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Sample records for extractable organic halogens

  1. Optimization of dynamic headspace extraction system for measurement of halogenated volatile organic compounds in liquid or viscous samples

    Science.gov (United States)

    Taniai, G.; Oda, H.; Kurihara, M.; Hashimoto, S.

    2010-12-01

    Halogenated volatile organic compounds (HVOCs) produced in the marine environment are thought to play a key role in atmospheric reactions, particularly those involved in the global radiation budget and the depression of tropospheric and stratospheric ozone. To evaluate HVOCs concentrations in the various natural samples, we developed an automated dynamic headspace extraction method for the determination of 15 HVOCs, such as chloromethane, bromomethane, bromoethane, iodomethane, iodoethane, bromochloromethane, 1-iodopropane, 2-iodopropane, dibromomethane, bromodichloromethane, chloroiodomethane, chlorodibromomethane, bromoiodomethane, tribromomethane, and diiodomethane. Dynamic headspace system (GERSTEL DHS) was used to purge the gas phase above samples and to trap HVOCs on the adsorbent column from the purge gas. We measured the HVOCs concentrations in the adsorbent column with gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5975C). In dynamic headspace system, an glass tube containing Tenax TA or Tenax GR was used as adsorbent column for the collection of 15 HVOCs. The parameters for purge and trap extraction, such as purge flow rate (ml/min), purge volume (ml), incubation time (min), and agitator speed (rpm), were optimized. The detection limits of HVOCs in water samples were 1270 pM (chloromethane), 103 pM (bromomethane), 42.1 pM (iodomethane), and 1.4 to 10.2 pM (other HVOCs). The repeatability (relative standard deviation) for 15 HVOCs were < 9 % except chloromethane (16.2 %) and bromomethane (11.0 %). On the basis of the measurements for various samples, we concluded that this analytical method is useful for the determination of wide range of HVOCs with boiling points between - 24°C (chloromethane) and 181°C (diiodomethane) for the liquid or viscous samples.

  2. Halogen Bonding in Organic Synthesis and Organocatalysis.

    Science.gov (United States)

    Bulfield, David; Huber, Stefan M

    2016-10-01

    Halogen bonding is a noncovalent interaction similar to hydrogen bonding, which is based on electrophilic halogen substituents. Hydrogen-bonding-based organocatalysis is a well-established strategy which has found numerous applications in recent years. In light of this, halogen bonding has recently been introduced as a key interaction for the design of activators or organocatalysts that is complementary to hydrogen bonding. This Concept features a discussion on the history and electronic origin of halogen bonding, summarizes all relevant examples of its application in organocatalysis, and provides an overview on the use of cationic or polyfluorinated halogen-bond donors in halide abstraction reactions or in the activation of neutral organic substrates.

  3. Screening of organic halogens and identification of chlorinated benzoic acids in carbonaceous meteorites.

    Science.gov (United States)

    Schöler, Heinz F; Nkusi, Gerard; Niedan, Volker W; Müller, German; Spitthoff, Bianca

    2005-09-01

    The occurrence of halogenated organic compounds measured as a sum parameter and the evidence of chlorinated benzoic acids in four carbonaceous meteorites (Cold Bokkeveld, Murray, Murchison and Orgueil) from four independent fall events is reported. After AOX (Adsorbable organic halogen) and EOX (Extractable organic halogen) screening to quantify organically bound halogens, chlorinated organic compounds were analyzed by gas chromatography. AOX concentrations varying from 124 to 209 microg Cl/g d.w. were observed in carbonaceous meteorites. Ion chromatographic analysis of the distribution of organically bound halogens performed on the Cold Bokkeveld meteorite revealed that chlorinated and brominated organic compounds were extractable, up to 70%, whereas only trace amounts of organofluorines could be extracted. Chlorinated benzoic acids have been identified in carbonaceous meteorite extracts. Their presence and concentrations raise the question concerning the origin of halogenated, especially chlorinated, organic compounds in primitive planetary matter.

  4. Organic halogens in spruce forest throughfall

    DEFF Research Database (Denmark)

    Öberg, G.; Johansen, C.; Grøn, C.

    1998-01-01

    . No relationship between the position of the collectors and the forest edge or dominating wind-direction was found, suggesting that dry deposition was not a major source. The concentration of organic halogens was related to that of organic carbon and decreased from the tree-trunk and outwards. In addition......Deposition of dissolved organic halogens by throughfall was determined in a small spruce forest site in Denmark (56 degrees 28'N, 8 degrees 24'E). The mean annual deposition of dissolved organic halogens was 377 g ha(-1)yr(-1), and larger than the general deposition by precipitation......, the concentrations were higher during the growing season than during the dormant season. This indicates that the major part of the organic carbon and organic halogens in spruce forest throughfall originates from canopy leachates or other internal sources. (C) 1998 Elsevier Science Ltd....

  5. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

    2002-06-01

    Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

  6. Selective pressurized liquid extraction technique for halogenated organic pollutants in marine mammal blubber: a lipid-rich matrix.

    Science.gov (United States)

    Robinson, E M; Jia, M; Trumble, S J; Usenko, S

    2015-03-13

    Analytical methods for unique and rare samples, such as marine mammal tissue, strive to reduce opportunities for analyte loss and contamination. Historically, analytical methodologies for marine mammal tissues required an extraction followed by multiple cleanup and concentration steps. These steps increase the opportunity for analyte loss and sample contamination. Selective pressurized liquid extractions (SPLE; an analytical technique that combines PLE with in-cell adsorbent cleanup) have the potential to reduce and/or eliminate the number of steps. A SPLE method was developed for the simultaneous extraction of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) from bowhead whale blubber. This SPLE utilized acidic silica with a fat-to-fat retainer ratio of 0.02 as well as eliminated post-extraction cleanup steps, such as size-exclusion chromatography step. In addition, neutral silica was placed beneath the acidic silica as an acid buffer, thereby preventing acid from contaminating the extraction system. Analysis was performed using gas chromatography/mass spectrometry in electron capture negative ionization mode. PBDE, PCB and OCP triplicate recoveries averaged 84±1%, 83±3%, and 76±11%, respectively. Overall, measurements of NIST Whale Blubber SRM 1945 were within±30% of certified values. PBDEs were measured for the first time in bowhead whale blubber; average concentrations ranged from 0.2 to 1.4 ng g(-1) wet weight (ww). Average OCPs and PCBs concentrations ranged from 0.4 to 37 ng g(-1)ww and 0.1 to 3.0 ng g(-1)ww, respectively, which were within one order of magnitude lower than those previously reported in bowhead whale blubber.

  7. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

    2003-07-01

    Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward

  8. Halogenation processes of secondary organic aerosol and implications on halogen release mechanisms

    Directory of Open Access Journals (Sweden)

    J. Ofner

    2012-07-01

    Full Text Available Reactive halogen species (RHS, such as X·, X2 and HOX containing X = chlorine and/or bromine, are released by various sources like photo-activated sea-salt aerosol or from salt pans, and salt lakes. Despite many studies of RHS reactions, the potential of RHS reacting with secondary organic aerosol (SOA and organic aerosol derived from biomass-burning (BBOA has been neglected. Such reactions can constitute sources of gaseous organohalogen compounds or halogenated organic matter in the tropospheric boundary layer and can influence physicochemical properties of atmospheric aerosols.

    Model SOA from α-pinene, catechol, and guaiacol was used to study heterogeneous interactions with RHS. Particles were exposed to molecular chlorine and bromine in an aerosol smog-chamber in the presence of UV/VIS irradiation and to RHS, released from simulated natural halogen sources like salt pans. Subsequently, the aerosol was characterized in detail using a variety of physicochemical and spectroscopic methods. Fundamental features were correlated with heterogeneous halogenation, which results in new functional groups (FTIR spectroscopy, changes UV/VIS absorption, chemical composition (ultrahigh resolution mass spectroscopy (ICR-FT/MS, or aerosol size distribution. However, the halogen release mechanisms were also found to be affected by the presence of organic aerosol. Those interaction processes, changing chemical and physical properties of the aerosol are likely to influence e.g. the ability of the aerosol to act as cloud condensation nuclei, its potential to adsorb other gases with low-volatility, or its contribution to radiative forcing and ultimately the Earth's radiation balance.

  9. Characterization of halogenated DBPs and identification of new DBPs trihalomethanols in chlorine dioxide treated drinking water with multiple extractions.

    Science.gov (United States)

    Han, Jiarui; Zhang, Xiangru; Liu, Jiaqi; Zhu, Xiaohu; Gong, Tingting

    2017-08-01

    Chlorine dioxide (ClO2) is a widely used alternative disinfectant due to its high biocidal efficiency and low-level formation of trihalomethanes and haloacetic acids. A major portion of total organic halogen (TOX), a collective parameter for all halogenated DBPs, formed in ClO2-treated drinking water is still unknown. A commonly used pretreatment method for analyzing halogenated DBPs in drinking water is one-time liquid-liquid extraction (LLE), which may lead to a substantial loss of DBPs prior to analysis. In this study, characterization and identification of polar halogenated DBPs in a ClO2-treated drinking water sample were conducted by pretreating the sample with multiple extractions. Compared to one-time LLE, the combined four-time LLEs improved the recovery of TOX by 2.3 times. The developmental toxicity of the drinking water sample pretreated with the combined four-time LLEs was 1.67 times higher than that pretreated with one-time LLE. With the aid of ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, a new group of polar halogenated DBPs, trihalomethanols, were detected in the drinking water sample pretreated with multiple extractions; two of them, trichloromethanol and bromodichloromethanol, were identified with synthesized standard compounds. Moreover, these trihalomethanols were found to be the transformation products of trihalomethanes formed during ClO2 disinfection. The results indicate that multiple LLEs can significantly improve extraction efficiencies of polar halogenated DBPs and is a better pretreatment method for characterizing and identifying new polar halogenated DBPs in drinking water. Copyright © 2017. Published by Elsevier B.V.

  10. Halogen bonding: A new retention mechanism for the solid phase extraction of perfluorinated iodoalkanes

    Energy Technology Data Exchange (ETDEWEB)

    Yan Xiaoqing; Shen Qianjin; Zhao Xiaoran; Gao Haiyue; Pang Xue [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Jin Weijun, E-mail: wjjin@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2012-11-13

    Highlights: Black-Right-Pointing-Pointer Halogen bonding (XB) is firstly utilised in solid phase extraction. Black-Right-Pointing-Pointer The perfluorinated iodine alkanes can be extracted by C-I Midline-Horizontal-Ellipsis Cl{sup -} halogen bonding. Black-Right-Pointing-Pointer The C-I Midline-Horizontal-Ellipsis Cl{sup -} halogen bond is well characterised by spectroscopy methods. Black-Right-Pointing-Pointer The analytes with strong halogen-bonding abilities can be selectively extracted. - Abstract: For the first time, halogen-bonding interaction is utilised in the solid phase extraction of perfluorinated iodoalkane (PFI). Nine PFIs, as model analytes, were tested, and analyses by UV, {sup 19}F NMR and Raman spectroscopies demonstrate that the PFIs are extracted by a strong anion exchange (SAX) sorbent from n-hexane due to the C-I Midline-Horizontal-Ellipsis Cl{sup -} halogen-bonding interactions. The results also show that the adsorptivities of SAX for the diiodoperfluoro-alkanes (diiodo-PFIs) were much stronger than those for the perfluoroalkyl iodides (monoiodo-PFIs). Specifically, the recoveries for 1,6-diiodoperfluorohexane and 1,8-diiodoperfluorooctane were higher than 80% when 100 mL of sample spiked with a 5 ng mL{sup -1} analyte mixture was extracted. Interestingly, SAX had no adsorption for hexafluorobenzene at all, which is known to be unable to form a halogen bond with Cl{sup -}. The analytical performance of the halogen bond-based SPE-GC-MS method for the diiodo-PFIs was also examined in soil samples. The sorbent SAX enabled the selective extraction of four diiodo-PFIs successfully from soil samples. The recoveries of the diiodo-PFIs extracted from 5 g soil sample at the 100 ng g{sup -1} spike level were in the range of 73.2-93.8% except 26.8% for 1,2-diiodoperfluoroethane. The limit of detection varied from 0.02 to 0.04 ng g{sup -1} in soil samples. Overall, this work reveals the great application potential of halogen bonding in the field of solid

  11. 40 CFR Appendix III to Part 268 - List of Halogenated Organic Compounds Regulated Under § 268.32

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false List of Halogenated Organic Compounds... Part 268—List of Halogenated Organic Compounds Regulated Under § 268.32 In determining the... defined the HOCs that must be included in a calculation as any compounds having a carbon-halogen...

  12. Alternative sorptive extraction method for gas chromatography determination of halogenated anisoles in water and wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)], E-mail: qnisaac@usc.es; Rubi, E.; Bollain, M.H.; Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2007-09-05

    An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 h and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 {mu}L. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L{sup -1}, depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated.

  13. Rational design of organic semiconductors for texture control and self-patterning on halogenated surfaces

    KAUST Repository

    Ward, Jeremy W.

    2014-05-15

    Understanding the interactions at interfaces between the materials constituting consecutive layers within organic thin-film transistors (OTFTs) is vital for optimizing charge injection and transport, tuning thin-film microstructure, and designing new materials. Here, the influence of the interactions at the interface between a halogenated organic semiconductor (OSC) thin film and a halogenated self-assembled monolayer on the formation of the crystalline texture directly affecting the performance of OTFTs is explored. By correlating the results from microbeam grazing incidence wide angle X-ray scattering (μGIWAXS) measurements of structure and texture with OTFT characteristics, two or more interaction paths between the terminating atoms of the semiconductor and the halogenated surface are found to be vital to templating a highly ordered morphology in the first layer. These interactions are effective when the separating distance is lower than 2.5 dw, where dw represents the van der Waals distance. The ability to modulate charge carrier transport by several orders of magnitude by promoting "edge-on" versus "face-on" molecular orientation and crystallographic textures in OSCs is demonstrated. It is found that the "edge-on" self-assembly of molecules forms uniform, (001) lamellar-textured crystallites which promote high charge carrier mobility, and that charge transport suffers as the fraction of the "face-on" oriented crystallites increases. The role of interfacial halogenation in mediating texture formation and the self-patterning of organic semiconductor films, as well as the resulting effects on charge transport in organic thin-film transistors, are explored. The presence of two or more anchoring sites between a halogenated semiconductor and a halogenated self-assembled monolayer, closer than about twice the corresponding van der Waals distance, alter the microstructure and improve electrical properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera

    Energy Technology Data Exchange (ETDEWEB)

    Grimalt, Joan O.; Carrizo, Daniel; Otero, Raquel; Vizcaino, Esther [Institute of Environmental Assessment and Water Research (IDAeA-CSIC), Department of Environmental Chemistry, Barcelona, Catalonia (Spain); Howsam, Mike [Universite de Lille 2, Centre Universitaire de Mesure et d' Analyse, Faculte de Pharmacie, Lille (France); Rodrigues de Marchi, Mary Rosa [Institute of Chemistry UNESP, Department of Analytical Chemistry, Araraquara, SP (Brazil)

    2010-03-15

    A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000{mu}L were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes ({>=}300 {mu}L) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n=73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described. (orig.)

  15. Halogenated methanesulfonic acids: A new class of organic micropollutants in the water cycle.

    Science.gov (United States)

    Zahn, Daniel; Frömel, Tobias; Knepper, Thomas P

    2016-09-15

    Mobile and persistent organic micropollutants may impact raw and drinking waters and are thus of concern for human health. To identify such possible substances of concern nineteen water samples from five European countries (France, Switzerland, The Netherlands, Spain and Germany) and different compartments of the water cycle (urban effluent, surface water, ground water and drinking water) were enriched with mixed-mode solid phase extraction. Hydrophilic interaction liquid chromatography - high resolution mass spectrometry non-target screening of these samples led to the detection and structural elucidation of seven novel organic micropollutants. One structure could already be confirmed by a reference standard (trifluoromethanesulfonic acid) and six were tentatively identified based on experimental evidence (chloromethanesulfonic acid, dichloromethanesulfonic acid, trichloromethanesulfonic acid, bromomethanesulfonic acid, dibromomethanesulfonic acid and bromochloromethanesulfonic acid). Approximated concentrations for these substances show that trifluoromethanesulfonic acid, a chemical registered under the European Union regulation REACH with a production volume of more than 100 t/a, is able to spread along the water cycle and may be present in concentrations up to the μg/L range. Chlorinated and brominated methanesulfonic acids were predominantly detected together which indicates a common source and first experimental evidence points towards water disinfection as a potential origin. Halogenated methanesulfonic acids were detected in drinking waters and thus may be new substances of concern.

  16. Large area inkjet printing for organic photovoltaics and organic light emitting diodes using non-halogenated ink formulations

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; Coenen, M.J.J.; Slaats, M.W.L.; Groen, W.A.

    2014-01-01

    The transfer of laboratory scale solution processing of organic electronics to large area roll-to-roll production requires the use of up-scalable deposition techniques. Furthermore, industrial production demands the omission of halogenated and other harmful solvents. Here, the authors discuss large

  17. Large area inkjet printing for organic photovoltaics and organic light emitting diodes using non-halogenated ink formulations

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; Coenen, M.J.J.; Slaats, M.W.L.; Groen, W.A.

    2014-01-01

    The transfer of laboratory scale solution processing of organic electronics to large area roll-to-roll production requires the use of up-scalable deposition techniques. Furthermore, industrial production demands the omission of halogenated and other harmful solvents. Here, the authors discuss large

  18. Halogenated organic species over the tropical South American rainforest

    Directory of Open Access Journals (Sweden)

    S. Gebhardt

    2008-06-01

    Full Text Available Airborne measurements of the halogenated trace gases methyl chloride, methyl bromide and chloroform were conducted over the Atlantic Ocean and about 1000 km of pristine tropical rainforest in Suriname and French Guyana (3–6° N, 51–59° W in October 2005. In the boundary layer (0–1.4 km, maritime air masses, advected over the forest by southeasterly trade winds, were measured at various distances from the coast. Since the organohalogens presented here have relatively long atmospheric lifetimes (0.4–1.0 years in comparison to the advection times from the coast (1–2 days, emissions will accumulate in air traversing the rainforest. The distributions of methyl chloride, methyl bromide and chloroform were analyzed as a function of time the air spent over land and the respective relationship used to determine net fluxes from the rainforest for one week within the long dry season.

    Net fluxes from the rainforest ecosystem have been calculated for methyl chloride and chloroform as 9.5 (±3.8 2σ and 0.35 (±0.15 2σμg m-2 h−1, respectively. No significant flux was observed for methyl bromide within the limits of these measurements.

    The global budget of methyl chloride contains large uncertainties, in particular with regard to a possible source from tropical vegetation. Our measurements are used in a large-scale approach to determine the net flux from a tropical ecosystem to the planetary boundary layer. The obtained global net flux of 1.5 (±0.6 2σ Tg yr-1 for methyl chloride is at the lower end of current estimates for tropical vegetation sources, which helps to constrain the range of tropical sources and sinks (0.82 to 8.2 Tg yr-1 from tropical plants, 0.03 to 2.5 Tg yr-1 from senescent/dead leaves and a sink of 0.1 to 1.6 Tg yr-1 by soil uptake. Nevertheless, these results show that the contribution of the rainforest ecosystem is the major source in the

  19. Organic halogenated contaminants in mother-fetus pairs of harbor seals (Phoca vitulina richardii) from Alaska, 2000-2002

    Science.gov (United States)

    Environmental stressors may interfere with foraging, survival and reproduction of marine mammals resulting in marine mammal population decline. In this study, organic halogenated pollutants [OHs, including organochlorine pesticides, polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCN...

  20. Halogens in pore water of peat bogs – the role of peat decomposition and dissolved organic matter

    Directory of Open Access Journals (Sweden)

    H. Biester

    2006-01-01

    Full Text Available Halogens are strongly enriched in peat and peatlands and such they are one of their largest active terrestrial reservoir. The enrichment of halogens in peat is mainly attributed to the formation of organohalogens and climatically controlled humification processes. However, little is known about release of halogens from the peat substrate and the distribution of halogens in the peat pore water. In this study we have investigated the distribution of chlorine, bromine and iodine in pore water of three pristine peat bogs located in the Magellanic Moorlands, southern Chile. Peat pore waters were collected using a sipping technique, which allows in situ sampling down to a depth greater than 6m. Halogens and halogen species in pore water were determined by ion-chromatography (IC (chlorine and IC-ICP-MS (bromine and iodine. Results show that halogen concentrations in pore water are 15–30 times higher than in rainwater. Mean concentrations of chlorine, bromine and iodine in pore water were 7–15 mg l−1, 56–123 μg l−1, and 10–20 μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organobromine and organoiodine were the predominant species in pore waters, whereas chlorine in pore water was mostly chloride. Advection and diffusion of halogens were found to be generally low and halogen concentrations appear to reflect release from the peat substrate. Release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC was also the most intensive. It has been concluded that the release of halogenated dissolved organic matter (DOM is the predominant mechanism of iodine and bromine release from peat.

  1. Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

    Directory of Open Access Journals (Sweden)

    P. B. Shepson

    2008-03-01

    Full Text Available Volatile organic compound concentration ratios can be used as indicators of halogen chemistry that occurs during ozone depletion events in the Arctic during spring. Here we use a combination of modeling and measurements of [acetone]/[propanal] as an indicator of bromine chemistry, and [isobutane]/[n-butane] and [methyl ethyl ketone]/[n-butane] are used to study the extent of chlorine chemistry during four ozone depletion events during the Polar Sunrise Experiment of 1995. Using a 0-D photochemistry model in which the input of halogen atoms is controlled and varied, the approximate ratio of [Br]/[Cl] can be estimated for each ozone depletion event. It is concluded that there must be an additional source of propanal (likely from the snowpack to correctly simulate the VOC chemistry of the Arctic, and further evidence that the ratio of Br atoms to Cl atoms can vary greatly during ozone depletion events is presented.

  2. Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

    Directory of Open Access Journals (Sweden)

    A. E. Cavender

    2007-08-01

    Full Text Available Volatile organic compound concentration ratios can be used as indicators of halogen chemistry that occurs during ozone depletion events in the Arctic during spring. Here we use a combination of modeling and measurements of [acetone]/[propanal] as an indicator of bromine chemistry, and [isobutane]/[n-butane] and [methyl ethyl ketone]/[n-butane] are used to study the extent of chlorine chemistry during four ozone depletion events during the Polar Sunrise Experiment of 1995. Using a 0-D photochemistry model in which the input of halogen atoms is controlled and varied, the approximate ratio of [Br]/[Cl] can be estimated for each ozone depletion event. It is concluded that there must be an additional source of propanal (likely from the snowpack to correctly simulate the VOC chemistry of the Arctic, and that the ratio of Br atoms to Cl atoms can vary greatly during ozone depletion events.

  3. Nucleophilic reactivity and electrocatalytic reduction of halogenated organic compounds by nickel o-phenylenedioxamidate complexes.

    Science.gov (United States)

    Das, Siva Prasad; Ganguly, Rakesh; Li, Yongxin; Soo, Han Sen

    2016-09-14

    A growing number of halogenated organic compounds have been identified as hazardous pollutants. Although numerous advanced oxidative processes have been developed to degrade organohalide compounds, reductive and nucleophilic molecular approaches to dehalogenate organic compounds have rarely been reported. In this manuscript, we employ nickel(ii)-ate complexes bearing the o-phenylenebis(N-methyloxamide) (Me2opba) tetraanionic ligand as nucleophilic reagents that can react with alkyl halides (methyl up to the bulky isobutyl) by O-alkylation to give their respective imidate products. Four new nickel(ii) complexes have been characterized by X-ray crystallography, and the salient structural parameters and FT-IR vibrational bands (∼1655 cm(-1)) concur with their assignment as the imidate tautomeric form. To the best of our knowledge, this is the first report on the nucleophilic reactivity of Ni(II)(Me2opba) with halogenated organic compounds. The parent nickel(ii) Me2opba complex exhibits reversible electrochemical oxidation and reduction behavior. As a proof of concept, Ni(II)(Me2opba) and its alkylated congeners were utilized for the electrocatalytic reduction of chloroform, as a representative, simple polyhalogenated organic molecule that could arise from the oxidative treatment of organic compounds by chlorination. Modest turnover numbers of up to 6 were recorded, with dichloromethane identified as one of the possible products. Future efforts are directed towards bulkier -ate complexes that possess metal-centered instead of ligand-centered nucleophilic activity to create more effective electrocatalysts for the reduction of halogenated organic compounds.

  4. Halogen-induced organic aerosol (XOA) formation and decarboxylation of carboxylic acids by reactive halogen species - a time-resolved aerosol flow-reactor study

    Science.gov (United States)

    Ofner, Johannes; Zetzsch, Cornelius

    2013-04-01

    Reactive halogen species (RHS) are released to the atmosphere from various sources like photo-activated sea-salt aerosol and salt lakes. Recent studies (Cai et al., 2006 and 2008, Ofner et al., 2012) indicate that RHS are able to interact with SOA precursors similarly to common atmospheric oxidizing gases like OH radicals and ozone. The reaction of RHS with SOA precursors like terpenes forms so-called halogen-induced organic aerosol (XOA). On the other hand, RHS are also able to change the composition of functional groups, e.g. to initiate the decarboxylation of carboxylic acids (Ofner et al., 2012). The present study uses a 50 cm aerosol flow-reactor, equipped with a solar simulator to investigate the time-resolved evolution and transformation of vibrational features in the mid-infrared region. The aerosol flow-reactor is coupled to a home-made multi-reflection cell (Ofner et al., 2010), integrated into a Bruker IFS 113v FTIR spectrometer. The reactor is operated with an inlet feed (organic compound) and a surrounding feed (reactive halogen species). The moveable inlet of the flow reactor allows us to vary reaction times between a few seconds and up to about 3 minutes. Saturated vapours of different SOA precursors and carboxylic acids were fed into the flow reactor using the moveable inlet. The surrounding feed inside the flow reactor was a mixture of zero air with molecular chlorine as the precursor for the formation of reactive halogen species. Using this setup, the formation of halogen-induced organic aerosol could be monitored with a high time resolution using FTIR spectroscopy. XOA formation is characterized by hydrogen-atom abstraction, carbon-chlorine bond formation and later, even formation of carboxylic acids. Several changes of the entire structure of the organic precursor, caused by the reaction of RHS, are visible. While XOA formation is a very fast process, the decarboxylation of carboxylic acids, induced by RHS is rather slow. However, XOA formation

  5. Determination of gaseous semi-and low-volatile organic halogen compounds by barrier-discharge atomic emission spectrometry

    Institute of Scientific and Technical Information of China (English)

    Yifei Sun; Nobuhisa Watanabe; Wei Wang; Tianle Zhu

    2013-01-01

    A group parameter approach using "total organic halogen" is effective for monitoring gaseous organic halogen compounds,including fluorine,chlorine,and bromine compounds,generated from combustion.We described the use of barrier-discharge radiofrequencyhelium-plasma/atomic emission spectrometry,for the detection of semi-and low-volatile organic halogen compounds (SLVOXs),which can be collected by CarbotrapTM adsorbents and analyzed using thermal desorption.The optimal carrier gas flow rates at the injection and desorption lines were established to be 100 mL/min.The detection range for SLVOXs in the gaseous samples was from 10 ng to tens of micrograms.Measuring F was more diflicult than measuring Cl or Br,because the wavelength ofF is dose to that of air.The barrierdischarge radiofrequency-helium-plasma/atomic emission spectrometry measured from 85% to 103% of the SLVOXs in the gas sample.It has been found that Carbotrap B is appropriate for high-boiling-point compounds,and Carbotrap C is suitable for the determination of organic halogen compounds with lower boiling points,in the range 200-230℃.Under optimal analysis conditions,a chlorinecontaining plastic was destroyed using different oxygen concentrations.Lower oxygen concentrations resulted in the production of lower amounts of organic halogen compounds.

  6. Identifying bioaccumulative halogenated organic compounds using a nontargeted analytical approach: seabirds as sentinels.

    Directory of Open Access Journals (Sweden)

    Christopher J Millow

    Full Text Available Persistent organic pollutants (POPs are typically monitored via targeted mass spectrometry, which potentially identifies only a fraction of the contaminants actually present in environmental samples. With new anthropogenic compounds continuously introduced to the environment, novel and proactive approaches that provide a comprehensive alternative to targeted methods are needed in order to more completely characterize the diversity of known and unknown compounds likely to cause adverse effects. Nontargeted mass spectrometry attempts to extensively screen for compounds, providing a feasible approach for identifying contaminants that warrant future monitoring. We employed a nontargeted analytical method using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS to characterize halogenated organic compounds (HOCs in California Black skimmer (Rynchops niger eggs. Our study identified 111 HOCs; 84 of these compounds were regularly detected via targeted approaches, while 27 were classified as typically unmonitored or unknown. Typically unmonitored compounds of note in bird eggs included tris(4-chlorophenylmethane (TCPM, tris(4-chlorophenylmethanol (TCPMOH, triclosan, permethrin, heptachloro-1'-methyl-1,2'-bipyrrole (MBP, as well as four halogenated unknown compounds that could not be identified through database searching or the literature. The presence of these compounds in Black skimmer eggs suggests they are persistent, bioaccumulative, potentially biomagnifying, and maternally transferring. Our results highlight the utility and importance of employing nontargeted analytical tools to assess true contaminant burdens in organisms, as well as to demonstrate the value in using environmental sentinels to proactively identify novel contaminants.

  7. Brønsted Acidic Ionic Liquid Accelerated Halogenation of Organic Compounds with N-Halosuccinimides (NXS

    Directory of Open Access Journals (Sweden)

    Stojan Stavber

    2012-12-01

    Full Text Available The Brønsted-acidic ionic liquid 1-methyl-3-(4-sulfobutylimidazolium triflate [BMIM(SO3H][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS under mild conditions with short reaction times. Methyl aryl ketones were converted into α-halo and α,α-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures of α-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO3H][OTf] ionic liquid (IL-A was successfully reused eight times in a representative monohalogenation reaction with no noticeable decrease in efficiency. An effective halogenation scale-up in this IL is also presented. The reactivity trend and the observed chemo- and regioselectiivities point to an ET process in these IL-promoted halofunctionalization reactions.

  8. Brønsted acidic ionic liquid accelerated halogenation of organic compounds with N-Halosuccinimides (NXS).

    Science.gov (United States)

    Vražič, Dejan; Jereb, Marjan; Laali, Kenneth K; Stavber, Stojan

    2012-12-21

    The Brønsted-acidic ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium triflate [BMIM(SO(3)H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into α-halo and α,α-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures of α-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO(3)H)][OTf] ionic liquid (IL-A) was successfully reused eight times in a representative monohalogenation reaction with no noticeable decrease in efficiency. An effective halogenation scale-up in this IL is also presented. The reactivity trend and the observed chemo- and regioselectiivities point to an ET process in these IL-promoted halofunctionalization reactions.

  9. Halogen Chemistry in the CMAQ Model

    Science.gov (United States)

    Halogens (iodine and bromine) emitted from oceans alter atmospheric chemistry and influence atmospheric ozone mixing ratio. We previously incorporated a representation of detailed halogen chemistry and emissions of organic and inorganic halogen species into the hemispheric Commun...

  10. NanoSIMS50 - a powerful tool to elucidate cellular localization of halogenated organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gutleb, Arno C.; Hoffmann, Lucien [Centre de Recherche Public - Gabriel Lippmann, Department Environment and Agro-biotechnologies (EVA), Belvaux (Luxembourg); Freitas, Jaime [Wageningen University, Toxicology Section, Wageningen (Netherlands); Murk, Albertinka J. [Wageningen University, Toxicology Section, Wageningen (Netherlands); Wageningen IMARES, P.O. Box 68, IJmuiden (Netherlands); Verhaegen, Steven; Ropstad, Erik [Norwegian School of Veterinary Science, Oslo (Norway); Udelhoven, Thomas [Centre de Recherche Public - Gabriel Lippmann, Department Environment and Agro-biotechnologies (EVA), Belvaux (Luxembourg); Trier University, Remote Sensing and Geoinformatics Department, Trier (Germany); Audinot, Jean-Nicolas [Centre de Recherche Public - Gabriel Lippmann, Departement Science et Analyse des Materiaux (SAM), Belvaux (Luxembourg)

    2012-11-15

    Persistent organic pollutants are widely distributed in the environment and lots of toxicological data are available. However, little is known on the intracellular fate of such compounds. Here a method applying secondary ion mass spectrometry is described that can be used to visualize cellular localization of halogenated compounds and to semi-quantitatively calculate concentrations of such compounds. Of the model compounds tested, TBBPA was homogenously distributed in the cell membrane of the H295R cells while PFOS accumulated in very distinct locations in the cell membrane. Relative intracellular concentrations of 4-OH-BDE69 and 4-OH-BDE121 in GH3.TRE were 61 % and 18 %, respectively, compared to the parent compounds. These differences may partly explain that observed effect concentrations for 4-OH-BDEs in in vitro experiments are usually lower than what would be expected based on receptor binding studies. NanoSIMS50 proved to be a powerful tool to describe the cellular distribution of halogenated compounds. The semi-quantitative data that can be obtained may help to further explain results from in vitro or in vivo experiments. (orig.)

  11. Radiocarbon content of synthetic and natural semi-volatile halogenated organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, C.M.; Xu Li; Eglinton, T.I.; Boon, J.P.; Faulkner, D.J

    2002-12-01

    New developments in molecular-level {sup 14}C analysis techniques enable clues about natural versus commercial synthesis of trace organic contaminants. - Some halogenated organic compounds, such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polybrominated diphenyl ethers (PBDEs), have been suggested to have natural sources but separating these compounds from their commercially synthesized counterparts is difficult. Molecular-level {sup 14}C analysis may be beneficial since most synthetic compounds are manufactured from petrochemicals ({sup 14}C-free) and natural compounds should have 'modern' or 'contemporary' {sup 14}C levels. As a baseline study, we measured, for the first time, the {sup 14}C abundance in commercial PCB and PBDE mixtures, a number of organochlorine pesticides, as well as one natural product 2-(3', 5'-dibromo-2'-methoxyphenoxy)-3,5-dibromoanisole. The latter compound was isolated from a marine sponge and is similar in structure to a PBDE. All of the synthetic compounds were {sup 14}C-free except for the pesticide toxaphene, which had a modern {sup 14}C abundance, as did the brominated natural compound. The result for toxaphene was not surprising since it was commercially synthesized by the chlorination of camphene derived from pine trees. These results suggest that measuring the {sup 14}C content of halogenated organic compounds may be quite useful in establishing whether organic compounds encountered in the environment have natural or synthetic origins (or both) provided that any synthetic counterparts derive from petrochemical feedstock.

  12. Strong and Selective Halide Anion Binding by Neutral Halogen-Bonding [2]Rotaxanes in Wet Organic Solvents.

    Science.gov (United States)

    Lim, Jason Y C; Bunchuay, Thanthapatra; Beer, Paul D

    2017-04-03

    The design and construction of neutral interlocked host molecules for anion recognition are rare. Using an active-metal template approach, the preparation of a family of neutral halogen bonding (XB) rotaxanes containing two, three and four iodotriazole groups integrated into the macrocycle and axle components is achieved. In spite of the interlocked hosts' neutrality, such rotaxane systems are capable of binding halide anions strongly and selectively in wet organic solvent mixtures. Importantly, halide-binding strength and selectivity can be modulated by varying the number and position of the halogen bond donor iodotriazole groups within the interlocked cavity; the rotaxane containing the largest number of halogen bond donor groups exhibits the highest halide anion-binding affinities. By varying the percentage of water content in the solvent, neutral XB donor-mediated anion-binding strength is also demonstrated to be highly sensitive to solvent polarity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Headspace GC-MS Analysis of Halogenated Volatile Organic Compounds in Aqueous Samples: An Experiment for General Chemistry Laboratory

    Science.gov (United States)

    Keller, John W.; Fabbri, Cindy E.

    2012-01-01

    Analysis of halogenated volatile organic compounds (HVOCs) by GC-MS demonstrates the use of instrumentation in the environmental analysis of pollutant molecules and enhances student understanding of stable isotopes in nature. In this experiment, students separated and identified several HVOCs that have been implicated as industrial groundwater…

  14. Interactions between volatile organic compounds and reactive halogen in the tropical marine atmosphere using WRF-Chem

    Science.gov (United States)

    Badia, Alba; Reeves, Claire E.; Baker, Alex; Volkamer, Rainer; von Glasow, Roland

    2016-04-01

    Halogen species (chlorine, bromine and iodine) are known to play an important role in the chemistry and oxidizing capacity of the troposphere, particularly in the marine boundary layer (MBL). Reactive halogens cause ozone (O3) destruction, change the HOx and NOX partitioning, affect the oxidation of volatile organic compounds (VOCs) and mercury, reduce the lifetime of methane, and take part in new particle formation. Numerical models predicted that reactive halogen compounds account for 30% of O3 destruction in the MBL and 5-20% globally. There are indications that the chemistry of reactive halogens and oxygenated VOCs (OVOCs) in the tropics are inter-related. Moreover, the presence of aldehydes, such as glyoxal (CHOCHO), has a potential impact on radical cycling and secondary organic aerosol (SOA) formation in the MBL and free troposphere (FT). Model calculations suggest aldehydes to be an important sink for bromine atoms and hence competition for their reaction with O3 forming BrO and so illustrating a link between the cycles of halogens and OVOCs in the marine atmosphere. The main objective of this contribution is to investigate the atmospheric chemistry in the tropical East Pacific with a focus on reactive halogens and OVOCs and their links using the latest version of the Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem) and field data from the TORERO campaign. WRF-Chem is a highly flexible community model for atmospheric research where aerosol-radiation-cloud feedback processes are taken into account. Our current reaction mechanism in WRF-Chem is based on the MOZART mechanism and has been extended to include bromine, chlorine and iodine chemistry. The MOZART mechanism includes detailed gas-phase chemistry of CHOCHO formation as well as state-of-the-science pathways to form SOA. Oceanic emissions of aldehydes, including CHOCHO, and of organic halogens based on measurements from the TORERO campaign have been added into the model. Sea

  15. Impact of bromide on halogen incorporation into organic moieties in chlorinated drinking water treatment and distribution systems.

    Science.gov (United States)

    Tan, J; Allard, S; Gruchlik, Y; McDonald, S; Joll, C A; Heitz, A

    2016-01-15

    The impact of elevated bromide concentrations (399 to 750 μg/L) on the formation of halogenated disinfection by-products (DBPs), namely trihalomethanes, haloacetic acids, haloacetonitriles, and adsorbable organic halogen (AOX), in two drinking water systems was investigated. Bromine was the main halogen incorporated into all of the DBP classes and into organic carbon, even though chlorine was present in large excess to maintain a disinfectant residual. Due to the higher reactivity of bromine compared to chlorine, brominated DBPs were rapidly formed, followed by a slower increase in chlorinated DBPs. Higher bromine substitution and incorporation factors for individual DBP classes were observed for the chlorinated water from the groundwater source (lower concentration of dissolved organic carbon (DOC)), which contained a higher concentration of bromide, than for the surface water source (higher DOC). The molar distribution of adsorbable organic bromine to chlorine (AOBr/AOCl) for AOX in the groundwater distribution system was 1.5:1 and almost 1:1 for the surface water system. The measured (regulated) DBPs only accounted for 16 to 33% of the total organic halogen, demonstrating that AOX measurements are essential to provide a full understanding of the formation of halogenated DBPs in drinking waters. In addition, the study demonstrated that a significant proportion (up to 94%) of the bromide in source waters can be converted AOBr. An evaluation of AOBr and AOCl through a second groundwater treatment plant that uses conventional treatment processes for DOC removal produced 70% of AOX as AOBr, with 69% of the initial source water bromide converted to AOBr. Exposure to organobromine compounds is suspected to result in greater adverse health consequences than their chlorinated analogues. Therefore, this study highlights the need for improved methods to selectively reduce the bromide content in source waters.

  16. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS: THE NEW X-WAND HVOC SCREENING DEVICE

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Susan S. Sorini; Joseph F. Rovani Jr

    2006-03-01

    Western Research Institute (WRI) has developed new methodology and a test kit to screen soil or water samples for halogenated volatile organic compounds (HVOCs) in the field. The technology has been designated the X-Wand{trademark} screening tool. The new device uses a heated diode sensor that is commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. This sensor is selective to halogens. It does not respond to volatile aromatic hydrocarbons, such as those in gasoline, and it is not affected by high humidity. In the current work, the heated diode leak detectors were modified further to provide units with rapid response and enhanced sensitivity. The limit of detection for trichloroethylene TCE in air is 0.1 mg/m{sup 3} (S/N = 2). The response to other HVOCS relative to TCE is similar. Variability between sensors and changes in a particular sensor over time can be compensated for by normalizing sensor readings to a maximum sensor reading at 1,000 mg/m{sup 3} TCE. The soil TCE screening method was expanded to include application to water samples. Assuming complete vaporization, the detection limit for TCE in soil is about 1 ug/kg (ppb) for a 25-g sample in an 8-oz jar. The detection limit for TCE in water is about 1 ug/L (ppb) for a 25-mL sample in an 8-oz jar. This is comparable to quantitation limits of EPA GC/MS laboratory methods. A draft ASTM method for screening TCE contaminated soils using a heated diode sensor was successfully submitted for concurrent main committee and subcommittee balloting in ASTM Committee D 34 on Waste Management. The method was approved as ASTM D 7203-05, Standard Test Method for Screening Trichloroethylene (TCE)-Contaminated Soil Using a Heated Diode Sensor.

  17. Toxicity of gaseous halogenated organic compounds. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning the toxicology of halogenated hydrocarbons and their health effects. Topics cover halogenated gases used as industrial chemicals, fire extinguishers, anesthetics, solvents, pesticides, and aerosol propellants. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  18. Determination of volatile halogenated organic compounds in the tropical terrestrial ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, A.; Lopez-Garriga, J. [Univ. of Puerto Rico, Mayaguez (Puerto Rico)

    1995-12-01

    Volatile Halogenated Organic Compounds are discharged into our biosphere by plants, marine organisms, fungi and by other natural processes. Due to the high rate of evaporation of the tropical terrestrial ecosystem, the production of VHOC by fungi, higher plants and other organisms may be one of the most important sources of the total amount of VHOC released to the atmosphere from biogenic origin. The main goal of this research was to determine the VHOC`s released to the surroundings from biogenic origin in the tropical terrestrial ecosystem. Using vacuum distillation with cryogenic trapping and a thermal desorption unit coupled to a GC-ECD, we found that samples of air, water and soil contains 36.418 ng/L, 0.222 ng/mL and 9.156 ng/g (wet) of chloroform. Microorganisms such as the Actinomycetes and Halobacterium salinarium were also analyzed for VHOC`S contents. Carbontetrachloride, 1,1-dichloroethene, dichlorodifluoromethane, trichlorofluoromethane and other VHOC`S of environmental importance were determined. This is the first time that the presence of VHOC`S is reported in pure cultured bacteria.

  19. Brønsted Acidic Ionic Liquid Accelerated Halogenation of Organic Compounds with N-Halosuccinimides (NXS)

    National Research Council Canada - National Science Library

    Stojan Stavber; Kenneth K. Laali; Dejan Vražič; Marjan Jereb

    2012-01-01

    ...;-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO3H)][OTf] ionic liquid (IL...

  20. Brønsted acidic ionic liquid accelerated halogenation of organic compounds with N-Halosuccinimides (NXS)

    National Research Council Canada - National Science Library

    Vražič, Dejan; Jereb, Marjan; Laali, Kenneth K; Stavber, Stojan

    2012-01-01

    ...-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO(3)H)][OTf] ionic liquid (IL...

  1. Formation of halogenated organic byproducts during medium-pressure UV and chlorine coexposure of model compounds, NOM and bromide.

    Science.gov (United States)

    Zhao, Quan; Shang, Chii; Zhang, Xiangru; Ding, Guoyu; Yang, Xin

    2011-12-01

    When chlorine is applied before or during UV disinfection of bromide-containing water, interactions between chlorine, bromide and UV light are inevitable. Formation of halogenated organic byproducts was studied during medium-pressure UV (MPUV) and chlorine coexposure of phenol, nitrobenzene and benzoic acid and maleic acid, chosen to represent electron-donating aromatics, electron-withdrawing aromatics, and aliphatic structures in natural organic matter (NOM), respectively. All were evaluated in the presence and absence of bromide. MPUV and chlorine coexposure of phenol produced less total organic halogen (TOX, a collective parameter for halogenated organic byproducts) than chlorination in the dark, and more haloacetic acids instead of halophenols. Increases in TOX were found in the coexposure of nitrobenzene and benzoic acid, but maleic acid was rather inert during coexposure. The presence of bromide increased the formation of brominated TOX but did not significantly affect total TOX formation, in spite of the fact that it reduced hydroxyl radical levels. MPUV and chlorine coexposure of NOM gave a higher differential UV absorbance of NOM and a larger shift to lower molecular weight compounds than chlorination in the dark. However, TOX formation with NOM remained similar to that observed from dark chlorination.

  2. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume IV ? gas phase reactions of organic halogen species

    OpenAIRE

    2007-01-01

    International audience; This article, the fourth in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of organic halogen species, which were last published in 1997, and were updated on the IUPAC website in 2006. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and four appen...

  3. A Base-Resistant Metalloporphyrin Metal–Organic Framework for C–H Bond Halogenation

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xiu-Liang [Beijing Univ. of Technology (China). College of Environmental and Energy Engineering, Beijing Key Lab. for Green Catalysis and Separation, and Dept. of Chemistry and Chemical Engineering; Wang, Kecheng [Texas A& M Univ., College Station, TX (United States). Dept. of Chemistry; Wang, Bin [Beijing Univ. of Technology (China). College of Environmental and Energy Engineering, Beijing Key Lab. for Green Catalysis and Separation, and Dept. of Chemistry and Chemical Engineering; Su, Jie [Stockholm Univ. (Sweden). Berzelii Centre EXSELENT on Porous Materials and Inorganic and Structural Chemistry, Dept. of Materials and; Zou, Xiaodong [Stockholm Univ. (Sweden). Berzelii Centre EXSELENT on Porous Materials and Inorganic and Structural Chemistry, Dept. of Materials and Environmental Chemistry; Xie, Yabo [Beijing Univ. of Technology (China). College of Environmental and Energy Engineering, Beijing Key Lab. for Green Catalysis and Separation, and Dept. of Chemistry and Chemical Engineering; Li, Jian-Rong [Beijing Univ. of Technology (China). College of Environmental and Energy Engineering, Beijing Key Lab. for Green Catalysis and Separation, and Dept. of Chemistry and Chemical Engineering; Zhou, Hong-Cai [Texas A& M Univ., College Station, TX (United States). Dept. of Chemistry

    2017-01-11

    A base-resistant porphyrin metal–organic framework (MOF), namely PCN-602 has been constructed with 12-connected [Ni8(OH)4(H2O)2Pz12] (Pz = pyrazolate) cluster and a newly designed pyrazolate-based porphyrin ligand, 5,10,15,20-tetrakis(4-(pyrazolate-4-yl)phenyl)porphyrin under the guidance of the reticular synthesis strategy. Besides its robustness in hydroxide solution, PCN-602 also shows excellent stability in aqueous solutions of F, CO32–, and PO43– ions. Interestingly, the Mn3+-porphyrinic PCN-602, as a recyclable MOF catalyst, presents high catalytic activity for the C–H bond halogenation reaction in a basic system, significantly outperforming its homogeneous counterpart. For the first time, a porphyrinic MOF was thus used as an efficient catalyst in a basic solution with coordinating anions, to the best of our knowledge.

  4. Environmental health sciences center task force review on halogenated organics in drinking water.

    Science.gov (United States)

    Deinzer, M; Schaumburg, F; Klein, E

    1978-06-01

    The disinfection of drinking water by chlorination has in recent years come under closer scrutiny because of the potential hazards associated with the production of stable chlorinated organic chemicals. Organic chemical contaminants are common to all water supplies and it is now well-established that chlorinated by-products are obtained under conditions of disinfection, or during tertiary treatment of sewage whose products can ultimately find their way into drinking water supplies. Naturally occurring humic substances which are invariably present in drinking waters are probably the source of chloroform and other halogenated methanes, and chloroform has shown up in every water supply investigated thus far.The Environmental Protection Agency is charged with the responsibility of assessing the public health effects resulting from the consumption of contaminated drinking water. It has specifically undertaken the task of determining whether organic contaminants or their chlorinated derivatives have a special impact, and if so, what alternatives there are to protect the consumer against bacterial and viral diseases that are transmitted through infected drinking waters. The impetus to look at these chemicals is not entirely without some prima facie evidence of potential trouble. Epidemiological studies suggested a higher incidence of cancer along the lower Mississippi River where the contamination from organic chemicals is particularly high. The conclusions from these studies have, to be sure, not gone unchallenged.The task of assessing the effects of chemicals in the drinking water is a difficult one. It includes many variables, including differences in water supplies and the temporal relationship between contamination and consumption of the finished product. It must also take into account the relative importance of the effects from these chemicals in comparison to those from occupational exposure, ingestion of contaminated foods, inhalation of polluted air, and many

  5. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation...... and separation method. This review covers separation by solid phase chromatography, gel permeation chromatography, and liquid-liquid extraction, followed by halogen determination. All studies performed according to this outline have indicated that the major organohalogen compounds are chlorinated fatty acids...... bound in different lipids. For the detection and identification of individual, halogenated fatty acid methyl esters (FAMEs) liberated from the lipids, gas chromatography (GC) has been employed together with detection methods such as electron capture detection, electrolytic conductivity detection (ELCD...

  6. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume IV – gas phase reactions of organic halogen species

    Directory of Open Access Journals (Sweden)

    R. Atkinson

    2008-08-01

    Full Text Available This article, the fourth in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of organic halogen species, which were last published in 1997, and were updated on the IUPAC website in 2006/07. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and four appendices containing the data sheets, which provide information upon which the recommendations are made.

  7. Halogens in the atmosphere

    Science.gov (United States)

    Cicerone, R. J.

    1981-01-01

    Atmospheric halogen measurement data are presented for: (1) inorganic and organic gaseous compounds of chlorine, fluorine, bromine and iodine; and (2) chloride, fluoride, bromide and iodine in particulate form and in precipitation. The roles that these data and other, unavailable data play in the determination of the global cycles of the halogens are discussed. It is found that the speciation of the halogen gases in the troposphere is uncertain, with the only inorganic species detected by species-specific methods being HC1 and SF6. It is shown that heterogeneous reactions, both gas-to-particle and particle-to-gas processes, precipitation removal, and sea-salt aerosol generation and fractionation processes, need quantitative investigation to allow progress in estimating halogen sources and sinks. Where practical, quantitative comparisons are made between measured and predicted concentrations.

  8. Halogens in the atmosphere

    Science.gov (United States)

    Cicerone, R. J.

    1981-01-01

    Atmospheric halogen measurement data are presented for: (1) inorganic and organic gaseous compounds of chlorine, fluorine, bromine and iodine; and (2) chloride, fluoride, bromide and iodine in particulate form and in precipitation. The roles that these data and other, unavailable data play in the determination of the global cycles of the halogens are discussed. It is found that the speciation of the halogen gases in the troposphere is uncertain, with the only inorganic species detected by species-specific methods being HC1 and SF6. It is shown that heterogeneous reactions, both gas-to-particle and particle-to-gas processes, precipitation removal, and sea-salt aerosol generation and fractionation processes, need quantitative investigation to allow progress in estimating halogen sources and sinks. Where practical, quantitative comparisons are made between measured and predicted concentrations.

  9. Mutagenicity and organic halogen determination in body fluids and tissues of rats treated with drinking water and pulp mill bleachery effluent concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Monarca, S.; Hongslo, J.K.; Kringstad, A.; Carlberg, G.E.

    1984-01-01

    Concentrates of either drinking water or chlorination stage pulp mill effluent were injected intraperitonally into rats. Urine, feces, liver, and adipose tissues were treated for mutagenic activity and analysed for organic halogen. For both sample types nearly all the organic halogen taken up, eighteen percent from the chlorination stage sample and four percent from the drinking water sample, was excreted via the urine during the first day. Weak mutagenic activity could only be found in the urine collected the first day from animals treated with the highest dose of drinking water. 31 references, 5 tables.

  10. Persistent halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis) from the Canadian Arctic.

    Science.gov (United States)

    Braune, Birgit M; Mallory, Mark L; Butt, Craig M; Mabury, Scott A; Muir, Derek C G

    2010-12-01

    Northern fulmars from two breeding colonies in the Canadian Arctic, Cape Vera and Prince Leopold Island, were analyzed for organochlorine pesticides, PCBs, perfluorinated compounds (PFCs) and total mercury (Hg). Hepatic concentrations of organochlorines and Hg were highest in the male fulmars from Cape Vera. Perfluorooctane sulfonate (PFOS) concentrations did not vary significantly between sexes or colonies. However, concentrations of the perfluorinated carboxylates (PFCAs) were higher in fulmars from Cape Vera than Prince Leopold Island. The C(11)-C(15) PFCAs averaged 90% of the PFCA profile at both colonies. Polychorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs (NO-PCBs) were measured only in birds from Prince Leopold Island. Concentrations of PCDDs, PCDFs, NO-PCBs and Toxic Equivalents (TEQs) did not differ significantly between sexes. ΣTEQ was comprised mainly of ΣTEQ(PCDF). Concentrations of Hg and the persistent halogenated compounds reported in this study were below published toxicological threshold values for wild birds.

  11. Removal of halogenated organic compounds in landfill gas by top covers containing zero-valent iron

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Winther, K.; Kjeldsen, Peter

    2000-01-01

    Transformation of gaseous CCl3F and CCl4 by zero-valent iron was studied in systems unsaturated with water under anaerobic conditionssin an N2 gas and in a landfill gas atmosphere. The transformation was studied in batch as well as flow-through column tests. In both systems, the transformation...... process of the compounds was pseudo-firstorder. Transformation rate constants, referring to the water phase and normalized to 1 m2 iron surface/mL, of up to 1100 mL m-2 h-1 (batch) and 200 mL m-2 h-1 (flowthrough) were found. The transformation was strongly dependent on pH and the presence of oxygen....... During continuous aerobic conditions, the transformation of CCl3F decreased toward zero. Model calculations show that use of zero-valent iron in landfill top covers is a potential treatment technology for emission reduction of halogenated trace compounds from landfills....

  12. Tunable crossover between one- and three-dimensional magnetic dynamics in C oII single-chain magnets organized by halogen bonding

    Science.gov (United States)

    Amjad, A.; Clemente-Juan, J. M.; Coronado, E.; Luis, F.; Evangelisti, M.; Espallargas, G. Mínguez; del Barco, E.

    2016-06-01

    Low-temperature magnetometry, ac susceptibility, and calorimetry have been employed to study Co-based single-chain magnets (SCMs) organized through halogen bonding. Magnetic hysteresis and maxima in the dc and ac susceptibilities, respectively, confirm the SCM behavior of the system. Several characteristic magnetic relaxation regimes are observed at different temperatures, which can be associated with both intra- and interchain exchange interactions. Remarkably, tweaking the rate at which an external magnetic field is swept along the axis of the chains enables a controlled transition between the one- and three-dimensional dynamics. Experiments on an isostructural Co-based SCM system crystallized with different halogens do not show three-dimensional dynamics, illustrating the importance of halogen bonding on the control of interchain interactions.

  13. Occurrence of halogenated alkaloids.

    Science.gov (United States)

    Gribble, Gordon W

    2012-01-01

    blubber. Given the fact that of the 500,000 estimated marine organisms--which are the source of most halogenated alkaloids--only a small percentage have been investigated for their chemical content, it is certain that myriad new halogenated alkaloids are awaiting discovery. For example, it is estimated that nearly 4000 species of bryozoans have not been examined for their chemical content. The few species that have been studied contain some extraordinary halogenated alkaloids, such as hinckdentine A (610) and the chartellines (611-613). Of the estimated 1.5 million species of fungi, secondary metabolites have been characterized from only 5000 species. The future seems bright for the collector of halogenated alkaloids!

  14. Persistent halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis) from the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Braune, Birgit M., E-mail: birgit.braune@ec.gc.c [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, K1A 0H3 (Canada); Mallory, Mark L. [Environment Canada, Box 1714, Iqaluit, Nunavut, X0A 0H0 (Canada); Butt, Craig M.; Mabury, Scott A. [Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6 (Canada); Muir, Derek C.G. [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6 (Canada)

    2010-12-15

    Northern fulmars from two breeding colonies in the Canadian Arctic, Cape Vera and Prince Leopold Island, were analyzed for organochlorine pesticides, PCBs, perfluorinated compounds (PFCs) and total mercury (Hg). Hepatic concentrations of organochlorines and Hg were highest in the male fulmars from Cape Vera. Perfluorooctane sulfonate (PFOS) concentrations did not vary significantly between sexes or colonies. However, concentrations of the perfluorinated carboxylates (PFCAs) were higher in fulmars from Cape Vera than Prince Leopold Island. The C{sub 11}-C{sub 15} PFCAs averaged 90% of the PFCA profile at both colonies. Polychorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs (NO-PCBs) were measured only in birds from Prince Leopold Island. Concentrations of PCDDs, PCDFs, NO-PCBs and Toxic Equivalents (TEQs) did not differ significantly between sexes. {Sigma}TEQ was comprised mainly of {Sigma}TEQ{sub PCDF}. Concentrations of Hg and the persistent halogenated compounds reported in this study were below published toxicological threshold values for wild birds. - Northern fulmars in the Canadian Arctic demonstrate sex-specific, colony-specific, and regional differences in contaminant profiles.

  15. Release of Reactive Halogen Species from Sea-Salt Aerosols under Tropospheric Conditions with/without the Influence of Organic Matter in Smog-Chamber Experiments

    Science.gov (United States)

    Balzer, N.; Behnke, W.; Bleicher, S.; Krueger, H.; Ofner, J.; Siekmann, F.; Zetzsch, C.

    2008-12-01

    Experiments to investigate the release of reactive halogen species from sea-salt aerosol and the influence of organic matter were performed in an aerosol smog-chamber (3500 l), made of Teflon film (FEP 200A, Dupont). Smog chamber facilities at lowered temperature (coolable down to -25°C) enable us to simulate these reactions under polar, tropospheric conditions. First experiments were performed to investigate the production of atomic Br and Cl without the impact of organic aerosol. Br and Cl play an important role in atmospheric ozone depletion, particularly regarding ozone depletion events (bromine explosion) during polar spring. In these studies, the aerosol was generated by atomizing salt solutions containing the typical Br/Cl ratio of 1/660 in seawater by an ultrasonic nebulizer and increasing the Br content up to sixfold. To ensure the aqueous surface of the aerosol, the experiments were performed at relative humidities above 76%. We determined the atomic Cl and OH-radical concentrations from the simultaneous consumption of four reference hydrocarbons. The Br-radical concentration was calculated on the basis of ozone depletion. Organic aerosol may take part in these reaction cycles by halogenation and production of volatile organic halogens. Further experiments are planned to add organic aerosol for mechanistic and kinetic studies on the influence of secondary organic aerosols (SOA) and humic-like substances (HULIS) on bromine explosion. The formation of the secondary organic aerosol and the determination of possible halogenated gaseous and solid organic products will be studied using longpath-FTIR, DRIFTS, ATR-FTIR, GC-FID, GC-ECD, GC-MS, TPD-MS and DMA-CNC.

  16. Polycyclic aromatic hydrocarbons and halogenated persistent organic pollutants in canned fish and seafood products: smoked versus non-smoked products.

    Science.gov (United States)

    Drabova, Lucie; Pulkrabova, Jana; Kalachova, Kamila; Tomaniova, Monika; Kocourek, Vladimir; Hajslova, Jana

    2013-01-01

    In this study, levels of several groups of environmental contaminants represented by PAHs, PCBs, organochlorine pesticides and polybrominated diphenyl ethers were determined in various types of canned smoked and non-smoked fish and seafood products (54 samples) obtained from the Czech market. PAHs were detected in all of the studied samples, and at least one of the target halogenated persistent organic pollutants was present above the LOQ in 85% of the samples. The levels of PAHs, PCBs, organochlorine pesticides (mainly DDTs) and polybrominated diphenyl ethers found in the canned products varied in the range of 1.4-116 µg kg(-1), 0.6-59.6 µg kg(-1), 0.6-82.7 µg kg(-1) and 0.1-2.1 µg kg(-1) can content, respectively. Smoked sprats were the most contaminated fish product (n = 12) in which the highest levels of both PAHs and persistent organic pollutants were found. In 67% of the samples of smoked sprats in oil, the level of benzo[a]pyrene exceeded the maximum level of 5 µg kg(-1) established for smoked fish by European Union legislation. The distribution of target analytes between oil and fish fractions was also assessed. Significantly higher levels of PAHs were measured in the oil fraction.

  17. Biodegradation of Trihalomethanes and Other Halogenated Aliphatic Compounds

    Science.gov (United States)

    Smith, G. B.

    1996-01-01

    The biological dehalogenation of common water pollutants such as trichloromethane (chloroform) and other halogenated aliphatic compounds was the subject of this project. Samples from diverse water environments such as from groundwater contaminated with halogenated compounds and wastewaters from regional treatment plants were studied to identify conditions that favor certain dehalogenation reactions over others. Gene probe analyses of DNA extracted from the dichlormethane-degrading wastewater indicated the presence of the gene coding for dichloromethane dehalogenase, indicating the genetic basis for the dechlorination activity observed. These studies indicate that methanogenic bacteria are the organisms responsible for the chloroform dechlorination. Dechlorination of a common chlorofluorocarbon (CFC-11) was identified in samples taken from a regional aquifer contaminated with halogenated aliphatic compounds.

  18. Non-target screening of extractable and non-extractable organic xenobiotics in riverine sediments of Ems and Mulde Rivers, Germany.

    Science.gov (United States)

    Kronimus, Alexander; Schwarzbauer, Jan

    2007-05-01

    Subaquatic sediment samples derived form Elbe and Mulde Rivers, Germany, were analyzed for extractable and non-extractable anthropogenic organic compounds by a non-target screening approach. Applied methodologies were gas chromatography-mass spectrometry, dispersion extraction and degradation procedures, particularly alkaline and acidic hydrolysis, boron tribromide treatment, ruthenium tetroxide oxidation as well as pyrolysis and TMAH (tetramethylammonium hydroxide)-thermochemolysis. Numerous compounds were identified, including halogenated benzenes, anisoles, styrenes, alkanes, diphenylmethane derivates, anilines, phenols and diphenyl ethers. The results were interpreted with respect to compound specific modes of incorporation as well as to potential sources (e.g. municipal, agricultural, industrial). Extractable and non-extractable fractions differed significantly with respect to their qualitative and quantitative composition. For example, quantities in the extractable and non-extractable fractions of chlorinated benzenes differed up to factor 50. Among other significant results, the investigation revealed hints for a dependence of the mode of incorporation of chlorinated benzenes on their substitution pattern.

  19. Determination of tetrachloroethylene and other volatile halogenated organic compounds in oil wastes by headspace SPME GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, D.; Bezzi, R.; Torri, C.; Galletti, P.; Tagliavini, E. [Bologna Univ., Ravenna (Italy). Lab. of Chemistry, C.I.R.S.A

    2007-09-15

    Oil wastes and slops are complex mixtures of hydrocarbons, which may contain a variety of contaminants including tetrachloroethylene (perchloroethylene, PCE) and other volatile halogenated organic compounds (VHOCs). The analytical determination of PCE at trace levels in petroleum-derived matrices is difficult to carry out in the presence of large amounts of hydrocarbon matrix components. In the following study, we demonstrate that headspace solid-phase microextraction (HS-SPME) combined with GC-MS analysis can be applied for the rapid measurement of PCE concentration in oil samples. The HS-SPME method was developed using liquid paraffin as matrix matching reference material for external and internal calibration and optimisation of experimental parameters. The limit of quantitation was 0.05 mg kg{sup -1}, and linearity was established up to 25 mg kg{sup -1}. The HS-SPME method was extended to several VHOCs, including trichloroethylene (TCE) in different matrices and was applied to the quantitative analysis of PCE and TCE in real samples.

  20. Typical halogenated persistent organic pollutants in indoor dust and the associations with childhood asthma in Shanghai, China.

    Science.gov (United States)

    Meng, Ge; Nie, Zhiqing; Feng, Yan; Wu, Xiaomeng; Yin, Yong; Wang, Yan

    2016-04-01

    Halogenated persistent organic pollutants (Hal-POPs) are significant contaminants in the indoor environment that are related to many human diseases. Ingestion of indoor dust is considered the major pathway of Hal-POP exposures, especially for children aged 3-6 years. Alongside a retrospective study on the associations between typical Hal-POP exposure and childhood asthma in Shanghai, indoor dust samples from asthmatic and non-asthmatic children's homes (n = 60, each) were collected. Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured by GC-MS. BDE-209, PCB-8 and p,p'-DDE were the predominant components in each chemical category. The concentrations of most Hal-POPs were significantly higher in the asthmatic families. The associations between Hal-POP exposure and asthma occurrence were examined by calculating the odds ratios (ORs) using a logistic regression model. A positive association was found between p,p'-DDE in indoor dust and childhood asthma (OR = 1.825, 95%CI: 1.004, 3.317; p = 0.048). The average daily doses of Hal-POP intake were calculated using the method provided by the USEPA. Non-carcinogenic health risks were preliminarily assessed. Our study indicated that exposure to p,p'-DDE via indoor dust may contribute to childhood asthma occurrence. Non-carcinogenic health risks were not found with the intake of Hal-POPs via the ingestion of indoor dust.

