Chemistry Commons^™

A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski

Masters Theses

"Alpha hydroxy acids (AHAs) - carboxylic acids with a hydroxyl substitution on the alpha carbon are an important class of molecules. Hydroxy Methyl Thiobutanoic Acid (HMTBA) is an α-hydroxy analog of essential amino acid methionine; it finds extensive use as a feed supplement for avian and bovine species. Efficacy of alpha hydroxy acid uptake is important for nutritional studies and such studies rely on accurate and precise methods for determination of these chemicals in biological samples. Several methods for AHAs determination have been reported, however, the methods are tedious, requiring multiple sample preparation steps. Experiments reported in this thesis were …

One Step Synthesis Of Some 2,5,6-Trisubstituted-1,3-Dioxin-4-Ones, Ahmet Şener, İshak Bi̇ldi̇ri̇ci̇, Hasan Genç, Nuretti̇n Mengeş, Siddik Eski̇noba

Turkish Journal of Chemistry

A number of novel 2,5,6-trisubstituted-1,3-dioxin-4-one derivatives were synthesized via one step reactions between dibenzoylmethane or benzoylacetone and oxalyl chloride in refluxing solvents containing various aldehydes.

Synthesis And Characterization Of Novel Azole Heterocycles Based On 2,5-Disubstituted Thiadiazole, Nadia A. Salih

Turkish Journal of Chemistry

Starting from 2-amino-5-mercapto-1,3,4-thiadiazole (1), a variety of new 1,2,4-triazino[5,4-b][1,3,4] thiadiazole (3), pyrazole (4), [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazole (5), phthalazine-3,6-dione (6), azo derivatives (9), pyrimidine -2,4,6-trione (11), Schiff base (12) and pyrrolidine (13) derivatives have been synthesized. All proposed structures were supported by FT-IR, ^1H-NMR, ^{13}C-NMR elemental analysis, and MS spectroscopic data.

A Hydrogen Ion-Selective Poly(Vinyl Chloride) Membrane Electrode Based On Calix[4]Arene As A Perchlorate Ion-Selective Electrode, Esi̇n Canel, Sevcan Erden, Ayça Demi̇rel Özel, Sahahabuddin Memon, Mustafa Yilmaz, Esma Kiliç

Turkish Journal of Chemistry

A hydrogen ion-selective electrode was prepared using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanometoxy-calix[4]arene and the possibility of its use as a perchlorate ion-selective electrode was investigated using its characteristic of becoming perchlorate sensitive in acidic regions. The electrode of the optimum characteristic had a composition of 1% ionophore, 66% o-NPOE, and 33% PVC. This electrode exhibited a linear response over the range 1.0 \times 10^{-1}-1.0 \times 10^{-5} M of perchlorate with a slope of 48.7 \pm 0.5 mV per p[ClO_4]. The effects of the pH and the membrane composition were also investigated. The lifetime of the electrode was at least 4 months and its response …

Synthesis And Antimicrobial Evaluation Of Novel Di-Triazoles And 4-Arylidene Amino 4,5 Dihydro-1h-[1,2,4] Triazole-5-One Derivatives, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

A series of novel di-[3(thiophen-2-yl-methyl)-4,5-dihydro-1H- [1,2,4]triazole-5-one-4yl]n-alkanes (2a-h) were obtained by the reaction of N'-1-ethoxy-2-thiophen-2-yl-ethylydene hydrazino carboxylic acid ethyl ester (1) and diamines. Compound 3 was reacted with aldehydes and 4-(arylidene-amino)-3-thiophen-2-yl-methyl-4,5-dihydro-1H-[1,2,4] triazole-5-ones (4, 5, and 8) with Schiff base character were synthesized. (4-(arylidene-amino)-5-oxo-3-thiophen-2-yl-methyl-4,5- dihydro-1H-[1,2,4]triazole-1-yl)-acetic acid ethyl esters (6, 7, and 9) were obtained by the reaction of 4-(arylidene-amino)-3-thiophen-2-yl- methyl-4,5-dihydro-1H-[1,2,4]triazole-5-ones (4, 5, and 8) and ethyl bromoacetate. The structures of the new compounds were inferred through IR, ^1H/^{13}C NMR, elemental analyses, and mass spectral data. Compound 8i was characterized by IR, ^1H/^{13}C NMR, elemental analyses, mass, and X-ray spectral techniques. Geometry optimization …

