The Experts below are selected from a list of 13929 Experts worldwide ranked by ideXlab platform
Karl Wuhrmann - One of the best experts on this subject based on the ideXlab platform.
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The influence of the sulphonic group on the biodegradability of n-Alkylbenzene sulphonates.
Xenobiotica, 2008Co-Authors: H. Leidner, Rolf Gloor, D. Wüest, Karl WuhrmannAbstract:1. Model compounds of the type β-n-Alkylbenzene sulphonates, β-n-alkylbenzoic acids and phenylcarboxylic acids were tested for biodegradability. Bioassays were performed with unadapted mixed cultures (soil suspensions) using the Organization for Economic Cooperation and Development (OECD) screening test.2. Degradation was measured by dissolved organic carbon analysis and g.l.c. or h.p.l.c.3. β-n-Alkylbenzene sulphonates were resistant to microbial attack. The carboxylated compounds with analogous structures, however, with one exception, were easily decomposed.4. The results indicate that the persistent character of β-n-Alkylbenzene sulphonates is mainly due to the sulphonic substituent.
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The influence of the sulphonic group on the biodegradability of n-Alkylbenzene sulphonates.
Xenobiotica, 2008Co-Authors: H. Leidner, Rolf Gloor, D. Wüest, Karl WuhrmannAbstract:1. Model compounds of the type β-n-Alkylbenzene sulphonates, β-n-alkylbenzoic acids and phenylcarboxylic acids were tested for biodegradability. Bioassays were performed with unadapted mixed cultures (soil suspensions) using the Organization for Economic Cooperation and Development (OECD) screening test.2. Degradation was measured by dissolved organic carbon analysis and g.l.c. or h.p.l.c.3. β-n-Alkylbenzene sulphonates were resistant to microbial attack. The carboxylated compounds with analogous structures, however, with one exception, were easily decomposed.4. The results indicate that the persistent character of β-n-Alkylbenzene sulphonates is mainly due to the sulphonic substituent.
H. Leidner - One of the best experts on this subject based on the ideXlab platform.
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The influence of the sulphonic group on the biodegradability of n-Alkylbenzene sulphonates.
Xenobiotica, 2008Co-Authors: H. Leidner, Rolf Gloor, D. Wüest, Karl WuhrmannAbstract:1. Model compounds of the type β-n-Alkylbenzene sulphonates, β-n-alkylbenzoic acids and phenylcarboxylic acids were tested for biodegradability. Bioassays were performed with unadapted mixed cultures (soil suspensions) using the Organization for Economic Cooperation and Development (OECD) screening test.2. Degradation was measured by dissolved organic carbon analysis and g.l.c. or h.p.l.c.3. β-n-Alkylbenzene sulphonates were resistant to microbial attack. The carboxylated compounds with analogous structures, however, with one exception, were easily decomposed.4. The results indicate that the persistent character of β-n-Alkylbenzene sulphonates is mainly due to the sulphonic substituent.
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The influence of the sulphonic group on the biodegradability of n-Alkylbenzene sulphonates.
Xenobiotica, 2008Co-Authors: H. Leidner, Rolf Gloor, D. Wüest, Karl WuhrmannAbstract:1. Model compounds of the type β-n-Alkylbenzene sulphonates, β-n-alkylbenzoic acids and phenylcarboxylic acids were tested for biodegradability. Bioassays were performed with unadapted mixed cultures (soil suspensions) using the Organization for Economic Cooperation and Development (OECD) screening test.2. Degradation was measured by dissolved organic carbon analysis and g.l.c. or h.p.l.c.3. β-n-Alkylbenzene sulphonates were resistant to microbial attack. The carboxylated compounds with analogous structures, however, with one exception, were easily decomposed.4. The results indicate that the persistent character of β-n-Alkylbenzene sulphonates is mainly due to the sulphonic substituent.
Shuichang Zhang - One of the best experts on this subject based on the ideXlab platform.
