Analytical Chemistry Commons^™

Mechanisms Of Heterogeneous Oxidations At Model Aerosol Interfaces By Ozone And Hydroxyl Radicals, Elizabeth A. Pillar-Little

Theses and Dissertations--Chemistry

Atmospheric aerosols play an important role in climate by scattering and absorbing radiation and by serving as cloud condensation nuclei. An aerosol’s optical or nucleation properties are driven by its chemical composition. Chemical aging of aerosols by atmospheric oxidants, such as ozone, alters the physiochemical properties of aerosol to become more hygroscopic, light absorbing, and viscous during transport. However the mechanism of these transformations is poorly understood. While ozone is a protective and beneficial atmospheric gas in the stratosphere, it is a potent greenhouse gas in the troposphere that traps heat near the Earth’s surface. It also impacts human heath …

Rapid Quantification Of Trypsin Inhibitors In Food And Feed Formulations With Electrospray Ionization Mass Spectrometry, Radheshyam Panta

Doctoral Dissertations

"Presence of anti- nutrients deteriorate the nutritional value of animal foods and feed formulations. The important one being trypsin inhibitors. Trypsin inhibitors in food and feed formulations lower the protein supplement and hence the ultimate consequence is the decrease in growth and development of animals. It is therefore, crucial to monitor trypsin inhibitors in animal food and feed formulations. Research work mentioned in this dissertation is based on the development of rapid, more accurate and robust method for determination of trypsin inhibitor in food and feed formulations. The developed method includes extraction of trypsin inhibitor from food and feed formulation …

Using In Situ Liquid Single Photon Ionization Mass Spectrometry (Spi-Ms) To Probe Lithium Polysulfide Electrolyte In Motion, Aala M. Al Hasan, Jiachao Yu, Juan Yao, Vijayakumar Murugesan, Manjula Nandasiri, Xiao-Ying Yu

STAR Program Research Presentations

The solid-liquid (s-l) interface is the most common interface encountered in electrochemical systems. The s-l interface has wide applications in energy storage, catalysis, and material sciences. In situ studies of chemical reactions taking place on the s-l interfaces can further our understanding of electron transfer and link to real-world device functions under challenging conditions. Direct probing of the solid electrode and liquid electrolyte interface has been realized using a vacuum compatible electrochemical microfluidic reactor, system for analysis at the liquid vacuum interface (SALVI) with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Most recently, the electrochemical version of SALVI was integrated to …

Chemometric And Bioinformatic Analyses Of Cellular Biochemistry, Bradley Worley

Department of Chemistry: Dissertations, Theses, and Student Research

The amount of information collected and analyzed in biochemical and bioanalytical research has exploded over the last few decades, due in large part to the increasing availability of analytical instrumentation that yields information-rich spectra. Datasets from Nuclear Magnetic Resonance (NMR), Mass Spectrometry (MS), infrared (IR) or Raman spectroscopy may easily carry tens to hundreds of thousands of potentially correlated variables observed from only a few samples, making the application of classical statistical methods inappropriate, if not impossible. Drawing useful biochemical conclusions from these unique sources of data requires the use of specialized multivariate data handling techniques.

Unfortunately, proper implementation of …

Noncovalent Interactions Between Alkali Metal Cation And Aza/Thia-Crown Macrocycles: Mass Spectrometric Techniques And Theoretical Studies, Calvin A. Austin

Wayne State University Dissertations

Macrocyclic complexes have been useful in understanding many systems encountered in biology, along with having widespread use in analytical, pharmaceutical, and synthetic chemistry. My goal was to provide a quantitative experimental and theoretical description of cation-aza-crown and thia-crown ether interactions with alkali metal cations. Infrared multiple photon dissociation (IRMPD) action spectroscopy and energy-resolved collision-induced dissociation (CID) techniques were used in conjunction with theoretical electronic structure calculations to characterize the structures, binding interactions, and stability of cation-aza-crown ether interactions. Quantum chemical calculations at several levels of theory were employed to characterize the structures and stabilities of the isolated cations and aza-crown …

Analytical Method Development For The Detection And Analysis Of Protein Carbonyls, Chelsea M. Coffey

Theses and Dissertations

Oxidative stress can result in changes to many biomolecules and also affect their activities. We are interested in protein carbonylation, a type of unnatural oxidation which has been associated with numerous degenerative disease states and is also a consequence of the natural aging process. Protein carbonyls are stable species, but countless analytical barriers exist in terms of their identification. Thus, the main goal of this work was to develop and optimize analytical methods that could be used to help us better understand which, where, and how proteins are being carbonylated.

