Analytical Chemistry Commons^™

The Relation Between Transport Properties And Solvation Structure For Electrolytes., Emanuel Naumann, Lalita Rai, Xingyi Lyu, Huong Nguyen, Tao Li

Honors Capstones

With continued progress in portable technology, energy storage has become an important factor to improve upon as batteries are found in a variety of everyday devices. Lithium-ion batteries are particularly common, although current technology features shortcomings in thermal stability, efficiency, and cost. Such shortcomings are related to current electrolytes in such technologies. The following experiment aims, for noteworthy alternative electrolytes, to analyze both macroscopic measurements related to transport properties and spectroscopy measurements that give insight into samples’ solvation structures. Such data are then used to identify the most promising electrolytes of the ones tested. Solutes tested include the promising imide-based …

Signal And Noise Analysis In An Undergraduate Instrumental Analysis Laboratory, Ken Overway

Chemistry Faculty Scholarship

Understanding the difference between signal and noise in a measurement is fundamental to analytical chemists. The typical instruments found in an undergraduate chemistry department can be used to teach this concept, as well as signal averaging, by giving students hands-on experience with measurements and data processing. This work presents an undergraduate laboratory module (homework and experiment) that provides specific instructions for using gas chromatographs, fluorometers, a nuclear magnetic resonance spectrometer, an atomic absorption spectrophotometer, and an infrared spectrometer to collect replicate measurements and a framework for calculating the noise level, baseline, signal level, signal-to-noise ratio (SNR), and the signal thresholds …

Modified 2-Quinolinones For Photocatalysis: The Fluorescence Quantum Yield (Φf) Of Novel 2-Quinolinone Derivatives, Reggina Moreno Trevino, Graham Griffin

DePaul Discoveries

The photophysical properties of novel 2-quinolinone derivatives were examined to evaluate their potential as photocatalysts using fluorescence and UV-Vis absorbance spectroscopy. The fluorescence quantum yields were determined via the relative comparative method, using target absorbance values at a specific wavelength to prepare solutions and comparing these measurements to the reference molecule carbostyril-124. Molar absorptivity values were also calculated to assess the light absorption properties for each compound. Among the derivatives, PAV-3 presented with the highest molar absorptivity and fluorescence quantum yield values (ε= 15297.3 M-1 cm-1, ΦF= 17.1%), while PAV-5 showed the lowest (ε= 4796.2 M-1 cm-1, ΦF= 2.3%). The …

A Spectroscopic Survey Of Atmospheres Of Super-Earths, Luke Brust

Honors Theses

Recent research has made it possible to use spectroscopy to analyze the composition of the atmospheres of exoplanets, planets that orbit other stars. Most projects thus far have focused on the atmospheres of gas giants, as it is less challenging to observe them with available equipment. This project studies the atmospheres of four Super- Earths, planets that have a mass greater than the Earth but smaller than Neptune. This is accomplished by processing the raw spectroscopic data from the Hubble Space Telescope and modeling the atmosphere using the program 𝝉-Rex3. This survey found clear results from two of the selected …

Turning Trash Into Treasure: Using Old Optical Spectrometers As Learning Tools In Instrumental Analysis, Ken Overway

Chemistry Faculty Scholarship

Chemical instrumentation is complex and expensive. When an instrument becomes nonfunctional, its pedagogical value remains despite its inability to make measurements. This work presents a laboratory experiment which gives new purpose to old optical spectrometers while building knowledge and confidence of students in their understanding of chemical instrumentation. Students are given a guided tour of spectroscopic instruments, starting from the simplest, and are asked to identify components and draw the optical path of each instrument. Allowing students to look inside of decommissioned instruments gives students a chance to see the differences and similarities of optical spectrometers while reinforcing the form …

Inhaling The Unseen: Exploring The Presence Of Microplastics In The Human Respiratory Tract, Kara Coffman-Rea