  1. Biomarker responses associated with halogenated organic contaminants in northern fulmars (Fulmarus glacialis) breeding in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Braune, Birgit M., E-mail: birgit.braune@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, K1A 0H3 (Canada); Trudeau, Suzanne [Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, K1A 0H3 (Canada); Jeffrey, Deborah A. [Bancroft, Ontario, K0L 1C0 (Canada); Mallory, Mark L. [Environment Canada, Box 1714, Iqaluit, Nunavut, X0A 0H0 (Canada)

    2011-10-15

    We examined relationships between hepatic concentrations of halogenated organic contaminants and ethoxyresorufin O-deethylase (EROD) activity and retinoid (vitamin A) concentrations in livers, as well as retinol and thyroid hormone (TT{sub 3}, TT{sub 4}) levels in blood plasma, of northern fulmars at two breeding colonies in the Canadian High Arctic. Biomarker levels or responses did not differ significantly between males and females at either colony, nor was there any significant difference between colonies. No significant relationships were found between thyroid hormone or hepatic retinoid concentrations and any of the dioxin-like compounds or their Toxic Equivalents (TEQs) although significant positive correlations were found with plasma retinol (p < 0.03). EROD activity was significantly correlated with hepatic dioxin-like compounds and their TEQs (p < 0.001) as well as total PCBs (p < 0.01), which suggests that EROD induction occurs in northern fulmars at environmentally-relevant concentrations. - Highlights: > EROD induction occurs in northern fulmars at environmentally-relevant concentrations. > No relationships between hepatic retinoid or plasma thyroid hormone levels and dioxin-like compounds or TEQs. > Biomarker responses did not differ between males and females or between colonies. - EROD induction occurs in northern fulmars in the Canadian Arctic at environmentally-relevant concentrations.

  2. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    Chlorinated fatty acids have been found to be major contributors to organohalogen compounds in fish, bivalves, jellyfish, and lobster, and they have been indicated to contribute considerably to organohalogens in marine mammals. Brominated fatty acids have been found in marine sponges. Also......, chlorinated lipids have been found in meat exposed to hypochlorite disinfected water, and in chlorine-treated flour and in products made from such flour. Following exposure to chlorine bleached pulp mill effluents, aquatic organisms may have elevated concentrations of chlorinated fatty acids in their lipids....... However, a natural production of halogenated fatty acids is also possible. In this paper we summarize the present knowledge of the occurrence of halogenated fatty acids in lipids and suggested ways of their formation. In Part II (Trends Anal. Chem. 16 (1997) 274) we deal with methods...

  3. Influence of saponins on the biodegradation of halogenated phenols.

    Science.gov (United States)

    Kaczorek, Ewa; Smułek, Wojciech; Zdarta, Agata; Sawczuk, Agata; Zgoła-Grześkowiak, Agnieszka

    2016-09-01

    Biotransformation of aromatic compounds is a challenge due to their low aqueous solubility and sorptive losses. The main obstacle in this process is binding of organic pollutants to the microbial cell surface. To overcome these, we applied saponins from plant extract to the microbial culture, to increase pollutants solubility and enhance diffusive massive transfer. This study investigated the efficiency of Quillaja saponaria and Sapindus mukorossi saponins-rich extracts on biodegradation of halogenated phenols by Raoultella planticola WS2 and Pseudomonas sp. OS2, as an effect of cell surface modification of tested strains. Both strains display changes in inner membrane permeability and cell surface hydrophobicity in the presence of saponins during the process of halogenated phenols biotransformation. This allows them to more efficient pollutants removal from the environment. However, only in case of the Pseudomonas sp. OS2 the addition of surfactants to the culture improved effectiveness of bromo-, chloro- and fluorophenols biodegradation. Also introduction of surfactant allowed higher biodegradability of halogenated phenols and can shorten the process. Therefore this suggests that usage of plant saponins can indicate more successful halogenated phenols biodegradation for selected strains.

  4. EPA's (Environmental Protection Agency's) draft drinking-water criteria document for monochlorobenzene. Technical comments of the Halogenated Organics Subcommittee. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-16

    The Halogenated Organics Subcommittee evaluated the animal evidence for carcinogencity of chlorobenzene to be inadequate under EPA's new guidelines based on the lack of a statistically significant increase in the incidence of tumors in female mice, male mice and female rats, and on the basis of the perception of a diminished biologic significance of reported malignant neoplastic nodules of the liver in the highest dose-treated male rats. The evidence would place chlorobenzene into the overall weight-of-the-evidence category D (not classified).

  5. Legacy and new halogenated persistent organic pollutants in polar bears from a contamination hotspot in the Arctic, Hudson Bay Canada.

    Science.gov (United States)

    Letcher, R J; Morris, A D; Dyck, M; Sverko, E; Reiner, E J; Blair, D A D; Chu, S G; Shen, L

    2017-08-10

    A large and complex suite of 295 legacy and new halogenated persistent organic pollutants (POPs) were investigated in fat or liver tissue samples of polar bears collected in 2013-2014 from Southern (SHB) and Western (WHB) subpopulations of the Canadian Arctic contaminants hotspot of Hudson Bay. A total of 210 POPs were detected and/or quantifiable with some frequency in all fat or liver samples. POP profile and concentration differences were investigated both within (e.g. age and sex) and between the two subpopulations. Two time-point comparisons were made relative to POPs reported for Hudson Bay polar bears harvested in 2007-2008. ΣPolychlorinated biphenyl (PCB) concentrations at both time points were the most concentrated of the POP groups, and were spatially uniform with no detectable influence of sex or age, as were concentrations of the dominant congener CB153. ΣChlordanes (ΣCHLs, 74-79% oxychlordane) and the Σperfluoroalkyl substances (ΣPFASs, ≈60% perfluorooctane sulfonate (PFOS)) had the second greatest POP group concentrations in SHB and WHB respectively, with ΣPFASs and ΣCHLs being significantly influenced by age and/or sex. ΣCHLs were spatially uniform but ΣPFASs were greater in the SHB bears, as were e.g. some flame retardants, due to e.g. local contamination and/or changes in bear behavior and diet. Endosulfans and hexabromocyclododecane were detectable in samples from 2007-2008 but not from 2013-2014, which is consistent with their global POP regulations. ΣPolychlorinated naphthalenes (ΣPCNs) were consistently detected at relatively high concentrations compared to other arctic wildlife, however these concentrations were low relative to legacy POPs. ΣShort-chain chlorinated paraffins (ΣSCCPs) were major contributors to the overall POPs burden with concentrations comparable to other legacy POPs, though there was no significant difference between or within subpopulations for PCNs or SCCPs. Except for octachlorostyrene, POPs concentrations

  6. On-Surface Synthesis of Two-Dimensional Covalent Organic Structures versus Halogen-Bonded Self-Assembly: Competing Formation of Organic Nanoarchitectures.

    Science.gov (United States)

    Peyrot, David; Silly, Fabien

    2016-05-24

    The competition between the on-surface synthesis of covalent nanoarchitectures and the self-assembly of star-shaped 1,3,5-Tris(4-iodophenyl)benzene molecules on Au(111) in vacuum is investigated using scanning tunneling microscopy above room temperature. The molecules form covalent polygonal nanoachitectures at the gold surface step edges and at the elbows of the gold reconstruction at low coverage. With coverage increasing two-dimensional halogen-bonded structures appear and grow on the surface terraces. Two different halogen-bonded nanoarchitectures are coexisting on the surface and hybrid covalent-halogen bonded structures are locally observed. At high coverage covalent nanoarchitectures are squeezed at the domain boundary of the halogen-bonded structures. The competitive growth between the covalent and halogen-bonded nanoarchitectures leads to formation of a two-layer film above one monolayer deposition. For this coverage, the covalent nanoarchitectures are propelled on top of the halogen-bonded first layer. These observations open up new opportunities for decoupling covalent nanoarchitectures from catalytically active and metal surfaces in vacuum.

  7. Organic electroluminescent devices having improved light extraction

    Science.gov (United States)

    Shiang, Joseph John

    2007-07-17

    Organic electroluminescent devices having improved light extraction include a light-scattering medium disposed adjacent thereto. The light-scattering medium has a light scattering anisotropy parameter g in the range from greater than zero to about 0.99, and a scatterance parameter S less than about 0.22 or greater than about 3.

  8. Halogenation of microcapsule walls

    Science.gov (United States)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  9. Non-target screening of extractable and non-extractable organic xenobiotics in riverine sediments of Ems and Mulde Rivers, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Kronimus, Alexander [Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, D-52056 Aachen (Germany)]. E-mail: kronimus@lek.rwth-aachen.de; Schwarzbauer, Jan [Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, D-52056 Aachen (Germany)]. E-mail: schwarzbauer@lek.rwth-aachen.de

    2007-05-15

    Subaquatic sediment samples derived form Elbe and Mulde Rivers, Germany, were analyzed for extractable and non-extractable anthropogenic organic compounds by a non-target screening approach. Applied methodologies were gas chromatography-mass spectrometry, dispersion extraction and degradation procedures, particularly alkaline and acidic hydrolysis, boron tribromide treatment, ruthenium tetroxide oxidation as well as pyrolysis and TMAH (tetramethylammonium hydroxide)-thermochemolysis. Numerous compounds were identified, including halogenated benzenes, anisoles, styrenes, alkanes, diphenylmethane derivates, anilines, phenols and diphenyl ethers. The results were interpreted with respect to compound specific modes of incorporation as well as to potential sources (e.g. municipal, agricultural, industrial). Extractable and non-extractable fractions differed significantly with respect to their qualitative and quantitative composition. For example, quantities in the extractable and non-extractable fractions of chlorinated benzenes differed up to factor 50. Among other significant results, the investigation revealed hints for a dependence of the mode of incorporation of chlorinated benzenes on their substitution pattern. - Analysis of both, extractable and non-extractable fraction of organic xenobiotics in sediments reveals a more detailed and comprehensive anthropogenic load profile.

  10. Extraction of organic compounds from brown coal

    Directory of Open Access Journals (Sweden)

    Slavomír Hredzák

    2005-11-01

    Full Text Available The paper presents the study on the extraction of organic compounds (low-molecular weight - diterpenes, high-molecular weight - fullerenes and humic acids from Handlová brown coal and pyrolytic soot. It was confirmed that the coal extract with a diterpene content - 16 β (H kaurene was obtained by the supercritical fluid extraction (using CO2 and modificator - tetrahydrofurane/acetone, 8:2 w/w at T = 90 oC and p = 30 MPa. The occurrence of fullerenes in the toluene extract of solid carbon product has confirmed by the MALDI - TOF - MS and UV-VIS spectroscopy. In the extraction process of GACL (Grinding Aqueous Caustic Leaching at the concentration of 0.1 % NaOH, the content of humic acids (HK in the physically untreated and pretreated sample increased by 6.09 and 4.57 times, respectively. In the case of higher leaching agent concentration (2 % NaOH, the content of HK in the physically untreated and pretreated sample increased by 8,67 and 8,21 times, respectively.

  11. Nitric oxide production inhibition and anti-mycobacterial activity of extracts and halogenated sesquiterpenes from the Brazilian red alga laurencia dendroidea J. Agardh

    Directory of Open Access Journals (Sweden)

    Thatiana Lopes Biá Ventura

    2015-01-01

    Full Text Available Background: Red algae of the genus Laurencia J. V. Lamouroux are a rich source of secondary metabolites with important pharmacological activities such as anti-tumoral, anti-inflammatory, anti-fungal, anti-viral, anti-leishmanial, anti-helminthic, anti-malarial, anti-trypanosomal, anti-microbial as well as anti-bacterial against Mycobacterium tuberculosis. Objective: In the present study, we evaluated the inhibition of nitric oxide (NO and tumor necrosis factor-a production and the anti-mycobacterial activity of crude extracts from the red Alga Laurencia dendroidea (from the South-Eastern coast of Brazil. Halogenated sesquiterpenes elatol (1, obtusol (2 and cartilagineol (3, previously isolated from this Alga by our group, were also studied. Materials and Methods: The lipopolysaccharide-activated macrophage cells (RAW 264.7 were used as inflammation model. Cytotoxic effect was determined using a commercial  lactate dehydrogenase (LDH kit and 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay. The growing Mycobacterium inhibition was verified against Mycobacterium bovis Bacillus Calmette-Guιrin and M. tuberculosis H 37 Rv strains. Results: The crude extract from Alga collected at Angra dos Reis, RJ, Brazil, was the most active inhibitor of both mycobacterial growth (half maximal inhibitory concentration [IC 50 ] 8.7 ± 1.4 mg/mL and NO production by activated macrophages (IC 50 5.3 ± 1.3 mg/mL. The assays with isolated compounds revealed the anti-mycobacterial activity of obtusol (2, whereas (--elatol (1 inhibited the release of inflammatory mediators, especially NO. To our knowledge, this is the first report describing an anti-mycobacterial effect of L. dendroidea extract and demonstrating the association of this activity with obtusol (2. Conclusion: The described effects of active compounds from L. dendroidea are promising for the control of inflammation in infectious diseases and specifically, against mycobacterial

  12. Organic solvents in electromembrane extraction: recent insights

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-01-01

    Electromembrane extraction (EME) was invented in 2006 as a miniaturized sample preparation technique for the separation of ionized species from aqueous samples. This concept has been investigated in different areas of analytical chemistry by different research groups worldwide since the introduct......Electromembrane extraction (EME) was invented in 2006 as a miniaturized sample preparation technique for the separation of ionized species from aqueous samples. This concept has been investigated in different areas of analytical chemistry by different research groups worldwide since...... the introduction. Under the influence of an electrical field, EME is based on electrokinetic migration of the analytes through a supported liquid membrane (SLM), which is an organic solvent immobilized in the pores of the polymeric membrane, and into the acceptor solution. Up to date, close to 150 research...... articles with focus on EME have been published. The current review summarizes the performance of EME with different organic solvents and discusses several criteria for efficient solvents in EME. In addition, the authors highlight their personal perspective about the most promising organic solvents for EME...

  13. Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer–chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS)

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B.; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A.; Schimmelmann, Arndt

    2017-01-01

    Rationale: Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems.

  14. Blue emitting halogen-phenoxy substituted 1,8-naphthalimides for potential organic light emitting diode applications

    Science.gov (United States)

    Ulla, Hidayath; Raveendra Kiran, M.; Garudachari, B.; Satyanarayan, M. N.; Umesh, G.; Isloor, A. M.

    2014-11-01

    In this paper, we report the synthesis and characterization of six 1,8-naphthalimides [4a-4c and 5a-5c] obtained by the substitution of electron donating halogen-phenoxy groups at the C-4 position. The derivatives were characterized using 1H NMR, 13C NMR, mass spectra, FT-IR, single crystal XRD; photo-physical, thermal, surface morphological and electrochemical properties were also investigated. The derivatives exhibit deep blue photoluminescence in the range 414-423 nm (in CHCl3) and 457-466 nm (in thin film state) on UV excitation with high Stokes' shifts and good chromaticity. The TGA and DSC analysis showed that the derivatives possess good thermal stability (271-284 °C) and melting points (138-201 °C). The HOMO and LUMO energy levels estimated by cyclic voltammetry are in the range 6.21-6.34 eV and 3.31-3.41 eV respectively corresponding to energy band gaps of 2.98-3.15 eV. These energy values are relatively higher than the commonly used electron transporting materials. The optical and electronic properties of the derivatives were tuned by the introduction of different electron donating halogen-phenoxy groups through C-4 position of the naphthalimide moiety. The emissive and electron-transporting properties of the naphthalimide derivative 4a were studied by fabricating a bi-layer and tri-layer devices. Further a phosphorescent device with 4a as electron transport layer (ETL) exhibited superior performance than the device without any ETL and was comparable with the device using standard Alq3 as ETL. These results indicate that the synthesized naphthalimide derivatives could play an important role in the development of OLEDs.

  15. Analysis of halogenated and priority pesticides at different concentration levels. Automated SPE extraction followed by isotope dilution-GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Planas, C.; Saulo, J.; Rivera, J.; Caixach, J. [Institut Investigacions Quimiques i Ambientals (IIQAB-CSIC), Barcelona (Spain)

    2004-09-15

    In this work, automatic SPE extraction of 16 pesticides and metabolites with the automated Power-Prep trademark system is evaluated at different concentration levels using polymeric (ENV+) and C{sub 18} sorbent phases. The method was optimised by comparing recoveries obtained using different eluting solvents. The optimised procedure was then applied to spiked water samples at concentration levels of 0.1{mu}g/L (quality standard for individual pesticides in drinking water) and 0.02{mu}g/L (close to the detection limit of most pesticides).

  16. Pop-like halogenated natural products in antarctic sponges

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, W. [Hohenheim Univ., Stuttgart (Germany); Janussen, D. [Senckenbergische Naturforschende Gesellschaft (Natur-Museum und Forschungs-Institut), Frankfurt am Main (Germany)

    2004-09-15

    Persistent organic pollutants (POPs) are major contaminants of our days. This group of chemicals comprises a number of halogenated compounds used as pesticides (DDT, lindane, chlordane, toxaphene and others) as well as industrial chemicals (PCBs, PCNs, CPs, and brominated flameretardants). Although the list of known POPs including isomers and metabolites is long, there are frequent reports on the detection of unknown organohalogen compounds in the literature. Recent work demonstrated that some of these unknown peaks in gas chromatograms originate from halogenated natural products (HNPs). Sometimes, HNPs have been found at remarkably high concentrations in marine birds, mammals and fish. Due to the structural similarities with anthropogenic POPs, these substances may possess a potential risk for wildlife and man. HNPs are known to be produced with an overwhelming variety by marine organisms such as algae, sponges, microorganisms and others. In this study we have screened different species of Antarctic sponges on the occurrence of halogenated compounds which may be of environmental concern. Thus, we were only interested in lipophilic and persistent HNPs. Following that, we applied our standard sample clean-up procedure for the analysis of nonpolar POPs. Two steps on deactivated and activated silica yielded compounds with similar polarity as PCBs, chloropesticides and brominated analogues in the sample extracts. Additionally, all samples were treated with concentrated sulphuric acid in order to eliminate labile (non-presistent) HNPs.

  17. Nitric Oxide Production Inhibition and Anti-Mycobacterial Activity of Extracts and Halogenated Sesquiterpenes from the Brazilian Red Alga Laurencia Dendroidea J. Agardh.

    Science.gov (United States)

    Biá Ventura, Thatiana Lopes; da Silva Machado, Fernanda Lacerda; de Araujo, Marlon Heggdorne; de Souza Gestinari, Lísia Mônica; Kaiser, Carlos Roland; de Assis Esteves, Francisco; Lasunskaia, Elena B; Soares, Angélica Ribeiro; Muzitano, Michelle Frazão

    2015-10-01

    Red algae of the genus Laurencia J. V. Lamouroux are a rich source of secondary metabolites with important pharmacological activities such as anti-tumoral, anti-inflammatory, anti-fungal, anti-viral, anti-leishmanial, anti-helminthic, anti-malarial, anti-trypanosomal, anti-microbial as well as anti-bacterial against Mycobacterium tuberculosis. In the present study, we evaluated the inhibition of nitric oxide (NO) and tumor necrosis factor-α production and the anti-mycobacterial activity of crude extracts from the red Alga Laurencia dendroidea (from the South-Eastern coast of Brazil). Halogenated sesquiterpenes elatol (1), obtusol (2) and cartilagineol (3), previously isolated from this Alga by our group, were also studied. The lipopolysaccharide-activated macrophage cells (RAW 264.7) were used as inflammation model. Cytotoxic effect was determined using a commercial lactate dehydrogenase (LDH) kit and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The growing Mycobacterium inhibition was verified against Mycobacterium bovis Bacillus Calmette-Guérin and M. tuberculosis H37 Rv strains. The crude extract from Alga collected at Angra dos Reis, RJ, Brazil, was the most active inhibitor of both mycobacterial growth (half maximal inhibitory concentration [IC50] 8.7 ± 1.4 μg/mL) and NO production by activated macrophages (IC50 5.3 ± 1.3 μg/mL). The assays with isolated compounds revealed the anti-mycobacterial activity of obtusol (2), whereas (-)-elatol (1) inhibited the release of inflammatory mediators, especially NO. To our knowledge, this is the first report describing an anti-mycobacterial effect of L. dendroidea extract and demonstrating the association of this activity with obtusol (2). The described effects of active compounds from L. dendroidea are promising for the control of inflammation in infectious diseases and specifically, against mycobacterial infections associated with exacerbated inflammation. Inflammation is strongly involved

  18. Qualitative analysis of halogenated organic contaminants in American eel by gas chromatography/time-of-flight mass spectrometry.

    Science.gov (United States)

    Byer, Jonathan D; Pacepavicius, Grazina; Lebeuf, Michel; Brown, R Stephen; Backus, Sean; Hodson, Peter V; Alaee, Mehran

    2014-12-01

    Target compound analysis with scanning mass spectrometers such as quadrupole or magnetic sector instruments is used extensively in environmental chemistry because of the selectivity, sensitivity, and robustness. Yet, target compound analysis selectively ignores the majority of compounds present in a sample, especially in complex matrices like fish. In this study, time-of-flight mass spectrometry was used to screen for and identify halogenated compounds in American eels (Anguilla rostrata). Individual and then pooled eel samples were analysed using electron ionization and electron capture negative ionization (ECNI) modes. Eels were differentiated by principal component analysis of chemical profiles and were grouped corresponding to their capture location, all with a single instrument injection per sample. Bromine containing compounds were further investigated by taking advantage of the selectivity of ECNI by utilizing the Br(-) ion m/z 79 and 81. A total of 51 brominated compounds were detected and their identities were attempted by authentic standards, library searching, and/or chemical formula prediction based on accurate mass measurements. Several PBDEs were identified in the samples, and the majority of the non-PBDEs identified were bromophenols, bromoanisoles, and bromobenzenes. These classes of compounds are synthesized for use in flame retardant production either as intermediates or as final products. However, their occurrence in eels was most likely the result of metabolism or break-down products of high production volume flame retardants like polybrominated diphenyl ethers and bromophenoxy compounds. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Catalytic mechanisms, basic roles, and biotechnological and environmental significance of halogenating enzymes

    Institute of Scientific and Technical Information of China (English)

    Xianping Chen; Karl-Heinz van Pée

    2008-01-01

    The understanding of enzymatic incorporation of halogen atoms into organic molecules has increased during the last few years. Two novel types of halogenating enzymes, flavindependent halogenases and α-ketoglutarate-dependent halogenases, are now known to play a significant role in enzyme-catalyzed halogenation. The recent advances on the halogenating enzymes RebH, SyrB2, and CytC3 have suggested some new mechanisms for enzymatic halogenations. This review concentrates on the occurrence, catalytic mechanisms, and biotechnological applications of the halogenating enzymes that are currently known.

  20. Occurrence and concentrations of selected trace elements and halogenated organic compounds in stream sediments and potential sources of polychlorinated biphenyls, Leon Creek, San Antonio, Texas, 2012–14

    Science.gov (United States)

    Wilson, Jennifer T.

    2016-06-23

    The Texas Department of State Health Services issued fish consumption advisories in 2003 and 2010 for Leon Creek in San Antonio, Texas, based on elevated concentrations of polychlorinated biphenyls (PCBs) in fish tissues. The U.S. Geological Survey (USGS) measured elevated PCB concentrations in stream-sediment samples collected during 2007–9 from Leon Creek at Lackland Air Force Base (now known as Joint Base San Antonio-Lackland; the sampling site at this base is hereinafter referred to as the “Joint Base site”) and sites on Leon Creek downstream from the base. This report describes the occurrence and concentrations of selected trace elements and halogenated organic compounds (pesticides, flame retardants, and PCBs) and potential sources of PCBs in stream-sediment samples collected from four sites on Leon Creek during 2012–14. In downstream order, sediment samples were collected from Leon Creek at northwest Interstate Highway 410 (Loop 410), Rodriguez Park, Morey Road, and Joint Base. The USGS periodically collected streambed-sediment samples during low flow and suspended-sediment samples during high flow.

  1. Relationship between persistent halogenated organic contaminants and TCDD-toxic equivalents on EROD activity and retinoid and thyroid hormone status in northern fulmars.

    Science.gov (United States)

    Helgason, Lisa B; Verreault, Jonathan; Braune, Birgit M; Borgå, Katrine; Primicerio, Raul; Jenssen, Bjørn M; Gabrielsen, Geir W

    2010-11-15

    We investigated whether the hepatic cytochrome P450 1A activity (measured as 7-ethoxyresorufin-O-deethylase (EROD)) and plasma thyroid hormone and liver retinoid concentrations were explained by liver and blood levels of halogenated organic contaminants (HOCs) in free-ranging breeding northern fulmars (Fulmarus glacialis) from Bjørnøya in the Norwegian Arctic. Hepatic EROD activity and liver levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) were positively correlated, suggesting that hepatic EROD activity is a good indicator for dioxin and dioxin-like HOC exposure in breeding northern fulmars. There were not found other strong relationships between HOC concentrations and hepatic EROD activity, plasma thyroid or liver retinoid concentrations in the breeding northern fulmars. It is suggested that the HOC levels found in the breeding northern fulmars sampled on Bjørnøya were too low to affect plasma concentrations of thyroid hormones and liver levels of retinol and retinyl palmitate, and that hepatic EROD activity is a poor indicator of polychlorinated biphenyl (PCB) and pesticide exposure.

  2. Retention of Halogenated Solutes on Stationary Phases Containing Heavy Atoms

    Directory of Open Access Journals (Sweden)

    Toshio Miwa

    2013-05-01

    Full Text Available To examine the effects of weak intermolecular interactions on solid-phase extraction (SPE and chromatographic separation, we synthesized some novel stationary phases with a heavy atom effect layer by immobilizing halogenated aromatic rings and hydroxyl groups onto the surface of a hydrophilic base polymer. Using SPE cartridges packed with the functionalized materials, we found that the heavy atom stationary phases could selectively retain halophenols in organic solvents, such as 1-propanol which blocks the hydrogen bonding, or acetonitrile which blocks the p-p interaction. The extraction efficiency of the materials toward the halophenols depended on the dipole moments of phenoxy groups present as functional groups. On the other hand, the extraction efficiency of solutes toward the functional group depended on their molar refractions, i.e., induced dipole moments. The retention of the solutes to the stationary phase ultimately depended on not only strong intermolecular interactions, but also the effects of weak interactions such as the dispersion force.

  3. Halogens in the troposphere.

    Science.gov (United States)

    Finlayson-Pitts, Barbara J

    2010-02-01

    Although inorganic halogen gases are believed to play key roles in the chemistry of the lower atmosphere, many of them have not yet been detected or measured in ambient air. This article describes some of the current techniques and future needs for inorganic halogens in air. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.).

  4. Organic light emitting diode with light extracting electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Abhinav; Buhay, Harry

    2017-04-18

    An organic light emitting diode (10) includes a substrate (20), a first electrode (12), an emissive active stack (14), and a second electrode (18). At least one of the first and second electrodes (12, 18) is a light extracting electrode (26) having a metallic layer (28). The metallic layer (28) includes light scattering features (29) on and/or in the metallic layer (28). The light extracting features (29) increase light extraction from the organic light emitting diode (10).

  5. A comparison of chlorinated organic material produced by chlorine and chlorine dioxide bleaching

    Energy Technology Data Exchange (ETDEWEB)

    McKaque, A.B.; Reeve, D.W. [Univ. of Toronto (Canada)

    1995-12-31

    Chlorine and chlorine dioxide react differently with pulp during bleaching and produce different types of organic by-products. The main differences are the large reduction in the amount of AOX (adsorbable organic halogen) in the effluent and EOX (extractable organic halogen) in the pulp. This talk reviews the differences in the amounts and types of chlorinated organic by-products produced by the two different bleaching agents.

  6. Volatile halogenated hydrocarbons in foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Toyoda, Masatake; Saito, Yukio [National Institute of Health Services, Tokyo (Japan)] [and others

    1995-02-01

    Volatile halogenated organic compounds were determined in foods. Statistical treatment of the data for 13 sampled from 20 families living in suburban Tokyo (Saitama prefecture) indicated that the foods were contaminated by water pollution and/or substances introduced by the process of food production. Butter and margarine were contaminated by chlorinated ethylene, ethane, and related compounds released by dry cleaning and other operations. Soybean sprouts and tofu (soybean curd) contained chloroform and related trihalomethanes absorbed during the production process. 27 refs., 6 figs., 5 tabs.

  7. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao

    2015-12-02

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  8. Halogen-bonding-triggered supramolecular gel formation.

    Science.gov (United States)

    Meazza, Lorenzo; Foster, Jonathan A; Fucke, Katharina; Metrangolo, Pierangelo; Resnati, Giuseppe; Steed, Jonathan W

    2013-01-01

    Supramolecular gels are topical soft materials involving the reversible formation of fibrous aggregates using non-covalent interactions. There is significant interest in controlling the properties of such materials by the formation of multicomponent systems, which exhibit non-additive properties emerging from interaction of the components. The use of hydrogen bonding to assemble supramolecular gels in organic solvents is well established. In contrast, the use of halogen bonding to trigger supramolecular gel formation in a two-component gel ('co-gel') is essentially unexplored, and forms the basis for this study. Here, we show that halogen bonding between a pyridyl substituent in a bis(pyridyl urea) and 1,4-diiodotetrafluorobenzene brings about gelation, even in polar media such as aqueous methanol and aqueous dimethylsulfoxide. This demonstrates that halogen bonding is sufficiently strong to interfere with competing gel-inhibitory interactions and create a 'tipping point' in gel assembly. Using this concept, we have prepared a halogen bond donor bis(urea) gelator that forms co-gels with halogen bond acceptors.

  9. Halogenated solvent remediation

    Science.gov (United States)

    Sorenson, Kent S.

    2004-08-31

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. A preferred method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof. Especially preferred compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the composition.

  10. Marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Kucklick, John R.; Pugh, Rebecca S.; Becker, Paul R. [Hollings Marine Laboratory, National Institute of Standards and Technology (NIST), Charleston, SC (United States); Schantz, Michele M.; Porter, Barbara J.; Poster, Dianne L.; Leigh, Stefan; Wise, Stephen A. [NIST, Analytical Chemistry Division, Gaithersburg, MD (United States); Rowles, Teri K. [National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD (United States)

    2010-05-15

    The National Institute of Standards and Technology (NIST) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. Standard Reference Material (SRM) 1945 Organics in Whale Blubber was recertified for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, and polybrominated diphenyl ether (PBDE) congeners. SRM 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congeners, coplanar PCBs, and methoxylated PBDE congeners which are natural products. NIST also has assigned mass fraction values, as a result of interlaboratory comparison exercises, for PCB congeners, organochlorine pesticides, PBDE congeners, and fatty acids in six homogenate materials produced from marine mammal blubber or serum. The materials are available from NIST upon request; however, the supply is very limited for some of the materials. The materials include those obtained from pilot whale blubber (Homogenates III and IV), Blainville's beaked whale blubber (Homogenate VII), polar bear fat (Homogenate VI), and California sea lion serum (Marine Mammal Control Material-1 Serum) and blubber (Homogenate V). (orig.)

  11. Cytotoxicity of halogenated graphenes

    Science.gov (United States)

    Teo, Wei Zhe; Khim Chng, Elaine Lay; Sofer, Zdeněk; Pumera, Martin

    2013-12-01

    Graphene and its family of derivatives possess unique and remarkable physicochemical properties which make them valuable materials for applications in many areas like electronics, energy storage and biomedicine. In response to the possibility of its large-scale manufacturing as commercial products in the future, an investigation was conducted to determine the cytotoxicity of one particular family of graphene derivatives, the halogenated graphenes, for the first time. Halogenated graphenes were prepared through thermal exfoliation of graphite oxide in gaseous chlorine, bromine or iodine atmospheres to yield chlorine- (TRGO-Cl), bromine- (TRGO-Br) and iodine-doped graphene (TRGO-I) respectively. 24 h exposure of human lung carcinoma epithelial cells (A549) to the three halogenated graphenes and subsequent cell viability assessments using methylthiazolyldiphenyl-tetrazolium bromide (MTT) and water-soluble tetrazolium salt (WST-8) assays revealed that all the halogenated graphenes examined are rather cytotoxic at the concentrations tested (3.125 μg mL-1 to 200 μg mL-1) and the effects are dose-dependent, with TRGO-Cl reducing the cell viability to as low as 25.7% at the maximum concentration of 200 μg mL-1. Their levels of cytotoxicity can be arranged in the order of TRGO-Cl > TRGO-Br > TRGO-I, and it is suggested that the amount of halogen present in the graphene material is the determining factor for the observed trend. Control experiments were carried out to test for possible nanomaterial-induced interference as a consequence of reaction between the halogenated graphenes and the viability markers (MTT/WST-8 reagent) or binding of the formazan products under cell-free conditions. The data obtained eliminate the probability of significant influence by these interferents as the change in the normalized percentage of formazan formed is relatively small and thorough washings were performed prior to the viability assessments to reduce the amount of halogenated

  12. effect of organic extracts of bunium incrassatum on the ...

    African Journals Online (AJOL)

    S. Chentouh

    2017-09-01

    Sep 1, 2017 ... Keywords: Bunium incrassatum, Organic extract, Rabbits, Ovaries, Follicles, ... to evaluate the effect of the extract of this plant on the mature rabbit. ..... M.R., Kimiagar M., Mehrabi Y. The effects of omega-3 plus vitamin E and.

  13. The extraction of uranium using graphene aerogel loading organic solution.

    Science.gov (United States)

    Chen, Mumei; Li, Zheng; Li, Jihao; Li, Jingye; Li, Qingnuan; Zhang, Lan

    2017-05-01

    A new approach for uranium extraction employing graphene aerogel (GA) as a skeleton loading organic solution (GA-LOS) is proposed and investigated. Firstly, the GA with super-hydrophobicity and high organic solution absorption capacity was fabricated by one-step reduction and self-assembly of graphene oxide with ethylenediamine. By adsorbing Tri-n-butyl phosphate (TBP)/n-dodecane solution to prepare GA-LOS, the extraction of U(VI) from nitric acid medium using GA-LOS was investigated and compared with conventional solvent extraction. It is found that the GA-LOS method can provide several advantages over conventional solvent extraction and adsorption due to the elimination of aqueous-organic mixing-separation procedures and easy solid-liquid separation. Furthermore, it also possesses higher extraction capacity (the saturated extraction capacity of GA loading TBP for U(VI) was 316.3mgg(-1) ) and lower consumption of organic diluents, leading to less organic waste. Moreover, the stability of GA-LOS in aqueous solution and cycling test were also studied, and it shows a remarkable regeneration capability, making it an ideal candidate for metal extraction from aqueous solution.

  14. Halogen bonds in crystal engineering: like hydrogen bonds yet different.

    Science.gov (United States)

    Mukherjee, Arijit; Tothadi, Srinu; Desiraju, Gautam R

    2014-08-19

    used in the design of ternary cocrystals. Structural modularity in which an entire crystal structure is defined as a combination of modules is rationalized on the basis of the intermediate strength of a halogen bond. The specific directionality of the halogen bond makes it a good tool to achieve orthogonality in molecular crystals. Mechanical properties can be tuned systematically by varying these orthogonally oriented halogen···halogen interactions. In a further development, halogen bonds are shown to play a systematic role in organization of LSAMs (long range synthon aufbau module), which are bigger structural units containing multiple synthons. With a formal definition in place, this may be the right time to look at differences between halogen bonds and hydrogen bonds and exploit them in more subtle ways in crystal engineering.

  15. Aggregation in Organic Solutions of Malonamides: Consequences for Water Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Meridiano, Y.; Berthon, L.; Crozes, X.; Sorel, C. [CEA ValRho, DEN DRCP SCPS LCSE, F-30207 Bagnols Sur Ceze, (France); Dannus, P. [CEA Saclay, INSTN UEIN, F-91191 Gif Sur Yvette, (France); Antonio, M.R.; Chiarizia, R. [Argonne Natl Lab, CSE Div, Argonne, IL 60439 (United States); Zemb, T. [CEA CNRS UM2 ENSCM, Inst Chin Separat Marcoule, Bagnols Sur Ceze, (France)

    2009-07-01

    The molecular organization of N, N'-dimethyl-N, N'-dioctyl-hexyl-ethoxy-malonamide (DMDOHEMA), the current reference extractant for the DIAMEX (Diamide Extraction) process, is correlated with its water extraction properties from neutral media. The aggregation of DMDOHEMA in n-heptane was investigated by vapor pressure osmometry (VPO) and the aggregate speciation characterized by combined small-angle neutron and X-ray scattering (SANS and SAXS, respectively). Two approaches were taken to model the aggregation of the diamide and the water extraction as a function of the diamide concentration by taking into account a single aggregation equilibrium with an average aggregation number N equal to 4.28 {+-} 0.05; and a competition between two types of aggregates in the organic phase, namely, aggregates of the reverse micelle type with 4 diamides per aggregate, and an oligomeric structure composed of about 10 diamide molecules which appears at high extractant concentration ({>=} 1 mol/L). In both cases, the supramolecular speciation representing the monomers/aggregates distribution was determined, and for each supramolecular organization, a solubilization parameter was calculated using the Sergievskii-Dannus relationship. Thus, the correlation between the two types of micellization of the diamide and the extraction of water into the organic phase was demonstrated. The larger aggregates can extract about five times more water than monomers. (authors)

  16. Halogenation of cobalt dicarbollide

    Science.gov (United States)

    Hurlburt, Paul K.; Abney, Kent D.; Kinkead, Scott A.

    1997-01-01

    A method for selectively adding chlorine, bromine, or iodine to cobalt dicarbollide anions by means of electrophilic substitution reactions. Halogens are added only to the B10 and B10' positions of the anion. The process involves use of hypohalous acid or N-halosuccinimide or gaseous chlorine in the presence of iron.

  17. Species-specific bioaccumulation of halogenated organic pollutants and their metabolites in fish serum from an e-waste site, South China.

    Science.gov (United States)

    Zeng, Yan-Hong; Luo, Xiao-Jun; Zheng, Xiao-Bo; Tang, Bin; Wu, Jiang-Ping; Mai, Bi-Xian

    2014-10-01

    Halogenated organic pollutants (HOPs)-including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), polybromobiphenyls (PBBs), dechlorane plus (DP), tetrabromobisphenol A (TBBPA), and hexabromocyclododecanes (HBCDs) as well as PCB metabolites (methylsulfone [MeSO2-]) and hydroxylated (OH-) PCBs and OH-PBDEs-were determined in the serum of mud carp and northern snakehead from an electronic-waste (e-waste) site in South China. The average concentrations (mean ± SD) of ΣPCBs, ΣPBDEs, ΣOCPs, ΣPBBs, ΣTBBPA, ΣHBCDs, and ΣDP were 1410 ± 324, 70 ± 20, 3.0 ± 0.4, 2.8 ± 0.8, 1.6 ± 0.4, 1.0 ± 0.2, and 0.3 ± 0.03 ng/g wet weight (ww) in mud carp and 6430 ± 781, 468 ± 49, 22.4 ± 1.1, 7.0 ± 0.6, 2.9 ± 2.3, 5.5 ± 1.1, and 4.6 ± 0.6 ng/g ww in northern snakehead, respectively. MeSO2-PCBs, OH-PCBs, and OH-PBDEs were detected at a total concentration of 0.44 ± 0.03 and 9.7 ± 0.3 ng/g ww in mud carp and northern snakehead, respectively. The congener profiles of PCBs, PBDEs, OH/MeSO2-PCBs, and OH-PBDEs were found to be significantly different between the two fish species, possibly as a result of species-specific bioaccumulation and/or metabolism of the HOPs. Chirality of ten PCB congeners and α-HBCD, as well as the f anti values of DP in the serum samples, supported the species-specific biotransformation of HOPs. Furthermore, the presence of covaried and counter-varied enantiomeric fractions of PCBs between the two fish species indicated species- and congener-specific enantiomer enrichment of PCBs.

  18. Halogen versus halide electronic structure

    Institute of Scientific and Technical Information of China (English)

    Willem-Jan; van; Zeist; F.Matthias; Bickelhaupt

    2010-01-01

    Halide anions X-are known to show a decreasing proton affinity(PA),as X descends in the periodic table along series F,Cl,Br and I.But it is also well-known that,along this series,the halogen atom X becomes less electronegative(or more electropositive).This corresponds to an increasing energy of the valence np atomic orbital(AO) which,somewhat contradictorily,suggests that the electron donor capability and thus the PA of the halides should increase along the series F,Cl,Br,I.To reconcile these contradictory observations,we have carried out a detailed theoretical analysis of the electronic structure and bonding capability of the halide anions X-as well as the halogen radicals X-,using the molecular orbital(MO) models contained in Kohn-Sham density functional theory(DFT,at SAOP/TZ2P as well as OLYP/TZ2P levels) and ab initio theory(at the HF/TZ2P level).We also resolve an apparent intrinsic contradiction in Hartree-Fock theory between orbital-energy and PA trends.The results of our analyses are of direct relevance for understanding elementary organic reactions such as nucleophilic substitution(SN2) and base-induced elimination(E2) reactions.

  19. In-tube extraction of volatile organic compounds from aqueous samples: an economical alternative to purge and trap enrichment.

    Science.gov (United States)

    Laaks, Jens; Jochmann, Maik A; Schilling, Beat; Schmidt, Torsten C

    2010-09-15

    A novel in-tube extraction device (ITEX 2) for headspace sampling was evaluated for GC/MS analysis of aqueous samples. Twenty compounds of regulatory and drinking water quality importance were analyzed, including halogenated hydrocarbons, BTEX compounds (benzene, toluene, ethylbenzene, xylenes), fuel oxygenates, geosmin, and 2-methylisoborneol. Five commercially available sorbent traps were compared for their compound specific extraction yield. On the basis of the results, a mixed bed trap was prepared and evaluated. The extraction parameters were optimized to yield maximum sensitivity within the time of a GC run, to avoid unnecessary downtime of the system. Method detection limits of 1-10 ng L(-1) were achieved for volatile organic compounds (VOCs), which is much lower than demands by regulatory limit values. The performance of the ITEX system is similar to that of purge and trap systems, but it requires lower sample volumes and is less prone to contamination, much simpler, more flexible, and affordable. Average relative standard deviations below 10% were achieved for all analytes, and recoveries from spiked tap water samples were between 90% and 103%, mostly. The extraction is nonexhaustive, removing a fraction of 7% to 55% of the target compounds, depending on the air-water partitioning coefficients. The method was also tested with nonsynthetic samples, including tap, pond, and reservoir water and different soft drinks.

  20. Gold recovery by galvanic stripping of an anionic organic extractant

    Directory of Open Access Journals (Sweden)

    Lacerda D.F.C.

    2001-01-01

    Full Text Available The galvanic stripping technique for metal recovery uses commercial organic extractants containing a metal to be recovered. The organic phase is placed in contact with a solid metal reducer that allows electrochemical reactions to occur. One product of these reactions is a metal layer deposited on the surface of the reducer consisting of reduced species desorbed from the organic phase. Another product is metal ions from the reducer adsorbed onto the organic phase. This work presents results for gold recovery by galvanic stripping of strong-base anionic extractants of a quaternary amine salt, ALIQUAT336®, in xylene using solid zinc as the metal reducer. The parameters studied were contact time for the organic phase containing gold and the samples of the reducing zinc metal, temperature of the system, gold concentration in the organic phase and type of stirring used in the galvanic stripping system. Experiments showed results higher than 28% of gold recovery and an adherent film of gold on the zinc surface. The Arrhenius plot for gold recovery from the organic extractant suggests a change in the rate- controlling step from mixed control to diffusion control with increasing temperature in the range of 20 to 50ºC.

  1. Organic compounds of different extractability in total solvent extracts from soils of contrasting water repellency

    Science.gov (United States)

    Atanassova, Irena; Doerr, Stefan H.

    2010-05-01

    Previous studies examining organic compounds that may cause water-repellent behaviour of soils have typically focussed on analysing only the lipophilic fraction of extracted material. This study aimed to provide a more comprehensive examination by applying single- and sequential-accelerated solvent extraction (ASE), separation and analysis by GC/MS of the total solvent extracts of three soils taken from under eucalypt vegetation with different levels of water repellency. Water repellency increased in all the soils after extraction with DCM:MeOH (95:5), but was eliminated with iso-propanol/ammonia (95:5). Quantities of major lipid compound classes varied between solvents and soils. Iso-propanol/ammonia (95:5) solvent released saccharides, glycerol, aromatic acids and other polar organic compounds, which were more abundant in fractionated extracts from the single extraction and the third step sequential ASE extraction, than in the extracts from the DCM:MeOH ASE solvent. Dominant compounds extracted from all soils were long-chain alkanols (>C22), palmitic acid, C29 alkane, β-sitosterol, terpenes, terpenoids and other polar compounds. The soil with smallest repellency lacked >C18 fatty acids and had smallest concentrations of alkanols (C26, C28 and C30) and alkanes (C29, C31), but a greater abundance of more complex polar compounds than the more repellent soils. We therefore speculate that the above compounds play an important role in determining the water repellency of the soils tested. The results suggest that one-stage and sequential ASE extractions with iso-propanol:ammonia and subsequent fractionation of extracts are a useful approach in providing a comprehensive assessment of the potential compounds involved in causing soil water repellency.

  2. Historical trends in occurrence and atmospheric inputs of halogenated volatile organic compounds in untreated ground water used as a source of drinking water

    Science.gov (United States)

    Shapiro, S.D.; Busenberg, E.; Focazio, M.J.; Plummer, L.N.

    2004-01-01

    Analyses of samples of untreated ground water from 413 community-, non-community- (such as restaurants), and domestic-supply wells throughout the US were used to determine the frequency of detection of halogenated volatile organic compounds (VOCs) in drinking-water sources. The VOC data were compiled from archived chromatograms of samples analyzed originally for chlorofluorocarbons (CFCs) by purge-and-trap gas chromatography with an electron-capture detector (GC-ECD). Concentrations of the VOCs could not be ascertained because standards were not routinely analyzed for VOCs other than trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). Nevertheless, the peak areas associated with the elution times of other VOCs on the chromatograms can be classified qualitatively to assess concentrations at a detection limit on the order of parts per quadrillion. Three or more VOCs were detected in 100% (percent) of the chromatograms, and 77.2% of the samples contained 10 or more VOCs. The maximum number of VOCs detected in any sample was 24. Modeled ground-water residence times, determined from concentrations of CFC-12, were used to assess historical trends in the cumulative occurrence of all VOCs detected in this analysis, as well as the occurrence of individual VOCs, such as CFC-11, carbon tetrachloride (CCl4), chloroform and tetrachloroethene (PCE). The detection frequency for all of the VOCs detected has remained relatively constant from approximately 1940 to 2000; however, the magnitude of the peak areas on the chromatograms for the VOCs in the water samples has increased from 1940 to 2000. For CFC-11, CCl4, chloroform and PCE, small peaks decrease from 1940 to 2000, and large peaks increase from 1940 to 2000. The increase in peak areas on the chromatograms from analyses of more recently recharged water is consistent with reported increases in atmospheric concentrations of the VOCs. Approximately 44% and 6

  3. Selective Extraction of Organic Contaminants from Soil Using Pressurised Liquid Extraction

    Directory of Open Access Journals (Sweden)

    Rozita Osman

    2013-01-01

    Full Text Available This study focuses on the application of sorbents in pressurised liquid extraction (PLE cell to establish a selective extraction of a variety of organic contaminants (polycyclic aromatic hydrocarbons (PAHs, chlorpyrifos, phenol, pentachlorophenol, and sterols from soil. The selectivity and efficiency of each sorbent depend on the properties of the material, extracting solvent, capacity factor, organic compounds of interest, and PLE operating parameters (temperature, pressure, and extraction time. Several sorbents (silica, alumina, and Florisil were evaluated and with the proper choice of solvents, polar and nonpolar compounds were successfully separated in two fractions. Nonpolar compounds (PAHs, chlorpyrifos, and pentachlorophenol were recovered in the first fraction using a polar sorbent such as Florisil or alumina, and n-hexane as eluting solvent, while more polar compounds (phenol and sterols were recovered in the second fraction using methanol. Silica (5 g was found to be effective for selective extraction with the satisfactory recoveries for all compounds (PAHs from 87.1–96.2%, chlorpyrifos 102.9%, sterols from 93.7–100.5%, phenol 91.9%, and pentachlorophenol 106.2%. The efficiency and precision of this extraction approach and the existing EPA Method 3545 were compared.

  4. Non-conventional gas phase remediation of volatile halogenated compounds by dehydrated bacteria

    OpenAIRE

    Erable, Benjamin; Goubet, Isabelle; Seltana, Amira; Maugard, Thierry

    2009-01-01

    Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst. The hydrolysis of volatile halogenated substrates into the corresponding alcohol was studied in a solid/gas bio...

  5. 同时测定水中10种卤代有机挥发物的顶空气相色谱法%Simultaneous determination of 10 kinds of halogenated organic volatiles with headspace gas chromatography in water

    Institute of Scientific and Technical Information of China (English)

    尹华; 陈平; 陈振为

    2012-01-01

    [Objective]To establish a method for simultaneous determination of 10 kinds of volatile halogenated compounds with headspace-gas chromatography (HS-GC ) in water. [Methods]After separation of in water by CP-Sil 5CB capillarity column, 10 kinds of organic compounds were detected quantitatively by electron capture detector (ECD). [Results]The correlation coefficient of 10 kinds of organic compounds was 0. 999 1-0. 999 9, the average recovery was 89. 3%-105% (re = 6) , the RSD was 1.5%-5.5% , and the minimum detectable concentration was 0.30-20.16 μg/L. [Conclusion]The method is simple, rapid, accurate and sensitive, and it is suitable for the determination of halogenated organic compounds in water.%目的 建立同时测定生活饮用水中10种挥发性卤代化合物的顶空-气相色谱方法.方法 水中10种有机物经CP-Sil 5CB毛细管色谱柱分离,电子捕获检测器(ECD)检测,外标法定量.结果 10种有机物的线性相关系数为0.999 1 ~0.999 9,平均加样回收率为89.3% ~ 105% (n =6),RSD为1.5% ~5.5%,最低检出浓度为0.30 ~20.16.μg/L.结论 该方法操作简单,快速,准确,灵敏度较高,适用于水中卤代有机物的测定.

  6. Extraction of organic compounds with room temperature ionic liquids.

    Science.gov (United States)

    Poole, Colin F; Poole, Salwa K

    2010-04-16

    Room temperature ionic liquids are novel solvents with a rather specific blend of physical and solution properties that makes them of interest for applications in separation science. They are good solvents for a wide range of compounds in which they behave as polar solvents. Their physical properties of note that distinguish them from conventional organic solvents are a negligible vapor pressure, high thermal stability, and relatively high viscosity. They can form biphasic systems with water or low polarity organic solvents and gases suitable for use in liquid-liquid and gas-liquid partition systems. An analysis of partition coefficients for varied compounds in these systems allows characterization of solvent selectivity using the solvation parameter model, which together with spectroscopic studies of solvent effects on probe substances, results in a detailed picture of solvent behavior. These studies indicate that the solution properties of ionic liquids are similar to those of polar organic solvents. Practical applications of ionic liquids in sample preparation include extractive distillation, aqueous biphasic systems, liquid-liquid extraction, liquid-phase microextraction, supported liquid membrane extraction, matrix solvents for headspace analysis, and micellar extraction. The specific advantages and limitations of ionic liquids in these studies is discussed with a view to defining future uses and the need not to neglect the identification of new room temperature ionic liquids with physical and solution properties tailored to the needs of specific sample preparation techniques. The defining feature of the special nature of ionic liquids is not their solution or physical properties viewed separately but their unique combinations when taken together compared with traditional organic solvents.

  7. Subcritical-Water Extraction of Organics from Solid Matrices

    Science.gov (United States)

    Amashukeli, Xenia; Grunthaner, Frank; Patrick, Steven; Kirby, James; Bickler, Donald; Willis, Peter; Pelletier, Christine; Bryson, Charles

    2009-01-01

    An apparatus for extracting organic compounds from soils, sands, and other solid matrix materials utilizes water at subcritical temperature and pressure as a solvent. The apparatus, called subcritical water extractor (SCWE), is a prototype of subsystems of future instrumentation systems to be used in searching for organic compounds as signs of past or present life on Mars. An aqueous solution generated by an apparatus like this one can be analyzed by any of a variety of established chromatographic or spectroscopic means to detect the dissolved organic compound( s). The apparatus can be used on Earth: indeed, in proof-of-concept experiments, SCWE was used to extract amino acids from soils of the Atacama Desert (Chile), which was chosen because the dryness and other relevant soil conditions there approximate those on Mars. The design of the apparatus is based partly on the fact that the relative permittivity (also known as the dielectric constant) of liquid water varies with temperature and pressure. At a temperature of 30 C and a pressure of 0.1 MPa, the relative permittivity of water is 79.6, due to the strong dipole-dipole electrostatic interactions between individual molecular dipoles. As the temperature increases, increasing thermal energy causes increasing disorientation of molecular dipoles, with a consequent decrease in relative permittivity. For example, water at a temperature of 325 C and pressure of 20 MPa has a relative permittivity of 17.5, which is similar to the relative permittivities of such nonpolar organic solvents as 1-butanol (17.8). In the operation of this apparatus, the temperature and pressure of water are adjusted so that the water can be used in place of commonly used organic solvents to extract compounds that have dissimilar physical and chemical properties.

  8. Characteristics of volatile compounds removal in biogas slurry of pig manure by ozone oxidation and organic solvents extraction

    Institute of Scientific and Technical Information of China (English)

    Yujun Wang; Lianshuang Feng; Xiaosong Zhao; Xiulan Ma; Jingmin Yang; Huiqing Liu; Sen Dou

    2013-01-01

    Biogas slurry is not suitable for liquid fertilizer due to its high amounts of volatile materials being of complicated composition and peculiar smell.In order to remove volatiles from biogas slurry efficiently,the dynamic headspace and gas chromatography-mass spectrometry were used to clear the composition of volatiles.Nitrogen stripping and superfluous ozone were also used to remove volatiles from biogas slurry.The results showed that there were 21 kinds of volatile compounds in the biogas slurry,including sulfur compounds,organic amines,benzene,halogen generation of hydrocarbons and alkanes,some of which had strong peculiar smell.The volatile compounds in biogas slurry can be removed with the rate of 53.0% by nitrogen stripping and with rate of 81.7% by the oxidization and stripping of the superfluous ozone.On this basis,the removal rate of the volatile compounds reached 99.2%by chloroform and n-hexane extraction,and almost all of odor was eliminated.The contents of some dissolved organic compounds decreased obviously and however main plant nutrients had no significant change in the biogas slurry after being treated.

  9. Multi-contaminant analysis of organophosphate and halogenated flame retardants in food matrices using ultrasonication and vacuum assisted extraction, multi-stage cleanup and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Xu, Fuchao; García-Bermejo, Ángel; Malarvannan, Govindan; Gómara, Belén; Neels, Hugo; Covaci, Adrian

    2015-07-03

    A multi-residue analytical method was developed for the determination of a range of flame retardants (FRs), including polybrominated diphenyl ethers (PBDEs), emerging halogenated FRs (EFRs) and organophosphate FRs (PFRs), in food matrices. An ultrasonication and vacuum assisted extraction (UVAE), followed by a multi-stage clean-up procedure, enabled the removal of up to 1g of lipid from 2.5 g of freeze-dried food samples and significantly reduce matrix effects. UVAE achieves a waste factor (WF) of about 10%, while the WFs of classical QuEChERS methods range usually between 50 and 90%. The low WF of UVAE leads to a dramatic improvement in the sensitivity along with saving up to 90% of spiking (internal) standards. Moreover, a two-stage clean-up on Florisil and aminopropyl silica was introduced after UVAE, for an efficient removal of pigments and residual lipids, which led to cleaner extracts than normally achieved by dispersive solid phase extraction (d-SPE). In this way, the extracts could be concentrated to low volumes, e.g. <100 μL and the equivalent matrix concentrations were up to 100g ww/mL. The final analysis of PFRs was performed on GC-EI-MS, while PBDEs and EFRs were measured by GC-ECNI-MS. Validation tests were performed with three food matrices (lean beef, whole chicken egg and salmon filet), obtaining acceptable recoveries (66-135%) with good repeatability (RSD 1-24%, mean 7%). Method LOQs ranged between 0.008 and 0.04 ng/g dw for PBDEs, between 0.08 and 0.20 ng/g dw for EFRs, and between 1.4 and 3.6 ng/g dw for PFRs. The method was further applied to eight types of food samples (including meat, eggs, fish, and seafood) with lipid contents ranging from 0.1 to 22%. Various FRs were detected above MLOQ levels, demonstrating the wide-range applicability of our method. To the best of our knowledge, this is the first method reported for simultaneous analysis of brominated and organophosphate FRs in food matrices.

  10. Conversion and Extraction of Insoluble Organic Materials in Meteorites

    Science.gov (United States)

    Locke, Darren R.; Burton, Aaron S.; Niles, Paul B.

    2016-01-01

    We endeavor to develop and implement methods in our laboratory to convert and extract insoluble organic materials (IOM) from low car-bon bearing meteorites (such as ordinary chondrites) and Precambrian terrestrial rocks for the purpose of determining IOM structure and prebiotic chemistries preserved in these types of samples. The general scheme of converting and extracting IOM in samples is summarized in Figure 1. First, powdered samples are solvent extracted in a micro-Soxhlet apparatus multiple times using solvents ranging from non-polar to polar (hexane - non-polar, dichloromethane - non-polar to polar, methanol - polar protic, and acetonitrile - polar aprotic). Second, solid residue from solvent extractions is processed using strong acids, hydrochloric and hydrofluoric, to dissolve minerals and isolate IOM. Third, the isolated IOM is subjected to both thermal (pyrolysis) and chemical (oxidation) degradation to release compounds from the macromolecular material. Finally, products from oxidation and pyrolysis are analyzed by gas chromatography - mass spectrometry (GCMS). We are working toward an integrated method and analysis scheme that will allow us to determine prebiotic chemistries in ordinary chondrites and Precambrian terrestrial rocks. Powerful techniques that we are including are stepwise, flash, and gradual pyrolysis and ruthenium tetroxide oxidation. More details of the integrated scheme will be presented.

  11. Group extraction of organic compounds present in liquid samples

    Science.gov (United States)

    Jahnsen, Vilhelm J. (Inventor)

    1976-01-01

    An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.

  12. Antimicrobial (including antimollicutes, antioxidant and anticholinesterase activities of Brazilian and Spanish marine organisms – evaluation of extracts and pure compounds

    Directory of Open Access Journals (Sweden)

    Éverson Miguel Bianco

    2015-12-01

    Full Text Available Abstract This work describes the antimicrobial, antioxidant and anticholinesterase activities in vitro of organic extracts from fourteen seaweeds, eleven sponges, two ascidians, one bryozoan, and one sea anemone species collected along the Brazilian and Spanish coast, as well as the isolation of the diterpene (4R, 9S, 14S-4α-acetoxy-9β,14α-dihydroxydolast-1(15,7-diene (1 and halogenated sesquiterpene elatol (2. The most promising antimicrobial results for cell wall bacteria were obtained by extracts from seaweeds Laurencia dendroidea and Sargassum vulgare var. nanun (MIC 250 μg/ml, and by the bryozoan Bugula neritina (MIC 62.5 μg/ml, both against Staphylococcus aureus. As for antimollicutes, extracts from seaweeds showed results better than the extracts from invertebrates. Almost all seaweeds assayed (92% exhibited some antimicrobial activity against mollicutes strains (Mycoplasma hominis,Mycoplasma genitalium,Mycoplasma capricolum and Mycoplasma pneumoniae strain FH. From these seaweeds, A1 (Canistrocarpus cervicornis, A11 (Gracilaria sp. and A4 (Lobophora variegata showed the best results for M. pneumoniae strain FH (MIC 250 μg/ml. Furthermore, compounds 1 and 2 were also assayed against mollicutes strains M. hominis,M. genitalium,M. capricolum,M. pneumoniae strain 129 and M. pneumoniae strain FH, which showed MIC > 100 μg/ml. Antioxidant activities of extracts from these marine organisms were inactive, except for E7 (from sponge Ircinia sp., which exhibited moderated antioxidant activities for two methods assayed (IC50 83.0 ± 0.1 μg/ml, and 52.0 ± 0.8 mg AA/g, respectively. Finally, for the anticholinesterase activity, all the 29 samples evaluated (100% exhibited some level of activity, with IC50 < 1000 μg/ml. From these, seaweeds extracts were considered more promising than marine invertebrate extracts [A10 (IC50 14.4 ± 0.1 μg/ml, A16 (IC50 16.4 ± 0.4 μg/ml and A8 (IC50 14.9 ± 0.5 μg/ml]. The findings of this work are useful

  13. Removal of low molecular organic acids from aqueous solutions with reactive extraction

    National Research Council Canada - National Science Library

    Dominika Szternel; Magdalena Regel-Rosocka; Maciej Wiśniewski

    2013-01-01

    ...) from aqueous solutions with reactive extraction. The results specifically show that the extraction efficiency of acids depends on the type of extractant, diluents of the organic phase and the initial pH of the aqueous phase...

  14. Minimum amount of extracting solvent of AB/BC countercurrent extraction separation using organic feed

    Institute of Scientific and Technical Information of China (English)

    程福祥; 吴声; 张玻; 刘艳; 王嵩龄; 廖春生; 严纯华

    2014-01-01

    For an AB/BC countercurrent extraction separation using organic feed, the conditions to have minimum amount of ex-tracting solvent (Smin) and minimum amount of scrubbing agent solution (Wmin) were discussed, and the formulae of bothSmin and Wmin were deduced. It was shown that only when the ratio of flowrate of central component B leaving aqueous outlet to that leaving organic outlet took a certain optimal value, the AB/BC separation could have Smin as well asWmin, and this optimal ratio was decided by the separation factors between the three components but independent of feed composition.Smin was only relative to the separation factor of A/C pair but regardless of the separation factors of other pairs as well as feed composition, whereasWmin was determined by the separation factors between the components together with feed composition. Meanwhile it was also found that the organic stream out of feed stage was same composition as the initial organic feed when the separation system was given by the two minimum amounts and its steady state was achieved. Finally the results above were used to design a LuYb/YbTm separation case and the stage-wise compositions of each component in both the organic and the aqueous phase at steady state were given by computer simulation.

  15. Behavior of halogens during the degassing of felsic magmas

    Science.gov (United States)

    Balcone-Boissard, H.; Villemant, B.; Boudon, G.

    2010-09-01

    Residual concentrations of halogens (F, Cl, Br, I) and H2O in glass (matrix glass and melt inclusions) have been determined in a series of volcanic clasts (pumice and lava-dome fragments) of plinian, vulcanian and lava dome-forming eruptions. Felsic magmas from calc-alkaline, trachytic and phonolitic systems have been investigated: Montagne Pelée and Soufrière Hills of Montserrat (Lesser Antilles), Santa Maria-Santiaguito (Guatemala), Fogo (Azores) and Vesuvius (Italy). The behavior of halogens during shallow H2O degassing primarily depends on their incompatible character and their partitioning between melt and exsolved H2O vapor. However, variations in pre-eruptive conditions, degassing kinetics, and syn-eruptive melt crystallization induce large variations in the efficiency of halogen extraction. In all systems studied, Cl, Br and I are not fractionated from each other by differentiation or by degassing processes. Cl/Br/I ratios in melt remain almost constant from the magma reservoir to the surface. The ratios measured in erupted clasts are thus characteristic of pre-eruptive magma compositions and may be used to trace deep magmatic processes. F behaves as an incompatible element and, unlike the other halogens, is never significantly extracted by degassing. Cl, Br and I are efficiently extracted from melts at high pressure by H2O-rich fluids exsolved from magmas or during slow effusive magma degassing, but not during rapid explosive degassing. Because H2O and halogen mobility depends on their speciation, which strongly varies with pressure in both silicate melts and exsolved fluids, we suggest that the rapid pressure decrease during highly explosive eruptions prevents complete equilibrium between the diverse species of the volatiles and consequently limits their degassing. Conversely, degassing in effusive eruptions is an equilibrium process and leads to significant halogen output in volcanic plumes.

  16. Assessment of bioavailable organic phosphorus in tropical forest soils by organic acid extraction and phosphatase hydrolysis.

