Digital Commons Network^™

Remote In-Situ Detection Of 2,4,6-Trinitrotoluene And Other Explosives Using Fiber Optics, Yunke Zhang

Doctoral Dissertations

The goal of this research was to develop methods for the in-situ determination of 2,4,6-trinitrotoluene (TNT) and other polynitroaromatic compounds in groundwater. The first approach was to use an adsorbent to preconcentrate TNT for direct determination. Poly(vinyl alcohol) was crosslinked with glutaraldehyde to form a clear gel that is transparent into the ultraviolet. The volume and swelling of the gel can be controlled by varying the amount of glutaraldehyde. The coefficient for TNT partitioning between the gel and water is 1.4. The gel offers important advantages as a matrix for chemical sensor development, but is not suitable for determining TNT …

Development Of A Glucose Sensor Based On Competitive Binding And Laser-Excited Fluorescence, Richard William Bauer

Doctoral Dissertations

An optical glucose sensor has been developed using competitive binding in conjunction with energy transfer. Sensor response is based on competition between glucose and dextran for a limited number of binding sites on the protein concanavalin A (conA). The system is optically monitored using fluorescent donor-acceptor dye pairs labeled to concanavalin A and dextran. When the dyes are sufficiently close, on the order of 50 A, energy is transferred from the donor emission band to the overlapping excitation band of the acceptor. This nonradiative, singlet-singlet transfer of energy enhances the acceptor emission at the expense of donor emission.

In absence …

Development Of An Analytical Method For The Determination Of Extractable Nitroaromatics And Nitramines In Soils, Thomas F. Jenkins

Doctoral Dissertations

An analytical method was developed to determine the concentrations of HMX, RDX, TNB, DNB, tetryl, TNT and 2,4-DNT in soil. The method relies on solvent extraction with analysis by reversed-phase liquid chromatography.

The extraction step was studied in terms of process kinetics and recovery. Two solvents (acetonitrile and methanol) and four extraction techniques (Soxhlet, ultrasonic bath, mechanical shaker and homogenizer-sonicator) were compared. Ultrasonic bath extraction with acetonitrile was selected based on extraction kinetics, overall analyte recovery, sample throughput, and instability of analytes at elevated temperature. The rate of extraction of analytes from field-contaminated soil was shown to be much slower …