PhD, University of Cincinnati, 2017, Arts and Sciences: Chemistry

A considerable number of dietary supplements suspected of containing phosphodiesterase-5 (PDE-5) inhibitors and substituted phenethylamines have been analyzed by the U.S. Food and Drug Administration. Often these samples are found to contain the active pharmaceutical ingredients (API) such as sildenafil or phentermine, and in many cases, products contain multiple PDE-5 inhibitors or substituted phenethylamines. In an analytical setting, it is important to confirm the presence of any API with two or more independent methods, and this requirement can often put undo strain on a laboratory. The development and use of methods that inherently contain two unique identification techniques is preferred, and the creation and validation of three of those methods is outlined here. First, direct deposit Fourier transform infrared detection and mass spectrometric detection (GC/FT-IR/MS) is used to identify PDE-5 inhibitors. Generally, GC/MS is not generally used for this category of drugs due to low volatility; PDE-5 inhibitors often co-elute and can produce non-specific electron ionization fragmentation patterns. In contrast, FT-IR has been proven to be more selective for identifying PDE-5 inhibitors, but is generally not as sensitive as spectrometric techniques. However, it has been shown that each technique can compensate for the other, which allows a wider range of usability. Using this combined technique can save time and resources while still delivering a high level of certainty in identification by providing results from two scientifically uncorrelated techniques. Multiple reference standards were utilized for method validation, including determination of linearity, dynamic range, and limit of detection. Second, a single HPLC-UV method has been developed for the determination of PDE-5 inhibitors and related analogs in pharmaceutical dosage forms and dietary supplement products. Using this protocol, 14 PDE-5 inhibitor compounds can be separated and determined in a single an (open full item for complete abstract)

Committee: Peng Zhang Ph.D. (Committee Chair); Anna Gudmundsdottir Ph.D. (Committee Member); Laura Sagle Ph.D. (Committee Member) Subjects: Chemistry

Doctor of Philosophy, Miami University, 2013, Chemistry and Biochemistry

This dissertation describes the development and application of methods and instrumentation for qualitative and quantitative sample analyses by infrared and Raman spectroscopies. An introduction to the concepts and methods utilized is provided in Chapter 1. A comparative evaluation of solid-core silver halide fiber optics and hollow silica waveguides was performed on the basis of the transmission of mid-infrared radiation using a fiber optic coupling accessory and an infrared microscope is presented in Chapter 2. Increased transmission was reproducibly observed between two identical hollow waveguides due to minimization of insertion and scattering losses resulting from the hollow core. Chapter 3 presents an evaluation of a mid-infrared, attenuated total (internal) reflection (ATR) probe accessory utilizing hollow waveguides based on transmission and signal-to-noise. Quantitative analyses of aqueous succinylcholine chloride and ethanol solutions were also performed. An in situ Raman study of nitrogen incorporation in thin films of zinc oxide using a temperature-controlled reaction cell is discussed in Chapter 4. Monitoring nitrogen incorporation in thin films of zinc oxide at elevated temperatures in the presence of nitrogen-containing precursor reagents proved inconclusive using the proposed method. Chapter 5 presents an evaluation of dispersive and Fourier transform (FT-) Raman spectroscopies for on-line process control in the bottling industry. FT-Raman was determined to be more applicable for on-line determinations of poly(ethylene terephthalate) bottle thickness due to the availabilities of such benefits as increased laser power and fluorescence rejection. Preliminary data from the development of an inverted ATR imaging microscope are discussed in Chapter 6. The inverted optical design of the microscope permits simultaneous viewing of the sample with white light and the collection of infrared spectral images. Summaries of the presented research are pro (open full item for complete abstract)

Committee: André Sommer PhD (Advisor); Neil Danielson PhD (Committee Chair); Jonathan Scaffidi PhD (Committee Member); David Oertel PhD (Committee Member); Lei Kerr PhD (Committee Member) Subjects: Analytical Chemistry; Chemistry