    Science.gov (United States)

    Darch, Tegan; Blackwell, Martin S A; Chadwick, David; Haygarth, Philip M; Hawkins, Jane M B; Turner, Benjamin L

    2016-12-15

    Soil organic phosphorus contributes to the nutrition of tropical trees, but is not accounted for in standard soil phosphorus tests. Plants and microbes can release organic anions to solubilize organic phosphorus from soil surfaces, and synthesize phosphatases to release inorganic phosphate from the solubilized compounds. We developed a procedure to estimate bioavailable organic phosphorus in tropical forest soils by simulating the secretion processes of organic acids and phosphatases. Five lowland tropical forest soils with contrasting properties (pH 4.4-6.1, total P 86-429 mg P kg(- 1)) were extracted with 2 mM citric acid (i.e., 10 μmol g(- 1), approximating rhizosphere concentrations) adjusted to soil pH in a 4:1 solution to soil ratio for 1 h. Three phosphatase enzymes were then added to the soil extract to determine the forms of hydrolysable organic phosphorus. Total phosphorus extracted by the procedure ranged between 3.22 and 8.06 mg P kg(- 1) (mean 5.55 ± 0.42 mg P kg(- 1)), of which on average three quarters was unreactive phosphorus (i.e., organic phosphorus plus inorganic polyphosphate). Of the enzyme-hydrolysable unreactive phosphorus, 28% was simple phosphomonoesters hydrolyzed by phosphomonoesterase from bovine intestinal mucosa, a further 18% was phosphodiesters hydrolyzed by a combination of nuclease from Penicillium citrinum and phosphomonoesterase, and the remaining 51% was hydrolyzed by a broad-spectrum phytase from wheat. We conclude that soil organic phosphorus can be solubilized and hydrolyzed by a combination of organic acids and phosphatase enzymes in lowland tropical forest soils, indicating that this pathway could make a significant contribution to biological phosphorus acquisition in tropical forests. Furthermore, we have developed a method that can be used to assess the bioavailability of this soil organic phosphorus.

  17. Investigation of non-halogenated solvent mixtures for high throughput fabrication of polymerfullerene solar cells

    NARCIS (Netherlands)

    Schmidt-Hansberg, B.; Sanyal, M.; Grossiord, N.; Galagan, Y.O.; Baunach, M.; Klein, M.F.G.; Colsmann, A.; Scharfer, P.; Lemmer, U.; Dosch, H.; Michels, J.J; Barrena, E.; Schabel, W.

    2012-01-01

    The rapidly increasing power conversion efficiencies of organic solar cells are an important prerequisite towards low cost photovoltaic fabricated in high throughput. In this work we suggest indane as a non-halogenated replacement for the commonly used halogenated solvent o-dichlorobenzene. Indane w

  18. Investigation of non-halogenated solvent mixtures for high throughput fabrication of polymerfullerene solar cells

    NARCIS (Netherlands)

    Schmidt-Hansberg, B.; Sanyal, M.; Grossiord, N.; Galagan, Y.O.; Baunach, M.; Klein, M.F.G.; Colsmann, A.; Scharfer, P.; Lemmer, U.; Dosch, H.; Michels, J.J; Barrena, E.; Schabel, W.

    2012-01-01

    The rapidly increasing power conversion efficiencies of organic solar cells are an important prerequisite towards low cost photovoltaic fabricated in high throughput. In this work we suggest indane as a non-halogenated replacement for the commonly used halogenated solvent o-dichlorobenzene. Indane w

  19. The physiological and ecological roles of volatile halogen production by marine diatoms

    Science.gov (United States)

    Hughes, Claire; Sun, Shuo

    2015-04-01

    Sea-to-air halogen flux is known to have a major impact on catalytic ozone cycling and aerosol formation in the troposphere. The biological production of volatile organic (e.g. bromoform, diiodomethane) and reactive inorganic halogens (e.g. molecular iodine) is believed to play an important role in mediating halogen emissions from the marine environment. Marine diatoms in particular are known to produce the organic and inorganic volatile halogens at high rates in pelagic waters and sea-ice systems. The climate-induced changes in diatom communities that have already been observed and are expected to occur throughout the world's oceans as warming progresses are likely to alter sea-to-air halogen flux. However, we currently have insufficient understanding of the physiological and ecological functions of volatile halogen production to develop modelling tools that can predict the nature and magnitude of the impact. The results of a series of laboratory studies aimed at establishing the physiological and ecological role of volatile halogen production in two marine polar diatoms (Thalassiosira antarctica and Porosira glacialis) will be described in this presentation. We will focus on our work investigating how the activity of the haloperoxidases, a group of enzymes known to be involved in halogenation reactions in marine organisms, is altered by environmental conditions. This will involve exploring the antioxidative defence role proposed for marine haloperoxidases by showing specifically how halogenating activity varies with photosynthetic rate and changes in the ambient light conditions in the two model marine diatoms. We will also present results from our experiments designed to investigate how volatile halogen production is impacted by and influences diatom-bacterial interactions. We will discuss how improved mechanistic understanding like this could pave the way for future volatile halogen-ecosystem model development.

  20. Affinity Solvents for Intensified Organics Extraction: Development Challenges and Prospects

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In most organics extraction processes, the commonly used solvents employ solely physical interactions. Therefore, for the recovery and purification of products from complex mixtures, the selectivity and/or capacity of classical solvents towards the desired solutes is usually insufficient, enforcing the need for complex and thus expensive separation schemes. Significant simplification and cost-reduction can be achieved when affinity solvents would be available that are able to recognize the solutes of interest by their molecular structure. The main development challenges to establish such affinity solvents are: Selection and incorporation of molecular recognition and complexation capabilities; Evaluation of extraction capabilities; Efficient recovery and recycling of the affinity solvents; Implementation in industrial extraction equipment. This paper presents how these development challenges are addressed at the University of Twente, going all the way from affinity solvent design and synthesis, via high throughput screening and characterization up to pilot plant evaluation. Essential in the successful development of affinity solvents are structural cooperations with molecular chemists and custom synthesis companies for their design and synthesis. The various aspects are illustrated by several examples where newly developed environmentally benign affinity solvents appeared able to create major breakthroughs. The applications addressed involve oxygenates, sugars, and pharmaceutical ingredients, such as optical isomers and biomolecules.

  1. The Halogen Occultation Experiment

    Science.gov (United States)

    Russell, James M., III; Gordley, Larry L.; Park, Jae H.; Drayson, S. R.; Hesketh, W. D.; Cicerone, Ralph J.; Tuck, Adrian F.; Frederick, John E.; Harries, John E.; Crutzen, Paul J.

    1993-01-01

    The Halogen Occultation Experiment (HALOE) uses solar occultation to measure vertical profiles of O3, HCl, HF, CH4, H2O, NO, NO2, aerosol extinction, and temperature versus pressure with an instantaneous vertical field of view of 1.6 km at the earth limb. Latitudinal coverage is from 80 deg S to 80 deg N over the course of 1 year and includes extensive observations of the Antarctic region during spring. The altitude range of the measurements extends from about 15 km to about 60-130 km, depending on channel. Experiment operations have been essentially flawless, and all performance criteria either meet or exceed specifications. Internal data consistency checks, comparisons with correlative measurements, and qualitative comparisons with 1985 atmospheric trace molecule spectroscopy (ATMOS) results are in good agreement. Examples of pressure versus latitude cross sections and a global orthographic projection for the September 21 to October 15, 1992, period show the utility of CH4, HF, and H2O as tracers, the occurrence of dehydration in the Antarctic lower stratosphere, the presence of the water vapor hygropause in the tropics, evidence of Antarctic air in the tropics, the influence of Hadley tropical upwelling, and the first global distribution of HCl, HF, and NO throughout the stratosphere. Nitric oxide measurements extend through the lower thermosphere.

  2. Treatment of phosphogypsum waste using suitable organic extractants.

    Science.gov (United States)

    El-Didamony, H; Ali, M M; Awwad, N S; Fawzy, M M; Attallah, M F

    Phosphogypsum (PG) is a residue of the phosphate fertilizer industry that has relatively high concentrations of harmful radioactive materials. The reduction in concentration of the radionuclides from PG was investigated. The removal process is based on leaching of radionuclides using suitable organic extractants. The studied radionuclides were (226)Ra, (210)Pb, (238)U and (40)K. The factors affect the leaching process such as type of leaching materials, contact time, concentration of the desired solvent, liquid to solid ratio, and temperature were studied. Based on the experimental results, about 71.1, 76.4, 62.4, and 75.7% of (226)Ra, (210)Pb, (238)U and (40)K respectively were successfully removed from the PG. The reduction in the concentration of radionuclides was accompanied by reduction in the concentration of rare earth elements (∑REE) equals to 69.8%. Using the desired organic extractant under optimum conditions for treatment of the PG waste leads to obtain a decontaminated product that can be safely used in many industrial applications.

  3. Structural perspective on enzymatic halogenation.

    Science.gov (United States)

    Blasiak, Leah C; Drennan, Catherine L

    2009-01-20

    Simple halogen substituents frequently afford key structural features that account for the potency and selectivity of natural products, including antibiotics and hormones. For example, when a single chlorine atom on the antibiotic vancomycin is replaced by hydrogen, the resulting antibacterial activity decreases by up to 70% ( Harris , C. M. ; Kannan , R. ; Kopecka , H. ; Harris , T. M. J. Am. Chem. Soc. 1985 , 107 , 6652 - 6658 ). This Account analyzes how structure underlies mechanism in halogenases, the molecular machines designed by nature to incorporate halogens into diverse substrates. Traditional synthetic methods of integrating halogens into complex molecules are often complicated by a lack of specificity and regioselectivity. Nature, however, has developed a variety of elegant mechanisms for halogenating specific substrates with both regio- and stereoselectivity. An improved understanding of the biological routes toward halogenation could lead to the development of novel synthetic methods for the creation of new compounds with enhanced functions. Already, researchers have co-opted a fluorinase from the microorganism Streptomyces cattleya to produce (18)F-labeled molecules for use in positron emission tomography (PET) ( Deng , H. ; Cobb , S. L. ; Gee , A. D. ; Lockhart , A. ; Martarello , L. ; McGlinchey , R. P. ; O'Hagan , D. ; Onega , M. Chem. Commun. 2006 , 652 - 654 ). Therefore, the discovery and characterization of naturally occurring enzymatic halogenation mechanisms has become an active area of research. The catalogue of known halogenating enzymes has expanded from the familiar haloperoxidases to include oxygen-dependent enzymes and fluorinases. Recently, the discovery of a nucleophilic halogenase that catalyzes chlorinations has expanded the repertoire of biological halogenation chemistry ( Dong , C. ; Huang , F. ; Deng , H. ; Schaffrath , C. ; Spencer , J. B. ; O'Hagan , D. ; Naismith , J. H. Nature 2004 , 427 , 561 - 565 ). Structural

  4. Halogenated compounds from marine algae.

    Science.gov (United States)

    Cabrita, Maria Teresa; Vale, Carlos; Rauter, Amélia Pilar

    2010-08-09

    Marine algae produce a cocktail of halogenated metabolites with potential commercial value. Structures exhibited by these compounds go from acyclic entities with a linear chain to complex polycyclic molecules. Their medical and pharmaceutical application has been investigated for a few decades, however other properties, such as antifouling, are not to be discarded. Many compounds were discovered in the last years, although the need for new drugs keeps this field open as many algal species are poorly screened. The ecological role of marine algal halogenated metabolites has somehow been overlooked. This new research field will provide valuable and novel insight into the marine ecosystem dynamics as well as a new approach to comprehending biodiversity. Furthermore, understanding interactions between halogenated compound production by algae and the environment, including anthropogenic or global climate changes, is a challenging target for the coming years. Research of halogenated metabolites has been more focused on macroalgae than on phytoplankton. However, phytoplankton could be a very promising material since it is the base of the marine food chain with quick adaptation to environmental changes, which undoubtedly has consequences on secondary metabolism. This paper reviews recent progress on this field and presents trends on the role of marine algae as producers of halogenated compounds.

  5. Thermochemical properties and phase behavior of halogenated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Fu, Jinxia; Suuberg, Eric M

    2012-03-01

    Knowledge of vapor pressure of organic pollutants is essential in predicting their fate and transport in the environment. In the present study, the vapor pressures of 12 halogenated polycyclic aromatic compounds (PACs), 9-chlorofluorene, 2,7-dichlorofluorene, 2-bromofluorene, 9-bromofluorene, 2,7-dibromofluorene, 2-bromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 9,10-dibromophenanthrene, 1-chloropyrene, 7-bromobenz[a]anthracene, and 6,12-dibromochrysene, were measured using the Knudsen effusion method over the temperature range of 301 to 464 K. Enthalpies and entropies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. The data were also compared with earlier published literature values to study the influence of halogen substitution on vapor pressure of PACs. As expected, the halogen substitution decreases vapor pressure compared with parent compounds but does not necessarily increase the enthalpy of sublimation. Furthermore, the decrease of vapor pressure also depends on the substitution position and the substituted halogen, and the di-substitution of chlorine and/or bromine decreases the vapor pressure compared with single halogen-substituted polycyclic aromatic hydrocarbons. In addition, the enthalpy of fusion and melting temperature of these 12 PACs were determined using differential scanning calorimetry and melting point analysis.

  6. Antibacterial activity of sequentially extracted organic solvent extracts of fruits, flowers and leaves of Lawsonia inermis L. from Jaffna.

    Science.gov (United States)

    Jeyaseelan, E Christy; Jenothiny, S; Pathmanathan, M K; Jeyadevan, J P

    2012-10-01

    To reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits, flowers and leaves of Lawsonia inermis (L. against) some pathogenic bacteria. Powders of fruits, flowers and leaves of L. inermis were continuously extracted with dichloromethane (DCM), ethyl acetate and ethanol at ambient temperature. The dried extracts were prepared into different concentrations and tested for antibacterial activity by agar well diffusion method, and also the extracts were tested to determine the available phytochemicals. Except DCM extract of flower all other test extracts revealed inhibitory effect on all tested bacteria and their inhibitory effect differed significantly (Peffect was showed by ethyl acetate extract of flower against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), and ethyl acetate extract of fruit on Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). The ethyl acetate and ethanol extracts of flower, fruit and leaf expressed inhibition even at 1 mg/100 µl against all test bacteria. Among the tested phytochemicals flavonoids were detected in all test extracts except DCM extract of flower. The study demonstrated that the ethyl acetate and ethanol extracts of fruit and flower of L. inermis are potentially better source of antibacterial agents compared to leaf extracts of respective solvents.

  7. Antibacterial activity of sequentially extracted organic solvent extracts of fruits, flowers and leaves of Lawsonia inermis L. from Jaffna

    Institute of Scientific and Technical Information of China (English)

    E Christy Jeyaseelan; S Jenothiny; MK Pathmanathan; JP Jeyadevan

    2012-01-01

    To reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits, flowers and leaves of Lawsonia inermis (L. against) some pathogenic bacteria. Methods: Powders of fruits, flowers and leaves of L. inermis were continuously extracted with dichloromethane (DCM), ethyl acetate and ethanol at ambient temperature. The dried extracts were prepared into different concentrations and tested for antibacterial activity by agar well diffusion method, and also the extracts were tested to determine the available phytochemicals.Results:Except DCM extract of flower all other test extracts revealed inhibitory effect on all tested bacteria and their inhibitory effect differed significantly (P<0.05). The highest inhibitory effect was showed by ethyl acetate extract of flower against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), and ethyl acetate extract of fruit on Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). The ethyl acetate and ethanol extracts of flower, fruit and leaf expressed inhibition even at 1 mg/ 100 μl against all test bacteria. Among the tested phytochemicals flavonoids were detected in all test extracts except DCM extract of flower.Conclusions:The study demonstrated that the ethyl acetate and ethanol extracts of fruit and flower of L. inermis are potentially better source of antibacterial agents compared to leaf extracts of respective solvents.

  8. Halogen radicals contribute to photooxidation in coastal and estuarine waters

    Science.gov (United States)

    Parker, Kimberly M.; Mitch, William A.

    2016-05-01

    Although halogen radicals are recognized to form as products of hydroxyl radical (•OH) scavenging by halides, their contribution to the phototransformation of marine organic compounds has received little attention. We demonstrate that, relative to freshwater conditions, seawater halides can increase photodegradation rates of domoic acid, a marine algal toxin, and dimethyl sulfide, a volatile precursor to cloud condensation nuclei, up to fivefold. Using synthetic seawater solutions, we show that the increased photodegradation is specific to dissolved organic matter (DOM) and halides, rather than other seawater salt constituents (e.g., carbonates) or photoactive species (e.g., iron and nitrate). Experiments in synthetic and natural coastal and estuarine water samples demonstrate that the halide-specific increase in photodegradation could be attributed to photochemically generated halogen radicals rather than other photoproduced reactive intermediates [e.g., excited-state triplet DOM (3DOM*), reactive oxygen species]. Computational kinetic modeling indicates that seawater halogen radical concentrations are two to three orders of magnitude greater than freshwater •OH concentrations and sufficient to account for the observed halide-specific increase in photodegradation. Dark •OH generation by gamma radiolysis demonstrates that halogen radical production via •OH scavenging by halides is insufficient to explain the observed effect. Using sensitizer models for DOM chromophores, we show that halogen radicals are formed predominantly by direct oxidation of Cl- and Br- by 3DOM*, an •OH-independent pathway. Our results indicate that halogen radicals significantly contribute to the phototransformation of algal products in coastal or estuarine surface waters.

  9. 40 CFR 721.8675 - Halogenated pyridines.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated pyridines. 721.8675... Substances § 721.8675 Halogenated pyridines. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated pyridine (PMN P-83-1163)...

  10. Instrument for Solvent Extraction and Analysis (ISEE) of Organics from Regolith Simulant Using Supercritical Fluid Extraction and Chromatography

    Science.gov (United States)

    Franco, Carolina; Hintze, Paul E.

    2017-01-01

    ISEE is an instrument with the potential to perform extractions from regolith found on the surface of asteroids and planets, followed by characterization and quantitation of the extracts using supercritical fluid extraction (SFE) and chromatography (SFC). SFE is a developed technique proven to extract a wide range of organic compounds. SFC is similar to High Performance Liquid Chromatography (HPLC) but has the advantage of performing chiral separations without needing to derivatize the chiral compounds. CO2 will be the solvent for both stages as it is readily available in the Mars atmosphere. ISEE will capture CO2 from the environment, and use it for SFE and SFC. If successful, this would allow ISEE to perform analysis of organic compounds without using consumables. This paper will present results on a preliminary, proof-of-principle effort to use SFE and SFC to extract and analyze lunar regolith simulant spiked with organic compounds representing a range of organics that ISEE would expect to characterize. An optimization of variables for the extraction of the organics from the spiked regolith was successfully developed, using 138 bar pressure and 40 C temperature. The extraction flow rate was optimized at 2% SLPM with 30% methanol modifier. The extractions were successful with a value of 77.3+/- 0.9% of organics extracted. However, the recovery of organics after the extraction was very low with only 48.5+/-14.2%. Moreover, three columns were selected to analyze multiple samples at a time; two of them are Viridis HSS C18 SB and Torus DIOL, and the third column, specific for chiral separations, has not yet been selected yet.

  11. Halogen behaviours during andesitic magma degassing: from magma chamber to volcanic plume

    Science.gov (United States)

    Balcone-Boissard, H.; Villemant, B.; Boudon, G.; Michel, A.

    2009-04-01

    Halogen (F, Cl, Br and I) behaviours during degassing of H2O-rich silicic magmas are investigated using volatile content analysis in glass (matrix glass and melt inclusions) of volcanic clasts (pumice and lava-dome fragments) in a series of plinian, vulcanian and lava dome-forming eruptions. Examples are taken from andesitic systems in subduction zones: Montagne Pelée and Soufrière Hills of Montserrat (Lesser Antilles) and Santa Maria-Santiaguito (Guatemala). Halogens behaviour during shallow degassing primarily depends on their incompatible character in melts and on H2O solubility. But variations in pre-eruptive conditions, degassing kinetics and syn-eruptive melt crystallisation, induce large variations in halogen extraction efficiency during H2O degassing, up to prevent halogen loss. In all studied systems, Cl, Br and I are not fractionated neither by differentiation nor by degassing processes: thus Cl/Br/I ratios remain well preserved in melts from reservoirs to eruption. These ratios measured in erupted clasts are characteristic of pre-eruptive magma compositions and may be used to trace deep magmatic processes. Moreover, during plinian eruptions, Cl, Br and I are extracted by H2O degassing but less efficiently than predicted by available experimental fluid-melt partition coefficients, by a factor as high as 5. F behaves as an incompatible element and, contrary to other halogens, is never significantly extracted by degassing. Degassing during lava dome-forming eruptions of andesitic magmas occurs mainly at equilibrium and is more efficient at extracting halogens and H2O than explosive degassing. The mobility of H2O and halogens depends on their speciation in both silicate melts and exsolved fluids which strongly varies with pressure. We suggest that the rapid pressure decrease during highly explosive eruptions prevents complete volatile speciation at equilibrium and consequently strongly limits halogen degassing.

  12. Organic light emitting diode with light extracting layer

    Science.gov (United States)

    Lu, Songwei

    2016-06-14

    A light extraction substrate includes a glass substrate having a first surface and a second surface. A light extraction layer is formed on at least one of the surfaces. The light extraction layer is a coating, such as a silicon-containing coating, incorporating nanoparticles.

  13. PARTICULARITIES OF ORGANIZING MANAGEMENT ACCOUNTING IN THE CASE OF COAL EXTRACTION UNITS

    National Research Council Canada - National Science Library

    DINA IONELA-CLAUDIA

    2013-01-01

    ..., the current paper aims at analyzing the manner of organizing managerial accountability at the level of the coal extraction societies staring from a succinct presentation of the particularities...

  14. An original data treatment for infrared spectra of organic matter, application to extracted soil organic matter

    Science.gov (United States)

    Gomes Rossin, Bruna; Redon, Roland; Raynaud, Michel; Nascimento, Nadia Regina; Mounier, Stéphane

    2017-04-01

    Infrared spectra of extracted organic matter are easy and rapid to do, but generally hard to interpreted over the presence or not of certain organic functions. Indeed, the organic matter is a complex mixture of molecules often having absorption overlapping and it is also difficult to have a well calibrated or normalised spectra due to the difficulty to have a well known solid content or homogeneity for a sample (Monakhova et al. 2015, Tadini et al. 2015, Bardy et al. 2008). In this work, the IRTF (InfraRed Fourier Transform) spectra were treated by an original algorithm developed to obtain the principal components of the IRTF spectra and their contributions for each sample. This bilinear decomposition used a PCA initialisation and the principal components were estimated from vectors calculated by PCA and linearly combined to provide non-negative signals minimizing a criterion based on cross-correlation. Hence, using this decomposition, it is possible to define IRTF signal of organic matter fractions like humic acid or fulvic acid depending on their origin like surface of depth of soil profiles. The method was used on a set of sample from Upper Negro River Basin (Amazon, Brazil) (Bueno,2009), where three soils sequences from surface to two meter depth containing 10 slices each. The sequences were sampled on a podzol well drain, a hydromorphic podzol and a cryptopodzol. From the IRTF data five representative component spectra were defined for all the extracted organic matter , and using other chemical composition information, a mechanism of organic matter fate is proposed to explain the observed results. Bardy, M., E. Fritsch, S. Derenne, T. Allard, N. R. do Nascimento, and G. T. Bueno. 2008. "Micromorphology and Spectroscopic Characteristics of Organic Matter in Waterlogged Podzols of the Upper Amazon Basin." Geoderma 145 (3-4): 222-30. Bueno, G.T. Appauvrissement et podzolisation des latérites du baissin du Rio Negro et gênese dês Podzols dans le haut bassin

  15. Chemical extraction of organic carbon to reduce the leaching potential risk from MSWI bottom ash.

    Science.gov (United States)

    Guimaraes, A L; Okuda, T; Nishijima, W; Okada, M

    2005-10-17

    The performance of extraction solvents, including organic and inorganic solvents, for organic carbon extraction from municipal solid waste incinerator (MSWI) bottom ash was evaluated. The total carbon (TC) extracted was used to ascertain the efficiency of extraction solvents and the reduction of dissolved organic carbon (DOC) leaching potential was used to evaluate the capacity of solvents to minimize environmental impacts of MSWI bottom ash over short- and long-term considerations in landfill sites. Extract final pH value was a prominent parameter affecting TC extraction. The higher efficiency was obtained at the lower extract final pH and acid or neutral condition was necessary to achieve approximately 30% of TC extraction from bottom ash. On the basis of the results of TC extraction, the efficiency of organic carbon reduction was evaluated using organic carbon leaching potential. Hydrochloric acid was the best solvent to extract organic carbon in controlled pH conditions. Hydrochloric acid reduced the organic carbon leaching potential of MSWI bottom ash by about 68% at neutral leaching pH.

  16. Organization of extracting molecules in organic phase: consequences on the extracting properties; Organisation des molecules extractantes en phase organique: consequences sur les proprietes extractantes

    Energy Technology Data Exchange (ETDEWEB)

    Meridiano, Y. [Paris-11 Univ., 91 - Orsay (France)]|[CEA Valrho, Lab de Chimie des Systemes Extractants (LCSE), 30 - Marcoule (France)

    2006-07-01

    The aim of this work is to establish a correlation between the organization of extracting molecules in organic phase and the implemented chemical equilibria. The first experimental data will be carried out on the chemical system of the DIAMEX process: DMDOHEMA/n-dodecane/HNO{sub 3}/H{sub 2}O/rare earth or actinide nitrate. Extraction isotherms will established in making the diamide concentration, the solute concentration, the acidity of the aqueous phase and the temperature vary. The different constituents will be titrated in organic and aqueous phases after extraction allowing thus to write an extraction equilibrium for each of the systems and to determine the bound constants. Then, a structural characterization of the organic phases will be considered in order to correlate the different organizations to the extraction constants, through several techniques as the surface tension measurements, the vapor pressure osmometry and the neutrons and X-rays small angle scattering which allow to characterize the size and geometry of the extractant aggregates as well as the interactions between them. (O.M.)

  17. Supercritical Carbon Dioxide Extraction of Organic Matter from Petroleum Source Rocks and Its Implications

    Institute of Scientific and Technical Information of China (English)

    沈忠民; 周光甲; 等

    1996-01-01

    Organic matter was experimentally extracted by supercritical fluids(CO2+1% isopropanol)from petroleum source rocks of different thermo-maturities at different buried depths in the same stratigraphic unit in the Dongying Basin.The results show that supercritical fluid extraction(SFE)is more effective than Soxhlet extraction(SE),with higher amounts and greater varieties of hydrocarbons and soluble organic matter becoming extractive.The supercritical CO2 extraction is therefore considered more valuable in evaluation of petroleum source rocks and oil resources,particularly those of immature types.

  18. A method for separating water soluble organics from a process stream by aqueous biphasic extraction

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, David J.; Mego, William A.

    1997-12-01

    The present invention relates to a method for separating water-miscible organic species from a process stream by aqueous biphasic extraction. In particular, the method includes extracting the organic species into a polymer-rich phase of an aqueous biphase system in which the process stream comprises the salt-rich phase, and, next, separating the polymer from the extracted organic species by contacting the loaded, polymer-rich phase with a water-immiscible organic phase. Alternatively, the polymer can be separated from the extracted organic species by raising the temperature of the loaded, polymer-rich phase above the cloud point, such that the polymer and the water-soluble organic species separate into two distinct aqueous phases. In either case, a substantially salt-free, concentrated aqueous solution containing the organic species is recovered.

  19. Expanded halogen-bonded anion organic networks with star-shaped iodoethynyl-substituted molecules: from corrugated 2D hexagonal lattices to pyrite-type 2-fold interpenetrated cubic lattices.

    Science.gov (United States)

    Lieffrig, Julien; Jeannin, Olivier; Fourmigué, Marc

    2013-04-24

    Halogen bonding interactions between halide anions and neutral polyiodinated linkers are used for the elaboration of anion organic frameworks, by analogy with well-known MOF derivatives. The extended, 3-fold symmetry, 1,3,5-tris(iodoethynyl)-2,4,6-trifluorobenzene (1) cocrystallizes with a variety of halide salts, namely, Et3S(+)I(-), Et3MeN(+)I(-), Et4N(+)Br(-), Et3BuN(+)Br(-), Me-DABCO(+)I(-), Bu3S(+)I(-), Bu4N(+)Br(-), Ph3S(+)Br(-), Ph4P(+)Br(-), and PPN(+)Br(-). Salts with 1:1 stoichiometry formulated as (1)·(C(+),X(-)) show recurrent formation of corrugated (6,3) networks, with the large cavities thus generated, filled either by the cations and solvent (CHCl3) molecules and/or by interpenetration (up to 4-fold interpenetration). The 2:1 salt formulated as (1)2·(Et3BuN(+)Br(-)) crystallizes in the cubic Ia3 space group (a = 22.573(5) Å, V = 11502(4) Å(3)), with the Br(-) ion located on 3 site and molecule 1 on a 3-fold axis. The 6-fold, unprecedented octahedral coordination of the bromide anion generates an hexagonal three-dimensional network of Pa3 symmetry, as observed in the pyrite model structure, at variance with the usual, but lower-symmetry, rutile-type topology. In this complex system, the I centering gives rise to a 2-fold interpenetration of class Ia, while the cations and solvent molecules are found disordered within interconnected cavities. Another related cubic structure of comparable unit cell volume (space group Pa3̅, a = 22.4310(15) Å, V = 11286.2(13) Å(3)) is found with (1)2·(Et3S(+)I(-)).

  20. Biological Activities of Aqueous and Organic Extracts from Tropical Marine Sponges

    Directory of Open Access Journals (Sweden)

    Tom Turk

    2010-04-01

    Full Text Available We report on screening tests of 66 extracts obtained from 35 marine sponge species from the Caribbean Sea (Curaçao and from eight species from the Great Barrier Reef (Lizard Island. Extracts were prepared in aqueous and organic solvents and were tested for hemolytic, hemagglutinating, antibacterial and anti-acetylcholinesterase (AChE activities, as well as their ability to inhibit or activate cell protein phosphatase 1 (PP1. The most interesting activities were obtained from extracts of Ircinia felix, Pandaros acanthifolium, Topsentia ophiraphidites, Verongula rigida and Neofibularia nolitangere. Aqueous and organic extracts of I. felix and V. rigida showed strong antibacterial activity. Topsentia aqueous and some organic extracts were strongly hemolytic, as were all organic extracts from I. felix. The strongest hemolytic activity was observed in aqueous extracts from P. acanthifolium. Organic extracts of N. nolitangere and I. felix inhibited PP1. The aqueous extract from Myrmekioderma styx possessed the strongest hemagglutinating activity, whilst AChE inhibiting activity was found only in a few sponges and was generally weak, except in the methanolic extract of T. ophiraphidites.

  1. [Halogenated natural products from the marine-derived actinobacteria and their halogenation mechanism].

    Science.gov (United States)

    Tan, Yi; Zhou, Hong-xia; Wang, Yi-guang; Gan, Mao-luo; Yang, Zhao-yong

    2013-09-01

    In the last decade, along with the development of taxonomy research in marine-derived actinobacteria, more and more halogenated natural products were discovered from marine actinobacteria. Most of them showed good biological activity and unique structure compared to those from land. The special halogenation mechanism in some compounds' biosynthesis has drawn great attention. So in this review, we focus on the halogenated natural products from marine actinobacteria and their halogenation mechanisms.

  2. Liquid-phase extraction coupled with metal-organic frameworks-based dispersive solid phase extraction of herbicides in peanuts.

    Science.gov (United States)

    Li, Na; Wang, Zhibing; Zhang, Liyuan; Nian, Li; Lei, Lei; Yang, Xiao; Zhang, Hanqi; Yu, Aimin

    2014-10-01

    Liquid-phase extraction coupled with metal-organic frameworks-based dispersive solid phase extraction was developed and applied to the extraction of pesticides in high fatty matrices. The herbicides were ultrasonically extracted from peanut using ethyl acetate as extraction solvent. The separation of the analytes from a large amount of co-extractive fat was achieved by dispersive solid-phase extraction using MIL-101(Cr) as sorbent. In this step, the analytes were adsorbed on MIL-101(Cr) and the fat remained in bulk. The herbicides were separated and determined by high-performance liquid chromatography. The experimental parameters, including type and volume of extraction solvent, ultrasonication time, volume of hexane and eluting solvent, amount of MIL-101(Cr) and dispersive solid phase extraction time, were optimized. The limits of detection for herbicides range from 0.98 to 1.9 μg/kg. The recoveries of the herbicides are in the range of 89.5-102.7% and relative standard deviations are equal or lower than 7.0%. The proposed method is simple, effective and suitable for treatment of the samples containing high content of fat.

  3. Halogens and their role in polar boundary-layer ozone depletion

    Directory of Open Access Journals (Sweden)

    W. R. Simpson

    2007-03-01

    Full Text Available During springtime in the polar regions, unique photochemistry converts inert halide salts ions (e.g. Br into reactive halogen species (e.g. Br atoms and BrO that deplete ozone in the boundary layer to near zero levels. Since their discovery in the late 1980s, research on ozone depletion events (ODEs has made great advances; however many key processes remain poorly understood. In this article we review the history, chemistry, dependence on environmental conditions, and impacts of ODEs. This research has shown the central role of bromine photochemistry, but how salts are transported from the ocean and are oxidized to become reactive halogen species in the air is still not fully understood. Halogens other than bromine (chlorine and iodine are also activated through incompletely understood mechanisms that are probably coupled to bromine chemistry. The main consequence of halogen activation is chemical destruction of ozone, which removes the primary precursor of atmospheric oxidation, and generation of reactive halogen atoms/oxides that become the primary oxidizing species. The different reactivity of halogens as compared to OH and ozone has broad impacts on atmospheric chemistry, including near complete removal and deposition of mercury, alteration of oxidation fates for organic gases, and export of bromine into the free troposphere. Recent changes in the climate of the Arctic and state of the Arctic sea ice cover are likely to have strong effects on halogen activation and ODEs; however, more research is needed to make meaningful predictions of these changes.

  4. In vitro antimicrobial potential of organic solvent extracts of novel ...

    African Journals Online (AJOL)

    SAM

    methanol and water extracts of selected promising actinomycetes strains were studied towards Gram- positive ... Streptomyces are used in the production of a diverse array of ..... n-hexane, chloroform, diethyl ether, ethyl acetate, butyl acetate ...

  5. Assessment of extraction methods with fowl manure for the production of liquid organic fertilizers.

    Science.gov (United States)

    Gross, A; Arusi, R; Fine, P; Nejidat, A

    2008-01-01

    Supplementary nitrogen (N) side-dressing via the irrigation system is needed in organic cropping. The aim here was to improve N-extraction efficiency, by testing five extraction protocols with guano, layer and broiler manures. The manure-N released by the different methods and manures was mainly in the form of ammonia and ranged from 50% to 85% with no differences among extraction methods. Volatilised ammonia from the extract solution was trapped. At the end of the extraction period, the pH of the extract solution was raised and the rest of the volatilised ammonia was trapped. In the case of guano, about 89% of the manure-N that was mineralised to the extract solution volatilised (after a pH increase), whereas in the layer and broiler manures, 59% and 54% were volatilised, respectively. Extraction of ammonia, its volatilisation and entrapment could provide a significantly more efficient N source than using the extract solution as currently recommended.

  6. Organization of extracting molecules of the diamide type: link with the extracting properties?; Organisation des molecules extractantes de type diamide: lien avec les proprietes extractantes?

    Energy Technology Data Exchange (ETDEWEB)

    Meridiano, Y.

    2009-02-15

    The aim of these studies is to establish a link between the different organizations of diamide extractants (used in the DIAMEX process) and their extracting properties. The effects of the key parameters leading the liquid-liquid extraction (concentration of extractant, nature of solute, activity of the aqueous phase, nature of the diluent and temperature) are studied: 1) at the supramolecular scale, with the characterization of the extractant organizations by vapor-pressure osmometry (VPO) and small angle neutron and X-ray scattering (SANS/SAXS) experiments; 2) at the molecular scale, with the quantification of the extracted solutes (water, nitric acid, metal nitrate) and the determination of extracted complexes stoichiometries by electro-spray mass spectrometry (ESI-MS) experiments. The DMDOHEMA molecule acts as a classical surfactant and forms aggregates of the reverse micelle type. Taking into account the established supramolecular diagrams, a quantitative link between the extractants structures and their extracting properties has been brought to light. To model the europium nitrate extraction, two approaches have been developed: - an approach based on mass action laws. Extractions equilibria have been proposed taking into account the supramolecular speciation; - an innovative approach considering the extracted ions as adsorbed on a specific surface of the extractant molecule which depends on the extractant organization state. The ion extraction can be considered as a sum of isotherms corresponding to the different states of organization. This approach allows to compare the extraction efficiency of an extracting molecule as a function of its organization state. (author)

  7. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    Energy Technology Data Exchange (ETDEWEB)

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  8. Solvent extraction of scandium from lateritic nickel- cobalt ores using different organic reagents

    Directory of Open Access Journals (Sweden)

    Ferizoğlu Ece

    2016-01-01

    Full Text Available Scandium is the most important and strategic metal that can be recovered as a by-product from lateritic nickel-cobalt ores. In this research, different extractants were investigated in order to extract scandium from a sulfate medium by a using a solvent extraction method. Generally, the organic extractants are classified as acidic, neutral and basic organophosphorus compounds. However, in solvent extraction of scandium, the acidic and neutral organophosphorus compounds are preferred due to their higher extraction efficiencies. Thus, the aim of the present study was to compare the scandium extraction efficiencies of some acidic and neutral organic reagents. For this reason, Ionquest 290 (Bis(2,4,4-trimethylpenthyl phosphonic acid, DEHPA (Di(2-ethylhexyl phosphoric acid, Cyanex 272 ((Bis(2,4,4-trimethylpentyl phosphinic acid which are acidic organophosphorus compounds, and Cyanex 923 (Trialkylphosphine oxide, which is a neutral organophosphorus compound, were used. The extraction capacities of these organics were studied with respect to the extractant concentration at same pH and phase ratio. As a result of the study, DEHPA was found to have higher scandium extraction efficiency with lower iron extraction at pH = 0.55 at a phase ratio of 10:1 = A:O.

  9. Halogenation generates effective modulators of amyloid-Beta aggregation and neurotoxicity.

    Directory of Open Access Journals (Sweden)

    H Edward Wong

    Full Text Available Halogenation of organic compounds plays diverse roles in biochemistry, including selective chemical modification of proteins and improved oral absorption/blood-brain barrier permeability of drug candidates. Moreover, halogenation of aromatic molecules greatly affects aromatic interaction-mediated self-assembly processes, including amyloid fibril formation. Perturbation of the aromatic interaction caused by halogenation of peptide building blocks is known to affect the morphology and other physical properties of the fibrillar structure. Consequently, in this article, we investigated the ability of halogenated ligands to modulate the self-assembly of amyloidogenic peptide/protein. As a model system, we chose amyloid-beta peptide (Aβ, which is implicated in Alzheimer's disease, and a novel modulator of Aβ aggregation, erythrosine B (ERB. Considering that four halogen atoms are attached to the xanthene benzoate group in ERB, we hypothesized that halogenation of the xanthene benzoate plays a critical role in modulating Aβ aggregation and cytotoxicity. Therefore, we evaluated the modulating capacities of four ERB analogs containing different types and numbers of halogen atoms as well as fluorescein as a negative control. We found that fluorescein is not an effective modulator of Aβ aggregation and cytotoxicity. However, halogenation of either the xanthenes or benzoate ring of fluorescein substantially enhanced the inhibitory capacity on Aβ aggregation. Such Aβ aggregation inhibition by ERB analogs except rose bengal correlated well to the inhibition of Aβ cytotoxicity. To our knowledge, this is the first report demonstrating that halogenation of aromatic rings substantially enhance inhibitory capacities of small molecules on Aβ-associated neurotoxicity via Aβ aggregation modulation.

  10. Effect of Alkaline-Stabilised Sewage Sludge on Extractable Organic Carbon and Copper in Soils

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An incubation experiment was conducted to evaluate the potential for water contamination with sludgederived organic substances and copper following land application of alkaline-stabilised sewage sludge. Two contrasting sludge-amended soils were studied. Both soils were previously treated with urban and rural alkaline biosolids separately at sludge application rates of 0, 30 and 120 t ha-1 fresh product. The air-dried soil/sludge mixtures were wetted with distilled water, maintained at 40 % of water-holding capacity and equilibrated for three weeks at 4 ℃ before extraction. Subsamples were extracted with either distilled water or 0.5 mol L-1 K2SO4 solution. The concentrations of organic C in the aqueous and chemical extracts were determined directly with a total organic carbon (TOC) analyser. The concentrations of Cu in the two extracts were also determined by atomic absorption spectrophotometry. The relationship between the two extractable organic C fractions was examined, together with that between extractable organic C concentration and extractable Cu concentration. Application of alkaline biosolids increased the concentrations of soil mobile organic substances and Cu. The results are discussed in terms of a possible increase in the potential for leaching of sludge-derived organics and Cu in the sludge-amended soils

  11. Selective extraction of isolated mitotic apparatus. Evidence that typical microtubule protein is extracted by organic mercurial.

    Science.gov (United States)

    Bibring, T; Baxandall, J

    1971-02-01

    Mitotic apparatus isolated from sea urchin eggs has been treated with meralluride sodium under conditions otherwise resembling those of its isolation. The treatment causes a selective morphological disappearance of microtubules while extracting a major protein fraction, probably consisting of two closely related proteins, which constitutes about 10% of mitotic apparatus protein. Extraction of other cell particulates under similar conditions yields much less of this protein. The extracted protein closely resembles outer doublet microtubule protein from sea urchin sperm tail in properties considered typical of microtubule proteins: precipitation by calcium ion and vinblastine, electrophoretic mobility in both acid and basic polyacrylamide gels, sedimentation coefficient, molecular weight, and, according to a preliminary determination, amino acid composition. An antiserum against a preparation of sperm tail outer doublet microtubules cross-reacts with the extract from mitotic apparatus. On the basis of these findings it appears that microtubule protein is selectively extracted from isolated mitotic apparatus by treatment with meralluride, and is a typical microtubule protein.

  12. Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.

    Science.gov (United States)

    Kumari, Chandrawati; Varughese, Bijo; Ramji, Siddarth; Kapoor, Seema

    2016-10-01

    Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis.

  13. Negative Halogen Ions for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Grisham, L.R.; Kwan, J.W.; Hahto, S.K.; Hahto, S.T.; Leung, K.N.; Westenskow, G.

    2006-01-01

    Over the past quarter century, advances in hydrogen negative ion sources have extended the usable range of hydrogen isotope neutral beams to energies suitable for large magnetically confined fusion devices. Recently, drawing upon this experience, negative halogen ions have been proposed as an alternative to positive ions for heavy ion fusion drivers in inertial confinement fusion, because electron accumulation would be prevented in negative ion beams, and if desired, the beams could be photo-detached to neutrals. This paper reports the results of an experiment comparing the current density and beam emittance of Cl+ and Cl- extracted from substantially ion-ion plasmas with that of Ar+ extracted from an ordinary electron-ion plasma, all using the same source, extractor, and emittance scanner. At similar discharge conditions, the Cl- current was typically 85 – 90% of the positive chlorine current, with an e-/ Cl- ratio as low as seven without grid magnets. The Cl- was as much as 76% of the Ar+ current from a discharge with the same RF drive. The minimum normalized beam emittance and inferred ion temperatures of Cl+, Cl-, and Ar+ were all similar, so the current density and optical quality of Cl- appear as suitable for heavy ion fusion driver applications as a positive noble gas ion of similar mass. Since F, I, and Br should all behave similarly in an ion source, they should also be suitable as driver beams.

  14. Supramolecular organization of organic phases for DIAMEX solvent extraction process; Organisation supramoleculaire des phases organiques de malonamides du procede d'extraction DIAMEX

    Energy Technology Data Exchange (ETDEWEB)

    Martinet, L

    2005-04-15

    In the frame of nuclear waste cycle, supramolecular organization of organic phases has been studied for DIAMEX solvent extraction process. A general methodology has been developed in order to determine surfactant properties of an extractant at high concentration. An illustration is given by a malonamide (DMDBTDMA) at 0.7 mol/L, in dodecane and contacted with water, at 23 deg C. The concentrations of monomers (0.3 mol/L) and aggregates (0.4 mol/L), c.m.c. (0.25 mol/L), aggregation number (4,4), aggregation constant (7.7) and finally aggregates interactions (U/kT = -1.6) are quantified. The method is based on simultaneous utilization of four experimental techniques (small X-ray and neutron scattering, vapour pressure osmometry and tensiometry) added to the model of Baxter. The structure of malonamide organic phase is depending on extractant concentration. (i) Below 0.2 mol/L, it is a quasi-molecular liquid fluid, extracting few amount of solutes. (ii) From 0.2 to 1 mol/L, it is a complex liquid fluid, containing small spherical aggregates of 5 extractant molecules in coexistence with monomers. This phase behaves like typical microemulsions with reverse micelles, through its stabilizing effect of penetrating oil and steric repulsion between extractants. (iii) Above 1 mol/L, the organic phase is able to extract huge amount of solutes. When HNO{sub 3} or Nd(NO{sub 3} ){sub 3} are extracted, a gel with a pseudo-lamellar structure is observed. With UO{sub 2} (NO{sub 3} ){sub 2} a solid crystal with a ratio DMDBTDMA/UO{sub 2} (NO{sub 3} ){sub 2} equal to 1/1 is characteristic of the organic phase. The 'third phase' due to attractive interactions between aggregates has exactly the same supramolecular structure than an 'unsplitted organic phase' of the same composition. Aggregates interactions are independent on the chemical affinity of the extractant for solutes. (author)

  15. Determination of persistent organic pollutants in solid environmental samples using accelerated solvent extraction and supercritical fluid extraction. Exhaustive extraction and sorption/desorption studies of PCBs

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerklund, E.

    1998-10-01

    Human activity is constantly causing environmental problems due to production and release of numerous chemicals. A group of compounds of special concern is persistent organic pollutants (POP). These toxic, lipophilic chemicals have a high chemical and biological stability, and tend to accumulate in the lipid phase of living organisms. A major sink for POPs are sediments, and consequently these are important for the distribution of POPs in the aquatic environment. Traditionally, determination of POPs relay on exhaustive extraction using liquid extraction techniques (e.g. Soxhlet extraction developed in the late 19th century) followed by gas chromatographic analysis. Since liquid-solid extraction normally requires large volumes of organic solvents in combination with long extraction times and extract clean-up, there has been an increasing demand for improved technology. This should result in reduced organic solvent consumption and sample preparation time, at the same time improving the environment and cutting costs for POP monitoring. In this thesis two modern techniques with capability of fulfilling at least one of these goals have been investigated: (1) Supercritical Fluid Extraction (SFE), and (2) Accelerated Solvent Extraction (ASE). Polychlorinated biphenyls (PCBs) were chosen as model compounds in all experiments performed on environmental matrices, since they cover a relatively large range of physiochemical parameters. Important parameters influencing the overall extraction efficiency in ASE and SFE, are discussed and illustrated for a large number of sediments. It was demonstrated that, by careful consideration of the experimental parameters, both techniques are capable of replacing old methods such as Soxhlet extraction. ASE is somewhat faster than SFE, but the extracts generated in SFE are much cleaner and can be analyzed without sample clean-up. Consequently the overall sample preparation time may be substantially lower using SFE. However, ASE is important

  16. Effect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review

    Science.gov (United States)

    Miazek, Krystian; Sulc, Radek; Jirout, Tomas; Aguedo, Mario; Goffin, Dorothee

    2017-01-01

    In this review, the effect of organic solvents on microalgae cultures from molecular to industrial scale is presented. Traditional organic solvents and solvents of new generation-ionic liquids (ILs), are considered. Alterations in microalgal cell metabolism and synthesis of target products (pigments, proteins, lipids), as a result of exposure to organic solvents, are summarized. Applications of organic solvents as a carbon source for microalgal growth and production of target molecules are discussed. Possible implementation of various industrial effluents containing organic solvents into microalgal cultivation media, is evaluated. The effect of organic solvents on extraction of target compounds from microalgae is also considered. Techniques for lipid and carotenoid extraction from viable microalgal biomass (milking methods) and dead microalgal biomass (classical methods) are depicted. Moreover, the economic survey of lipid and carotenoid extraction from microalgae biomass, by means of different techniques and solvents, is conducted. PMID:28677659

  17. Stereoselective Halogenation in Natural Product Synthesis.

    Science.gov (United States)

    Chung, Won-jin; Vanderwal, Christopher D

    2016-03-24

    At last count, nearly 5000 halogenated natural products have been discovered. In approximately half of these compounds, the carbon atom to which the halogen is bound is sp(3) -hybridized; therefore, there are an enormous number of natural products for which stereocontrolled halogenation must be a critical component of any synthesis strategy. In this Review, we critically discuss the methods and strategies used for stereoselective introduction of halogen atoms in the context of natural product synthesis. Using the successes of the past, we also attempt to identify gaps in our synthesis technology that would aid the synthesis of halogenated natural products, as well as existing methods that have not yet seen application in complex molecule synthesis. The chemistry described herein demonstrates yet again how natural products continue to provide the inspiration for critical advances in chemical synthesis.

  18. Selective Extraction Methods for Aluminium, Iron and Organic Carbon from Montane Volcanic Ash Soils

    Institute of Scientific and Technical Information of China (English)

    B. JANSEN; F. H. TONNEIJCK; J. M. VERSTRATEN

    2011-01-01

    Montane volcanic ash soils contain disproportionate amounts of soil organic carbon and thereby play an often underestimated role in the global carbon cycle.Given the central role of A1 and Fe in stabilizing organic matter in volcanic ash soils,we assessed various extraction methods of A1,Fe,and C fractions from montane volcanic ash soils in northern Ecuador,aiming at elucidating the role of A1 and Fe in stabilizing soil organic matter (SOM).We found extractions with cold sodium hydroxide,ammonium oxalate/oxalic acid,sodium pyrophosphate,and sodium tetraborate to be particularly useful.Combination of these methods yielded information about the role of the mineral phase in stabilizing organic matter and the differences in type and degree of complexation of organic matter with Al and Fe in the various horizons and soil profiles.Sodium tetraborate extraction proved the only soft extraction method that yielded simultaneous information about the Al,Fe,and C fractions extracted.It also appeared to differentiate between SOM fractions of different stability.The fractions of copper chloride- and potassium chloride-extractable A1 were useful in assessing the total reactive and toxic Al fractions,respectively.The classical subdivision of organic matter into humic acids,fulvic acids,and humin added little useful information.The use of fulvic acids as a proxy for mobile organic matter as done in several model-based approaches seems invalid in the soils studied.

  19. Influence of Halogen Substituents on the Catalytic Oxidation of 2,4,6-Halogenated Phenols by Fe(III-Tetrakis(p-hydroxyphenyl porphyrins and Potassium Monopersulfate

    Directory of Open Access Journals (Sweden)

    Seiya Nagao

    2011-12-01

    Full Text Available The influence of halogen substituents on the catalytic oxidation of 2,4,6-trihalogenated phenols (TrXPs by iron(III-porphyrin/KHSO5 catalytic systems was investigated. Iron(III-5,10,15,20-tetrakis(p-hydroxyphenylporphyrin (FeTHP and its supported variants were employed, where the supported catalysts were synthesized by introducing FeTHP into hydroquinone-derived humic acids via formaldehyde poly-condensation. F (TrFP, Cl (TrCP, Br (TrBP and I (TrIP were examined as halogen substituents for TrXPs. Although the supported catalysts significantly enhanced the degradation and dehalogenation of TrFP and TrCP, the oxidation of TrBP and TrIP was not enhanced, compared to the FeTHP catalytic system. These results indicate that the degree of oxidation of TrXPs is strongly dependent on the types of halogen substituent. The order of dehalogenation levels for halogen substituents in TrXPs was F > Cl > Br > I, consistent with their order of electronegativity. The electronegativity of a halogen substituent affects the nucleophilicity of the carbon to which it is attached. The levels of oxidation products in the reaction mixtures were analyzed by GC/MS after extraction with n-hexane. The most abundant dimer product from TrFP via 2,6-difluoroquinone is consistent with a scenario where TrXP, with a more electronegative halogen substituent, is readily oxidized, while less electronegative halogen substituents are oxidized less readily by iron(III-porphyrin/KHSO5 catalytic systems.

  20. Genotoxicity of organic extracts of house dust from Shanxi, China

    Energy Technology Data Exchange (ETDEWEB)

    Naufal, Z.; Zhou, G.D.; McDonald, T.; Li, Z.W.; Li, Z.; Donnelly, K.C. [Texas A& amp; M Health Science Center, College Station, TX (USA). School for Rural Public Health

    2007-07-01

    Indoor combustion of solid fuel such as coal may generate respirable particles containing polycyclic aromatic hydrocarbons (PAH) that may adhere to settled dust. Dust might therefore present a major source of PAH exposure in humans. This study evaluated the in vitro and in vivo genotoxicity of PAH mixtures extracted from house dust samples. Four dust samples (E1-4) were collected from houses in Shanxi, China, where coal is heavily used for heating and cooking. For comparison, a coal sample was also collected from one of the houses and included in the analyses. The samples were extracted with methylene chloride: acetone (95:5 v/v), dried, and redissolved in appropriate solvents for assessment in genotoxicity assays. Samples were evaluated for their ability to induce point mutations in bacteria and DNA adducts in vivo. DNA adduct levels were analyzed by nuclease P1-enhanced P-32-postlabeling. PAH were quantified using gas chromatography/mass spectrometry. Based on chemical analysis, sample E1 had the highest concentration by sampling area of benzo(a) pyrene (BaP) (181 {mu} g/m{sup 2}) and total PAH (10100 {mu} g/m{sup 2}). However, based on the microbial genotoxicity assay, sample E3, with the highest carcinogenic PAH/total PAH ratio (26%), produced the greatest number of revertants. In mice, administration of the extract of coal induced more adducts (9.81 adducts per 109 nucleotides) than dust extracts. The results of this study confirm the presence of genotoxic chemicals in residential dust. Inhalation of respirable particles containing similar mixtures of PAH represents a cancer risk for humans.

  1. Halogen Chemistry on Catalytic Surfaces.

    Science.gov (United States)

    Moser, Maximilian; Pérez-Ramírez, Javier

    2016-01-01

    Halogens are key building blocks for the manufacture of high-value products such as chemicals, plastics, and pharmaceuticals. The catalytic oxidation of HCl and HBr is an attractive route to recover chlorine and bromine in order to ensure the sustainability of the production processes. Very few materials withstand the high corrosiveness and the strong exothermicity of the reactions and among them RuO2 and CeO2-based catalysts have been successfully applied in HCl oxidation. The search for efficient systems for HBr oxidation was initiated by extrapolating the results of HCl oxidation based on the chemical similarity of these reactions. Interestingly, despite its inactivity in HCl oxidation, TiO2 was found to be an outstanding HBr oxidation catalyst, which highlighted that the latter reaction is more complex than previously assumed. Herein, we discuss the results of recent comparative studies of HCl and HBr oxidation on both rutile-type (RuO2, IrO2, and TiO2) and ceria-based catalysts using a combination of advanced experimental and theoretical methods to provide deeper molecular-level understanding of the reactions. This knowledge aids the design of the next-generation catalysts for halogen recycling.

  2. Chlorine dioxide as phenol and H2S scavenger - formation of halogenated phenols and subsequent environmental risk

    Energy Technology Data Exchange (ETDEWEB)

    Melbye, Alf G.; Faksness, Liv-Guri; Knudsen, Boerre Leif

    2006-03-15

    Formation of halogenated phenols as side products from treatment of produced water with aqueous chlorine dioxide has been investigated. The literature describes formation of halogenated hydrocarbons in effluent treatment using chlorine, hypochlorite and chlorine dioxide. A new chlorine dioxide product, originally intended as a H2S scavenger in the oil and gas industry, has been tested both as a phenol scavenger and H2S-scavenger for produced water applications. The concern about the possible formation of halogenated by-products initiated laboratory testing of chlorine dioxide as phenol and H2S scavenger for produced water applications. The tests also included synthetic matrixes containing phenols, and the tests show that halogenated phenols, mainly brominated species, are found in produced water after treatment with chlorine dioxide. Due to potential environmental risk from halogenated organic contaminants, the use of chlorine dioxide as phenol and H2S scavenger is not recommended. (Author)

  3. Disinfection of vegetable seed by treatment with essential oils, organic acids and plant extract

    NARCIS (Netherlands)

    Wolf, van der J.M.; Birnbaum, Y.E.; Zouwen, van der P.S.; Groot, S.P.C.

    2008-01-01

    Various essential oils, organic acids, Biosept, (grapefruit extract), Tillecur and extracts of stinging nettle and golden rod were tested for their antimicrobial properties in order to disinfect vegetable seed. In in vitro assays, thyme oil, oregano oil, cinnamon oil, clove oil and Biosept had the h

  4. SUPERCRITICAL FLUID EXTRACTION OF SEMI-VOLATILE ORGANIC COMPOUNDS FROM PARTICLES

    Science.gov (United States)

    A nitrogen oxide flux chamber was modified to measure the flux of semi-volatile organic compounds (SVOCs). Part of the modification involved the development of methods to extract SVOCs from polyurethane foam (PUF), sand, and soil. Breakthroughs and extraction efficiencies were ...

  5. A Novel Mechanism for Halogenated Quinone- Mediated and Metal-Independent Organic Fenton-Like Reaction%不依赖于过渡金属离子的卤代醌介导的新型有机类Fenton反应机理

    Institute of Scientific and Technical Information of China (English)

    朱本占; 任福荣; 夏海英; 邵杰

    2012-01-01

    卤代醌是许多卤芳香持久有机污染物的致癌代谢产物和饮用水消毒副产物.羟基自由基(OH)被公认为生物系统中最具活性的活性氧物种,能导致生物体内DNA等生物大分子的氧化损伤.目前,最被广泛接受的OH产生机理是过渡金属离子催化的Fenton反应.综合采用电子自旋共振二级自旋捕获和其他分析方法,发现四氯苯醌和其它卤代醌皆可通过不依赖于过渡金属离子的途径,显著促进氢过氧化物(H2O2或有机氢过氧化物)的分解而产生OH或烷氧自由基,并首次检测到一种新型的、以碳为中心的醌自由基.基于以上研究,提出一类不依赖于过渡金属离子的卤代醌介导的新型有机类Fenton反应机理.%Halogenated quinones are a class of carcinogenic metabolites of many halogenated persistent organic pollutants and new chlorination disinfection byproducts in drinking water. The hydroxyl radical ("OH) has been considered to be one of the most reactive oxygen species produced in biological systems. It has been shown that 'OH can cause oxidative damage to DNA and other macromolecuies. One of the most widely accepted mechanisms for OH production is through the transition metal-catalyzed Fenton reaction. Through the complementary application of electron spin resonance (ESR) secondary spin-trapping and other analytical methods, we found that tetrachloro-1,4-benzoquinone (TCBQ) and other halogenated quinones could markedly enhance the decomposition of hydroperoxides (H2O2 and organic hydroperoxides) and formation of "OH and alkoxyl radicals independent of transition metal ions. A novel carbon-centered quinone ketoxy radical was also detected and identified for the first time. Based on these data, we proposed a novel mechanism for metal-independent and halogenated quinone-mediated organic Fenton-like reaction.

  6. Gas chromatography-mass spectrometry analysis of various organic extracts ofMerremia borneensisfrom Sabah

    Institute of Scientific and Technical Information of China (English)

    M Amzad Hossain; Muhammad Dawood Shah; Mahyar Sakari

    2011-01-01

    Objective:To analyse the chemical composition of different extracts ofMerremia borneensis (M. borneensis) by gas chromatography-mass spectrometry (GC-MS).Methods: The dried leaves powder was extracted with methanol at room temperature by using Soxhlet extractor. Methanol crude extracts ofM. borneensis were extrastel with hexane, chloroform, ethyl acetate and butanol. Results: Qualitative analyses of various organic crude extracts showed that majority of these are flavonoids, terpeniods, alkaloids and glycosides. Most of the identified compounds by GC-MS are biologically important. Further theM. borneensisleaf possesses certain characteristics that can be ascribed to cultivation on a domestic plantation.Conclusions: The suitable extracts for respective compounds can be chosen on the basis of aboveGC-MS analysis. All the major compounds from different extracts are biologically active molecules. Thus the identification of a good number of compounds from various extractsM. borneensis might have some ecological significance.

  7. Absorption, Translocation and Metabolism of Halogenated Organic Pollutants (HOPs) in Plants:A Review%植物对卤代有机污染物吸收、迁移和代谢的研究进展

    Institute of Scientific and Technical Information of China (English)

    莫凌; 张云; 林彰文; 邢巧; 吴江平; 罗孝俊; 麦碧娴

    2015-01-01

    The environmental risks of halogenated organic pollutants (HOPs) have attracted considerable research interest due to their persistence, long range transport, bioaccumulation, and toxicity. Plants are important reservoirs of pollutants in environment and play key role in trapping and transferring airborne pollutants to terrestrial ecosystems. Research on the bioaccumulation, translocation, and transformation of HOPs in plant is critically important to understand the behavior, evaluate the potential risks to ecological system, and phytoremediation of HOPs. This review summarized the recent data on the absorption and bioaccumulation of HOPs in plants. The absorption and translocation behaviors of HOPs from the atmosphere, soil, and water to the plants, and the metabolism and transformation of HOPs in plants were also reviewed. The key factors affected the bioaccumulation, translocation, degradation and transformation of HOPs in plants were discussed. Results of research showed that the key factors affected the bioaccumulation of HOPs in plants were octanol-air partition coefficient (KOA) and octanol-water partition coefficient (Kow). The values of root concentration factors (RCFs) were higher when the values of log Kow of compounds ranged from 6 to 8. The lipid content in plants, physicochemical property of compounds, and environmental media were the important factors affected the translocation of HOPs in plants. Dehalogenation was the primary degradation pathway of HOPs in plants, and methoxylation and hydroxylation are two major transformation ways. The soil bacteria with the genes of dehalogenation reductase, nitrate reductase (NaR) and glutathione S-transferases (GST) could effectively promote degradation and metabolism of HOPs in plants. Although these studies have made some progress, the research on the bioaccumulation, translocation, degradation and transformation of HOPs in plants were still in their infancy. The mechanism of bioaccumulation, translocation

  8. Assessing estrogenic activity and reproductive toxicity of organic extracts in WWTP effluents.

    Science.gov (United States)

    Li, Bo; Cao, Jun; Xing, Chuanhong; Wang, Zhijin; Cui, Liuxin

    2015-03-01

    Trace level organic contaminants might not be completely removed from the municipal wastewater and the safety incurred by them had become a concern. These organic pollutants were extracted from water samples and detected by GC-MS. The estrogenic activity of the organic was tested using Yeast Estrogen Screen to detect the transcriptional activation of the estrogen receptor (ER) and immature mouse uterotrophic bioassays to study reproductive toxicity. The results of GC-MS demonstrated the organic extracts in the municipal wastewater and the WWTP effluents Included two major categories, benzenes and Phthalates. The estrogenic activity of organic extracts from the secondary effluent (SE) and tertiary effluent (TE) was below that of the raw wastewater (RW). Results of uterotrophic bioassay demonstrated that SE would bring some potential hazards on animals while TE was relatively safe. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Complexation of europium(III) by organic extracts from Callovo-Oxfordian argillites

    Energy Technology Data Exchange (ETDEWEB)

    Brevet, L.; Grasset, L.; Ambles, A. [Univ. de Poitiers, Synthese et Reactivi te des Substances Naturelles, CNRS UMR 6514, 86022 Poitiers (France); Reiller, P.; Claret, F.; Amekraz, B.; Moulin, C. [CEA, CE Saclay, CEA/DEN/DANS/DPC/SECR, Labo ratoire de Speciation des Radionucleides et des Molecules, F-91191 Gif-sur-Yvette (France)

    2007-06-15

    The complexation behaviour of organic extracts obtained after acid alteration of Callovo-Oxfordian argillites toward europium (III) is studied in time resolved laser induced spectrofluorimetry. The presence of fluoride ions in one extract, originated from the dissolution of remaining silicates in HCl/HF, precludes the correct study. Nevertheless, the dialysis of the extract at 500 Da permits to obtain a clearer evolution of the complexation pattern. The fluorescence spectrum and decay are strikingly different the ones obtained on alkaline degradation products of the Callovo-Oxfordian argillite, and resemble more to a small organic molecule pattern.

  10. Halogen Bonding in Hypervalent Iodine Compounds.

    Science.gov (United States)

    Catalano, Luca; Cavallo, Gabriella; Metrangolo, Pierangelo; Resnati, Giuseppe; Terraneo, Giancarlo

    Halogen bonds occur when electrophilic halogens (Lewis acids) attractively interact with donors of electron density (Lewis bases). This term is commonly used for interactions undertaken by monovalent halogen derivatives. The aim of this chapter is to show that the geometric features of the bonding pattern around iodine in its hypervalent derivatives justify the understanding of some of the longer bonds as halogen bonds. We suggest that interactions directionality in ionic and neutral λ(3)-iodane derivatives is evidence that the electron density distribution around iodine atoms is anisotropic, a region of most positive electrostatic potential exists on the extensions of the covalent bonds formed by iodine, and these positive caps affect, or even determine, the crystal packing of these derivatives. For instance, the short cation-anion contacts in ionic λ(3)-iodane and λ(5)-iodane derivatives fully match the halogen bond definition and geometrical prerequisites. The same holds for the short contacts the cation of ionic λ(3)-iodanes forms with lone-pair donors or the short contacts given by neutral λ(3)-iodanes with incoming nucleophiles. The longer and weaker bonds formed by iodine in hypervalent compounds are usually called secondary bondings and we propose that the term halogen bond can also be used. Compared to the term secondary bond, halogen bond may possibly be more descriptive of some bonding features, e.g., its directionality and the relationships between structure of interacting groups and interaction strength.