Determination Of Iridoid Glycosides From Four Turkish Lamium Species By Hplc-Esi/Ms, Funda Nuray Yalçin, Duygu Kaya, İhsan Çaliş, Tayfun Ersöz, Erhan Palaska

Turkish Journal of Chemistry

An HPLC-ESI/MS method that enables fast detection and identification of iridoid glycosides is described. Eleven iridoid glycosides known to occur in the genus Lamium-lamalbide, sesamoside, 6-\beta-OH ipolamiide, shanzhiside methyl ester, dehydropenstemoside, barlerin (= 8-O-acetylshanzhiside methyl ester), 6-O-syringyl-8-O- acetylshanzhiside methyl ester, lamerioside, lamiide, eriobioside, and ipolamiide, were identified by means of their retention time and ESI/MS data. This method was successfully applied to the identification of the iridoid composition of the n-butanol extracts of Lamium eriocephalum Bentham subsp. eriocephalum, L. garganicum L. subsp. pulchrum R. Mill, L. garganicum L. subsp. laevigatum Arcangeli, and L. purpureum L. var. purpureum from the Turkish …

The Kinetics And Mechanism Of Ruthenium(Iii)-Catalyzed Oxidation Of Tris(2-Amino Ethyl)Amine By Hexacyanoferrate(Iii) In Aqueous Alkaline Medium, Radhey Mohan Naik, Abhishek Srivastava, Amit Kumar Verma

Turkish Journal of Chemistry

The kinetics of ruthenium(III)-catalyzed oxidation of TREN, i.e. tris(2-amino ethyl)amine(3-hydrochloride) by an outer sphere electron transfer oxidant, potassium hexacyanoferrate(III), was investigated spectrophotometrically in aqueous alkaline medium. The extent of the reaction was followed by registering a decrease in absorbance at 420 nm (\lambda_{max} of Fe(CN)_6^{3-}) due to its consumption as a function of [OH^-], ionic strength, [Fe(CN)_6^{3-}], [TREN], and temperature by varying only one variable at a time and keeping all other variables constant. The rate data indicate that the reaction exhibited first order dependence in [oxidant] and at a lower concentrations of reductant. The overall reaction follows second order …

On-Line Incorporation Of Cloud Point Extraction In Flame Atomic Absorption Spectrometric Determination Of Silver, Nasser Dalali, Nasrin Javadi, Yadvendra Kumar Agawal

Turkish Journal of Chemistry

A cloud point extraction method was incorporated into a flow injection system, coupled with flame atomic absorption spectrometry, for determination of trace amounts of silver. The analyte in the aqueous solution was acidified with 0.2 mol L^{-1} sulfuric acid and complexed with dithizone. The cloud point extraction was performed using the non-ionic surfactant Triton X-114. After obtaining the cloud point, the surfactant-rich phase containing the dithizonate complex was collected in a mini-column packed with cotton wool. Then the complex was eluted by passing THF through the column and silver content was determined by flame atomic absorption spectrometry. All the chemical …

Studies On The Chemical Constituents Of Thymus Serpyllum, Shahid Aziz, . Habib-Ur-Rehman

Turkish Journal of Chemistry

Phytochemical investigations on the methanolic extract of Thymus serpyllum resulted in the isolation of 2 new compounds, 3-ketopentatriacontanoic acid (1) and 27-ketotriacontanol (2). The extract also afforded 3 known compounds, 3 \beta-hydroxyolean-12-en- 28-oic acid (3), 3-O-\beta-D-glucopyranosyl-sitosterol (4), and dihydroursonic acid (5), detected for the first time from Thymus serpyllum. The structures of the new compounds were elucidated by spectroscopic methods, while the known compounds were identified on the basis of their spectral data and literature evidence. The hexane and ethyl acetate soluble portions of the methanolic extract showed significant antifungal activity, whereas the chloroform soluble portion and the remaining methanol …

Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ

Turkish Journal of Chemistry

1,4'-Diazaflavone pigment (2) was synthesized by a simple environmentally friendly microwave-assisted one-pot method for the cyclization of 2'-amino (E)-4''-aza-chalcone (1) under solventless conditions using K-10 clay. In addition, 10 new N-alkyl (C_{5-12, 14-15}) substituted 1,4' -diazaflavonium bromide pigments (3-12) were prepared from compound 2 or directly from compound 1, with corresponding alkyl halides in acetonitrile under reflux. The anti-microbial activity of compounds 1-12 was tested. The N-alkyl substituted 1,4' -diazaflavonium bromides (3-12) showed good antimicrobial activity against the gram-positive bacteria tested with minimal bactericidal concentration (MBC) values for the reference antibiotic kanamycin. The optimum length of the alkyl chain for …

Reduced Acute Inflammatory Responses To Microgel Conformal Coatings, Amanda W. Bridges, Neetu Singh, Kellie L. Burns, Julia E. Babensee, L. Andrew Lyon, Andrés J. García

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Implantation of synthetic materials into the body elicits inflammatory host responses that limit medical device integration and biological performance. This inflammatory cascade involves protein adsorption, leukocyte recruitment and activation, cytokine release, and fibrous encapsulation of the implant. We present a coating strategy based on thin films of poly(N-isopropylacrylamide) hydrogel microparticles (i.e. microgels) cross-linked with poly(ethylene glycol) diacrylate. These particles were grafted onto a clinically relevant polymeric material to generate conformal coatings that significantly reduced in vitro fibrinogen adsorption and primary human monocyte/macrophage adhesion and spreading. These microgel coatings also reduced leukocyte adhesion and expression of pro-inflammatory cytokines (TNF-alpha, IL-1 beta, …

Activation Energy Of Surface Diffusion And Terrace Width Dynamics During The Growth Of In (4×3) On Si (100) - (2×1) By Femtosecond Pulsed Laser Deposition, M. A. Hafez, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The nucleation and growth of indium on a vicinal Si (100) - (2×1) surface at high temperature by femtosecond pulsed laser deposition was investigated by in situ reflection high energy electron diffraction (RHEED). RHEED intensity relaxation was observed for the first ∼2 ML during the growth of In (4×3) by step flow. From the temperature dependence of the rate of relaxation, an activation energy of 1.4±0.2 eV of surface diffusion was determined. The results indicate that indium small clusters diffused to terrace step edges with a diffusion frequency constant of (1.0±0.1) × 10¹¹ s^-1. The RHEED specular …

The Application Of Lc-Ms Technologies For The Detection Of Triazine Herbicides In Water, Michael Cahill

Theses

The triazine herbicides, including, simazine (6-chloro-N,N’-diethyl-1,3,5-triazine-2,4- diamine), atrazine (2-chloro-4-ethylamino-6-isopropylamino-l,3,5-triazine) and cyanazine were developed as selective weed killers. Their design function is to disrupt the photosynthesis of broad-leafed plants. In the intensive production of grasses (e.g. wheat, cereals, etc.) broad-leafed plants growing in the grass production area are economically costly, competitors with the grasses for nutrients; their removal is facilitated by triazines herbicides and simazine and atrazine are the predominant compounds used. Significant amounts of triazine herbicides are consumed by the agricultural industry each year. However, due to the indiscriminate use of pesticides/herbicides, traces of herbicides have been found in run-off …

Methods Development In Qualitative And Quantitative Proteomics, Ting Liu

University of Kentucky Doctoral Dissertations

Proteomics based on liquid chromatography coupled to mass spectrometry has developed rapidly in the last decade and become a powerful tool for protein mixtures analysis. LC-MS based proteomics involves four steps, sample preparation, liquid chromatography, mass spectrometry and bioinformatics. Improvements in each step have extended its applications to new biological research areas. This dissertation mainly focuses on method developments in both qualitative and quantitative proteomics.

