Chemistry Commons^™

Cerumen Composition By Flash Pyrolysis-Gas Chromatography/Mass Spectrometry, Craig N. Burkhart, Michael A. Kruge, Craig G. Burkhart, Curtis Black

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Objective: To assess the chemical composition of cerumen by flash pyrolysis-gas chromatography/mass spectrometry.

Study Design: Collected earwax specimens were fractionated into residue and supernatant by means of deoxycholate. This natural bile acid produces significantly better disintegration of earwax in vitro than do presently available ceruminolytic preparations, and also has demonstrated excellent clinical results in vivo to date.

Patients: The sample for analysis was obtained from a patient with clinical earwax impaction.

Results: The supernatant is composed of simple aromatic hydrocarbons, C₅-C_{l 7} straight-chain hydrocarbons, a complex mixture of compounds tentatively identified as diterpenoids, …

Production Of A Novel Copper-Binding Ligand By Marine Synechococcus (Cyanobacteria) In Response To Toxic Concentrations Of Copper, Arunsi C. Brown, Andrew S. Gordon

Virginia Journal of Science

Marine Synechococcus spp. are extremely sensitive to copper toxicity. Some strains have been shown to produce high-affinity, extracellular ligands of unknown structure which form complexes with free cupric ion. They are also known to produce metallothioneins (MT) in response to cadmium and zinc stress. In the present study, marine Synechococcus PCC 73109 (Agmenellum quadruplicatum BG-1) (Van Baalen) was exposed to three concentrations of CuSO₄ for various times. Size exclusion chromatography, atomic absorption spectrophotometry, and reverse phase HPLC were used to isolate an intracellular copper binding ligand of low molecular weight (< 6,500 Da). The ligand was detected after exposure to ≥ 8 μM CuSO₄ for 2 hr in BG-11 medium. …

Use Of Py-Gc/Ms Analysis Techniques In Animal Waste Management: A Preliminary Survey Of Dairy Manures, Daniel L. Vaughn, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The increasing practice of industrial-scale agriculture tends to concentrate large masses of animal waste in relatively compact areas, potentially leading to excessive release of polluting nutrients into waterways during major storms. Anaerobic treatment conditions are generally favored to conserve nitrate N as an agricultural commodity. However, overall N contents in waste are often in excess of crop fertilization needs: storing excess N in soluble nitrate form increases pollution potential. Thus the perceived needs of agriculture and society-at-large become at odds. Organic nitrogen forms (e.g., proteins) are more environmentally stable and are less subject to unintentional release. Although U.S. farmers tend …

Analysis Of Loratadine By Potentiometry And Reverse-Phase High Performance Liquid Chromatography, Kian Yong Puen

Student Works (2000-2009)

A non-aqueous titration method was developed to assay Loratadine bulk active and a High Performance Liquid Chromatography (HPLC) method was developed to determine Loratadine's manufacturing impurity. The HPLC method was also suitable for simultaneously assay and related substance determination of Loratadine pharmaceutical preparations. In the tritation method, glacial acetic acid was chosen as an amphiprotic solvent. Loratadine ionised in glacial acetic acid; the conjugated base of acetic acid (Ac·), was then titrated with standardised perchloric acid. The method was validated found to be precise, linear and robust. Reverse-phase HPLC method using a Novapak Cl8 column with a CH3CN: I0mM K2HPO4 …

Impedance Feedback Control For Scanning Electrochemical Microscopy, David O. Wipf, Mario A. Apuche-Avlles

CAS Publications

A new constant-distance imaging method based on the relationship between tip impedance and tip-substrate separation has been developed for the scanning electrochemical microscope (SECM). The tip impedance is monitored by application of a high frequency ac voltage bias between the tip and auxiliary electrode. The high frequency ac current is easily separated from the dc level faradaic electrochemistry with a simple RC filter, which allows impedance measurements during feedback or generation/collection experiments. By employing a piezo-based feedback controller we are able to maintain the impedance at a constant value and, thus, maintain a constant tip-substrate separation. Application of the method …

Development Of Amperometric Enzyme Electrodes For Glucose And Hypoxanthine., Eilish Broderick

Theses

This thesis is concerned with the immobilisation of enzymes on electrosynthesised poly (o- phenylenediamine) membranes for use on amperometric electrodes. The thesis opens with a discussion of the basic principles of enzymology and a review of a diverse range of biosensors, followed by a consideration of amperometry as governed by the Cottrell equation.