Graduate Research Theses & Dissertations

Microplastics (plastic pieces less than 5 mm) have emerged as a pervasive form of pollution acknowledged as a universal threat to both environmental and human health. Their small size and widespread distribution pose significant risks to marine life, terrestrial ecosystems, and ultimately human health. Microplastics have been reported in food and drink items designated for human consumption, in cosmetics and consumer goods designed for human use, and within the air we breathe, each providing an entry route for microplastics to enter the human body. Recently, microplastic particles have been detected in a variety of human tissue samples (e.g., lung tissue). …

Spectroscopic Measurements Of Meibum Compositional, Structural, And Functional Relationships To Elucidate The Role Of Meibum In Dry Eye., Anthony Chigozie Ewurum

Electronic Theses and Dissertations

The major aim of my dissertation was to investigate the etiology of dry eye disease which affects about 7 million people in the United States, causing symptoms that can lead to visual disturbance. Correlation between dry eye and an abnormal lipid layer of the tear film has been found. Tear film lipids originate mostly from the meibomian glands. Cholesteryl ester (CE) and Wax ester (WE) lipids make up most of the human meibum lipidome and the CE/WE ratio has been shown to decrease in patients with meibomian gland dysfunction. Model studies using synthetic CE and WE, although providing some insight, …

Spectral Analysis Of A New Electronic Transition Of Platinum Fluoride, Ptf, Carol Welch

Undergraduate Research Symposium

The electronic landscape of platinum containing molecules has been the focus of numerous spectroscopic studies in recent years, because of the difficulty in describing electronic structure theoretically due to electronic correlations and relativistic effects. A collective effort by spectroscopitsts and theoreticians to investigate the diatomic molecule platinum fluoride, PtF, has included research such as developing potential energy diagrams and performing analyses on rotational transitions with microwave spectroscopy. One group observed electronic transitions of PtF using laser vaporization/reaction with jet free expansion and laser induced spectroscopy. A highly effective method for observing and analyzing electronic transitions of small, metal-containing molecules like …

Investigation Of The Interface Reactions Of Ion Selective Electrode Membranes Using Chromatographic And Spectroscopic Analyses Of Erbium(Iii) Tetraphenylporphyrin, Alexis Rae Miller

Graduate Theses/Dissertations

Ion selective electrodes (ISEs) are analytical sensors that monitor the interactions between an ionophore within a polymeric membrane and ions in various solutions. The sensitivity and selectivity of ISEs is directly related to the chemical components. One type of ionopohore utilized in ISEs are metalloporphyrins. Metalloporphyrins have unique binding characteristics, which make them useful in sensors. The polymeric membranes that are synthesized and used in ISEs consist of a metalloporphyrin complex, polyvinyl chloride, and ortho-nitrophenyl octyl ether. The membrane unique to this project contains erbium (III) tetraphenylporphyrin as the metalloporphyrin ionophore. Various analytical techniques were applied in the investigation …

A Project To Dye For : Differentiation Of Dyed And Non-Dyed Human Hairs Using Atr Ft-Ir Spectroscopy, Joseph John Greco

Legacy Theses & Dissertations (2009 - 2024)

IR spectroscopy is widely utilized for forensic purposes due to the chemical fingerprint the method provides. ATR FT-IR spectroscopy is particularly advantageous because it allows for spectra to be collected quickly, accurately, and perhaps most importantly for forensics, non-destructively. Human hair is commonly collected at a crime scene, and further analyzed using DNA analysis and microscopy. However, these techniques have limitations. In the past ATR FT-IR spectroscopy has shown promise in the analysis of human hair for forensic purposes. In this study, the differentiation of undyed hair versus dyed hair classes of varying colors based on their IR spectra were …

Experimental And Theoretical Investigation Of Regioselectivity For A Series Of Ketoimines With Nuclear Magnetic Resonance Spectroscopy And Density Functional Theory, Amanda Stahl, Joseph M. Fritsch, Kelsey R. Brereton

