Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Speciation Of Selenium In Serum, Alice Tsapayi-Musapatike
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 …
Evaluation Of Solid Phase Extraction Followed By Supercritical Fluid Elution Of Semi-Volatile Organic Compounds In Toxicity Characteristic Leachates, William Edward Corl Iii
Evaluation Of Solid Phase Extraction Followed By Supercritical Fluid Elution Of Semi-Volatile Organic Compounds In Toxicity Characteristic Leachates, William Edward Corl Iii
Chemistry & Biochemistry Theses & Dissertations
The Environmental Protection Agency (EPA) developed the toxicity characteristic leaching procedure (TCLP) to determine the potential for unknown wastes to leach haz.ardous constituents into the environment. Methods currently being used for the extraction of semi-volatile organic compounds from aqueous TCLP leachates involve acid/base partitioning into methylene chloride. The concentrated extract is then analyzed by gas chromatography/mass spectrometry (GC/MS). The methods are either timeconsuming or labor intensive and they generate significant volumes of haz.ardous wastes themselves. Considering the haz.ards and disposal costs of methylene chloride wastes, great interest has been elicited by the EPA in other extraction techniques which would reduce …
Fabrication And Evaluation Of Boron-Doped Cvd Diamond Microelectrodes, Song Pang
Fabrication And Evaluation Of Boron-Doped Cvd Diamond Microelectrodes, Song Pang
Chemistry & Biochemistry Theses & Dissertations
The electrochemical behavior of boron-doped diamond microelectrodes has been studied in acetonitrile solutions containing two redox couples using cyclic voltammetry. One test system is 1-2.5 mM ferrocene, containing 0.1 M Tetrabutyl ammonium hexafluorophosphate (TBAH). This well-known reversible redox system involves only one electron transfer with little or no change in the solvation sphere and no breakage/formation of chemical bonds. Another test system is a 1 mM S2Mo180644- solution containing 0.1 M HCIO4. This is one of the most complicated redox systems. In the presence of acid, electrons are usually transferred consecutively and …
Development Of Solid Phase Microextraction Methods For Contraband Drugs, Vangielynn Cruz Tersol
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 …
Development Of A Fluorescent Indicator For Inorganic Monochloramine, Xiaojun Dong Zou
Development Of A Fluorescent Indicator For Inorganic Monochloramine, Xiaojun Dong Zou
Chemistry & Biochemistry Theses & Dissertations
Current methods used to determine combined residual chlorine cannot distinguish between inorganic monochloramine (NH2Cl) and organic chloramines. Studies described in this thesis were carried out to develop a novel method of determining the concentration of inorganic monochloramine in aqueous solutions. Based on the observation that the reaction of 3-formyl-1-methylpyridinium chloride (3FMPCl) with NH2Cl produces a solution which is fluorescent, experiments were conducted to characterize the reaction and optimize the experimental conditions. Using the finalized protocol, NH2Cl measurements were made in the presence and absence of organic amines and compared with a commonly used N, …