Analytical Chemistry Commons^™

Laser Ablation-Atomic Absorption Spectroscopy Of Yttrium Plasma, Dawn Gipson

Create@State

Laser ablation is a widely used sampling method for elemental chemical analysis. Laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively-coupled mass spectrometry (LA-ICP-MS) are the two most common implementations. Application of these techniques is found throughout the sciences, including analysis in archaeological settings, geology, and medical analysis of hard tissue such as teeth or bone. Many applications benefit from the microdestructive nature of the technique. However, the relationship between the laser-ablation crater and the analytical signal is poorly understood. Laser ablation-atomic absorption spectroscopy (LA-AAS) is used in our laboratory to determine the mass of material incorporated into the plasmas in …

Designing Surface-Induced Entatic States In Copper Complexes For Tunable Reactivity, Rachel Kiser

Senior Theses

Copper catalysts play an important role in electrocatalytic oxidation reactions due to their redox flexibility and relative abundance compared to noble metal catalysts. In biological systems, copper metalloenzymes often achieve enhanced reactivity through an entatic state. Entasis is described as an active site or metal center being constrained to a geometric and electronic state, minimizing primary sphere reorganization energy and achieving higher rates of electron transfer.  This study investigates whether entasis can be achieved in synthetic molecular catalysts by immobilizing Cu(I) complexes onto metal oxide surfaces. Two Cu(I) complexes bearing carboxylate-functionalized ligands were examined both in homogeneous solution and when …

Radicals Transforming Organic Matter: Implications For Non-Pyrogenic Black Carbon And Nitrogen Formation, Molecular Dynamics In Tropical Soils, And Lignin Valorization, João Vitor Dos Santos

Chemistry & Biochemistry Theses & Dissertations

Radicals drive the transformation of organic matter in natural and engineered systems, altering its structure, reactivity, and stability. Condensed aromatic carbon (ConAC) and condensed aromatic nitrogen (ConAN) are among the most persistent forms of organic matter in soils and are traditionally interpreted as products of biomass burning. This dissertation challenges the long-standing assumption that these materials are exclusively pyrogenic, showing that iron-mediated radical chemistry can generate condensed aromatic structures under ambient conditions.

Chapters II and III show that Fenton-like radical oxidation of lignin-rich biomass produces condensed aromatic structures compositionally similar to pyrogenic black carbon and black nitrogen when assessed with …

Anthrone-Based Dummy Molecularly Imprinted Polymer For The Selective Detection Of Fluorene And Phenanthrene In Simulated River Water, Aria Pinandita, Nurrahmi Handayani, Muhammad Iqbal, Untung Triadhi, Rusnadi Rusnadi, Samitha Dewi Djajanti, Muhammad Bachri Amran, Muhammad Ali Zulfikar

Makara Journal of Science

A dummy-template molecularly imprinted polymer (DMIP) was synthesized via precipitation polymerization using anthrone as a template analog for the selective analysis of low-molecular-weight polycyclic aromatic hydrocarbons (PAHs), specifically fluorene and phenanthrene. Styrene, benzoyl peroxide, and ethylene glycol dimethacrylate were employed as the functional monomer, radical initiator, and crosslinking agent, respectively. The synthesized polymers were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and particle size analysis. The imprinting factors were 1.16 and 1.09 for fluorene and phenanthrene, respectively, indicating enhanced affinity of the imprinted sites. High-performance liquid chromatography analysis following DMIP-based solid-phase extraction yielded recoveries of 91.49% ± 3.87% for …

A Ferrocene-Modified Carbon Electrode Prepared From Coconut Shell Char For Cu(Ii) Detection In Water, Nabila Putri Aulia, Fitria Rahmawati, Abu Masykur, Eddy Heraldy

Makara Journal of Science

A ferrocene (Fc)-modified carbon electrode was prepared from coconut shell char (CSC), which was activated with NaOH to produce an activated coconut shell carbon (Ac-CSC). The carbon electrode was designed as a printed-carbon electrode consisting of working, counter and reference electrodes in a single piece, called a screen-printed carbon electrode, or SPCE. An Fc solution was applied to the working electrode part at 10%, 20% and 30% mass of the SPCE, producing an SPCE-Fc as an electrochemical sensor for Copper ions Cu(II) detection. The prepared activated carbon was analysed by XRD, FTIR, SEM/EDX, surface area analysis and impedance measurement to …