Seaver College Research And Scholarly Achievement Symposium

A series of ketoimines bearing pendant quinolyl substituents were prepared by Schiff base condensation of 1,3-diketones with two different substituents: trifluoromethyl and an alkyl/aryl group (e.g., Me, Et, ⁱPr,^tBu, Ph. Synthetic reactions of ketoimines with varying alkyl/aryl substituents altered the distribution of regioisomers as measured in isolated yields and detected by ¹H and ¹⁹F NMR spectroscopy of crude reaction mixtures. Reaction with the least sterically encumbered diketone (CF₃with Me) resulted in mixture of ketoimines with virtually quantitative formation of the ketoimine resulting from quinolyl addition to the carbonyl adjacent to the alkyl substituent. …

Extensible Interface For A Compact Spectrophotometer For Teaching Molecular Absorption In The Undergraduate Laboratory, Edward Navarre

SIUE Faculty Research, Scholarship, and Creative Activity

A simple computer interface for controlling a compact spectrograph for use as a spectrophotometer in an undergraduate teaching laboratory was developed. The project was implemented on a Raspberry Pi computer which permits the integration of a light source into the software. The interface was written in Python to facilitate modification by the user and because of its compatibility with several computing platforms. An implementation of the project in Linux on a Raspberry Pi computer is described.

Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton

Online Theses and Dissertations

Eastern Kentucky is home to many private ponds used for agricultural and recreational purposes. Each year, the owners of these ponds observe harmful algal blooms (HABs) that release toxins into the water, potentially limiting the use of these ponds. A pilot study in summer 2018 observed a harmful algal bloom (HAB) occurring in one pond in Madison Country that roughly correlated with a rise in water sulfate levels with no detectable levels of nitrate or phosphate present. A follow-up study of this pond and others in the area was conducted during Summer 2019. The purpose of this project was three-fold: …

The Forensic Analysis Of Adult Temporary Tattoos, Paige Cooper

Student Theses

Adult temporary tattoos have become more popular, yet there is very little research on them, especially regarding their use in forensics. This poses a problem because forensic investigators may not be able to distinguish a temporary tattoo from a real tattoo, possibly hindering their investigation. In this study, various types of adult temporary tattoos were examined and analyzed in attempts to identify and distinguish them, both from each other and from permanent tattoos. Infrared spectroscopy, specifically attenuated total reflection (ATR), proved to be more useful than ultra-violet visible light spectroscopy in terms of analyzing the samples. The natural adult temporary …

Elemental Analysis Of Edible Clay From The Copperbelt Province Of Zambia, Amelia M. Craze, Mina L. Brandon

Venture: The University of Mississippi Undergraduate Research Journal

Trace elements in three edible clay samples from an open-air market in Kitwe, Zambia were analyzed for heavy metals using a scanning electron microscope coupled with an energy-dispersive spectrometer. The ingestion of clays has been observed throughout history but persists in many rural countries that lack sufficient access to proper medical care. In many African countries, women have been observed eating clay during pregnancy to reduce nausea or meet their recommended intake of iron. Similar studies identified harmful heavy metals in the makeup of the edible clays, however, the results of this analysis elemental analysis coupled with the SEM for …

Chemical Kinetics Using A Smartphone Spectrometer, Mary Greggila

Williams Honors College, Honors Research Projects

In a time where many high school science classes are lacking in quality laboratory education, there is a need for accessible chemical equipment that enhance teaching fundamental concepts of chemistry with ease and at a low cost. The DualSpec handheld smartphone spectrometer aims to be a quality open-source spectroscopic instrument that can easily be made and used at home by people of any scientific level. This research sought to show that the DualSpec could be used to teach higher level spectroscopic concepts such as those used in chemical kinetics. The DualSpec was compared to a commercial spectrometer using the commonly …

Designing A Calibration Set In Spectral Space For Efficient Development Of An Nir Method For Tablet Analysis, Md Anik Alam

Electronic Theses and Dissertations

Designing a calibration set is the first step in developing a spectroscopic calibration method for quantitative analysis of pharmaceutical tablets. This step is critical because successful model development depends on the suitability of the calibration data. For spectroscopic-based methods, traditional concentration based techniques for designing calibration sets are prone to have redundant information while simultaneously lacking necessary information for a successful calibration model. The traditional method also follows the same design approach for different spectroscopic techniques and different formulations, thereby lacks the optimizing capability to be technique and formulation specific.