Doctor of Philosophy, Miami University, 2010, Chemistry and Biochemistry

This dissertation describes the use of infrared and Raman microspectroscopic methods for the analysis of small mineral inclusions in kidney biopsies and efforts to quantitatively analyze components at the localized mineral/tissue interface. Chapter 1 provides a background on the current state of kidney stone disease research and also describes the instrumental methods utilized. Chapter 2 presents the use of attenuated total internal reflection (ATR) infrared spectroscopy to generate calibration curves for mixtures of powdered kidney stone components. This study demonstrates that reproducible quantitation can be achieved if the particle sizes of the components are small and comparable. ATR imaging was employed to analyze kidney biopsies with small mineral inclusions in Chapter 3. ATR imaging has several benefits over other infrared sampling methods (primarily transflection and transmission) for the analysis of kidney biopsies due to the smaller focused beam size achievable and the reduced optical pathlength that eliminates spectral artifacts. Chapter 4 describes an investigation into small particle analysis with transmission infrared microspectroscopy and ATR imaging. The results of the study show that spectral artifacts are dependent on the particle's size and shape and it is anticipated that this research will provide a framework for the analysis of particles below the diffraction limit. Chapter 5 presents a comparative study of Raman microspectroscopy and ATR imaging for kidney biopsy analysis. Using both methods in unison allows the investigator to obtain a full spectroscopic picture of the sample. Because Raman interrogates a larger, more uncontrolled sample volume, ATR may be more beneficial for quantitative studies. Chapter 6 summarizes the presented research and discusses future work.

Committee: Andre J. Sommer PhD (Advisor); Neil D. Danielson PhD (Committee Chair); Andrew P. Evan PhD (Committee Member); Thomas L. Riechel PhD (Committee Member); Lei L. Kerr PhD (Committee Member) Subjects: Analytical Chemistry

Master of Science, The Ohio State University, 2009, Food Science and Nutrition

Fourier-Transform infrared (FT-IR) spectroscopy is a simple, fast and highly specific technology that can provide valuable insights into the complex chemical make-up of foods. Infrared provides tools, especially in the fingerprint region of the spectrum, to detect specific compounds in biological systems without the use of time-consuming methods or the use of hazardous organic solvents. Advances in FT-IR instrumentation and pattern recognition techniques have made it possible to extract information related to composition and conformation of food components from the spectra. We have evaluated the capability of infrared spectroscopy in classification and quantification of chemical compounds of interest for the dairy (butter) and tomato industries. Authentication is a critical quality issue for organic products since consumers are willing to pay 10-40% price premiums. There is a need for rapid and reliable analytical tools for determination of authenticity since traditional methods often involve time-consuming and laborious processes. Our objective was to evaluate the application of infrared spectroscopy combined with pattern recognition techniques to discriminate among organically and conventionally-produced butter in relation to quality and authenticity. Spectra from butter purchased from a local market (Columbus, OH) were collected by using Attenuated total reflectance (ATR) spectroscopy and analyzed using soft independent modeling of class analogy (SIMCA), a multivariate classification technique. This simple protocol generated unique mid-infrared signature profiles that permitted the chemically-based classification of butter samples based on manufacturer and production practice (organic vs. conventional). By using the spectral region from 1400-800 cm-1, multivariate (SIMCA) modeling showed well-separated clusters that discriminated among butter samples according to manufacturer, due to -HC=CH- trans bending out of plane vibration modes, (966 cm-1) presumably attrib (open full item for complete abstract)

Committee: Luis Rodriguez-Saona PhD (Advisor); Jeff Culbertson PhD (Committee Member); David Min PhD (Committee Member) Subjects: Food Science

Master of Science (MS), Ohio University, 2023, Civil Engineering (Engineering and Technology)

Tire particles (TP) are the largest source of microplastics in nature. However, the adsorption behavior of TP needs to be better understood. TP used in this study were generated from cryo-milling and aged with 30% nitric acid. Single and competitive adsorption isotherm experiments were conducted to investigate the potential of TP as carriers of heavy metals. Langmuir and Freundlich models were used to analyze adsorption data. Competitive adsorption demonstrated a reduction in the adsorption capacity of TP. The preference for lead to copper by TP was explained by the physical and chemical properties of the metals. The adsorption capacity was maximum at the pH range of 6-12 for lead, and for copper, it was pH 10. pH, zeta potential, FT-IR, and XPS results indicated that electrostatic attraction and surface complexation were involved in the heavy metal adsorption on TP.