  11. Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn

    Directory of Open Access Journals (Sweden)

    Francisco D. Hernandez-Castillo

    2010-01-01

    Full Text Available Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter, water and ethanol against R. solani in order to determine the Inhibitory Concentration (IC50 of each extract. Results: The results showed that extracts of both L. graveolens and C. illinoensis obtained with lanolin and ethanol (200 and 3000 ppm of total tannins, respectively inhibited at 100% growth of R. solani. The IC50 for each extract was highly variable, low IC50 values were obtained with L. graveolens (4.50×101 and C. illinoensis (4.33×102 extract using lanolin and ethanol respectively. Tannins extraction was strongly dependent on plant species and in the solvent used. Conclusion: The alternative organic solvents lanolin and cocoa butter allowed the recovery of polyphenols compounds with antifungal activity against R. solani.

  12. Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Chu, Rosalie K.; Toyoda, Jason; Toli?, Nikola; Robinson, Errol W.; Pa?a-Toli?, Ljiljana; Hess, Nancy J.

    2017-03-31

    A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO2. The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition. In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H2O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl3) mixture, or acetonitrile (ACN) and CHCl3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample

  13. Does fluorine participate in halogen bonding?

    Science.gov (United States)

    Eskandari, Kiamars; Lesani, Mina

    2015-03-16

    When R is sufficiently electron withdrawing, the fluorine in the R-F molecules could interact with electron donors (e.g., ammonia) and form a noncovalent bond (F⋅⋅⋅N). Although these interactions are usually categorized as halogen bonding, our studies show that there are fundamental differences between these interactions and halogen bonds. Although the anisotropic distribution of electronic charge around a halogen is responsible for halogen bond formations, the electronic charge around the fluorine in these molecules is spherical. According to source function analysis, F is the sink of electron density at the F⋅⋅⋅N BCP, whereas other halogens are the source. In contrast to halogen bonds, the F⋅⋅⋅N interactions cannot be regarded as lump-hole interactions; there is no hole in the valence shell charge concentration (VSCC) of fluorine. Although the quadruple moment of Cl and Br is mainly responsible for the existence of σ-holes, it is negligibly small in the fluorine. Here, the atomic dipole moment of F plays a stabilizing role in the formation of F⋅⋅⋅N bonds. Interacting quantum atoms (IQA) analysis indicates that the interaction between halogen and nitrogen in the halogen bonds is attractive, whereas it is repulsive in the F⋅⋅⋅N interactions. Virial-based atomic energies show that the fluorine, in contrast to Cl and Br, stabilize upon complex formation. According to these differences, it seems that the F⋅⋅⋅N interactions should be referred to as "fluorine bond" instead of halogen bond.

  14. Halogen bond: a long overlooked interaction.

    Science.gov (United States)

    Cavallo, Gabriella; Metrangolo, Pierangelo; Pilati, Tullio; Resnati, Giuseppe; Terraneo, Giancarlo

    2015-01-01

    Because of their high electronegativity, halogen atoms are typically considered, in most of their derivatives, as sites of high electron density and it is commonly accepted that they can form attractive interactions by functioning as the electron donor site (nucleophilic site). This is the case when they work as hydrogen bond acceptor sites. However, the electron density in covalently bound halogens is anisotropically distributed. There is a region of higher electron density, accounting for the ability of halogens to function as electron donor sites in attractive interactions, and a region of lower electron density where the electrostatic potential is frequently positive (mainly in the heavier halogens). This latter region is responsible for the ability of halogen atoms to function as the electron-acceptor site (electrophilic site) in attractive interactions formed with a variety of lone pair-possessing atoms, anions, and π-systems. This ability is quite general and is shown by a wide diversity of halogenated compounds (e.g., organohalogen derivatives and dihalogens). According to the definition proposed by the International Union of Pure and Applied Chemistry, any attractive interactions wherein the halogen atom is the electrophile is named halogen bond (XB). In this chapter, it is discussed how the practice and the concept of XB developed and a brief history of the interaction is presented. Papers (either from the primary or secondary literature) which have reported major experimental findings in the field or which have given important theoretical contributions for the development of the concept are recollected in order to trace how a unifying and comprehensive categorization emerged encompassing all interactions wherein halogen atoms function as the electrophilic site.

  15. Relevance of a perchloric acid extraction scheme to determine mineral and organic phosphorus in swine slurry.

    Science.gov (United States)

    Daumer, Marie-Line; Béline, Fabrice; Spérandio, Mathieu; Morel, Christian

    2008-03-01

    To increase the phosphorus recycling potential from swine slurry, mineral phosphorus products which could be used as fertilizers should be obtained and new processes need to be investigated. A routine method is needed to better evaluate the dissolved and solid mineral phosphorus in swine slurry. Cold perchloric acid extraction method previously developed for wastewater or sludge analysis was adapted. Ionic chromatography was used to measure orthophosphate in extracts. Only one extraction step was needed to distinguish between mineral and organic phosphorus in slurry. Reproducibility of the method was high (less than 5% of variation on the measured fractions). Selectivity was assessed by adding several organic and mineral phosphorus sources in the slurry. Cold perchloric extraction followed by ionic chromatography was very selective in quantifying both the mineral and organic forms of phosphorus in swine slurry.

  16. Efficacy of antimicrobials extracted from organic pecan shell for inhibiting the growth of Listeria spp.

    Science.gov (United States)

    Babu, Dinesh; Crandall, Philip G; Johnson, Casey L; O'Bryan, Corliss A; Ricke, Steven C

    2013-12-01

    Growers and processors of USDA certified organic foods are in need of suitable organic antimicrobials. The purpose of the research reported here was to develop and test natural antimicrobials derived from an all-natural by-product, organic pecan shells. Unroasted and roasted organic pecan shells were subjected to solvent free extraction to produce antimicrobials that were tested against Listeria spp. and L. monocytogenes serotypes to determine the minimum inhibitory concentrations (MIC) of antimicrobials. The effectiveness of pecan shell extracts were further tested using a poultry skin model system and the growth inhibition of the Listeria cells adhered onto the skin model were quantified. The solvent free extracts of pecan shells inhibited Listeria strains at MICs as low as 0.38%. The antimicrobial effectiveness tests on a poultry skin model exhibited nearly a 2 log reduction of the inoculated cocktail mix of Listeria strains when extracts of pecan shell powder were used. The extracts also produced greater than a 4 log reduction of the indigenous spoilage bacteria on the chicken skin. Thus, the pecan shell extracts may prove to be very effective alternative antimicrobials against food pathogens and supplement the demand for effective natural antimicrobials for use in organic meat processing.

  17. Method for separating water soluble organics from a process stream by aqueous biphasic extraction

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, D.J.; Mego, W.A.

    1999-09-07

    A method for separating water-miscible organic species from a process stream by aqueous biphasic extraction is provided. An aqueous biphase system is generated by contacting a process stream comprised of water, salt, and organic species with an aqueous polymer solution. The organic species transfer from the salt-rich phase to the polymer-rich phase, and the phases are separated. Next, the polymer is recovered from the loaded polymer phase by selectively extracting the polymer into an organic phase at an elevated temperature, while the organic species remain in a substantially salt-free aqueous solution. Alternatively, the polymer is recovered from the loaded polymer by a temperature induced phase separation (cloud point extraction), whereby the polymer and the organic species separate into two distinct solutions. The method for separating water-miscible organic species is applicable to the treatment of industrial wastewater streams, including the extraction and recovery of complexed metal ions from salt solutions, organic contaminants from mineral processing streams, and colorants from spent dye baths.

  18. Method for separating water soluble organics from a process stream by aqueous biphasic extraction

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, David J. (Naperville, IL); Mego, William A. (Naperville, IL)

    1999-01-01

    A method for separating water-miscible organic species from a process stream by aqueous biphasic extraction is provided. An aqueous biphase system is generated by contacting a process stream comprised of water, salt, and organic species with an aqueous polymer solution. The organic species transfer from the salt-rich phase to the polymer-rich phase, and the phases are separated. Next, the polymer is recovered from the loaded polymer phase by selectively extracting the polymer into an organic phase at an elevated temperature, while the organic species remain in a substantially salt-free aqueous solution. Alternatively, the polymer is recovered from the loaded polymer by a temperature induced phase separation (cloud point extraction), whereby the polymer and the organic species separate into two distinct solutions. The method for separating water-miscible organic species is applicable to the treatment of industrial wastewater streams, including the extraction and recovery of complexed metal ions from salt solutions, organic contaminants from mineral processing streams, and colorants from spent dye baths.

  19. Extraction of soluble substances from organic solid municipal waste to increase methane production.

    Science.gov (United States)

    Campuzano, Rosalinda; González-Martínez, Simón

    2015-02-01

    This work deals with the analysis of the methane production from Mexico City's urban organic wastes after separating soluble from suspended substances. Water was used to extract soluble substances under three different water to waste ratios and after three extraction procedures. Methane production was measured at 35 °C during 21 days using a commercial methane potential testing device. Results indicate that volatile solids extraction increases with dilution rate to a maximum of 40% at 20 °C and to 43% at 93 °C. The extracts methane production increases with the dilution rate as a result of enhanced dissolved solids extraction. The combined (extract and bagasse) methane production reached, in 6 days, 66% of the total methane produced in 21 days. The highest methane production rates were measured during the first six days.

  20. NEMO: Extraction and normalization of organization names from PubMed affiliation strings

    CERN Document Server

    Jonnalagadda, Siddhartha

    2011-01-01

    We propose NEMO, a system for extracting organization names in the affiliation and normalizing them to a canonical organization name. Our parsing process involves multi-layered rule matching with multiple dictionaries. The system achieves more than 98% f-score in extracting organization names. Our process of normalization that involves clustering based on local sequence alignment metrics and local learning based on finding connected components. A high precision was also observed in normalization. NEMO is the missing link in associating each biomedical paper and its authors to an organization name in its canonical form and the Geopolitical location of the organization. This research could potentially help in analyzing large social networks of organizations for landscaping a particular topic, improving performance of author disambiguation, adding weak links in the co-author network of authors, augmenting NLM's MARS system for correcting errors in OCR output of affiliation field, and automatically indexing the P...

  1. Extraction methods for recovery of volatile organic compounds from fortified dry soils

    Energy Technology Data Exchange (ETDEWEB)

    Minnich, M.M.; Zimmerman, J.H. [Lockheed Martin Environmental Services, Las Vegas, NV (United States); Schumacher, B.A. [Environmental Protection Agency, Las Vegas, NV (United States)

    1996-09-01

    Recovery of 8 volatile organic compounds (VOCs) from dry soils, each fortified at 800 ng/g soil, was studied in relation to the extraction method and time of extraction. Extraction procedures studied on 2 desiccator-dried soils were modifications of EPA low- and high-level purge-and-trap extractions (SW-846 Method 5030A): treatment 1, unmodified low-level procedure; treatment 2, 18 h water presoak followed by low-level procedure; treatment 3, 24 h methanol extract at room temperature followed by high-level procedure; and treatment 4, 24 h methanol extract at 65{degrees}C followed by high-level procedure. VOC recoveries from replicate soil samples increased in the treatment order 1 through 4. With Charleston soil (8% clay and 3.8% organic carbon), highly significant differences (p {le} 0.001) in recoveries among treatments were observed for trichloroethene (TCE), tetrachloroethene (PCE), toluene, ethylbenzene, and o-xylene, with 2- to 3-fold increased recoveries between treatments 1 and 3. With Hayesville soil (32% clay and 0.2% organic carbon), significant improvements (p{le}0.05) in recoveries of toluene, ethylbenzene, o-oxylene, 1,1,1-trichloroethane, TCE, and PCE were observed for heated methanol (treatment 4) rather than water extraction (treatment 1), but the increases were less than 2-fold. 19 refs., 1 fig., 5 tabs.

  2. Informative document halogenated hydrocarbon-containing waste

    NARCIS (Netherlands)

    Verhagen H

    1992-01-01

    This "Informative document halogenated hydrocarbon-containing waste" forms part of a series of "Informative documents waste materials". These documents are conducted by RIVM on the instructions of the Directorate General for the Environment, Waste Materials Directorate, in behal

  3. Cross-reactivity of Halogenated Platinum Salts

    Science.gov (United States)

    Halogenated platinum (Pt) salts are well-known respiratory sensitizers associated with the development of asthma. People may be exposed to a variety of platinum compounds in different contexts (e.g. occupationally, automobile exhaust). Published reports suggest that sensitizati...

  4. Exciton transport, charge extraction, and loss mechanisms in organic photovoltaics

    Science.gov (United States)

    Scully, Shawn Ryan

    Organic photovoltaics have attracted significant interest over the last decade due to their promise as clean low-cost alternatives to large-scale electric power generation such as coal-fired power, natural gas, and nuclear power. Many believe power conversion efficiency targets of 10-15% must be reached before commercialization is possible. Consequently, understanding the loss mechanisms which currently limit efficiencies to 4-5% is crucial to identify paths to reach higher efficiencies. In this work, we investigate the dominant loss mechanisms in some of the leading organic photovoltaic architectures. In the first class of architectures, which include planar heterojunctions and bulk heterojunctions with large domains, efficiencies are primarily limited by the distance photogenerated excitations (excitons) can be transported (termed the exciton diffusion length) to a heterojunction where the excitons may dissociate. We will discuss how to properly measure the exciton diffusion length focusing on the effects of optical interference and of energy transfer when using fullerenes as quenching layers and show how this explains the variety of diffusion lengths reported for the same material. After understanding that disorder and defects limit exciton diffusion lengths, we suggest some approaches to overcome this. We then extensively investigate the use of long-range resonant energy transfer to increase exciton harvesting. Using simulations and experiments as support, we discuss how energy transfer can be engineered into architectures to increase the distance excitons can be harvested. In an experimental model system, DOW Red/PTPTB, we will show how the distance excitons are harvested can be increased by almost an order of magnitude up to 27 nm from a heterojunction and give design rules and extensions of this concept for future architectures. After understanding exciton harvesting limitations we will look at other losses that are present in planar heterojunctions. One of

  5. Quantitative extraction of organic tracer compounds from ambient particulate matter collected on polymer substrates.

    Science.gov (United States)

    Sun, Qinyue; Alexandrova, Olga A; Herckes, Pierre; Allen, Jonathan O

    2009-05-15

    Organic compounds in ambient particulate matter (PM) samples are used as tracers for PM source apportionment. These PM samples are collected using high volume samplers; one such sampler is an impactor in which polyurethane foam (PUF) and polypropylene foam (PPF) are used as the substrates. The polymer substrates have the advantage of limiting particle bounce artifacts during sampling; however these substrates may contain background organic additives. A protocol of two extractions with isopropanol followed by three extractions with dichloromethane (DCM) was developed for both substrate precleaning and analyte extraction. Some residual organic contaminants were present after precleaning; expressed as concentrations in a 24-h ambient PM sample, the residual amounts were 1 microg m(-3) for plasticizers and antioxidants, and 10 ng m(-3) for n-alkanes with carbon number lower than 26. The quantification limit for all other organic tracer compounds was approximately 0.1 ng m(-3) in a 24-h ambient PM sample. Recovery experiments were done using NIST Standard Reference Material (SRM) Urban Dust (1649a); the average recoveries for polycyclic aromatic hydrocarbons (PAHs) from PPF and PUF substrates were 117+/-8% and 107+/-11%, respectively. Replicate extractions were also done using the ambient samples collected in Nogales, Arizona. The relative differences between repeat analyses were less than 10% for 47 organic tracer compounds quantified. After the first extraction of ambient samples, less than 7% of organic tracer compounds remained in the extracted substrates. This method can be used to quantify a suite of semi- and non-polar organic tracer compounds suitable for source apportionment studies in 24-h ambient PM samples.

  6. Extraction of interesting organic compounds from olive oil waste

    Directory of Open Access Journals (Sweden)

    Jiménez, Ana

    2006-03-01

    Full Text Available In the olive fruits there is a large amount of bioactive compounds and substances of high interest. Many of them are known by owing health beneficial properties that contribute to protective effect of the virgin olive oil. During olive oil processing, most of them remain in the olive oil wastes. Although, olive-mill wastewater (OMWW or “alpechin”, olive oil cake (OOC, and the new by-product, known as “alperujo” in Spain and generated by the two-phase extraction process, represent a major disposal and potentially severe pollution problem for the industry, they are also promising source of substances of high value. This review summarises the last knowledge on the utilisation of residual products, with more than 90 references including articles and patents, which are promising with regard to future application. All these investigations have been classified into two options, the recovery of valuable natural constituents and the bioconversion into useful products.Existe una gran cantidad de compuestos bioactivos y de alto interés presentes en la aceituna. Muchos de ellos se conocen por las cualidades beneficiosas que aportan al aceite de oliva virgen. La mayoría permanecen en mayor cantidad en el subproducto de la extracción del aceite. Aunque, el alpechín, el orujo y el nuevo subproducto de extracción del aceite en dos fases, alperujo, representan un problema potencial de vertido y contaminación, también son una prometedora fuente de compuestos de alto valor. Esta revisión resume lo último que se conoce sobre la utilización de estos residuos en el campo anteriormente mencionado, con más de 90 referencias que incluyen artículos y patentes. Todas estas investigaciones han sido clasificadas en cuanto a la recuperación de constituyentes naturalmente presentes o en cuanto a la bioconversión de los residuos en sustancias de interés.

  7. Latest generation of halogen-containing pesticides.

    Science.gov (United States)

    Jeschke, Peter

    2017-02-01

    Agriculture is confronted with enormous challenges, from production of enough high-quality food to water use, environmental impacts and issues combined with a continually growing world population. Modern agricultural chemistry has to support farmers by providing innovative agrichemicals, used in applied agriculture. In this context, the introduction of halogen atoms into an active ingredient is still an important tool to modulate the properties of new crop protection compounds. Since 2010, around 96% of the launched products (herbicides, fungicides, insecticides/acaricides and nematicides) contain halogen atoms. The launched nematicides contain the largest number of halogen atoms, followed by insecticides/acaricides, herbicides and fungicides. In this context, fungicides and herbicides contain in most cases fluorine atoms, whereas nematicides and insecticides contain in most cases 'mixed' halogen atoms, for example chlorine and fluorine. This review gives an overview of the latest generation of halogen-containing pesticides launched over the past 6 years and describes current halogen-containing development candidates. © 2017 Society of Chemical Industry.

  8. Antiviral Activity of Natural Products Extracted from Marine Organisms

    Directory of Open Access Journals (Sweden)

    Sobia Tabassum

    2011-11-01

    Full Text Available Many epidemics have broken out over the centuries. Hundreds and thousands of humans have died over a disease. Available treatments for infectious diseases have always been limited. Some infections are more deadly than the others, especially viral pathogens. These pathogens have continuously resisted all kinds of medical treatment, due to a need for new treatments to be developed. Drugs are present in nature and are also synthesized in vitro and they help in combating diseases and restoring health. Synthesizing drugs is a hard and time consuming task, which requires a lot of man power and financial aid. However, the natural compounds are just lying around on the earth, may it be land or water. Over a thousand novel compounds isolated from marine organisms are used as antiviral agents. Others are being pharmacologically tested. Today, over forty antiviral compounds are present in the pharmacological market. Some of these compounds are undergoing clinical and pre-clinical stages. Marine compounds are paving the way for a new trend in modern medicine.

  9. Largescale Preparation of Organic-Dispersible Lanthanide Fluorides Nanocrystals via Colloid-Extraction Route

    Institute of Scientific and Technical Information of China (English)

    Zhao Weiwan; Zhang Shengmao; He Benfang; Wu Zhishen; Zhang Zhijun

    2007-01-01

    Organic-dispersible lanthanide fluorides nanocrystals were synthesized at a large Scale using colloid-extraction method, in the presence of dialkyl-dithiophosphinic acid (DDPA) as the extraction agent. The products were characterized by means of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transformation infrared (FTIR) spectroscopy. It was found that the synthesized lanthanide fluorides nanoparticles had high purity and crystallinity, and could be well dispersed in organic solvents such as chloroform, toluene etc., which could be closely related to the surface-capping of the nanocrystals by the DDPA molecules. Moreover, the nanocrystals before and after extraction by DDPA showed few differences in the microscopic morphologies. It was implied that DDPA as the extraction agent had good protection to the nanocrystals as well, which could be essential to the commercial application of the titled rare earth nanocrystals as novel multifunctional additives in the fields of lubrication.

  10. Molecularly imprinted polymers: New molecular recognition materials for selective solid-phase extraction of organic compounds

    OpenAIRE

    Martín Esteban, A.

    2001-01-01

    During the last few years molecularly imprinted polymers have appeared as new selective sorbents for solid-phase extraction of organic compounds in different samples. Molecular imprinting technology involves the preparation of a polymer with specific recognition sites for certain molecules. Once the polymer has been obtained, it can be used in solid-phase extraction protocols, where a careful selection of the most appropriate solvents to be used in the different steps (sample loading, washing...

  11. Selective extraction and separation of Fe, Mn oxides and organic materials in river surficial sediments

    Institute of Scientific and Technical Information of China (English)

    LI Feng-mei; WANG Xiao-li; LI Yu; GUO Shu-hai; ZHONG Ai-ping

    2006-01-01

    In order to investigate the adsorption mechanism of trace metals to surficial sediments (SSs), a selective extraction procedure was improved in the present work. The selective extraction procedure has been proved to selectively remove and separate Fe, Mn oxides and organic materials (OMs) in the non-residual fraction from the SSs collected in Songhua River, China. After screening different kinds of conventional extractants of Fe and Mn oxides and OMs used for separation of heavy metals in the soils respectively applied to selectively extract Mn oxides, Fe/Mn oxides and OMs. After the extraction treatments, the target components were removed with extraction efficiencies between 86.09%-93.36% for the hydroxylamine hydrochloride treatment, 80.63%-101.09% for the oxalate solution extraction, and 94.76%-102.83% for the hydrogen peroxide digestion, respectively. The results indicate that this selective extraction technology was effective for the extraction and separation of Fe, Mn oxides and OMs in the SSs,and important for further mechanism study of trace metal adsorption onto SSs.

  12. Membrane Dialysis Extraction (MDE): a novel approach for extracting toxicologically relevant hydrophobic organic compounds from soils and sediments for assessment in biotests

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, T.B.; Leist, E.; Braunbeck, T.; Hollert, H. [Dept. of Zoology, Aquatic Ecology and Toxicology, Univ. of Heidelberg (Germany); Rastall, A.C.; Erdinger, L. [Inst. of Hygiene and Medical Microbiology, Univ. of Heidelberg (Germany)

    2006-02-15

    Goal, scope and background. Organic solvents are routinely used to extract toxicants from polluted soils and sediments prior to chemical analysis or bioassay. Conventional extraction methods often require the use of heated organic solvents, in some cases under high pressure. These conditions can result in loss of volatile compounds from the sample and the degradation of thermally labile target analytes. Moreover, extracts of soils and sediments also frequently contain substantial quantities of organic macromolecules which can act as sorbing phases for target analytes and in doing so interfere with both chemical analysis and bioassays. Membrane dialysis extraction (MDE) is described as a simple, passive extraction method for selectively extracting toxicologically relevant hydrophobic organic compounds (HOCs) from polluted soils and sediments and analyzed for its applicability in ecotoxicological investigations. Methods. Toxicologically relevant hydrophobic organic compounds were extracted from wet and dry sediments by sealing replicate samples in individual lengths of pre-cleaned low-density polyethylene (LD-PE) tubing and then dialysing in n-hexane. Results. The membrane dialysis extraction was found to be at least as efficient as Soxhlet methodology to extract toxicologically relevant HOCs from sediment samples. In most cases, MDE-derived extracts showed a higher toxicological potential than the Soxhlet extracts. Lack of any significant effects in any MDE controls indicated these differences were not caused by contamination of the LD-PE membrane used. The elevated toxicological potential of MDE extracts is most likely the result of enhanced bioavailability of toxic compounds in consequence of lower amounts of organic macromolecules (i.e. sorbing phases) in the MDE extracts. This effect is probably the result of a size-selective restriction by the LD-PE membrane. Conclusion. Membrane dialysis extraction was found to be a simple, efficient and cost-effective method

  13. Potential for in situ chemical oxidation of acid extractable organics in oil sands process affected groundwater.

    Science.gov (United States)

    Sohrabi, V; Ross, M S; Martin, J W; Barker, J F

    2013-11-01

    The process of bitumen extraction from oil sands in Alberta, Canada leads to an accumulation of toxic acid-extractable organics (AEOs) in oil sands process water (OSPW). Infiltration of OSPW from tailings ponds and from their retaining sand dykes and subsequent transport towards surface water has occurred. Given the apparent lack of significant natural attenuation of AEOs in groundwater, remediation may be required. This laboratory study evaluates the potential use of unactivated persulfate and permanganate as in situ oxidation agents for remediation of AEOs in groundwater. Naphthenic acids (NAs; CnH2n+zO2), which are a component of the acutely toxic AEOs, were degraded by both oxidants in OSPW samples. Permanganate oxidation yielded some residual dissolved organic carbon (DOC) whereas persulfate mineralized the AEO compounds with less residual DOC. Acid-extractable organics from oxidized OSPW had essentially no Microtox toxicity.

  14. Extraction of Betulin, Trimyristin, Eugenol and Carnosic Acid Using Water-Organic Solvent Mixtures

    Directory of Open Access Journals (Sweden)

    Fulgentius N. Lugemwa

    2012-08-01

    Full Text Available A solvent system consisting of ethyl acetate, ethyl alcohol and water, in the volume ratio of 4.5:4.5:1, was developed and used to extract, at room temperature, betulin from white birch bark and antioxidants from spices (rosemary, thyme, sage, and oregano and white oak chips. In addition, under reflux conditions, trimyristin was extracted from nutmeg using the same solvent system, and eugenol from olives was extracted using a mixture of salt water and ethyl acetate. The protocol demonstrates the use of water in organic solvents to extract natural products from plants. Measurement of the free-radical scavenging activity using by 2,2-diphenyl-1-picrylhydrazyl (DPPH indicated that the extraction of plant material using ethyl acetate, ethyl alcohol and water (4.5:4.5:1, v/v/v was exhaustive when carried out at room temperature for 96 h.

  15. Focused ultrasound solid-liquid extraction for the determination of organic biomarkers in beachrocks.

    Science.gov (United States)

    Blanco-Zubiaguirre, L; Arrieta, N; Iturregui, A; Martinez-Arkarazo, I; Olivares, M; Castro, K; Olazabal, M A; Madariaga, J M

    2015-11-01

    Beachrocks are consolidated coastal sedimentary formations resulting mainly from the relative rapid cementation of beach sediments by different calcium carbonate polymorphs. Although previous works have already studied the elemental composition and the mineral phases composing these cements, few of them have focused their attention on the organic matter present therein. This work describes an extraction methodology based on focused ultrasound solid-liquid extraction (FUSLE), followed by analysis using large volume injection (LVI) in a programmable temperature vaporizer (PTV) combined with gas chromatography-mass spectrometry (GC-MS) in order to determine organics such as polycyclic aromatic hydrocarbons (PAHs) and biomarkers (hopanes), which can increase and confirm the information obtained so far. This goal has been achieved after the optimization of the main parameters affecting the extraction procedure, such as, extraction solvent, FUSLE variables (amplitude, extraction time and pulse time) and also variables affecting the LVI-PTV (vent time, injection speed and cryo-focusing temperature). The developed method rendered results comparable to traditional extraction methods in terms of accuracy (77-109%) and repeatability (RSD<23%). Finally, the analyses performed over real beachrock samples from the Bay of Biscay (Northern Spain) revealed the presence of the 16 EPA priority PAHs, as well as some organic biomarkers which could increase the knowledge about such beachrock formation.

  16. Charge extraction from nanostructured hybrid organic-inorganic photovoltaic cells

    Science.gov (United States)

    Goh, Chiatzun

    suppresses charge recombination across the TiO 2/P3HT interface. By controlling open circuit voltage, enhancing photocurrent and suppressing recombination through interface modification, the power efficiency of TiO2/P3HT device is almost doubled. Lastly, we demonstrate a novel imprinting method to nanostructure straight pores in TiO2, which can be infiltrated with conjugated polymers to make ordered inorganic-organic PV cells.

  17. Selective extraction of PAHs from a sediment with structural preservation of Natural Organic Matter.

    Science.gov (United States)

    Merdy, Patricia; Achard, Romain; Samaali, Ismahen; Lucas, Yves

    2014-07-01

    Selective extraction of Polycyclic Aromatic Hydrocarbons (PAH) without structural modification of the Natural Organic Matter (NOM) from a heavily contaminated sediment was investigated using various solvents mixtures. Structural modification of the NOM was monitored after extraction using 3D-fluorescence spectroscopy. Better results were obtained with a 15-h PAH extraction under reflux with a dichloromethane/cyclohexane 20/80 mixture. The experimental procedure was validated with NOM standard materials before to be applied on natural sediments. It could be applied to any environmental solid sample such as sediments and soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Anticomplement activity of organic solvent extracts from Korea local Amarantaceae spp.

    Science.gov (United States)

    Jung, Seil; Lee, Jai-Heon; Lee, Young-Choon; Moon, Hyung-In

    2012-04-01

    The study evaluated the anticomplement activity from various solvent extracts of nine Amarantaceae plants (Achyranthes japonica (Miq.) Nakai, Amaranthus mangostanus L., Amaranthus retroflexus L., Amaranthus spinosus L., Celosia argentea var. spicata., Amaranthus lividus L., Celosia cristata L., Amaranthus viridis L., Gomphrena globosa L.) from South Korea on the classical pathway. We have evaluated various organic solvent extract from nine Amarantaceae plants with regard to its anticomplement activity on the classical pathway. Achyranthes japonica chloroform extracts showed inhibitory activity against complement system with 50% inhibitory concentrations (IC(50)) value of 73.1μg/ml. This is the first report of anticomplement activity from Amarantaceae plants.

  19. Halogens, OVOC and H2O Distributions over the Eastern Pacific Ocean during TORERO

    Science.gov (United States)

    Dix, B. K.; Apel, E. C.; Baidar, S.; Zondlo, M. A.; Volkamer, R.

    2013-12-01

    As part of the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) field project 17 research flights were conducted with the NSF/NCAR GV aircraft over the Eastern Tropical Pacific Ocean (42S to 14N Lat.; 70W to 105W Long). Equipped with a combination of chemical in-situ sensors and remote sensing instruments, a broad spectrum of reactive halogen species, oxygenated hydrocarbons, and aerosols were measured over different ocean environments. Using optical remote sensing (airborne Multi Axis DOAS), we measured iodine monoxide (IO), bromine monoxide (BrO), glyoxal (CHOCHO) and water vapor among others. A newly developed parameterization method allowed us to directly convert the measured slant column densities into mixing ratios along the whole flight track. Atmospheric reactive halogen species and organic carbon are important, because they modify HOx radical abundances, influence the reactive chemistry and lifetime of climate active gases (e.g., ozone, methane, dimethyl sulfide), modify aerosol-cloud interactions and halogen radicals can also oxidize atmospheric mercury. Here we summarize and evaluate the spatial distribution of IO, BrO and glyoxal over the TORERO study area. For select case studies we present comparisons to halogen precursors and OVOCs measured in-situ by on-line mass spectrometry (trace organic gas analyzer). The correlation of remotely observed water vapor to in-situ measurements further allows us to conclude on the homogeneity of spatial scales covered by both remote and in-situ sensors.

  20. Effect of chickpea aqueous extracts, organic extracts, and protein concentrates on cell proliferation.

    Science.gov (United States)

    Girón-Calle, Julio; Vioque, Javier; del Mar Yust, María; Pedroche, Justo; Alaiz, Manuel; Millán, Francisco

    2004-01-01

    Pulses should be part of a healthy diet, and it is also becoming clear that they have health-promoting effects. Nevertheless, most studies on the bioactive or health-promoting properties of pulses have been carried out using soybeans. We have studied cell growth-regulating properties, which may be responsible for anti-cancer properties, in chickpea seeds. Chickpea seeds are a staple in the traditional diet of many Mediterranean, Asian, and South and Central American countries. In addition, chickpea seeds have industrial applications since they can be used for the preparation of protein concentrates and isolates. The cell lines Caco-2 (epithelial intestinal) and J774 (macrophages) have been exposed to chickpea seed extracts and protein preparations in order to screen the different chickpea fractions for effects on cell growth. Both cell growth-promoting and cell growth-inhibiting effects were found. Most interestingly, a fraction soluble in ethanol and acetone specifically and almost completely inhibited the growth of Caco-2 cells exhibiting a cancerous phenotype. It is concluded that chickpea seeds are a source of bioactive components and deserve further study for their possible anti-cancer effect.

  1. Evaluation of Genotoxic and Mutagenic Activity of Organic Extracts from Drinking Water Sources.

    Science.gov (United States)

    Guan, Ying; Wang, Xiaodong; Wong, Minghung; Sun, Guoping; An, Taicheng; Guo, Jun; Zhang, Guoxia

    2017-01-01

    An increasing number of industrial, agricultural and commercial chemicals in the aquatic environment lead to various deleterious effects on organisms, which is becoming a serious global health concern. In this study, the Ames test and SOS/umu test were conducted to investigate the potential genotoxicity and mutagenicity caused by organic extracts from drinking water sources. Organic content of source water was extracted with XAD-2 resin column and organic solvents. Four doses of the extract equivalent to 0.25, 0.5, 1 and 2L of source water were tested for toxicity. All the water samples were collected from six different locations in Guangdong province. The results of the Ames test and SOS/umu test showed that all the organic extracts from the water samples could induce different levels of DNA damage and mutagenic potentials at the dose of 2 L in the absence of S9 mix, which demonstrated the existence of genotoxicity and mutagenicity. Additionally, we found that Salmonella typhimurium strain TA98 was more sensitive for the mutagen. Correlation analysis between genotoxicity, Organochlorine Pesticides (OCPs) and Polycyclic Aromatic Hydrocarbons (PAHs) showed that most individual OCPs were frame shift toxicants in drinking water sources, and there was no correlation with total OCPs and PAHs.

  2. Quantity and nature of water-extractable organic matter from sandy loam soils with potato cropping managements

    Science.gov (United States)

    Water-extractable organic matter (WEOM) is part of the soil labile organic matter components. In this work, we evaluated the level and nature of soil WEOM from a long-term (6-year) potato crop rotation field experiment. The contents of water-extractable organic C (WEOC) were higher in continuous pot...

  3. Combining protein extraction and anaerobic digestion to produce feed, fuel and fertilizer from green biomass – An organic biorefinery concept

    DEFF Research Database (Denmark)

    Fernandez, Maria Santamaria; Salces, Beatriz Molinuevo; Lübeck, Mette

    Organically grown green biomass (red clover, clover grass) was investigated as a resource for organic feed and organic fertilizer by combination of proteins extraction and anaerobic digestion of the residues. Extraction of proteins from both crops revealed very favourable amino acid composition...

  4. Treatment System for Removing Halogenated Compounds from Contaminated Sources

    Science.gov (United States)

    Quinn, Jacqueline W. (Inventor); Clausen, Christian A. (Inventor); Yestrebsky, Cherie L. (Inventor)

    2015-01-01

    A treatment system and a method for removal of at least one halogenated compound, such as PCBs, found in contaminated systems are provided. The treatment system includes a polymer blanket for receiving at least one non-polar solvent. The halogenated compound permeates into or through a wall of the polymer blanket where it is solubilized with at least one non-polar solvent received by said polymer blanket forming a halogenated solvent mixture. This treatment system and method provides for the in situ removal of halogenated compounds from the contaminated system. In one embodiment, the halogenated solvent mixture is subjected to subsequent processes which destroy and/or degrade the halogenated compound.

  5. Overestimation of organic phosphorus in wetland soils by alkaline extraction and molybdate colorimetry.

    Science.gov (United States)

    Turner, Benjamin L; Newman, Susan; Reddy, K Ramesh

    2006-05-15

    Accurate information on the chemical nature of soil phosphorus is essential for understanding its bioavailability and fate in wetland ecosystems. Solution phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy was used to assess the conventional colorimetric procedure for phosphorus speciation in alkaline extracts of organic soils from the Florida Everglades. Molybdate colorimetry markedly overestimated organic phosphorus by between 30 and 54% compared to NMR spectroscopy. This was due in large part to the association of inorganic phosphate with organic matter, although the error was exacerbated in some samples by the presence of pyrophosphate, an inorganic polyphosphate that is not detected by colorimetry. The results have important implications for our understanding of phosphorus biogeochemistry in wetlands and suggest that alkaline extraction and solution 31p NMR spectroscopy is the only accurate method for quantifying organic phosphorus in wetland soils.

  6. Boiling of simulated tap water: effect on polar brominated disinfection byproducts, halogen speciation, and cytotoxicity.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Wagner, Elizabeth D; Osiol, Jennifer; Plewa, Michael J

    2014-01-01

    Tap water typically contains numerous halogenated disinfection byproducts (DBPs) as a result of disinfection, especially of chlorination. Among halogenated DBPs, brominated ones are generally significantly more toxic than their chlorinated analogues. In this study, with the aid of ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry by setting precursor ion scans of m/z 79/81, whole spectra of polar brominated DBPs in simulated tap water samples without and with boiling were revealed. Most polar brominated DBPs were thermally unstable and their levels were substantially reduced after boiling via decarboxylation or hydrolysis; the levels of a few aromatic brominated DBPs increased after boiling through decarboxylation of their precursors. A novel adsorption unit for volatile total organic halogen was designed, which enabled the evaluation of halogen speciation and mass balances in the simulated tap water samples during boiling. After boiling for 5 min, the overall level of brominated DBPs was reduced by 62.8%, of which 39.8% was volatilized and 23.0% was converted to bromide; the overall level of chlorinated DBPs was reduced by 61.1%, of which 44.4% was volatilized and 16.7% was converted to chloride; the overall level of halogenated DBPs was reduced by 62.3%. The simulated tap water sample without boiling was cytotoxic in a chronic (72 h) exposure to mammalian cells; this cytotoxicity was reduced by 76.9% after boiling for 5 min. The reduction in cytotoxicity corresponded with the reduction in overall halogenated DBPs. Thus, boiling of tap water can be regarded as a "detoxification" process and may reduce human exposure to halogenated DBPs through tap water ingestion.

  7. Phosphorus Speciation of Sequential Extracts of Organic Amendments using NMR Spectroscopy

    Science.gov (United States)

    Akinremi, O.

    2009-04-01

    O.O. 1Akinremi Babasola Ajiboye and Donald N. Flaten 1Department of Soil Science, University of Manitoba, Winnipeg, R3T 2NT, Canada We carried out this study in order to determine the forms of phosphorus in various organic amendments using state-of-the art spectroscopic technique. Anaerobically digested biosolids (BIO), hog (HOG), dairy (DAIRY), beef (BEEF) and poultry (POULTRY) manures were subjected to sequential extraction. The extracts were analyzed by solution 31P nuclear magnetic resonance (NMR) spectroscopy. Most of the total P analysed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) in the sequential extracts of organic amendments were orthophosphate, except POULTRY, which was dominated by organic P. The labile P fraction in all the organic amendments, excluding POULTRY, was mainly orthophosphate P from readily soluble calcium and some aluminum phosphates. In the poultry litter, however, Ca phytate was the main P species controlling P solubility. Such knowledge of the differences in the chemical forms of phosphorus in organic amendments are essential for proper management of these amendments for agro-environmental purposes Key words: organic amendments, solution NMR, sequential fractionation, labile phosphorus

  8. Highly sensitive electromembrane extraction for the determination of volatile organic compound metabolites in dried urine spot.

    Science.gov (United States)

    Suh, Joon Hyuk; Eom, Han Young; Kim, Unyong; Kim, Junghyun; Cho, Hyun-Deok; Kang, Wonjae; Kim, Da Som; Han, Sang Beom

    2015-10-16

    Electromembrane extraction coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for determination of ten volatile organic compound metabolites in dried urine spot samples. The dried urine spot approach is a convenient and economical sampling method, wherein urine is spotted onto a filter paper and dried. This method requires only a small amount of sample, but the analysis sometimes suffers from low sensitivity, which can lead to analytical problems in the detection of minor components in samples. The newly developed dried urine spot analysis using electromembrane extraction exhibited improved sensitivity and extraction, and enrichment of the sample was rapidly achieved in one step by applying an electric field. Aliquots of urine were spotted onto Bond Elut DMS cards and dried at room temperature. After drying, the punched out dried urine spot was eluted with water. Volatile organic compound metabolites were extracted from the sample through a supported liquid membrane into an alkaline acceptor solution inside the lumen of a hollow fiber with the help of an electric potential. The optimum extraction conditions were determined by using design of experiments (fractional factorial design and response surface methodology). Satisfactory sensitivity was achieved and the limits of quantification (LOQ) obtained were lower than the regulatory threshold limits. The method was validated by assessing the linearity, precision, accuracy, recovery, reproducibility, stability, and matrix effects. The results were acceptable, and the developed method was successfully applied to biological exposure monitoring of volatile organic compound metabolites in fifty human urine samples.

  9. Comparative study of hypoglycemic and antibacterial activity of organic extracts of four Bangladeshi plants

    Directory of Open Access Journals (Sweden)

    Mohammad Shah Hafez Kabir

    2016-03-01

    Full Text Available Objective: To examine hypoglycemic and antibacterial activity against some Gram-positive and Gram-negative bacteria of organic extracts of four Bangladeshi plants. Methods: An in vivo hypoglycemic effect on mice model was used to check the hypoglycemic effect of four Bangladeshi herbal organic extracts viz., roots of Curculigo recurvata W. T. Aiton (Satipata (C. recurvata, leaf of Amorphophallus bulbifer Roxb. (Olkachu (A. bulbifer, whole plant of Thunbergia grandiflora Roxb. (Nillata (T. grandiflora and leaf of Steudnera colocasiifolia K. Koch (Yunnan (S. colocasiifolia using glibenclamide as a positive control and water as a negative control. They were also tested for antibacterial activity on three Grampositive and four Gram-negative bacteria by disk diffusion method. C. recurvata, A. bulbifer and T. grandiflora were extracted with methanol and S. colocasiifolia was extracted with ethanol. Results: Among all the plant extract, only ethanol extract of S. colocasiifolia leaves at 800 mg/ kg dose significantly (P < 0.01 reduced fasting glucose level in normal mice as compared to standard drug glibenclamide (5 mg/kg. Ethanol extract of S. colocasiifolia leaves at 800 mg/ kg dose decreased 20.28% of blood glucose level after 2 h of administration in normal mice, where glibenclamide decreased 39.63%. Methanol extract of T. grandiflra didn’t show any zone of inhibition against the tested bacteria, but other three extracts showed a wide range of zone of inhibition. However, none of the extract showed antibacterial activity against all the tested bacteria. Methanol extract of C. recurvata showed maximum zone of inhibition against Bacillus cereus [(10.50 ± 0.50 mm], Salmonella typhi [(16.20 ± 1.26 mm], Escherichia coli [(13.00 ± 1.00 mm] and ethanol extract of S. colocasiifolia showed maximum zone of inhibition against Staphylococcus aureus [(11.20 ± 1.26 (mm], Bacillus subtilis [(12.00 ± 0.50 (mm], Salmonella paratyphi [(10.80 ± 0.29 (mm

  10. A QTAIM exploration of the competition between hydrogen and halogen bonding in halogenated 1-methyluracil: Water systems

    Science.gov (United States)

    Huan, Guo; Xu, Tianlv; Momen, Roya; Wang, Lingling; Ping, Yang; Kirk, Steven R.; Jenkins, Samantha; van Mourik, Tanja

    2016-10-01

    Using QTAIM we show that the hydrogen bonding complexes of 5-halogenated-1-methyluracil (XmU; X = F, Cl, Br, I or At) with a water molecule were always stronger than the corresponding halogen bonds. The strength of the hydrogen bond decreased with increasing halogen size. The hydrogen bonds displayed an admixture of covalent character but all the halogen bonds were purely electrostatic in nature. An F---O halogen bond was found and was facilitated by an intermediate F---H bonding interaction. The metallicity ξ(rb) of the C = O bonds neighboring the hydrogen bonds and of the C-X bonds contiguous with the halogen bonds was explored.

  11. Selective extraction of halogenated compounds from data measured by comprehensive multidimensional gas chromatography/high resolution time-of-flight mass spectrometry for non-target analysis of environmental and biological samples.

    Science.gov (United States)

    Hashimoto, Shunji; Zushi, Yasuyuki; Fushimi, Akihiro; Takazawa, Yoshikatsu; Tanabe, Kiyoshi; Shibata, Yasuyuki

    2013-03-22

    We developed a method that selectively extracts a subset from comprehensive 2D gas chromatography (GC×GC) and high-resolution time-of-flight mass spectrometry (HRTOFMS) data to detect and identify trace levels of organohalogens. The data were obtained by measuring several environmental and biological samples, namely fly ash, soil, sediment, the atmosphere, and human urine. For global analysis, some samples were measured without purification. By using our novel software, the mass spectra of organochlorines or organobromines were then extracted into a data subset under high mass accuracy conditions that were approximately equivalent to a mass resolution of 6000 for some samples. Mass defect filtering as pre-screening for the data extraction was very effective in removing the mass spectra of hydrocarbons. Those results showed that data obtained with HRTOFMS are valuable for global analysis of organohalogens, and probably of other compounds if specific data extraction methods can be devised.

  12. Removal of H2S and volatile organic sulfur compounds by silicone membrane extraction

    NARCIS (Netherlands)

    Manconi, I.; Lens, P.N.L.

    2009-01-01

    BACKGROUND: This study explores an alternative process for the abatement and/or desulfurization of H2S and volatile organic sulfur compounds (VOSC) containing waste streams, which employs a silicone-based membrane to simultaneously remove H2S and VOSC. An extractive membrane reactor allows the selec

  13. A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry

    Science.gov (United States)

    Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.

    2015-01-01

    A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…

  14. Antibacterial activity of sequentially extracted organic solvent extracts of fruits,flowers and leaves of Lawsonia inermis L.from Jaffna

    Institute of Scientific and Technical Information of China (English)

    E; Christy; Jeyaseelan; S; Jenothiny; MK; Pathmanathan; JP; Jeyadevan

    2012-01-01

    Objective:To reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits,flowers and leaves of Lawsonia inermis(L against)some pathogenic bacteria.Methods:Powders of fruits,flowers and leaves of L inermis were continuously extracted with dichloromethane(DCM),ethyl acetate and ethanol at ambient temperature.The dried extracts were prepared into different concentrations and tested for antibacterial activity by agar well diffusion method,and also the extracts were tested to detennine the available phytochemicals.Results:Except DCM extract of flower all other test extracts revealed inhibitory effect on all tested bacteria and their inhibitory effect differed significantly(P<0.05).The highest inhibitory effect was showed by ethyl acetate extract of flower against Staphylococcus aureus(S.aureus)and Pseudomonas aeruginosa(P.aeruginosa),and ethyl acetate extract of fruit on Escherichia coli(E.coli)and Bacillus subtilis(6.subtilis).The ethyl acetate and ethanol extracts of flower,fruit and leaf expressed inhibition even at 1 mg/100μl against all test bacteria.Among the tested phytochemicals flavonoids were detected in all test extracts except DCM extract of flower.Conclusions:The study demonstrated that the ethyl acetate and ethanol extracts of fruit and flower of L inermis are potentially better source of antibacterial agents compared to leaf extracts of respective solvents.

  15. Study of the Performance of the Organic Extracts of Chenopodium ambrosioides for Ag Nanoparticle Synthesis

    Directory of Open Access Journals (Sweden)

    Luis M. Carrillo-López

    2016-01-01

    Full Text Available There are many ways to obtain metal nanoparticles: biological, physical, and chemical ways and combinations of these approaches. Synthesis assisted with plant extracts has been widely documented. However, one issue that is under discussion refers to the metabolites responsible for reduction and stabilization that confine nanoparticle growth and prevent coalescence between nanoparticles in order to avoid agglomeration/precipitation. In this study, Ag nanoparticles were synthesized using organic extracts of Chenopodium ambrosioides with different polarities (hexane, dichloromethane, and methanol. Each extract was phytochemically characterized to identify the nature of the metabolites responsible for nanoparticle formation. With methanol extract, the compounds responsible for reducing and stabilizing silver nanoparticle were associated with the presence of phenolic compounds (flavonoids and tannins, while, with dichloromethane and hexane extracts, the responsible compounds were mainly terpenoids. Large part of the reducing activity of secondary metabolites in C. ambrosioides is closely related to compounds with antioxidant capacity, such as phenolic compounds (flavone glycoside and isorhamnetin, which are the main constituents of the methanol extracts. Otherwise, terpenoids (trans-diol, α-terpineol, monoterpene hydroperoxides, and apiole are the central metabolites present in dichloromethane and hexane extracts.

  16. Pyridinium ionic liquid-based liquid-solid extraction of inorganic and organic iodine from Laminaria.

    Science.gov (United States)

    Peng, Li-Qing; Yu, Wen-Yan; Xu, Jing-Jing; Cao, Jun

    2018-01-15

    A simple, green and effective extraction method, namely, pyridinium ionic liquid- (IL) based liquid-solid extraction (LSE), was first designed to extract the main inorganic and organic iodine compounds (I(-), monoiodo-tyrosine (MIT) and diiodo-tyrosine (DIT)). The optimal extraction conditions were as follows: ultrasonic intensity 100W, IL ([EPy]Br) concentration 200mM, extraction time 30min, liquid/solid ratio 10mL/g, and pH value 6.5. The morphologies of Laminaria were studied by scanning electron microscopy and transmission electron microscopy. The recovery values of I(-), MIT and DIT from Laminaria were in the range of 88% to 94%, and limits of detection were in the range of 59.40 to 283.6ng/g. The proposed method was applied to the extraction and determination of iodine compounds in three Laminaria. The results showed that IL-based LSE could be a promising method for rapid extraction of bioactive iodine from complex food matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A QSRR Study on the Relative Retention Time of Halogenated Methyl-phenyl Ethers

    Institute of Scientific and Technical Information of China (English)

    XU Hui-Ying; YU Qing-Sen; ZOU Jian-Wei; WANG Yan-Hua; WANG Hong-Qing; CHEN Xue-Song

    2006-01-01

    Halogenated methyl-phenyl ethers (anisoles) are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G* level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time (RRT) and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials (ESPs) together with the molecular volume (Vmc) could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.

  18. Seaonal Sea Ice as a source of organo-halogens during Polar night

    Science.gov (United States)

    Abrahamsson, Katarina; Granfors, Anna; Ahnoff, Martin

    2016-04-01

    The release of bromine from snow and sea ice surfaces has mainly been attributed to the reaction of hypobromous acid with bromide at acidic conditions to form Br2. Little attention has been given to the role of volatile halogenated organic compounds (organo-halogens) in the formation of reactive halogen species in the atmosphere during bromine explosion events. The load of organo-halogens was studied during a winter expedition to the Weddell Sea in June to August 2013. These compounds are emitted from the different compartments of the cryosphere to the atmosphere where they are photolysed to BrO and IO, which are involved in the degradation of ozone. We will present results that show the importance of organo-halogens formed during polar winter. In newly formed ice, in contrast to summer sea ice, the concentration of organo-bromine was found at levels as high as nM. These high concentrations were reflected both in frost flowers and in the sea-snow interface. Moreover, air measurements revealed high loads of organo-bromine over the sea ice. The situation was similar for iodinated compounds. Interestingly, the precursers of IO, mainly diiodomethane, could be measured in sea ice and snow, most probably due to the low light levels.

  19. Non-conventional gas phase remediation of volatile halogenated compounds by dehydrated bacteria.

    Science.gov (United States)

    Erable, Benjamin; Goubet, Isabelle; Seltana, Amira; Maugard, Thierry

    2009-06-01

    Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst. The hydrolysis of volatile halogenated substrates into the corresponding alcohol was studied in a solid/gas biofilter where lyophilised bacterial cultures were used as the catalyst. Four strains containing dehalogenase enzymes were tested for the hydrolysis of 1-chlorobutane. The highest removal yield was obtained using the dhaA-containing strains, the maximal reaction rate of 0.8 micromol min(-1)g(-1) being observed with Escherichia coli BL21(DE3)(dhaA). Various treatments such as cell disruption by lysozyme or alkaline gas addition in the bio-filter could stabilise the dehalogenase activity of the bacteria. A pre-treatment of the dehydrated bacterial cells by ammonia vapour improved the stability of the catalyst and a removal activity of 0.9 micromol min(-1)g(-1) was then obtained for 60h. Finally, the process was extended to a range of halogenated substrates including bromo- and chloro-substrates. It was shown that the removal capacity for long halogenated compounds (C(5)-C(6)) was greatly increased relative to traditional biological processes.

  20. [Anti-fungi activity of organic extracts from the tree Fagara monophylla (Rutaceae) in Venezuela].

    Science.gov (United States)

    Gómez, Yrma; Gil, Katiuska; González, Elba; Farías, Luz Marina

    2007-01-01

    The tree Fagara monophylla ranges throughout Tropical America. The genus Fagara has a diversity of alkaloid compounds with antibiotic properties; nevertheless, there are few reports antifungal activity of its organic compounds. Organic extracts from Venezuelan F. monophylla were tested for antimicrobial activity against Aspergillus terreus, A. flavus, Penicillium digitatum, P. funiculosum, P. citrinum, Paecilomyces and Candida albicans. Minimal Inhibitory Concentration (MIC) was determined. The susceptibility trials of organic fractions (Hex., CH2Cl2 and MeOH) showed that the highest inhibition was presented by MeOH against A. flavus (55 mm), P. digitatum (60 mm), P. funiculosum (56 mm) and C. albicans (26 mm). The activities of MeOH/EtOAc fractions 1 and 2 suggest a combined effect against A. flavus, P. digitatum and P. funiculosum. The MIC of 1 MeOH/ EtOAc subfraction activity was lower against C. albicans (32 microg/ml) and moderate (128 microg/ml) against P. digitatum. This organic extract has a great antifungal potential. The phytochemical proves and TLC testing on the organic extract, and the MeOH/EtOAc subfraction, respectively, indicated the presence of alkaloid compounds.

  1. Light extraction enhancement of organic light-emitting diodes using aluminum zinc oxide embedded anodes.

    Science.gov (United States)

    Hsu, Ching-Ming; Lin, Bo-Ting; Zeng, Yin-Xing; Lin, Wei-Ming; Wu, Wen-Tuan

    2014-12-15

    Aluminum zinc oxide (AZO) has been embedded onto indium tin oxide (ITO) anode to enhance the light extraction from an organic light-emitting diode (OLED). The embedded AZO provides deflection and scattering interfaces on the newly generated AZO/organics and AZO/ITO interfaces rather than the conventional ITO/organic interface. The current efficiency of AZO embedded OLEDs was enhanced by up to 64%, attributed to the improved light extraction by additionally created reflection and scattering of emitted light on the AZO/ITO interfaces which was roughed in AZO embedding process. The current efficiency was found to increase with the increasing AZO embedded area ratio, but limited by the accompanying increases in haze and electrical resistance of the AZO embedded ITO film.

  2. Evaluation of Halogenated Coumarins for Antimosquito Properties

    Directory of Open Access Journals (Sweden)

    Venugopala K. Narayanaswamy

    2014-01-01

    Full Text Available Mosquitoes are the major vectors of parasites and pathogens affecting humans and domestic animals. The widespread development of insecticide resistance and negative environmental effects of most synthetic compounds support an interest in finding and developing alternative products against mosquitoes. Natural coumarins and synthetic coumarin analogues are known for their several pharmacological properties, including being insecticidal. In the present study halogenated coumarins (3-mono/dibromo acetyl, 6-halogenated coumarin analogues were screened for larvicidal, adulticidal, and repellent properties against Anopheles arabiensis, a zoophilic mosquito that is one of the dominant vectors of malaria in Africa. Five compounds exerted 100% larval mortality within 24 h of exposure. All coumarins and halogenated coumarins reversibly knocked down adult mosquitoes but did not kill them after 24 h of exposure. Repellent properties could not be evidenced. Five compounds were considered potential larvicidal agents for further research and development, while adulticidal activity was considered only mild to moderate.

  3. New Route to Synthesize Surface Organometallic Complexes (SOMC): An Approach by Alkylating Halogenated Surface Organometallic Fragments

    KAUST Repository

    Hamieh, Ali Imad

    2017-02-01

    The aim of this thesis is to explore new simpler and efficient routes for the preparation of surface organometallic complexes (SOMC) for the transformation of small organic molecules to valuable products. The key element in this new route relies on surface alkylation of various halogenated surface coordination complexes or organometallic fragments (SOMF).

  4. Comparative study of hypoglycemic and antibacterial activity of organic extracts of four Bangladeshi plants

    Institute of Scientific and Technical Information of China (English)

    Mohammad Shah Hafez Kabir; Shabbir Ahmad; Md. Sofi Mahamoud; Nishan Chakrabarty; Md.Akramul Hoque; Mohammed Munawar Hossain; Md.Nazim Uddin Chy; Mohammed Shoibe

    2016-01-01

    Objective:To examine hypoglycemic and antibacterial activity against some Gram-positive and Gram-negative bacteria of organic extracts of four Bangladeshi plants. Methods:Anin vivo hypoglycemic effect on mice model was used to check the hypoglycemic effect of four Bangladeshi herbal organic extractsviz., roots ofCurculigo recurvata W. T. Aiton (Satipata) (C. recurvata), leaf ofAmorphophallus bulbiferRoxb. (Olkachu) (A. bulbifer), whole plant ofThunbergia grandiflora Roxb. (Nillata) (T. grandiflora) and leaf ofSteudnera colocasiifolia K. Koch (Yunnan) (S. colocasiifolia) using glibenclamide as a positive control and water as a negative control. They were also tested for antibacterial activity on three Gram-positive and four Gram-negative bacteria by disk diffusion method.C. recurvata,A. bulbifer andT. grandiflora were extracted with methanol andS. colocasiifolia was extracted with ethanol. Results:Among all the plant extract, only ethanol extract ofS. colocasiifolia leaves at 800 mg/kg dose significantly (P Conclusions: Through our study, it was found thatS. colocasiifolia could be considered as very promising and beneficial hypoglycemic agent. AlthoughC. recurvata andS. colocasiifolia showed comparable high antibacterial activity, further studies should be needed to develop new antibacterial agent from them.S. colocasiifolia may be a potential source for the development of new oral hypoglycemic agent.

  5. Study on preparation and application of novel saponification agent for organic phase of rare earths extraction

    Institute of Scientific and Technical Information of China (English)

    FENG Zongyu; HUANG Xiaowei; LIU Hongji; WANG Meng; LONG Zhiqi; YU Ying; WANG Chunmei

    2012-01-01

    In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation,the novel saponification agent of organic phase,which is magnesium bicarbonate solution,was prepared with the natural rich and cheap dolomite as mw material through carbonation process.The behavior and purification of main impurities ions in the carbonation process as well as the application effect of the novel saponification agent in the extraction and separation was researched.The results showed that the concentration of Fe,Al,Si impurities ions was.less than 5 ppm in the saponification agent through the development of effective removal technology,respectively.When the novel saponification agent was used in the extraction and separation,magnesium utilization rote was more than 95%,and rare earths extraction rate above 99.5% has achieved.Therefore,the technology could replace ammonia-water to saponify the organic phase in rare earth extraction and separation process.

  6. Microwave-assisted organic acid extraction of lignin from bamboo: structure and antioxidant activity investigation.

    Science.gov (United States)

    Li, Ming-Fei; Sun, Shao-Ni; Xu, Feng; Sun, Run-Cang

    2012-10-01

    Microwave-assisted extraction in organic acid aqueous solution (formic acid/acetic acid/water, 3/5/2, v/v/v) was applied to isolate lignin from bamboo. Additionally, the structural features of the extracted lignins were thoroughly investigated in terms of C₉ formula, molecular weight distribution, FT-IR, (1)H NMR and HSQC spectroscopy. It was found that with an increase in the severity of microwave-assisted extraction, there was an increase of phenolic hydroxyl content in the lignin. In addition, an increase of the severity resulted in a decrease of the bound carbohydrate content as well as molecular weight of the lignin. Antioxidant activity investigation indicated that the radical scavenging index of the extracted lignins (0.35-1.15) was higher than that of BHT (0.29) but lower than that of BHA (3.85). The results suggested that microwave-assisted organic acid extraction provides a promising way to prepare lignin from bamboo with good antioxidant activity for potential application in the food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Complex-forming organic ligands in cloud-point extraction of metal ions: a review.

    Science.gov (United States)

    Pytlakowska, K; Kozik, V; Dabioch, M

    2013-06-15

    Cloud-point extraction (CPE), an easy, safe, environmentally friendly, rapid and inexpensive methodology for preconcentration and separation of trace metals from aqueous solutions has recently become an attractive area of research and an alternative to liquid-liquid extraction. Moreover, it provides results comparable to those obtained with other separation techniques and has a greater potential to be explored in improving detection limits and other analytical characteristics over other methods. A few reviews have been published covering different aspects of the CPE procedure and its relevant applications, such as the phenomenon of clouding, the application in the extraction of trace inorganic and organic materials, as well as pesticides and protein substrates from different sources, or incorporation of CPE into an FIA system. This review focuses on general properties of the most frequently used organic ligands in cloud-point extraction and on literature data (from 2000 to 2012) concerning the use of modern techniques in determination of metal ions' content in various materials. The article is divided according to the class of organic ligands to be used in CPE.

  8. Organic extraction of bone lysates improves DNA purification with silica beads.

    Science.gov (United States)

    Desmyter, Stijn; De Cock, Greet; Moulin, Sabine; Noël, Fabrice

    2017-04-01

    In our standard protocol for DNA extraction from skeletal remains of unidentified bodies, bone lysates resulting from decalcification and Proteinase K treatment were purified with the DNA IQ™ Casework Pro Kit for Maxwell(®)16 automate (Promega, WI). Despite its success in the majority of cases, the DNA purification with paramagnetic silica beads failed in some challenging samples. This failure in DNA recovery was often associated with filter clogging during the required volume reduction of the lysate to enable loading on the automate. Two modifications to the standard method were tested for a more efficient filtering and purification. Adding collagenase to the lysate reduced the filter lead time but did not enhance DNA yield, while organic extraction of the crude lysate solved the filter clogging and resulted in successful DNA purification. The modified method in which a phenol treated lysate was loaded on the automate resulted in successful STR-profiling of the skeletal remains of all 13 unidentified bodies tested, which showed a wide variety in post mortem interval and preservation conditions. The variation in DNA yield between the 28 samples tested showed the importance of bone type selection and multiple sampling in successful STR-profiling of skeletal remains. Despite the disadvantages inherent to phenol, the organic extraction of crude bone lysates enhanced the efficiency of DNA purification with paramagnetic silica beads. The combined method of organic extraction and purification with silica beads resulted in STR-profiling of challenging bone samples.

  9. Halogen Chemistry in Volcanic Plumes (Invited)

    Science.gov (United States)

    Roberts, Tjarda

    2017-04-01

    Volcanoes release vast amounts of gases and particles in the atmosphere. Volcanic halogens (HF, HCl, HBr, HI) are co-emitted alongside SO2, and observations show rapid formation of BrO and OClO in the plume as it disperses into the troposphere. The development of 1D and Box models (e.g. PlumeChem) that simulate volcanic plume halogen chemistry aims to characterise how volcanic reactive halogens form and quantify their atmospheric impacts. Following recent advances, these models can broadly reproduce the observed downwind BrO/SO2 ratios using "bromine-explosion" chemistry schemes, provided they use a "high-temperature initialisation" to inject radicals (OH, Cl, Br and possibly NOx) which "kick-start" the low-temperature chemistry cycles that convert HBr into reactive bromine (initially as Br2). The modelled rise in BrO/SO2 and subsequent plateau/decline as the plume disperses downwind reflects cycling between reactive bromine, particularly Br-BrO, and BrO-HOBr-BrONO2. BrCl is produced when aerosol becomes HBr-depleted. Recent model simulations suggest this mechanism for reactive chlorine formation can broadly account for OClO/SO2 reported at Mt Etna. Predicted impacts of volcanic reactive halogen chemistry include the formation of HNO3 from NOx and depletion of ozone. This concurs with HNO3 widely reported in volcanic plumes (although the source of NOx remains under question), as well as observations of ozone depletion reported in plumes from several volcanoes (Mt Redoubt, Mt Etna, Eyjafjallajokull). The plume chemistry can transform mercury into more easily deposited and potentially toxic forms, for which observations are limited. Recent incorporation of volcanic halogen chemistry in a 3D regional model of degassing from Ambrym (Vanuatu) also predicts how halogen chemistry causes depletion of OH to lengthen the SO2 lifetime, and highlights the potential for halogen transport from the troposphere to the stratosphere. However, the model parameter-space is vast and

  10. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated benzyl ester acrylate... Specific Chemical Substances § 721.329 Halogenated benzyl ester acrylate (generic). (a) Chemical substance... halogenated benzyl ester acrylate (PMN P-90-1527) is subject to reporting under this section for...

  11. 40 CFR 721.535 - Halogenated alkane (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated alkane (generic). 721.535... Substances § 721.535 Halogenated alkane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated alkane (PMN P-01-433) is...

  12. 40 CFR 721.536 - Halogenated phenyl alkane.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated phenyl alkane. 721.536... Substances § 721.536 Halogenated phenyl alkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated phenyl alkane (PMN P-89-867)...

  13. 40 CFR 721.8700 - Halogenated alkyl pyridine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated alkyl pyridine. 721.8700... Substances § 721.8700 Halogenated alkyl pyridine. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated alkyl pyridine (PMN P-83-237)...

