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Probing The Intermolecular Hydrogen Bonding Of Water Molecules At The Ccl4/Water Interface In The Presence Of Charges Soluble Surfactant, D. E. Gragson, G. L. Richmond Dec 1997

Probing The Intermolecular Hydrogen Bonding Of Water Molecules At The Ccl4/Water Interface In The Presence Of Charges Soluble Surfactant, D. E. Gragson, G. L. Richmond

Chemistry and Biochemistry

The molecular structure and hydrogen bonding of water molecules at the CCl4/water interface in the presence of a charged soluble surfactant has been explored in this study using vibrational sum frequency generation. By examining OH stretching modes that are highly sensitive to the local hydrogen bonding environment it is found that water molecules at the CCl4/water interface both in the presence and absence of a charged soluble surfactant are predominantly in a tetrahedral arrangement much like the structure ofice. Isotopic dilution studies have been employed to further characterize this icelike interfacial structure. Ablueshift ofapproximately120 cm-1 …


Nucleotide Or Nucleoside Photoaffinity Compound Modified Antibodies, Methods For Their Manufacture And Use Thereof As Diagnostics And Therapeutics, Boyd E. Haley, Heinz Köhler, Krishnan Rajagopalan, Gabriela Pavlinkova Dec 1997

Nucleotide Or Nucleoside Photoaffinity Compound Modified Antibodies, Methods For Their Manufacture And Use Thereof As Diagnostics And Therapeutics, Boyd E. Haley, Heinz Köhler, Krishnan Rajagopalan, Gabriela Pavlinkova

Chemistry Faculty Patents

Sites on antibodies having affinity for photoaffinity compounds, in particular purine or azidopurine containing compounds are taught. These sites provide for the site-specific attachment of nucleotide photoaffinity compounds to antibodies, e.g., ATP- or GTP-analog photoaffinity compounds by photochemical means. These nucleotide photoaffinity compounds may additionally be attached to molecules having a desired therapeutic or diagnostic activity, and the resultant conjugates used as diagnostics or therapeutics.


Proton Nuclear Magnetic Resonance Investigation Of The [2fe-2s]1--Containing “Rieske-Type” Protein From Xanthobacter Strain Py2, Richard C. Holz, Frederick J. Small, Scott A. Ensign Dec 1997

Proton Nuclear Magnetic Resonance Investigation Of The [2fe-2s]1--Containing “Rieske-Type” Protein From Xanthobacter Strain Py2, Richard C. Holz, Frederick J. Small, Scott A. Ensign

Chemistry Faculty Research and Publications

Proton NMR spectra of the Rieske-type ferredoxin from Xanthobacter strain Py2 were recorded in both H2O and D2O buffered solutions at pH 7.2. Several well-resolved hyperfine-shifted 1H NMR signals were observed in the 90 to −20 ppm chemical shift range. Comparison of spectra recorded in H2O and D2O buffered solutions indicated that the signals at −11.4 (L) and −15.5 (M) ppm were solvent-exchangeable and thus were assigned to the two histidine Nε2H protons. The remaining observed signals were assigned based upon chemical shift, T1 values, and one-dimensional …


Studies On Resolution Of Enantiomeric Dialkylaryl Sulfonium Ions With Nmr Shift Reagents, Ea-Ji-Ru Son Dec 1997

Studies On Resolution Of Enantiomeric Dialkylaryl Sulfonium Ions With Nmr Shift Reagents, Ea-Ji-Ru Son

Masters Theses & Specialist Projects

Praseodymium(III) NMR shift reagent, which is an upfield shift reagent, is focused on for assessment of enantiomeric excess and resolution of methyl sulfonium ions. A series of alkylmethylphenylsulfonium ions were analyzed, where alkyl is ethyl (I), butyl(H), octyl (III), and benzyl(IY). The praseodymium agent gives base-lined resolution of the ortho hydrogens resonance for I and IH. All spectra are strongly temperature-dependent. I is shifted more than ED, consistent with a steric effect. Assignments for I were made by gradually increasing the concentration of the shift reagent and by analyzing R-enriched I. Racemization of R-enriched isomer of I by pyramidal inversion …


Elucidation Of The Pathway Required For The Stimulation Of G6pdh Gene Expression By Insulin And Its Mimetics, Asavari Wagle Dec 1997