Glucose oxidase and horseradish peroxidase were co-immobilised in poly (o-phenylenediamine) on platinum electrodes at + 0.6 V versus Ag/AgCl. Using this approach the enzymes are entrapped in a strongly adherent, highly reproducible thin membrane, of thickness approximately 10 nm. This one-step procedure produces a glucose sensor with …

Analysis Of Wine For Penicillin, Gary Morris, James Yuan, Roy Williams

Chemistry & Biochemistry Faculty Publications

This study addresses the question of whether the antibiotic Penicillin, which is produced by the common mold Penicillium notatum, could possibly become a contaminate of wine during the fermentation process. The significance of this study is related to the potential health effects this agent might produce in those consumers who have an allergic response to Penicillin. It has been estimated that between 6% and 8% of the American population is subject to this type of allergic response. A method is developed for the detection of penicillin in wines using high-pressure liquid chromatography. We demonstrate that penicillin G hydrolyzes rapidly …

Application Of Gc-Fid And Gc-Ms In The Analysis Of Residue Level Of Phthalate Esters Along The Klang River, Maheschandar Biaspal

Student Works (2000-2009)

"Phthalate Esters" ("PEs") are considered as major industrial wastes that can cause pollution in the river water. A study of determination of the PEs in the Klang River water by the application of "Gas Chromatography'' ("GC'') with "Flame-Ionisation Detector" ("FID") will be carried out in this project. "Mass-Selective Detector" ("GC-MSD") will be used in the identification of phthalates compoW1d. A BP-5 non-polar capillary column will be used for the river water analysis. The river water will first be separated by a liquid-liquid extraction with an organic solvent. Toe extracts will then be subjected to a clean-up procedure to separate out …

Characterization Of Solvent-Extractable Hydrocarbons From Airborne Particulates And Street Dust Of Kuala Lumpur, Nasr Yousef M. J. Omar

Student Works (2000-2009)

The solvent-extractable hydrocarbons were identified in PM 10 airborne particles and roadside soil particles collected at eight locations in the city center and the suburb of Kuala Lumpur, Malaysia during the period from November 1998 to January 1999. Airborne particles were collected using high-volume PM1o sampler on glass fiber filters over 24 h average sampling period. After ultrasonic agitation with dichloromethane, the extracts were concentrated and fractionated on an alumina-silica column into three major fractions (aliphatics, aromatics and polar compounds). The aliphatics and aromatics fractions were then subjected to gas chromatography-mass spectrometric (GCMS) analysis. The major hydrocarbons identified in these …

A Study Of Monitoring Corrosion Of Metal Via An Optic Waveguide Sensing Method, Xue-Ming Li, Wei-Ming Chen, Shang-Lian Huang, Na Zhang, Zong-Qing Huang

Journal of Electrochemistry

An optical wave guide sensing method was proposed for monitoring corrosion of metal in outdoors steel structures. Replacing the cladding of wave-guide with metal film in a particular location, the method takes the metal film as the corrosion sensitive film. The experiment of waveguide sensor was carried out on a 721 colorimetric vessel, with which the soution is held in itself and the light is propagated in its sidewall. A Fe-C alloy film was electroplated onto the inner sied of vessel to form the corrosion sensitive film. The structure of the Fe-C alloy film was studied by XRD, EDX and …

Studies Of Electrochemical Impedance Spectroscopy On Coated Steel With Artificial Defect, Zhi-Gang Zhang, Zhi-Jun Gu, Yong-Gui Liao, Qi-Long Guo, Fang-Teng Su, Yan-Zhen Chen

Journal of Electrochemistry

Electrochemical Impedance Spectroscopy (EIS) was applied to rapidly evaluate the performance of organic coatings and the characterization of the protective properties of anticorrosive pigments in the presence of artificial defect in organic coatings. The results showed that artificial defect method can rapidly evaluate the performance of coatings and discriminate whether the pigments in the coatings have inhibitive.

