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2007-4-10 Environ. Sci. & Technol. 最新文章及摘要
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1. [Journal Home Page] [Search the Journals] [Table of Contents] [PDF version of this article] [Download to Citation Manager] [Purchase Article] Environ. Sci. Technol., ASAP Article 10.1021/es062384k S0013-936X(06)02384-4 Web Release Date: April 10, 2007 Copyright © 2007 American Chemical Society Natural Production of Organic Bromine Compounds in Berlin Lakes Alexandra Hütteroth, Anke Putschew,* and Martin Jekel Technical University Berlin, Department of Water Quality Control, Sekr. KF4, Strasse des 17. Juni 135, 10623 Berlin, Germany Received for review October 5, 2006 Revised manuscript received February 27, 2007 Accepted March 9, 2007 Abstract: Berlin surface waters are characterized by elevated concentrations of organic bound bromine (up to 35 g/L) in late summer. Organic bromine compounds in lakes are of significant importance because human life is closely connected to fresh water. Apart from recreational use, fresh water is frequently used for the production of drinking water, e.g., after bank filtration. Therefore the source, particularly the mechanism responsible for the formation is studied. Field studies indicate that the organic bromine compounds, measured as adsorbable organic bromine (AOBr), are autochthonous. Staggered maxima concentrations of chlorophyll-a, DOC and AOBr indicate that phototrophic organisms might contribute to the AOBr after death. The involvement of phototrophic organisms was established in the laboratory using surface water and/or cultures of organisms. Light and the presence of phototrophic organisms are essential for an AOBr production. Phototrophic organisms incorporate bromide, which is released randomly and after cell death. A part of the incorporated bromide is used for the formation of organic bromine compounds in the cell. After death of the organisms the brominated compounds and the incorporated bromide are released into the water phase, and an extracellular AOBr production can lead to a further formation of AOBr, most probably due to the parallel release of haloperoxidases. -------------------------------------------------------------------------------- [Full text in html] [Full text in pdf] |
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2. [Journal Home Page] [Search the Journals] [Table of Contents] [PDF version of this article] [Download to Citation Manager] [Purchase Article] Environ. Sci. Technol., ASAP Article 10.1021/es062073+ S0013-936X(06)02073-6 Web Release Date: April 10, 2007 Copyright © 2007 American Chemical Society Selenomethionine Biotransformation and Incorporation into Proteins along a Simulated Terrestrial Food Chain Jason M. Unrine,* Brian P. Jackson, and William A. Hopkins Savannah River Ecology Laboratory, The University of Georgia, P.O. Drawer E, Aiken, South Carolina 29802, Departments of Chemistry and Earth Sciences, Dartmouth College, Hanover, New Hampshire, and Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia Received for review August 29, 2006 Revised manuscript received February 28, 2007 Accepted March 5, 2007 Abstract: Selenium is an essential trace element in vertebrates, but there is a narrow concentration range between dietary requirement and toxicity threshold. Although a great deal is known about the biochemistry of Se from a nutritional perspective, considerably less attention has been focused on the specific biochemistry of Se as an environmental toxicant. Recent advances in hyphenated analytical techniques have provided the capability of quantifying specific chemical forms of Se in biological tissues as well as the distribution of Se among macromolecules. We applied liquid chromatography coupled to inductively coupled plasma mass spectrometry to investigate biotransformations of selenomethionine along a simulated terrestrial food chain consisting of selenomethionine exposed crickets (Acheta domesticus) fed to western fence lizards (Sceloporus occidentalis). Evidence was obtained for selenomethionine biotransformation as well as for sex-specific differences in the metabolism of Se compounds and their subsequent incorporation into proteins in the lizard. The results demonstrate the complexities involved in trophic transfer of Se due to the potential for extensive biotransformation and the species- and even sex-specific nature of these biotransformations. -------------------------------------------------------------------------------- [Full text in html] [Full text in pdf] |
2楼2007-04-10 22:29:25
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3. [Journal Home Page] [Search the Journals] [Table of Contents] [PDF version of this article] [Download to Citation Manager] [Purchase Article] Environ. Sci. Technol., ASAP Article 10.1021/es0624422 S0013-936X(06)02442-4 Web Release Date: April 10, 2007 Copyright © 2007 American Chemical Society Reflectance Spectroscopy Study of Cd Contamination in the Sediments of the Changjiang River, China Xue Qi Xia,* Yu Qian Mao, Jun Feng Ji,* Hong Rui Ma, Jun Chen, and Qi Lin Liao State Key Laboratory of Mineral Deposit Research, Institute of Surficial Geochemistry, Department of Earth Sciences, Nanjing University, Nanjing 210093, China, and Geological Survey of Jiangsu Province, Nanjing 210093, China Received for review October 11, 2006 Revised manuscript received March 4, 2007 Accepted March 8, 2007 Abstract: Sediments of the Changjiang River have been found in recent studies to be enriched in cadmium (Cd). The possibility and mechanisms for evaluating total Cd concentration and its binding form using reflectance spectroscopy within the visible-near-infrared (VNIR) region (400-2500 nm) have