Committee: Lei Wu Dr. (Advisor); Natalie Kruse-Daniels Dr. (Committee Member); Daniel Che Dr. (Committee Member); Guy Riefler Dr. (Committee Member) Subjects: Environmental Engineering

Master of Science (M.S.), University of Dayton, 2020, Chemical Engineering

The use of cost-effective bio-based materials, such as lignin, offers the potential to replace commercially available, expensive synthetic petroleum materials which are currently used in the production of fibers and plastics. Many lignin-based nano-scale fibers have the potential to be used in a vast range of applications, ranging from automobiles to the electronics industry. These nanofibers can also be used in chemical separations and adsorption technologies. Unfortunately, lignin possesses a low molecular weight, and therefore polymer blends are used for the production of lignin-based nanofibers. Hence there is a need to optimize and understand polymer-polymer interactions of lignin and a carrier polymer to ultimately generate nanofibers with desired characteristics. In this study, two types of lignin, low sulfonate (LSL) and alkali, kraft lignin (AL) were investigated and combined with polyacrylonitrile-co-methyl acrylate (PAN-MA) for the fabrication of nanofibers using electrospinning techniques. The polymers were solubilized in N,N dimethylformamide (DMF) and prepared at different PAN-MA:lignin ratios ranging from 100:0 to 50:50 at varying total polymer concentrations ranging from 10 wt % to 20 wt %. Using solvent evaporation, PAN-MA/lignin films were obtained and the polymer arrangements, phase separation, and morphology were studied via polarized optical microscope (POM) and scanning electron microscopy (SEM). AL blends showed good miscibility with PAN-MA at higher concentrations wherein LSL blends found to have phase separation. Rheological characterization of LSL and AL in PAN-MA polymer solutions included flow sweep, frequency sweep, and amplitude sweep tests, which were used to gain insights into the effects of lignin type and ratios in the polymer solutions. Electrospinning of various PAN-MA/lignin solutions proceeded at an operating voltage of 15 kV with currents varying between 0-2 µA and at a 0.003 ml/min constant flow rate. Thermal and chem (open full item for complete abstract)

Committee: Erick Vasquez Dr. (Committee Chair); Donald Klosterman Dr. (Committee Member); Kenya Crosson Dr. (Committee Member) Subjects: Automotive Engineering; Chemical Engineering; Chemistry; Environmental Engineering; Materials Science; Nanotechnology; Polymers; Sustainability

Master of Science, University of Akron, 2020, Polymer Science

Melanin is a ubiquitous pigment found in animals, plants, and microorganisms, which is widely known for its UV light absorption capacity, high antioxidant activity, and other unique properties. The most common commercial sources are synthetic melanin: polydopamine (PDA) and poly(L-3,4-dihydroxyphenylalanine) (PDOPA), and natural melanin: sepia melanin. Here, we extract melanin from black knot fungus (Apiosporina morbosa), a pathogenic fungus that grows on several fruit trees, using acid/base extraction method and elucidate the chemical structure of the extracted melanin by Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (ssNMR) spectroscopy. The extraction yield is around 10% and the characterization results prove that its chemical structure is similar to synthetic melanin, PDA and PDOPA, which illustrates that the extracted melanin is eumelanin. Scanning electron microscopy (SEM) images show irregular morphology of melanin. Also, the extracted melanin shows a broadband UV light absorption similar to melanin extracted from other sources. Because of the low cost of black knot fungus and it being an invasive species, it can serve as a cheaper alternative source of melanin, which could be applied as UV light absorbers and antioxidant reagents in the future.

