Monitoring volatile organic compounds in groundwater: indicators of organic hazardous wastes pollution in Missouri

This research addresses the role of volatile organic compounds (VOC) as indicators of groundwater pollution by hazardous wastes. These compounds consist primarily of hydrocarbons, e.g., benzene, and chlorinated hydrocarbons, e.g., trichloroethylene, that are neutral, only sparingly soluble in water, and readily evaporated from water. Because of their lack of chemical reactivity under mild conditions and their ready volatilization, VOC are particularly difficult to determine in groundwater, and emphasis has been placed on that aspect of the research. Chromatography, in some cases combined with mass spectrometry, has been used as the analytical method of choice. Attention has been given to sample preservation and consideration to the possibility of on-site monitoring.Project # G-1027-03 Agreement # 14-08-0001-G-1027-0

Application of Electron-Attachment Reactions to Enhance Selectivity of Electron-Capture Detector for Nitroaromatic Explosives

The differences in the extent of electron-attachment reactions between thermal electrons and selected classes of organic molecules with high electron affinities were investigated. the investigations showed that interactions of thermal electrons with nitroaromatic compounds lead to the formation of neutral products with very low electron affinities. by contrast, a number of other analytes with high electron affinities such as polyhalogenated organic compounds, lead to products with high electron affinities. This difference was exploited to differentiate between nitroaromatic and polychlorinated organic compounds with a tandem arrangement consisting of two electron-capture detectors connected in series with an electron-attachment reactor

Solvent and Method for Extraction of Triglyceride Rich Oil

The present invention relates to a solvent for use in extracting oil from an oil bearing material, such as soybeans, with the solvent resulting in the selective extraction of a triglyceride rich oil, which contains 95% or greater triglycerides and non-polar constituents, with the solvent comprised of a hydrocarbon, preferably hexane, and a fluorocarbon, so that the solvent has a viscosity less than 2.6 centipoise and a polarity of less than 0.1. The present invention also relates to a method of using the solvent to extract the triglyceride rich oil, with the method including preferably extracting the oil at a temperature ranging between 35° C. and 55° C., and then preferably cooling resulting miscella to a temperature ranging between 15° C. and 25° C

Solvent and Method for Extraction of Triglyceride Rich Oil

The present invention relates to a solvent for use in extracting oil from an oil bearing material, such as soybeans, with the solvent resulting in the selective extraction of a triglyceride rich oil, which contains 95% or greater triglycerides and non-polar constituents, with the solvent comprised of a hydrocarbon, preferably hexane, and a fluorocarbon, so that the solvent has a viscosity less than 2.6 centipoise and a polarity of less than 0.1. The present invention also relates to a method of using the solvent to extract the triglyceride rich oil, with the method including preferably extracting the oil at a temperature ranging between 35° C. and 55° C., and then preferably cooling resulting miscella to a temperature ranging between 15° C. and 25° C

Solvent and Method for Extraction of Triglyceride Rich Oil

The present invention relates to a solvent for use in extracting oil from an oil bearing material, such as soybeans, with the solvent resulting in the selective extraction of a triglyceride rich oil, which contains 95% or greater triglycerides and non-polar constituents, with the solvent comprised of a hydrocarbon, preferably hexane, and a fluorocarbon, so that the solvent has a viscosity less than 2.6 centipoise and a polarity of less than 0.1. The present invention also relates to a method of using the solvent to extract the triglyceride rich oil, with the method including preferably extracting the oil at a temperature ranging between 35° C. and 55° C., and then preferably cooling resulting miscella to a temperature ranging between 15° C. and 25° C

Disposition of polychlorinated dibenzo-p- dioxins from soils to the aquatic environment

The contamination of many sites in Missouri with 2, 3, 7, 8 tetrachlorodibenzo-p-dioxin (TCDD) is without doubt the single most publicized and pressing environmental issue in Missouri. This contamination is centered around the past improper disposal of waste from a hexachlorophene production facility at Verona, Missouri (1). Due to its extremely high toxicity to a number of mammals TCDD has drawn considerable attention and has been the focus of extensive research in many parts of the world (2-4). Large data bases for the compound in terms of toxicity and incidences of environmental contamination are available (5,6); however, certain important basic data are still required for realistic assessment of hazards posed by this compound in soil to human health and environment. Furthermore, there exists a need for fundamental environmental physiochemical studies directed towards gaining an understanding of the chemical processes and fates of TCDD and similar molecules in the environment.Project # G-916-04 Agreement # 14-08-0001-G-916-0

Regeneration of Spent Carbon by a Novel Oxidative Thermal Process

An oxidative thermal regeneration process was developed and evaluated for its potential applicability in several environmental areas. The feasibility of the process is affected strongly by the gradual carbon loss, energy consumption, physical changes of carbon, and effective destruction efficiency of adsorbed materials during the regeneration. The aim of the study is to determine the optimum conditions to maintain acceptable destruction efficiency for adsorbed organics, controlling oxidant flow rate. Prior to its applications, various preliminary tests were carried out to determine the effects of experimental parameters on the process. The tests performed were reaction temperature, carbon loss, surface area, surface structure, and adsorptive property. The results of these tests show that the parameters are dependent on oxidant flow rate, and suggest that the process is comparable and, in some ways, possibly superior to conventional regeneration techniques because the oxidative process is a single step and less energy intensive

Some Aspects of Organic Tin Analysis by Gas Chromatography-flame Photometry

The emissions of organic tin compounds in the small flame of a photometric detector was studied. Emissions were observed at the blue and red regions. The emission in the blue region was broad (e. g. , 360-490 nm) and was significantly influenced by the siliceous surfaces in the proximity of the flame. The emission in the red region was sharp (maximum at 610 nm) and was less affected by such surfaces. The relative usefulness of these emissions in the chromatographic analysis of organotin compounds is presented

Studies and Speculations on an Alternative Mechanism for the Response of Direct-current Electron-capture Detectors

The classical theory of electron-capture detection does not allow for hypercoulometric response such as has been found recently under conditions of elevated pressure in some electron-capture detectors (ECDs), nor does it predict certain other experimental observations. In an effort to understand why and how hypercoulometric performance can occur, measurements have been made of the ionization region and characteristic current-voltage relationships in real and simulated ECDs. The centre-of-ionization was found much closer to the foil than is commonly assumed, namely at approximately 1 mm for 63Ni and approximately 0.2 mm for 3H in nitrogen at ambient conditions. A hypothetical response mechanism, alternative and, in certain ways, complementary to the classical theory was therefore developed. It sees detector response, distinct from the initial electron-capture reaction, as the effect of a space charge formed by migrating negative ions, which decrease the field gradient (and therefore increase electron-positive ion recombination) in the ionization region. Estimates of the counterfield established by the migration of anions show that it can indeed produce hypercoulometric response and that, in agreement with experimental observations, increased pressure leads to higher response. Some simple experimental tests of the proposed mechanism have been carried out and others, more crucial ones, are suggested for future investigation. © 1980

FPD: Burner Configurations and the Response to Hetero-organics

Dependence of flame photometric detector response on burner design and other parameters, such as flow rates of H2, O2, air, and mode of mixing was investigated. These parameters affected the response of sulfur, phosphorus, and arsenic test compounds to a varying degree. Addition of helium to the flame caused an enhancement in sulfur and phosphorus response, and a 3-fold increase in S/N ratio was obtained. With optimized conditions, a minimum detectable limit of about 3 pg methyl parathion was obtained. Under suitable conditions good sensitivity and selectivity (over carbon) were observed for triphenyl arsine