A Study Of The Adsorption Behaviors On The Surface Of Gold Electrode By In-Situ Electrochemical Raman Spectroscopy, Xia-Qin Wu, Xiao-Wei Cao, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang

Journal of Electrochemistry

The results of in-situ measurements with Raman spectroelectrochemical thchnique on bare gold electrode and adenine modified gold electrode were reported. The adsorption behaviors of adenine and superoxide dismutase (SOD) and their interactions with gold electrode were analyed. The mechanism of promoted electron transfer process of SOD in the presence of adenine at gold electrode surface is discussed.

Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I. Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L^-1 NaOH+0.1 mol·L^-1 CH₃CH₂OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH₃COO^-, only very small amount of CH ³CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

Biogeochemistry And Contaminant Geochemistry Of Marine And Estuarine Sediments, New Haven, Connecticut (Usa), Michael A. Kruge, Gaboury Benoit

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The urbanized shore areas of Long Island Sound in the vicinity of New Haven, Connecticut (USA) have a long history of exposure to point and non-point sources of pollution, New Haven having been one of the birthplaces of the industrial revolution. As an unintended consequence of such activities, the region's sedimentary systems have incorporated a complex mixture of organic and inorganic contaminants. With its long and varied pollution history and the multiplicity of sedimentary environments (fluvial, estuarine, intertidal, marsh, etc.) present in a compact geographical area, the region is ideal natural laboratory for field testing new contamination assessment techniques. The …

Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise

Chemistry & Biochemistry Theses & Dissertations

As early as 1950, Raman spectroscopy was proposed as a method to determine aromatics and olefins in hydrocarbon mixtures. Until recently, extensive use of Raman spectroscopy in the characterization of hydrocarbons has not been practical due to several limitations. One early limitation to Raman analysis was the absence of a high intensity and stable excitation source. This problem has been overcome with the advent of lasers. Another limitation was the presence of fluorescence in hydrocarbon fuels when excited by visible lasers. However, the development of Fourier-transform Raman spectrometers now allows Raman spectra to be collected using near-IR lasers (e.g …

The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo

Journal of Electrochemistry

A linear polarization method was applied to measure corrosion rate of reinforcing bar of concrete in situ. Generally in the experiment, the area and shape of the reinforcing bar as a working electrode can be changed and adjusted according to our needs. But polarization area cannot be defined when reinforcing bar is polarized in situ, so that a real R_p can't be obtained. Thus the purpose of present work is to improve the measurement system. We used the double-ring auxiliary electrodes made by ourselves. The size of the double-ring auxiliary electrodes was adjusted repeatedly until the real polarization area …

Pulse Potential Modulated Electrochemical Gas Sensors, Zhong-Bai Zhou, Liang-Dong Feng, Wen-Jun Liu

Journal of Electrochemistry

The current popular electrochemical gas sensors are mostly stable with regard to their operating states. As a result, the further improvement of sensor charcateristics is restricted by such a "steady state". Based on the transient electrochemistry principle, a kind of all new transient electrochemical multi component gas sensors— "pulse potential modulated electrochemical gas sensors" was established by combining computer controlled fast modulated potential technique with microelectrode method.This novel approach provided a real time and dynamic sensor technique integrated with acquisition, treatment and display of signals for rapid simultaneous detecion of multicomponent gases, as illustrated by the case of monitoring of …

Cyclodextrin Inclusion Complexes Of Betamethasone-Related Steroids Studied Using Hplc, Keith Gerald Flood

Seton Hall University Dissertations and Theses (ETDs)

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Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten

Theses and Dissertations in Biomedical Sciences

The major objective of this research is to examine ion mobility spectrometry as a rapid screening tool for specific application to clinical chemistry research and laboratory use. Methodology was developed for target analytes representing several classes of physiologically active substances, including anesthetics, illicit drugs, and their metabolites. The IMS characteristics of animal tissues and other compounds such as amino acids and proteins were determined. Quality assurance and control procedures were developed for specific quality data objectives. Criteria were established relating to use of IMS for assessing the precision and accuracy of data, qualitative screening, and semi-quantitative analyses.