Committee: Ali Dhinojwala (Advisor); Toshikazu Miyoshi (Committee Member) Subjects: Chemical Engineering; Polymers

Master of Science (M.S.), University of Dayton, 2018, Materials Engineering

The research described herein examines the effect of hydrolytic decomposition on the work function of polyurethane rain erosion coatings (REC). Two groups of panels, one group coated with REC containing carbon black and one group coated in REC without carbon black, were exposed to high temperature and humidity conditions in a steam autoclave for various periods of time. The work function of each unique exposure time was measured with a scanning Kelvin probe (SKP) and compared to unexposed coated panels to determine the magnitude of change in the REC coating. For both sample groups, results from the SKP analysis showed that as the coated panels were exposed for longer periods of time, the work function increased compared to an identical panel that was not exposed. The extent of the polymer coating degradation was determined by Raman spectroscopy and thermomechanical analysis (TMA). Raman analysis indicated a decrease in ester bonds, while with TMA a decrease in polymer strength was observed with increasing exposure time. These results demonstrate that there is decomposition of the REC occurring from the exposure and it is due to hydrolysis of the ester bonds. The change in REC structure/composition was able to be detected by the Kelvin probe in a non-destructive manner, making it a valuable tool in assessing the decomposition of polyurethane rain erosion coatings.

Committee: Douglas Hansen Ph D. (Advisor) Subjects: Aerospace Materials; Materials Science; Polymer Chemistry

Master of Sciences (Engineering), Case Western Reserve University, 2018, Materials Science and Engineering

Properties of structural alloys containing chromium, for example 316L austenitic stainless steel, can be tremendously improved by surface engineering through infusion of interstitial solute, including carbon or nitrogen. However, to make the surface transparent to carbon or nitrogen, it must be “activated”. A potent method that has recently been discovered for such “surface activation” is exposing the alloy to the gaseous products of a pyrolyzed solid reagent. For this purpose, pyrolysis of nitrogen-halide salts with 316L samples has been demonstrated to be highly effective, but the micromechanisms of activation have been elusive. In this thesis project, pyrolysis FT-IR has been used to examine the products of pyrolyzing various solid reagents in an effort to model surface reactions. This work has demonstrated that ammonia and hydrogen chloride evolving from NH4Cl are responsible for reducing the surface oxide and forming chlorides and nitrides in the 316L surface. A new approach has been used to characterize the activated surface: ToF-SIMS paired with isotope-rich solid reagents. This enables observation of transport phenomena and determine surface reaction products. Considerable progress has been made on hybrid-processing (activation separated from infusion) of parts in an industrial capacity. A model has been developed to explain the micromechanisms of activation for low-temperature carburization. Understanding the chemical reactions and microstructural changes occurring during this process is vital for developing more rapid and effective low-temperature surface hardening technologies. One main conclusion of this work is that activation is not simply the reduction of protective surface oxides, but actually the formation of a 3 to 7 micrometer thick layer of chlorides and nitrides in the substrate surface. Also, activation appears to be aided by condensation of pyrolysis products on the fresh surface protecting the newly oxide-free surface from passivation. (open full item for complete abstract)

Committee: Frank Ernst (Committee Chair); Arthur Heuer (Committee Member); John Lewandowski (Committee Member); David Matthiesen (Committee Member) Subjects: Engineering; Materials Science

Master of Science, The Ohio State University, 2013, Food Science and Technology

The application of infrared spectroscopy techniques to problems in the food and beverage industry has yielded many novel methods. With the increase in computational power, multivariate analysis has brought the unique properties of mid-infrared (MIR) systems to the forefront. The distinct, high intensity MIR absorption bands are well-suited to authentication, classification and quantification of components in complex matrices. This technique has been applied to a variety of food systems, with particular success in the analysis of edible oils. Methods for trans-fat determination, monitoring of oxidative indices, and discrimination of adulterated oils represent only a few of the developments in field of oils. The objective of this study was to utilize MIR spectroscopy in the analysis and characterization of products and processes related to edible oils. A temperature-controlled, ZnSe ATR sampling accessory was used with a benchtop FT-IR system to monitor oxidative changes in frying oils under the influence of a patented anti-oxidation device. In addition, reference methods for free fatty acids (FFA), anisidine value (AV), and color were used to monitor oil stability. FT-IR combined with chemometrics showed differences between control and treatment, with discrimination provided by regions associated with fatty acid hydrolysis and oxidation products. As compared to the control treatment, the anti-oxidation technology decreased the rate of FFA and aldehyde formation, as well as showing a marked effect on total color difference (¿E). Overall, our results showed that a patented induction device slows the rate of lipid degradation, resulting 7-20% reduction in formation rate of key quality parameters and significantly longer utilization of frying oil. Omega-3 dietary supplements have been linked with health benefits due to their contents of EPA and DHA. The concentration of these active components in fish is highly variable; species, catch location, environment, season and p (open full item for complete abstract)

