Kevin Thorn
Kevin Thorn is an Emeritus Research Chemist in the USGS Water Resources Mission Area.
I was a Research Chemist in the Water Mission Area from 1982 to 2019, and was the lead for the Carbon and Nitrogen Biogeochemistry project in the former National Research Program, specializing in the application of Nuclear Magnetic Resonance (NMR) spectroscopy to environmental and organic geochemistry. Research topics include the structure and reactivity of soil and aquatic humic substances and natural organic matter (NOM), the environmental chemistry and bioremediation of nitroaromatic munitions, including 2,4,6-trinitrotoluene (TNT), biodegradation of crude oil, the biogeochemical cycling of nitrogen in soil and water, and soil aquifer treatment of reclaimed water.
Education and Certifications
B.A., Chemistry and Biochemistry, Bowdoin College, Brunswick, Maine, 1978.
M.S., Agricultural Biochemistry and Nutrition, University of Arizona, Tucson, 1981.
Ph.D., Agricultural Biochemistry and Nutrition, University of Arizona, Tucson, 1984.
Science and Products
Filter Total Items: 33
Organic geochemistry and sources of natural aquatic foams
Aquatic foams and stream-water samples were collected from two pristine sites for humic substances isolation and characterization. Biomarker compounds identified in foam and stream humic substances included phospholipid fatty acids, steroids, and lignin. Results showed that foams had a 10 to 20 fold greater DOC concentration and were enriched in humic substances (90% by weight of DOC) that showed
Authors
M. S. Mills, E.M. Thurman, J. Ertel, Kevin A. Thorn
Ammonia fixation by humic substances: A nitrogen-15 and carbon-13 NMR study
The process of ammonia fixation has been studied in three well characterized and structurally diverse fulvic and humic acid samples. The Suwannee River fulvic acid, and the IHSS peat and leonardite humic acids, were reacted with 15N-labelled ammonium hydroxide, and analyzed by liquid phase 15N NMR spectrometry. Elemental analyses and liquid phase 13C NMR spectra also were recorded on the samples b
Authors
K. A. Thorn, M.A. Mikita
Identification of persistent anionic surfactant-derived chemicals in sewage effluent and groundwater
Preparative isolation and fractionation procedures coupled with spectrometric analyses were used to identify surfactant-derived contaminants in sewage effluent and sewage-contaminated groundwater from a site located on Cape Cod, Massachusetts. Anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsor
Authors
Jennifer A. Field, Jerry A. Leenheer, Kevin A. Thorn, Larry B. Barber, Colleen Rostad, Donald L. Macalady, Stephen R. Daniel
Nitrogen-15 and carbon-13 NMR investigation of hydroxylamine-derivatized humic substances
No abstract available.
Authors
Kevin A. Thorn, Jeffrey B. Arterburn, Michael A. Mikita
Characterization of the International Humic Substances Society standard and reference fulvic and humic acids by solution state carbon-13 (13C) and hydrogen-1 (1H) nuclear magnetic resonance spectrometry
Standard and reference samples of the International Humic Substances Society have been characterized by solution state carbon-13 and hydrogen-1 nuclear magnetic resonance (NMR) spectrometry. Samples included the Suwannee River, soil, and peat standard fulvic and humic acids, the Leonardite standard humic acid, the Nordic aquatic reference fulvic and humic acids, and the Summit Hill soil reference
Authors
Kevin A. Thorn, Daniel W. Folan, Patrick MacCarthy
Humic substances in the Suwannee River, Georgia; interactions, properties, and proposed structures
Humic substances as a collective term and humic and fulvic acids as specific terms are not household words. For about a century, these terms belonged to the domain of the soil scientist. Even^though their chemical structures remained elusive, they were recognized as important entities in soil. During the past decade or so, there has been a renewed interest in humic substances in soil and water. Su
Characterization of humic acid fractions by C-13 nuclear magnetic resonance spectroscopy
Soil humic acids from different environments were fractionated by adsorption chromatography on Sephadex and characterized by C‐13 nuclear magnetic resonance (NMR) spectroscopy. The C‐13 NMR spectra of the fractions consist of some sharp, well‐resolved lines and some broad bands in contrast to the spectra of the unfractionated humic acids, where the bands are broader and less well‐resolved. The mar
Authors
Robert L. Wershaw, Kevin A. Thorn, D. J. Pinckney
Determination of alkylbenzenesulfonate surfactants in groundwater using macroreticular resins and carbon-13 nuclear magnetic resonance spectrometry
Alkylbenzenesulfonate surfactants were determined in groundwater at concentrations as low as 0.3 mg/L. The method uses XAD-8 resin for concentration, followed by elution with methanol, separation of anionic and nonionic surfactants by anion exchange, quantitation by titration, and identification by 13C nuclear magnetic resonance spectrometry. Laboratory standards and field samples containing strai