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geochemistry of Alkylbenzenes in the paleozoic oils from the tarim basin nw china
Organic Geochemistry, 2014Co-Authors: Haiping Huang, Jin Su, Shuichang Zhang, Haifeng ZhangAbstract:a b s t r a c t Monoaromatic hydrocarbons (Alkylbenzenes) in Paleozoic oils/condensates from the Tarim Basin were quantitatively analyzed using gas chromatography–mass spectrometry. Their relative abundances and distributions show large variation, which are most likely controlled by the temperature and duration of the catagenesis stage of petroleum maturation. Relatively high abundance of long chain linear substituted Alkylbenzenes and alkyltoluenes in the studied samples implies that source rocks of these oils/ condensates contain high contents of algal material. The dominance of dodecylbenzene in these n-Alkylbenzenes suggests the formation of Alkylbenzenes from fatty acids via lactone formation (dehydration). The 1,2,3,4-tetramethylbenzene (TeMB), 1-methyl-3-phytanylbenzene (1-M-3-PyB) and aryl isoprenoids are mainly derived from carotenoids produced by Chlorobiaceae and their occurrence may indicate a highly reducing depositional environment. However, the concentration of these compounds diminishes significantly at high maturity. With increasing thermal maturity, the prominent trend of demethylation of Alkylbenzenes is accompanied by shortening of alkyl side chains. Large variation in the C4-Alkylbenzene isomer distribution is also controlled by thermal maturity. The 1,2,3,5-TeMB and 1,2,4,5-TeMB isomers are more stable than other TeMB isomers and the overall thermodynamic stability of TeMBs is lower than that of dimethylethylbenzenes. Therefore, several maturity parameters can be derived based on Alkylbenzene stability. Absolute concentrations of Alkylbenzenes generally increase with increasing thermal maturity, but concentrations of 1-M-3-PyB and aryl isoprenoids decrease significantly at high maturity. Maturity parameters obtained from Alkylbenzenes are especially useful for highly mature oils and condensates when most biomarkers are depleted. Caution is advised when interpreting the paleoenvironment and thermal maturity of an oil from the Alkylbenzene signatures because they are affected by various other processes such as evaporative fractionation, thermal cracking and biodegradation as well.
R. E. Smith - One of the best experts on this subject based on the ideXlab platform.
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Vapor-phase adsorption of Alkylbenzenes and water on soils and clays
Chemosphere, 2003Co-Authors: R.d. Rhue, R. E. SmithAbstract:Abstract Vapor-phase adsorption of water and three Alkylbenzenes (toluene, p-xylene, and ethylbenzene) on bentonite, kaolin, two soil samples, an aquifer material, and a silica gel was measured by a procedure in which vapor-phase concentrations were measured by trapping the vapors in methanol and adsorbed-phase concentrations were measured by methanol-extraction. Water in the methanol was measured by titration with Karl Fischer reagent; Alkylbenzenes were measured by UV spectrophotometry and/or HPLC analysis. Bentonite and the two soil samples adsorbed much more water than Alkylbenzene. Kaolin adsorbed nearly equal amounts of water and Alkylbenzene, while silica gel adsorbed nearly twice as much of the Alkylbenzenes as water. With the exception of water adsorption on bentonite and Alkylbenzene adsorption on Oldsmar soil (Alfic Arenic Haplaquod), adsorption conformed to type-II adsorption isotherms which were adequately described by the BET adsorption model. Surface areas calculated from BET monolayer capacities indicated that the surface available for Alkylbenzene adsorption was essentially that measured by N 2 adsorption except for silica gel. Values for the relative adsorption (the amount adsorbed divided by the monolayer capacity as determined by the BET model) of water and p-xylene were similar for several of the adsorbents used.
Hideshige Takada - One of the best experts on this subject based on the ideXlab platform.
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Alkylbenzenes in mussels from south and south east asian coasts as a molecular tool to assess sewage impact
Marine Pollution Bulletin, 2002Co-Authors: Shinobu Tsutsumi, Yuka Yamaguchi, Itsuko Nishida, Kenichiro Akiyama, Mohamad Pauzi Zakaria, Hideshige TakadaAbstract:Abstract Alkylbenzenes, molecular markers of sewage, were measured in 34 green mussels collected from India, Indonesia, Malaysia, Thailand, Cambodia, Vietnam, and the Philippines together with blue mussels collected from Tokyo Bay, Japan. Linear Alkylbenzene (LAB) concentrations in South and South East Asian countries ranged from 10 to 1640 ng-∑LAB/g-dry tissue. In some populous cities, LAB concentrations were similar or higher than those found in northern Tokyo Bay which is heavily impacted by sewage effluents. I / E ratios (a ratio of internal to external isomers of LABs) in the South and South East Asian countries (1–3) were much lower than those in Tokyo Bay (3–8), indicating sewage discharged in the coastal zone is poorly treated (e.g., raw sewage and/or primary effluents). Alkylbenzenes with branched alkyl chains, tetrapropylene-based Alkylbenzenes, were also detected in mussels from Indonesia and Philippines. This “tell-tale” sign indicates that poorly degradable detergents are still in use in this area, although they have long been phased-out in many industrialized countries.
