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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Electrochemical Enzyme Immunoassay Using Sequential Saturation Technique In A 20-Μl Capillary: Digoxin As A Model Analyte, Noriaki Kaneki, Yan Xu, Anu Kumari, H. Brian Halsall, William R. Heineman, Peter T. Kissinger Mar 1994

Electrochemical Enzyme Immunoassay Using Sequential Saturation Technique In A 20-Μl Capillary: Digoxin As A Model Analyte, Noriaki Kaneki, Yan Xu, Anu Kumari, H. Brian Halsall, William R. Heineman, Peter T. Kissinger

Chemistry Faculty Publications

Capillary enzyme immunoassay with flow-injection analysis for digoxin using the sequential saturation technique has been developed. Glass capillary tubes (10 cm × 0.53 mm i.d.) with immobilized digoxin antibody were used as the immunoassay reactor. The product of enzymatic reaction. 4-aminophenol, was detected amperometrically. The digoxin and the labeled digoxin binding reaction with the immobilized digoxin antibody were completed in 2 and 10 min, respectively. Digoxin was determined in a 20-μl sample with a detection limit of 10 pg ml−1 (200 fg or 260 attomoles) and a 3 orders of magnitude range.


Flow Analysis. A Report On The 6th International Conference On Flow Analysis Held In Toledo, Spain, June 8-11, 1994, Julian Tyson Jan 1994

Flow Analysis. A Report On The 6th International Conference On Flow Analysis Held In Toledo, Spain, June 8-11, 1994, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Comparison Of The Maximum Sensitivity Of Different Flow Injection Manifold Configurations: Alternating Variable Search Optimization Of The Iron(Ii)/1,10-Phenanthroline System, Sj Chalk, Julian Tyson Jan 1994

Comparison Of The Maximum Sensitivity Of Different Flow Injection Manifold Configurations: Alternating Variable Search Optimization Of The Iron(Ii)/1,10-Phenanthroline System, Sj Chalk, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Flow Injection Techniques, Julian Tyson Jan 1994

Flow Injection Techniques, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Highly Reactive Forms Of Zinc And Reagents Thereof, Reuben D. Rieke Jan 1994

Highly Reactive Forms Of Zinc And Reagents Thereof, Reuben D. Rieke

Chemistry Department: Faculty Publications

A novel zerovalent zinc species and an organozinc reagent are disclosed. The zerovalent zinc species is directly produced by reaction of a reducing agent on a zinc salt, preferably Zn(CN)2. The organozinc reagent results from the reaction of the zerovalent zinc species and an organic compound having one or more stable anionic leaving groups. These organozinc reagents include a wide spectrum of functional groups in the organic radical, and are useful in a variety of reactions schemes.


Initiation And Study Of Localized Corrosion By Scanning Electrochemical Microscopy, David O. Wipf Jan 1994

Initiation And Study Of Localized Corrosion By Scanning Electrochemical Microscopy, David O. Wipf

College of Arts and Sciences Publications and Scholarship

This paper describes methods to study the initiation and formation of localized corrosion pits on stainless–steel and aluminum samples. These methods are based on the use of a scanned probe microscope, the scanning electrochemical microscope (SECM). The SECM is specifically designed for operation in electrolyte solution and so is uniquely suited for examination of corrosion processes. SECM imaging of a corrosion pit on stainless steel is presented. In addition, the initiation of single pits on aluminum and stainless steel by using the SECM tip to electrogenerate a local source of Cl is described.


Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge Jan 1994

Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Organic matter separated from calcareous sandstone from the upper portion of a deep-water tsunami deposit at Arroyo el Mimbral, Taumalipas (Mexico), which marks the biostratigraphically-defined Cretaceous-Tertiary boundary, consists primarily of fossil charcoal, including semifusinite and pyrofusinite. Analytical pyrolysis-gas chromatography-mass spectrometry revealed the highly aromatic and polyaromatic character of the organic matter assemblage, typical of the products of partial combustion. The organic matter probably originated as terrestrial vegetation that was caught in a firestorm and subsequently transported far offshore in the backwash of a megawave. These data are consistent with the hypothesis of combustion of large masses of vegetation triggered by …


Geochemical Characterization Of Maceral Concentrates From Herrin No. 6 Coal (Illinois Basin) And Lower Toarcian Shale Kerogen (Paris Basin), B Artur Stankiewicz, Michael A. Kruge, John C. Crelling Jan 1994

Geochemical Characterization Of Maceral Concentrates From Herrin No. 6 Coal (Illinois Basin) And Lower Toarcian Shale Kerogen (Paris Basin), B Artur Stankiewicz, Michael A. Kruge, John C. Crelling

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Density gradient centrifugation (DGC) is a physical method for the separation of sedimentary organic matter into its constituents. Using DGC, it is possible to prepare maceral concentrates from a single sample, which are amenable to microanalysis. DGC fractions from a coal sample from the Illinois Basin (Herrin No. 6, Upper Carboniferous) and from the kerogen of a marine shale sample from the Paris Basin (Lower Toarcian) were analyzed by flash pyrolysis-gas chromatography-mass spectrometry, after extraction by CH2Cl2.

Chemical differences between the coal DGC fractions are the easiest to recognize, indicating very distinctive biological precursors. For example, …


Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley Jan 1994

Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Chemical analyses restricted to a single coal maceral permit a focus on rank effects without concern for variations in organic matter type. Vitrinite concentrates of high purity were isolated from coal samples of the Lower Kittanning seam by multi-step density gradient centrifugation, with reflectances ranging from 0.66 to 1.39% Rmax. In addition to the previously recognized losses of phenolic compounds, the vitrinite pyrolyzates exhibit marked increases in relative concentrations of tri- and tetraaromatic hydrocarbons (especially benzo[a]fluorene, methyl-phenanthrenes, methylfluorenes and methylchrysenes) above 0.9% Rmax, i.e., beyond the "second coalification jump" of Teichmüller. Thus, petrographically-recognizable physical transformations are shown …


Serravallian Shales In The Monte Dei Corvi Pelagic Sequence (Ancona, Italy): An Organic Geochemical Perspective, Michael A. Kruge, B Artur Stankiewicz, Alessandro Montanari Jan 1994

Serravallian Shales In The Monte Dei Corvi Pelagic Sequence (Ancona, Italy): An Organic Geochemical Perspective, Michael A. Kruge, B Artur Stankiewicz, Alessandro Montanari

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

In addition to the predominant marly lithologies, the Serravallian-Tortonian sequence at Monte dei Corvi (MDC), south of Ancona, Italy, contains at least 85 thin, dark calcareous shales. Such shales, averaging 14 cm in thickness, comprise 9% of the total Serravallian sequence. Sixteen of them were sampled for a preliminary organic geochemical evaluation. All the MDC shales appear to have been deposited during periodic anoxic events, as demonstrated by the presence of significant quantities of organic matter and authigenic pyrite. The degree of anoxicity (and thus the amount of organic matter preserved) appears to have differed from one event to the …


Direct Determination Of Trace Metals In Saline Water Samples Using Gfaas, Michael Joseph Wassell Jan 1994

Direct Determination Of Trace Metals In Saline Water Samples Using Gfaas, Michael Joseph Wassell

Dissertations, Theses, and Masters Projects

No abstract provided.