Analytical Chemistry Commons^™

Variations In Concentrations And Compositions Of Polycyclic Aromatic Hydrocarbons (Pahs) In Coals Related To The Coal Rank And Origin, Susanne Laumann, Vesna Micic Batka, Michael A. Kruge, Christine Achten, Reinhard Sachsenhofer, Jan Schwarzbauer, Thilo Hofmann

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The release of unburnt coal particles and associated polycyclic aromatic hydrocarbons (PAHs) may cause adverse impacts on the environment. This study assessed variations in the concentration and composition of PAHs in a set of fifty coal samples from eleven coal basins worldwide. The maximum PAH concentrations at high volatile bituminous rank were recorded in samples from a single basin. Considering the entire sample, the highest PAH concentrations were in fact found outside of this rank range, suggesting that the maceral composition and thus the coal's origin also influenced PAH concentrations. The examination of the PAH compositions revealed that alkylated 2-3 …

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. …

High Resolution Hybrid Mass Spectrometry For The Determination Of Marine Biotoxins, Azaspiracids, And Their Biotransformation Products., Zuzana Skrabakova

Theses

Azaspiracids (AZAs), polyether marine toxins, are produced by marine microalgae and accumulate in filter-feeding bivalve molluscs, such as mussels, clams, oysters and scallops, while grazing on phytoplankton, from which they derive nutrition. Although being discovered quite recently, AZAs have caused several human intoxication events and thus became a problem for health authorities and shellfish industries. The rapid development of highly sensitive liquid chromatography multiple tandem mass spectrometry (LC-MS/MS, LC-MS") methods enabled the identification of numerous AZA analogues and added to the control of shellfish contamination. Tandem mass spectrometry techniques, while being highly selective and sensitive for determination of AZAs in …

Analysis Of Gaba And Glutamate In The Mouse Dorsal Striatum, Stella Wisidagamage

Wayne State University Theses

ABSTRACT

ANALYSIS OF GABA AND GLUTAMATE IN MICE BRAIN

by

STELLA WISIDAGAMA

May 2011

Advisor: Dr. Tiffany Mathews

Major: Chemistry (Analytical)

Degree: Master of Science

GABA and glutamate are the predominant inhibitory and excitatory amino acid neurotransmitters in the central nervous system (CNS), respectively. However, their altered levels cause several neurological diseases including Parkinson's and Huntington's disease, schizophrenia, and epilepsy. It is important to measure their levels in the extra- and intracellular environments to better understand and develop improved therapeutics that will treat these neurological disorders. The principle aim of this study is to study the impacts of different endogenous …

Quality Characteristics Of Virgin Coconut Oil:Comparisons With Refined Coconut Oil, Fabian M. Dayrit, Ian Ken D. Dimzon, Melodina F. Valde, Jaclyn Elizabeth R. Santos, Mark Joseph Garrovillas, Blanca J. Villarino

Chemistry Faculty Publications

Virgin coconut oil (VCO) is a vegetable oil that is extracted from fresh coconut meat and is processed using only physical and other natural means. VCO was compared to refined, bleached, and deodorized coconut oil (RCO) using standard quality parameters, 31 P nuclear magnetic resonance (NMR) spectroscopy, and headspace solid-phase micro - extraction/gas chromatography mass spectrometry (SPME/GCMS). VCO tends to have higher free fatty acids (FFAs), moisture, and volatile matter and lower peroxide value than RCO. However, the range of values overlap and no single standard parameter alone can be 31 used to differentiate VCO from RCO. Using 31P NMR, …

Single Cell Analysis For The Characterization Of Cell Populations Using A Live Cell Array, Maureen Ann Walling

Legacy Theses & Dissertations (2009 - 2024)

In the past decade, the shift from whole cell population analyses towards single cell measurement methods and techniques is based on experimental results that reveal significant levels of non-genetic heterogeneity in clonal cell populations. This heterogeneity manifests in multiple aspects of cell activity and is, in part, a result of stochastic noise in processes leading to gene expression, namely transcription and translation. The growing understanding of this occurrence has led to the development of methods to monitor and analyze heterogeneity for a more thorough description of cell populations and overall activity.