It was found …

Study Of The Cathod Of The Amperometric Glucose Sensor, Xiu-Juan Yu, Ding Zhou

Journal of Electrochemistry

The possibility for several kinds of conducting materials used as the cathode of glucose sensor was studied by the cathode polarization curves. It was shown that the titanium coated by RuO₂/TiO₂ is stable to the electrochemical corrosion and it could promote the generation of hydrogen. H₂O₂ could be detected in the electrochemical system constructed by the anode of graphite powder and epoxy resin composite and the cathode of titanium coated by RuO₂/TiO₂ in the potential range of 0.6V～0.8 V. It can be used as the cathode of glucose sensor instead of …

A Study For The Data Analysis Of Electrochemical Noise With Wavelet Analysis, Hong-Bo Ding, Bao-Yun Xia, Zhong-Xiao Pan, Chang-Jian Lin

Journal of Electrochemistry

In the process of electrochemical dynamics system, the phenomenon of the random fluctuations of electrochemical parameters (electrode potential, cell current, etc.) is called “Electrochemical Noise”(ECN). Wavelets analysis is one new data analysis technique which has undergone a breakthrough in the area of mathematics and singnal processing in recent years. In this paper, the technique of continuous wavelet transform has been employed to investigate electrochemical noise data, and the chaotic nature of corrosion process has been manifested.

Retention Of Ionizable Compounds In Hplc, Rosario Lobrutto

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.

Determination Of Diclofenac In Voltalin Tablets By Differential Pulse Voltammetry, Gui-Fen Wang, Yuan-Zhe Piao

Journal of Electrochemistry

Diclofenac, dissolved in a base solution of chlorhydric acid, showed a sensitive oxidation peak at 0.91 V (vs.SCE) when the solution was cyclically swept from +0.6 to +1.2 V(vs.SCE) by differential pulse voltammetry at GCE. There was a good linear relationship between the differential pulse peak current and the concentraion of diclofenac in the range from 5.0×10^-7 to 6.0×10^-6 mol/L, and the relative standard deviation is 3.5%(n=10). When determining the content of diclofenac in voltalin tablets, we have got the same results by this method as ultraviolet spectrophotometry.

Determination Of Thermal Maturity And Organic Matter Type By Principal Components Analysis Of The Distributions Of Polycyclic Aromatic Compounds, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The thermal maturity and organofacies sensitivity of polycyclic aromatic compound (PAC) distributions was explored by examination of the aromatic fractions of solvent extracts from a diverse set of 53 shales, coals and kerogen macerals which have undergone either natural or artificial maturation and which represent all three principal sedimentary organic matter (OM) types. Systematic changes with maturation were observed in the following groups of isomers: tri- and tetramethylnaphthalenes, methyl- and dimethylphenanthrenes, methyl- and dimethyldibenzothiophenes, methylpyrenes, and methylchrysenes. The maturity differences were quantified by mathematical ratios of the relative concentrations of the more thermally stable isomers to the less stable, on …

Octafluoro-Meso Tetraarylporphyrins And Methods For Making These Compounds, Stephen G. Dimagno

Department of Chemistry: Faculty Publications

The novel compounds of the present invention are f-octafluoro-meso-tetraarylporphyrins of formula (I) and their metallic complexes of formula (II):

B-octafluoro-meso-tetraaryl porphyrins are Synthesized by reacting 3,4-difluoropyrrole with an aromatic aldehyde in the presence of boron trifluoride etherate, followed by oxidation. The difluoropyrrole used in this reaction is pro duced by reacting 3,3,4,4-tetrafluoropyrroline or its corre sponding Salt, 3,3,4,4-tetrafluoropyrrolidinium Salt, with a base Such as potassium tert-butoxide. The metalloporphyrins of the present invention are Synthesized by deprontonating B-octafluoro-meso-tetraarylporphyrin ligands and treating Said ligands with metal ions.