been investigated. Bottom sediments (69 samples) in the lower reaches of the river were collected for chemical analyses and spectral measurements. Total Cd concentration in the sediments was found to be exponentially related to the spectral proxies for organic matter (spectral reflectance at 400-530 nm), clay minerals (first derivative (FD) values at the shoulders related to absorption bands near 1400, 1900, and 2200 nm), and Fe oxides (FD values at 560-760 nm). The results indicated that the spectrally featureless Cd was mostly bound to these spectrally active materials, which made it possible for Cd concentration to be determined from reflectance spectra. This conclusion was also confirmed by the results of chemically sequential extraction of Cd. This study has demonstrated the usage and theoretical basis of reflectance spectroscopy, which is a rapid and inexpensive analytical method, for evaluating contamination by heavy metals and their binding forms in sediments. -------------------------------------------------------------------------------- [Full text in html] [Full text in pdf] 4. [Journal Home Page] [Search the Journals] [Table of Contents] [PDF version of this article] [Download to Citation Manager] [Purchase Article] Environ. Sci. Technol., ASAP Article 10.1021/es062990f S0013-936X(06)02990-7 Web Release Date: April 10, 2007 Copyright © 2007 American Chemical Society Impact of Surface Water Conditions on Preservative Leaching and Aquatic Toxicity from Treated Wood Products Brajesh Dubey, Timothy Townsend,* Helena Solo-Gabriele, and Gabriel Bitton Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, Florida 32611-6450, and Departments of Civil, Architectural and Environmental Engineering, University of Miami, Coral Gables, Florida 33124-0630 Received for review December 17, 2006 Revised manuscript received March 8, 2007 Accepted March 12, 2007 Abstract: New alternative wood preservatives contain higher levels of copper (Cu) which can promote aquatic toxicity in natural water systems. Earlier work focused on evaluating toxicity using laboratory generated leaching solutions. In this study, the impact on preservative leaching and aquatic toxicity from treated wood products was evaluated using natural surface waters including waters from two rivers, three lakes, two wetlands, and one seawater, in addition to synthetic moderate hard water and deionized water. Blocks of wood treated with Cu based alternatives such as alkaline copper quaternary (ACQ) and copper boron azole (CBA), along with chromated copper arsenate (CCA)-treated wood, were leached under quiescent conditions, and total Cu, labile Cu, and heavy metal toxicity were measured. Results show that ACQ- and CBA-treated wood leach approximately 10 and 20 times more total Cu relative to CCA-treated wood and that the presence of organic and inorganic ligands in natural waters lowered the labile fraction of Cu relative to that from laboratory generated leaching solutions. Aquatic toxicity was found to correlate with the labile Cu fraction, and hence, the aquatic toxicity of the treated wood leachates was lower in natural waters in comparison to laboratory leaching solutions. The results of the present study suggest that studies designed to evaluate the impacts of treated wood should therefore consider the role of complexation in reducing the labile Cu fraction and its potential role in decreasing toxicity. -------------------------------------------------------------------------------- [Full text in html] [Full text in pdf] 5. [Journal Home Page] [Search the Journals] [Table of Contents] [PDF version of this article] [Download to Citation Manager] [Purchase Article] Environ. Sci. Technol., ASAP Article 10.1021/es062384k S0013-936X(06)02384-4 Web Release Date: April 10, 2007 Copyright © 2007 American Chemical Society Natural Production of Organic Bromine Compounds in Berlin Lakes Alexandra Hütteroth, Anke Putschew,* and Martin Jekel Technical University Berlin, Department of Water Quality Control, Sekr. KF4, Strasse des 17. Juni 135, 10623 Berlin, Germany Received for review October 5, 2006 Revised manuscript received February 27, 2007 Accepted March 9, 2007 Abstract: Berlin surface waters are characterized by elevated concentrations of organic bound bromine (up to 35 g/L) in late summer. Organic bromine compounds in lakes are of significant importance because human life is closely connected to fresh water. Apart from recreational use, fresh water is frequently used for the production of drinking water, e.g., after bank filtration. Therefore the source, particularly the mechanism responsible for the formation is studied. Field studies indicate that the organic bromine compounds, measured as adsorbable organic bromine (AOBr), are autochthonous. Staggered maxima concentrations of chlorophyll-a, DOC and AOBr indicate that phototrophic organisms might contribute to the AOBr after death. The involvement of phototrophic organisms was established in the laboratory using surface water and/or cultures of organisms. Light and the presence of phototrophic organisms are essential for an AOBr production. Phototrophic organisms incorporate bromide, which is released randomly and after cell death. A part of the incorporated bromide is used for the formation of organic bromine compounds in the cell. After death of the organisms the brominated compounds and the incorporated bromide are released into the water phase, and an extracellular AOBr production can lead to a further formation of AOBr, most probably due to the parallel release of haloperoxidases. -------------------------------------------------------------------------------- [Full text in html] [Full text in pdf] |
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