  14. GC/MS Analysis of Organic Compounds in Hot Water-Extractable Fraction from Shenfu Coal

    Institute of Scientific and Technical Information of China (English)

    LI Bao-min; YUAN Cheng; ZONG Zhi-min; CAO Jing-pei; LIU Guang-feng; WEI Xian-yong

    2007-01-01

    Shenfu Coal was extracted with hot pure water and slurry was isolated. The concentrated benzene-soluble fraction (CBSF) was analyzed with GC/MS and four types of organic compounds (OCs) were detected: HACOCs, DTEs, DMDT and LCAs. The amount of benzyl benzoate which is the most abundant OC was calculated by an internal standard method with an indicated amount of BP. The broken hydrogen bonds and ether bonds were responsible for the extraction of OCs from the coal .DTEs, DMDT and LCAs are essentially insoluble in water, whereas they are soluble, probably owing to intermolecular interaction of OCs with HACOCs.

  15. Biodegradability of soil water soluble organic carbon extracted from seven different soils

    Institute of Scientific and Technical Information of China (English)

    SCAGLIA Barbara; ADANI Fabrizio

    2009-01-01

    Water soluble organic carbon (WSOC) is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WSOC extracted from 7 soils differently managed. WSOC was extracted from soil with water (soil/water ratio of 1:2, W/V) for 30 min, and then tested for biodegradability by a liquid state respirometric test. Result obtained confirmed the finding that WSOC biodegradability depended on both land use and management practice. These results suggested the biodegradability test as suitable method to characterize WSOC, adding useful information to soil fertility.

  16. Effect of organic amendments and compost extracts on tomato production and storability in ecological production systems

    Directory of Open Access Journals (Sweden)

    ghorbani reza

    2009-06-01

    Full Text Available A field experiment was conducted in Shiravan, Iran, during 2005 in order to investigate the effects of organic amendments, synthetic fertilizers and compost extracts on crop health, productivity and storability of commonly used tomato (Lycopersicon esculentum Mill.. Treatments included different fertilizers of cattle, sheep and poultry manures, house-hold compost and chemical fertilizers, and five aqueous extracts from cattle manure, poultry manures, green-waste and house-hold composts and water as control. The effect of fertilizer type on tomato yield and marketable yield was significant (P

  17. DNA extraction procedure affects organic-aggregate-attached bacterial community profiles from a shallow eutrophic lake.

    Science.gov (United States)

    Tang, Xiangming; Gao, Guang; Zhu, Liping; Chao, Jianying; Qin, Boqiang

    2009-06-01

    Organic aggregates (OA) in aquatic ecosystems harbour diverse microbial communities. The colonization and growth of OA-attached bacteria are important processes in the degradation and transformation of the particles. The development of efficient and comparative DNA extraction methods is one of the most critical steps in the study of the composition and diversity of OA-attached bacterial communities. To evaluate whether different DNA extraction procedures affect the measurement of bacterial community composition, we compared four in situ lysis procedures using OA from three locations in a shallow eutrophic lake (Lake Taihu, China). The extracted DNA was analyzed using denaturing gradient gel electrophoresis profiles. We found that the choice of DNA extraction protocol had a significant influence on the fingerprints of the OA-attached bacterial community. This was shown not only in the number of bands but also in their relative representation of certain DNA bands. Using the bead-beating DNA extraction method in the presence of hexadecyltrimethylammonium bromide, we found that crude microbial DNA could be extracted efficiently from different OA types. This protocol is reproducible and gives very pure DNA of relatively high molecular mass. More importantly, the protocol provided more representative and informative data on the diversity of OA-attached bacterial communities.

  18. Investigation of water-soluble organic matter extracted from shales during leaching experiments

    Science.gov (United States)

    Zhu, Yaling; Vieth-Hillebrand, Andrea; Wilke, Franziska D. H.; Horsfield, Brian

    2017-04-01

    The huge volumes and unknown composition of flowback and produced waters cause major public concerns about the environmental and social compatibility of hydraulic fracturing and the exploitation of gas from unconventional reservoirs. Flowback and produced waters contain not only residues of fracking additives but also chemical species that are dissolved from the shales themselves during fluid-rock interaction. Knowledge of the composition, size and structure of dissolved organic carbon (DOC) as well as the main controls on the release of DOC are a prerequisite for a better understanding of these interactions and its effects on composition of flowback and produced water. Black shales from four different geological settings and covering a maturity range Ro = 0.3-2.6% were extracted with deionized water. The DOC yields were found to decrease rapidly with increasing diagenesis and remain low throughout catagenesis. Four DOC fractions have been qualitatively and quantitatively characterized using size-exclusion chromatography. The concentrations of individual low molecular weight organic acids (LMWOA) decrease with increasing maturity of the samples except for acetate extracted from the overmature Posidonia shale, which was influenced by hydrothermal brines. The oxygen content of the shale organic matter also shows a significant influence on the release of organic acids, which is indicated by the positive trend between oxygen index (OI) and the concentrations of formate and acetate. Based on our experiments, both the properties of the organic matter source and the thermal maturation progress of the shale organic matter significantly influence the amount and quality of extracted organic compounds during the leaching experiments.

  19. Evaluating bioavailability of organic pollutants in soils by sequential ultrasonic extraction procedure.

    Science.gov (United States)

    Wu, Xiang; Zhu, Lizhong

    2016-08-01

    Under current retrospective risk assessment framework, the total concentrations of organic pollutants in soils have been employed as the standard for over 30 years. The total concentrations reflect the overall accumulation in soils but tend to be overly conservative for assessing the ecological risks, where the bioavailability plays an important role. In this study, the bioavailability of organic pollutants in soils was evaluated using a stepwise and tiered classification method, namely the sequential ultrasonic extraction procedure (SEUP). The water-soluble and acid-soluble fractions extracted by the SEUP were the bioavailable fractions. The reliability and environmental relevance of the speciation method were examined with representative organic pollutants using the root uptake methods and the semipermeable membrane devices (SPMDs). The plant uptake amounts corrected with weight were highly correlated with the bioavailable fractions (R(2) > 0.75). The amounts of the bioavailable fractions were negatively correlated with the logKow values (R(2) ranging from 0.71 to 0.77) of the organic pollutants and the contents of soil organic matter (R(2) ranging from 0.68 to 0.96). As a refinement of the current risk assessment framework, the SUEP that has proved to be a reliable and convenient is thus highly recommended for evaluating the bioavailability of organic pollutants in soils.

  20. A Quantitative Analysis of Extraction of Organic Molecules from Terrestrial Sedimentary Deposits

    Science.gov (United States)

    Kanik, I.; Beegle, L. W.; Abbey, W. A.; Tsapin, A. T.

    2004-12-01

    There are several factors determining the ability to detect organic molecules as part of a robotic astrobiology mission to planets. These include the quantity of organics present in a sample, the efficiency of extracting those organics from the matrix that they reside in (i.e. sample processing) and finally the detection efficiencies of the analytical instrumentation aboard the robotic platform. Once the detection limits of the analytical instrumentation is established, the efficiency of extraction becomes the overriding factor in the detectability of these molecules, and needs to be factored in. We analyzed four different terrestrial field samples, which were initially created in aqueous environments, are sedimentary in nature. These particular samples were chosen because they possibly represent a terrestrial analog of Mars [1] and they represent a best case scenarios for finding organic molecules on the Martian surface. The extraction efficiencies of amino acids (smallest building blocks of life) from the samples using pyrolysis and solvent extraction techniques (with seven different solvents: water, hydrochloric acid, butane, ethanol, isoproponal, methanol, n=propanal) are reported. In order to remove any instrumental bias, we used a standard laboratory bench-top high pressure liquid chromatograph (HPLC). We determined both absolute quantity of organics as well as the D/L ratio to determine the preservation of that information in the processing step. Acknowledgment: The research described here was carried out at the Jet Propulsion Laboratory, and was sponsored by the NASA PIDDP and ASTID program offices. References: [1] Malin M.C. and Edgett K.S. (2003) Science 302 1931-1934.

  1. Determination of Organic Pollutants in Small Samples of Groundwaters by Liquid-Liquid Extraction and Capillary Gas Chromatography

    DEFF Research Database (Denmark)

    Harrison, I.; Leader, R.U.; Higgo, J.J.W.

    1994-01-01

    A method is presented for the determination of 22 organic compounds in polluted groundwaters. The method includes liquid-liquid extraction of the base/neutral organics from small, alkaline groundwater samples, followed by derivatisation and liquid-liquid extraction of phenolic compounds after...

  2. Determination of Organic Pollutants in Small Samples of Groundwaters by Liquid-Liquid Extraction and Capillary Gas Chromatography

    DEFF Research Database (Denmark)

    Harrison, I.; Leader, R.U.; Higgo, J.J.W.;

    1994-01-01

    A method is presented for the determination of 22 organic compounds in polluted groundwaters. The method includes liquid-liquid extraction of the base/neutral organics from small, alkaline groundwater samples, followed by derivatisation and liquid-liquid extraction of phenolic compounds after...... neutralisation. The extracts were analysed by capillary gas chromatography. Dual detection by flame Ionisation and electron capture was used to reduce analysis time....

  3. On the directionality of halogen bonding.

    Science.gov (United States)

    Huber, Stefan M; Scanlon, Joseph D; Jimenez-Izal, Elisa; Ugalde, Jesus M; Infante, Ivan

    2013-07-07

    The origin of the high directionality of halogen bonding was investigated quantum chemically by a detailed comparison of typical adducts in two different orientations: linear (most stable) and perpendicular. Energy decomposition analyses revealed that the synergy between charge-transfer interactions and Pauli repulsion are the driving forces for the directionality, while electrostatic contributions are more favourable in the less-stable, perpendicular orientation.

  4. Halogen Bonding in (Z-2-Iodocinnamaldehyde

    Directory of Open Access Journals (Sweden)

    Miriam Rossi

    2013-07-01

    Full Text Available Based on the bulkiness of the iodine atom, a non-planar conformation was expected for the title compound. Instead, its molecular structure is planar, as experimentally determined using single crystal X-ray diffraction, and confirmed theoretically by DFT calculations on the single molecule and the halogen pair paired molecules, therefore ruling out crystal packing forces as a principal factor leading to planarity. Indeed, planarity is ascribed to the carbonyl double bond, as when this bond is saturated on forming the related alcohol derivative, the molecule loses planarity. The X-ray molecular structure shows an intermolecular separation between the iodine and the oxygen of the carbonyl shorter than the corresponding van der Waals distance suggesting a weak halogen bond interaction. DFT minimization of this 2-molecule arrangement shows the iodine--oxygen distance much shorter than that observed in the crystal interaction and confirming its stronger halogen bond nature. A trend between increasing I•••O(carbonyl separation and decreasing C-I•••O(carbonyl angle is demonstrated, further confirming the existence of a halogen bond.

  5. Retention of Halogens in Waste Glass

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.

    2010-05-01

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ≤100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  6. Skin Sensitizing Potency of Halogenated Platinum Salts.

    Science.gov (United States)

    The relationship between occupational exposure to halogenated platinum (Pt) salts and Pt-specific allergic sensitization is well-established. Although human case reports and clinical studies demonstrate that Pt salts are potent skin sensitizers, no studies have been published tha...

  7. Syntheses of very dense halogenated liquids.

    Science.gov (United States)

    Ye, Chengfeng; Shreeve, Jean'ne M

    2004-09-17

    A family of halogenated liquids with densities ranging from 1.95 to 2.80 g cm(-3) was readily synthesized by a one-pot procedure. These liquids exhibit characteristics of ionic liquids with melting/transition points lower than room temperature, long liquid ranges, and marked hydrolytic and thermal stabilities.

  8. Retention of Halogens in Waste Glass

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.

    2010-05-01

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ≤100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  9. Impact of solvent extraction organics on adsorption and bioleaching of A. ferrooxidans and L. ferriphilum

    Science.gov (United States)

    Hualong, Yu; Xiaorong, Liu

    2017-04-01

    Copper solvent extraction entrained and dissoluted organics (SX organics) in the raffinate during SX operation can contaminated chalcopyrite ores and influence bioleaching efficiency by raffinate recycling. The adsorption and bioleaching of A. ferrooxidans and L. ferriphilum with contaminated ores were investigated. The results showed that, A. ferrooxidans and L. ferriphilum cells could adsorb quickly on minerals, the adsorption rate on contaminated ores were 83% and 60%, respectively, larger than on uncontaminated ores. However, in the bioleaching by the two kinds of acid bacterias, contaminated ores presented a lower bioleaching efficiency.

  10. Thermal alteration of water extractable organic matter in climosequence soils from the Sierra Nevada, California

    Science.gov (United States)

    Santos, Fernanda; Russell, David; Berhe, Asmeret Asefaw

    2016-11-01

    In the next decades, the influence of wildfires in controlling the cycling and composition of soil organic matter (SOM) globally and in the western U.S. is expected to grow. While the impact of fires on bulk SOM has been extensively studied, the extent at which heating of soil affects the soluble component of SOM remains unclear. Here we investigated the thermal transformations of water-extractable organic matter (WEOM) by examining the changes in the distribution of carbon (C) functional groups in WEOM from soils heated at low and intermediate temperatures. WEOM (exported from soils to rivers in the Sierra Nevada and beyond.

  11. Exciton Diffusion Length and Charge Extraction Yield in Organic Bilayer Solar Cells.

    Science.gov (United States)

    Siegmund, Bernhard; Sajjad, Muhammad T; Widmer, Johannes; Ray, Debdutta; Koerner, Christian; Riede, Moritz; Leo, Karl; Samuel, Ifor D W; Vandewal, Koen

    2017-03-01

    A method for resolving the diffusion length of excitons and the extraction yield of charge carriers is presented based on the performance of organic bilayer solar cells and careful modeling. The technique uses a simultaneous variation of the absorber thickness and the excitation wavelength. Rigorously differing solar cell structures as well as independent photoluminescence quenching measurements give consistent results. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Comparison of Methanol and Tetraglyme as Extraction Solvents for Determination of Volatile Organics in Soil

    Science.gov (United States)

    1987-11-01

    determining volatile organics in soil can be classified into thefollowing groups: 1. Static or dynamic headspace analysis 2. Solvent extraction-direct...methods based on the dynamic headspace method whereby the volatiles are stripped from a soil/water slurry using a conventional purge-and-trap instrument...651. Brazell, R.S. and MP. Maskarinec (1981) Dynamic headspace analysis of solid waste materials. Journal of High Resolution Chromatography and

  13. Effects of organic phase, fermentation media, and operating conditions on lactic Acid extraction.

    Science.gov (United States)

    Hossain, Md Monwar; Maisuria, J L

    2008-01-01

    Lactic acid has extensive uses in the food, pharmaceutical, cosmetic and chemical industry. Lately, its use in producing biodegradable polymeric materials (polylactate) makes the production of lactic acid from fermentation broths very important. The major part of the production cost accounts for the cost of separation from very dilute reaction media where productivity is low as a result of the inhibitory nature of lactic acid. The current method of extraction/separation is both expensive and unsustainable. Therefore, there is great scope for development of alternative technology that will offer efficiency, economic, and environmental benefits. One of the promising technologies for recovery of lactic acid from fermentation broth is reactive liquid-liquid extraction. In this paper the extraction and recovery of lactic acid based on reactive processes is examined and the performance of a hydrophobic microporous hollow-fiber membrane module (HFMM) is evaluated. First, equilibrium experiments were conducted using organic solutions consisting of Aliquat 336/trioctylamine (as a carrier) and tri-butyl phosphate (TBP)/sunflower oil (as a solvent) The values of the distribution coefficient were obtained as a function of feed pH, composition of the organic phase (ratio of carrier to solvent), and temperature (range 8-40 degrees C). The optimum extraction was obtained with the organic phase consisting of a mixture of 15 wt % tri-octylamine (TOA) and 15% Aliquat 336 and 70% solvent. The organic phase with TBP performed best but is less suitable because of its damaging properties (toxicity and environmental impact) and cost. Sunflower oil, which performed moderately, can be regarded as a better option as it has many desirable characteristics (nontoxic, environment- and operator-friendly) and it costs much less. The percentage extraction was approximately 33% at pH 6 and at room temperature (can be enhanced by operating at higher temperatures) at a feed flow rate of 15-20 L

  14. Eye extract improves cell migration out of lymphoid organ explants of L. vannamei and viability of the primary cell cultures.

    Science.gov (United States)

    Li, Wenfeng; Van Tuan, Vo; Van Thuong, Khuong; Bossier, Peter; Nauwynck, Hans

    2015-08-01

    Since no cell line from shrimp has been established up till now, an optimization of the primary cell culture protocol is necessary. In this context, the effect of extracts (supernatant of a 1:50 (w/v) suspension) from different shrimp organs (muscle, brain, ganglia, eyestalk, ovary, and eye) on the performance of primary lymphoid cell cultures was evaluated. Ten percent of eye extract and 3% of ovary extract enhanced maximally the migration and survival of cells of the lymphoid organ of Litopenaeus vannamei significantly at 48, 96, and 144 h post seeding. Extracts from the eyestalk (10%), muscle (10%), and brain (1%) significantly promoted the migration and survival of cells at 48 and 96 h post seeding but not anymore at 144 h post seeding. In conclusion, it may be advised to add 10% of eye extract or 3% of ovary extract to cells for the maximal health of primary cell cultures from the lymphoid organ of L. vannamei.

  15. Effects of Halogen Ions on Phase Equilibrium of Methane Hydrate in Porous Media

    Science.gov (United States)

    Yang, Mingjun; Song, Yongchen; Liu, Yu; Lam, Wei-Haur; Li, Qingping; Yu, Xichong

    2012-05-01

    The influences of halogen ions extracted from sodium fluoride, sodium chloride, sodium bromide, and sodium iodide and their concentrations on methane hydrate phase equilibrium conditions in porous media were investigated experimentally using an orthogonal test method at a pressure of 8 MPa. The experimental results showed that the equilibrium temperature of methane hydrate decreased when halogen ions were added. The equilibrium temperature decreased with the increase of halogen ion concentrations. The influence of the sources of the halogens ion to the methane hydrate equilibrium temperature were insensitive according to variance analysis, which could be explained by about the same mean ionic activity coefficient (a dimensionless coefficient relates the activity to a measured concentration) of sodium fluoride, sodium chloride, sodium bromide, and sodium iodide. The experimental measurements were also in close agreement with the thermodynamic model of Song et al. (J. Nat. Gas Chem. 19, 241 (2010)), in which the mechanical equilibrium of force between the interfaces in a hydrate-liquid-vapor system was considered.

  16. The Brenner Moor - A saline bog as a source for halogenated and non-halogenated volatile compounds

    Science.gov (United States)

    Krause, T.; Studenroth, S.; Furchner, M.; Hoffman, A.; Lippe, S.; Kotte, K.; Schöler, H. F.

    2012-04-01

    The Brenner Moor is a small bog in the catchment area of the river Trave located in Schleswig-Holstein, North Germany, between Baltic and North Sea. The bog is fed by several saline springs with chloride concentrations up to 15 g/L. The high chloride concentrations and the high organic content of the peat make the Brenner Moor an ideal source for the abiotic formation of volatile organic halogenated compounds (VOX). VOX play an important role in the photochemical processes of the lower atmosphere and information on the atmospheric input from saline soils like the Brenner Moor will help to understand the global fluxes of VOX. Soil samples were taken in spring 2011 from several locations and depths in the vicinity of the Brenner Moor. The samples were freeze-dried, ground and incubated in water emphasising an abiotic character for the formation of volatile organic compounds. 1,2-dichloroethane and trichloromethane are the main halogenated compounds emitted from soils of the Brenner Moor. The abiotic formation of trichloromethane as well as other trihalomethanes has been part of intensive studies. A well known source is the decarboxylation of trichloroacetic acid and trichloroacetyl-containing compounds to trichloromethane [1]. Huber et al. discovered another pathway in which catechol, as a model compound for organic substances, is oxidised under Fenton-like conditions with iron(III), hydrogen peroxide and halides to form trihalomethanes [2]. Besides the halogenated compounds, the formation of sulphur compounds such as dimethyl sulfide and dimethyl disulfide and several furan derivatives could be detected which also have an impact on atmospheric chemistry, especially particle formation of clouds. Furan, methylfuran and dimethylfuran are compounds that can be obtained under Fenton-like oxidation from catechol, methyl- and dimethylcatechol and are known to be produced in natural soils [3]. A novel class of furan derivatives that are formed under abiotic conditions from

  17. Effects of aqueous soil-biochar extracts on representative aquatic organisms: a first evaluation

    Science.gov (United States)

    Bastos, A. C.; Abrantes, N.; Prodana, M.; Verheijen, F.; Keizer, J. J.; Soares, A. M. V. M.; Loureiro, S.

    2012-04-01

    Increasing considerations of biochar application to soils has raised concerns over implications to overall environmental quality, associated to some of its components. The heterogeneity of biochar composition is well documented in relation to co-existing chemical species, as a function of feedstock and pyrolysis conditions. Robust ecotoxicology studies with focus on bioavailable biochar components in soil remain scarce and have only started to emerge. This pilot study provides an insight into the potential ecotoxicological effects of aqueous extracts of biochar-amended soil on a range of aquatic organisms (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna), using a battery of standard aquatic bioassays. The use of such bioassays in environmental risk assessment of soil-biochar elutriates is here suggested as a crucial tool, to bridge the gap between biochar's 'inert' fraction in soil and that bioavailable to edaphic organisms. Aqueous extracts were obtained from LUFA 2.2 standard soil (control) and following amendment with pine biochar at common field application rates (80 ton ha-1). Acute exposure to soil-biochar extracts allowed estimating toxicity parameters and developing dose-response curves for all tested species, through well-established methodological guidelines. The bioluminescent bacteria V. fischeri showed negligible EC50 (effect concentration corresponding to 50% luminescence decline) values in the MICROTOX® basic test (independent of exposure time), suggesting low susceptibility to soil-biochar extracts. Mild toxicity was also observed in the microalgae P. subcapitata growth inhibition test, where significant deleterious effects on growth rate occurred only at the highest (100%) extract concentration (pecotoxicological approach, has shown relevance. Preliminary results suggest potential trophic unbalances in aquatic systems, as a result of exposure to leachates from biochar-amended soils.

  18. Antiperoxidative Activity of Tetracarpidium conophorum Leaf Extract in Reproductive Organs of Male Rats

    Directory of Open Access Journals (Sweden)

    Seun Funmilola Akomolafe

    2015-01-01

    Full Text Available Tetracarpidium conophorum (Mull. Arg. Hutch. & Dalz is one of the many medicinal plants used in folklore as male fertility enhancers. This research was aimed at evaluating the anti-peroxidative activity of the leaves of this plant by determining their capacity to reduce malondialdehyde (MDA level in reproductive organs and accessory glands of rats. Adult male rats were administered orally with the aqueous leaf extract from T. conophorum at 50, 500 and 1000 mg/kg body weight for 21 consecutive days while clomiphene citrate (1.04 mg/kg body weight, a fertility drug was used as standard. The results of the study indicated that there was increase in relative organ weight, body weight, mean total food and water consumed by the treated groups. Testicular MDA level was highly significantly different from that of the control (p<0.0001 although a tentatively decreased MDA level was observed. However, MDA levels in the reproductive accessory glands, epididymis, seminal vesicle and prostate gland were insignificantly (p<0.05 lower than those of controls. The highest percentage decrease of MDA level (66.35, 42.68, 62.50 and 63.36% was observed at the highest concentration of the extract (1000 mg/kg in the testis, epididymis, seminal vesicle and prostate gland respectively. These values were two-fold greater than the values obtained for the standard drug. Interestingly, the treatment of rats with the extract significantly increased the activities of superoxide dismutase, catalase (CAT, glutathione peroxidase (GPx, glutathione-S-transferase (GST and the levels of GSH, vitamin C and total protein. Collectively, the results suggest that the extract from T. conophorum leaves had greater capacity to reduce lipid peroxidation in reproductive organs and accessory glands and thus, this plant may be useful in the treatment/management of reproductive cellular damage involving reactive oxygen species.

  19. The variability of standard artificial soils: Behaviour, extractability and bioavailability of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, Jakub, E-mail: hofman@recetox.muni.cz [Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Kamenice 753/5, Brno CZ-62500 (Czech Republic); Hovorková, Ivana [Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Kamenice 753/5, Brno CZ-62500 (Czech Republic); Semple, Kirk T. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2014-01-15

    Highlights: • Artificial soils from different laboratories revealed different fates, behaviour and bioavailability of lindane and phenanthrene. • Lindane behaviour was related to organic carbon. • Phenanthrene behaviour was significantly affected by degrading microorganisms from peat. • Sterilization of artificial soils might reduce unwanted variability. -- Abstract: Artificial soil is an important standard medium and reference material for soil ecotoxicity bioassays. Recent studies have documented the significant variability of their basic properties among different laboratories. Our study investigated (i) the variability of ten artificial soils from different laboratories by means of the fate, extractability and bioavailability of phenanthrene and lindane, and (ii) the relationships of these results to soil properties and ageing. Soils were spiked with {sup 14}C-phenanthrene and {sup 14}C-lindane, and the total residues, fractions extractable by hydroxypropyl-β-cyclodextrin, and the fractions of phenanthrene mineralizable by bacteria were determined after 1, 14, 28 and 56 days. Significant temporal changes in total residues and extractable and mineralizable fractions were observed for phenanthrene, resulting in large differences between soils after 56 days. Phenanthrene mineralization by indigenous peat microorganisms was suggested as the main driver of that, outweighing the effects of organic matter. Lindane total residues and extractability displayed much smaller changes over time and smaller differences between soils related to organic matter. Roughly estimated, the variability between the artificial soils was comparable to natural soils. The implications of such variability for the results of toxicity tests and risk assessment decisions should be identified. We also suggested that the sterilization of artificial soils might reduce unwanted variability.

  20. Characterization of solvent-extractable organics in urban aerosols based on mass spectrum analysis and hygroscopic growth measurement.

    Science.gov (United States)

    Mihara, Toshiyuki; Mochida, Michihiro

    2011-11-01

    To characterize atmospheric particulate organics with respect to polarity, aerosol samples collected on filters in the urban area of Nagoya, Japan, in 2009 were extracted using water, methanol, and ethyl acetate. The extracts were atomized and analyzed using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a hygroscopicity tandem differential mobility analyzer. The atmospheric concentrations of the extracted organics were determined using phthalic acid as a reference material. Comparison of the organic carbon concentrations measured using a carbon analyzer and the HR-ToF-AMS suggests that organics extracted with water (WSOM) and ethyl acetate (EASOM) or those extracted with methanol (MSOM) comprise the greater part of total organics. The oxygen-carbon ratios (O/C) of the extracted organics varied: 0.51-0.75 (WSOM), 0.37-0.48 (MSOM), and 0.27-0.33 (EASOM). In the ion-group analysis, WSOM, MSOM, and EASOM were clearly characterized by the different fractions of the CH and CO(2) groups. On the basis of the hygroscopic growth measurements of the extracts, κ of organics at 90% relative humidity (κ(org)) were estimated. Positive correlation of κ(org) with O/C (r 0.70) was found for MSOM and EASOM, but no clear correlation was found for WSOM.

  1. Application of accelerated solvent extraction in the analysis of organic contaminants, bioactive and nutritional compounds in food and feed.

    Science.gov (United States)

    Sun, Hanwen; Ge, Xusheng; Lv, Yunkai; Wang, Anbang

    2012-05-11

    Accelerated solvent extraction (ASE) has become a popular green extraction technology for different classes of organic contaminants present in numerous kinds of food and feed for food safety. The parameters affecting ASE efficiency and application advancement of ASE in the analysis of organic contaminants, natural toxins compounds as well as bioactive and nutritional compounds in animal origin food, plant origin food and animal feed are reviewed in detail. ASE is a fully automated and reliable extraction technique with many advantages over traditional extraction techniques, so it could be especially useful for routine analyses of pollutants in food and feed.

  2. Determination of silver in soils, sediments, and rocks by organic-chelate extraction and atomic absorption spectrophotometry

    Science.gov (United States)

    Chao, T.T.; Ball, J.W.; Nakagawa, H.M.

    1971-01-01

    A useful method for the determination of silver in soil, sediment, and rock samples in geochemical exploration has been developed. The sample is digested with concentrated nitric acid, and the silver extracted with triisooctyl thiophosphate (TOTP) in methyl isobutyl ketone (MIBK) after dilution of the acid digest to approximately 6 M. The extraction of silver into the organic extractant is quantitative and not affected by the nitric acid concentration from 4 M to 8 M, or by different volumes of TOTP-MIBK. The extracted silver is stable and remains in the organic phase up to several days. The silver concentration is determined by atomic absorption spectrophotometry. ?? 1971.

  3. Analytical methods for the determination of halogens in bioanalytical sciences: a review.

    Science.gov (United States)

    Mello, Paola A; Barin, Juliano S; Duarte, Fabio A; Bizzi, Cezar A; Diehl, Liange O; Muller, Edson I; Flores, Erico M M

    2013-09-01

    Fluorine, chlorine, bromine, and iodine have been studied in biological samples and other related matrices owing to the need to understand the biochemical effects in living organisms. In this review, the works published in last 20 years are covered, and the main topics related to sample preparation methods and analytical techniques commonly used for fluorine, chlorine, bromine, and iodine determination in biological samples, food, drugs, and plants used as food or with medical applications are discussed. The commonest sample preparation methods, as extraction and decomposition using combustion and pyrohydrolysis, are reviewed, as well as spectrometric and electroanalytical techniques, spectrophotometry, total reflection X-ray fluorescence, neutron activation analysis, and separation systems using chromatography and electrophoresis. On this aspect, the main analytical challenges and drawbacks are highlighted. A discussion related to the availability of certified reference materials for evaluation of accuracy is also included, as well as a discussion of the official methods used as references for the determination of halogens in the samples covered in this review.

  4. Inter-layer charge disproportionation in the dual-layer organic metal (tTTF-I)2ClO4 with unsymmetrical I···O halogen bond interactions.

    Science.gov (United States)

    Shin, Kyoung-Soon; Jeannin, Olivier; Brezgunova, Mariya; Dahaoui, Slimane; Aubert, Emmanuel; Espinosa, Enrique; Auban-Senzier, Pascale; Świetlik, Roman; Frąckowiak, Arkadiusz; Fourmigué, Marc

    2014-04-14

    A mixed-valence salt of tTTF-I with ClO4(-), formulated as (tTTF-I)2ClO4, is characterized by the presence of two crystallographically independent donor molecules, segregated in different layers and linked together through I···O interactions with the ClO4(-) anion disordered at room temperature. The tTTF-I donor molecule was prepared by metallation of tTTF (trimethylene tetrathiafulvalene) followed by reaction with iodine to afford the mono and diiodo derivatives tTTF-I and tTTFI2, respectively. The crystal structure of the latter neutral tTTFI2 shows the occurrence of strong type II, II halogen bond interactions. Band structure calculations of the dual-layer structure of the 2 : 1 salt (tTTF-I)2ClO4 show co-existence of both 1D open and 2D closed Fermi surfaces. The salt undergoes a metal-insulator phase transition at T(MI) = 90 K, associated with an electronic dimensionality decrease, since already at 100 K, the 2D part of the Fermi surface transforms into 1D corrugated planes. High resolution X-ray investigations performed at 100 K, combined with multipolar refinements, indicate an approximately equivalent +0.5e charge in both donor molecules, as also deduced from the intramolecular bond distances. On the other hand, Raman spectroscopic investigations show that at ambient temperature the charge is actually distributed non-uniformly in conducting layers of tTTF-I molecules, with the identification of molecules with charges +1, +0.5, 0e, while at low temperature the charge distribution becomes essentially uniform (+0.5e), as confirmed from the X-ray high resolution data. These apparently contradictory behaviors are actually a consequence of a partial electron transfer between the two independent slabs to reach a common Fermi level in the metallic phase.

  5. Manifold Learning with Self-Organizing Mapping for Feature Extraction of Nonlinear Faults in Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Lin Liang

    2015-01-01

    Full Text Available A new method for extracting the low-dimensional feature automatically with self-organization mapping manifold is proposed for the detection of rotating mechanical nonlinear faults (such as rubbing, pedestal looseness. Under the phase space reconstructed by single vibration signal, the self-organization mapping (SOM with expectation maximization iteration algorithm is used to divide the local neighborhoods adaptively without manual intervention. After that, the local tangent space alignment algorithm is adopted to compress the high-dimensional phase space into low-dimensional feature space. The proposed method takes advantages of the manifold learning in low-dimensional feature extraction and adaptive neighborhood construction of SOM and can extract intrinsic fault features of interest in two dimensional projection space. To evaluate the performance of the proposed method, the Lorenz system was simulated and rotation machinery with nonlinear faults was obtained for test purposes. Compared with the holospectrum approaches, the results reveal that the proposed method is superior in identifying faults and effective for rotating machinery condition monitoring.

  6. Use of Organic Solvents to Extract Organochlorine Pesticides (OCPs) from Aged Contaminated Soils

    Institute of Scientific and Technical Information of China (English)

    YE Mao; JIN Xin; JIANG Xin; YANG Xing-Lun; SUN Ming-Ming; BIAN Yong-Rong; WANG Fang; GU Cheng-Gang; WEI Hai-Jiang; SONG Yang; WANG Lei

    2013-01-01

    Problems associated with organochlorine pesticide (OCP)-contaminated sites in China have received wide attention.To solve such problems,innovative ex-situ methods of site remediation are urgently needed.We investigated the feasibility of the extraction method with different organic solvents,ethanol,1-propanol,and three fractions of petroleum ether,using a soil collected from Wujiang (WJ),China,a region with long-term contamination of dichlorodiphenyltrichloroethanes (DDTs).We evaluated different influential factors,including organic solvent concentration,washing time,mixing speed,solution-to-soil ratio,and washing temperature,on the removal of DDTs from the WJ soil.A set of relatively better parameters were selected for extraction with 100 mL L-1 petroleum ether (60-90 ℃):washing time of 180 min,mixing speed of 100 r min-1,solution-to-soil ratio of 10:1,and washing temperature of 50 ℃.These selected parameters were also applied on three other seriously OCP-polluted soils.Results demonstrated their broad-spectrum effectiveness and excellent OCP extraction performance on the contaminated soils with different characteristics.

  7. Downstream extraction process development for recovery of organic acids from a fermentation broth.

    Science.gov (United States)

    Bekatorou, Argyro; Dima, Agapi; Tsafrakidou, Panagiotia; Boura, Konstantina; Lappa, Katerina; Kandylis, Panagiotis; Pissaridi, Katerina; Kanellaki, Maria; Koutinas, Athanasios A

    2016-11-01

    The present study focused on organic acids (OAs) recovery from an acidogenic fermentation broth, which is the main problem regarding the use of OAs for production of ester-based new generation biofuels or other applications. Specifically, 10 solvents were evaluated for OAs recovery from aqueous media and fermentation broths. The effects of pH, solvent/OAs solution ratios and application of successive extractions were studied. The 1:1 solvent/OAs ratio showed the best recovery rates in most cases. Butyric and isobutyric acids showed the highest recovery rates (80-90%), while lactic, succinic, and acetic acids were poorly recovered (up to 45%). The OAs recovery was significantly improved by successive 10-min extractions. Alcohols presented the best extraction performance. The process using repeated extractions with 3-methyl-1-butanol led to the highest OAs recovery. However, 1-butanol can be considered as the most cost-effective option taking into account its price and availability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Light extraction enhancement from organic light-emitting diodes with randomly scattered surface fixture

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Dong-Ying; Shi, Xiao-Bo; Gao, Chun-Hong; Cai, Shi-Duan; Jin, Yue; Liao, Liang-Sheng, E-mail: lsliao@suda.edu.cn

    2014-09-30

    Graphical abstract: - Highlights: • A combination of scattering layer and roughened substrate is used for light extraction from OLEDs. • The scattering layer is readily achieved by spin-coating the TiO{sub 2} sol. • The enhancement relying scattering depends on the size of TiO{sub 2} nano particles. • With the light extraction techniques the uniform emission is achieved. - Abstract: A combination of a scattering medium layer and a roughened substrate was proposed to enhance the light extraction efficiency of organic light-emitting diodes (OLEDs). Comparing with a reference OLED without any scattering layer, 65% improvement in the forward emission has been achieved with a scattering layer formed on an intentionally roughened external substrate surface of the OLED by spin-coating a sol–gel fabricated matrix containing well dispersed titania (TiO{sub 2}) particles. Such a combination method not only demonstrated efficient extraction of the light trapped in the glass substrate but also achieved homogenous emission from the OLED panel. The proposed technique, convenient and inexpensive, is believed to be suitable for the large area OLED production in lighting applications.

  9. Effects of halogenated dibenzo-p-dioxins on the growth of grassy plants: Determination of hazards in mammals fed with contaminated biomass

    Energy Technology Data Exchange (ETDEWEB)

    Kuntsevich, A.D.; Golovkov, V.F.; Chernov, S.A. [Center for Ecotoximetry, Moscow (Russian Federation)] [and others

    1995-03-01

    Halogenated dibenzo-p-dioxins are known to be constant factors of environmental pollution. They are polytropic cell venoms capable of accumulating in the organic matter of the biosphere and being redistributed along food chains. This work was designed to study the dynamics of plant growth in the presence of halogenated dibenzo-p-dioxins and to evaluate the risk incurred by mammals feeding on the contaminated photomass. Our data suggest that halogenate dibenzo-p-dioxins can act as systemic regulators of plant growth. The compound can be transferred by the plant vascular system, a process that makes them toxic and hazardous to mammals. 3 refs., 1 fig., 1 tab.

  10. Organic acid enhanced electrodialytic extraction of lead from contaminated soil fines in suspension

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ahring, Birgitte Kiær; Ottosen, Lisbeth M.

    2007-01-01

    The implementation of soil washing technology for the treatment of heavy metal contaminated soils is limited by the toxicity and unwieldiness of the remaining heavy metal contaminated sludge. In this work, the feasibility of combining electrodialytic remediation with heterotrophic leaching...... for decontamination of the sludge was investigated. The ability of 11 organic acids to extract Pb from the fine fraction of contaminated soil (grains ... was tested. Five of the acids showed the ability to extract Ph from the soil fines in excess of the effect caused solely by pH changes. Addition of the acids, however, severely impeded EDR, hence promotion of EDR by combination with heterotrophic leaching was rejected. In contrast, enhancement of EDR...

  11. Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Kun Wang

    2010-08-01

    Full Text Available Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter. In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules.

  12. Thiacalix[4]arene derivatives containing multiple aromatic groups: High efficient extractants for organic dyes

    Indian Academy of Sciences (India)

    Chuang Yang; Zusheng Wang; Hongyu Guo; Ziyu Jiao; Fafu Yang

    2015-08-01

    Click reaction of alkynylthiacalix[4]arene with ethyl 2-azidoacetate, followed by ammonolysis with hydrazine hydrate and Schiff-base condensation with benzaldehyde or salicyic aldehyde, afforded two novel thiacalix[4]arene derivatives containing multiple aromatic groups in yields of 86% and 90%. Their complexation properties for four organic dyes were investigated by liquid-liquid extraction experiments, complexation UV-Vis spectra and mass spectrum. The highest extraction percentage was 97% for Neutral red. The UV- Vis spectra and ESI-MS spectrum indicated the 1:1 complexes in DMSO solution. The association constants were as high as 1∼ 8 × 104 M−1. These complexation experiments showed that thiacalix[4]arene receptors possess excellent complexation capabilities for dyes.

  13. Molecular characteristics of Kraft-AQ pulping lignin fractionated by sequential organic solvent extraction.

    Science.gov (United States)

    Wang, Kun; Xu, Feng; Sun, Runcang

    2010-08-16

    Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, (13)C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter). In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules.

  14. Efficient Light Extraction from Organic Light-Emitting Diodes Using Plasmonic Scattering Layers

    Energy Technology Data Exchange (ETDEWEB)

    Rothberg, Lewis

    2012-11-30

    Our project addressed the DOE MYPP 2020 goal to improve light extraction from organic light-emitting diodes (OLEDs) to 75% (Core task 6.3). As noted in the 2010 MYPP, “the greatest opportunity for improvement is in the extraction of light from [OLED] panels”. There are many approaches to avoiding waveguiding limitations intrinsic to the planar OLED structure including use of textured substrates, microcavity designs and incorporating scattering layers into the device structure. We have chosen to pursue scattering layers since it addresses the largest source of loss which is waveguiding in the OLED itself. Scattering layers also have the potential to be relatively robust to color, polarization and angular distributions. We note that this can be combined with textured or microlens decorated substrates to achieve additional enhancement.

  15. 54. The Study on the Mutagenicity of Organic Extracts from Fish Raised in Water Containing Effluent

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    objective: To assess the cytogenetic toxicological safety of fish raised in water containing effluent. Methods: Three experimental groups of fish were raised in water that contained effluent. Both fish samples and water samples were collected and analyzed. One group of fish raised in YuQiao reservoir (The source of drinking-water for Tianjin) and a reservoir water sample were collected at the same time as the clean control group. The mutagenicity of organic extracts of the fish was detected using the mice bone marrow micronucleus test and the mutagenicity of the water samples was detected using the micronucleus test of vicia faba root tip cells. Results: The results of the mice bone marrow micronucleus test on organic extracts of the fish showed that the micronucleus rates of the three experimental groups were significantly higher than that of the negative control group (peanut oil) and the clean control group (P0.05) Conclusions: The results indicate that the water containing effluent and the fish raised in this kind of water contain some kinds of organic mutagenic compounds, which might have some potentially hazardous effects on human beings through the food chains.

  16. Does co-extracted dissolved organic carbon cause artefacts in cell-based bioassays?

    Science.gov (United States)

    Neale, Peta A; Escher, Beate I

    2014-08-01

    Bioanalytical tools are increasingly being employed for water quality monitoring, with applications including samples that are rich in natural organic matter (or dissolved organic carbon, DOC), such as wastewater. While issues associated with co-extracted DOC have been identified for chemical analysis and for bioassays with isolated enzymes, little is known about its effect on cell-based bioassays. Using mixture experiments as diagnostic tools, this study aims to assess whether different molecular weight fractions of wastewater-derived DOC adversely affect cell-based bioassays, specifically the bioluminescence inhibition test with the bacteria Vibrio fischeri, the combined algae assay with Pseudokirchneriella subcapitata and the human cell line AREc32 assay for oxidative stress. DOC did not cause suppressive effects in mixtures with reference compounds. Binary mixtures further indicated that co-extracted DOC did not disturb cell-based bioassays, while slight deviations from toxicity predictions for low molecular weight fractions may be partially due to the availability of natural components to V. fischeri, in addition to organic micropollutants.

  17. Halogen bonding origin properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Hobza, Pavel [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague (Czech Republic); Regional Center of Advanced Technologies and Materials, Department of Physical Chemistry, Palacky University, 77146 Olomouc (Czech Republic)

    2015-12-31

    σ-hole bonding represents an unusual and novel type of noncovalent interactions in which atom with σ- hole interacts with Lewis base such as an electronegative atom (oxygen, nitrogen, …) or aromatic systems. This bonding is of electrostatic nature since the σ-hole bears a positive charge. Dispersion energy forms equally important energy term what is due to the fact that two heavy atoms (e.g. halogen and oxygen) having high polarizability lie close together (the respective distance is typically shorter than the sum of van der Waals radii). Among different types of σ-hole bondings the halogen bonding is by far the most known but chalcogen and pnictogen bondings are important as well.

  18. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/....

  19. Tropospheric Chemistry and Climate Impacts of VSL Halogens: Pre-Industrial to Present day

    Science.gov (United States)

    Kinnison, Douglas; Saiz-Lopez, Alfonso; Lamarque, Jean-Francois; Ordoñez, Carlos; Fernandez, Rafael; Tilmes, Simone

    2013-04-01

    Ozone in the troposphere is one of the most important short-lived gases contributing to greenhouse radiative forcing (IPCC, 2007) and is of central importance to the chemistry of this region of the atmosphere. Tropospheric ozone is produced by photochemical oxidation of carbon monoxide, methane and non-methane volatile organic compounds in the presence of nitrogen oxide. A large fraction of the tropospheric ozone loss occurs within the tropical marine boundary layer via photolysis to excited oxygen atoms followed by reaction with water vapor, reactions with odd hydrogen radical, and surface deposition. In addition, inorganic halogens (i.e., chlorine, bromine, and iodine species) are known to destroy ozone through efficient catalytic reaction cycles. In this study, we use the NCAR 3D chemistry climate model (CAM-CHEM). The model has a full representation of tropospheric and stratospheric chemistry. Its scope has been extended to include halogen sources, reactive halogen chemistry, and related atmospheric processes (Ordonez et al. 2012; Saiz-Lopez et al. 2012). The purpose of this work is to contrast the pre-industrial importance of tropospheric halogen driven ozone loss to present day conditions; specifically the importance of iodine chemistry.

  20. Chemistry of Very Short Lived Halogens in the Troposphere: Pre-Industrial to Present day

    Science.gov (United States)

    Kinnison, Douglas; Saiz-Lopez, Alfonso; Fernandez, Rafael; Lamarque, Jean-Francois; Tilmes, Simone

    2014-05-01

    Ozone in the troposphere is one of the most important short-lived gases contributing to greenhouse radiative forcing (IPCC, 2007) and is of central importance to the chemistry of this region of the atmosphere. Tropospheric ozone is produced by photochemical oxidation of carbon monoxide, methane and other non-methane volatile organic compounds in the presence of nitrogen oxide. A large fraction of the tropospheric ozone loss occurs within the tropical marine boundary layer via photolysis to excited oxygen atoms followed by reaction with water vapor, reactions with odd hydrogen radical, and surface deposition. In addition, inorganic halogens (i.e., chlorine, bromine, and iodine species) are known to destroy ozone through efficient catalytic reaction cycles. In this study, we use the NCAR 3D chemistry climate model (CAM-Chem), including a detailed representation of tropospheric and stratospheric chemistry. Its scope has been extended to include halogen sources, reactive halogen chemistry, and related atmospheric processes (Ordonez et al., ACP, 2012; Saiz-Lopez et al., ACP,. 2012). The purpose of this work is to contrast the pre-industrial importance of tropospheric halogen driven ozone loss to present day conditions, specifically the importance of iodine and bromine chemistry. The sensitivity to inorganic nitrogen abundance will be shown. The model results compared to the pre-industrial surface ozone measurements at Montsouris (Volz and Kley, 1988) will also be discussed.

  1. Gas chromatography–mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

    Directory of Open Access Journals (Sweden)

    Laila Salim Al Hashmi

    2013-01-01

    Conclusions: All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T. vulgaris are biologically active molecules. Thus the identification of a good number of compounds in various crude extracts of T. vulgaris might have some ecological role.

  2. Computational Tools To Model Halogen Bonds in Medicinal Chemistry.

    Science.gov (United States)

    Ford, Melissa Coates; Ho, P Shing

    2016-03-10

    The use of halogens in therapeutics dates back to the earliest days of medicine when seaweed was used as a source of iodine to treat goiters. The incorporation of halogens to improve the potency of drugs is now fairly standard in medicinal chemistry. In the past decade, halogens have been recognized as direct participants in defining the affinity of inhibitors through a noncovalent interaction called the halogen bond or X-bond. Incorporating X-bonding into structure-based drug design requires computational models for the anisotropic distribution of charge and the nonspherical shape of halogens, which lead to their highly directional geometries and stabilizing energies. We review here current successes and challenges in developing computational methods to introduce X-bonding into lead compound discovery and optimization during drug development. This fast-growing field will push further development of more accurate and efficient computational tools to accelerate the exploitation of halogens in medicinal chemistry.

  3. Study of the genotoxicity of organic extracts from wastewater-irrigated vegetables using in vitro and in vivo biological tests.

    Science.gov (United States)

    Gao, Hongxia; Cao, Yanhua; Liu, Yingli; Liu, Nan; Guan, Weijun

    2017-01-16

    The purpose of this study was to explore genotoxicity due to organic pollutants in wastewater-irrigated vegetables using biological and chemical analyses. Chinese cabbages from wastewater-irrigated farmland were taken as the research object. For the in vitro test, DNA damage was characterized in rat hepatocytes exposed to organic extracts from the cabbages using the comet assay. For the in vivo tests, mice were exposed to organic extracts from the cabbages. DNA damage was assessed in mouse peripheral blood lymphocytes (PBLs), and chromosome damage was assessed in bone marrow cells using the comet assay and micronucleus test, respectively. For the chemical analysis, gas chromatography-mass spectrometry (GC/MS) was used to analyze the organic compounds in the organic vegetable extracts. The in vitro test results showed that the comet tail lengths of the DNA in rat hepatocytes were significantly increased in the group dosed with 0.36 g/ml (P organic content in the organic vegetable extracts from the wastewater-irrigated area (1.355 mg/kg) was significantly higher than the content in the cabbage samples from the clean-water-irrigated area (0.089 mg/kg). This finding indicated that wastewater irrigation can cause organic pollution with genetic toxicity in vegetables. This study also showed that in vivo and in vitro biological tests can reflect the joint toxicity of organic pollutants, and the test results were in accordance with the chemical analysis of the organic pollutant compositions.

  4. Halogens behaviours in Magma Degassing: Insights into Eruptive Dynamics, Hydrothermal Systems and Atmospheric Impact of Andesitic Volcanism

    Science.gov (United States)

    Villemant, B.; Balcone, H.; Mouatt, J.; Michel, A.; Komorowski, J.; Boudon, G.

    2007-12-01

    Shallow degassing of H2O in andesitic magmas determines the eruptive styles of volcanic eruptions and contributes to the hydrothermal systems developed around active volcanoes. Halogens behaviour during magma degassing primarily depends on their incompatible behaviour in the melts and on water solubility. Thus, residual contents of halogens in volcanic juvenile vitric clasts may be used as tracers of H2O degassing processes during explosive and effusive eruptions. Because of the large range of water-melt partition coefficients of halogens and their relatively low diffusion coefficients, a comparison of F, Cl, Br and I contents in volcanic clasts in function of their vesicularity and micro-cristallinity allows to precisely model the main degassing processes and to establish constraints on pre-eruptive conditions. Halogens acids (HCl, HBr and HI) extracted in the vapour phase have much more complex behaviours because of their high solubility in low temperature thermal waters, their variable condensation temperatures and their very high reactivity when mixed with low temperature and oxidizing atmospheric gases. A comparison of model compositions of high temperature gases with the composition of thermal waters, and gases from fumaroles or plumes of active volcanoes allows to characterise the shallow volcanic system and its evolutionary states. Variable halogen behaviours are discussed for a variety of eruption types (plinian, vulcanian and dome-forming) and active volcanic systems from the Lesser Antilles (Montagne Pelee, Soufrière of Guadeloupe, Soufriere Hills of Montserrat).

  5. Organic substances in produced and formation water from unconventional natural gas extraction in coal and shale

    Science.gov (United States)

    Orem, William H.; Tatu, Calin A.; Varonka, Matthew S.; Lerch, Harry E.; Bates, Anne L.; Engle, Mark A.; Crosby, Lynn M.; McIntosh, Jennifer

    2014-01-01

    Organic substances in produced and formation water from coalbed methane (CBM) and gas shale plays from across the USA were examined in this study. Disposal of produced waters from gas extraction in coal and shale is an important environmental issue because of the large volumes of water involved and the variable quality of this water. Organic substances in produced water may be environmentally relevant as pollutants, but have been little studied. Results from five CBM plays and two gas shale plays (including the Marcellus Shale) show a myriad of organic chemicals present in the produced and formation water. Organic compound classes present in produced and formation water in CBM plays include: polycyclic aromatic hydrocarbons (PAHs), heterocyclic compounds, alkyl phenols, aromatic amines, alkyl aromatics (alkyl benzenes, alkyl biphenyls), long-chain fatty acids, and aliphatic hydrocarbons. Concentrations of individual compounds range from organic carbon (TOC) in CBM produced water is generally in the 1–4 mg/L range. Excursions from this general pattern in produced waters from individual wells arise from contaminants introduced by production activities (oils, grease, adhesives, etc.). Organic substances in produced and formation water from gas shale unimpacted by production chemicals have a similar range of compound classes as CBM produced water, and TOC levels of about 8 mg/L. However, produced water from the Marcellus Shale using hydraulic fracturing has TOC levels as high as 5500 mg/L and a range of added organic chemicals including, solvents, biocides, scale inhibitors, and other organic chemicals at levels of 1000 s of μg/L for individual compounds. Levels of these hydraulic fracturing chemicals and TOC decrease rapidly over the first 20 days of water recovery and some level of residual organic contaminants remain up to 250 days after hydraulic fracturing. Although the environmental impacts of the organics in produced water are not well defined, results

  6. Advances in organic-inorganic hybrid sorbents for the extraction of organic and inorganic pollutants in different types of food and environmental samples.

    Science.gov (United States)

    Ng, Nyuk-Ting; Kamaruddin, Amirah Farhan; Wan Ibrahim, Wan Aini; Sanagi, Mohd Marsin; Abdul Keyon, Aemi S

    2017-08-21

    The efficiency of the extraction and removal of pollutants from food and the environment has been an important issue in analytical science. By incorporating inorganic species into an organic matrix, a new material known as an organic-inorganic hybrid material is formed. As it possesses high selectivity, permeability, and mechanical and chemical stabilities, organic-inorganic hybrid materials constitute an emerging research field and have become popular to serve as sorbents in various separaton science methods. Here, we review recent significant advances in analytical solid-phase extraction employing organic-inorganic composite/nanocomposite sorbents for the extraction of organic and inorganic pollutants from various types of food and environmental matrices. The physicochemical characteristics, extraction properties, and analytical performances of sorbents are discussed; including morphology and surface characteristics, types of functional groups, interaction mechanism, selectivity and sensitivity, accuracy, and regeneration abilities. Organic-inorganic hybrid sorbents combined with extraction techniques are highly promising for sample preparation of various food and environmental matrixes with analytes at trace levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Determination of volatile organic compounds in river water by solid phase extraction and gas chromatography

    Institute of Scientific and Technical Information of China (English)

    M. A. Mottaleb; M. Z. Abedin; M. S. Islam

    2004-01-01

    A simple, rapid, and reproducible method is described employing solid-phase extraction(SPE) using dichloromethane followed by gas chromatography(GC) with flame ionization detection(FID) for determination of volatile organic compound(VOC) from the Buriganga River water of Bangladesh. The method was applied to detect the benzene, toluene, ethylbenzene, xylene and cumene(BTEXC) in the sample collected from the surface or 15 cm depth of water. Two-hundred ml of n-hexane-pretreated and filtered water samples were applied directly to a C18 SPE column. BTEXC were extracted with dichloromethane and average concentrations were obtained as 0.104 to 0.372 (g/ml. The highest concentration of benzene was found as 0.372 (g/ml with a relative standard deviation(RSD) of 6.2%, and cumene was not detected. Factors influencing SPE e.g., adsorbent types, sample load volume, eluting solvent, headspace and temperatures, were investigated. A cartridge containing a C18 adsorbent and using dichloromethane gave better performance for extraction of BTEXC from water.Average recoveries exceeding 90% could be achieved for cumene at 4℃with a 2.7%RSD

  8. Feature extraction techniques using multivariate analysis for identification of lung cancer volatile organic compounds

    Science.gov (United States)

    Thriumani, Reena; Zakaria, Ammar; Hashim, Yumi Zuhanis Has-Yun; Helmy, Khaled Mohamed; Omar, Mohammad Iqbal; Jeffree, Amanina; Adom, Abdul Hamid; Shakaff, Ali Yeon Md; Kamarudin, Latifah Munirah

    2017-03-01

    In this experiment, three different cell cultures (A549, WI38VA13 and MCF7) and blank medium (without cells) as a control were used. The electronic nose (E-Nose) was used to sniff the headspace of cultured cells and the data were recorded. After data pre-processing, two different features were extracted by taking into consideration of both steady state and the transient information. The extracted data are then being processed by multivariate analysis, Linear Discriminant Analysis (LDA) to provide visualization of the clustering vector information in multi-sensor space. The Probabilistic Neural Network (PNN) classifier was used to test the performance of the E-Nose on determining the volatile organic compounds (VOCs) of lung cancer cell line. The LDA data projection was able to differentiate between the lung cancer cell samples and other samples (breast cancer, normal cell and blank medium) effectively. The features extracted from the steady state response reached 100% of classification rate while the transient response with the aid of LDA dimension reduction methods produced 100% classification performance using PNN classifier with a spread value of 0.1. The results also show that E-Nose application is a promising technique to be applied to real patients in further work and the aid of Multivariate Analysis; it is able to be the alternative to the current lung cancer diagnostic methods.

  9. Selected phytotoxins and organic extracts from endophytic fungus Edenia gomezpompae as light reaction of photosynthesis inhibitors.

    Science.gov (United States)

    Macías-Rubalcava, Martha Lydia; Ruiz-Velasco Sobrino, María Emma; Meléndez-González, Claudio; King-Díaz, Beatriz; Lotina-Hennsen, Blas

    2014-09-05

    In a search for natural herbicides, we investigated the action mechanism of the naphthoquinone spiroketals, isolated from the endophytic fungus Edenia gomezpompae: preussomerins EG1 (1) and EG4 (2), and palmarumycins CP17 (3), and CP2 (4) on the photosynthesis light reactions. The naphthoquinone spiroketals 1-4 inhibited the ATP synthesis in freshly lysed spinach thylakoids from water to MV, and they also inhibited the non-cyclic electron transport in the basal, phosphorylating and uncoupled conditions from water to MV. Therefore, they act as Hill reaction inhibitors. The results suggested that naphthoquinone spiroketals 1-4 have two interactions and inhibition site on the PSII electron transport chain. The first one involves the water splitting enzyme inhibition; and, the second on the acceptor site of PSII in a similar way that herbicide Diuron, studied by polaroghaphy and corroborated by fluorescence of the chlorophyll a of PSII. The culture medium and mycelium organic extracts from four morphological variants of E. gomezpompae were phytotoxic, and the culture medium extracts were more potent than mycelium extracts. They also act as Hill reaction inhibitors. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Interaction of bisphenol A with dissolved organic matter in extractive and adsorptive removal processes.

    Science.gov (United States)

    Zhu, Fei-Die; Choo, Kwang-Ho; Chang, Hyun-Shik; Lee, Byunghwan

    2012-05-01

    The fate of endocrine disrupting chemicals (EDCs) in natural and engineered systems is complicated due to their interactions with various water constituents. This study investigated the interaction of bisphenol A (BPA) with dissolved organic matter (DOM) and colloids present in surface water and secondary effluent as well as its adsorptive removal by powdered activated carbons. The solid phase micro-extraction (SPME) method followed by thermal desorption and gas chromatography-mass spectrometry (GC-MS) was utilized for determining the distribution of BPA molecules in water. The BPA removal by SPME decreased with the increased DOM content, where the formation of BPA-DOM complexes in an aqueous matrix was responsible for the reduced extraction of BPA. Colloidal particles in water samples sorbed BPA leading to the marked reduction of liquid phase BPA. BPA-DOM complexes had a negative impact on the adsorptive removal of BPA by powered activated carbons. The complex formation was characterized based on Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy, along with the calculation of molecular interactions between BPA and functional groups in DOM. It was found that the hydrogen bonding between DOM and BPA would be preferred over aromatic interactions. A pseudo-equilibrium molecular coordination model for the complexation between a BPA molecule and a hydroxyl group of the DOM was developed, which enabled estimation of the maximum sorption site and complex formation constant as well as prediction of organic complexes at various DOM levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Improved Production of Paclitaxel from Suspension Culture of Taxus chinensis var.mairei by in situ Extraction with Organic Solvents

    Institute of Scientific and Technical Information of China (English)

    未作君; 元英进; 吴兆亮; 吴金川

    2003-01-01

    The production of paclitaxel from suspension culture of Taxus chinensis var,mairei was improved by in situ extraction with organic solvents to avoid feedback repression and product degradation.Oleic acid and dibutyl phthalate were proved to be suitable solvents .The optimal volumetric percentage of organic solvents in the culture medium was found to be around 8%,and the favorable time for their introduction was at the exponential phase of cell growth,Paclitaxel production with the in situ extraction was ca 3-fold of that without extraction.

  12. Genotoxic potential of organic extracts from particle emissions of diesel and rapeseed oil powered engines.

    Science.gov (United States)

    Topinka, Jan; Milcova, Alena; Schmuczerova, Jana; Mazac, Martin; Pechout, Martin; Vojtisek-Lom, Michal

    2012-07-07

    The present study was performed to identify possible genotoxicity induced by organic extracts from particulate matter in the exhaust of two typical diesel engines run on diesel fuel and neat heated fuel-grade rapeseed oil: a Cummins ISBe4 engine tested using the World Harmonized Steady State Test Cycle (WHSC) and modified Engine Steady Cycle (ESC) and a Zetor 1505 engine tested using the Non-Road Steady State Cycle (NRSC). In addition, biodiesel B-100 (neat methylester of rapeseed oil) was tested in the Cummins engine run on the modified ESC. Diluted exhaust was sampled with high-volume samplers on Teflon coated filters. Filters were extracted with dichlormethane (DCM) and DNA adduct levels induced by extractable organic matter (EOM) in an acellular assay of calf thymus DNA coupled with (32)P-postlabeling in the presence and absence of rat liver microsomal S9 fraction were employed. Simultaneously, the chemical analysis of 12 priority PAHs in EOM, including 7 carcinogenic PAHs (c-PAHs) was performed. The results suggest that diesel emissions contain substantially more total PAHs than rapeseed oil emissions (for the ESC) or that these concentrations were comparable (for the WHSC and NRSC), while c-PAHs levels were comparable (for the ESC) or significantly higher (for the WHSC and NRSC) for rapeseed oil emissions. DNA adduct levels induced by diesel and rapeseed oil derived EOM were comparable, but consistently slightly higher for diesel than for rapeseed oil. Highly significant correlations were found between 12 priority PAHs concentrations and DNA adduct levels (0.980; pparticulate emissions from the combustion of rapeseed oil is significant and is comparable to that from the combustion of diesel fuel. A more detailed study is ongoing to verify and extent these preliminary findings. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  13. Application of natural deep eutectic solvents to the extraction of anthocyanins from Catharanthus roseus with high extractability and stability replacing conventional organic solvents.

    Science.gov (United States)

    Dai, Yuntao; Rozema, Evelien; Verpoorte, Robert; Choi, Young Hae

    2016-02-19

    Natural deep eutectic solvents (NADES) have attracted a great deal of attention in recent times as promising green media. They are generally composed of neutral, acidic or basic compounds that form liquids of high viscosity when mixed in certain molar ratio. Despite their potential, viscosity and acid or basic nature of some ingredients may affect the extraction capacity and stabilizing ability of the target compounds. To investigate these effects, extraction with a series of NADES was employed for the analysis of anthocyanins in flower petals of Catharanthus roseus in combination with HPLC-DAD-based metabolic profiling. Along with the extraction yields of anthocyanins their stability in NADES was also studied. Multivariate data analysis indicates that the lactic acid-glucose (LGH), and 1,2-propanediol-choline chloride (PCH) NADES present a similar extraction power for anthocyanins as conventional organic solvents. Furthermore, among the NADES employed, LGH exhibits an at least three times higher stabilizing capacity for cyanidins than acidified ethanol, which facilitates their extraction and analysis process. Comparing NADES to the conventional organic solvents, in addition to their reduced environmental impact, they proved to provide higher stability for anthocyanins, and therefore have a great potential as possible alternatives to those organic solvents in health related areas such as food, pharmaceuticals and cosmetics.

  14. Solvent extraction of organic acids from stillage for its re-use in ethanol production process.

    Science.gov (United States)

    Castro, G A; Caicedo, L A; Alméciga-Díaz, C J; Sanchez, O F

    2010-06-01

    Stillage re-use in the fermentation stage in ethanol production is a technique used for the reduction of water and fermentation nutrients consumption. However, the inhibitory effect on yeast growth of the by-products and feed components that remains in stillage increases with re-use and reduces the number of possible recycles. Several methods such as ultrafiltration, electrodialysis and advanced oxidation processes have been used in stillage treatment prior its re-use in the fermentation stage. Nevertheless, few studies evaluating the effect of solvent extraction as a stillage treatment option have been performed. In this work, the inhibitory effect of serial stillage recycling over ethanol and biomass production was determined, using acetic acid as a monitoring compound during the fermentation and solvent extraction process. Raw palm oil methyl ester showed the highest acetic acid extraction from the aqueous phase, presenting a distribution coefficient of 3.10 for a 1:1 aqueous phase mixture:solvent ratio. Re-using stillage without treatment allowed up to three recycles with an ethanol production of 53.7 +/- 2.0 g L(-1), which was reduced 25% in the fifth recycle. Alternatively, treated stillage allowed up to five recycles with an ethanol final concentration of 54.7 +/- 1.3 g L(- 1). These results show that reduction of acetic acid concentration by an extraction process with raw palm oil methyl ester before re-using stillage improves the number of recycles without a major effect on ethanol production. The proposed process generates a palm oil methyl ester that contains organic acids, among other by-products, that could be used for product recovery and as an alternative fuel.