Interview With Orca Award Winner David Hage, Unl Chemistry; Drug-Protein Interactions, Mark Griep, David Hage

UNL ORCA Interview Series

Prof. David Hage was awarded the ORCA in 2018. He was born in La Crosse, Wisconsin, and earned a bachelor’s in chemistry at the University of Wisconsin in La Crosse. Next, he earned a doctorate from Iowa State University and did postdoctoral work at the Mayo Clinic in Rochester, Minnesota. In 1989, he joined UNL as an assistant professor of chemistry and quickly rose through the ranks. He has won many awards and, for the past 13 years, has been the James Hewet University Professor of Chemistry. Allow me to share some remarkable facts about Dave before we get into …

Determination Of Trace Amounts Of Pb2+ And Cu2+ Ions In The Ohio River With Anodic Stripping Voltammetry And Flame Atomic Absorption Spectroscopy To Test Water Contamination From Factories., Eliana Purcell

The Cardinal Edge

In this project, water near factories in Rubbertown, Louisville, KY were tested to see if a significant enough amount of waste is deposited in the Ohio River that the concentrations of Pb2+ and Cu2+ exceed the maximum contaminant levels the World Health Organization (WHO) and the United States Environmental Protection Agency (EPA) have set in place. Waste from industrial factories may contain contaminants that have negative effects on aquatic ecosystems and even human health, so two potentially harmful metal ions were tested. The concentration of Cu2+ in water samples was detected through flame atomic absorption spectroscopy (FAAS), and the concentration …

Peruvian Pinniped Teeth Trace Element Data-Tracking Ecosystem Variabilites Through Trace Element Record Found In Peruvian Pinniped Dentin, Dimitrios Giarikos, Amy Hirons, Ally E. Sheehan, Radleigh Santos

SECLER Data

The South American sea lion (Otaria byronia; SASL) and the Peruvian fur seal (Arctocephalus australis; PFS) are apex predators within the Humboldt Current ecosystem, where population dynamics respond to both natural variability and anthropogenic pressures, including El Niño–Southern Oscillation (ENSO) events and coastal mining. This study quantified 18 trace elements (TEs) in canine dentin from both species collected at Punta San Juan, Peru using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to evaluate long-term environmental exposure. Because dentin is deposited incrementally, it preserves a chronological chemical archive reflecting ontogenetic shifts in diet and habitat use. Overall, TE concentrations were broadly similar …

Physical And Chemical Study Of Interaction In The Urea–Valine System For The Creation Of Modified Liquid Nitrogen Fertilizers, Suvonkul Erkhanovich Nurmonov, Saydullo Khamidovich Azimov

Chemical Technology, Control and Management

This study reports the results of a comprehensive physicochemical investigation of the urea–L-valine binary system, conducted to validate its potential as a modified base for liquid nitrogen fertilizers.

By utilizing the methods of isomolar series, visual-polythermal analysis, X-ray phase (XRD) and single-crystal X-ray diffraction (SC-XRD), synchronous thermal analysis (TGA/DTA), and FT-IR spectroscopy, it was determined that the interaction between components in both aqueous solutions and the solid phase results in the formation of molecular associates stabilized by hydrogen bonds, without the formation of new stoichiometric compounds.

The concentration and temperature limits of the system's stability were defined, revealing a reduction …

Comparison Of Analytical Techniques From The Extraction Of Bioactive Compounds From Kratom, Curry, Ginger, And Turmeric, Riley Bruno

Honors Program: Senior Projects (Public)

Plants, herbs, and spices have been used as medicines for thousands of years. Early civilizations often attributed healing properties of plants to magical or divine forces. However, as chemistry and analytical technology advanced between the 16th and 18th centuries, scientists began to understand that bioactive compounds within the plants actually caused these effects. Today, natural products remain extremely important in drug discovery. As the number of newly developed synthetic drugs declines, there has been renewed interest in identifying biologically active molecules from plants. Bioactive molecules are a group of diverse chemical compounds that stimulate a response in living tissues. The …