Initial studies involved method validation for carbonylating, tagging, and enriching …

Determination Of The Structure Of Sphingomyelin By Tandem Mass Spectrometry And Matrix - Assisted Laser Desorption/Ionization, Antonio Ganios

Williams Honors College, Honors Research Projects

Mass spectrometry is a method that uses masses to determine the structure of a compound. This is completed by first charging the compound until it is a cation or anion, and then its molecular weight can be determined by measuring a mass to charge ratio. The focus of this study was determination of sphingomyelin’s structure. The purpose of this was that sphingomyelin has been shown to play a critical role in many biological pathways and being able to identify this lipid could prove to be beneficial for preventative medicine. Utilizing electrospray ionization (ESI) Quadruple-Time-of-flight (Q-TOF) mass spectrometry on a Waters …

Development Of An Extraction Method For The Mass Spectral Analysis Of Organic Gunshot Residue From Clothing, Brent Casper

Theses and Dissertations--Chemistry

This dissertation will focus on the extraction of volatile organic compounds associated with gunshot residue from articles of clothing, followed by analysis with mass spectrometry. During the discharge of a weapon, a cloud of volatile organic gunshot residue (OGSR) is dispersed around a firearm. This will create a high probability of transfer between the OGSR and the clothing of individuals who are near a discharged weapon.

The first part of this dissertation will be the development of a method for removal of volatile OGSR from articles of clothing. Extraction of OGSR will be completed by solid phase microextraction (SPME), followed …

Identification And The Significance Of Selective Proteins In Bile And Plasma Of Normal And Health-Compromised Chickens, Balamurugan Packialakshmi

Graduate Theses and Dissertations

During the last 50 years, animal breeding programs in commercial poultry have made significant progress in the bodyweight gain of broilers but led to several metabolic and skeletal disorders. Lameness associated with proximal femur known as femoral head separation (FHS) or femoral head necrosis (FHN) is one of the major metabolic disorders in poultry industry. In order to select for healthy chickens, markers that can distinguish between healthy and affected birds are required. Biomarkers from blood represent an ideal and rich source of markers which can be obtained using minimally invasive methods. The biomarkers were explored in an experimental model …

Analysis Of Tyrosine And Its Halogenated Forms And Tripeptide –Metal Ion Clusters Using Mass Spectrometry, Bharathi Gannamani

All Capstone Projects

Chapter 1:

The aim of this research project was to measure the differences in proton affinities of tyrosine and its halogenated forms, 3-chlorotyrosine and 3-iodotyrosine. Tandem mass spectrometry was used here to measure the proton affinities. These amino acids were formed as protonated dimers with amino acids of known proton affinity and were introduced into the instrument through electrospray ionization (ESI). Based on the intensities of the protonated amino acids appeared in the mass spectrum when the dimer was isolated and fragmented, the proton affinities of the sample amino acids were calculated.

Chapter 2:

The research project was on mass …

Structural Studies Of Bile Salt Aggregation By Nuclear Magnetic Resonance Spectroscopy And Mass Spectrometry, Nicholas Doyle

Master’s Theses

Bile salts are biomolecules that are produced in the liver and are responsible for a range of functions in the process of digestion, primarily the emulsification of dietary fat and fat-soluble vitamins. Despite their importance in biological chemistry, the structure and dynamics of bile salt aggregation are not well understood. The efforts described herein attempt to enhance the understanding of cholate aggregation numbers (AN), critical micelle concentration (CMC), micellar structure(s), and interactions with a binaphthyl probe molecule. Cholate is the most common bile salt in mammals and is, therefore, a decent model for describing bile salt aggregation. CMC determination is …

Quantitative Mass Spectrometric Investigations Of Protein Biomarkers: Serum Thymidine Kinase 1 And Human Osteopontin, Morse Faria

Theses and Dissertations

Mass spectrometry is being increasingly used in biomarker research mainly due to its ability to achieve high selectivity coupled with high sensitivity. This dissertation focuses on quantitative mass spectrometric investigations of two protein biomarkers i.e. serum thymidine kinase 1 (TK1) and human osteopontin (OPN).