Advanced Statistical Methods For Biochemical And Forensic Applications Of Raman Spectroscopy, Vitali Sikirzhytski

Legacy Theses & Dissertations (2009 - 2024)

This work is dedicated to the development and application of advanced statistical methods for biochemical and forensic applications of Raman spectroscopy. We developed a new concept of multidimensional Raman signatures for forensic identification of body fluid traces, which was successfully applied to the study of dried blood, semen, saliva, sweat and vaginal fluid stains. Several alternative advanced chemometric techniques were also successfully tested for the problems of pure body fluids discrimination and mixture analysis. Studies of body fluid mixtures with low blood and semen concentrations indicated that the detection limit of a minor contributor was as low as a few …

Accumulation, Speciation, And Distribution Of Metal(Loids) In Plants: Applications Of Synchrotron Techniques In Environmental Sciences, Hiram Castillo-Michel

Open Access Theses & Dissertations

In the last two decades, synchrotron based techniques have gained popularity and been increasingly used in environmental sciences. The present dissertation has relied significantly in the use of synchrotron based techniques to study the speciation, coordination, and distribution of toxic metal(loids) in plants. This study included three plant species: Parkinsonia florida, Prosopis juliflora, and Zea mays. P. florida is a plant species native to the semi-desert regions of North America. The cultivation characteristics of this shrub/tree suggest that it could be used for phytoremediation purposes in semiarid regions. P. florida plants were tested for their capacity to remove arsenic (As) …

Quality Of Wastewater In The El Paso, Texas Region--Analysis Of Pharmaceuticals And Personal Care Products Using High Performance Liquid Chromatography Tandem Mass Spectrometry, Rodolfo Guerrero Jr.

Open Access Theses & Dissertations

Pharmaceuticals and Personal Care Products (PPCPs), such as household cleaning materials, prescription medication, and personal hygiene products, are pollutants of emerging concern that are found in 80% of our water system. Because of their applications, PPCPs are subsequently being released into wastewater; however, current wastewater treatment facilities are not regulated or designed to remove PPCPs. Therefore, these compounds are discharged into the environment on a continual basis. The effects of PPCPs on human health are not yet well known; however, recent research has found that exposure to these chemicals has some adverse developmental effects on aquatic species at low concentrations …

Elastic Properties Of Poly(Vinyldene Fluoride) (Pvdf) Crystals: A Density Functional Theory Study, Yong Pei, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We computed structural and elastic properties of totally nine phases of poly(vinyldene fluoride) (PVDF) crystals using the density-functional theory (DFT) method with and without inclusion of the dispersion corrections. In addition to the four known crystalline forms, mechanic properties of five theoretically predicted crystalline forms of PVDF are also investigated. The all-trans form I_p exhibits the largest cohesive energy, bulk, and Young’s modulus among the nine crystalline forms. The DFT calculations suggest that the δ crystalline forms (III_au, III_pu, III_pd, and III_ad) possess poor chain rigidity among the nine PVDF …

Structure Evolution Of Gold Cluster Anions Between The Planar And Cage Structures By Isoelectronic Substitution: AuN− (N = 13–15) And MauN− (N = 12–14; M = Ag, Cu), Rhitankar Pal, Lei-Ming Wang, Wei Huang, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The structural and electronic effects of isoelectronic substitution by Ag and Cu atoms on gold cluster anions in the size range between 13 and 15 atoms are studied using a combination of photoelectron spectroscopy and first-principles density functional calculations. The most stable structures of the doped clusters are compared with those of the undoped Au clusters in the same size range. The joint experimental and theoretical study reveals a new C_3v symmetric isomer for Au₁₃ ⁻, which is present in the experiment, but has hitherto not been recognized. The global minima of Au₁₄ ⁻ and Au …

Human Fatty Acid Transport Protein 2a/Very Long Chain Acyl-Coa Synthetase 1 (Fatp2a/Acsvl1) Has A Preference In Mediating The Channeling Of Exogenous N-3 Fatty Acids Into Phosphatidylinositol, Elaina M. Melton, Ronald Cerny, Paul A. Watkins, Concetta C. Dirusso, Paul N. Black

Ronald Cerny Publications

The trafficking of fatty acids across the membrane and into downstream metabolic pathways requires their activation to CoA thioesters. Members of the fatty acid transport protein/ very long chain acyl-CoA synthetase (FATP/Acsvl) family are emerging as key players in the trafficking of exogenous fatty acids into the cell and in intracellular fatty acid homeostasis.We have expressed two naturally occurring splice variants of human FATP2 (Acsvl1) in yeast and 293T-REx cells and addressed their roles in fatty acid transport, activation, and intracellular trafficking. Although both forms (FATP2a (Mr 70,000) and FATP2b (Mr 65,000 and lacking exon3, which encodes part of the …