Elucidation Of The Pathway Required For The Stimulation Of G6pdh Gene Expression By Insulin And Its Mimetics, Asavari Wagle

Masters Theses

Insulin, an anabolic hormone, exquisitely controls cellular physiology and metabolism by modulating the activity of key proteins which regulate metabolic and mitogenic events. Insulin activates several cytosolic proteins via a phosphorylation cascade, but only some of these proteins are required for its specific action. We have elucidated the insulin signal transduction cascade in primary rat hepatocytes, and outlined some of the events that are required for the insulin induced stimulation of glucose-6-phosphate dehydrogenase (G6PDH) gene expression. Using well-characterized and structurally different inhibitors, we show that insulin stimulation of the gene requires the IRS-1/P13K pathway and not the RAS/RAF/MAPK pathway. Gene …


Coordinate Regulation Of G- And C Strand Length During New Telomere Synthesis, Xinqing Fan, Carolyn Mary Price Nov 1997

Coordinate Regulation Of G- And C Strand Length During New Telomere Synthesis, Xinqing Fan, Carolyn Mary Price

Department of Chemistry: Faculty Publications

We have used the ciliate Euplotes to study the role of DNA polymerase in telomeric C strand synthesis. Euplotes provides a unique opportunity to study C strand synthesis without the complication of simultaneous DNA replication because millions of new telomeres are made at a stage in the life cycle when no general DNA replication takes place. Previously we showed that the C-strands of newly synthesized telomeres have a precisely controlled length while the G-strands are more heterogeneous. This finding suggested that, although synthesis of the G-strand (by telomerase) is the first step in telomere addition, a major regulatory step occurs …


Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell Oct 1997

Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some binary lipid mixtures form coexisting liquid phases when spread at the air/water interface. This work describes the pressure–composition phase diagrams of binary mixtures of four unsaturated phosphatidylcholines with dihydrocholesterol. These four binary mixtures have critical compositions of approximately fifty mole percent, and average critical exponents of 0.25±0.07. The data can also be approximated by a regular solution thermodynamic model, yielding parameters for the non-ideality of these mixtures.


Assembly And Disassembly Of Dna Polymerase Holoenzyme, Daniel J. Sexton, Anthony J. Berdis, Stephen J. Benkovic Oct 1997

Assembly And Disassembly Of Dna Polymerase Holoenzyme, Daniel J. Sexton, Anthony J. Berdis, Stephen J. Benkovic

Chemistry Faculty Publications

The complex task of genomic replication requires a large collection of proteins properly assembled within the close confines of the replication fork. The mechanism and dynamics of holoenzyme assembly and disassembly have been investigated using steady state and pre-steady state methods as opposed to structural studies, primarily due to the intrinsic transient nature of these protein complexes during DNA replication. The key step in bacteriophage T4 holoenzyme assembly involves ATP hydrolysis, whereas disassembly is mediated by subunit dissociation of the clamp protein in an ATP-independent manner.


Langmuir Monolayers As Disordered Solids: Strain-State Calculations Applied To Stearic Acid, David R. Swanson, Tadeusz Luty, Craig J. Eckhardt Sep 1997

Langmuir Monolayers As Disordered Solids: Strain-State Calculations Applied To Stearic Acid, David R. Swanson, Tadeusz Luty, Craig J. Eckhardt

Craig J. Eckhardt Publications

This paper presents a calculational procedure to determine the equilibrium phase for a given surface pressure π. The monolayer is treated as orientationally free tails grafted to a two-dimensional net formed by the head groups of the amphiphilic molecules. The head groups form a subsystem with translational degrees of freedom characterized by strain variables in the plane of the surface, and the tail groups compose a subsystem characterized by rotational degrees of freedom. The order in the monolayer derives indirectly from the crystalline head groups through translational–rotational coupling. A stress–strain relation is derived which shows the energetically most favorable path …


Electron Transfer Across A Peptide−Peptide Interface Within A Designed Metalloprotein, Gennady V. Kozlov, Michael Y. Ogawa Sep 1997

Electron Transfer Across A Peptide−Peptide Interface Within A Designed Metalloprotein, Gennady V. Kozlov, Michael Y. Ogawa

Chemistry Faculty Publications

Mechanistic studies of biological electron-transfer (ET) reactions have involved the use of surface-derivatized proteins, protein−protein complexes, and polypeptide-bridged donor−acceptor compounds. These latter studies seek to use well-defined model systems to better define the role of the intervening protein matrix in mediating biological electron transfers. However, whereas many in vivo ET reactions occur across a noncovalent protein−protein interface, the primary role of the peptide spacers found in current model systems is to provide a covalent link between the donor and acceptor sites. As such, these systems are poorly suited to probe the mechanisms of ET reactions occurring across a peptide−peptide interface.