  15. Screening of genotoxicity and mutagenicity in extractable organics from oil sands process-affected water.

    Science.gov (United States)

    Zetouni, Nikolas C; Siraki, Arno G; Weinfeld, Michael; Pereira, Alberto Dos Santos; Martin, Jonathan W

    2016-11-01

    Large volumes of oil sands process-affected water (OSPW) are produced by the oil sands surface mining industry during alkaline hot-water extraction of bitumen. It is well documented that the acid extractable organics (AEOs) in OSPW, a highly complex mixture of acidic and polar neutral substances, are acutely toxic; but few studies have examined the genotoxicity or mutagenicity of this mixture. In the present study, the in vitro SOS Chromotest and the Ames test (TA98 and TA100 strains) were used to evaluate genotoxicity and mutagenicity for whole OSPW AEOs in the presence and absence of biotransformation by rat S9 liver enzymes. Two subfractions were also examined in the same assays: neutral extractable fraction (F1-NE), and the subsequent acid extractable fraction (F2-AE). In the SOS assay, whole AEO was cytotoxic when concentrated 2× (i.e., twice as concentrated as the environmental sample) and showed increasing genotoxic response above 6×. Co-exposure with S9 had a protective effect on the cell SOS-inducing factor and survival but did not eliminate genotoxicity above 6× concentrations. Most of the cytotoxicity was attributable to F2-AE, but both F1-NE and F2-AE had similar genotoxic dose-responses above 6×. In the Ames test without S9, whole AEO was mutagenic in both strains above 10× concentrations. Co-incubation with S9 had little effect on the TA100 strain but with TA98 resulted in bioactivation at midlevel doses (1.5-6.3×) and protection at higher doses (10-25×). The 2 subfractions were mutagenic in both strains but with different dose-responses. Further research in vivo or in more relevant cells is warranted to investigate the carcinogenic risks of OSPW. Environ Toxicol Chem 2016;9999:1-8. © 2016 SETAC.

  16. Mild and Moderate Extraction Methods to Assess Potentially Available Soil Organic Nitrogen

    Directory of Open Access Journals (Sweden)

    Bruno Boscov Braos

    Full Text Available ABSTRACT The use of chemical methods to assess the soil organic nitrogen (N potentially available to plants is not a common practice in Brazil. However, associated with others, this tool might improve efficiency in the use of waste and nitrogen fertilizers. In our study, chemical methods were tested to assess potentially available soil N in samples of 17 representative soils of the western plateau of the state of São Paulo (10 Oxisols and 7 Ultisols. Available soil N was extracted from the collected soil samples using moderate (ISNT-Illinois Soil Nitrogen Test and mild (hot water and heated solutions of 2 mol L-1 KCl and 0.01 mol L-1 CaCl2 extraction methods. The levels of potentially available N obtained from these chemical methods were correlated with dry matter (DM and N uptake (Nup by corn plants grown in pots in a greenhouse experiment carried out with the same 17 soil samples. The ISNT method showed the highest available N extraction capacity, whereas hot water showed the lowest capacity, followed closely by the hot 0.01 mol L-1 CaCl2 solution. Despite the differences among the quantities of available N extracted, the methods correlated with each other and with DM and Nup, but the values from the ISNT method showed the lowest correlation with plant variables (rDM = 0.67** and rNup = 0.81**. Procedures of extraction with water or 0.01 mol L-1 CaCl2 heated for 16 h, and 2 mol L-1 KCl heated for 4 h, resulted in similar correlation values (r with plant DM and Nup. Thus, water (rDM = 0.77** and rNup = 0.90** and 0.01 mol L-1 CaCl2 (rDM = 0.82** and rNup = 0.93** heated for 16 h can be recommended as the best options for N extraction.considering the possibility for predicting N availability, lower generation of waste, and lower cost of analysis.

  17. The influence of extractable organic matter on vitrinite reflectance suppression: A survey of kerogen and coal types

    Science.gov (United States)

    Barker, C.E.; Lewan, M.D.; Pawlewicz, M.J.

    2007-01-01

    The vitrinite reflectance suppression literature shows that while bitumen impregnation of the vitrinite group is often invoked as a significant contributor to suppression, its existence is not often supported by petrological evidence. This study examines bitumen impregnation as a factor in vitrinite suppression by comparing the vitrinite reflectance of source rock and coal samples before and after solvent-extraction. Bitumen, often defined as organic matter soluble or extractable in certain organic solvents, should be removed by Soxhlet method solvent extraction using chloroform. Removing the extractable bitumen should restore the suppressed reflectance to its true higher value. However, the solvent extracted samples averaged 0.014% Rv less than that of the unextracted samples. We conclude from these results and from other published data that reflectance suppression by bitumen impregnation in the vitrinite maceral group, above the huminite stage of gelification, is seemingly a rare phenomenon and whose effect on suppressing vitrinite reflectance is typically negligible. ?? 2006.

  18. Organic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-08-15

    This book with sixteen chapter explains organic chemistry on linkage isomerism such as alkane, cycloalkane, alkene, aromatic compounds, stereo selective isomerization, aromatic compounds, stereo selective isomerization, organic compounds, stereo selective isomerization, organic halogen compound, alcohol, ether, aldehyde and ketone, carboxylic acid, dicarboxylic acid, fat and detergent, amino, carbohydrate, amino acid and protein, nucleotide and nucleic acid and spectroscopy, a polymer and medical chemistry. Each chapter has introduction structure and characteristic and using of organic chemistry.

  19. Biodehalogenation: The kinetics and rates of the microbial cleavage of carbon-halogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Castro, C.E. (Univ. of California, Riverside, CA (United States). Nematology Dept.)

    1993-09-01

    Specific rate constants associated with defined molecular paths of carbon-halogen bond cleavage from a variety of alkyl halide substrates by six soil organisms are presented. Five aerobes (three pseudomonads, one methylotroph, and one flavobacterium) and one anaerobe (a methanogen) are compared. The rate constants were obtained with resting cells in phosphate buffer at pH 7.4 in the absence of nutrients or other substances. The observed general rate law is d(X[sup [minus

  20. Hydrophilic solid-phase extraction of melamine with ampholine-modified hybrid organic-inorganic silica material.

    Science.gov (United States)

    Wang, Tingting; Zhu, Yiming; Ma, Junfeng; Xuan, Rongrong; Gao, Haoqi; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2015-01-01

    In this work, an ampholine-functionalized hybrid organic-inorganic silica sorbent was successfully used to extract melamine from a milk formula sample by a hydrophilic interaction solid-phase extraction protocol. Primary factors affecting the extraction efficiency of the material such as extraction solvent, elution solvent, sample loading volume, and elution volume have been thoroughly optimized. Under the optimized hydrophilic solid-phase extraction conditions, the recoveries of melamine spiked in milk formula samples ranged from 86.2 to 101.8% with relative standard deviations of 4.1-9.4% (n = 3). The limit of detection (S/N = 3) was 0.32 μg/g. The adsorption capacity toward melamine was 30 μg of melamine per grams of sorbent. Due to its simplicity, rapidity and cost effectiveness, the newly developed hydrophilic solid-phase extraction method should provide a promising tool for daily monitoring of doped melamine in milk formula.

  1. Organic acids and inorganic anions in Bayer liquors by ion chromatography after solid-phase extraction

    Institute of Scientific and Technical Information of China (English)

    ZHONG Fu-jin; CHEN Xiao-qing; ZHANG Shu-chao; LI Yue-ping

    2007-01-01

    A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, propionate, oxalate, succinate,glutarate, fluoride, chloride and sulfate were separated and determined in 33 min. The samples were pretreated with solid-phase extraction, which has high selectivity for removing a large number of metallic ions in the Bayer liquors, and filtered with a 0.45 μm filter membrane before being injected into the ion chromatographic system. The separation of six organic acids and three inorganic anions was achieved on an IonPac AS11-HC column with KOH as the eluent, and the detection was performed by a conductivity detection mode. No interference is found in the presence of fluorate, chlorate and sulphate when organic acids are determined. The calibration graphs of peak area for all the analytes are linear over a wide range. The relative standard derivation of the peak area of analytes is less than 2.14%. Under optimum conditions the detection ranges from 0.2 to 100.0 mg/L. The average recoveries of the added standards are between 94.3% and 102.8%.

  2. Extraction of lignins from aqueous-ionic liquid mixtures by organic solvents.

    Science.gov (United States)

    Xin, Qin; Pfeiffer, Katie; Prausnitz, John M; Clark, Douglas S; Blanch, Harvey W

    2012-02-01

    The commercial development of ionic liquids (ILs) to pretreat lignocellulose by dissolution of whole biomass and cellulose precipitation by addition of water is hindered by the absence of an effective technique to recover the lignin content of the biomass from the IL. Three organic solvents [ethyl acetate, 1,4-dioxane, and tetrahydrofuran (THF)] were studied for their ability to form a two-liquid-phase system with water and 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]), and for partitioning model lignins and lignin monomers between the two liquid phases. Ternary diagrams were obtained for three [C(2)mim][OAc]/organic solvent/water systems at 22°C. Partition coefficients were measured for several types of lignin in these three systems. Partition coefficients increase with rising water content in the IL phase, and depend strongly on the type of lignin and on the organic solvent. Partition coefficients rise as the pH of the ionic-liquid-rich phase falls. Small molecule model lignin monomer compounds (guaiacol, syringaldehyde) are also readily extracted from the IL/water system by THF. Copyright © 2011 Wiley Periodicals, Inc.

  3. Mercury and halogens in coal: Chapter 2

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Granite, Evan J.; Pennline, Henry W.; Senior, Constance L.

    2014-01-01

    Apart from mercury itself, coal rank and halogen content are among the most important factors inherent in coal that determine the proportion of mercury captured by conventional controls during coal combustion. This chapter reviews how mercury in coal occurs, gives available concentration data for mercury in U.S. and international commercial coals, and provides an overview of the natural variation in halogens that influence mercury capture. Three databases, the U.S. Geological Survey coal quality (USGS COALQUAL) database for in-ground coals, and the 1999 and 2010 U.S. Environmental Protection Agency (EPA) Information Collection Request (ICR) databases for coals delivered to power stations, provide extensive results for mercury and other parameters that are compared in this chapter. In addition to the United States, detailed characterization of mercury is available on a nationwide basis for China, whose mean values in recent compilations are very similar to the United States in-ground mean of 0.17 ppm mercury. Available data for the next five largest producers (India, Australia, South Africa, the Russian Federation, and Indonesia) are more limited and with the possible exceptions of Australia and the Russian Federation, do not allow nationwide means for mercury in coal to be calculated. Chlorine in coal varies as a function of rank and correspondingly, depth of burial. As discussed elsewhere in this volume, on a proportional basis, bromine is more effective than chlorine in promoting mercury oxidation in flue gas and capture by conventional controls. The ratio of bromine to chlorine in coal is indicative of the proportion of halogens present in formation waters within a coal basin. This ratio is relatively constant except in coals that have interacted with deep-basin brines that have reached halite saturation, enriching residual fluids in bromine. Results presented here help optimize mercury capture by conventional controls and provide a starting point for

  4. Boiling Heat Transfer to Halogenated Hydrocarbon Refrigerants

    Science.gov (United States)

    Yoshida, Suguru; Fujita, Yasunobu

    The current state of knowledge on heat transfer to boiling refrigerants (halogenated hydrocarbons) in a pool and flowing inside a horizontal tube is reviewed with an emphasis on information relevant to the design of refrigerant evaporators, and some recommendations are made for future research. The review covers two-phase flow pattern, heat transfer characteristics, correlation of heat transfer coefficient, influence of oil, heat transfer augmentation, boiling from tube-bundle, influence of return bend, burnout heat flux, film boiling, dryout and post-dryout heat transfer.

  5. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, J.B.

    1997-09-01

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

  6. Photoresponsive liquid crystals based on halogen bonding of azopyridines.

    Science.gov (United States)

    Chen, Yinjie; Yu, Haifeng; Zhang, Lanying; Yang, Huai; Lu, Yunfeng

    2014-09-04

    A series of photoresponsive halogen-bonded liquid crystals (LCs) were successfully constructed using molecular halogen and azopyridine compounds, which show interesting properties of photoinduced phase transition upon UV irradiation. In addition, bromine-bonded LCs were first obtained with high mesophase stability.

  7. Scientific conferences: A big hello to halogen bonding

    Science.gov (United States)

    Erdelyi, Mate

    2014-09-01

    Halogen bonding connects a wide range of subjects -- from materials science to structural biology, from computation to crystal engineering, and from synthesis to spectroscopy. The 1st International Symposium on Halogen Bonding explored the state of the art in this fast-growing field of research.

  8. 40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.

    Science.gov (United States)

    2010-07-01

    ..., alkali salt. 721.8900 Section 721.8900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.8900 Substituted halogenated pyridinol, alkali salt. (a) Chemical... as substituted halogenated pyridinols, alkali salts (PMNs P-88-1271 and P-88-1272) are subject to...

  9. 40 CFR 721.8750 - Halogenated substituted pyridine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated substituted pyridine. 721... Substances § 721.8750 Halogenated substituted pyridine. (a) Chemical substances and significant new uses... pyridine (PMN P-86-838) is subject to reporting under this section for the significant new uses...

  10. Rubidium extraction using an organic polymer encapsulated potassium copper hexacyanoferrate sorbent

    KAUST Repository

    Naidu, Gayathri

    2016-07-11

    Sea water reverse osmosis (SWRO) brine contains significant quantity of Rb. As an economically valuable metal, extracting Rb using a suitable and selective extraction method would be beneficial. An inorganic sorbent, copper based potassium hexacyanoferrate (KCuFC), exhibited high selectivity to extract Rb compared to potassium hexacyanoferrate consisting of other transition metal combinations such as Ni, Co and Fe. An organic polymer (polyacrylonitrile, PAN) encapsulated KCuFC (KCuFC-PAN) achieved a Langmuir maximum Rb sorption capacity of 1.23 mmol/g at pH 7.0 ± 0.5. KCuFC-PAN showed Rb selectivity over a wide concentration range of co-existing ions and salinity of SWRO brine. High salinity (0.5-2.5 M NaCl) resulted in 12-30% sorption capacity reduction. At a molar ratio of Li:Rb (21:1), Cs:Rb (0.001:1) and Ca:Rb (14,700:1) commonly found in SWRO brine, sorption reduction of only 18% occurred. Nevertheless, at a very high K:Rb molar ratio (7700:1), KCuFC-PAN sorption capacity of Rb reduced significantly by 65-70%. KCuFC-PAN was well suited for column operation. In a fixed-bed KCuFC-PAN column (influent concentration 0.06 mmol Rb/L, flow velocity 2 m/h), two sorption/desorption cycles were successfully achieved with a maximum Rb sorption capacity of 1.01 (closely similar to the batch study) and 0.85 mmol/g in the first and second cycles, respectively. Around 95% of Rb was desorbed from the column with 0.2 M KCl. Resorcinol formaldehyde (RF) resin showed promising results of separating Rb from K/Rb mixed solution in effluents from a fixed-bed column, and a subsequent sequential acid desorption, producing 68% purified Rb.

  11. Automatic In-Syringe Dispersive Microsolid Phase Extraction Using Magnetic Metal-Organic Frameworks.

    Science.gov (United States)

    Maya, Fernando; Palomino Cabello, Carlos; Estela, Jose Manuel; Cerdà, Víctor; Turnes Palomino, Gemma

    2015-08-04

    A novel automatic strategy for the use of micro- and nanomaterials as sorbents for dispersive microsolid phase extraction (D-μ-SPE) based on the lab-in-syringe concept is reported. Using the developed technique, the implementation of magnetic metal-organic framework (MOF) materials for automatic solid-phase extraction has been achieved for the first time. A hybrid material based on submicrometric MOF crystals containing Fe3O4 nanoparticles was prepared and retained in the surface of a miniature magnetic bar. The magnetic bar was placed inside the syringe of an automatic bidirectional syringe pump, enabling dispersion and subsequent magnetic retrieval of the MOF hybrid material by automatic activation/deactivation of magnetic stirring. Using malachite green (MG) as a model adsorption analyte, a limit of detection of 0.012 mg/L and a linear working range of 0.04-2 mg/L were obtained for a sample volume equal to the syringe volume (5 mL). MG preconcentration was linear up to a volume of 40 mL, obtaining an enrichment factor of 120. The analysis throughput is 18 h(-1), and up to 3000 extractions/g of material can be performed. Recoveries ranging between 95 and 107% were obtained for the analysis of MG in different types of water and trout fish samples. The developed automatic D-μ-SPE technique is a safe alternative for the use of small-sized materials for sample preparation and is readily implementable to other magnetic materials independent of their size and shape and can be easily hyphenated to the majority of detectors and separation techniques.

  12. Effect of extracts of the reproductive organs of brassica oleracea L. on morphogenesis in Vitro

    Directory of Open Access Journals (Sweden)

    R.N. KIRAKOSJAN

    2014-07-01

    Full Text Available Currently, cabbage is the most common vegetable. The reason is very tasty and chemical composition. It contains 2,6-5,7% sugar, 1,1-2,3% of the proteins, minerals phosphorus, potassium, magnesium, zinc, manganese, iodine, etc. The most important problem of selection is still reducing the time to development new varieties.Broad prospects in the intensification of the selection process opens the application of modern techniques of applied genetics and applied biotechnology, combined with hybridization and selection. Great theoretical and practical interest, in particular, the use of haploidy. Method dihaploids allows significant acceleration of the process of selection of all cultivated plants.Work carried out on varieties and F1 hybrids of the genus Brassica: cabbage (B. oleracea L.: F1 hybrid Jubilei, line ET1 and AMF 3L. Plants - donors were grown in a greenhouse of the Breeding Timofeev-station of RSAU-MTAA during the year. Objects of our research were isolated anthers, microspores, ovaries and ovules of cabbage.Studied the effects of extracts derived from the reproductive organs of cabbage. As the solvent used: DMSO, acetone, alcohol and water. The extracts were added to a sterile medium. For cabbage we have optimized steps of obtaining regenerated plants by direct embryogenesis from microspores of isolated anthers. Found that the presence of hormones in MS medium at a concentration of NAA 1 mg / l, Dropp - 0.01 mg / l stimulated the process of direct embryogenesis. In these conditions the microspores in anther maintain their viability for a long growing in in vitro. The addition of DMSO-based extracts and acetone resulted in the induction of development of the ovaries and ovules. This was manifested in the growth of the ovaries and the formation of larger ovules. In variants with water and alcohol, this effect was not observed.

  13. Red wine extract, resveratrol, on maintenance of organ function following trauma-hemorrhage

    Directory of Open Access Journals (Sweden)

    Fu-Chao Liu

    2012-10-01

    Full Text Available ABSTRACT:Resveratrol, is a polyphenol that can be extracted from grapes and red wine, possess potential anti-inflammatory effects, which would result in the reduction of cytokine production, the alteration of the expression of adhesion molecule molecules, and the inhibition of neutrophil function. Resveratrol might also act as an antioxidant, anti-aging, and control of cell cycle and apoptosis. Resveratrol has been shown to have protective effects for patients inshock-like states. Such protective phenomenon is reported to be implicated in a variety of intracellular signaling pathways including the regulation of the mitogen-activated protein kinases (MAPK/ hemeoxygenase-1 (HO-1 pathway, activates estrogen receptor (ER, and the mediation of pro-inflammatory cytokines, reactive oxygen species (ROS formation and reactive. Moreover, through anti-inflammatory effects and antioxidant properties, the resveratrol is believed to maintain organ function following trauma-hemorrhage.

  14. Light extraction from organic light-emitting diodes for lighting applications by sand-blasting substrates.

    Science.gov (United States)

    Chen, Shuming; Kwok, Hoi Sing

    2010-01-04

    Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost-effective method to rough the substrates and hence to scatter the light. By simply sand-blasting the edges and back-side surface of the glass substrates, a 20% improvement of forward efficiency has been demonstrated. Moreover, due to scattering effect, a constant color over all viewing angles and uniform light pattern with Lambertian distribution has been obtained. This simple and cost-effective method may be suitable for mass production of large-area OLEDs for lighting applications.

  15. Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

    Institute of Scientific and Technical Information of China (English)

    Laila Salim Al Hashmi; Mohammad Amzad Hossain; Afaf Mohammed Weli; Qasim Al-Riyami; Jamal Nasser Al-Sabahi

    2013-01-01

    Objective: To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L (T. vulgaris) by gas chromatography-mass spectrometry (GC-MS). Methods: The shade dried leaves powder was extracted with methanol by using Soxhlet extractor. Methanol crude extracts of T. vulgaris and the derived fractions of hexane, chloroform, ethyl acetate and butanol were obtained. Results: Qualitative analyses of various organic crude extracts of T. vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds. Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important. Further, the T. vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation. The crude extracts were prepared from the powder leaves of T. vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis. Conclusions: All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T. vulgaris are biologically active molecules. Thus the identification of a good number of compounds in various crude extracts of T. vulgaris might have some ecological role.

  16. Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

    Institute of Scientific and Technical Information of China (English)

    Laila; Salim; Al; Hashmi; Mohammad; Amzad; Hossain; Afaf; Mohammed; Weli; Qasim; Al-Riyami; Jamal; Nasser; Al-Sabahi

    2013-01-01

    Objective:To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L(T.vulgaris)by gas chromatography-mass spectrometry(GC-MS).Methods:The shade dried leaves powder was extracted with methanol by using Soxhlet extractor.Methanol crude extracts of T.vulgaris and the derived fractions of hexane,chloroform,ethyl acetate and butanol were obtained.Results:Qualitative analyses of various organic crude extracts of T.vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds.Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important.Further,the T.vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation.The crude extracts were prepared from the powder leaves of T.vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis.Conclusions:All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T.vulgaris are biologically active molecules.Thus the identification of a good number of compounds in various crude extracts of T.vulgaris might have some ecological role.

  17. Solid-phase extraction with metal-organic frameworks for the analysis of chiral compounds.

    Science.gov (United States)

    Tang, Bo; Zhang, Jun-Hui; Zi, Min; Chen, Xue-Xian; Yuan, Li-Ming

    2016-12-01

    Metal-organic frameworks (MOFs) are excellent porous materials with nanoscale cavities and high surface areas, which make them promising as novel adsorbents in solid-phase extraction (SPE). In this article we report a new application of the chiral MOF [Zn2 (D-Cam)2 (4,4'-bpy)]n in SPE used for the measurement of the enantiomeric excess (ee) of (±)-1,1'-bi-2-naphthol. Several important experimental parameters that may influence the extraction efficiency were investigated and optimized. Under the optimum conditions, a good linearity (R(2)  > 0.999) was found between the ee value and the reciprocal of the peak areas. When compared with the actual ee measured using chiral HPLC, the SPE-based assay also showed good accuracy and precision. The results showed that SPE based on chiral MOFs as adsorbents is a simple and effective method for the determination of the ee values of chiral compounds. © 2016 Wiley Periodicals, Inc.

  18. Spectral-distortion-free light extraction from organic light-emitting diodes using nanoscale photonic crystal

    Science.gov (United States)

    Shim, Yong Sub; Nyun Kim, Kyu; Hwang, Ju Hyun; Hwee Park, Cheol; Jung, Sun-Gyu; Park, Young Wook; Ju, Byeong-Kwon

    2017-01-01

    Despite their generally good performance, photonic crystal (PC)-based organic light-emitting diodes (OLEDs) encounter a serious spectral distortion problem. In this study, we obtained spectral-distortion-free PC-based OLEDs by lowering the pitch (period of the PC) to less than a half the emission wavelength, using a simple and scalable nanoscale process of laser interference lithography. The demonstrated OLEDs with 200 nm pitch-size nanoscale periodic hole arrays exhibited negligible changes in the Internal Commission on Illumination 1931 color coordinate of Δ (0.0104, 0.0078) and a peak wavelength of Δ0 nm (relative to the reference), while maintaining the function of the internal light extraction layer, manifested as a 23% enhancement of the external quantum efficiency (EQE). The enhancement of the EQE reached 85% after incorporating a micro-lens array. The improved light extraction, spectral-distortion-free characteristic, and excellent color stability over a broad range of viewing angles were successfully derived by performing finite difference time domain simulations.

  19. Solid-liquid extraction of alkali metals and organic compounds by leaching of food industry residues.

    Science.gov (United States)

    Yu, Chaowei; Zheng, Yi; Cheng, Yu-Shen; Jenkins, Bryan M; Zhang, Ruihong; VanderGheynst, Jean S

    2010-06-01

    Leaching was studied for its application in extracting inorganic and organic constituents from fresh fermented grape pomace, air-dried fermented grape pomace and air-dried sugar beet pulp. Samples of each feedstock were leached in water at ambient temperature for 30 or 120 min at dry solid-to-liquid ratios of 1/20 and 1/50 kg/L. Leaching removed 82% of sodium, 86% of potassium, and 76% of chlorine from sugar beet pulp, and reduced total ash concentration in air-dry fermented grape pomace from 8.2% to 2.9% of dry matter, 8.2% to 4.4% in fresh fermented grape pomace, and 12.5% to 5.4% in sugar beet pulp. Glycerol (7-11 mg/dry g), ethanol (131-158 mg/dry g), and acetic acid (24-31 mg/dry g) were also extracted from fermented grape pomace. These results indicate that leaching is a beneficial pretreatment step for improving the quality of food processing residues for thermochemical and biochemical conversion.

  20. Isolation of plant DNA for PCR and genotyping using organic extraction and CTAB.

    Science.gov (United States)

    Springer, Nathan M

    2010-11-01

    A general difficulty in isolation of DNA from plant cells is the presence of a cell wall. It is necessary to degrade plant cell walls, either physically or enzymatically, in order to effectively isolate plant DNA. Additionally, some tissues (such as endosperm) or some species contain high levels of starches or phenolic compounds that can complicate DNA isolation. A number of plant DNA isolation protocols are designed to overcome species-specific difficulties. This is a relatively simple protocol that uses an extraction buffer containing cetyltrimethylammonium bromide (CTAB); it can be used for many plant species. It provides a substantial amount of high-quality DNA that is suitable for polymerase chain reaction (PCR) procedures and is stable for long periods of time. The cost per sample is very low. In addition, this protocol is relatively robust and can be performed by individuals who have had relatively little training. A typical undergraduate student can perform ~200-300 isolations in a day using this protocol. The disadvantages are that it requires a freeze-dryer and a mill or paint-shaker-like device and that it utilizes an organic extraction step, requiring the use of a fume hood.

  1. Dual use of tantalum disulfides as hole and electron extraction layers in organic photovoltaic cells.

    Science.gov (United States)

    Le, Quyet Van; Nguyen, Thang Phan; Choi, Kyoung Soon; Cho, Yoon-Ho; Hong, Young Joon; Kim, Soo Young

    2014-12-14

    UV/ozone treated (UVO-treated) TaS2 and non-treated TaS2 nanosheets are introduced into organic photovoltaic cells (OPVs) as hole extraction layers (HEL) and electron extraction layers (EEL). TaS2 nanosheets are obtained via ultrasonic vibration and size-controlled by centrifugation. Atomic force microscopy (AFM) images reveal that the thickness and lateral size of TaS2 nanosheets are approximately 1 and 70 nm, indicating that uniform and ultrathin TaS2 nanosheets are obtained. The work function of TaS2 increases from 4.4 eV to 4.9-5.1 eV after applying UVO treatment by forming Ta2O5. In addition, the power conversion efficiencies of normal OPV with UVO-treated TaS2 and inverted OPV with TaS2 are 3.06 and 2.73%, which are higher than those of OPV without TaS2 (1.56% for normal OPV and 0.22% for inverted OPV). These results indicate that TaS2 is a promising material for HEL and EEL layers in OPVs.

  2. Band-Tail Transport of CuSCN: Origin of Hole Extraction Enhancement in Organic Photovoltaics.

    Science.gov (United States)

    Kim, Minju; Park, Soohyung; Jeong, Junkyeong; Shin, Dongguen; Kim, Jimin; Ryu, Sae Hee; Kim, Keun Su; Lee, Hyunbok; Yi, Yeonjin

    2016-07-21

    Copper thiocyanate (CuSCN) is known as a promising hole transport layer in organic photovoltaics (OPVs) due to its good hole conduction and exciton blocking abilities with high transparency. Despite its successful device applications, the origin of its hole extraction enhancement in OPVs has not yet been understood. Here, we investigated the electronic structure of CuSCN and the energy level alignment at the poly(3-hexylthiophene-2,5-diyl) (P3HT)/CuSCN/ITO interfaces using ultraviolet photoelectron spectroscopy. The band-tail states of CuSCN close to the Fermi level (EF) were observed at 0.25 eV below the EF, leading to good hole transport. The CuSCN interlayer significantly reduces the hole transport barrier between ITO and P3HT due to its high work function and band-tail states. The barrier reduction leads to enhanced current density-voltage characteristics of hole-dominated devices. These results provide the origin of hole-extraction enhancement by CuSCN and insights for further application.

  3. DNA Extraction Protocols for Whole-Genome Sequencing in Marine Organisms.

    Science.gov (United States)

    Panova, Marina; Aronsson, Henrik; Cameron, R Andrew; Dahl, Peter; Godhe, Anna; Lind, Ulrika; Ortega-Martinez, Olga; Pereyra, Ricardo; Tesson, Sylvie V M; Wrange, Anna-Lisa; Blomberg, Anders; Johannesson, Kerstin

    2016-01-01

    The marine environment harbors a large proportion of the total biodiversity on this planet, including the majority of the earths' different phyla and classes. Studying the genomes of marine organisms can bring interesting insights into genome evolution. Today, almost all marine organismal groups are understudied with respect to their genomes. One potential reason is that extraction of high-quality DNA in sufficient amounts is challenging for many marine species. This is due to high polysaccharide content, polyphenols and other secondary metabolites that will inhibit downstream DNA library preparations. Consequently, protocols developed for vertebrates and plants do not always perform well for invertebrates and algae. In addition, many marine species have large population sizes and, as a consequence, highly variable genomes. Thus, to facilitate the sequence read assembly process during genome sequencing, it is desirable to obtain enough DNA from a single individual, which is a challenge in many species of invertebrates and algae. Here, we present DNA extraction protocols for seven marine species (four invertebrates, two algae, and a marine yeast), optimized to provide sufficient DNA quality and yield for de novo genome sequencing projects.

  4. In vitro antibacterial properties of essential oil and organic extracts of Premna integrifolia Linn

    Directory of Open Access Journals (Sweden)

    Atiqur Rahman

    2016-09-01

    Full Text Available The aims of this study were to examine the chemical composition of the essential oil of Premna integrifolia Linn (Lamiaceae, and to test the efficacy of the oil and various organic extracts as an antibacterial potential. The chemical compositions of the essential oil were analyzed by GC–MS. Twenty-nine compounds representing 94.81% of the total leaves oil were identified, of which phytol (27.25%, α-humulene (14.21%, spathulenol (12.12%, 1-octen-3-ol (8.21%, eugenol (6.69% and phenylethyl alcohol (5.81% were the major compounds. The oil (15 μL disk−1 and extracts (300 μg disk−1 of P. integrifolia displayed a great potential of antibacterial activity against Sarcina lutea IFO 3232, Bacillus subtilis IFO 3026, Escherichia coli IFO 3007, Pseudomonas sp. ATCC 13867, Klebsiella pneumoniae ATCC 10031 and Xanthomonas campestries IAM 1671 with their respective zones of inhibition of 12.0 ± 1.2 to 22.1 ± 1.2 mm and MIC values of 62.5–250 μg mL−1. The results of this study suggest that the natural products derived from P. integrifolia may have potential use in food, pharmaceutical and/or agro industries for preservatives or antimicrobial agents.

  5. Organic compounds in water extracts of coal: links to Balkan endemic nephropathy.

    Science.gov (United States)

    Maharaj, S V M; Orem, W H; Tatu, C A; Lerch, H E; Szilagyi, D N

    2014-02-01

    The Pliocene lignite hypothesis is an environmental hypothesis that has been proposed to explain the etiology of Balkan endemic nephropathy (BEN). Aqueous leaching experiments were conducted on a variety of coal samples in order to simulate groundwater leaching of organic compounds, and to further test the role of the Pliocene lignite hypothesis in the etiology of BEN. Experiments were performed on lignite coal samples from endemic BEN areas in Romania and Serbia, and lignite and bituminous coals from nonendemic regions in Romania and the USA. Room temperature, hot water bath, and Soxhlet aqueous extraction experiments were conducted between 25 and 80 °C, and from 5 to 128 days in duration. A greater number of organic compounds and in higher concentrations were present in all three types of leaching experiments involving endemic area Pliocene lignite samples compared to all other coals examined. A BEN causing molecule or molecules may be among phenols, PAHs, benzenes, and/or lignin degradation compounds. The proposed transport pathway of the Pliocene lignite hypothesis for organic compound exposure from endemic area Pliocene lignite coals to well and spring drinking water, is likely. Aromatic compounds leached by groundwater from Pliocene lignite deposits in the vicinity of endemic BEN areas may play a role in the etiology of the disease. A better understanding of organic compounds leached by groundwater from Pliocene lignite deposits may potentially lead to the identification and implementation of effective strategies for the prevention of exposure to the causative agent(s) for BEN, and in turn, prevention of the disease.

  6. Crystal structures of four δ-keto esters and a Cambridge Structural Database analysis of cyano-halogen interactions.

    Science.gov (United States)

    Kamal, Kulsoom; Maurya, Hardesh K; Gupta, Atul; Vasudev, Prema G

    2015-10-01

    The revived interest in halogen bonding as a tool in pharmaceutical cocrystals and drug design has indicated that cyano-halogen interactions could play an important role. The crystal structures of four closely related δ-keto esters, which differ only in the substitution at a single C atom (by H, OMe, Cl and Br), are compared, namely ethyl 2-cyano-5-oxo-5-phenyl-3-(piperidin-1-yl)pent-2-enoate, C19H22N2O3, (1), ethyl 2-cyano-5-(4-methoxyphenyl)-5-oxo-3-(piperidin-1-yl)pent-2-enoate, C20H24N2O4, (2), ethyl 5-(4-chlorophenyl)-2-cyano-5-oxo-3-(piperidin-1-yl)pent-2-enoate, C19H21ClN2O3, (3), and the previously published ethyl 5-(4-bromophenyl)-2-cyano-5-oxo-3-(piperidin-1-yl)pent-2-enoate, C19H21BrN2O3, (4) [Maurya, Vasudev & Gupta (2013). RSC Adv. 3, 12955-12962]. The molecular conformations are very similar, while there are differences in the molecular assemblies. Intermolecular C-H...O hydrogen bonds are found to be the primary interactions in the crystal packing and are present in all four structures. The halogenated derivatives have additional aromatic-aromatic interactions and cyano-halogen interactions, further stabilizing the molecular packing. A database analysis of cyano-halogen interactions using the Cambridge Structural Database [CSD; Groom & Allen (2014). Angew. Chem. Int. Ed. 53, 662-671] revealed that about 13% of the organic molecular crystals containing both cyano and halogen groups have cyano-halogen interactions in their packing. Three geometric parameters for the C-X...N[triple-bond]C interaction (X = F, Cl, Br or I), viz. the N...X distance and the C-X...N and C-N...X angles, were analysed. The results indicate that all the short cyano-halogen contacts in the CSD can be classified as halogen bonds, which are directional noncovalent interactions.

  7. Mechanism of extractant loss in solvent extraction process (Ⅰ)——Transfer of saponified D2EHPA from organic phase to aqueous phase and its aggregation behaviour

    Institute of Scientific and Technical Information of China (English)

    王笃金; 吴瑾光; 李彦; 翁诗甫; 吴佩强; 徐光宪

    1995-01-01

    The phenomenon of the loss of saponified D2EHPA(di(2-ethylhexyl)phosphoric acid,HA)from organic phase to aqueous phase and its aggregation behaviour were studied with FT-IR and DLS(dynamic light scattering)techniques based on the fact that saponified extractant can form reversed micelles orw/o microemulsions in n-heptane,a non-polar diluent.The results indicate that "normal rnioelles" or o/wmicroemulsions are formed from acidic extractant and its sodium salt in aqueous phase,and the micelle ormicroemulsion drop has a non-polar core which can solubilize nheptane,so the equilibrated aqueous phasecontaining extractant is a complex fluid rather than a "real solution".Therefore,the aqueous aggregate for-mation leads to the extractant loss in solvent extraction process.Strong electrolytes can prevent or lessen theextractant loss.The results of this paper provide a theoretical possibility for solving the problem ofextractant and solvent loss in liquid-liquid extraction industry.

  8. Chlorinated organic compounds in urban river sediments

    Energy Technology Data Exchange (ETDEWEB)

    Soma, Y.; Shiraishi, H.; Inaba, K. [National Inst. of Environmental Studies, Tsukuba, Ibaraki (Japan)

    1995-12-31

    Among anthropogenic chemicals, many chlorinated organic compounds have been used as insecticides and detected frequently as contaminants in urban river sediments so far. However, the number and total amount of chemicals produced commercially and used are increasing year by year, though each amount of chemicals is not so high. New types of contaminants in the environment may be detected by the use of newly developed chemicals. Chlorinated organic compounds in the urban river sediments around Tokyo and Kyoto, large cities in Japan, were surveyed and recent trends of contaminants were studied. Contaminants of the river sediments in industrial areas had a variety, but PCB (polychlorinated biphenyls) was detected in common in industrial areas. Concentration of PCB related well to the number of factories on both sides of rivers, although the use of PCB was stopped 20 years ago. In domestic areas, Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) and Triclocarban (3,4,4{prime}-trichlorocarbanilide)(both are contained in soap or shampoo for fungicides), p-dichlorobenzene (insecticides for wears) and TCEP(tris-chloroethyl phosphate) were detected. EOX(extracted organic halogen) in the sediments was 5 to 10 times of chlorinated organic compounds detected by GC/MS. Major part of organic halogen was suggested to be included in chlorinated organics formed by bleaching or sterilization.

  9. Hydrogen bond and halogen bond inside the carbon nanotube

    Science.gov (United States)

    Wang, Weizhou; Wang, Donglai; Zhang, Yu; Ji, Baoming; Tian, Anmin

    2011-02-01

    The hydrogen bond and halogen bond inside the open-ended single-walled carbon nanotubes have been investigated theoretically employing the newly developed density functional M06 with the suitable basis set and the natural bond orbital analysis. Comparing with the hydrogen or halogen bond in the gas phase, we find that the strength of the hydrogen or halogen bond inside the carbon nanotube will become weaker if there is a larger intramolecular electron-density transfer from the electron-rich region of the hydrogen or halogen atom donor to the antibonding orbital of the X-H or X-Hal bond involved in the formation of the hydrogen or halogen bond and will become stronger if there is a larger intermolecular electron-density transfer from the electron-rich region of the hydrogen or halogen atom acceptor to the antibonding orbital of the X-H or X-Hal bond. According to the analysis of the molecular electrostatic potential of the carbon nanotube, the driving force for the electron-density transfer is found to be the negative electric field formed in the carbon nanotube inner phase. Our results also show that the X-H bond involved in the formation of the hydrogen bond and the X-Hal bond involved in the formation of the halogen bond are all elongated when encapsulating the hydrogen bond and halogen bond within the carbon nanotube, so the carbon nanotube confinement may change the blue-shifting hydrogen bond and the blue-shifting halogen bond into the red-shifting hydrogen bond and the red-shifting halogen bond. The possibility to replace the all electron nanotube-confined calculation by the simple polarizable continuum model is also evaluated.

  10. Halogen control in integrated hot gas cleaning: final report

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.; Kangasmaa, K.; Laatikainen-Luntama, J.; Kurkela, E. [VTT Energy (Finland)

    1998-12-31

    A simple and cost effective dry-scrubbing halogen control method for hot gasification gas cleaning applications was developed. The work aimed to develop a dry scrubbing method for integration into a hot gas cleaning system including particulate removal by cyclones, filtration and possibly a desulphurisation system. Work started by determining the behaviour of halogen compounds in a reducing gasification atmosphere to evaluate the fate of halogens on downstream components, to understand the role of halogens as precursors for environmental emissions, and to give background information for developing halogen control methods. New halogen sampling and analysis methods for pressurised gasification gas conditions were also developed. Mass balances were determined for several gasification conditions, with and without calcium-based bed additives. Several potential dry scrubbing sorbent candidates were evaluated. Chemical, technical, economical and environmental aspects were used as selection criteria, calcium-based sorbents being chosen for development of the halogen removal system. The process concept was based on sorbent feeding into the product gas prior to the hot gas filter unit, where the final step of halogen capture takes place and both sorbent and particulates are removed from the gas. Preliminary screening of calcium-based sorbents and preoptimisation of process conditions was performed in a laboratory scale dry scrubbing test rig. Finally, the performance of the developed dry scrubbing halogen removal system was verified in a PDU scale pressurised fluidised bed gasification and gas cleaning test rig. Preliminary verification showed that, in favourable conditions, the system developed formed a potential halogen control system that could be easily integrated into the other hot gas cleaning systems. 2 refs., 9 figs., 2 tabs.

  11. [Near infrared light irradiator using halogen lamp].

    Science.gov (United States)

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  12. Effects of organic extracts of six Bangladeshi plants on in vitro thrombolysis and cytotoxicity

    Directory of Open Access Journals (Sweden)

    Rahman M Atiar

    2013-01-01

    Full Text Available Abstract Background Thrombus formed in blood vessels lead to atherothrombotic diseases such as myocardial or cerebral infarction. Thrombolytic agents are used to dissolve the already formed clots in the blood vessels; however, these drugs sometimes cause serious and fatal consequences. Herbal preparations have been used since ancient times for the treatment of several diseases although they show little toxicity in some cases. Aqueous extracts of herbs used in thrombolysis have been reported before with cytotoxic data, however, the organic extracts of herbs have not been documented. This study aims to investigate whether organic extracts possess thrombolytic properties with minimal or no toxicity. Methods An in vitro thrombolytic model was used to check the clot lysis effect of six Bangladeshi herbal extracts viz., Ageratum conyzoides L., Clausena suffruticosa, Leea indica (Burm.f. Merr., Leucas aspera Willd., Senna sophera L. Roxb., and Solanum torvum Swartz. using streptokinase as a positive control and water as a negative control. Briefly, venous blood drawn from twenty healthy volunteers was allowed to form clots which were weighed and treated with the test plant materials to disrupt the clots. Weight of clot after and before treatment provided a percentage of clot lysis. Cytotoxicity was screened by brine shrimp lethality bioassay using vincristine sulfate as positive control. Results Using an in vitro thrombolytic model, Ageratum conyzoides, Clausena suffruticosa, Leea indica, Leucas aspera, Senna sophera and Solanum torvum showed 18.12 ± 2.34%, 48.9 ± 2.44%, 39.30 ± 0.96%, 37.32 ± 2.00%, 31.61 ± 2.97% and 31.51 ± 0.57% and clot lysis respectively. Among the herbs studied Clausena suffruticosa, Leea indica and Leucas aspera showed very significant (p Ageratum conyzoides, Clausena suffruticosa, Leea indica, Leucas aspera, Senna sophera and Solanum torvum showed LC50 values 508.86 ± 6.62,41.16 ± 1.26, 2.65 ± 0.16, 181.67 ± 1.65, 233

  13. Hazard identification of contaminated sites. Ranking potential toxicity of organic sediment extracts in crustacean and fish

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, J.; Sundberg, H.; Aakerman, G.; Grunder, K.; Eklund, B.; Breitholtz, M. [Dept. of Applied Environmental Science (ITM), Stockholm Univ. (Sweden)

    2008-09-15

    Background, aim, and scope: It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment. To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those sites that are in greatest need of remediation. In most European countries, this prioritization process has almost exclusively been based on chemical analyses of known substances; only seldom toxicity data has been considered. The main objective of the current study was therefore to develop a tool for hazard identification of sediment by ranking potential toxicity of organic sediment extracts in a crustacean and a fish. A secondary objective was to investigate the difference in potential toxicity between compounds with different polarities. Materials and methods Early life stages of the crustacean Nitocra spinipes and the fish Oncorhynchus mykiss, which represent organisms from different trophic levels (primary and secondary consumer) and with different routes of exposure (i.e. ingestion through food, diffusive uptake, and maternal transfer), were exposed to hexane and acetone fractions (semi-polar compounds) of sediment from five locations, ranging from heavily to low contaminated. Preliminary tests showed that the extracts were non-bioavailable to the crustacean when exposed via water, and the extracts were therefore loaded on silica gel. Rainbow trout embryos were exposed using nano-injection technique. Results and discussion Clear concentration-response relationships of both mortality and larval development were observed in all tests with N. spinipes. Also for rainbow trout, the observed effects (e.g., abnormality, hemorrhage, asymmetric yolk sac) followed a dose-related pattern. Interestingly, our results indicate that some of the locations contained toxic semi

  14. Lycopene overproduction and in situ extraction in organic-aqueous culture systems using a metabolically engineered Escherichia coli

    OpenAIRE

    Gallego-Jara, Julia; de Diego, Teresa; del Real, Álvaro; Écija-Conesa, Ana; Manjón, Arturo; Cánovas, Manuel

    2015-01-01

    Lycopene is an import ant compound with an increasing industrial value. However, there is still no biotechnological process to obtain it. In this study, a semi-continuous system for lycopene extraction from recombinant Escherichia coli BL21 cells is proposed. A two-phase culture mode using organic solvents was found to maximize lycopene production through in situ extraction from cells. Within the reactor, three phases were formed during the process: an aqueous phase containing the recombinant...

  15. Comparison of extracts and toxicities of organic compounds in drinking water concentrated by single and composite XAD resins.

    Science.gov (United States)

    Zhou, Xue; Xiang, Lunhui; Wu, Fenghong; Peng, Xiaoling; Xie, Hong; Wang, Jiachun; Yang, Kedi; Lu, Wenqing; Wu, Zhigang

    2013-12-01

    We compared extracts and toxicities of organic compounds (OCs) in drinking water concentrated by composite XAD-2/8 resin (mixed with an equal volume of XAD-2 and XAD-8 resins) with those extracted by single XAD-2 (non-polar) and XAD-8 (polar) resins. Drinking water was processed from raw water of the Han River and the Yangtze River in Wuhan section, China. The extraction efficiency of all resins was controlled at 30%. The types of extracted OCs were detected by gas chromatography-mass spectrometry, and the cytotoxicity and genotoxicity were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and comet assays, respectively, in human hepatoma HepG2 cells. Our results showed that XAD-2/8 extracted a larger variety of OCs, compared with XAD-8 and XAD-2. The cytotoxicity and genotoxicity of extracted OCs were in the order of XAD-8> XAD-2/8> XAD-2 at almost all tested concentrations after 24 h treatment (P < 0.05). Our findings suggest that single XAD resin selectively extracts either polar or non-polar OCs, which would lead to over- or under-estimation of the toxicity of drinking water. Nevertheless, composite resin extracts both polar and non-polar OCs, and could be utilized as a useful extraction technique to evaluate the level and toxicity of OCs in drinking water.

  16. Organ-Protective Effects of Red Wine Extract, Resveratrol, in Oxidative Stress-Mediated Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Fu-Chao Liu

    2015-01-01

    Full Text Available Resveratrol, a polyphenol extracted from red wine, possesses potential antioxidative and anti-inflammatory effects, including the reduction of free radicals and proinflammatory mediators overproduction, the alteration of the expression of adhesion molecules, and the inhibition of neutrophil function. A growing body of evidence indicates that resveratrol plays an important role in reducing organ damage following ischemia- and hemorrhage-induced reperfusion injury. Such protective phenomenon is reported to be implicated in decreasing the formation and reaction of reactive oxygen species and pro-nflammatory cytokines, as well as the mediation of a variety of intracellular signaling pathways, including the nitric oxide synthase, nicotinamide adenine dinucleotide phosphate oxidase, deacetylase sirtuin 1, mitogen-activated protein kinase, peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, hemeoxygenase-1, and estrogen receptor-related pathways. Reperfusion injury is a complex pathophysiological process that involves multiple factors and pathways. The resveratrol is an effective reactive oxygen species scavenger that exhibits an antioxidative property. In this review, the organ-protective effects of resveratrol in oxidative stress-related reperfusion injury will be discussed.

  17. Divergence of compost extract and bio-organic manure effects on lucerne plant and soil

    Directory of Open Access Journals (Sweden)

    Haiyan Ren

    2017-09-01

    Full Text Available Aim Application of organic materials into agricultural systems enhances plant growth and yields, and improves soil fertility and structure. This study aimed to examine the effects of “compost extract (CE”, a soil conditioner, and bio-organic manure (BOM on the growth of lucerne (Medicago sativa, and compare the efficiency between BOM (including numbers of microorganisms and CE (including no added microorganisms. Method A greenhouse experiment was conducted with four soil amendment treatments (control, BOM, CE and CEBOM, and was arranged in a completely randomized design with 10 replicates for each treatment. Plant biomass, nutritive value and rhizobia efficacy as well as soil characteristics were monitored. Result CE rather than BOM application showed a positive effect on plant growth and soil properties when compared with the control. Lucerne nodulation responded equally to CE addition and rhizobium inoculation. CE alone and in combination with BOM significantly increased plant growth and soil microbial activities and improved soil structure. The synergistic effects of CE and BOM indicate that applying CE and BOM together could increase their efficiency, leading to higher economic returns and improved soil health. However, CE alone is more effective for legume growth since nodulation was suppressed by nitrogen input from BOM. CE had a higher efficiency than BOM for enriching soil indigenous microorganisms instead of adding microorganisms and favouring plant nodulation.

  18. Experimental and theoretical studies on a novel helical architecture driven by hydrogen and halogen bonding interactions

    Indian Academy of Sciences (India)

    QING ZHU LIU; SHAN SHAN WANG; TENG FEI WANG; JIAN GUO LIN; XUE HAI JU; LING QIU

    2016-12-01

    A novel two-dimensional (2D), layered, helical supramolecular architecture constructed via cooperative hydrogen bond and halogen bonds was synthesized and characterized: [(BMBA)₂(TPB)]n (1) [BMBA= 3-bromo-2-methylbenzoic acid, TPB = 1,2,3,4-tetra-(4-pyridyl)-butane]. Density functional theory (DFT) calculations were carried out to investigate the nature of intermolecular interactions between BMBA and TPB. The cooperation between hydrogen bond and halogen bond in building up the open organic architecture was demonstrated elaborately. Complex 1 exhibits strong photoluminescence and high thermal stability. The nature of electronic transitions in the photoluminescent process was investigated by means of time-dependent DFT (TDDFT) calculations and molecular orbital analyses, revealing that the luminescent property of the helical supramolecular architecture of 1 was ligand-based. Periodic DFT calculations show that 1 is an electrical insulator with a band gap of 3.29 eV.

  19. Molecular Engineering of Non-Halogenated Solution-Processable Bithiazole based Electron Transport Polymeric Semiconductors

    KAUST Repository

    Fu, Boyi

    2015-04-01

    The electron deficiency and trans planar conformation of bithiazole is potentially beneficial for the electron transport performance of organic semiconductors. However, the incorporation of bithiazole into polymers through a facile synthetic strategy remains a challenge. Herein, 2,2’-bithiazole was synthesized in one step and copolymerized with dithienyldiketopyrrolopyrrole to afford poly(dithienyldiketopyrrolopyrrole-bithiazole), PDBTz. PDBTz exhibited electron mobility reaching 0.3 cm2V-1s-1 in organic field-effect transistor (OFET) configuration; this contrasts with a recently discussed isoelectronic conjugated polymer comprising an electron rich bithiophene and dithienyldiketopyrrolopyrrole, which displays merely hole transport characteristics. This inversion of charge carrier transport characteristics confirms the significant potential for bithiazole in the development of electron transport semiconducting materials. Branched 5-decylheptacyl side chains were incorporated into PDBTz to enhance polymer solubility, particularly in non-halogenated, more environmentally compatible solvents. PDBTz cast from a range of non-halogenated solvents exhibited film morphologies and field-effect electron mobility similar to those cast from halogenated solvents.

  20. Dispersive micro-solid-phase extraction of herbicides in vegetable oil with metal-organic framework MIL-101.

    Science.gov (United States)

    Li, Na; Zhang, Liyuan; Nian, Li; Cao, Bocheng; Wang, Zhibing; Lei, Lei; Yang, Xiao; Sui, Jiaqi; Zhang, Hanqi; Yu, Aimin

    2015-03-04

    Dispersive microsolid-phase extraction based on metal-organic framework has been developed and applied to the extraction of triazine and phenylurea herbicides in vegetable oils in this work. The herbicides were directly extracted with MIL-101 from diluted vegetables oils without any further cleanup. The separation and determination of herbicides were carried out on high performance liquid chromatography. The effects of experimental parameters, including volume ratio of n-hexane to oil sample, mass of MIL-101, extraction time, centrifugation time, eluting solvent, and elution time were investigated. The Student's t test was applied to evaluate the selected experimental conditions. The limits of detection for the herbicides ranged from 0.585 to 1.04 μg/L. The recoveries of the herbicides ranged from 87.3 to 107%. Our results showed that the present method is rapid, simple, and effective for extracting herbicides in vegetable oils.

  1. Contribution of microorganisms to non-extractable residue formation from biodegradable organic contaminants in soil

    Science.gov (United States)

    Nowak, K. M.; Girardi, C.; Miltner, A.; Schäffer, A.; Kästner, M.

    2012-04-01

    Biodegradation of organic contaminants in soil is actually understood as their transformation into various primary metabolites, microbial biomass, mineralisation products and non-extractable residues (NER). NER are generally considered to be composed of parent compounds or primary metabolites with hazardous potential. Up to date, however, their chemical composition remains still unclear. Studies on NER formation are limited to quantitative analyses in soils or to simple humic acids-contaminant systems. However, in the case of biodegradable organic compounds, NER may also contain microbial biomass components, e.g. fatty acids (FA) and amino acids (AA). After cell death, these biomolecules are incorporated into soil organic matter (SOM) and stabilised, ultimately forming biogenic residues which are not any more extractable. We investigated the incorporation of the 13C-label into FA and AA and their fate during biodegradation experiments in soil with isotope-labelled 2,4-dichlorophenoxyacetic acid (13C6-2,4-D) and ibuprofen (13C6-ibu) as model organic contaminants. Our study proved for the first time that nearly all NER formed from 13C6-2,4-D and 13C6-ibu in soil derived from harmless microbial biomass components stabilised in SOM. 13C-FA and 13C-AA contents in the living microbial biomass fraction decreased over time and these components were continuously incorporated into the non-living SOM pool in biotic experiments with 13C6-2,4-D and 13C6-ibu. The 13C-AA in the non-living SOM were surprisingly stable from day 32 (13C6-2,4-D) and 58 (13C6-ibu) until the end of incubation. We also studied the transformation of 13C6-2,4-D and 13C6-ibu into NER in the abiotic soil experiments. In these experiments, the total NER contents were much lower than in the corresponding biotic experiments. The absence of labelled biomolecules in the NER fraction in abiotic soils demonstrated that they consist of the potentially hazardous parent compounds and / or their metabolites. Biogenic

  2. Grape skin extract mitigates tissue degeneration, genotoxicity, and oxidative status in multiple organs of rats exposed to cadmium.

    Science.gov (United States)

    Boiago Gollucke, Andrea P; Claudio, Samuel R; Yamamura, Hirochi; Morais, Damila R; Bataglion, Giovana A; Eberlin, Marcos N; Aguiar, Odair; Ribeiro, Daniel A

    2016-07-28

    The aim of this study was to investigate whether grape skin extract can mitigate the noxious activities induced by cadmium exposure in multiple organs of rats. For this purpose, histopathological analysis for the liver, genotoxicity, and oxidative status in the blood and liver were investigated in this setting. A total of 20 Wistar rats weighing 250 g, on average, and 8 weeks of age were distributed into four groups (n=5) as follows: control group (nontreated group); cadmium group (Cd); and grape skin extract groups (Cd+GS) at 175 or 350 mg/l. Histopathological analysis in liver showed that animals treated with grape skin extract showed improved tissue degeneration induced by cadmium intoxication. Genetic damage was reduced in blood and hepatocytes as indicated by comet and micronucleus assays in animals treated with grape skin extract. Copper-zinc superoxide dismutase and cytochrome c gene expression increased in groups treated with grape skin extract in liver cells. Grape skin extract also reduced the 8-hydroxy-2'-deoxyguanosine levels in liver cells compared with the cadmium group. Taken together, our results indicate that grape skin extract can mitigate tissue degeneration, genotoxicity, and oxidative stress induced by cadmium exposure in multiple organs of Wistar rats.

  3. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  4. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  5. Comparative study of lipid extraction from microalgae by organic solvent and supercritical CO2.

    Science.gov (United States)

    Cheng, Chen-Hsi; Du, Tz-Bang; Pi, Hsien-Chueh; Jang, Shyue-Ming; Lin, Yun-Huin; Lee, Hom-Ti

    2011-11-01

    Pavlova sp. was employed to evaluate the efficiency of different lipid extraction methods. The microalgal crude lipids content determined using the mixed solvent with ultrasonic method was 44.7 wt.%. The triglyceride content obtained by the mixed solvent method was 15.6 wt.%. The extraction yield was the FAME yield divided by the maximum FAME (15.9 wt.%). The extraction yield was improved by cell disruption prior to extraction, and the highest triglyceride extraction yield of 98.7% was observed using the supercritical fluid extraction (SFE) method with bead-beating. The results indicate that the SFE method is effective and provides higher selectivity for triglyceride extraction though the total lipid extracted was less than that using solvent extraction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Comparison of graphene oxide with reduced graphene oxide as hole extraction layer in organic photovoltaic cells.

    Science.gov (United States)

    Choi, Kyoung Soon; Park, Yensil; Kim, Soo Young

    2013-05-01

    A comparison was performed between the use of graphene oxide (GO) and reduced graphene oxide (rGO) as a hole extraction layer (HEL) in organic photovoltaic (OPV) cells with poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester. Hydrazine hydrate (HYD) and the thermal method (Thermal) were adopted to change the GO to rGO. The GO HEL was deposited on an indium tin oxide electrode by spin coating, followed by the reduction process to form the rGO HELs. The success of the reduction processes was confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoemission spectroscopy, transmittance, and 2-point probe method. The OPV cell with the GO (-3 nm) HEL exhibits an increased power conversion efficiency (PCE) as high as 2.5% under 100 mW/cm2 illumination under air mass conditions, which is higher than that of the OPV cell without HEL, viz. 1.78%. However, the PCE of the OPV cell with rGO HEL is not high as the values of 1.8% for the HYD-rGO and 1.9% for the Thermal-rGO. The ultraviolet photoemission spectroscopy results showed that the work function of GO was 4.7 eV, but those of HYD-rGO and Thermal-rGO were 4.2 eV and 4.5 eV, respectively. Therefore, it is considered that GO is adequate to extract the holes from the active layer, but HYD-rGO and Thermal-rGO are not appropriate to use as HELs in OPV cells from the viewpoint of the energy alignment.

  7. Importance of reactive halogens in the tropical marine atmosphere using WRF-chem

    Science.gov (United States)

    Badia, Alba; Reeves, Claire E.; Baker, Alex; Volkamer, Rainer; Apel, Eric; Saiz-Lopez, Alfonso; von Glasow, Roland

    2017-04-01

    Halogen species (chlorine, bromine and iodine) are known to play an important role in the chemistry and oxidizing capacity of the troposphere, particularly in the marine boundary layer (MBL). Reactive halogens participate in catalytic reaction cycles that efficiently destroy O3, change the HOX and NOX partitioning, affect the oxidation of volatile organic compounds (VOCs) and mercury, reduce the lifetime of methane, and take part in new particle formation. Numerical models predicted that reactive halogen compounds account for 30% of O3 destruction in the MBL and 5-20% globally. Up to 34% of O3 loss in the tropical East Pacific is due to I and Br combined. Recent studies have highlighted the key role that heterogeneous chemistry plays in explaining observations of BrO and IO abundances in the tropical troposphere. The main objective of this study is to investigate the atmospheric chemistry in the tropical East Pacific with a focus on reactive halogens using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and field data from the TORERO campaign. Our reaction mechanism in WRF-Chem is based on the MOZART mechanism and has been extended to include bromine, chlorine and iodine chemistry. Heterogeneous recycling reactions involving sea-salt aerosol and other particles have been included into the model, along with oceanic emissions of important OVOCs and halocarbons. Sea surface emissions of inorganic iodine are calculated using the parameterisation of Carpenter et al., 2013. Focusing on TORERO observations from the ships and a selected number of flights we present the tropospheric impacts of halogens (BrO, IO) in the tropospheric chemistry of relevant species (O3, OH and OVOCS). Sensitivity runs are made in order to study the impact of heterogeneous chemistry in the iodine and bromine species partitioning. A comparison between the online calculation of Very Short Lived Halocarbons (VSLH) oceanic emissions with prescribed oceanic emissions is

  8. Double-bed-type extraction needle packed with activated-carbon-based sorbents for very volatile organic compounds.

    Science.gov (United States)

    Ueta, Ikuo; Samsudin, Emi Liana; Mizuguchi, Ayako; Takeuchi, Hayato; Shinki, Takumi; Kawakubo, Susumu; Saito, Yoshihiro

    2014-01-01

    A novel needle-type sample preparation device was developed for the determination of very volatile organic compounds (VVOCs) in gaseous samples by gas chromatography-mass spectrometry (GC-MS). Two types of activated-carbon-based sorbents, Carbopack X and a carbon molecular sieve (CMS), were investigated as the extraction medium. A double-bed-type extraction needle showed successful extraction and desorption performance for all investigated VVOCs, including acetaldehyde, isoprene, pentane, acetone, and ethanol. Sensitive and reliable determination of VVOCs was achieved by systematically optimizing several desorption conditions. In addition, the effects of sample humidity on the extraction and desorption of analytes were investigated with the needle-type extraction devices. Only the CMS packed extraction needle was adversely affected by sample humidity during the desorption process; on the other hand the double-bed-type extraction needle was unaffected by sample humidity. Finally, the developed double-bed-type extraction needle was successfully applied to the analysis of breath VVOCs of healthy subjects.

  9. Some extractable iron contents as influenced by some organic manures application in the soils of Lake Geriyo, Adamawa state, Nigeria

    Directory of Open Access Journals (Sweden)

    Saddiq Abdullahi Muhammad

    2016-04-01

    Full Text Available Organic manures are safer sources of plant nutrients and a good source of micronutrients therefore; pot experiments were carried out to estimate some extractable iron contents as influenced by organic manure application in the soils of Lake Geriyo, Adamawa state, Nigeria. Two types of organic manures; poultry droppings, cow dung and control were used for the experiment. Three levels of organic manures; 5, 10 and 15 tons per hectare (ton ha-1 and three sampling time (30, 60 and 90 DAS were laid down in a completely randomized (CRD design replicated three times. Results obtained revealed that rate, type of organic manures and time of submergence significantly (P ≤ 0.05 changed Fe content in the soil. Mean extractable iron concentrations of 42.01, 56.13 and 24.63 mgkg-1 were recorded for ammonium oxalate extractable iron, Citrate Bicarbonate Dithionite extractable iron and sodium pyrophosphate extractable iron in the first experiment while 45.81, 59.29 and 28.89 mgkg-1 were recorded for the second experiment respectively. However, CBD which extracts both amorphous and crystalline Fe recorded the highest Fe contents throughout the treatments with poultry droppings applied pots recording superior values than that of cowdung manure. similarly, higher values of oxa-Fe and Pyro-Fe were recorded in both manures compared to the control. In conclusion poultry droppings may result in iron accumulation and toxicity hence should be used with caution in the soil of Lake Geriyo and similar soils to avoid serious soil reduction leading to iron toxicity and soil phosphorus antagonism.

  10. Adsorption of halogenated aliphatic contaminants by graphene nanomaterials.

    Science.gov (United States)

    Zhou, Yang; Apul, Onur Guven; Karanfil, Tanju

    2015-08-01

    In this study, adsorption of ten environmentally halogenated aliphatic synthetic organic compounds (SOCs) by a pristine graphene nanosheet (GNS) and a reduced graphene oxide (rGO) was examined, and their adsorption behaviors were compared with those of a single-walled carbon nanotube (SWCNT) and a granular activated carbon (GAC). In addition, the impacts of background water components (i.e., natural organic matter (NOM), ionic strength (IS) and pH) on the SOC adsorption behavior were investigated. The results indicated HD3000 and SWCNT with higher microporous volumes exhibited higher adsorption capacities for the selected aliphatic SOCs than graphenes, demonstrating microporosity of carbonaceous adsorbents played an important role in the adsorption. Analysis of adsorption isotherms demonstrated that hydrophobic interactions were the dominant contributor to the adsorption of aliphatic SOCs by graphenes. However, π-π electron donor-acceptor and van der Waals interactions are likely the additional mechanisms contributing to the adsorption of aliphatic SOCs on graphenes. Among the three background solution components examined, NOM showed the most influential effect on adsorption of the selected aliphatic SOCs, while pH and ionic strength had a negligible effects. The NOM competition on aliphatic adsorption was less pronounced on graphenes than SWCNT. Overall, in terms of adsorption capacities, graphenes tested in this study did not exhibit a major advantage over SWCNT and GAC for the adsorption of aliphatic SOCs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Organic metamorphism in the California petroleum basins; Chapter B, Insights from extractable bitumen and saturated hydrocarbons

    Science.gov (United States)

    Price, Leigh C.