An Electrochemiluminescence-Based Arsenic (Iii) Sensor Using Luminol On Screen-Printed Gold Electrodes, Harmesa Harmesa, Isnaini Rahmawati, Andrea Fiorani, Yasuaki Einaga, Eny Kusrini, A’An Johan Wahyudi, Asep Saefumillah, Tribidasari A Ivandini

Journal of Electrochemistry

Electrochemiluminescence (ECL) of luminol has been studied on a screen-printed gold electrode for a simple and sensitive detection of arsenic ions (As(III)). Cyclic voltammetry (CV) was applied as the proposed technique to study luminol’s electrochemical behavior and to evaluate the arsenic’s effect in the ECL system, while hydrogen peroxide (H₂O₂) served as a co-reactant to enhance luminol’s light emission under alkaline conditions. To achieve optimal electrode performance, key parameters including pH, scan rate, and the concentrations of H₂O₂ and luminol were carefully optimized. The presence of As(III) induced a quenching effect on the …

An Undergraduate Chemistry Experiment Integrating Theoretical And Practical Aspects Of Hypervalent Iodine(I) Compounds, Vladimir L. Kolesnichenko, Galina Z. Goloverda

Faculty and Staff Publications

A simple reaction sequence has been developed to produce iodine chloride-pyridine (PyICl) and pyridinium dichloroiodate (PyHICl2), convenient iodinating agents, in a high yield. Our approach is safe and simple to handle, avoiding the use of elemental chlorine or hazardous manipulations. Designed for an upper-level undergraduate hybrid lecture/lab chemistry course, the experiment integrates key concepts from both inorganic and organic chemistry. The pre-experiment lecture explains the connections between molecular structure, reactivity trends, and reaction types. Over three 4 h lab sessions, students carry out a sequence of quantitative transformations and characterize each intermediate and the final product using ESI mass spectrometry, …

Lc-Ms/Ms Method Development For The Analysis Of Cannabinoids In Wastewater, Abigail M. Castellanos, Ava La Lande

The Kean Review: Journal in Student Research

The goal of this research was to establish a reliable method to detect the presence of cannabinoids in wastewater and increase the sensitivity of detection. Since the legalization of cannabis in many states, toxicology research has expanded on methods of detection in hopes of identifying usage patterns. At the Joint Meeting of Essex and Union Counties, it was established that cannabinoids are not thoroughly accounted for in the process of filtering wastewater in addition to our limited understanding of consumption trends. This stands true for many wastewater facilities, especially as the intake of cannabis remains prevalent for various populations across …

Monosaccharide Binding To Synthetic Carbohydrate Receptor Microarrays, Milan A. Shlain

Dissertations, Theses, and Capstone Projects

Chapter 1: A glycan detection platform comprised of synthetic carbohydrate receptors (SCRs) immobilized onto polymer brushes was prepared. SCR043, an alkene-containing SCR, was incorporated into grafted-from polymer brushes using hypersurface photolithography, resulting in microarrays of SCR043-functionalized polymer brushes, where brush height (h) and SCR grafting density (Γ) is controlled precisely at each feature in the array. The influence of h and Γ on the binding to five fluorescently labelled monosaccharides – α-glucose (α-Gluc-FL), α-galactose (α-Gal-FL), α-mannose (α-Man-FL), β-glucose (β-Gluc-FL), and β-galactose (β-Gal-FL) – in aqueous buffer …

The Behavior And Complexation Of Technetium Under Conditions Relevant For Nuclear Fuel Reprocessing, Rachel E. Greenberg

Dissertations, Theses, and Capstone Projects

Spent nuclear fuel is reprocessed by utilizing several large-scale solvent extraction processes. One of the most prevalent of these processes is the plutonium uranium reduction extraction (PUREX) process. This process involves an organic phase composed of tributyl phosphate (TBP) in kerosene and an aqueous phase comprised of concentrated nitric acid. Both uranium (U) and plutonium (Pu) are extracted into the organic phase by nitrate and TBP complexation while the various fission products remain in the initial aqueous phase. Pu is then chemically reduced to its trivalent state and back-extracted into a second aqueous phase, thereby separating the two fissile materials. …