A Fluid In Contact With A Semipermeable Surface: Second-Order Integral Equation Approach, Douglas Henderson, Pawel Bryk, Stefan Sokolowski Aug 1997

A Fluid In Contact With A Semipermeable Surface: Second-Order Integral Equation Approach, Douglas Henderson, Pawel Bryk, Stefan Sokolowski

Faculty Publications

An integral equation approach for a binary hard-sphere mixture interacting with a planar semipermeable wall (membrane) is formulated by using the second-order nonuniform or pair Ornstein–Zernike equation as well as the usual singlet Ornstein–Zernike equation. The results of the pair theory are compared with those obtained from the singlet theory and with computer simulation data. The pair approach is more accurate than the singlet theory.


Emissions From Smoldering Combustion Of Biomass Measured By Open-Path Fourier Transform Infrared Spectroscopy, Robert J. Yokelson, Ronald A. Susott, Darold E. Ward, James J. Reardon, David W. T. Griffith Aug 1997

Emissions From Smoldering Combustion Of Biomass Measured By Open-Path Fourier Transform Infrared Spectroscopy, Robert J. Yokelson, Ronald A. Susott, Darold E. Ward, James J. Reardon, David W. T. Griffith

Chemistry and Biochemistry Faculty Publications

Biomass samples from a diverse range of ecosystems were burned in the Intermountain Fire Sciences Laboratory open combustion facility. Midinfrared spectra of the nascent emissions were acquired at several heights above the fires with a Fourier transform infrared spectrometer (FTIR) coupled to an open multipass cell. In this report, the results from smoldering combustion during 24 fires are presented including production of carbon dioxide, carbon monoxide, methane, ethene, ethyne, propene, formaldehyde, 2-hydroxyethanal, methanol, phenol, acetic acid, formic acid, ammonia, hydrogen cyanide, and carbonyl sulfide. These were the dominant products observed, and many have significant influence on atmospheric chemistry at the …


Age-Dependent Increase In Ortho-Tyrosine And Methionine Sulfoxide In Human Skin Collagen Is Not Accelerated In Diabetes: Evidence Against A Generalized Increase In Oxidative Stress In Diabetes, Mary C. Wells-Knecht, Timothy J. Lyons, David R. Mccance, Suzanne R. Thorpe, John W. Baynes Aug 1997

Age-Dependent Increase In Ortho-Tyrosine And Methionine Sulfoxide In Human Skin Collagen Is Not Accelerated In Diabetes: Evidence Against A Generalized Increase In Oxidative Stress In Diabetes, Mary C. Wells-Knecht, Timothy J. Lyons, David R. Mccance, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

The glycoxidation products Nepsilon-(carboxymethyl)lysine and pentosidine increase in skin collagen with age and at an accelerated rate in diabetes. Their age-adjusted concentrations in skin collagen are correlated with the severity of diabetic complications. To determine the relative roles of increased glycation and/or oxidation in the accelerated formation of glycoxidation products in diabetes, we measured levels of amino acid oxidation products, distinct from glycoxidative modifications of amino acids, as independent indicators of oxidative stress and damage to collagen in aging and diabetes. We show that ortho-tyrosine and methionine sulfoxide are formed in concert with Nepsilon-(carboxymethyl)lysine and pentosidine during glycoxidation of collagen …


Scanning Motions Of An Atomic Force Microscope Tip In Water, Kenichiro Koga, Xiao Cheng Zeng Aug 1997

Scanning Motions Of An Atomic Force Microscope Tip In Water, Kenichiro Koga, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Integral equation techniques are used to study scanning motions of a single-atom tip of the atomic force microscope (AFM) over a rigid, hydrophobic monolayer substrate in water. The calculated force curve is found to be oscillatory, in agreement with recent AFM experiments, which can lead to multiple scanning trajectories for the tip under a constant load. The unique trajectory along which the system is thermodynamically stable is revealed. This study shows that the tip may take a hopping motion over a defect-free substrate due to layering of water molecules between the tip and substrate.