Authors
E. Michael Thurman, T. Willoughby, Larry B. Barber, Kevin A. Thorn
**1**5N-NMR INVESTIGATION OF HYDROXYLAMINE DERIVATIZED HUMIC SUBSTANCES.
Humic substances are the most abundant naturally occurring refactory organic compounds in soils and water. They have a broad range of physical, chemical and physiological properties. In soils, humic substances contribute to the cation exchange capacity, help maintain the physical structure, and play a role in plant growth and nutrition. In aquatic systems, humic substances serve to regulate the le
Authors
Kevin A. Thorn, Jeffrey B. Arterburn, Michael A. Mikita
Science and Products
Filter Total Items: 33
Organic geochemistry and sources of natural aquatic foams
Aquatic foams and stream-water samples were collected from two pristine sites for humic substances isolation and characterization. Biomarker compounds identified in foam and stream humic substances included phospholipid fatty acids, steroids, and lignin. Results showed that foams had a 10 to 20 fold greater DOC concentration and were enriched in humic substances (90% by weight of DOC) that showed
Authors
M. S. Mills, E.M. Thurman, J. Ertel, Kevin A. Thorn
Ammonia fixation by humic substances: A nitrogen-15 and carbon-13 NMR study
The process of ammonia fixation has been studied in three well characterized and structurally diverse fulvic and humic acid samples. The Suwannee River fulvic acid, and the IHSS peat and leonardite humic acids, were reacted with 15N-labelled ammonium hydroxide, and analyzed by liquid phase 15N NMR spectrometry. Elemental analyses and liquid phase 13C NMR spectra also were recorded on the samples b
Authors
K. A. Thorn, M.A. Mikita
Identification of persistent anionic surfactant-derived chemicals in sewage effluent and groundwater
Preparative isolation and fractionation procedures coupled with spectrometric analyses were used to identify surfactant-derived contaminants in sewage effluent and sewage-contaminated groundwater from a site located on Cape Cod, Massachusetts. Anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsor
Authors
Jennifer A. Field, Jerry A. Leenheer, Kevin A. Thorn, Larry B. Barber, Colleen Rostad, Donald L. Macalady, Stephen R. Daniel
Nitrogen-15 and carbon-13 NMR investigation of hydroxylamine-derivatized humic substances
No abstract available.
Authors
Kevin A. Thorn, Jeffrey B. Arterburn, Michael A. Mikita
Characterization of the International Humic Substances Society standard and reference fulvic and humic acids by solution state carbon-13 (13C) and hydrogen-1 (1H) nuclear magnetic resonance spectrometry
Standard and reference samples of the International Humic Substances Society have been characterized by solution state carbon-13 and hydrogen-1 nuclear magnetic resonance (NMR) spectrometry. Samples included the Suwannee River, soil, and peat standard fulvic and humic acids, the Leonardite standard humic acid, the Nordic aquatic reference fulvic and humic acids, and the Summit Hill soil reference
Authors
Kevin A. Thorn, Daniel W. Folan, Patrick MacCarthy
Humic substances in the Suwannee River, Georgia; interactions, properties, and proposed structures
Humic substances as a collective term and humic and fulvic acids as specific terms are not household words. For about a century, these terms belonged to the domain of the soil scientist. Even^though their chemical structures remained elusive, they were recognized as important entities in soil. During the past decade or so, there has been a renewed interest in humic substances in soil and water. Su
Characterization of humic acid fractions by C-13 nuclear magnetic resonance spectroscopy
Soil humic acids from different environments were fractionated by adsorption chromatography on Sephadex and characterized by C‐13 nuclear magnetic resonance (NMR) spectroscopy. The C‐13 NMR spectra of the fractions consist of some sharp, well‐resolved lines and some broad bands in contrast to the spectra of the unfractionated humic acids, where the bands are broader and less well‐resolved. The mar
Authors
Robert L. Wershaw, Kevin A. Thorn, D. J. Pinckney
Determination of alkylbenzenesulfonate surfactants in groundwater using macroreticular resins and carbon-13 nuclear magnetic resonance spectrometry
Alkylbenzenesulfonate surfactants were determined in groundwater at concentrations as low as 0.3 mg/L. The method uses XAD-8 resin for concentration, followed by elution with methanol, separation of anionic and nonionic surfactants by anion exchange, quantitation by titration, and identification by 13C nuclear magnetic resonance spectrometry. Laboratory standards and field samples containing strai
Authors
E. Michael Thurman, T. Willoughby, Larry B. Barber, Kevin A. Thorn
**1**5N-NMR INVESTIGATION OF HYDROXYLAMINE DERIVATIZED HUMIC SUBSTANCES.
Humic substances are the most abundant naturally occurring refactory organic compounds in soils and water. They have a broad range of physical, chemical and physiological properties. In soils, humic substances contribute to the cation exchange capacity, help maintain the physical structure, and play a role in plant growth and nutrition. In aquatic systems, humic substances serve to regulate the le
Authors
Kevin A. Thorn, Jeffrey B. Arterburn, Michael A. Mikita