    2000-01-01

    Seventy-five shales from the Los Angeles, Ventura, and Southern San Joaquin Valley Basins were extracted and analyzed. Samples were chosen on the basis of ROCK-EVAL analyses of a much larger sample base. The samples ranged in burial temperatures from 40 ? to 220 ? C, and contained hydrogen-poor to hydrogen-rich organic matter (OM), based on OM visual typing and a correlation of elemental kerogen hydrogen to carbon ratios with ROCK-EVAL hydrogen indices. By extractable bitumen measurements, rocks with hydrogen- poor OM in the Los Angeles Basin began mainstage hydrocarbon (HC) generation by 90 ? C. The HC concentrations maximized by 165 ? C, and beyond 165 ? C, HC and bitumen concentrations and ROCK-EVAL hydrogen indices all began decreasing to low values reached by 220 ? C, where HC generation was largely complete. Rocks with hydrogen-poor OM in the Southern San Joaquin Valley Basin commenced mainstage HC generation at 135 ? C and HC concentrations maximized by 180 ? C. Above 180 ? C, HC and bitumen concentrations and ROCK-EVAL hydrogen indices all decreased to low values reached by 214 ? C, again the process of HC generation being largely complete. In both cases, bell-shaped HC-generation curves were present versus depth (burial temperature). Mainstage HC generation had not yet begun in Ventura Basin rocks with hydrogen-poor OM by 140 ? C. The apparent lower temperature for initiation of mainstage generation in the Los Angeles Basin is attributed to very recent cooling in that basin from meteoric-water flow. Thus, HC generation there most probably occurred at higher burial temperatures. In contrast, mainstage HC generation, and all aspects of organic metamorphism, were strongly suppressed in rocks with hydrogen-rich OM at temperatures as high as 198 ? C. For example, shales from the Wilmington field (Los Angeles Basin) from 180 ? to 198 ? C retained ROCK-EVAL hydrogen indices of 550- 700 and had saturated-HC coefficients of only 4-15 mg/g organic carbon. The rocks

  12. Halogenated coumarin derivatives as novel seed protectants.

    Science.gov (United States)

    Brooker, N; Windorski, J; Bluml, E

    2008-01-01

    Development of new and improved antifungal compounds that are target-specific is backed by a strong Federal, public and commercial mandate. Many plant-derived chemicals have proven fungicidal properties, including the coumarins (1,2-Benzopyrone) found in a variety of plants such as clover, sweet woodruff and grasses. Preliminary research has shown the coumarins to be a highly active group of molecules with a wide range of antimicrobial activity against both fungi and bacteria. It is believed that these cyclic compounds behave as natural pesticidal defence molecules for plants and they represent a starting point for the exploration of new derivative compounds possessing a range of improved antifungal activity. Within this study, derivatives of coumarin that were modified with halogenated side groups were screened for their antifungal activity against a range of soil-borne plant pathogenic fungi. Fungi included in this in vitro screen included Macrophomina phaseolina (charcoal rot), Phytophthora spp. (damping off and seedling rot), Rhizoctonia spp. (damping off and root rot) and Pythium spp. (seedling blight), four phylogenetically diverse and economically important plant pathogens. Studies indicate that these halogenated coumarin derivatives work very effectively in vitro to inhibit fungal growth and some coumarin derivatives have higher antifungal activity and stability as compared to the original coumarin compound alone. The highly active coumarin derivatives are brominated, iodinated and chlorinated compounds and results suggest that besides being highly active, very small amounts can be used to achieve LD100 rates. In addition to the in vitro fungal inhibition assays, results of polymer seed coating compatibility and phytotoxicity testing using these compounds as seed treatments will also be reported. These results support additional research in this area of natural pesticide development.

  13. Organic Extractives from Mentha spp. Honey and the Bee-Stomach: Methyl Syringate, Vomifoliol, Terpenediol I, Hotrienol and Other Compounds

    Directory of Open Access Journals (Sweden)

    Igor Jerković

    2010-04-01

    Full Text Available The GC and GC/MS analyses of the solvent organic extractive from the stomach of the bees, having collected Mentha spp. nectar, revealed the presence of methyl syringate (6.6%, terpendiol I (5.0% and vomifoliol (3.0% that can be attributed to the plant origin. Other major compounds from the bee-stomach were related to the composition of cuticular waxes and less to pheromones. Organic extractivesfrom Mentha spp. honey were obtained by solvent-free headspace solid-phase microextraction (HS-SPME and ultrasonic solvent extraction (USE and analyzed by GC and GC/MS. The major honey headspace compounds were hotrienol (31.1%–38.5%, 2-methoxy-4-methylphenol (0.5–6.0%, cis- and trans-linalool oxides (0.9–2.8%, linalool (1.0–3.1% and neroloxide (0.9–1.9%. Methyl syringate was the most abundant compound (38.3-56.2% in the honey solvent extractives followed by vomifoliol (7.0–26.6%. Comparison of the honey organic extractives with the corresponding bee-stomach extractive indicated that methyl syringate and vomofoliol were transferred to the honey while terpendiol I was partially transformed to hotrienol in ripened honey.

  14. A box model study on photochemical interactions between VOCs and reactive halogen species in the marine boundary layer

    Directory of Open Access Journals (Sweden)

    K. Toyota

    2004-01-01

    Full Text Available A new chemical scheme is developed for the multiphase photochemical box model SEAMAC (size-SEgregated Aerosol model for Marine Air Chemistry to investigate photochemical interactions between volatile organic compounds (VOCs and reactive halogen species in the marine boundary layer (MBL. Based primarily on critically evaluated kinetic and photochemical rate parameters as well as a protocol for chemical mechanism development, the new scheme has achieved a near-explicit description of oxidative degradation of up to C3-hydrocarbons (CH4, C2H6, C3H8, C2H4, C3H6, and C2H2 initiated by reactions with OH radicals, Cl- and Br-atoms, and O3. Rate constants and product yields for reactions involving halogen species are taken from the literature where available, but the majority of them need to be estimated. In particular, addition reactions of halogen atoms with alkenes will result in forming halogenated organic intermediates, whose photochemical loss rates are carefully evaluated in the present work. Model calculations with the new chemical scheme reveal that the oceanic emissions of acetaldehyde (CH3CHO and alkenes (especially C3H6 are important factors for regulating reactive halogen chemistry in the MBL by promoting the conversion of Br atoms into HBr or more stable brominated intermediates in the organic form. The latter include brominated hydroperoxides, bromoacetaldehyde, and bromoacetone, which sequester bromine from a reactive inorganic pool. The total mixing ratio of brominated organic species thus produced is likely to reach 10-20% or more of that of inorganic gaseous bromine species over wide regions over the ocean. The reaction between Br atoms and C2H2 is shown to be unimportant for determining the degree of bromine activation in the remote MBL. These results imply that reactive halogen chemistry can mediate a link between the oceanic emissions of VOCs and the behaviors of compounds that are sensitive to halogen chemistry such as dimethyl

  15. Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost

    Energy Technology Data Exchange (ETDEWEB)

    Scaglia, Barbara, E-mail: barbara.scaglia@unimi.it [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy); Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira [Laboratório de Química Ambiental, Universidade de São Paulo, Instituto de Química de São Carlos, Avenida Trabalhador São Carlense, 400, São Carlos (Brazil); Tambone, Fulvia [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy); Adani, Fabrizio, E-mail: fabrizio.adani@unimi.it [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy)

    2016-08-15

    This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100–6000 mg carbon L{sup −1}. {sup 13}C CPMAS-NMR and GC–MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS {sup 13}CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R{sup 2} = − 0.85; p < 0.01, n = 6). - Highlights: • Vermicomposting converts waste into organic fertilizer. • Vermicomposts can have biostimulating effect for the presence of hormone-like molecules. • Auxine-like activity was associated to the vermicompost humic acid fraction (HA). • HA carboxylic acids and amino acids, were reported to act as auxin-like molecules. • A linear regression was found between molecules and auxin-like activity.

  16. In vitro thyroid disrupting effects of organic extracts from WWTPs in Beijing

    Institute of Scientific and Technical Information of China (English)

    Na Li; Mei Ma; Kaifeng Rao; Zijian Wang

    2011-01-01

    It is generally known that there are many endocrine disrupting compounds (EDCs) in the effluents from wastewater treatment plants (WWTPs). Most research has focused on the occurrence of estrogenic or androgenic activities, while ignoring that there are environmental chemicals disrupting thyroid system, which is essential for growth and development in both humans and animals. In the present work, a two-hybrid yeast assay was conducted to evaluate the removal efficiencies of agonistic or antagonistic thyroid receptor (TR) mediated effects in different treatment processes of three WWTPs located in Beijing. We found no TR agonistic, but TR antagonistic activities in all processes from the WWTPs. The TR antagonistic activities in organic extracts of water samples were then calibrated regarding to a known TR-inhibitor, amiodarone hydrochloride (AH). The observed concentration of TR disrupting substances ranged from 2.35 × 10-8 to 6.19 × 10-7 mol/L AH in Gaobeidian WWTP, 3.76 × 10-8 to 8.75 × 10-8 mol/L AH in Lugouqiao WWTP,and 4.80 × 10-9 to 2.55 × 10-8 mol/L AH in Beixiaohe WWTP. Of the three WWTPs, the removal rates were 92.7%, 42.2%, and 23.1% respectively. Industrial sewage may contain more TR disrupting substances compared with domestic sewage. The recipient waters were found to contain considerable concentrations of TR disrupting substances that may cause adverse effects on the exposed organisms.

  17. A New Halogenated Biindole and A New Apo-carotenone from Green Alga Chaetomorpha basiretorsa Setchell

    Institute of Scientific and Technical Information of China (English)

    Da Yong SHI; Li Jun HAN; Jie SUN; Shuai LI; Su Juan WANG; Yong Chun YANG; Xiao FAN; Jian Gong SHI

    2005-01-01

    A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi- 1H-indole and l ′S*,4′R*-8-(4′-hydroxy-2′,6′,6′-trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.

  18. Critical-fluid extraction of organics from water. Volume II. Experimental. Final report, 1 October 1979-30 November 1983

    Energy Technology Data Exchange (ETDEWEB)

    Abboud, O.K.; de Filippi, R.P.; Goklen, K.E.; Moses, J.M.

    1984-06-01

    Critical fluid extraction has been tested at the pilot plant scale as a method of separating organics from water. The process employed resembles a liquid-liquid extraction in which the solvent is near-critical carbon dioxide and the feed is an organic in aqueous solution. Carbon dioxide's solvent and other thermodynamic properties, and the effective utilization of a vapor recompression cycle in the process design have significantly reduced the energy required for these separations. This process is an energy-conserving alternative to the distillation processes which are currently employed. The objectives of this portion of the project were to demonstrate the feasibility of this technology and to gather the engineering data required to evaluate the process. Three alcohols were tested in these experiments - ethanol, isopropanol and sec-butanol - and were all successfully extracted.

  19. Simultaneous Separation of Manganese, Cobalt, and Nickel by the Organic-Aqueous-Aqueous Three-Phase Solvent Extraction

    Science.gov (United States)

    Shirayama, Sakae; Uda, Tetsuya

    2016-04-01

    This research outlines an organic-aqueous-aqueous three-phase solvent extraction method and proposes its use in a new metal separation process for the recycling of manganese (Mn), cobalt (Co), and nickel (Ni) from used lithium ion batteries (LIBs). The three-phase system was formed by mixing xylene organic solution, 50 pct polyethylene glycol (PEG) aqueous solution, and 1 mol L-1 sodium sulfate (Na2SO4) aqueous solution. The xylene organic solution contained 2-ethylhexylphosphonic acid (D2EHPA) as an extractant for Mn ion, and the Na2SO4 aqueous solution contained 1 mol L-1 potassium thiocyanate (KSCN) as an extractant for Co ion. Concentrations of the metal ions were varied by dissolving metal sulfates in the Na2SO4 aqueous solution. As a result of the experiments, Mn, Co, and Ni ions were distributed in the xylene organic phase, PEG-rich aqueous phase, and Na2SO4-rich aqueous phase, respectively. The separation was effective when the pH value was around 4. Numerical simulation was also conducted in order to predict the distribution of metal ions after the multi-stage counter-current extractions.

  20. Extraction and [superscript 1]H NMR Analysis of Fats from Convenience Foods: A Laboratory Experiment for Organic Chemistry

    Science.gov (United States)

    Hartel, Aaron M.; Moore, Amy C.

    2014-01-01

    The extraction and analysis of fats from convenience foods (crackers, cookies, chips, candies) has been developed as an experiment for a second-year undergraduate organic chemistry laboratory course. Students gravimetrically determine the fat content per serving and then perform a [superscript 1]H NMR analysis of the recovered fat to determine the…

  1. Extraction and [superscript 1]H NMR Analysis of Fats from Convenience Foods: A Laboratory Experiment for Organic Chemistry

    Science.gov (United States)

    Hartel, Aaron M.; Moore, Amy C.

    2014-01-01

    The extraction and analysis of fats from convenience foods (crackers, cookies, chips, candies) has been developed as an experiment for a second-year undergraduate organic chemistry laboratory course. Students gravimetrically determine the fat content per serving and then perform a [superscript 1]H NMR analysis of the recovered fat to determine the…

  2. Pyrolysis-gas chromatography/mass spectrometry of soil organic matter extracted from a Brazilian mangrove and Spanish salt marshes

    NARCIS (Netherlands)

    Perobelli Ferreira, F.; Buurman, P.; Macias, F.; Otero, X.L.; Boluda, R.

    2009-01-01

    The soil organic matter (SOM) extracted under different vegetation types from a Brazilian mangrove (Pai Matos Island, São Paulo State) and from three Spanish salt marshes (Betanzos Ría and Corrubedo Natural Parks, Galícia, and the Albufera Natural Park, Valencia) was investigated by pyrolysis-gas ch

  3. Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost.

    Science.gov (United States)

    Scaglia, Barbara; Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira; Tambone, Fulvia; Adani, Fabrizio

    2016-08-15

    This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100-6000mgcarbonL(-1). (13)C CPMAS-NMR and GC-MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS (13)CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R(2)=-0.85; p<0.01, n=6).

  4. Antipoliovirus Activity of the Organic Extract of Eupatorium buniifolium: Isolation of Euparin as an Active Compound

    Directory of Open Access Journals (Sweden)

    María Florencia Visintini Jaime

    2013-01-01

    Full Text Available The antiviral activity of the organic extract (OE of Eupatorium buniifolium against poliovirus type 1 was determined by in vitro assays with an effective concentration 50 (EC50 of 23.3 ± 3.3 µg/mL. Bioassay-guided fractionation of the OE allowed the isolation of an active principle that was identified by spectroscopic methods (1H- and 13C-NMR, EI-MS, UV, and IR spectroscopy as the benzofuran euparin. The plaque reduction assay in Vero cells was used to assess the antiviral activity of euparin against poliovirus types 1, 2, and 3 with EC50 values of 0.47, 0.12, and 0.15 µg/mL, respectively. Moreover, this compound showed high selectivity indexes of 284.9, 1068, and 854.7, respectively. In order to identify the mechanism by which euparin exerts its antiviral activity, the virucidal effect, the pretreatment of Vero cells, and the time of action on one viral replication cycle were evaluated. Results obtained demonstrated that euparin exerts its effect during the early events of the replication cycle, from the virus adsorption to cells up to the first twenty minutes after infection. This is the first report on the presence of euparin in E. buniifolium and its antiviral activity.

  5. A silver-free, reflective substrate electrode for electron extraction in top-illuminated organic photovoltaics.

    Science.gov (United States)

    Tyler, Martin S; Hutter, Oliver S; Walker, Marc; Hatton, Ross A

    2015-04-27

    The choice of metals suitable as the reflective substrate electrode for top-illuminated organic photovoltaics (OPVs) is extremely limited. Herein, we report a novel substrate electrode for this class of OPV architecture based on an Al | Cu | AlOx triple-layer structure, which offers a reflectivity comparable to that of Al over the wavelength range 400-900 nm, a work function suitable for efficient electron extraction in OPVs and high stability towards oxidation. In addition to demonstrating the advantage of this composite electrode over Al in model top-illuminated OPVs, we also present the results of a photoelectron spectroscopy study, which show that an oxidised 0.8 nm Al layer deposited by thermal evaporation onto an Al | Cu reflective substrate electrode is sufficient to block oxidation of the underlying Cu by air or during deposition of a ZnO1-x electron-transport layer. This is remarkable given that the self-limiting oxide thickness on Al metal is greater than 2 nm.

  6. Interpretation of fingerprint image quality features extracted by self-organizing maps

    Science.gov (United States)

    Danov, Ivan; Olsen, Martin A.; Busch, Christoph

    2014-05-01

    Accurate prediction of fingerprint quality is of significant importance to any fingerprint-based biometric system. Ensuring high quality samples for both probe and reference can substantially improve the system's performance by lowering false non-matches, thus allowing finer adjustment of the decision threshold of the biometric system. Furthermore, the increasing usage of biometrics in mobile contexts demands development of lightweight methods for operational environment. A novel two-tier computationally efficient approach was recently proposed based on modelling block-wise fingerprint image data using Self-Organizing Map (SOM) to extract specific ridge pattern features, which are then used as an input to a Random Forests (RF) classifier trained to predict the quality score of a propagated sample. This paper conducts an investigative comparative analysis on a publicly available dataset for the improvement of the two-tier approach by proposing additionally three feature interpretation methods, based respectively on SOM, Generative Topographic Mapping and RF. The analysis shows that two of the proposed methods produce promising results on the given dataset.

  7. Embryotoxicity of organic extracts from airborne particulates in ambient air in the chicken embryo

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, H.; Kashimoto, T.

    1986-07-01

    A fraction containing polycyclic aromatic hydrocarbons (PAHs), prepared from an organic extract of airborne particulate matter, was separated into nine subfractions by high pressure liquid chromatography (HPLC). The embryotoxicity of each of these fractions was investigated and analysis for PAHs by capillary gas chromatography-mass spectrometry (GC-MS) was performed. The ninth subfraction, with coronene as its main component, had the strongest toxic effects on chicken embryos per m/sup 3/ of air. Of the remaining eight subfractions, three had the greatest toxicity: the second fraction with benzofluoranthenes and benzo(e)pyrene as the main components, the fourth fraction having PAH-estimated compounds in small amounts, and the fifth fraction with indeno(1,2,3-cd)pyrene and benzo(ghi)perylene as the main ingredients had the greatest toxicity. These findings indicate PAHs to be responsible for embryotoxicity but the total amounts were not necessarily proportional to it. For further characterization of toxicity, the effects of each PAH and/or quantification of other embryotoxic compounds possibly present in small amounts should be investigated.

  8. The Halogenated Metabolism of Brown Algae (Phaeophyta, Its Biological Importance and Its Environmental Significance

    Directory of Open Access Journals (Sweden)

    Stéphane La Barre

    2010-03-01

    Full Text Available Brown algae represent a major component of littoral and sublittoral zones in temperate and subtropical ecosystems. An essential adaptive feature of this independent eukaryotic lineage is the ability to couple oxidative reactions resulting from exposure to sunlight and air with the halogenations of various substrates, thereby addressing various biotic and abiotic stresses i.e., defense against predators, tissue repair, holdfast adhesion, and protection against reactive species generated by oxidative processes. Whereas marine organisms mainly make use of bromine to increase the biological activity of secondary metabolites, some orders of brown algae such as Laminariales have also developed a striking capability to accumulate and to use iodine in physiological adaptations to stress. We review selected aspects of the halogenated metabolism of macrophytic brown algae in the light of the most recent results, which point toward novel functions for iodide accumulation in kelps and the importance of bromination in cell wall modifications and adhesion properties of brown algal propagules. The importance of halogen speciation processes ranges from microbiology to biogeochemistry, through enzymology, cellular biology and ecotoxicology.

  9. Lycopene overproduction and in situ extraction in organic-aqueous culture systems using a metabolically engineered Escherichia coli.

    Science.gov (United States)

    Gallego-Jara, Julia; de Diego, Teresa; Del Real, Álvaro; Écija-Conesa, Ana; Manjón, Arturo; Cánovas, Manuel

    2015-12-01

    Lycopene is an import ant compound with an increasing industrial value. However, there is still no biotechnological process to obtain it. In this study, a semi-continuous system for lycopene extraction from recombinant Escherichia coli BL21 cells is proposed. A two-phase culture mode using organic solvents was found to maximize lycopene production through in situ extraction from cells. Within the reactor, three phases were formed during the process: an aqueous phase containing the recombinant E. coli, an interphase, and an organic phase. Lycopene was extracted from the cells to both the interphase and the organic phase and, consequently, thus enhancing its production. Maximum lycopene production (74.71 ± 3.74 mg L(-1)) was obtained for an octane-aqueous culture system using the E. coli BL21LF strain, a process that doubled the level obtained in the control aqueous culture. Study of the interphase by transmission electron microscopy (TEM) showed the proteo-lipidic nature and the high storage capacity of lycopene. Moreover, a cell viability test by flow cytometry (CF) after 24 h of culture indicated that 24 % of the population could be re-used. Therefore, a batch series reactor was designed for semi-continuous lycopene extraction. After five cycles of operation (120 h), lycopene production was similar to that obtained in the control aqueous medium. A final specific lycopene yield of up to 49.70 ± 2.48 mg g(-1) was reached at 24 h, which represents to the highest titer to date. In conclusion, the aqueous-organic semi-continuous culture system proposed is the first designed for lycopene extraction, representing an important breakthrough in the development of a competitive biotechnological process for lycopene production and extraction.

  10. Optimization of microwave-assisted extraction for six inorganic and organic arsenic species in chicken tissues using response surface methodology.

    Science.gov (United States)

    Zhang, Wenfeng; Hu, Yuanan; Cheng, Hefa

    2015-09-01

    Response surface methodology was applied to optimize the parameters for microwave-assisted extraction of six major inorganic and organic arsenic species (As(III), As(V), dimethyl arsenic acid, monomethyl arsenic acid, p-arsanilic acid, and roxarsone) from chicken tissues, followed by detection using a high-performance liquid chromatography with inductively coupled mass spectrometry detection method, which allows the simultaneous analysis of both inorganic and organic arsenic species in the extract in a single run. Effects of extraction medium, solution pH, liquid-to-solid ratio, and the temperature and time of microwave-assisted extraction on the extraction of the targeted arsenic species were studied. The optimum microwave-assisted extraction conditions were: 100 mg of chicken tissue, extracted by 5 mL of 22% v/v methanol, 90 mmol/L (NH4 )2 HPO4 , and 0.07% v/v trifluoroacetic acid (with pH adjusted to 10.0 by ammonium hydroxide solution), ramping for 10 min to 71°C, and holding for 11 min. The method has good extraction performance for total arsenic in the spiked and nonspiked chicken tissues (104.0 ± 13.8% and 91.6 ± 7.8%, respectively), except for the ones with arsenic contents close to the quantitation limits. Limits of quantitation (S/N = 10) for As(III), As(V), dimethyl arsenic acid, monomethyl arsenic acid, p-arsanilic acid, and roxarsone in chicken tissues using this method were 0.012, 0.058, 0.039, 0.061, 0.102, and 0.240 mg/kg (dry weight), respectively.

  11. Simultaneous extraction and cleanup of high-lipid organs from white sturgeon (Acipenser transmontanus) for multiple legacy and emerging organic contaminants using QuEChERS sample preparation.

    Science.gov (United States)

    Morrison, Shane A; Sieve, Kristal K; Ratajczak, Robert E; Bringolf, Robert B; Belden, Jason B

    2016-01-01

    The objective of this research was to utilize the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method to extract a broad range of persistent organic pollutants from sturgeon organs (liver and gonad) as indicators of exposure. The analyte list was prioritized to include carcinogenic polyaromatic hydrocarbons (PAHs), the most commonly occurring polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), persistent bioaccumulative and toxic chemicals (PBTs), and emergent contaminants of concern (ECCs) as indicators of human sewage exposure. White sturgeon (Acipenser transmontanus) were selected for this study to support a larger ecotoxicological study to monitor contaminants as an assessment of fish health. Organ tissues contained high lipid content with percentages of 15% and 34% for liver and gonad, respectively. Overall recoveries from fortified sturgeon tissues were high, 71-98% for PAHs, 60-107% for PBDEs and PCBs, 86-107% for PBT chemicals, and 88-107% for ECCs with the exception of octinoxate (28%) from liver tissues. Analyte recovery trends decreased as analyte lipophilicity and molecular weight increased. These recoveries demonstrate that extraction using QuEChERS can be used for screening of the most common bioaccumulating organic compounds in high lipid fish tissue using a single extraction and analysis.

  12. Removal of organic contaminants from water or wastewater with liquefied gases

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This study utilized liquefied gases (LG) as extractant to remove various organic contaminants including halogenated hydrocarbons and phenols as well as aromatic compounds from aqueousmatrices. Orthogonal experiments were performed to optimize theoperating conditions such as temperature, co-solvents and so on.Under favorable conditions, high removal efficiencies can bereadily achieved for a great number of representative model organiccontaminants, the removal efficiencies for most of the hydrophobiccontaminants were greater than 90% in a single extraction stage.Tentative effort was also done for the removal of extractedcontaminants from recycled liquefied gases.

  13. Weak acidity of vinyl CH bonds enhanced by halogen substitution.

    Science.gov (United States)

    Craig, Norman C; Matlin, Albert R

    2014-02-21

    As shown by the rates of proton-deuteron exchange in ethylenes with halogen substituents, the weak acidity of vinyl CH bonds is enhanced by halogen substitution. Relative rates of exchange in basic deuterium oxide reflect the relative acidities. Substitution in the α position has the strongest effect. Less electronegative halogens such as bromine increase the acidity more than does fluorine. The vinyl CH acid strengths correlate closely with the energies of deprotonation of isolated molecules into isolated anions, as computed with the MP2/cc-pVQZ model. The smaller deprotonation energies are associated with the stronger acids. Atomic charges from a natural bond order analysis done with the MP2/aug-cc-pVQZ model show that the negative charge becomes more dispersed in the anions of the stronger acids. Results are given for 13 haloethylenes and for 6 halogen-substituted butadienes, cyclopropenes, and a cyclobutene.

  14. Halogen Bonding Promotes Higher Dye-Sensitized Solar Cell Photovoltages.

    Science.gov (United States)

    Simon, Sarah J C; Parlane, Fraser G L; Swords, Wesley B; Kellett, Cameron W; Du, Chuan; Lam, Brian; Dean, Rebecca K; Hu, Ke; Meyer, Gerald J; Berlinguette, Curtis P

    2016-08-24

    We report here an enhancement in photovoltage for dye-sensitized solar cells (DSSCs) where halogen-bonding interactions exist between a nucleophilic electrolyte species (I(-)) and a photo-oxidized dye immobilized on a TiO2 surface. The triarylamine-based dyes under investigation showed larger rate constants for dye regeneration (kreg) by the nucleophilic electrolyte species when heavier halogen substituents were positioned on the dye. The open-circuit voltages (VOC) tracked these kreg values. This analysis of a homologous series of dyes that differ only in the identity of two halogen substituents provides compelling evidence that the DSSC photovoltage is sensitive to kreg. This study also provides the first direct evidence that halogen-bonding interactions between the dye and the electrolyte can bolster DSSC performance.

  15. UARS Halogen Occultation Experiment (HALOE) Level 2 V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The HALOE home page on the WWW is http://haloe.gats-inc.com/home/index.php The Halogen Occultation Experiment (HALOE) on NASA's Upper Atmosphere Research Satellite...

  16. Effects of some organic materials on bicarbonate extractable phosphate content of soils having different pH

    Directory of Open Access Journals (Sweden)

    Nutullah Özdemir

    2016-10-01

    Full Text Available This study was carried out to determine the effects of rice husk compost (RC, town waste compost (TW and tobacco waste (TB on bicarbonate extractable phosphate content (P in soils having different pH levels under greenhouse conditions. Soil samples used in this study were taken from surfaces (0-20 cm of agricultural fields around Samsun, Northern Anatolia. The experiment was conducted according to split plot design with four doses of organic matterials (0, 2.5, 5.0 and 7.5, %. After a month of mixing organic matterials into soils, lettuce were grown in the medias. According to the results, RC, TW and TB applications into acidic (Tepecik, neutral (Kampüs and alkaline (Çetinkaya soils increased extractable P content. It was observed that effectiveness of organic matterials changed depend on soil reaction, type and dose of organic matterials. All organic wastes were more effective on increment of bicarbonate extractable phosphate content in neutral soil pH when compared the other soil pH levels.

  17. Characterisation of solvent extractable organic constituents in atmospheric particulate matter: an overview

    Directory of Open Access Journals (Sweden)

    Célia A. Alves

    2008-03-01

    Full Text Available In spite of accounting for 10-70% of the atmospheric aerosol mass, particulate-phase organic compounds are not well characterised, and many aspects of aerosol formation and evolution are still unknown. The growing awareness of the impact of particulate aerosols on climate, and the incompletely recognised but serious effects of anthropogenic constituents on air quality and human health, have conducted to several scientific studies. These investigations have provided information about the behaviour of atmospheric particulate matter and the description of the character of its carbonaceous content. The compilation of such results is important as they append to the emergent global-wide dataset of the organic composition of atmospheric aerosols. The contribution of the major emission sources to regional particulate pollution can be diagnosed by using specific molecular markers. This overview is mainly focused on results obtained with gas chromatography coupled with mass spectrometry, since it is the analytical method of choice in elucidating the solvent-extractable organic compounds in atmospheric particulate matter. A synopsis of the selection of organic tracers and the application of geochemical parameters to the analysis of organic constituents as a tool for source apportionment is shown here. Besides the assessment of current knowledge, this paper also presents the identification of further areas of concern.Apesar de constituirem 10-70% da massa do aerosol atmosférico, a caracterização dos compostos orgânicos particulados permanece ainda deficitária e vários aspectos relativos à formação e evolução do aerossol são ainda desconhecidos. A crescente preocupação com o impacto do aerosol particulado no clima e os reconhecidos efeitos dos constituintes antropogênicos na qualidade do ar e na saúde humana têm motivado a realização de numerosos estudos. Estas investigações têm fornecido informações relevantes sobre o comportamento

  18. Capabilities and limitations of dispersive liquid-liquid microextraction with solidification of floating organic drop for the extraction of organic pollutants from water samples.

    Science.gov (United States)

    Vera-Avila, Luz E; Rojo-Portillo, Tania; Covarrubias-Herrera, Rosario; Peña-Alvarez, Araceli

    2013-12-17

    Dispersive liquid-liquid microextraction with solidification of floating organic drop (DLLME-SFO) is one of the most interesting sample preparation techniques developed in recent years. Although several applications have been reported, the potentiality and limitations of this simple and rapid extraction technique have not been made sufficiently explicit. In this work, the extraction efficiency of DLLME-SFO for pollutants from different chemical families was determined. Studied compounds include: 10 polycyclic aromatic hydrocarbons, 5 pesticides (chlorophenoxy herbicides and DDT), 8 phenols and 6 sulfonamides, thus, covering a large range of polarity and hydrophobicity (LogKow 0-7, overall). After optimization of extraction conditions using 1-dodecanol as extractant, the procedure was applied for extraction of each family from 10-mL spiked water samples, only adjusting sample pH as required. Absolute recoveries for pollutants with LogKow 3-7 were >70% and recovery values within this group (18 compounds) were independent of structure or hydrophobicity; the precision of recovery was very acceptable (RSD0.995). Extraction recoveries for pollutants with LogKow 1.46-2.8 were in the range 13-62%, directly depending on individual LogKow values; however, good linearity (r(2)>0.993) and precision (RSD<6.5%) were also demonstrated for these polar solutes, despite recovery level. DLLME-SFO with 1-dodecanol completely failed for extraction of compounds with LogKow≤1 (sulfa drugs), other more polar extraction solvents (ionic liquids) should be explored for highly hydrophilic pollutants. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

    Science.gov (United States)

    Goodman, M.M.; Faraj, B.

    1999-07-06

    Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

  20. Occurrence and concentrations of selected trace elements, halogenated organic compounds, and polycyclic aromatic hydrocarbons in streambed sediments and results of water-toxicity testing in Westside Creeks and the San Antonio River, San Antonio, Texas, 2014

    Science.gov (United States)

    Crow, Cassi L.; Wilson, Jennifer T.; Kunz, James L.

    2016-12-01

    Sediment samples and samples for water-toxicity testing were collected during 2014 from several streams in San Antonio, Texas, known locally as the Westside Creeks (Alazán, Apache, Martínez, and San Pedro Creeks) and from the San Antonio River. Samples were collected during base flow and after periods of stormwater runoff (poststorm conditions) to determine baseline sediment- and water-quality conditions. Streambed-sediment samples were analyzed for selected constituents, including trace elements and organic contaminants such as pesticides, polychlorinated biphenyls (PCBs), brominated flame retardants, and polycyclic aromatic hydrocarbons (PAHs). Potential risks of contaminants in sediment were evaluated by comparing concentrations of contaminants in sediment to two effects-based sediment-quality guidelines: (1) a lower level, called the threshold effect concentration, below which, harmful effects to benthic biota are not expected, and (2) a higher level, the probable effect concentration (PEC), above which harmful effects are expected to occur frequently. Samples for water-toxicity testing were collected from each stream to provide information about fish toxicity in the study area. The trace metal lead was detected at potentially toxic concentrations greater than the PEC in both the base-flow and poststorm samples collected at two sites sampled on San Pedro Creek. The PECs for the pesticides dichlorodiphenyldichloroethane, dichlorodiphenyldichloroethylene, dichlorodiphenyltrichloroethane, and chlordane were exceeded in some of the samples at the same two sites on San Pedro Creek. Brominated flame retardants and polybrominated diphenyl ether (PBDE) 85, 153, and 154 were found in all streambed-sediment samples. Federal Environmental Quality Guidelines established by Environment Canada for PBDE 99 and PBDE 100 were exceeded in all samples in which PBDE 99 was detected and in a majority of the samples in which PBDE 100 was detected; the greatest concentrations

  1. Lipid extractions from docosahexaenoic acid (DHA)-rich and oleaginous Chlorella sp. biomasses by organic-nanoclays.

    Science.gov (United States)

    Lee, Young-Chul; Huh, Yun Suk; Farooq, Wasif; Chung, Jane; Han, Jong-In; Shin, Hyun-Jae; Jeong, Sang Hwa; Lee, Jin-Suk; Oh, You-Kwan; Park, Ji-Yeon

    2013-06-01

    Microalgae biorefinement has attracted in intensive academic and industrial interest worldwide for its potential to replace petrol biofuels as economically and environmentally advantageous alternatives. However, harvesting and lipid extraction remain as critical and difficult issues to be resolved. In the present study, four amino-groups functionalized organic-nano clays were prepared. Specifically, Mg or Al or Ca backboned and covalently linked with 3-aminopropyltriethoxysilane or 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane by sol-gel reaction under ambient conditions, resulted in Mg-APTES clay, Al-APTES clay, Ca-APTES clay, and Mg-N3 clay, respectively. Each organic-nanoclay was utilized for lipid extraction from wet microalgae biomass. As a result, the lipid-extraction efficiency of paste docosahexaenoic acid (DHA)-rich Chlorella sp. with low lipid content was high, while one of paste oleaginous Chlorella sp. with high lipid content was relatively low. Despite the low lipid-extraction efficiencies in all of the wet microalgae biomass, the conversion of the extracted lipids' fatty acids to biodiesel was nearly 100%.

  2. Fabrication of metal-organic frameworks and graphite oxide hybrid composites for solid-phase extraction and preconcentration of luteolin.

    Science.gov (United States)

    Wang, Yang; Wu, Yichun; Ge, Huali; Chen, Huanhuan; Ye, Guiqin; Hu, Xiaoya

    2014-05-01

    A novel solid-phase extraction sorbent, metal-organic frameworks and graphite oxide hybrid composite, was prepared by a solvothermal technique. The morphology and properties of the resultant material were examined by Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscopy. To evaluate the extraction performance of the resultant sorbent, luteolin was chosen as a model analyte. The extraction conditions were optimized. Based on these, a convenient and efficient solid-phase extraction procedure for the determination of luteolin was established and the subsequent quantification step was performed by square wave anodic stripping voltammetry. Under the optimal conditions, the oxidation current increased linearly with increasing the concentration of luteolin in the range of 5.0 × 10(-9)-5.0 × 10(-7)molL(-1) with a correlation coefficient of 0.9983 and a detection limit of 7.9 × 10(-10)molL(-1). The relative standard deviation of seven successive scans was 4.20% for 5.0 × 10(-8)molL(-1) luteolin. This work not only proposes a useful method for sample pretreatment, but also reveals the great potential of metal-organic frameworks based hybrid materials as an excellent sorbent in solid-phase extraction.

  3. Halogen Bonding: An AIM Analysis of the Weak Interactions

    Institute of Scientific and Technical Information of China (English)

    ZOU, Jian-Wei; LU, Yun-Xiang; YU, Qing-Sen; ZHANG, Hua-Xin; JIANG, Yong-Jun

    2006-01-01

    A series of complexes formed between halogen-containing molecules and ammonia have been investigated by means of the atoms in molecules (AIM) approach to gain a deeper insight into halogen bonding. The existence of the halogen bond critical points (XBCP) and the values of the electron density (ρb) and Laplacian of electron density (▽2pb) at the XBCP reveal the closed-shell interactions in these complexes. Integrated atomic properties such as charge, energy, polarization moment, volume of the halogen bond donor atoms, and the corresponding changes (△) upon complexation have been calculated. The present calculations have demonstrated that the halogen bond represents different AIM properties as compared to the well-documented hydrogen bond. Both the electron density and the Laplacian of electron density at the XBCP have been shown to correlate well with the interaction energy, which indicates that the topological parameters at the XBCP can be treated as a good measure of the halogen bond strength.In addition, an excellent linear relationship between the interatomic distance d(X…N) and the logarithm of ρb has been established.

  4. Halogen chemistry reduces tropospheric O3 radiative forcing

    Science.gov (United States)

    Sherwen, Tomás; Evans, Mat J.; Carpenter, Lucy J.; Schmidt, Johan A.; Mickley, Loretta J.

    2017-01-01

    Tropospheric ozone (O3) is a global warming gas, but the lack of a firm observational record since the preindustrial period means that estimates of its radiative forcing (RFTO3) rely on model calculations. Recent observational evidence shows that halogens are pervasive in the troposphere and need to be represented in chemistry-transport models for an accurate simulation of present-day O3. Using the GEOS-Chem model we show that tropospheric halogen chemistry is likely more active in the present day than in the preindustrial. This is due to increased oceanic iodine emissions driven by increased surface O3, higher anthropogenic emissions of bromo-carbons, and an increased flux of bromine from the stratosphere. We calculate preindustrial to present-day increases in the tropospheric O3 burden of 113 Tg without halogens but only 90 Tg with, leading to a reduction in RFTO3 from 0.43 to 0.35 Wm-2. We attribute ˜ 50 % of this reduction to increased bromine flux from the stratosphere, ˜ 35 % to the ocean-atmosphere iodine feedback, and ˜ 15 % to increased tropospheric sources of anthropogenic halogens. This reduction of tropospheric O3 radiative forcing due to halogens (0.087 Wm-2) is greater than that from the radiative forcing of stratospheric O3 (˜ 0.05 Wm-2). Estimates of RFTO3 that fail to consider halogen chemistry are likely overestimates (˜ 25 %).

  5. Persistence, bioaccumulation, and toxicity of halogen-free flame retardants.

    Science.gov (United States)

    Waaijers, Susanne L; Kong, Deguo; Hendriks, Hester S; de Wit, Cynthia A; Cousins, Ian T; Westerink, Remco H S; Leonards, Pim E G; Kraak, Michiel H S; Admiraal, Wim; de Voogt, Pim; Parsons, John R

    2013-01-01

    Polymers are synthetic organic materials having a high carbon and hydrogen content, which make them readily combustible. Polymers have many indoor uses and their flammability makes them a fire hazard. Therefore, flame retardants (FRs) are incorporated into these materials as a safety measure. Brominated flame retardants (BFRs), which accounted for about 21% of the total world market of FRs, have several unintended negative effects on the environment and human health. Hence, there is growing interest in finding appropriate alternative halogen-free flame retardants (HFFRs). Many of these HFFRs are marketed already, although their environ- mental behavior and toxicological properties are often only known to a limited extent, and their potential impact on the environment cannot yet be properly assessed. Therefore, we undertook this review to make an inventory of the available data that exists (up to September 2011) on the physical-chemical properties, pro- duction volumes, persistence, bioaccumulation, and toxicity (PBT) of a selection of HFFRs that are potential replacements for BFRs in polymers. Large data gaps were identified for the physical-chemical and the PBT properties of the reviewed HFFRs. Because these HFFRs are currently on the market, there is an urgent need to fill these data gaps. Enhanced transparency of methodology and data are needed to reevaluate certain test results that appear contradictory, and, if this does not provide new insights, further research should be performed. TPP has been studied quite extensively and it is clearly persistent, bioaccumulative, and toxic. So far, RDP and BDP have demonstrated low to high ecotoxicity and persistence. The compounds ATH and ZB exerted high toxicity to some species and ALPI appeared to be persistent and has low to moderate reported ecotoxicity. DOPO and MPP may be persistent, but this view is based merely on one or two studies, clearly indicating a lack of information. Many degradation studies have been

  6. Acute toxicity impacts of Euphorbia hirta L extract on behavior, organs body weight index and histopathology of organs of the mice and Artemia salina

    Directory of Open Access Journals (Sweden)

    Mohammad Abu Basma Rajeh

    2012-01-01

    Full Text Available Background: The methanol extract of Euphorbia hirta L (Euphorbiaceae, which is used in traditional medicines, was tested for in vivo toxicity. Materials and Methods: In vivo brine shrimp lethality assay and oral acute toxicity study at single high dose of 5000 mg/kg and observation for 14 days in mice were used to study the toxic effect of E. hirta. Results: Brine shrimp lethality assay was used to calculate the median lethal concentration (LC 50 of E. hirta (for leaves, stems, flowers and roots methanolic extracts at concentrations from 100 to 0.07 mg/ml. The LC 50 values of 1.589, 1.420, 0.206 and 0.0827 mg/ml were obtained for stems, leaves, flowers and roots, respectively. Potassium dichromate (the positive control had LC 50 value of 0.00758 mg/ml. The acute oral toxicity study of the leaf extract resulted in one third mortality and mild behavioral changes among the treated mice. No significant statistical differences found between body weight, relative (% and absolute (g organ weights of treated and untreated groups (P> 0.05. Gross and microscopic examination of the vital organ tissues revealed no differences between control and treated mice. All the tissues appeared normal. Conclusions : E. hirta leaves methanol extract has exhibited mild toxic effects in mice.

  7. Pressurized solvent extraction of environmental organic compounds in soils using a supercritical fluid extractor

    Energy Technology Data Exchange (ETDEWEB)

    Li, K.; Landriault, M.; Fingas, M. [Emergencies Science Division, Environmement Canada, Environment Technology Centre, Ontario (Canada); Llompart, M. [Universidad de Santiago de Compostela (Spain). Dept. de Quimica Analitica, Nutricieon y bromatologia, Facultad de Quimica

    1998-11-01

    The applicability of pressurised solvent extraction (PSE) for the quantitative extraction of different of semi-volatiles, including polycyclic aromatic hydrocarbons (PAHs), phenols, polychlorinated biphenyls (PCBs) and total petroleum hydrocarbons have been evaluated. For this study a conventional supercritical fluid extraction (SFE) system, the Suprex SFE/50 was adapted to function as a pressurised solvent extraction system. Solid samples were weighed into the SFE thimble and extracted using conventional extraction solvents instead of superficial carbon dioxide. Parameters such as extraction temperature and effect of modifiers were investigated. Although limited by the 150 deg. C maximum oven temperature, it was found effective extraction could still be carried out in less than 25 min for all the compounds studied. The technique was applied to different real matrices contaminated with hydrocarbons, PAHs and phenols. Validations of the technique were performed using standard reference materials. Recoveries for these matrices were good (> 75 %) and precision was generally less than a 10 % RSD. Extensive comparison of this technique with sonication and with microwave assisted extraction (MAE) were made, and recoveries were found to be comparable to MAE and superior to sonication. (authors) 15 refs.

  8. Head Space Solid Phase Micro-Extraction (HS - SPME of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636

    Directory of Open Access Journals (Sweden)

    Eunice Valduga

    2010-12-01

    Full Text Available The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636 using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME. Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm, temperature (25-60 ºC, extraction time (10-30 minutes, and sample volume (2-3 mL. The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD. The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v. In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm, temperature (23-33 ºC, pH (4.0-8.0, precursor concentration (0.02-0.1%, mannitol (0-6%, and asparagine concentration (0-0.2% was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

  9. Modeling space-charge-limited currents in organic semiconductors: Extracting trap density and mobility

    KAUST Repository

    Dacuña, Javier

    2011-11-28

    We have developed and have applied a mobility edge model that takes drift and diffusion currents to characterize the space-charge-limited current in organic semiconductors into account. The numerical solution of the drift-diffusion equation allows the utilization of asymmetric contacts to describe the built-in potential within the device. The model has been applied to extract information of the distribution of traps from experimental current-voltage measurements of a rubrene single crystal from Krellner showing excellent agreement across several orders of magnitude in the current. Although the two contacts are made of the same metal, an energy offset of 580 meV between them, ascribed to differences in the deposition techniques (lamination vs evaporation) was essential to correctly interpret the shape of the current-voltage characteristics at low voltage. A band mobility of 0.13cm 2V-1s-1 for holes is estimated, which is consistent with transport along the long axis of the orthorhombic unit cell. The total density of traps deeper than 0.1 eV was 2.2×1016cm -3. The sensitivity analysis and error estimation in the obtained parameters show that it is not possible to accurately resolve the shape of the trap distribution for energies deeper than 0.3 eV or shallower than 0.1 eV above the valence-band edge. The total number of traps deeper than 0.3 eV, however, can be estimated. Contact asymmetry and the diffusion component of the current play an important role in the description of the device at low bias and are required to obtain reliable information about the distribution of deep traps. © 2011 American Physical Society.

  10. Ionic liquid-functionalized silica for selective solid-phase extraction of organic acids, amines and aldehydes.

    Science.gov (United States)

    Vidal, Lorena; Parshintsev, Jevgeni; Hartonen, Kari; Canals, Antonio; Riekkola, Marja-Liisa

    2012-02-24

    Three ionic liquid (IL)-functionalized silica materials, imidazolium, N-methylimidazolium and 1-alkyl-3-(propyl-3-sulfonate) imidazolium, were synthesised and applied in solid-phase extraction (SPE) of organic acids, amines and aldehydes, which are important compound families in atmospheric aerosol particles. 1-Alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica was tested as sorbent for SPE for the first time. The analytes were separated and detected by liquid chromatography-mass spectrometry (LC-MS). To confirm the results achieved by LC-MS, the acids were additionally determined by gas chromatography-mass spectrometry (GC-MS). The stability of the IL-functionalized silica materials was tested at low and high pH. The effect of the pH on the extraction was also informative of the retention mechanism of the materials. The results showed anion exchange to be the main interaction, but hydrophobic and π interactions and hydrogen bonding also played a role in the extraction. Extraction efficiencies for organic acids ranged from 87 to 110%, except for cis-pinonic acid (19-29%). Lower extraction efficiencies for amines and aldehydes confirmed that anionic exchange was the predominant interaction. Comparisons made with two commercial SPE materials--silica-based strong anion exchange (SAX) and polymer-based mixed-mode anion exchange and reverse-phase (MAX)--showed the IL-functionalized materials to offer different selectivity and better extraction efficiency than SAX for aromatic compounds. Finally, the new materials were successfully tested in the extraction of an atmospheric aerosol sample.

  11. Investigation of extractable organic compounds in deep-sea hydrothermal vent fluids along the Mid-Atlantic Ridge

    Science.gov (United States)

    McCollom, Thomas M.; Seewald, Jeffrey S.; German, Christopher R.

    2015-05-01

    The possibility that deep-sea hydrothermal vents may contain organic compounds produced by abiotic synthesis or by microbial communities living deep beneath the surface has led to numerous studies of the organic composition of vent fluids. Most of these studies have focused on methane and other light hydrocarbons, while the possible occurrence of more complex organic compounds in the fluids has remained largely unstudied. To address this issue, the presence of higher molecular weight organic compounds in deep-sea hydrothermal fluids was assessed at three sites along the Mid-Atlantic Ridge that span a range of temperatures (51 to >360 °C), fluid compositions, and host-rock lithologies (mafic to ultramafic). Samples were obtained at several sites within the Lucky Strike, Rainbow, and Lost City hydrothermal fields. Three methods were employed to extract organic compounds for analysis, including liquid:liquid extraction, cold trapping on the walls of a coil of titanium tubing, and pumping fluids through cartridges filled with solid phase extraction (SPE) sorbents. The only samples to consistently yield high amounts of extractable organic compounds were the warm (51-91 °C), highly alkaline fluids from Lost City, which contained elevated concentrations of C8, C10, and C12n-alkanoic acids and, in some cases, trithiolane, hexadecanol, squalene, and cholesterol. Collectively, the C8-C12 acids can account for about 15% of the total dissolved organic carbon in the Lost City fluids. The even-carbon-number predominance of the alkanoic acids indicates a biological origin, but it is unclear whether these compounds are derived from microbial activity occurring within the hydrothermal chimney proximal to the site of fluid discharge or are transported from deeper within the system. Hydrothermal fluids from the Lucky Strike and Rainbow fields were characterized by an overall scarcity of extractable dissolved organic compounds. Trace amounts of aromatic hydrocarbons including

  12. Halogenated MOF-5 variants show new configuration, tunable band gaps and enhanced optical response in the visible and near infrared.

    Science.gov (United States)

    Yang, Li-Ming; Fang, Guo-Yong; Ma, Jing; Pushpa, Raghani; Ganz, Eric

    2016-11-30

    Inspired by recent experimental fabrication of mono-halogenated versions of Metal-Organic Framework MOF-5 (i.e., X-MOF-5, X = F to I) and some experimentally known fully halogenated MOF compounds, we systematically studied frameworks incorporating full halogenation of the BDC linkers of the prototypical Iso-Reticular Metal-Organic Framework (IRMOF) series, exemplified by MOF-5. Using quantum chemistry calculations, we find that halogenation leads to a 90° rotation of the aryl group, which is mainly ascribed to overcrowding between halogen atoms and the carboxyl and benzene ring and strong repulsion among in-plane atoms/groups. The 90° configuration decreases the repulsion, and maximizes the stabilization energy, and is therefore more stable than 0° configuration. We find that the band gap can be tuned from 4.1 to 1.5 eV as we go from F, Cl, Br, to I. This extends the optical response of these experimentally accessible materials through the visible and infrared region. We have also considered a broader range of new materials that substitute various metals for Zn. Totally, 70 materials were systematically examined computationally including (M4O)(BDC-Z4)3 (M = Zn, Cd, Be, Mg, Ca, Sr, Ba; Z = H, F, Cl, Br, I). For the full range of materials, we calculate band gaps of 4.2 to 1.0 eV, corresponding to a threshold of absorption of 290-1240 nm. Four selected materials were tested for stability using short 5 ps molecular dynamics simulations up to 600 K. The new materials with the smallest band gaps could potentially be used in near-infrared (NIR) light-emitting devices. Other properties, e.g., bulk moduli, formation energy, chemical bonding, and optical properties, were also investigated. The present results may provide new materials for use as novel photocatalysts, photoactive materials for photovoltaic cells, or functional devices in nanoelectronics and optoelectronics.

  13. Electro-driven extraction of inorganic anions from water samples and water miscible organic solvents and analysis by ion chromatography.

    Science.gov (United States)

    Nojavan, Saeed; Bidarmanesh, Tina; Memarzadeh, Farkhondeh; Chalavi, Soheila

    2014-09-01

    A simple electromembrane extraction (EME) procedure combined with ion chromatography (IC) was developed to quantify inorganic anions in different pure water samples and water miscible organic solvents. The parameters affecting extraction performance, such as supported liquid membrane (SLM) solvent, extraction time, pH of donor and acceptor solutions, and extraction voltage were optimized. The optimized EME conditions were as follows: 1-heptanol was used as the SLM solvent, the extraction time was 10 min, pHs of the acceptor and donor solutions were 10 and 7, respectively, and the extraction voltage was 15 V. The mobile phase used for IC was a combination of 1.8 mM sodium carbonate and 1.7 mM sodium bicarbonate. Under these optimized conditions, all anions had enrichment factors ranging from 67 to 117 with RSDs between 7.3 and 13.5% (n = 5). Good linearity values ranging from 2 to 1200 ng/mL with coefficients of determination (R(2) ) between 0.987 and 0.999 were obtained. The LODs of the EME-IC method ranged from 0.6 to 7.5 ng/mL. The developed method was applied to different samples to evaluate the feasibility of the method for real applications.

  14. The evaluation of solid phase micro-extraction fibre types for the analysis of organic components in unburned propellant powders.

    Science.gov (United States)

    Dalby, Oliver; Birkett, Jason W

    2010-11-12

    This work describes the evaluation of various solid phase micro-extraction (SPME) fibre types for the detection of compounds originating from particles of unburned propellant powders. These compounds may also be found in association with organic gunshot residues (OGSR). Seven SPME fibres were assessed based on their ability to extract the compounds of interest (diphenylamine (DPA), 4-nitrodiphenylamine (4-NDPA), ethyl centralite (EC), nitroglycerin (NG) and dibutyl phthalate (DBP)) from four ammunition types across three calibres (9 mm, 5.56 mm and 7.62 mm). Extracts were analysed by gas chromatography/mass spectrometry (GC/MS). Results indicated that the 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) was the most suitable fibre type for the extraction of these compounds across the ammunition types tested. Optimal extraction time parameters were also assessed with a 35-min period determined to be suitable. A number of previously unreported considerations for extracting propellant powders and potentially OGSR related materials are discussed.

  15. ASE extraction method for simultaneous carbon and nitrogen stable isotope analysis in soft tissues of aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Nathalie [ISM/LPTC, UMR 5255 CNRS, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France); CRH, UMR 212 EME, Institut de Recherche et de Developpement, Av Jean Monnet BP171, 34203 Sete (France); Budzinski, Helene, E-mail: h.budzinski@ism.u-bordeaux1.fr [ISM/LPTC, UMR 5255 CNRS, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France); Le Menach, Karyn; Tapie, Nathalie [ISM/LPTC, UMR 5255 CNRS, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France)

    2009-06-08

    Since lipids are depleted in {sup 13}C relative to proteins and carbohydrates, variations in lipid composition among species and within individuals significantly influence {delta}{sup 13}C and may result in misleading ecological interpretations. Whereas lipid extraction before IRMS analysis constitutes a way of stable isotope result lipid-normalisation, such a procedure was given up because of the un-controlled effects of the methods used (i.e., 'Bligh and Dyer', Soxhlet, etc.) on {delta}{sup 15}N. The aim of this work was to develop a simple, rapid and efficient lipid extraction method allowing for simultaneous C and N stable isotope analysis in the biological soft tissues of aquatic organisms. The goal was to be free from the lipid influence on {delta}{sup 13}C values without interfering with {delta}{sup 15}N values. For that purpose, the modern automated pressurized liquid extraction technique ASE (accelerated solvent extraction) was selected. Eel muscles representative of a broad range of fat contents were extracted via ASE by using different semi-polar solvents (100% dichloromethane and 80% n-hexane/20% acetone) and by operating at different temperature (ambient temperature and 100 deg. C) and pressure (750 and 1900 psi) conditions. The results were discussed in terms of lipid extraction efficiency as well as {delta}{sup 13}C and {delta}{sup 15}N variability.

  16. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    Science.gov (United States)

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method.

  17. Synthesis of Soluble Halogenated Polyphenylenes. Mechanism for the Coupling Halogenated Lithiobenzenes

    Science.gov (United States)

    1993-11-22

    the halogen content in these polymers was lowered using larger amounts of tert- butyllithium. TGA analysis (N2 , 20C/rmin) of I1 showed a 10% weight...iodide for every three aryl rings. DSC analysis (N2 , 20°C/min) for 1 8 showed no transitions on either the first or second heating scans to 230"C. TGA ... analysis (N2. 20C/rmin) showed a 10% weight loss at 3220C and char yields of 46% at 900"C. Visual analysis of the charred material did indicate that

  18. Effects of soil oven-drying on concentrations and speciation of trace metals and dissolved organic matter in soil solution extracts of sandy soils

    NARCIS (Netherlands)

    Koopmans, G.F.; Groenenberg, J.E.

    2011-01-01

    Weak salt extracts can be used to assess the availability of trace metals for leaching and uptake by soil organisms and plants in soil. Before extraction, the International Organization for Standardization recommends to dry soils in an oven at a temperature of 40 °C. Effects of soil oven-drying on

  19. Effects of soil oven-drying on concentrations and speciation of trace metals and dissolved organic matter in soil solution extracts of sandy soils

    NARCIS (Netherlands)

    Koopmans, G.F.; Groenenberg, J.E.

    2011-01-01

    Weak salt extracts can be used to assess the availability of trace metals for leaching and uptake by soil organisms and plants in soil. Before extraction, the International Organization for Standardization recommends to dry soils in an oven at a temperature of 40 °C. Effects of soil oven-drying on d

  20. Composite hollow fiber membranes for organic solvent-based liquid-liquid extraction

    NARCIS (Netherlands)

    He, T.; Bolhuis-Versteeg, Lydia A.M.; Mulder, M.H.V.; Wessling, Matthias

    2004-01-01

    Instability issues of liquid membranes extraction significantly limit its wide application in industry. We report research on the application of a new composite hollow fiber membrane to stabilizing liquid membrane extraction. These type of composite membranes have either a polysulfone (PSf) ultrafil

  1. Insect lipid profile: aqueous versus organic solvent-based extraction methods

    NARCIS (Netherlands)

    Tzompa Sosa, D.A.; Yi, L.; Valenberg, van H.J.F.; Boekel, van M.A.J.S.; Lakemond, C.M.M.

    2014-01-01

    In view of future expected industrial bio-fractionation of insects, we investigated the influence of extraction methods on chemical characteristics of insect lipids. Lipids from Tenebrio molitor, Alphitobius diaperinus, Acheta domesticus and Blaptica dubia, reared in the Netherlands, were extracted

  2. Antifungal properties of organic extracts of eight Cistus L. species against postharvest citrus sour rot.

    Science.gov (United States)

    Karim, H; Boubaker, H; Askarne, L; Talibi, I; Msanda, F; Boudyach, E H; Saadi, B; Ait Ben Aoumar, A

    2016-01-01

    The effectiveness of methanol and chloroform extracts of eight Cistaceae species to control citrus sour rot decay, caused by Geotrichum citri-aurantii, was investigated in both in vitro and in vivo conditions. Methanol extracts of these plant species exhibited more interesting activity against G. citri-aurantii, in both in vitro and in vivo conditions, compared with chloroforme extracts. Under in vitro trials, obtained results showed that methanol extracts of all tested plants revealed a highest significant antifungal activity with inhibition zones that ranged between 12·33 and 16·33 mm in diameter. All tested methanol extracts totally inhibited spore germination when tested at 10 mg ml(-1) . Incidence of sour rot was significantly lowered to 11·11% when fruits were treated with Cistus populifolius and Cistus ladanifer methanol extracts compared with 100% in the control. The disease severity was lowered to 5·19% and 6·04% when fruits were treated with the same methanol extracts respectively. The methanol Cistus extracts had sufficient antifungal activities in vitro and in vivo against G. citri-aurantii to consider its use in the citrus industry after it has been tested under production and natural infection conditions. Such natural products therefore represent a viable alternative approaches for sour rot postharvest management of citrus. © 2015 The Society for Applied Microbiology.

  3. Composite hollow fiber membranes for organic solvent-based liquid-liquid extraction

    NARCIS (Netherlands)

    He, T.; Versteeg, L.A.M.; Mulder, M.H.V.; Wessling, M.

    2004-01-01

    Instability issues of liquid membranes extraction significantly limit its wide application in industry. We report research on the application of a new composite hollow fiber membrane to stabilizing liquid membrane extraction. These type of composite membranes have either a polysulfone (PSf) ultrafil

  4. Comparison of Supercritical Extraction and Organic Solvents Extraction of Pepper Flavour Substances%花椒风味物质超临界萃取与有机溶剂萃取的比较

    Institute of Scientific and Technical Information of China (English)

    张郁松

    2014-01-01

    The supercritical extraction and organic solvent extraction methods for pepper flavor sub-stances are studied in this paper.Comparison of the extraction yield,extraction conditions,extraction cost and sensory quality of flavor substances.The results show that the supercritical extraction meth-od is better than organic solvent extraction method.%研究了花椒风味的有机溶剂和超临界CO2两种提取方法。对比了风味物质的提取率、提取条件、提取成本和感官品质,结果表明:超临界CO2提取花椒风味成分的效果明显优于有机溶剂法。

  5. Evaluation of antiangiogenic and antiproliferative potential of the organic extract of green algae chlorella pyrenoidosa

    Directory of Open Access Journals (Sweden)

    Mahender Kyadari

    2013-01-01

    Full Text Available Objective: algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites expected to have pharmaceutical significance for new drug development. This study was conducted to evaluate the antiangiogenic and antiproliferative activity of Chlorella pyrenoidosa in experimental models of angiogenesis and by MTT assay. Materials and Methods: lyophilized extract of C. pyrenoidosa was extracted using dichloromethane/methanol (2:1, concentrated and vacuum evaporated to obtain the dried extract. The crude extract was evaluated in the vascular endothelial growth factor (VEGF-induced angiogenesis in in ovo chick chorioallantoic membrane assay (CAM at various concentrations (n = 8 using thalidomide and normal saline as positive and untreated control groups, respectively. The crude extract was also subjected to the antiangiogenic activity in the silver nitrate/potassium nitrate cautery model of corneal neovascularization (CN in rats where topical bevacizumab was used as a positive control. The vasculature was photographed and blood vessel density was quantified using Aphelion imaging software. The extract was also evaluated for its anti proliferative activity by microculture tetrazolium test (MTT assay using HeLa cancer cell line (ATCC. Results: VEGF increased the blood vessel density by 220% as compared to normal and thalidomide treatment decreased it to 67.2% in in ovo assay. In the in-vivo CN model, the mean neovascular density in the control group, the C. pyrenoidosa extract and bevacizumab group were found to be 100%, 59.02%, and 32.20%, respectively. The Chlorella pyrenoidosa extract negatively affected the viability of HeLa cells. An IC 50 value of the extract was 570 μg/ml, respectively. Conclusion: a significant antiangiogenic activity was observed against VEGF-induced neovascularization and antiproliferative activity by MTT assay. In this study, it could be attributed that the

  6. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada.

    Science.gov (United States)

    Leiker, Thomas J; Abney, Sonja R; Goodbred, Steven L; Rosen, Michael R

    2009-03-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596 microg kg(-1) wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (<51 microg kg(-1) ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  7. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

    Science.gov (United States)

    Leiker, T.J.; Abney, S.R.; Goodbred, S.L.; Rosen, Michael R.

    2009-01-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596????g kg- 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (< 51????g kg- 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  8. INTERACTION’S EFFECT OF ORGANIC MATERIAL AND AGGREGATION ON EXTRACTION EFFICIENCY OF TPHS FROM PETROLEUM CONTAMINATED SOILS WITH MAE

    Directory of Open Access Journals (Sweden)

    H. Ganjidoust and Gh. Naghizadeh

    2005-10-01

    Full Text Available Microwave-Assisted Extraction (MAE is a type of low-temperature thermal desorption process that its numerous advantages have caused a wide spread use of it. Microwave heating is a potentially attractive technique as it provides volumetric heating process to improve heating efficiencies as compared with conventional techniques. The ability to rapidly heat the sample solvent mixture is inherent to MAE and the main advantage of this technique. Presently MAE has been shown to be one of the best technologies for removing environmental pollutants specially PAHs, phenols and PCBs from soils and sediments. Five different mixtures and types of aggregation (Sand, Top soil, Kaolinite besides three concentrations of crude oil as a contaminant (1000, 5000 and 10000 mg/L were considered. The results indicated that regardless of aggregation, the presence of humus component in soil reduces the efficiency. Minimum and maximum efficiencies were for sandy soil (containing organic components and kaolinite (without any organic content, respectively. According to the results of this research when some amount of humus and organic materials are available in the matrix, it causes the extraction efficiency to perform as a function of just humus materials but not aggregation. Increasing the concentration of crude oil reduced the efficiency with a sharp steep for higher concentration (5000-10000 mg/L and less steeper for lower concentration (1000-5000 mg/L. The concentration of the contaminant, works just as an independent function with extraction time and aggregation factors. The extraction period of 10 min. can be suggested as an optimum extraction time in FMAE for PAHs contaminated soils.

  9. Determination of terpenoid content in pine by organic solvent extraction and fast-GC analysis

    Directory of Open Access Journals (Sweden)

    Anne Elizabeth Harman-Ware

    2016-01-01

    Full Text Available Terpenoids, naturally occurring compounds derived from isoprene units present in pine oleoresin, are a valuable source of chemicals used in solvents, fragrances, flavors and have shown potential use as a biofuel. This paper describes a method to extract and analyze the terpenoids present in loblolly pine saplings and pine lighter wood. Various extraction solvents were tested over different times and temperatures. Samples were analyzed by pyrolysis-molecular beam mass spectrometry before and after extractions to monitor the extraction efficiency. The pyrolysis studies indicated that the optimal extraction method used a 1:1 hexane/acetone solvent system at 22°C for 1 h. Extracts from the hexane/acetone experiments were analyzed using a low thermal mass modular accelerated column heater for fast-GC/FID analysis. The most abundant terpenoids from the pine samples were quantified, using standard curves, and included the monoterpenes, α- and β- pinene, camphene and δ-carene. Sesquiterpenes analyzed included caryophyllene, humulene and α-bisabolene. Diterpenoid resin acids were quantified in derivatized extractions, including pimaric, isopimaric, levopimaric, palustric, dehydroabietic, abietic and neoabietic acids.