Committee: Luis Rodriguez-Saona Dr (Advisor); John Litchfield Dr (Committee Member); Michael Mangino Dr (Committee Member) Subjects: Food Science

Master of Science (MS), Wright State University, 2008, Chemistry

A series of 1,3-di-substituted-imidazolium lithium phthalocyanines, in which the substituents on the imidazolium nitrogens were combinations of methyl, ethyl, pentyl, hexyl, isopropyl, adamantyl or 2,4,6-trimethylphenyl groups, was synthesized. The cation exchange of a single lithium ion of dilithium phthalocyanine for a 1,3-disubstituted-imidazolium ion was performed by mixing their salts in common organic solvents under ambient conditions. This afforded a number of imidazolium lithium phthalocyanines in moderate yields. They exhibited poor solubility in most solvents. Their composition and purity were initially verified by 1H and 13C-NMR and elemental analysis. The 1H-NMR spectra also indicated that the imidazolium and lithium phthalocyanine ions are present in a 1:1 ratio. Infrared spectra confirmed the C-C and C-N stretching modes that are characteristic of phthalocyanine and imidazolium aromatic structures. UV-Vis spectra for each compound showed essentially no change in absorption from that of dilithium phthalocyanine, which suggests a lack of influence of the imidazolium ions. Thermal properties of the title compounds were determined through melting points and TGA, in which high melting temperatures (330-370°C) were seen for several complexes and lowered thermal stability was seen for all. The crystal structure of the bis(adamantyl)imidazolium derivative was determined through X-ray diffraction. It was found that water molecules are associated to imidazolium and lithium phthalocyanine ions through hydrogen-bonding, which is possibly the basis for crystallization in imidazolium-lithium-phthalocyanines.

Committee: William Feld PhD (Advisor); David Grossie PhD (Committee Member); David Dolson PhD (Committee Member); Kenneth Turnbull PhD (Other); Joseph F. Thomas, Jr. PhD (Other) Subjects: Chemistry

Master of Science, The Ohio State University, 2009, Food Science and Nutrition

Concord grape juice is an especially valuable fruit juice due to its unique composition, sensory sttributes, and health benefits. Currently, methods of authentication are impractical at production scale. We propose Fourier-Transform Infrared spectroscopy in combination with chemometric analysis as a rapid means of authenticating Concord grape juice. Authentic grape juice samples were used as training sets to create SIMCA and PLS models capable of qualitative and quantiavie analysis respectively. The SIMCA model was effective at discriminating pure 100% juices on the basis of variety and capable of predicting the varieties of unknown samples. The PLS model was capable of predicting the content of Concord grape juice in a grape juice blend with an associated error of 8.4%. These simple models show the feasibility of FT-IR coupled with chemometrics as production scale tools for Concord grape juice authentication.

Committee: Dr. M. Monica Giusti PhD (Advisor); Dr. Sherryl A. Barringer PhD (Committee Member); Dr. David B. Min PhD (Committee Member) Subjects: Food Science

Doctor of Philosophy (PhD), Ohio University, 2004, Chemistry (Arts and Sciences)