The first part of this dissertation focuses on qualitative analysis of T. gondii Parasitophorous Vacuole Membrane (PVM) proteins, which is very important for T. gondii’s survival. The hypothesis of this study is that proteomic …

Absorption Spectral Slopes And Slope Ratios As Indicators Of Molecular Weight, Source, And Photobleaching Of Chromophoric Dissolved Organic Matter, John R. Helms, Aron Stubbins, Jason D. Ritchie, Elizabeth C. Minor, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

A new approach for parameterizing dissolved organic matter ( DOM) ultraviolet-visible absorption spectra is presented. Two distinct spectral slope regions ( 275-295 nm and 350-400 nm) within log-transformed absorption spectra were used to compare DOM from contrasting water types, ranging from wetlands (Great Dismal Swamp and Suwannee River) to photobleached oceanic water ( Atlantic Ocean). On the basis of DOM size-fractionation studies ( ultrafiltration and gel filtration chromatography), the slope of the 275-295- nm region and the ratio of these slopes (S_R; 275-295- nm slope : 350-400- nm slope) were related to DOM molecular weight ( MW) and …

Technical Note: Molecular Characterization Of Aerosol-Derived Water Soluble Organic Carbon Using Ultrahigh Resolution Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, A. S. Wozniak, J. E. Bauer, R. L. Sleighter, R. M. Dickhut, Patrick Hatcher

Chemistry & Biochemistry Faculty Publications

Despite the acknowledged relevance of aerosol-derived water-soluble organic carbon (WSOC) to climate and biogeochemical cycling, characterization of aerosol WSOC has been limited. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was utilized in this study to provide detailed molecular level characterization of the hi(,h molecular weight (HMW; m/z>223) component of aerosol-derived WSOC collected from rural sites in Virginia and New York, USA. More than 3000 peaks were detected by ESI FT-ICR MS within a m/z range of 223-600 for each sample. Approximately 86% (Virginia) and 78% (New York) of these peaks were assigned molecular formulas …

Designing Surface Chemistries For In Situ Afm Investigations Of Biomolecular Reactions With Proteins At The Nanoscale, Johnpeter Ndiangui Ngunjiri

LSU Doctoral Dissertations

In situ atomic force microscopy (AFM) characterizations and lithography can be applied to investigate the orientation, reactivity and stability of protein molecules adsorbed on nanostructures of self-assembled monolayers at near-physiological conditions. Automated nanografting was used to fabricate regular arrays of nanopatterns of ù-functionalized n-alkanethiols with designated terminal chemistries. After writing nanopatterns, protein binding occurs selectively on carboxylate-terminated nanopatterns via covalent bonds that are formed using N-ethyl-N'(dimethylaminoporpyl)-carbodiimide and N-hydroxysuccinimide activation. The amine groups of lysine residues of proteins bond covalently to nanopatterns of carboxylate-terminated alkanethiol self-assembled monolayers, to form a robust surface attachment for sustained contact-mode AFM imaging during biochemical reactions. …

Bioanalytical Methods For Studies Of Homocysteine And Novel Cardiovascular Disease Indicators, Arther T. Gates

LSU Doctoral Dissertations

This dissertation explores the development of analytical methods for studies of CVD biomarkers and related biomolecular indicators. Initially, spectroscopic studies were conducted to investigate the chemical reactivity of homocysteine (Hcy), an independent CVD risk factor and serological biomarker. Consequently, we proposed an alternate theory for in vivo Hcy clearance based on spontaneous pyridoxal tetrahydrothiazine (PT) formation from Hcy and pyridoxal. The validity of PT-assisted Hcy clearance was further evaluated by use of capillary electrophoretic methods, which allowed rapid monitoring of protein oligomerization in PT-protein reaction mixtures. The results of these studies suggest that PT formation is a plausible mechanism for …

Synthesis And Surface Characterization Of Silica-Polypeptide Composite Particles, Erick Isael Soto-Cantu

LSU Doctoral Dissertations

The synthesis and sequential surface characterization of silica-polypeptide composite particles is described. Nearly monodisperse colloidal silica cores were obtained by the alkaline hydrolysis of tetraethyl orthosilicate (TEOS). The hydrodynamic radius can be easily controlled in the range of ƒî 20-140 nm by the water/TEOS ratio in the starting reaction mixture. The surface of the synthesized silica cores was further passivated/functionalized (P/F) by a mixture of (3-aminopropyl) trimethoxysilane (APS) and methyl-trimethoxysilane (MTMS). The amino groups were quantified using UV-Vis spectrometry after reaction with ninhydrin. The use of zeta potential measurements of the P/F silica particles at low pH is presented as …