A method for designing a calibration set in the Near …

Foutier Transform Infrared Spectroscopy Instrumentation And Integration With Thermogravimetry, Junjie Xiang

Masters Theses & Specialist Projects

To discover the potential of IR spectroscopy and explore the details of FTIR instrumentation, a FTIR was built from most basic parts to provide access to every aspect of a IR spectrometer including the hardware and software. The optical system followed the most widely used double-interferometer design. The software control system was developed with LabVIEW to perform data acquisition of the detectors, data processing and controls of the actuators. The FTIR built will be able to provide a full optical IR spectroscopy platform which has a complete control and data acquisition system and can be continuously improved in accuracy and …

Further Development Of Raman Spectroscopy For Body Fluid Investigation : Forensic Identification, Limit Of Detection, And Donor Characterization, Claire K. Muro

Legacy Theses & Dissertations (2009 - 2024)

The challenges to forensic body fluid analysis have placed limitations on the type of information that investigators can acquire and how that information can be collected. In recent years, Raman spectroscopy has proven itself useful for characterizing body fluids. In 2008, a large-scale investigation was undertaken to explore the use of Raman spectroscopy as a means of identifying body fluids. This work resulted in multidimensional Raman spectroscopic signatures for the five main body fluids: semen, peripheral blood, saliva, vaginal fluid, and sweat. These studies were incredibly successful and created the foundation for years of continued research. Accordingly, the studies included …

Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera

Honors Undergraduate Theses

In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 μm in the lateral and 3.6 μm in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single …

Quantitative Analysis Of Acetylsalicylic Acid By Q-Nmr (Quantitative-Nuclear Magnetic Resonance Spectroscopy), Charles Flemming Jr.

All Student Theses and Dissertations

Quantitative analysis is an important step during pharmaceutical drug development. Currently, the pharmaceutical industry uses high performance liquid chromatography (HPLC) for quantitative analysis of organic compounds as the preferred technique. The proton nuclear magnetic resonance (NMR) technique has an inherent ability to quantify a given analyte and may be used to quantify organic compounds. Quantitative nuclear magnetic resonance spectroscopy (q-NMR) of acetylsalicylic acid (ASA) was conducted using tert-butyl alcohol (tert-butanol) as the internal standard and deuterated chloroform (CDCl₃) as the solvent. Preparations of ASA solutions in low and high concentration ranges, 1.0 mM – 10.1 …

Ultraviolet And Infrared Spectroscopy Of Synthetic Foldamers, Aib Homopeptides, And Solvated 1,2-Diphenylethane In The Gas Phase, Joseph R. Gord

Open Access Dissertations

The work presented here implements a supersonic jet expansion source to funnel the population of model peptides and solvated-bichromophore clusters into their low lying structural minima and to collisionally cool these minima to their respective zero-point vibrational levels. Single-conformation ultraviolet and infrared spectroscopy techniques are then used to probe these systems and investigate their electronic properties and uncover their intrinsic conformational preferences in the gas phase.