39th Rocky Mountain Conference On Analytical Chemistry Aug 1997

39th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Preliminary program and registration information for the 39th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 3-7, 1997.


Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad Jul 1997

Comparison Of The Dichlorination Of Organic N-Chloramines By Caroate And By Bisulfite: A Kinetic Study, Said H. Lubbad

Chemistry & Biochemistry Theses & Dissertations

Bisulfite is commonly used to dechlorinate chlorinated municipal wastewater. However, several studies suggest that bisulfite is not effective in dechlorinating N-chlorinated amino components of wastewater. The purpose of this study was to investigate the effectiveness of an alternate dechlorinating agent, caroate (peroxysulfate), and to compare its rate of dechlorination of three different types of chloramines with that of bisulfite.

Four N-chlorinated amino compounds were investigated: N-chlorodiethylamine, N­ chloroalanylphenylalanine, N-chloroglycylphenylalanine, and N-[2-(N'-chloroimino)­ propanoyl]phenylalanine. These compounds were selected from different families of N­ chloramines to study the effect of structure on dechlorination by both caroate and bisulfite. At pH …


Nondipole Resonant X-Ray-Raman Spectroscopy: Polarized Inelastic Scattering At The K Edge Of Cl2, J. D. Mills, J. A. Sheehy, T. A. Ferrett, S. H. Southworth, R. Mayer, Dennis W. Lindle, P. W. Langhoff Jul 1997

Nondipole Resonant X-Ray-Raman Spectroscopy: Polarized Inelastic Scattering At The K Edge Of Cl2, J. D. Mills, J. A. Sheehy, T. A. Ferrett, S. H. Southworth, R. Mayer, Dennis W. Lindle, P. W. Langhoff

Chemistry and Biochemistry Faculty Research

Experimental and theoretical studies are reported on the inelastic (Raman) scattering of wavelength-selected polarized x rays from the K edge of gas-phase chlorine molecules. The polarized emission spectra exhibit prominent nondipole features consequent of phase variations of the incident and emitted radiation over molecular dimensions, as predicted by the Kramers-Heisenberg scattering formalism. Issues pursuant to the detection of core-hole localization by resonant Raman scattering from homonuclear diatomic molecules are critically examined. [S0031-9007(97)03486-8]


Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike Jul 1997

Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike

Chemistry & Biochemistry Theses & Dissertations

We investigated the separation of selenoprotein P and extracellular (serum) glutathione peroxidase using a concanavalin A affinity column. We were able to show that the method does not adequately separate serum glutathione peroxidase from selenoprotein P because human glutathione peroxidase binds strongly to the column. We also found that albumin can interfere with measurement serum of glutathione peroxidase activity when hydrogen peroxide is used as the substrate. When t-butyl hydroperoxide was used as the substrate, less than 10% of the measured activity was due to the presence of albumin. We also found that the pH of the elution buffer plays …


Solvent-Induced Interactions Between Hydrophobic And Hydrophilic Polyatomic Sheets In Water And Hypothetical Nonpolar Water, Kenichiro Koga, Xiao Cheng Zeng, Hideki Tanaka Jun 1997

Solvent-Induced Interactions Between Hydrophobic And Hydrophilic Polyatomic Sheets In Water And Hypothetical Nonpolar Water, Kenichiro Koga, Xiao Cheng Zeng, Hideki Tanaka

Xiao Cheng Zeng Publications

Hydrophobic and hydrophilic interactions are two major intermolecular forces between hydrophobic nonpolar and hydrophilic polar sites of macromolecules or materials surfaces in solvents. To further understand these two interactions at the microscopic level, an idealized polyatomic model is devised, which includes hydrophobic, hydrophilic, and partially hydrophilic polyatomic planar square molecular sheets. The hydrophobic molecular sheet is composed of the Lennard-Jones particles while the hydrophilic molecular sheet consists of positive and negative charge sites. In the framework of the extended reference interaction site model integral equation theory the solvent-induced interactions (or the potential of mean forces) between two parallel molecular sheets …


Preparation Of Organometallic Complexed Sugars:  Hetero Diels−Alder Reactivity Of Tricarbonyl(Formyltrimethylenemethane)- Iron, Paul J. Kleindl, William A. Donaldson Jun 1997

Preparation Of Organometallic Complexed Sugars:  Hetero Diels−Alder Reactivity Of Tricarbonyl(Formyltrimethylenemethane)- Iron, Paul J. Kleindl, William A. Donaldson

Chemistry Faculty Research and Publications

No abstract provided.


