John F. Schneider

Evaluation of Gas Chromatography/Matrix Isolation-Infrared Spectroscopy for the Quantitative Analysis of Environmental Samples:

Gas chromatography/matrix isolation-infrared spectrometry (GC/MI-IR) is being applied to many analyses previously done only by gas chromatography/mass spectrometry (GC/MS). Qualitatively, the infrared spectra of matrix-isolated compounds contain much information about their structure. The information obtained from the infrared spectrum is complementary to the information obtained from mass spectrometry. The technique of GC/MI-IR should also be useful as a quantitative detector. In this study, semivolatile priority pollutant mixtures were analyzed quantitatively by GC/MI-IR. Results were compared with results obtained by GC/MS. Calibration curves were obtained on the GC/MI-IR for several semivolatile priority pollutants to measure the precision and linearity of this technique. The results indicated that GC/MI-IR, in its current form, is only suitable for semiquantitative work.

A coulometric iodimetric procedure for measuring the purity of lewisite

A new analytical method for the determination of the purity of CASARM Lewisite samples (Chemical Agent Standard Analytical Reference Materials) has been developed and tested. The method essentially replaces the volumetric iodimetric procedures currently in use with the in-situ electrochemical generation of iodine. Tests on both arsenious acid and Lewisite/CVAA solutions show that the method is capable of achieving high accuracy and precision. Sample preparation and analysis times are considerably less than the current titrimetric method. The coulometric iodimetric method has been shown capable of determining not only total organic trivalent arsenic, but also total trivalent arsenic merely by adjusting the pH. Organic arsenic is determined at pH 4, and total trivalent arsenic at pH 8.

Mercury transformations in chemical agent simulant as characterized by X-ray absorption fine spectroscopy

Chemical analyses of U.S. stockpiled mustard chemical warfare agent show some agent destined for destruction contains mercury [L. Ember, Chem. Eng. News 82 (2004) 8]. Because of its toxicity, mercury must be removed from agent prior to incineration or be scrubbed from incineration exhaust to prevent release into the atmosphere. Understanding mercury/agent interactions is critical if either atmospheric or aqueous treatment processes are used. We investigate and compare the state of mercury in water to that in thiodiglycol, a mustard simulant, as co-contaminants are introduced. The effects of sodium hypochlorite and sodium hydroxide, common neutralization chemicals, on mercury in water and simulant with and without co-contaminants present are examined using X-ray absorption fine spectroscopy (XAFS).

Micro-SHINE Uranyl Sulfate Irradiations at the Linac

Peroxide formation due to water radiolysis in a uranyl sulfate solution is a concern for the SHINE Medical Technologies process in which Mo-99 is generated from the fission of dissolved low enriched uranium. To investigate the effects of power density and fission on peroxide formation and uranyl-peroxide precipitation, uranyl sulfate solutions were irradiated using a 50 MeV electron linac as part of the micro-SHINE experimental setup. Results are given for uranyl sulfate solutions with both high and low enriched uranium irradiated at different linac powers.

Portable X-Ray Fluorescence Analysis of a CW Facility Site for Arsenic Containing Warfare Agents

Arsenic containing chemical warfare agents used in Germany during the second world war were destroyed at the end of the war. One consequence of this was the deposition of arsenic onto the soil. Arsenic contamination in soil is an environmental and human health problem. The extent and location of the arsenic contamination needed to be determined.