Heavily Fluorinated Sugar Analogs, Stephen G. Dimagno

Department of Chemistry: Faculty Publications

Heavily fluorinated Sugar analogs of formula

wherein R₁ is selected from alkyl, alkenyl, aryl, CH₂OH, -CH₂-O-alkyl, -CH₂-O-aryl, -CH₂OPO₃H, -CH₂-O-carbohydrate, -CH₂-NH-peptide, or -CH₂-O-peptide; wherein R₂ is selected from hydroxy, -O-carbohydrate, -NH-peptide,

wherein R₃ is selected from H, halogen, lower alkyl, lower alkenyl, lower haloalkyl, lower haloalkenyl, amino, mono- or di-lower alkylamino; wherein R₄ is Selected from amino, hydroxy, alkoxy, or halogen; and wherein R₅ is H or amino. The compounds of formula (I) are useful as antiviral and antineoplastic agents …

Analysis Of Selected Trace Metals In Water Using Differential Pulse Polarography And Anodic Stripping Voltammetry, Kar Yi Tong

Student Works (2000-2009)

In this project, two types of the electroanalytical methods have been studied, which are the Differential Pulse Polarography_ (DPP) and Differential Pulse Stripping Voltammetry (DPSV). The DPP mode is used to identify the half-wave potential for the metals, including the lead, cadmium, and zinc. The DPP mode is also used to determine the detection limits for the lead, cadmium, and zinc. Meanwhile, the DPSV mode is used to identify the half-wave potential for the metals. The optimum conditions for the DPSV has to be determined, in order to be used to determine the concentrations of the lead, cadmium, and zinc …

Direct Titrimetric Determination And Of Sulphate, Chee Kin Tan

Student Works (2000-2009)

Interference by foreign ions in direct titrimetric determination of sulphate with barium perchlorate using dimethylsulphonazo III (DMSA Ill) as indicator were studied in this research project. The use of certain water miscible solvents as titration medium has enhanced the determination of end-point. Among the methanol, ethanol, n-propanol and acetone used in the investigation, it was found that medium containing 40 to 50% n-propanol or acetone delivered distinct end-points. The effects of nine cations and eight anions were studied in the above sulphate titration. It was found that the interference caused by Li",Na",K",Mg2"·Mn2", Cd2", NH4", CI and Br are not significant. …

Surface Enhanced Raman Spectroscopic Study Of Scn- Adsorbed At The Copper And Gold Nanowire Arrays, Jian-Lin Yao, Guo-Ping Pan, Kuan-Hong Xue, Yong Xie, Jing Tang, Bin Ren, Dong-Mei Sun, Bing-Wei Mao, Zhong-Qun Tian

Journal of Electrochemistry

Two-dimensional arrays of Cu and Au nanowires have been fabricated by template synthesis method, using the anodic aluminum oxidation films as the template. The morphology of the nanowire array was monitored by atomic force microscope (AFM) in the dissolution processes of the alumina film. Based on the probe molecule strategy, the spectral feature of SCN^- adsorbed at the Cu and Au nanowires with different diameters has been investigated by surface enhanced Raman spectroscopy (SERS). The results reveal that the intensity of the SERS bands depends on the length of the exposed nanowires. The C≡N stretching vibration frequency (ν_{CN …}

A Gas Analysis Method For Determining The Perchlorate Current Efficiency And Other Applications, Zhi-Gang Shao, Bao-Lian Yi

Journal of Electrochemistry

A method for determining the current efficiency by means of measuring the flow capacity of the cell gas in a perchlorate cell has been proposed. The perchlorate cell system was equipped with an oxygen cathode or a Na⁺ ion exchange membrane. This method is simple and convenient as well as accurate in the evaluation of the perchlorate current efficiency in the perchlorate cell as compared with the traditional methods of analysis. It is useful in the investigation of electrochemical problems with high perchlorate concentration, as well as for the assessment of electrocatalytic performance of anode materials.With an oxygen cathode …