Synthesis Of Biologically Active Substituted Chalcones, Kiel Steven Hoff Jun 1997

Synthesis Of Biologically Active Substituted Chalcones, Kiel Steven Hoff

Masters Theses

Two different synthetic routes to poly-hydroxylated chalcones are investigated. The wittig synthesis and protection of the hydroxyl functionalities by forming the methyl ether followed by the base catalyzed Claissen-schmidt reaction and then deprotection were investigated. It was demonstrated that the protection-condensation- deprotection route was more efficient. The antiviral activity of 2,2', 4' - trihydroxychalcone against the HIV virus is also presented.


Carboxymethylethanolamine, A Biomarker Of Phospholipid Modification During The Maillard Reaction In Vivo, Jesus R. Requena, Mahtab U. Ahmed, C. Wesley Fountain, Thorsten P. Degenhardt, Sharanya Reddy, Cliff Perez, Timothy J. Lyons, Alicia J. Jenkins, John W. Baynes, Suzanne R. Thorpe May 1997

Carboxymethylethanolamine, A Biomarker Of Phospholipid Modification During The Maillard Reaction In Vivo, Jesus R. Requena, Mahtab U. Ahmed, C. Wesley Fountain, Thorsten P. Degenhardt, Sharanya Reddy, Cliff Perez, Timothy J. Lyons, Alicia J. Jenkins, John W. Baynes, Suzanne R. Thorpe

Faculty Publications

Nepsilon-(Carboxymethyl)lysine (CML) is a stable chemical modification of proteins formed from both carbohydrates and lipids during autoxidation reactions. We hypothesized that carboxymethyl lipids such as (carboxymethyl)phosphatidylethanolamine (carboxymethyl-PE) would also be formed in these reactions, and we therefore developed a gas chromatography-mass spectrometry assay for quantification of carboxymethylethanolamine (CME) following hydrolysis of phospholipids. In vitro, CME was formed during glycation of dioleoyl-PE under air and from linoleoylpalmitoyl-PE, but not from dioleoyl-PE, in the absence of glucose. In vivo, CME was detected in lipid extracts of red blood cell membranes, approximately 0.14 mmol of CME/mol of ethanolamine, from control and diabetic subjects, …


Grand Canonical Monte Carlo And Modified Singlet Integral Equations For The Density Profile Of A Yukawa Fluid Near A Planar Wall, Douglas Henderson, Wilmer Olivares-Rivas, Leo Degreve, Jacqueline Quintana May 1997

Grand Canonical Monte Carlo And Modified Singlet Integral Equations For The Density Profile Of A Yukawa Fluid Near A Planar Wall, Douglas Henderson, Wilmer Olivares-Rivas, Leo Degreve, Jacqueline Quintana

Faculty Publications

Results for the density profile for Yukawa molecules near a hard wall and an exponential attractive wall are presented for Grand Canonical Monte Carlo (GCMC) simulations, for the singlet hypernetted chain (HNC) integral equation and for a modified version of the Lovett–Mou–Buff–Wertheim (LMBW-1) which uses the exact contact value theorem. The results of the standard singlet HNC are quite poor. If the LMBW equation is modified (but still using the bulk direct correlation function) the results at high temperature become reasonable. However, the results at low temperatures, close to the bulk coexistence curve, are only a partial improvement. The contact …


Signal Transduction Pathways In Volvox Carteri, Heide Girardin May 1997

Signal Transduction Pathways In Volvox Carteri, Heide Girardin

Honors Theses

The green alga Volvox carteri exhibits a virtual absence of protein synthesis in the dark, but begins synthesizing proteins necessary for growth and development almost immediately after exposure to the light. The regulation of protein synthesis in this system is known to be translational since extracts prepared in the dark have identical pools and quantities of mRNA as extracts prepared in the light (Kirk and Kirk, 1983). Exploration of the mechanism of translational regulation has led us to consider the importance of signal transduction pathways. By using a variety of commercially available drugs that affect specific components of known signaling …


Celluloid Blackness : Race, Modernity, And The Conflicted Roots Of American Cinema (1915-1939), Lincoln Farr May 1997

Celluloid Blackness : Race, Modernity, And The Conflicted Roots Of American Cinema (1915-1939), Lincoln Farr