Model β/γ-peptides known as synthetic foldamers and aminoisobutyric acid (Aib) homopeptides incorporate structural constraints that are designed/known to impose particular structural motifs. Here the ability of a β/γ-dipeptide to replicate the backbone length of …

3d Printing Applications Within Spectrophotometry, Eric J. Stanczyk

Williams Honors College, Honors Research Projects

Ultraviolet-visible spectroscopy is a tool used throughout the field of chemistry and in chemical labs across the world. Spectrophotometers are a core technology in analytical chemistry, and are used to obtain accurate data on solution concentration. Unfortunately spectrophotometers can be difficult to obtain due to their high cost and low availability outside of a laboratory; this is especially true in either high school or lower grades where buying a spectrophotometer could be considered unreasonable due to price. There are ways to obtain cheaper spectrophotometers, but they can have a high initial cost or low overall quality. This paper will discuss …

Study And Identification Of Environmental Nanoparticles In Governors State University (Gsu's) Agricultural Fields, Ekta Desai

All Capstone Projects

Main purpose of this project is to study nanoparticles in Governors State University’s agricultural field and design experimental protocol for the same. Nanoparticles have one dimension that measures between 1 - 100 nanometers or less. Nanoparticles are widely used in day to day life such as in medicines, textiles, manufacturing and cosmetics. Due to their wide use, they can enter environment through many ways such as accidental spills during handling. Waste water treatment plant disposal serves as a main source of their entrance into the environment. Analysis of nanoparticles in environmental samples presents a number of challenges, including separation and …

Vibrational Spectroscopic Analysis Of Gunshot Residue : A Novel Approach For Detection And Characterization, Justin J. Bueno

Legacy Theses & Dissertations (2009 - 2024)

Due to the increasing prevalence of firearm related crimes, there is a need for an all-encompassing analytical technique which can rapidly detect and analyze trace crime scene firearm evidence. There are several forms of ballistics and trace evidence associated with firearm offenses. Historically, the most neglected piece of evidence has ironically been the most prevalent. Each firearm discharge produces a so called gunshot residue (GSR) sample, expelling dust and particles numbering from hundreds to thousands throughout the shooting environment. The detection of GSR at a crime scene or on a suspect is critical for determining what actually happened during a …

Raman Spectroscopic Analysis Of Body Fluids : Species Differentiation And The Effect Of Substrate Interference And Laser Power, Gregory Keith Mclaughlin

Legacy Theses & Dissertations (2009 - 2024)

Several recent discoveries demonstrate that Raman spectroscopy has a unique capability to characterize body fluid traces in a forensic capacity. This approach has thus garnered interest in the forensic community since 2008, when a proof of concept experiment established that blood, semen, vaginal fluid, sweat and saliva are easily differentiable through their Raman spectra. Several possible methods of identification have been described in the literature, one approach uses chemometrical models, and another applies recently formulated multidimensional Raman signatures. The analytical sampling method and the identification procedure provide several desirable traits for the field of forensic science. In particular, Raman spectroscopy …

Non Aggregated Colloidal Silver Nanoparticles For Surface Enhanced Resonance Raman Spectroscopy, Aoife Power, John Cassidy, Tony Betts

Articles

Silver nanoparticles with a tuneable l max were produced as colloids by heterogeneous nucleation. The synthesis process is both fast and repeatable, producing stable PVA capped nanoparticles. The colloid’s effectiveness in the SERRS system was investigated using Rhodamine 6G, R6G, Crystal Violet, CV, and Malachite Green, MG, as probe molecules. A clear sensing trend was observed, where the Raman signal emitted was significantly enhanced by the addition of silver nanoparticles. A build up of signal intensity is observed until an optimum ratio is achieved, followed by a decline in signal intensity as the concentration of nanoparticles is further increased. The …

Elucidating The Structure Of Protein Aggregates By Raman Spectroscopy, Ludmila A. Popova

Legacy Theses & Dissertations (2009 - 2024)

The structures and properties of amyloid fibrils are of considerable interest due to their associations with numerous neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and transmissible spongiform encephalopaties (prion diseases). Understanding fibrillogenesis at a molecular level requires detailed structural characterization of amyloid fibrils. However amyloid fibrils are difficult objects to study due to their non-crystalline and insoluble nature. These properties make the application of classical tools of structural biology, such as X-Ray crystallography and solution Nuclear Magnetic Resonance spectroscopy, impractical for structural characterization of protein fibrils.