First part of this research was focused on developing a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method for measuring the activity of TK1 in serum by monitoring the conversion of a TK1 specific exogenous substrate, 3’-deoxy-3’-fluorothymidine (FLT), to its mono-phosphorylated form 3’-deoxy-3’-fluorothymidine monophosphate (FLT-MP). A method to quantify FLT-MP on LC-MS/MS was developed and …

Application Of Stir Bar Sorptive Extraction Thermal Desorption Gas Chromatography Mass Spectrometry For The Study Of Water Accommodated Fractions Of Fossil Fuels And Biodiesel, Ricardo Mccreary

Open Access Theses & Dissertations

Even though measures are taken to decrease accidental release of crude oil and refined fuels into the aquatic environment, continued demand of such fuels--particularly in the transportation sector--pose a continued threat to the aquatic environment throughout their handling, processing, and consumption. Even though measures can be taken to remove the visible layers of fuel in water, it has been shown that constituents of these fuels--that partition into water--can have adverse health effects on the aquatic organisms at low concentrations that are not necessarily predictable through the study of the actual fuel's original composition. Consequently, this renders the need for an …

Synthesis And Characterization Of Manganese Pyridazyl Complexes, Sana Shah

Masters Theses & Specialist Projects

Heterocyclic’s and their fused-ring derivatives have been of interest for their use in electronic materials due to their ease of production, synthetic versatility, and low cost compared to traditional inorganic materials like silicon. Pyridazines have been found to be useful in catalysis gas storage, polymeric sensors and biological mimetics. When a transition-metal is fused into a synthesized pyridazine, unique properties such as conductivity and optics are allowed. In this work, synthesized pyridazine complexes will be analyzed by mass spectroscopy, elemental analysis, nuclear magnetic resonance, imaging, x-ray crystallography, and infrared spectroscopy. We are interested in synthesizing organometallic pyridazines and manganese pyridazyl …

Sample Preparation Techniques For The Improvement Of Analytical Measurements: Capillary-Channeled Polymer Fibers Employed In Protein Solid Phase Extraction Applications And Characterization Of Active Components In Botanical Dietary Supplements, Carolyn Burdette

All Dissertations

The task of sample preparation encompasses many challenges and demands for analytical techniques. Appropriate preparative steps can be the determining factor between successful measurements and failures. Too little preparation can lead to the inability to detect analytes due to low concentrations, insufficient extraction of analytes, and/or strong matrix effects; exhaustive preparation steps increases analysis times, the potential for analyte losses, and the difficulty to obtain consistent reproducible results. Discussed here are several examples of analytical techniques where sample preparation is critical and can be used to improve existing techniques. Capillary-channeled polymer (C-CP) fibers used for solid phase extraction (SPE) protein …

Optimization And Validation Of Direct Analysis In Real Time Mass Spectrometry (Dart-Ms) For Quantitation Of Sugars To Advance Biofuel Production, Daudi Sayialel Saang'onyo

Online Theses and Dissertations

A direct analysis in real time mass spectrometry method was developed and validated for the analysis and quantitation of sugars that would be generated from pretreated and hydrolyzed switchgrass. This research aspect can be divided into two sections:

i) Literature Review: A review is presented on the status of energy security and how biomass and biofuels can be utilized as a source of transportation fuel. To this end, biomass (specifically switchgrass) can be broken down by pretreatment methods and then enzymatically hydrolyzed to simple sugars. These sugars can assist with algae growth that can eventually be converted into biofuels. …

Explorations In Homeoviscous Adaptation And Mass Spectral Analysis Of Membrane Lipids, Michael Douglas Timmons

University of Kentucky Doctoral Dissertations

The focus of this dissertation is centered on the mass spectral analysis of lipids and changes occurring in keeping with the concept of homeoviscous adaptation [1]. Homeoviscous adaptation is the process of modification of membrane lipids in response to environmental stimuli [1]. Dissertation investigations applied this concept to prokaryotic and eukaryotic organisms, and expanded the perception of environmental factors from exogenous organic solvents to intracellular environment.

The field of lipidomics deals with the analysis of phospholipid and fatty acid components of membranes the changes that occur due to environmental stimuli and their biological significance [2-6]. The high sensitivity of mass …