Design Of Lithium-Based Battery Electrolyte Compositions For Extreme Operating Conditions Using Alternative Solvents, Co-Solvents And Additives, Michael J. Keating

Dissertations, Theses, and Capstone Projects

Lithium-ion battery utilization is widespread due to relatively high capacity and long cycle life. Advanced technologies have specific demands of their energy storage devices that traditional Li-ion batteries are unable to meet. Lithium-ion batteries utilize a graphite anode which has a limited theoretical capacity. Traditional lithium-ion batteries also utilize flammable solvents in their electrolyte mixtures. Due to the flammable electrolyte, lithium-ion batteries are not considered practical for large scale applications. Additionally, the lithium-ion battery has a narrow optimal operating temperature window. The temperature limitation of lithium-ion batteries leads to issues for many applications such as operating in extreme temperature environments, …

Iron-Involved Orr Electrocatalysts Under The Lens Of In-Situ/Operando Mössbauer Spectroscopy, Sumbal Farid, Jun-Hu Wang

Journal of Electrochemistry

Exploring cost-effective and efficient catalysts for oxygen reduction reaction (ORR) poses a significant challenge, especially in the pursuit of alternatives to precious metals like platinum. Significant advancements have driven electrochemists to develop efficient ORR catalysts using abundant materials, particularly iron (Fe)-based, known for their exceptional performance in ORR. While the crucial function of Fe in boosting ORR catalytic activity is recognized, the connection between material attributes and catalytic performance remains enigmatic. Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts. Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of …

Development And Validation Of An Analytical Method For Quantitative Determination Of Small Aldehydes In Plasma, Stephanie T. Clark

Chemistry & Biochemistry Theses - Archive

Small aldehydes such as formaldehyde and acetaldehyde are highly reactive metabolites that play important roles in biological processes related to oxidative stress, metabolism, and DNA damage. Because of their chemical reactivity, volatility, and low endogenous concentrations, accurate measurement of these compounds in biological samples remains analytically challenging. The goal was to develop and evaluate a practical analytical method for detecting small aldehydes in biologically relevant matrices using headspace gas chromatography mass spectrometry (HS-GC-MS). The method combined chemical derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) and headspace sampling to stabilize aldehydes and enable selective detection by mass spectrometry. Method development focused on optimizing derivatization …

Advancing Lipidomics Through Fluoroalcohol-Induced Multiphase Fractionation And Orthogonal Lc×Lc–Ms Detection, Md Al Amin

Chemistry & Biochemistry Dissertations

Comprehensive characterization of the lipidome remains a significant analytical challenge due to the immense structural diversity, wide dynamic range, and complex physicochemical continuum of lipid species. Conventional extraction methods, such as those by Bligh–Dyer and Folch, and one-dimensional liquid chromatography (1D-LC) often fail to resolve this complexity, leading to chromatographic overlap, severe ion suppression, and limited coverage of low-abundance or highly hydrophobic species. This dissertation addresses these bottlenecks by establishing a separation-driven analytical framework that integrates novel fluoroalcohol-induced multiphase systems (FAiTPS) with orthogonal multidimensional liquid chromatography–mass spectrometry (LC×LC–MS).

The core of this research is the development and physicochemical characterization of …

Flow Injection Determination Of Fluoride For Total Organic Fluorine Analysis, Memona Zulafiqar

Chemistry & Biochemistry Theses

Poly- and perfluoroalkyl substances (PFAS) are anthropogenic chemicals that have gained increasing attention due to their association with a wide range of adverse health effects. These compounds are highly diverse, with approximately 15,000 PFAS reported. Their exceptional environmental stability and strong tendency to bioaccumulate result in environmentally relevant concentrations that typically occur at very low levels, often in the ng L⁻¹ range. This chemical diversity presents a major analytical challenge, as reference standards are available for only a limited number of PFAS. Consequently, conventional targeted analytical methods frequently quantify less than 1% of the total PFAS present, leading to a …