Passive Fourier transform infrared (FT-IR) spectrometry has been used for a variety of automated remote sensing applications. The automated detection of target analytes can be implemented by classification algorithms trained with short segments of spectra or interferograms. Measurement settings for remote sensing applications based on passive FT-IR spectrometry are quite flexible because of the compact and rugged instrumentation. With airborne platforms, the applications of passive FT-IR spectrometry can be extended to large area monitoring of gases released from the sites of chemical incidents or volcanoes. For a successful airborne remote sensing application, it is impractical to perform costly and labor intensive airborne data collection to acquire large amounts of data required for training classification algorithms that implement the automated detection of the target analytes. It is highly desirable to collect training data under controlled conditions in the laboratory or during relatively low-cost experiments in the field and then apply the classifier trained with such data to airborne data classifications. The development of classification algorithms that are robust to differences between the training data and the data to which the classifier will ultimately be applied requires effective background suppression strategies. In this dissertation, data analysis strategies are sought that allow us to train classification algorithms for the automated detection of analytes without requiring costly and labor intensive airborne data collection. Support vector machines (SVMs) are employed as a method to implement robust classifications with short segments of filtered interferogram points as input patterns. Classifiers based on SVMs compare favorably with those based on piecewise linear discriminant analysis that have been successfully applied to various remote sensing applications. Digital filtering implementations are explored to improve the performance of background (open full item for complete abstract)

Committee: Gary Small (Advisor) Subjects:

Doctor of Philosophy, Case Western Reserve University, 1991, Macromolecular Science

Infrared spectroscopy was used to study the photooxidation of styrene-acrylonitrile (SAN) samples that were exposed to ultraviolet radiation having a minimum wavelength of 295 nm. It was determined that the photooxidation of SAN occurs exclusively at the styrene repeat units within the copolymer structure. The major infrared spectral changes resulting from the degradation process involve the appearance of new peaks within the hydroxyl and carbonyl regions. Using factor analysis results, it was concluded that there are a minimum of four different types of hydroxyl groups and three different types of carbonyl groups formed during the photooxidation of SAN. Furthermore, it was found that after 200 hours exposure the rate of increase in the concentration of the carbonyl groups within the degraded material is greater than the rate of increase in the concentration of the hydroxyl groups. The infrared spectra for a series of random styrene-acrylonitrile (SAN) copolymers of various compositions were then analyzed to determine the dependence of the individual spectral peaks on the copolymer composition. Correlations were established to relate changes in the peak positions and intensities to changes in the copolymer composition and monomer sequence distribution. A peak was assigned to a given microstructure if there existed a positive linear relationship between the peak intensity and the number fraction of this microstructure. These peak assignments were then applied to the photooxidation studies of SAN to determine the effect of the sequence distribution on the photooxidative process of the copolymer. Peaks at 1952, 1881, 912 and 549 cm-1 were found to have negative intensity values in the difference spectrum of photooxidized SAN. While the peaks at 1881 and 912 cm-1 had been assigned to the SAS triad structure, the peaks at 1952 and 549 cm-1 were assigned to the monad, dyad or triad structures of the styrene repeat unit. It was therefore concluded that the microstructure s (open full item for complete abstract)

Committee: Jack Koenig (Advisor) Subjects:

Doctor of Philosophy, Miami University, 2013, Chemistry and Biochemistry

The goal of the research performed for this thesis was to further develop and evaluate vibrational spectroscopic techniques, specifically infrared and Raman spectroscopies, in challenging sampling situations. Some experiments focused on analyzing samples with techniques that had limited to no previous research while others focused on modifying current techniques providing alternate and possibly improved methods of detection and analysis. Chapter 1 provides background into the fundamentals of infrared and Raman spectroscopy and briefly covers sampling techniques available. Chapter 2 demonstrates that a commercial Raman microscope can be externally modified to sample using attenuated total internal reflectance (ATR). This modification allowed the collection of nanometer thin films without spectral contamination from sub-layers and demonstrated improved collection parameters. Chapter 3 evaluated a constructed dispersive Raman spectrometer operating with near–infrared (NIR) wavelengths to determine polyethylene terephthalate film thickness for process monitoring purposes. Chapter 4 demonstrated the potential capabilities of NIR-diffuse reflectance spectroscopy for the detection of high energy materials to provide alternative methods of detection and increase safety in the battlefield. Chapter 5 was an investigation of a planar array spectrograph employed as a real-time detector for liquid chromatography separations.

Committee: André Sommer Dr. (Advisor); Neil Danielson Dr. (Committee Chair); Shouzhong Zou Dr. (Committee Member); David Oertel Dr. (Committee Member); Paul James Dr. (Committee Member) Subjects: Chemistry