Exploration Of New Ternary Gallides And Investigation Of Their Structure-Property Relationships, Jung Young Cho

LSU Doctoral Dissertations

This dissertation focuses on the investigation of new ternary intermetallic gallides, which may exhibit exotic physical properties such as heavy-fermion behavior, large magnetoresistance, and even superconductivity. In particular, the Ln-Cu-Ga (Ln = lanthanides) system has been systematically investigated by changing a reaction ratio and/or using a different temperature profile to optimize desired phases. Single crystals of Ln2MGa12 (Ln = La, Ce; M = Ni, Cu) have been synthesized using Ga flux and compared to their Pd analogues. Interestingly, Ce2MGa12 (M = Ni, Cu) show enhanced Sommerfeld coefficient of ¡Ö 191 mJmol-1K-2 and ¡Ö 69 mJmol-1K-2 for Ni and Cu compounds, …

Methods In Industrial Biotechnology For Chemical Engineers, Florentin Smarandache, W.B. Vasantha Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

Industrial Biotechnology is an interdisciplinary topic to which tools of modern biotechnology are applied for finding proper proportion of raw mix of chemicals, determination of set points, finding the flow rates etc., This study is significant as it results in better economy, quality product and control of pollution. The authors in this book have given only methods of industrial biotechnology mainly to help researchers, students and chemical engineers. Since biotechnology concerns practical and diverse applications including production of new drugs, clearing up pollution etc. we have in this book given methods to control pollution in chemical industries as it has …

Novel Approach For Synthesis Of 2:1 Permethylated Β-Cyclodextrin–C60 Conjugate, Zhu Guan, Yali Wang, Yong Chen, Yongmin Zhang

Department of Chemistry: Dissertations, Theses, and Student Research

Amphiphilic cyclodextrin–fullerene conjugates have potential biological activity, due to their water solubility. In order to study the influence of the linker of these conjugates on solubility and aggregation, a permethylated β-cyclodextrin–C₆₀ conjugate with a short linker –(CH₂)₂NHCO–, which is attached to the secondary face of β-cyclodextrin was synthesized. Its solubility in water and its UV spectrum in CH₂Cl₂ and water were investigated.

Systematic Synthesis And Study Of The Structure-Property Relationships Of Arylene Vinylene Polymers., Patrick Lynch

Doctoral

Much is known about the electronic, vibrational and steric effects resulting from the addition of differing organic functional groups as side chains, to the parent conjugated polymer. However the same cannot be said about the substitution of constituents of the polymer backbone itself. To this end a study is presented here which systematically studies the effects of naphthalene and anthracene substitution of the properties of poly phenylene vinylene (PPV) derivative conjugated polymers. The synthesis by the Witting-Horner reaction of derivatives is presented whereby the phenylene units of the PPV structure are methodically substituted by naphthylene and anthrylene units to form …

Design And Synthesis Of Small-Molecule Inhibitors As Anti-Malarial And Anti-Serpin Agents, Maria Mirela Puscau

Master's Theses and Doctoral Dissertations

This work describe the design, synthesis and evaluation of small-molecule inhibitors of two different biological targets: Plasmodium falciparium, the most virulent malarial parasite in humans, and plasminogen activator inhibitor-1 (PAI-1), an endogenous serine proteases inhibitor implicated in a wide range of biological processes. Malaria is one of the top global health threats, and there is a great need for developing effective new chemotherapies. PAI-1 is a major component in the regulation of the plasminogen activation system, and the overexpression of this protein has been implicated in a number of conditions, such as thrombosis, atherosclerosis, and myocardial infarction. The research …

Laser Surface Thermal Lensing (Stl): An Optical Method For Surface Analysis Of Glass Transition Effects In Transparent Polymers, Nandita Prasad

Master's Theses and Doctoral Dissertations

Absorption of energy from a modulated laser beam by a transparent substrate leads to cyclic thermal expansion and contraction of the surface at the pump beam focus. This minute distortion of the surface forms a transient optical lens structure, which can be monitored by the changes it induces in a second laser beam reflected at an angle off the same focal point. The Surface Thermal Lensing (STL) technique is based on detecting the modulated interference pattern that results from interaction of the probe beam wavefront as it reflects from both the flat surface surrounding the transient lens and the curved …