Overexpression Of Galnac-Transferase Galnac-T3 Promotes Pancreatic Cancer Cell Growth, Keisuke Taniuchi, Ronald Cerny, Aki Tanouchi, Kimitoshi Kohno, Norihiro Kotani, Koichi Honke, Toshiji Saibara, Michael A. Hollingsworth

Ronald Cerny Publications

O-linked glycans of secreted and membrane bound proteins play an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation, and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc: polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins, and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in …

Identification And Characterization Of The Anti-Methicillin-Resistant Staphylococcus Aureus Wap-8294a2 Biosynthetic Gene Cluster From Lysobacter Enzymogenes Oh11, Wei Zhang, Yaoyao Li, Guoliang Qian, Yan Wang, Haotong Chen, Yue-Zhong Li, Fengquan Liu, Yuemao Shen, Liangcheng Du

Department of Chemistry: Faculty Publications

Lysobactor enzymogenes strain OH11 is an emerging biological control agent of fungal and bacterial diseases. We recently completed its genome sequence and found it contains a large number of gene clusters putatively responsible for the biosynthesis of nonribosomal peptides and polyketides, including the previously identified antifungal dihydromaltophilin (HSAF). One of the gene clusters contains two huge open reading frames, together encoding 12 modules of nonribosomal peptide synthetases (NRPS). Gene disruption of one of the NRPS led to the disappearance of a metabolite produced in the wild type and the elimination of its antibacterial activity. The metabolite and antibacterial activity were …

Characterizing Rna Dynamics At Atomic Resolution Using Solution-State Nmr Spectroscopy, Jameson R. Bothe, Evgenia N. Nikolova, Catherine D. Eichhorn, Jeetender Chugh, Alexandar L. Hansen, Hashim M. Al-Hashimi

Department of Chemistry: Faculty Publications

Many recently discovered non-coding RNAs do not fold into a single native conformation, but rather, sample many different conformations along their free energy landscape to carry out their biological function. Unprecedented insights into the RNA dynamic structure landscape are provided by solution-state NMR techniques that measure the structural, kinetic, and thermodynamic characteristics of motions spanning picosecond to second timescales at atomic resolution. From these studies a basic description of the RNA dynamic structure landscape is emerging, bringing new insights into how RNA structures change to carry out their function as well as applications in RNA-targeted drug discovery and RNA bioengineering.

Corrosion Rate Trajectories Of Concreted Iron And Steel Shipwrecks And Structures In Seawater— The Weins Number, Donald L. Johnson, D. J. Medlin, L. E. Murphy, J. D. Carr, D. L. Conlin

Department of Chemistry: Faculty Publications

The Weins number (Wn) concept is proposed to predict the long-term corrosion rate of wrought iron and steel in seawater for variable marine environments. Plotted as a function of reciprocal absolute temperature, Weins numbers generate a linear plot from which the corrosion rates are calculated when temperature, oxygen concentration, and concretion thickness are known. Application of the theory of absolute reaction rates is described.

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 …

Development, Validation And Application Of Uhplc-Ms/Ms Methods For The Detection Of Veterinary Drug Residues In Food Of Animal Origin, Michelle Whelan

Theses

Ultra high pressure liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-MS/MS) technology was utilized for the development of analytical methods for the detection of veterinary drug residues in foods of animal origin. Initial work focused on the development of the mass spectrometry (MS) method for the detection of the analytes of interest and subsequent chromatographic separation. The MS method was optimised to detect both positively and negatively ionised analytes from different classes in a single injection in a 13 minute run time at μg kg^-1levels.

Sample preparation procedures were modified to extract the residues from muscle and …

Sol-Gel Resorcinarene Sorbent For Capillary Microextraction Coupled To Gas Chromatography, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

For the first time, octahydroxyl methylresorcinarene with four hexyl groups on the lower rim was utilized in the in-situ preparation of a silica-based sol-gel organicinorganic hybrid coating for sample preconcentration by capillary microextraction (CME). Tetraethoxysilane (TEOS) was chosen as a sol-gel precursor to create a crosslinked sol-gel network via acid-catalyzed hydrolytic polycondensation reactions. Sol-gel chemistry helped in the in situ preparation of resorcinarene-containing extraction phase in the form of a surface coating. It also provided an effective means to chemically bind the coating to the inner surface of fused silica capillary via condensation of the hydroxyl groups in the sol-gel …

The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: A Novel Molecular Parameter To Evaluate The Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments., Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The organic matter (OM) fraction of estuarine sediments is often distinctive and thus diagnostically useful in determinations of sedimentary provenance. Among the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117). …