace wall and superheater corrosion in fluidized bed combustor systems has caused some operational and economic concerns. It is generally accepted that chlorine and sulfur may play roles in this corrosion. In order to predict the performance of high chlorine or high sulfur coals in these combustion systems, it is necessary to have a better understanding of the different corrosion mechanisms in which chlorine and sulfur may be involved. It is also important to evaluate the critical point of coal chlorine content which may cause initial corrosion. The laboratory-sized atmospheric bed combustor (AFBC) at Western Kentucky University …

The Effects Of So2 On The Formation Of Cl2 During Co-Firing Muncipal Solid Waste With Coal, Ying Xie

Masters Theses & Specialist Projects

The Deacon Reaction was proposed as a mechanism for the formation of molecular chlorine during the combustion of municipal solid waste (MSW): 4HCl + O2 ↔ 2Cl2 + 2H2O As suggested by some researchers, co-firing high sulfur coal with MSW may reduce the emission of toxic chlorinated organics, resulting from the reaction between S02 and Cl2: SO2 + Cl2 + H2O → SO3 + 2HCl The effect of sulfur dioxide on the formation of chlorine through the Deacon Reaction is investigated in this study. A Lindberg Furnace was utilized and preheated to 800°C to simulate the conditions in the AFBC …

Forensic Soil Analysis: Characterization Of The Sand Fraction, John Baize

Masters Theses & Specialist Projects

The purpose of this project was to develop a comprehensive analytical method for the characterization of soil by examining particle size, elemental composition, and percent organic matter in soil, and to determine its forensic applicability. In this study, five soils of varying geological locations were examined including two samples from Kentucky; two samples from Pennsylvania; and one from Washington D C A Gilson sonic sieve shaker was used to separate fractions of soil to determine particle size, and a JEOL scanning electron microscope with a Kevex EDS detector was used to determine elemental composition. These techniques coupled with percent total …

Development Of An Atmospheric Fluidized Bed Combustor (Afbc), William Orndorff

Masters Theses & Specialist Projects

The relatively recent interest in the U.S. in the development of atmospheric fluidized bed combustion (AFBC) has been preceded by two main factors. First of these is the ever present problem of acid rain and growing public support for cleaner burning fossil fuels. Second is the increasing demand on public landfills and subsequent need for burning of municipal solid waste. From these factors and their corresponding influences, Western Kentucky University has the impetus and has received the financial assistance necessary to build and develop a laboratory scale AFBC system. A brief history of the events leading to this development, as …

Studies On Resolution Of Enantiomeric Dialkylaryl Sulfonium Ions With Nmr Shift Reagents, Ea-Ji-Ru Son

Masters Theses & Specialist Projects

Praseodymium(III) NMR shift reagent, which is an upfield shift reagent, is focused on for assessment of enantiomeric excess and resolution of methyl sulfonium ions. A series of alkylmethylphenylsulfonium ions were analyzed, where alkyl is ethyl (I), butyl(H), octyl (III), and benzyl(IY). The praseodymium agent gives base-lined resolution of the ortho hydrogens resonance for I and IH. All spectra are strongly temperature-dependent. I is shifted more than ED, consistent with a steric effect. Assignments for I were made by gradually increasing the concentration of the shift reagent and by analyzing R-enriched I. Racemization of R-enriched isomer of I by pyramidal inversion …

A Study Of Polycyclic Aromatic Hydrocarbons During Combustion In An Afbc System, Laura Dicken

Masters Theses & Specialist Projects

The purpose of this study was to develop the on-line method of analysis which leads to the study of polycyclic aromatic hydrocarbons (PAHs) during combustion in an atmospheric fluidized bed combustor (AFBC) system. The study of PAHs is important because they may be produced upon the combustion of coal. The US EPA prioritizes PAHs as major pollutants due to their mutagenic and carcinogenic effects. Standards of PAHs were analyzed by injection into the gas chromatograph-mass spectrometer (GC-MS). These standards were then analyzed using the on-line method. Two coals were burned in the AFBC system and effluent samples were collected. These …

Fundamental Investigations Of Mechanistic Pathways Of Selected Organic Reactive Intermediates, Carl Whittle

Masters Theses & Specialist Projects

Part 1 of this thesis deals with the role that it -electron density plays in the formation of it -complexes in electrophilic aromatic substitution. Using commercial and synthetic compounds of varying it-electron density, the fact that % -complexes actually exist in these species was determined by a mass spectral investigation that was designed to monitor alkyl side-chain isomerizaitons. Also, the amount of it-complex was determined for each compound by measuring the amount of alkyl carbenium ion loss in each compound's mass spectrum. Found within the systems was an internal trend showing that the greater the amount of 7t-electron density in …

A Study Of The Volatile Matter Of Coal As A Function Of The Heating Rate, Enrique Santos

Masters Theses & Specialist Projects

A study of volatile matter yields as a function of the heating rate was conducted. A suite of 21 coal and coke samples varying in rank from anthracitic to lignitic and heating rates from 10°C/min to about 450°C/min were used in the study. Heating rates up to 60°C per minute, which are typically used in ASTM Test Method 5142 (instrumental Proximate Analysis), were achieved in a macro thermogravimetric analysis (TGA) system. Heating rates of 50-200°C/min were obtained in a micro TGA system. All measurements were made in a nitrogen atmosphere. The results of the study illustrate the dependance of the …

Development Of Methods For The Determination Of Major And Minor Elements And Hydrocarbon Residues In Solid Combustion Products, Xiaoliu Chi

Masters Theses & Specialist Projects

Methods for the determination of inorganic constituents in coal fly ash by glow discharge spectrometry (GDS) and for the extraction of the organic compounds from coal and ash by supercritical fluid extraction (SFE) at temperatures below 150°C are reviewed. The inorganic elements studied included Al, Ca, C, Cu, Fe, Mg, Mn, P, S, Si and Ti. The organic compounds were measured by weight loss of the sample. The goal of this research was to find easier and faster ways to measure the concentration of inorganic elements in coal ash and to measure extractability of the coal itself, to make coal …

A Study Of Combustion Profiles Of Co-Fired Coal/Biomass/Limestone Samples In A Fluidized Bed Combustor, Beverly Campbell

Masters Theses & Specialist Projects

Concerns over declining landfill space and a renewed interest in waste-toenergy technologies have increased the possibilities of co-firing different types of fuels in atmospheric fluidized bed combustion systems. The laboratory sized atmospheric fluidized bed combustor (AFBC) at Western Kentucky University was designed to serve as a highly flexible research and development facility to gain operating experience, evaluate combustion performance, and estimate the effect of flue gas emissions on the atmosphere. The operating conditions for the AFBC system are similar to those used at the TVA 160-MW AFBC Pilot Plant located near Paducah, Kentucky. AFBC systems are ideal for co-firing because …

Mass Balance Of Major, Minor And Trace Elements During Afbc Combustion Of Fuels, Qianwen Cao

Masters Theses & Specialist Projects

The proposed ASTM procedures for the determination of 13 major and minor., and 11 trace elements, in solid coal and coke combustion residues by inductively coupled plasma-atomic emission spectrometry (ICP-AES) were checked for routine use. In this study, the ICP analysis values and XRF analysis values of major and minor elements in two kinds of coal and two kinds of limestone were compared. It was shown that over 95% closure of the mass balances of the 24 major, minor, and trace elements was obtained with the proposed ASTM procedure. Also, it was demonstrated that trace elements may be lost through …