Application Of Impedance Spectroscopy To The Study Of Dithiocarbamate Species On Au Surfaces: Effects Of Aqueous Cu²⁺ And Mg²⁺ Ions, Tom Riha

Master's Theses and Doctoral Dissertations

Self-assembled monolayers (SAM) of dithiocarbamate ligands were formed on the Au surface of an interdigitated electrode (IDE) array by reaction of amines with CS₂ in H₂O/CH₃OH solutions. Impedance spectroscopy was used to probe for the presence of each SAM as they were individually applied to the surface of the IDE by examining differences in collected impedance data after each step of the chemical application sequence. The impedance behavior of the SAM’s were then studied in the presence of aqueous Cu²⁺ and Mg2+ ions. A treated IDE array would, in theory, be able to preferentially …

The Development Of A Novel And Potentially Nondestructive Pretreatment For The Radiocarbon Dating Of Archaeological Artifacts, Mary Ellen Ellis

Master's Theses and Doctoral Dissertations

Because the traditional acid-alkali-acid method for pretreating archaeological artifacts prior to radiocarbon dating is destructive to most materials, the possibility of developing an alternative pretreatment is important to preserving culturally- and historically-significant artifacts. The alkali step usually involves a 1M or higher concentration NaOH wash to remove humic acid contamination. The purpose of this work is to replace the alkali step with an equally effective, yet less harsh treatment. Charcoal soaked in a humic acid standard was used to mimic a contaminated artifact. Residues from treatments with NaOH, phosphate buffer (pH 8), and deionized water were characterized using THM-GC-MS. Preliminary …

The Synthesis Of Water Soluble N-Acyl Chitosan Derivatives For Characterization As Antibacterial Agents, Lakia Monique Champagne

LSU Doctoral Dissertations

Currently, natural polysaccharides are being utilized increasingly in the markets because they exhibit biodegradability, biocompatibility, versatility, and are found abundant in nature. The diversity of natural polysaccharides provides the chemist with a broad spectrum of raw materials that can be used in many biological applications. Chitosan is a natural polysaccharide that possesses excellent biological properties. It has been recognized for its antibacterial activity, in that it is destructive towards the bacterium Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The antibacterial property of chitosan can be enhanced by changing the hydrophobic/hydrophilic nature of the polysaccharide backbone. This research entails …

1-Alkyl-3-Methylimidazolium Bis(Pentafluoroethylsulfonyl)Imide Based Ionic Liquids: A Study Of Their Physical And Electrochemical Properties, Jennifer N. Decerbo

Browse all Theses and Dissertations

Ionic liquids are an attractive possibility for battery electrolytes. Five ionic liquids were synthesized using a 1-alkyl-3-methylimidazolium (XMI+) cation, where the alkyl group was ethyl, propyl, butyl, pentyl, or hexyl, and a bis(pentafluoroethyl-sulfonyl)imide (Beti-) anion. The absorption and desorption of water, conductivities, densities, viscosities, decomposition temperatures, and electrochemical properties were studied. These ionic liquids were found to absorb less water than previously studied ionic liquids with tetrafluoroborate (BF4-) and hexafluorophosphate (PF6-) anions. Their conductivities decreased with longer alkyl chains on the imidazolium cation and were lower than ionic liquids with BF4- as the anion. The densities of the ionic liquids …

Carbonyl Sulfide (Ocs): Large Scale Distributions Over North America During Intex-Na And Relationship To Co2, Lambert Doezema

Chemistry and Biochemistry Faculty Works

An extensive set of carbonyl sulfide (OCS) observations were made as part of the NASA Intercontinental Chemical Transport Experiment-North America (INTEX-NA) study, flown from 1 July to 14 August 2004 mostly over the eastern United States and Canada. These data show that summertime OCS mixing ratios at low altitude were dominated by surface drawdown and were highly correlated with CO2. Although local plumes were observed on some low-altitude flight legs, anthropogenic OCS sources were small compared to this sink. These INTEX-NA observations were in marked contrast to the early springtime 2001 Transport and Chemical Evolution over the Pacific experiment, which …