Honors Theses

Introduction: "The Problem of the Twentieth Century" In a full page interview in the New York Times on May 29, 1912, the Swiss psychiatrist Dr. Carl G. Jung told the American people, "It seems to me that you are about to discover yourselves. You have discovered everything else-all the land of this continent; all the resources, all the hidden things of nature."Jung used the interview to address the American people, at a moment which he somehow recognized as crucial in the development of human civilization. America, the "tragic" country which he struggled to comprehend, would soon become the harbinger of …


Laser-Initiated Decomposition Products Of Indocyanine Green (Icg) And Carbon Black Sensitized Biological Tissues, John M. Kokosa, Andrzej Przyjazny, Kenneth Eugene Bartels, Massoud Motamedi, Donald J. Hayes, David B. Wallace, Christopher J. Frederickson May 1997

Laser-Initiated Decomposition Products Of Indocyanine Green (Icg) And Carbon Black Sensitized Biological Tissues, John M. Kokosa, Andrzej Przyjazny, Kenneth Eugene Bartels, Massoud Motamedi, Donald J. Hayes, David B. Wallace, Christopher J. Frederickson

Chemistry & Biochemistry Publications

Organic dyes have found increasing use a s sensitizers in laser surgical procedures, due to their high optical absorbances. Little is known, however, about the nature of the degradation products formed when these dyes are irradiated with a laser. Previous work in our laboratories has shown that irradiation of polymeric and biological tissues with CO2 and Nd:YAG lasers produces a host of volatile and semivolatile by-products, some of which are known to be potential carcinogens. This work focuses on the identification of the chemical by-products formed by diode laser and Nd:YAG laser irradiation of indocyanine green (ICG) and carbon black …


Computer Modeling Of Molecular Vibration Frequencies And Its Application To The Modeling Of Silane Compounds, Ryan T. Merrell May 1997

Computer Modeling Of Molecular Vibration Frequencies And Its Application To The Modeling Of Silane Compounds, Ryan T. Merrell

Honors Capstone Projects and Theses

No abstract provided.


Binding Of Cobalt (Iii) To Nucleic Acids Via Reaction With [Co(Nh3)5(Oh2)]3+, David M. Calderone May 1997

Binding Of Cobalt (Iii) To Nucleic Acids Via Reaction With [Co(Nh3)5(Oh2)]3+, David M. Calderone

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.


Synthesis And Characterization Of Modified Silica Gel As An Intermediate In The Generation Of Gaseous Standard Mixtures, M. Prokopowicz, K. Lewandowska, A. Skwierawska, Andrzej Przyjazny, Jan F. Biernat, J. Namiesnik Apr 1997

Synthesis And Characterization Of Modified Silica Gel As An Intermediate In The Generation Of Gaseous Standard Mixtures, M. Prokopowicz, K. Lewandowska, A. Skwierawska, Andrzej Przyjazny, Jan F. Biernat, J. Namiesnik

Chemistry & Biochemistry Publications

A possibility of extending analytical applications of chemically modified silica gels is described. This involves their utilization for the generation of gaseous standard mixtures consisting of methyl chloride as the analyte and nitrogen as a carrier gas to be used for the calibration of the GC-FID system. N-methylmorpholine was chemically bonded to the propylsilylated surface of silica gel forming chloride of an appropriate immobilized compound which, under certain conditions, undergoes thermal decomposition yielding a single, volatile component (methyl chloride). Such a method of generating specific amounts of a standard substance can be used both for a single point calibration and …


Development Of Solid Phase Microextraction Methods For Contraband Drugs, Vangielynn Cruz Tersol Apr 1997

Development Of Solid Phase Microextraction Methods For Contraband Drugs, Vangielynn Cruz Tersol

Chemistry & Biochemistry Theses & Dissertations

The objective of this study is to develop analytical methods for studying contraband drugs at nanogram levels and to demonstrate the utility of the methods. A method which combines solid phase microextraction with ion mobility spectrometry (SPME-IMS) was developed. The SPME-IMS method was used as a rapid screening tool in studying the chemistry of cocaine HCI, heroin HCI, and heroin freebase on surfaces. The total time for sample preparation, reaction, and analysis is approximately seven minutes. Another method that was developed is one that combines solid phase microextraction with gas chromatography (SPME-GC) for the quantitative analysis of cocaine freebase and …