  10. Enhanced Nematicidal Activity of Organic and Inorganic Ammonia-Releasing Amendments by Azadirachta indica Extracts.

    Science.gov (United States)

    Oka, Yuji; Tkachi, Nadia; Shuker, Shimshon; Yerumiyahu, Uri

    2007-03-01

    The nematicidal activities of ammonium sulfate, chicken litter and chitin, alone or in combination with neem (Azadirachta indica) extracts were tested against Meloidogyne javanica. Soil application of these amendments or the neem extracts alone did not reduce the root galling index of tomato plants or did so only slightly, but application of the amendments in combination with the neem extracts reduced root galling significantly. Soil analysis indicated that the neem extract inhibited the nitrification of the ammonium released from the amendments and extended the persistence of the ammonium concentrations in the soil. In microplot experiments, tomato plants were grown in pots filled with soils from the treated microplots. The galling indices of tomato plants grown in soil treated with ammonium sulfate or chicken litter in combination with the neem extract or a chemical nitrification inhibitor were far lower than those of plants grown in the control soil or in soil treated with chicken litter, neem extract or nitrification inhibitor alone. However, plants grown in the microplots showed only slight reductions in galling, probably because the soil amendments were inadequately mixed compared to their application in the pot experiments. The extended exposure of nematodes to ammonia as a result of nitrification inhibition by the neem extracts appeared to be the cause of the enhanced nematicidal activity of the ammonia-releasing amendments.

  11. Extraction of garlic with supercritical CO2 and conventional organic solvents

    Directory of Open Access Journals (Sweden)

    J. M. del Valle

    2008-09-01

    Full Text Available Garlic (Allium sativum L. and garlic extracts have therapeutical properties that stem from their sulfur-containing compounds, mainly allicin. The main objective of this work was to compare conventional and "premium" garlic extracts in terms of yield and quality, with the latter being obtained using supercritical carbon dioxide (SC-CO2 as the solvent. Yield ranged between 0.65 and 1.0% and increased with extraction pressure (150-400 bar at a constant temperature of 50°C. Extraction temperature (35-60°C, on the other hand, had little effect at a constant pressure of 300 bar. Based on yield and quality considerations, the best extraction conditions using SC-CO2 were 35-50°C and 300-400 bar. A yield of 5.5% was obtained by conventional extraction using ethanol as the solvent, but ethanol appeared to be less selective for valuable components than SC-CO2. The use of fresh garlic resulted in extracts that more closely resembled commercial products, possibly because of thermal and oxidative degradation of valuable microconstituents during drying.

  12. [Formation of the third phase and spectroscopic research of the loading organic phases in the gold extraction].

    Science.gov (United States)

    Jiang, Jian-zhun; Zhou, Wei-jin; Gao, Hong-cheng; Chen, Jing; Wu, Jin-guang

    2002-06-01

    The formation of the third phase during the gold extraction from cyanide solution by quaternary ammonium, tetradecyldimethylbenzylammonium chloride (TDMBAC) was studied by 198Au tracer method. The microstructure of the organic phases was investigated by FTIR, 31P-NMR. With the increasing of gold concentration, aggregations were formed in the gold-loaded organic phase. With the further increasing of gold concentration, the organic phase turned into two layers. Gold, water, and tri-n-butyl phosphate (TBP) were mainly in the down organic phase. In the down layer, distinct O-H stretching vibration peak was found by FTIR; the frequency of P=O stretching vibration shifted to the low frequency; 31P-NMR chemical shift was markedly shifted to the high frequency field. The radius of aggregation was measured by the dynamic laser scattering (DLS) method.

  13. Evaluation of DNA extraction techniques for detecting Mycobacterium tuberculosis complex organisms in Asian elephant trunk wash samples.

    Science.gov (United States)

    Kay, Meagan K; Linke, Lyndsey; Triantis, Joni; Salman, M D; Larsen, R Scott

    2011-02-01

    Rapid and sensitive diagnostic assays for the detection of tuberculous mycobacteria in elephants are lacking. DNA extraction with PCR analysis is useful for tuberculosis screening in many species but has not been validated on elephant trunk wash samples. We estimated the analytical sensitivity and specificity of three DNA extraction methods to detect Mycobacterium tuberculosis complex organisms in trunk wash specimens. A ZR soil microbe DNA kit (ZR) and a traditional salt and ethanol precipitation (TSEP) approach were evaluated under three different treatment conditions: heat treatment, phenol treatment, and contamination with Mycobacterium avium. A third approach, using a column filtration method, was evaluated for samples contaminated with soil. Trunk wash samples from uninfected elephants were spiked with various concentrations of M. bovis cells and subjected to the described treatment conditions prior to DNA extraction. Extracted DNA was amplified using IS6110-targeted PCR analysis. The ZR and TSEP methods detected as low as 1 to 5 M. bovis cells and 10 M. bovis cells, respectively, per 1.5 ml of trunk wash under all three conditions. Depending on the amount of soil present, the column filtration method detected as low as 5 to 50 M. bovis cells per 1.5 ml of trunk wash. Analytical specificity was assessed by DNA extraction from species of nontuberculous mycobacteria and amplification using the same PCR technique. Only M. bovis DNA was amplified, indicating 100% analytical specificity of this PCR technique. Our results indicate that these DNA extraction techniques offer promise as useful tests for detection of M. tuberculosis complex organisms in elephant trunk wash specimens.

  14. Induction of rat hepatic P4501A1 by organic extracts from airborne particulate matter in Santiago, Chile.

    Science.gov (United States)

    Quiñones, L; Gil, L

    1995-01-01

    1. Organic extracts from particulate matter collected in downtown Santiago, Chile, in 1990 were administered to female Wistar rats. 2. Extracts shifted the maximal absorption wavelength P450 spectra of the reduced-CO complex of hepatic microsomal P450 from 450 to 448 nm, and enhanced the total content of P450. In addition, substantial increases in aryl hydrocarbon hydroxylase, ethoxyresorufin O-deethylase and ethoxycoumarin O-deethylase activities were observed, whereas aminopyrine N-demethylase activity was not affected by treatment. 3. Western blotting using polyclonal antibodies against P4501A isozymes showed the appearance of a distinct and intense P4501A1 band in microsomes from rat pretreated with air particle extracts, and was not observed in microsomes from control rat. On the other hand, the intensity of the P4501A2 isoenzyme was apparently not affected. 4. These findings suggest that the organic extracts from airborne particulate matter modify the composition of rat liver P450 isozymes by inducing those isoforms responsible for the activation of precarcinogenic to carcinogenic agents.

  15. 40 CFR 721.10145 - Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino...

    Science.gov (United States)

    2010-07-01

    ... alcohol, halogenated alkane, substituted epoxide, and amino compound (generic). 721.10145 Section 721... Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino compound... identified generically as modified reaction products of alkyl alcohol, halogenated alkane,...

  16. Lagos lagoon sediment organic extracts and polycyclic aromatic hydrocarbons induce embryotoxic, teratogenic and genotoxic effects in Danio rerio (zebrafish) embryos

    OpenAIRE

    Sogbanmu, Temitope; Nagy, Eszter; Phillips, David Hunter; Arlt, Volker Manfred; Otitoloju, Adebayo; Bury, Nicolas Richard

    2016-01-01

    An expansion of anthropogenic activity around Lagos lagoon, Nigeria has raised concerns over increasing contaminants entering the lagoon’s ecosystem. The embryotoxicity, teratogenicity and genotoxicity of sediment organic extracts from four sampling zones around Lagos lagoon, Ilaje, Iddo, Atlas Cove and Apapa, as well as the dominant polycyclic aromatic hydrocarbons (PAHs) identified in water measured during the wet season (naphthalene, phenanthrene, pyrene, benzo[a]pyrene and a mixture of th...

  17. Evaluation of the effect of an organic extract obtained from Ipomoea alba L. on experimental periodontitis in rats

    OpenAIRE

    Guilherme Emerson Barrella; Ivana Barbosa Suffredini; Fernanda Vieira Ribeiro; Fabiano Ribeiro Cirano; Suzana Peres Pimentel

    2012-01-01

    The aim of this study was to evaluate the effect of an organic extract obtained from Ipomoea alba L. (Convolvulaceae or OE 1493), on experimental periodontal disease in rats. Periodontitis was induced in thirty six Wistar rats: a first mandibular molar was randomly assigned to receive a ligature, whereas the contralateral molar was left unligated. Animals were randomly assigned to two groups and treated topically, three times a day, for 11 days, as follows: Control Group - vehicle-treated (n ...

  18. Organic solvent-free cloud point extraction-like methodology using aggregation of graphene oxide.

    Science.gov (United States)

    Deng, Dongyan; Jiang, Xiaoming; Yang, Lu; Hou, Xiandeng; Zheng, Chengbin

    2014-01-07

    Because of its unique properties and capability of formation of well-dispersed aqueous colloids in aqueous phase, graphene oxide can be used for the efficient preconcentration of heavy metal ions prior to their determination. The complete collection of graphene oxide colloids from water has generally been considered to be insurmountable. Here, graphene oxide aggregation triggered by introducing NaCl was used to develop a novel organic solvent-free cloud point extraction-like method for the determination of trace toxic metals. The graphene oxide sheets were uniformly dispersed in aqueous samples or standard solutions for a fast and efficient adsorption of Pb(II), Cd(II), Bi(III), and Sb(III) owing to its hydrophilic character and the electrostatic repulsion among the graphene oxide sheets, and its aggregation immediately occurred when the electrostatic repulsion was eliminated via adding NaCl to neutralize the excessive negative charges on the surface of graphene oxide sheets. The aggregates of graphene oxide and analytes ions were separated and treated with hydrochloric acid to form a slurry solution. The slurry solution was pumped to mix with KBH4 solution to generate hydrides, which were subsequently separated from the liquid phase and directed to an atomic fluorescence spectrometer or directly introduced to an inductively coupled plasma optical emission spectrometer for detection. On the basis of a 50 mL sample volume, the limits of detection of 0.01, 0.002, 0.01, and 0.006 ng mL(-1) were obtained for Pb, Cd, Bi, and Sb, respectively, when using atomic fluorescence spectrometry, providing 35-, 8-, 36-, and 37-fold improvements over the conventional method. Detection limits of 0.6, 0.15, 0.1, and 1.0 ng mL(-1) were obtained with the use of slurry sampling inductively coupled plasma optical emission spectrometry. The method was applied for analysis of two Certified Reference Materials and three water samples for these elements.

  19. The solvent-extractable organic compounds in the Indonesia biomass burning aerosols - characterization studies

    Science.gov (United States)

    Fang, M.; Zheng, M.; Wang, F.; To, K. L.; Jaafar, A. B.; Tong, S. L.

    The large-scale air pollution episode due to the out-of-control biomass burning for agricultural purposes in Indonesia started in June 1997, has become a severe environmental problem for itself and the neighboring countries. The fire lasted for almost five months. Its impact on the health and ecology in the affected areas is expected to be substantial, costly and possibly long lasting. Air pollution Index as high as 839 has been reported in Malaysia. API is calculated based on the five pollutants: NO 2, SO 2, O 3, CO, and respirable suspended particulates (PM10). It ranges in value from 0 to 500. An index above 101 is considered to be unhealthy and a value over 201 is very unhealthy (Abidin and Shin, 1996). The solvent-extractable organic compounds from four total suspended particulate (TSP) high-volume samples collected in Kuala Lumpur, Malaysia (Stations Pudu and SIRIM) were subjected to characterization - the abundance was determined and biomarkers were identified. Two of the samples were from early September when the fire was less intense, while the other two were from late September when Kuala Lumpur experienced very heavy smoke coverage which could be easily observed from NOAA/AVHRR satellite images. The samples contained mainly aliphatic hydrocarbons such as n-alkanes and triterpanes, alkanoic acids, alkanols, and polycyclic aromatic hydrocarbons. The difference between the early and late September samples was very significant. The total yield increased from 0.6 to 24.3 μg m -3 at Pudu and 1.9 to 20.1 μg m -3 at SIRIM, with increases in concentration in every class. The higher input of vascular plant wax components in the late September samples, when the fire was more intense, was characterized by the distribution patterns of the homologous series n-alkanes, n-alkanoic acids, and n-alkanols, e.g., lower U : R, higher >C 22/C 20/Abas et al., 1995), the present study also showed an absence of conifer tracers in the smoke aerosols indicating tropical wood

  20. Halogen bonded two-dimensional supramolecul arassemblies studied by high resolution scanning tunneling microscopy

    Institute of Scientific and Technical Information of China (English)

    YANG XunYu; WANG Fang; CHEN QiuXia; WANG LiYan; WANG ZhiQiang

    2007-01-01

    We described the formation of self-organized two-dimensional (2D) assemblies of N-(2,3,5,6-tetrafluoro- 4-iodophenyl)hexadecylamine and 1-dodecyl-imidazole at the liquid/HOPG interface. The two-dimen- sional assemblies showed a fishbone-like pattern structure as revealed by high-resolution scanning tunneling microscopy. Although different interactions can drive the formation of 2D assemblies,as far as we know,this is the first report on halogen bond-driven 2D assemblies.

  1. A theoretical model on the formation mechanism and kinetics of highly toxic air pollutants from halogenated formaldehydes reacted with halogen atoms

    Science.gov (United States)

    Ji, Y. M.; Wang, H. H.; Gao, Y. P.; Li, G. Y.; An, T. C.

    2013-11-01

    The atmospheric reactions of halogenated formaldehydes with halogen atoms were investigated by high-accuracy molecular orbital calculation. Our studies showed that compared to X-addition pathway, the H-abstraction pathway was demonstrated to be more preferred to form halogenated formyl radicals and hydrogen halides (HX). In specific areas with abundant halogen atoms, such as the marine boundary layer (MBL), halogenated formyl radical was reacted easily with halogen atoms and finally transformed into HX and CO2 in the presence of water; otherwise, this radical was degraded to CO2, halogen gas, and halogenated oxide in the presence of O2 and halogen atoms. By using the canonical variational transition state theory, the kinetics calculations were performed within a wide atmospheric temperature range of 200-368 K, and theoretical values agreed well with the available experimental data. Under atmospheric conditions, rate constants decreased as altitude increased, and especially the rate constants of halogen atoms reacted with FCHO quickly reduced. The kinetic results showed that although the reactions of halogenated formaldehydes with F atoms occurred more easily than did those with Cl and Br atoms, the two latter reactions were still important atmospheric degradation process, especially in the MBL. The modified Arrhenius equations of rate constants within the atmospheric temperature range were fitted, which helped to understand the established atmospheric model and estimated the contribution of title reactions to atmospheric chemistry pollution.

  2. Surgical extraction of human dorsal root ganglia from organ donors and preparation of primary sensory neuron cultures.

    Science.gov (United States)

    Valtcheva, Manouela V; Copits, Bryan A; Davidson, Steve; Sheahan, Tayler D; Pullen, Melanie Y; McCall, Jordan G; Dikranian, Krikor; Gereau, Robert W

    2016-10-01

    Primary cultures of rodent sensory neurons are widely used to investigate the cellular and molecular mechanisms involved in pain, itch, nerve injury and regeneration. However, translation of these preclinical findings may be greatly improved by direct validation in human tissues. We have developed an approach to extract and culture human sensory neurons in collaboration with a local organ procurement organization (OPO). Here we describe the surgical procedure for extraction of human dorsal root ganglia (hDRG) and the necessary modifications to existing culture techniques to prepare viable adult human sensory neurons for functional studies. Dissociated sensory neurons can be maintained in culture for >10 d, and they are amenable to electrophysiological recording, calcium imaging and viral gene transfer. The entire process of extraction and culturing can be completed in <7 h, and it can be performed by trained graduate students. This approach can be applied at any institution with access to organ donors consenting to tissue donation for research, and is an invaluable resource for improving translational research.

  3. Remediation approach for organic compounds and arsenic co-contaminated soil using pressurized hot water extraction process.

    Science.gov (United States)

    Islam, Mohammad Nazrul; Jo, Young-Tae; Jeong, Yeon-Jae; Park, Jeong-Hun

    2017-09-15

    Successful remediation of soil with co-existing organics contaminants and arsenic (As) is a challenge as the chemical and remediation technologies are different for each group of pollutants. In this study, the treatment effectiveness of pressurized hot water (PHW) extraction process was investigated for remediation of soil co-contaminated with phenol, crude oil, polycyclic aromatic hydrocarbons (PAHs) and As. An elimination percentage of about 99% was achieved for phenol, and in the range of 63-100% was observed for the PAHs at 260 °C for 90 min operation. The performance of PHW extraction in the removal of total petroleum hydrocarbons was found to be 86%. Of the 87 mg/kg of As in untreated soil, 67% of which was eliminated after treatment. The removal of organic contaminants was mainly via desorption, dissolution and degradation in subcritical water, while As was eliminated probably by oxidation and dissolution of arsenic-bearing minerals. According to the experimental results, PHW extraction process can be suggested as an alternative cleaning technology, instead of using any organic solvents for remediation of such co-contaminated soil.

  4. EFFECT OF SUPPLEMENTED DIETS WITH GARLIC ORGANIC EXTRACT AND STREPTOMYCIN SULPHATE ON INTESTINAL MICROFLORA AND NUTRIENTS DIGESTIBILITY IN BROILERS

    Directory of Open Access Journals (Sweden)

    F.E. DIEUMOU

    2011-05-01

    Full Text Available This experiment was carried out to study the effects of garlic organic extract and streptomycin sulphate on intestinal microflora and nutrients digestibility in broilers. Forty eight Hubbard line one day-old chicks with equal numbers of males and females were randomly allocated to eight treatment combinations to conduct a 4 x 2 factorial experiment in a completely randomised design. The diets were supplemented with: no supplement (control, garlic organic extract at 40 ppm/kg (GOE 40 ppm, garlic organic extract at 60 ppm/kg (GOE 60 ppm and streptomycin sulphate at 30 ppm/kg (SS 30 ppm administered by oral gavage from day 13 to day 47 of experiment. There were two birds (males or females per experimental unit, replicated three times in twenty four deep litter pens. The colony forming units of Escherichia coli were significantly reduced (P0.05 in nutrients absorption between male and female broilers. Treatment and sex interaction significantly (P<0.05 affected all the parameters studied indicating a synergistic effect of the two factors on nutrients absorption. It could be concluded that GOE even at 40 ppm/kg controlled pathogens and improved nutrients digestibility in birds.

  5. Soft lithography microlens fabrication and array for enhanced light extraction from organic light emitting diodes (OLEDs)

    Science.gov (United States)

    Leung, Wai Y.; Park, Joong-Mok; Gan, Zhengqing; Constant, Kristen P.; Shinar, Joseph; Shinar, Ruth; ho, Kai-Ming

    2014-06-03

    Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.

  6. Bioactivity of marine organisms: Part 7- Effect of seaweed extract on central nervous system

    Digital Repository Service at National Institute of Oceanography (India)

    Kamat, S.Y.; Wahidullah, S.; DeSouza, L.; Naik, C.G.; Ambiye, V.; Bhakuni, D.S.; Jain, S.; Goel, A.K.; Srimal, R.C.

    Alcohol extracts of marine algae (Rhodophyceae, Phaeophyceae and Chlorophyceae) was screened for their effect on central nervous system. Of 69 species investigated 8 appeared biologically active, 6 being CNS stimulant, sites and dates of collection...

  7. Toxicity to chicken embryos of organic extracts from airborne particulates separated into five sizes

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, H.

    1988-07-01

    The chicken embryo assay has been used for research on the toxicity of complex extracts derived from different environmental sources, as well as of individual compounds. However, only a few studies have been made on the toxicological effects of extracts derived from airborne particulate matter in chicken embryo. These studies showed that the toxic effect was due to the polycyclic aromatic hydrocarbons (PAHs) in the particles, although their structure and quantity were the factors determining the extent of the toxicity. Airborne particulate matter is composed of particles of different sizes, which can be separated into five classes according to their size by an Andersen high-volume sampler. Each class contained many kinds of compounds such as PAHs. In this study, airborne particulate matter was extracted according to particle size, the extracts analyzed for PAHs, and tested for embryotoxicity.

  8. Bioactivity of marine organisms. 6. Antiviral evaluation of marine algal extracts from the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Kamat, S.Y.; Wahidullah, S.; DeSouza, L.; Naik, C.G.; Ambiye, V.; Bhakuni, D.S.; Goel, A.K.; Garg, H.S.; Srimal, R.C.

    Ethanolic extracts of Indian marine algae belonging to the Rhodophyceae, Phaeophyceae and Chlorophyceae were tested for anti-semiliki Forest (SFV), Ranikhet Disease (RDV) and Vaccinia (VV) viruses. In the primary screening of 31 seaweeds, 17...

  9. Needle-type extraction device for the purge and trap analysis of 23 volatile organic compounds in tap water.

    Science.gov (United States)

    Ueta, Ikuo; Razak, Nurhafizza Abd; Mizuguchi, Ayako; Kawakubo, Susumu; Saito, Yoshihiro; Jinno, Kiyokatsu

    2013-11-22

    We developed a rapid determination technique for trace volatile organic compounds (VOCs) in tap water by introducing a novel needle-type extraction device coupled to a purge-and-trap method. To extract a wide range of VOCs, a new extraction needle containing particles of divinylbenzene and activated carbon was developed in this study. During the active sampling of the headspace gas in a glass vial by the extraction needle, pure N2 gas was used for purging the aqueous sample. After the optimization of several experimental parameters, such as the addition of the salt and conditions of dry purging and desorption, the extraction performance of the device and method was evaluated for 23 VOCs that are typically found in tap water samples. The quantification limits of the method were 0.6 μg/L for 1,1-dichloroethylene and less than 0.5 μg/L for other VOCs, with good repeatability being confirmed for all the target compounds. Taking advantage of the excellent recovery of VOCs, the determination of VOCs in real tap water samples was carried out successfully. Because the developed method does not require sample heating and/or cryogenic focusing, simple and rapid analyses can be performed along with satisfactory sensitivity for typical tap water samples.

  10. Characterization of lecithin isolated from anchovy (Engraulis japonica) residues deoiled by supercritical carbon dioxide and organic solvent extraction.

    Science.gov (United States)

    Lee, Seung-Mi; Asaduzzaman, A K M; Chun, Byung-Soo

    2012-07-01

    Lecithin was isolated and characterized from anchovy (Engraulis japonica) deoiled residues using supercritical carbon dioxide (SC-CO(2)) at a semibatch flow extraction process and an organic solvent (hexane) extraction. SC-CO(2) extraction was carried out to extract oil from anchovy at different temperatures (35 to 45 °C) and pressures (15 to 25 MPa). Extraction yield of oil was influenced by physical properties of SC-CO(2) with temperature and pressure changes. The major phospholipids of anchovy lecithin were quantitatively analyzed by high-performance liquid chromatography. Phosphatidylcholine (PC) (68%± 1.00%) and phosphatidylethanolamine (PE) (29%± 0.50%) were the main phospholipids. Thin layer chromatography was performed to purify the individual phospholipids. The fatty acid compositions of lecithin, PC, and PE were analyzed by gas chromatography. A significant amount of eicosapentaenoic acid and docosahexaenoic acid were present in both phospholipids of PC and PE. Emulsions of lecithin in water were prepared through the use of a homogenizer. Oxidative stability of anchovy lecithin was high in spite of its high concentration of long-chain polyunsaturated fatty acids. Lecithin can be totally metabolized by humans, so is well tolerated by humans and nontoxic when ingested. Lecithin from anchovy contain higher amounts of ω-3 fatty acids especially EPA and DHA, it may have positive outcome to use in food and pharmaceutical industries. © 2012 Institute of Food Technologists®

  11. Ionic liquids screening for desulfurization of natural gasoline by liquid-liquid extraction.

    Science.gov (United States)

    Likhanova, Natalya V; Guzmán-Lucero, Diego; Flores, Eugenio A; García, Paloma; Domínguez-Aguilar, Marco A; Palomeque, Jorge; Martínez-Palou, Rafael

    2010-11-01

    Seventy five ionic liquids (ILs) were tested as a sequestering agent of sulfured compounds in natural gasoline (NG). Desulphurization of NG was performed by means of liquid-liquid extraction method at room temperature and atmospheric pressure. Experimental ILs containing imidazolium, pyridinium, and ammonium cations along with organic and inorganic anions were synthesized conventionally and under microwave and sonochemical conditions. The effect of the molecular structure of ILs on the desulfurization efficiency of NG with high sulfur content was evaluated. Analysis indicated that the anion type played a more important role than the cation on the desulphurization process. ILs based on halogen-ferrates and halogen-aluminates exhibited the highest efficiency in sulfur removal, and their efficiency is further improved when there is an excess of metallic salt in a ratio of at least 1:1.3 during the synthesis of the corresponding IL. An explanation for the ability of metallic ILs to remove sulfur-containing compounds from natural gasoline based on the ratio of the ionic charge to the atomic radius is proposed. Furthermore, a method to recover and reuse water-sensitive to halogenated precursors is described.

  12. Investigating Planetary Volatile Accretion Mechanisms Using the Halogens

    Science.gov (United States)

    Ballentine, C. J.; Clay, P. L.; Burgess, R.; Busemann, H.; Ruzié, L.; Joachim, B.; Day, J. M.

    2014-12-01

    Depletion of the volatile elements in the Earth relative to the CI chondrites is roughly correlated with volatility, or decreasing condensation temperature. For the heavy halogen group elements (Cl, Br and I), volatility alone does not account for their apparent depletion, which early data has suggested is far greater than predicted [1-2]. Such depletion has been used to argue for the preferential loss of halogens by, amongst other processes, impact-driven erosive loss from Earth's surface [2]. Little consensus exists as to why the halogens should exhibit such preferential behavior during accretionary processes. Early efforts to constrain halogen abundance and understand their behavior in both Earth and planetary materials [3-6] have been hampered by their typically low abundance (ppb level) in most geologic materials. We present the results of halogen analysis of 23 chondrite samples, selected to represent diverse groups and petrologic type. Halogen abundances were measured by neutron irradiation noble gas mass spectrometry (NI-NGMS). Significant concentration heterogeneity is observed within some samples. However, a single Br/Cl and I/Cl ratio of 1.9 ± 0.2 (x 10-3) and 335 ± 10 (x 10-6) can be defined for carbonaceous chondrites with a good correlation between Br and Cl (R2 = 0.97) and between I and Cl (R2 = 0.84). Ratios of I/Cl overlap with terrestrial estimates of Bulk Silicate Earth and Mid Ocean Ridge Basalts. Similarly, good correlations are derived for enstatite (E) chondrites and a sulfide- and halogen- rich subset of E-chondrites. Chlorine abundances of CI (Orgueil) in this study are lower by factor of ~ 3 than the value of ~ 700 ppm Cl (compilation in [1]). Our results are similar to early discarded low values for Ivuna and Orgueil from [5,6] and agree more closely with values for CM chondrites. Halogens may not be as depleted in Earth as previously suggested, or a high degree of heterogeneity in the abundance of these volatile elements in

  13. The mechanism of halogen liberation in the polar troposphere

    Directory of Open Access Journals (Sweden)

    E. Lehrer

    2004-06-01

    Full Text Available Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely understood. There are several indications that the halogen mobilisation from the sea ice surface of the polar oceans may be the most important source for the necessary halogens. Here we present a 1-D model study aimed at determining the primary source of reactive halogens. The model includes gas phase and heterogeneous bromine and chlorine chemistry as well as vertical transport between the surface and the top of the boundary layer. The autocatalytic Br release by photochemical processes (bromine explosion and subsequent rapid bromine catalysed ozone depletion is well reproduced in the model and the major source of reactive bromine appears to be the sea ice surface. The sea salt aerosol alone is not sufficient to yield the high levels of reactive bromine in the gas phase necessary for fast ozone depletion. However, the aerosol efficiently 'recycles' less reactive bromine species (e.g. HBr and feeds them back into the ozone destruction cycle. Isolation of the boundary layer air from the free troposphere by a strong temperature inversion was found to be critical for boundary layer ozone depletion to happen. The combination of strong surface inversions and presence of sunlight occurs only during polar spring.

  14. Breaching the parts per quadrillion wall in analysis of semivolatile organics

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, C.P.S.; Bouis, P.A. [J.T. Baker Inc., Phillipsburg, NJ (United States)

    1995-12-01

    Analyte enrichments in US Environmental Protection Agency (EPA) methods for environmental pollutants are generally performed using sample preparation techniques such as liquid-liquid extraction, liquid-solid extraction and purge & trap dynamic headspace concentration. The recent development of Solid Phase Microextraction (SPME) has provided another alternative which efficiently extracts organic analytes present in air or aqueous samples. We have successfully developed a unique sample preparation method which combines the power/advantages of Solid Phase Microextraction and standard EPA methodology. Subsequent analysis results in successful detection of ultratrace organic compounds with excellent sensitivity. EPA 525, 625, 8270 semivolatile organic compound have been successfully determined using Gas Chromatography/ Mass Spectrometry (GC/MC) at sub-parts per billion (ppb) levels. EPA 608, 8080 halogenated pesticides have also been readily detected with Electron Capture Detector (ECD) at parts per quadrillion (ppq) levels.

  15. Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

    Science.gov (United States)

    Lim, Seung Joo; Fox, Peter

    2014-02-01

    The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics.

  16. Trypanocidal activity of organic extracts from the Brazilian and Spanish marine sponges

    Directory of Open Access Journals (Sweden)

    Jéssica Carreira de Paula

    2015-12-01

    Full Text Available Abstract Chagas' disease is a parasitic infection caused by protozoan Trypanosoma cruzi that affect millions of people worldwide. The available drugs for treatment of this infection cause serious side effects and have variable efficacy, especially in the chronic phase of the disease. In this context, natural compounds have shown great potential for the discovery of new chemotherapies for the treatment of this infection and various other diseases. In present study, we evaluated the in vitro antiprotozoal activity of five species of Brazilian and Spanish marine sponges (Condrosia reniformes, Tethya rubra, Tethya ignis, Mycale angulosa and Dysidea avara against T. cruzi. By GC–MS data, we observed that in these extracts were present the major classes of the following compounds: hydrocarbons, terpenes, steroids and alcohols. The extracts showed activity against the three forms of this parasite and did not induce toxicity in mammalian cells. Better activities were observed with the extracts of marine sponges, C. reniformes (EC50 = 0.6 μg/ml, D. avara (EC50 = 1.1 μg/ml and M. angulosa (EC50 = 3.8 μg/ml, against trypomastigote forms. In intracellular amastigote forms, the extract of T. ignis showed IC50 of 7.2 μg/ml and SI of 24.65. On this basis, our results indicate that these extracts can be promising chemotherapeutic agents against T. cruzi.

  17. EXTRACTION OF SEDIMENT-BOUND CHLORINATED ORGANIC COMPOUNDS: IMPLICATIONS ON FATE AND HAZARD ASSESSMENT. (R825513C007)

    Science.gov (United States)

    Five methods were used for the extraction of hexachlorobutadiene and chlorobenzenes from a contaminated estuarine sediment. The following extraction methods were used: Soxhlet extraction, sonication and solvent extraction, sequential solvent extraction, saponification and solv...

  18. Antimicrobial Activity and Phytochemical Analysis of Organic Extracts from Cleome spinosa Jaqc.

    Science.gov (United States)

    da Silva, Ana P Sant'Anna; Nascimento da Silva, Luís C; Martins da Fonseca, Caíque S; de Araújo, Janete M; Correia, Maria T Dos Santos; Cavalcanti, Marilene da Silva; Lima, Vera L de Menezes

    2016-01-01

    Due to the use of Cleome spinosa Jacq. (Cleomaceae) in traditional medicine against inflammatory and infectious processes, this study evaluated the in vitro antimicrobial potential and phytochemical composition of extracts from its roots and leaves. From leaves (L) and roots (R) of C. spinosa different extracts were obtained (cyclohexane: ChL and ChR; chloroform: CL and CR; ethyl acetate: EAL and EAR, methanol: ML and MR). The antimicrobial activity was evaluated by the broth microdilution method to obtain the minimum inhibitory (MIC) and microbicidal (MMC) concentrations against 17 species, including bacteria and yeasts. Additionally, antimicrobial and combinatory effects with oxacillin were assessed against eight clinical isolates of Staphylococcus aureus. All C. spinosa extracts showed a broad spectrum of antimicrobial activity, as they have inhibited all tested bacteria and yeasts. This activity seems to be related to the phytochemicals (flavonoid, terpenoids and saponins) detected into the extracts of C. spinosa. ChL and CL extracts were the most actives, with MIC less than 1 mg/mL against S. aureus, Bacillus subtilis, and Micrococcus luteus. It is important to note that these concentrations are much lower than their 50% hemolysis concentration (HC50) values. Strong correlations were found between the average MIC against S. aureus and their phenolic (r = -0.89) and flavonoid content (r = -0.87), reinforcing the possible role of these metabolite classes on the antimicrobial activity of C. spinosa derived extracts. Moreover, CL and CR showed the best inhibitory activity against S. aureus clinical isolates, they also showed synergistic action with oxacillin against all these strains (at least at one combined proportion). These results encourage the identification of active substances which could be used as lead(s) molecules in the development of new antimicrobial drugs.

  19. Antimicrobial Activity and Phytochemical Analysis of Organic Extracts from Cleome spinosa Jaqc.

    Science.gov (United States)

    da Silva, Ana P. Sant'Anna; Nascimento da Silva, Luís C.; Martins da Fonseca, Caíque S.; de Araújo, Janete M.; Correia, Maria T. dos Santos; Cavalcanti, Marilene da Silva; Lima, Vera L. de Menezes

    2016-01-01

    Due to the use of Cleome spinosa Jacq. (Cleomaceae) in traditional medicine against inflammatory and infectious processes, this study evaluated the in vitro antimicrobial potential and phytochemical composition of extracts from its roots and leaves. From leaves (L) and roots (R) of C. spinosa different extracts were obtained (cyclohexane: ChL and ChR; chloroform: CL and CR; ethyl acetate: EAL and EAR, methanol: ML and MR). The antimicrobial activity was evaluated by the broth microdilution method to obtain the minimum inhibitory (MIC) and microbicidal (MMC) concentrations against 17 species, including bacteria and yeasts. Additionally, antimicrobial and combinatory effects with oxacillin were assessed against eight clinical isolates of Staphylococcus aureus. All C. spinosa extracts showed a broad spectrum of antimicrobial activity, as they have inhibited all tested bacteria and yeasts. This activity seems to be related to the phytochemicals (flavonoid, terpenoids and saponins) detected into the extracts of C. spinosa. ChL and CL extracts were the most actives, with MIC less than 1 mg/mL against S. aureus, Bacillus subtilis, and Micrococcus luteus. It is important to note that these concentrations are much lower than their 50% hemolysis concentration (HC50) values. Strong correlations were found between the average MIC against S. aureus and their phenolic (r = −0.89) and flavonoid content (r = −0.87), reinforcing the possible role of these metabolite classes on the antimicrobial activity of C. spinosa derived extracts. Moreover, CL and CR showed the best inhibitory activity against S. aureus clinical isolates, they also showed synergistic action with oxacillin against all these strains (at least at one combined proportion). These results encourage the identification of active substances which could be used as lead(s) molecules in the development of new antimicrobial drugs. PMID:27446005

  20. GC-MS Study of Mono- and Bishaloethylphosphonates Related to Schedule 2.B.04 of the Chemical Weapons Convention: The Discovery of a New Intramolecular Halogen Transfer

    Science.gov (United States)

    Picazas-Márquez, Nerea; Sierra, María; Nova, Clara; Moreno, Juan Manuel; Aboitiz, Nuria; de Rivas, Gema; Sierra, Miguel A.; Martínez-Álvarez, Roberto; Gómez-Caballero, Esther

    2016-09-01

    A new class of compounds, mono- and bis-haloethylphosphonates (HAPs and bisHAPs, respectively), listed in Schedule 2.B.04 of the Chemical Weapons Convention (CWC), has been synthesized and studied by GC-MS with two aims. First, to improve the identification of this type of chemicals by the Organization for the Prohibition of Chemical Weapons, (OPCW). Second, to study the synergistic effect of halogen and silicon atoms in molecules undergoing mass spectrometry. Fragmentation patterns of trimethylsilyl derivatives of HAPs were found to depend on the nature of the halogen atom; this was in agreement with DFT-calculations. The data suggest that a novel intramolecular halogen transfer takes place during the fragmentation process.

  1. Concomitant Use of Sea Cucumber Organic Extract and Radiotherapy on Proliferation and Apoptosis of Cervical (HeLa Cell Line

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    Javad Baharara

    2016-04-01

    Full Text Available Background Cervical carcinoma is gynecologic malignancy with conventional treatment modality but drug resistance interferes with current therapeutic methods. Therefore, identification of novel new modality with low toxicity has uniquely favorable strategy. Objectives The aim of this study is evaluation of concomitant use of sea cucumber organic extract and radiotherapy on ovarian cancer. Materials and Methods In this in vitro experimental study, HeLa cancer cells were cultured and suspended in RPMI (Roswell Park Memorial Institute 1640 medium supplemented with 10 % FBS (Fetal Bovine Serum, 1 % antibiotic. Cells were treated with extract at different concentrations (0 to 100 μg/mL for 24 hours. After determination of suitable concentration, the cells were exposed to 2 Gray gamma radiation in presence of extract for 192 seconds and 66 hours were kept in incubator till anti-proliferative assay were evaluated. To assess apoptosis, flow cytometry with PI (Propodium Iodide and acridine orange staining were performed. Results Morphological analysis and results from cytotoxicity assay exhibited that 50 µg/mL of sea cucumber extract alone is considered IC50 and combination of gamma radiation became more valuable in growth inhibition. Also, flow cytometry histogram of treated cells indicated sub-G1 peak demonstrating disturbance in membrane integrity and apoptosis cell death. Fluorescence images have been confirmed apoptosis cell death in treatment groups. Conclusions These data indicate that sea cucumber extract as novel resource of aquatic natural products significantly can inhibit cervical cancer cell growth and synergistic effect of natural extract along with radiation therapy was more effective in anti-cervical cancer therapy.

  2. Oceanic contributions from tropical upwelling systems to atmospheric halogens

    Science.gov (United States)

    Ziska, Franziska; Hepach, Helmke; Stemmler, Irene; Quack, Birgit; Atlas, Elliot; Fuhlbrügge, Steffen; Bracher, Astrid; Tegtmeier, Susann; Krüger, Kirstin

    2014-05-01

    Short lived halogenated substances (halocarbons) from the oceans contribute to atmospheric halogens, where they are involved in ozone depletion and aerosol formation. Oceanic regions that are characterized by high biological activity are often associated with increased halocarbon abundance of e.g. bromoform (CHBr3) and dibromomethane (CH2Br2), representing the main contributors to atmospheric organic bromine. Apart from biological production, photochemical pathways play an important role in the formation of methyl iodide (CH3I), the most abundant organoiodine in the marine atmosphere. Recently, the contribution of biogenic diiodomethane (CH2I2) and chloroiodomethane (CH2ClI) to atmospheric organic iodine has been estimated to be similarly significant as CH3I. In the tropics, rapid uplift of surface air can transport these short-lived compounds into the upper troposphere and into the stratosphere. Oceanic upwelling systems off Mauritania, Peru and in the equatorial Atlantic might therefore potentially contribute large amounts of halocarbons to the stratosphere. Concentrations and emissions of iodo- and bromocarbons from several SOPRAN campaigns in different tropical upwelling systems, the Mauritanian and the equatorial upwelling in the Atlantic, as well as the Peruvian upwelling in the Pacific, will be presented. Processes contributing to halocarbon occurrence in the water column, as well as biological and physical factors influencing their emission into the atmosphere are investigated (Fuhlbrügge, et al. 2013; Hepach et al., 2013). We will present the relative contribution of the upwelling systems to global air-sea fluxes from different modelling studies. The data based bottom-up emissions from Ziska et al. (2013) will be compared to model simulated halocarbons. The model is a global three-dimensional ocean general circulation model with an ecosystem model and halocarbon module embedded (MPIOM/HAMOCC). It resolves CH3I and CHBr3 production, degradation, and

  3. Phytochemical composition and antimicrobial activities of the essential oils and organic extracts from pelargonium graveolens growing in Tunisia

    Directory of Open Access Journals (Sweden)

    Hsouna Anis

    2012-12-01

    Full Text Available Abstract Background Pelargonium graveolens (P. graveolens L. is an aromatic and medicinal plant belonging to the geraniacea family. Results The chemical compositions of the essential oil as well as the in vitro antimicrobial activities were investigated. The GC-MS analysis of the essential oil revealed 42 compounds. Linallol L, Citronellol, Geraniol, 6-Octen-1-ol, 3,7-dimethyl, formate and Selinene were identified as the major components. The tested oil and organic extracts exhibited a promising antimicrobial effect against a panel of microorganisms with diameter inhibition zones ranging from 12 to 34 mm and MICs values from 0.039 to10 mg/ml. The investigation of the phenolic content showed that EtOAc, MeOH and water extracts had the highest phenolic contents. Conclusion Overall, results presented here suggest that the essential oil and organic extracts of P. graveolens possesses antimicrobial and properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.

  4. Effects of crop rotation and management system on water-extractable organic matter concentration, structure, and bioavailability in a chernozemic agricultural soil.

    Science.gov (United States)

    Xu, Na; Wilson, Henry F; Saiers, James E; Entz, Martin

    2013-01-01

    Water-extractable organic matter (WEOM) in soil affects contaminant mobility and toxicity, heterotrophic production, and nutrient cycling in terrestrial and aquatic ecosystems. This study focuses on the influences of land use history and agricultural management practices on the water extractability of organic matter and nutrients from soils. Water-extractable organic matter was extracted from soils under different crop rotations (an annual rotation of wheat-pea/bean-wheat-flax or a perennial-based rotation of wheat-alfalfa-alfalfa-flax) and management systems (organic or conventional) and examined for its concentration, composition, and biodegradability. The results show that crop rotations including perennial legumes increased the concentration of water-extractable organic carbon (WEOC) and water-extractable organic nitrogen (WEON) and the biodegradability of WEOC in soil but depleted the quantity of water-extractable organic phosphorus (WEOP) and water-extractable reactive phosphorus. The 30-d incubation experiments showed that bioavailable WEOC varied from 12.5% in annual systems to 22% for perennial systems. The value of bioavailable WEOC was found to positively correlate with WEON concentrations and to negatively correlate with C:N ratio and the specific ultraviolet absorbance of WEOM. No significant treatment effect was present with the conventional and organic management practices, which suggested that WEOM, as the relatively labile pool in soil organic matter, is more responsive to the change in crop rotation than to mineral fertilizer application. Our results indicated that agricultural landscapes with contrasting crop rotations are likely to differentially affect rates of microbial cycling of organic matter leached to soil waters. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Fine tuning of graphene properties by modification with aryl halogens

    Science.gov (United States)

    Bouša, D.; Pumera, M.; Sedmidubský, D.; Šturala, J.; Luxa, J.; Mazánek, V.; Sofer, Z.

    2016-01-01

    Graphene and its derivatives belong to one of the most intensively studied materials. The radical reaction using halogen derivatives of arene-diazonium salts can be used for effective control of graphene's electronic properties. In our work we investigated the influence of halogen atoms (fluorine, chlorine, bromine and iodine) as well as their position on the benzene ring towards the electronic and electrochemical properties of modified graphenes. The electronegativity as well as the position of the halogen atoms on the benzene ring has crucial influence on graphene's properties due to the inductive and mesomeric effects. The results of resistivity measurement are in good agreement with the theoretical calculations of electron density within chemically modified graphene sheets. Such simple chemical modifications of graphene can be used for controllable and scalable synthesis of graphene with tunable transport properties.Graphene and its derivatives belong to one of the most intensively studied materials. The radical reaction using halogen derivatives of arene-diazonium salts can be used for effective control of graphene's electronic properties. In our work we investigated the influence of halogen atoms (fluorine, chlorine, bromine and iodine) as well as their position on the benzene ring towards the electronic and electrochemical properties of modified graphenes. The electronegativity as well as the position of the halogen atoms on the benzene ring has crucial influence on graphene's properties due to the inductive and mesomeric effects. The results of resistivity measurement are in good agreement with the theoretical calculations of electron density within chemically modified graphene sheets. Such simple chemical modifications of graphene can be used for controllable and scalable synthesis of graphene with tunable transport properties. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06295k

  6. Micro-solid-phase extraction of organochlorine pesticides using porous metal-organic framework MIL-101 as sorbent.

    Science.gov (United States)

    Huang, Zhenzhen; Lee, Hian Kee

    2015-07-03

    In this study, a metal-organic framework material, MIL-101, used as a micro-solid-phase extraction (μ-SPE) sorbent for efficient enrichment of five organochlorine pesticides (OCPs), including α-HCH, Aldrin, α-Chlordane, Dieldrin and p,p'-DDD from water samples, followed by gas chromatography-mass spectrometry, is reported. This study demonstrated a new application of MIL-101 using μ-SPE, an advantage of the latter being its ability to process complex aqueous matrices, due to the protection of the sorbent afforded by the hollow fiber membrane bag. Key factors affecting extraction efficiency were studied, including elution solvent, extraction and desorption time. Under the optimal extraction conditions, the calibration plots were linear from 0.05 to 50 ng/mL for α-HCH and p,p'-DDD, and 0.1 to 50 ng/mL for the other three analytes. The limits of detection were between 0.0025 and 0.016 ng/mL. The relative recoveries of the OCPs spiked into real water samples (at 5 ng/mL of each analyte) ranged from 87.6 to 98.6% with relative standard deviations of <10%.

  7. Facile Synthesis of Magnetic Covalent Organic Framework with Three-Dimensional Bouquet-Like Structure for Enhanced Extraction of Organic Targets.

    Science.gov (United States)

    He, Sijing; Zeng, Tao; Wang, Saihua; Niu, Hongyun; Cai, Yaqi

    2017-01-25

    A facile strategy for the fabrication of novel bouquet-shaped magnetic porous nanocomposite via grafting a covalent organic framework (COF, TpPa-1) onto the surface-modified Fe3O4 nanoparticles (Fe3O4 NPs) was reported. The magnetic TpPa-1 (a COF synthesized from 1,3,5-triformylphloroglucinol (Tp) and p-phenylenediamine (Pa-1)) contains clusters of core-shell magnetic nanoparticles and interconnected porous TpPa-1 nanofibers. Thus, it possesses larger specific surface area, higher porosity, and supermagnetism, making it an ideal sorbent for enrichment of trace analytes. Its performance was evaluated by the magnetic solid-phase extraction (MSPE) of trace polycyclic aromatic hydrocarbons (PAHs) from environmental samples prior to high-performance liquid chromatographic analysis. The results indicated that the magnetic TpPa-1 possessed superior enrichment capacity of such organic compounds.

  8. Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions.

    Science.gov (United States)

    This study aimed to investigate the content of carbohydrates and amino compounds in three labile fraction of soil organic matter (SOM). Soil samples were collected from two agricultural fields in southern Italy and the light fraction (LF), the 500–53-µm particulate organic matter (POM) and the mobil...

  9. Facile Preparation of Molybdenum Bronzes as an Efficient Hole Extraction Layer in Organic Photovoltaics.

    Science.gov (United States)

    Wang, Jiantai; Zhang, Jun; Meng, Bin; Zhang, Baohua; Xie, Zhiyuan; Wang, Lixiang

    2015-06-24

    We proposed a facile and green one-pot strategy to synthesize Mo bronzes nanoparticles to serve as an efficient hole extraction layer in polymer solar cells. Mo bronzes were obtained through reducing the fractional self-aggregated ammonium heptamolybdate with appropriate reducing agent ascorbic acid, and its optoelectronic properties were fully characterized. The synthesized Mo bronzes displayed strong n-type semiconductor characteristics with a work function of 5.2-5.4 eV, matched well with the energy levels of current donor polymers. The presented gap states of the Mo bronzes near the Fermi level were beneficial for facilitating charge extraction. The as-synthesized Mo bronzes were used as hole extraction layer in polymer solar cells and significantly enhanced the photovoltaic performance and stability. The power conversion efficiency was increased by more than 18% compared with the polyethylene dioxythiophene:polystyrenesulfonate-based reference cell. The excellent performance and facile preparation render the as-synthesized solution-processed Mo bronzes nanoparticles a promising candidate for hole extraction layer in low-cost and efficient polymer solar cells.

  10. Competition between recombination and extraction of free charges determines the fill factor of organic solar cells

    NARCIS (Netherlands)

    Bartesaghi, Davide; Perez, Irene del Carmen; Kniepert, Juliane; Roland, Steffen; Turbiez, Mathieu; Neher, Dieter; Koster, L. Jan Anton

    Among the parameters that characterize a solar cell and define its power-conversion efficiency, the fill factor is the least well understood, making targeted improvements difficult. Here we quantify the competition between charge extraction and recombination by using a single parameter theta, and we

  11. Toxicological validation of a procedure for extracting organic micropollutants form water samples

    NARCIS (Netherlands)

    Vaal MA; Folkerts AJ; Kamp RE van de; Struijs J; ECO

    1999-01-01

    A procedure, developed to extract micropollutants from water samples into a concentrate that is suitable for the performance of aquatic toxicity tests, was toxicologically validated. Toxicity of known cocktail of toxicants concentrated to a level measurable in short-term toxicity tests was measured

  12. Toxicological validation of a procedure for extracting organic micropollutants form water samples

    NARCIS (Netherlands)

    Vaal MA; Folkerts AJ; Kamp RE van de; Struijs J; ECO

    1999-01-01

    A procedure, developed to extract micropollutants from water samples into a concentrate that is suitable for the performance of aquatic toxicity tests, was toxicologically validated. Toxicity of known cocktail of toxicants concentrated to a level measurable in short-term toxicity tests was measured

  13. Symmetric and asymmetric halogen-containing metallocarboranylporphyrins and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Michiko; Wu, Haitao

    2013-05-21

    The present invention is directed to low toxicity boronated compounds and methods for their use in the treatment, visualization, and diagnosis of tumors. More specifically, the present invention is directed to low toxicity halogenated, carborane-containing 5,10,15,20-tetraphenylporphyrin compounds and methods for their use particularly in boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) for the treatment of tumors of the brain, head and neck, and surrounding tissue. The invention is also directed to using these halogenated, carborane-containing tetraphenylporphyrin compounds in methods of tumor imaging and/or diagnosis such as MRI, SPECT, or PET.

  14. Characterization and beneficiation of the Egyptian black shale for possible extraction of organic matter

    Institute of Scientific and Technical Information of China (English)

    Abd El-Rahiem F.H.; Hassan M.S.; Selim K.A.; Abdel-Khalek N.A

    2014-01-01

    The present paper focuses on obtaining concentrate enriched with organic matter that could be suitable for a retorting process from black shale; this is black shale from the Safaga area on the Red Sea Coast. X-ray diffraction and optical polarising microscope are used in evaluating black shale minerals. Attrition scrubbing and flotation were conducted for enrichment of organic matter in the black shale sample. Mineralogical studies revealed that black shale samples contain bituminous calcareous clay stone, quartz, apatite and pyrite. Rabah mine black shale contains 28% organic matter. The results of the different separation techniques indicate that attrition and flotation techniques successively enriched the organic matter in the black shale. The organic matter could be enriched in the black shale and obtained a concen-trate with 59%assaying and 85%recovery.

  15. 40 CFR 721.785 - Halogenated alkane aromatic compound (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated alkane aromatic compound... Specific Chemical Substances § 721.785 Halogenated alkane aromatic compound (generic name). (a) Chemical... as a halogenated alkane aromatic compound (PMN P-94-1747) is subject to reporting under this...

  16. ON DEVELOPING CLEANER ORGANIC UNIT PROCESSES

    Science.gov (United States)

    Organic waste products, potentially harmful to the human health and the environment, are primarily produced in the synthesis stage of manufacturing processes. Many such synthetic unit processes, such as halogenation, oxidation, alkylation, nitration, and sulfonation are common to...

  17. Assembling supramolecular networks by halogen bonding in coordination polymers driven by 5-bromonicotinic acid

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Jin-Zhong, E-mail: gujzh@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Wu, Jiang [State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Kirillov, Alexander M. [Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, The University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Lv, Dong-Yu; Tang, Yu; Wu, Jin-Cai [State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

    2014-05-01

    A series of six coordination compounds ([Zn(5-Brnic){sub 2}]·1.5H{sub 2}O){sub n} (1), [Cd(5-Brnic){sub 2}]{sub n} (2), [Co(5-Brnic){sub 2}(H{sub 2}O){sub 2}]{sub n} (3), [Zn(5-Brnic){sub 2}(H{sub 2}biim)]{sub n} (4), ([Cd(5-Brnic){sub 2}(phen)]·H{sub 2}O){sub n} (5), and [Pb(5-Brnic){sub 2}(phen)] (6) have been generated by the hydrothermal method from the metal(II) nitrates, 5-bromonicotinic acid (5-BrnicH), and an optional ancillary 1,10-phenanthroline (phen) or 2,2′-biimidazole (H{sub 2}biim) ligand. All the products 1–6 have been characterized by IR spectroscopy, elemental, thermal, powder and single-crystal X-ray diffraction analyses. Their 5-bromonicotinate-driven structures vary from the 3D metal-organic framework with the seh-3,5-P21/c topology (in 2) and the 2D interdigitated layers with the sql topology (in 1 and 3), to the 1D chains (in 4 and 5) and the 0D discrete monomers (in 6). The 5-bromonicotinate moiety acts as a versatile building block and its tethered bromine atom plays a key role in reinforcing and extending the structures into diverse 3D supramolecular networks via the various halogen bonding Br⋯O, Br⋯Br, and Br⋯π interactions, as well as the N–H⋯O and C–H⋯O hydrogen bonds. The obtained results demonstrate a useful guideline toward engineering the supramolecular architectures in the coordination network assembly under the influence of various halogen bonding interactions. The luminescent (for 1, 2, 4, 5, and 6) and magnetic (for 3) properties have also been studied and discussed in detail. - Graphical abstract: Six coordination compounds driven by 5-bromonicotinic acid have been generated and structurally characterized, revealing diverse metal-organic networks that are further reinforced and extended via various halogen bonding interactions. - Highlights: • 5-Bromonicotinic acid is a versatile ligand for Zn, Cd, Co and Pb derivatives. • Careful selection of co-ligands and metals resulted in different network

  18. Did the Siberian Traps eruptions emit enough halogens to have an impact on ozone geochemistry?

    Science.gov (United States)

    Sibik, Svetlana; Edmonds, Marie; Villemant, Benoit; Thierry, Pauline; Polozov, Alexander

    2015-04-01

    The Siberian Traps Large Igneous Province is thought to have formed over 1 Ma at the end of the Permian, synchronous with the largest mass extinction in Earth's history. There remains much controversy as to the exact mechanism of the mass extinction, but all hypotheses revolve around the emission of volatiles in various forms. The research to date has tended to focus on sulfur and carbon rather than halogen degassing, despite this being probably critical in terms of environmental impact as they might have been played a crucial role in ozone layer depletion and therefore promote mass extinction. Current study aims to look at the behaviour of chlorine, bromine, iodine and fluorine to evaluate the halogen budget contribution from heterogeneous mantle source and from evaporates, which dominate in the south (Cambrian evaporites) and north (Devonian evaporites) of Siberian platform. For this study we use basaltic sills and lava flows emplaced in the area with no volatile-rich sediments south-east from Norilsk (Dyupkin lake and Lower Tunguska river regions) and a sill intruded into evaporates in Nepa location in the south of the platform, originally aimed at prospecting for potassium salts. Borehole samples of basalts intruded into evaporites might have been penetrated by salts and anhydrite. In order to eliminate this effect and ensure that we analyse halogen contents in pure basalts prior to any further analysis the samples were specifically treated so that penetrated material was removed as leachates. Whole rock fine powders of basalts were analysed for halogens, major and trace elements. The solutions obtained by basalt pyrohydrolysis extraction, leachates of basaltic powders and dissolved evaporites were analysed by ion chromatography for chlorine and fluorine and by ICP-MS for bromine and iodine. Basalts intruded into evaporites demonstrate predicted pronounced chlorine, bromine and iodine enrichments associated with salt assimilation. The results show that bromine

  19. Quantitative determination of volatile organic compounds (VOC) in milk by multiple dynamic headspace extraction and GC-MS.

    Science.gov (United States)

    Ciccioli, Paolo; Brancaleoni, Enzo; Frattoni, Massimiliano; Fedele, Vincenzo; Claps, Salvatore; Signorelli, Federica

    2004-01-01

    A method for the accurate determination of volatile organic compounds (VOC) in milk samples has been developed and tested. It combines multiple dynamic headspace extraction with GC-MS. Absolute amounts of VOC in the liquid phase are obtained by determining the first order kinetic dependence of the stepwise extraction of the analytes and internal standards from the liquid matrix. Compounds released from milk were collected on a train of traps filled with different solid sorbents to cover all components having a number of carbon atoms ranging from 4 to 15. They were analysed by GC-MS after thermal desorption of VOC from the collecting traps. Quantification of VOC in milk was performed using deuterated compounds as internal standards. The method was used to follow seasonal variations of monoterpenes in goat milk and to detect the impact of air pollution on the quality of milk.

  20. DNA extraction techniques compared for accurate detection of genetically modified organisms (GMOs) in maize food and feed products.

    Science.gov (United States)

    Turkec, Aydin; Kazan, Hande; Karacanli, Burçin; Lucas, Stuart J

    2015-08-01

    In this paper, DNA extraction methods have been evaluated to detect the presence of genetically modified organisms (GMOs) in maize food and feed products commercialised in Turkey. All the extraction methods tested performed well for the majority of maize foods and feed products analysed. However, the highest DNA content was achieved by the Wizard, Genespin or the CTAB method, all of which produced optimal DNA yield and purity for different maize food and feed products. The samples were then screened for the presence of GM elements, along with certified reference materials. Of the food and feed samples, 8 % tested positive for the presence of one GM element (NOS terminator), of which half (4 % of the total) also contained a second element (the Cauliflower Mosaic Virus 35S promoter). The results obtained herein clearly demonstrate the presence of GM maize in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of maize food and feed products.

  1. A new extraction method to assess the environmental availability of ciprofloxacin in agricultural soils amended with exogenous organic matter.

    Science.gov (United States)

    Goulas, Anaïs; Haudin, Claire-Sophie; Bergheaud, Valérie; Dumény, Valérie; Ferhi, Sabrina; Nélieu, Sylvie; Bourdat-Deschamps, Marjolaine; Benoit, Pierre

    2016-12-01

    Fluoroquinolone antibiotics such as ciprofloxacin can be found in soils receiving exogenous organic matter (EOM). Their long-term behavior in EOM-amended soils and their level of biodegradability are not well understood partly due to a lack of methods to estimate their environmental availability. We performed different aqueous extractions to quantify the available fraction of (14)C-ciprofloxacin in soils amended with a compost of sewage sludge and green wastes or a farmyard manure contaminated at relevant environmental concentrations. After minimizing (14)C-ciprofloxacin losses by adsorption on laboratory vessel tubes, three out of eleven different aqueous solutions were selected, i.e., Borax, Na2EDTA and 2-hydroxypropyl-β-cyclodextrin. During 28 d of incubation, the non-extractable fractions were very high in all samples, i.e., 57-67% of the initial (14)C-activity, and the availability of the antibiotic was very low, explaining its low biodegradation. A maximum of 6.3% of the initial (14)C-activity was extracted from soil/compost mixtures with the Na2EDTA solution, and 7.2% from soil/manure mixtures with the Borax solution. The available fraction level was stable over the incubation in soil/compost mixtures but slightly varied in soil/manure mixtures following the organic matter decomposition. The choice of different soft extractants highlighted different sorption mechanisms controlling the environmental availability of ciprofloxacin, where the pH and the quality of the applied EOM appeared to be determinant. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Pyrethroid residue determination in organic and conventional vegetables using liquid-solid extraction coupled with magnetic solid phase extraction based on polystyrene-coated magnetic nanoparticles.

    Science.gov (United States)

    Yu, Xi; Yang, Hongshun

    2017-02-15

    A detection method using polystyrene-coated magnetic nanoparticles based extraction technique coupled to HPLC was developed for trace amount of pyrethroids residue detection in vegetable matrixes. The recoveries for five kinds of commonly used pyrethroids were in the range of 91.6%-116.2%. The sensitivity and precision of the method were satisfactory with the limits of detection and limits of quantification in the range of 0.0200-0.0392ngg(-1) and 0.072-0.128ngg(-1), respectively. The intra-day and inter-day relative standard deviations for the recoveries of the analytes were lower than 6.8% and 10.7%, respectively. The nanoparticles can be washed and recycled after use. The results indicate that the developed method was efficient, fast, economical and environmentally friendly. The method was successfully applied to detect the pyrethroids residue in ten pairs of commonly consumed organic and conventional fresh vegetables in Singapore. Pyrethroids residue was detected in four kinds of conventional vegetables and one kind of organic vegetable.

  3. Halogen and Cl isotopic systematics in Martian phosphates: Implications for the Cl cycle and surface halogen reservoirs on Mars

    Science.gov (United States)

    Bellucci, J. J.; Whitehouse, M. J.; John, T.; Nemchin, A. A.; Snape, J. F.; Bland, P. A.; Benedix, G. K.

    2017-01-01

    The Cl isotopic compositions and halogen (Cl, F, Br, and I) abundances in phosphates from eight Martian meteorites, spanning most rock types and ages currently available, have been measured in situ by Secondary Ion Mass Spectrometry (SIMS). Likewise, the distribution of halogens has been documented by x-ray mapping. Halogen concentrations range over several orders of magnitude up to some of the largest concentrations yet measured in Martian samples or on the Martian surface, and the inter-element ratios are highly variable. Similarly, Cl isotope compositions exhibit a larger range than all pristine terrestrial igneous rocks. Phosphates in ancient (>4 Ga) meteorites (orthopyroxenite ALH 84001 and breccia NWA 7533) have positive δ37Cl anomalies (+1.1 to + 2.5 ‰). These samples also exhibit explicit whole rock and grain scale evidence for hydrothermal or aqueous activity. In contrast, the phosphates in the younger basaltic Shergottite meteorites (<600 Ma) have negative δ37Cl anomalies (-0.2 to - 5.6 ‰). Phosphates with the largest negative δ37Cl anomalies display zonation in which the rims of the grains are enriched in all halogens and have significantly more negative δ37Cl anomalies suggestive of interaction with the surface of Mars during the latest stages of basalt crystallization. The phosphates with no textural, major element, or halogen enrichment evidence for mixing with this surface reservoir have an average δ37Cl of - 0.6 ‰, supporting a similar initial Cl isotope composition for Mars, the Earth, and the Moon. Oxidation and reduction of chlorine are the only processes known to strongly fractionate Cl isotopes, both positively and negatively, and perchlorate has been detected in weight percent concentrations on the Martian surface. The age range and obvious mixing history of the phosphates studied here suggest perchlorate formation and halogen cycling via brines, which have been documented on the Martian surface, has been active throughout Martian

  4. Effects of aerosol collection and extraction procedures on the optical properties of water-soluble organic compounds

    Science.gov (United States)

    Mladenov, N.; Alados-Arboledas, L.; Olmo Reyes, F. J.; Reche, I.

    2009-12-01

    Water-soluble organic compounds (WSOC) are routinely collected using active and passive aerosol samplers and, after extraction in water, analyzed using UV-vis absorbance and fluorescence techniques. These analyses provide important information regarding the chemical character and sources of aerosols worldwide. To evaluate the effects of various aerosol collection and processing methods on the optical properties of WSOC, two-dimensional absorption spectra from 200 to 900 nm and three-dimensional fluorescence excitation-emission spectra (EEMs) from 240 to 450 nm excitation and 300 to 560 nm emission were analyzed in samples obtained simultaneously with different procedures. Samples included: milli-Q purified water passed through 140 mm diameter glass fiber and quartz fiber filters used in high volume PM10 aerosol samplers, 47 mm glass fiber filters used for organic matter analyses, and mixed cellulose 0.2 micron and 0.015 micron filters used for bacterial and viral filtration, respectively; milli-Q purified water rinsed in plastic buckets used for passive wet and dry deposition collection; and WSOC samples extracted from filters by soaking, sonication, and agitation. Parallel factor analysis (PARAFAC) modeling of WSOC was performed to quantify the influence of various collection and extraction procedures on fluorescence signatures. All filters examined were found to leach some amount of fluorescent compounds (Figure 1). Mixed cellulose filters, especially those with small pore size, leached substantially more amino acid-like and humic-like material than other filters, whereas leaching from quartz fiber filters used for high volume aerosol collection was minimal (Figure 1). Fluorescence intensities of filter leachates decreased with increased rinsing of filters, indicating that rinsing with purified water prior to filtration is advisable, even for pre-combusted filters. Dissolved organic carbon concentrations of WSOC extracted from filters by sonication, agitation

  5. Ozone variability and halogen oxidation within the Arctic and sub-Arctic springtime boundary layer

    Directory of Open Access Journals (Sweden)

    J. B. Gilman

    2010-11-01

    Full Text Available The influence of halogen oxidation on the variabilities of ozone (O3 and volatile organic compounds (VOCs within the Arctic and sub-Arctic atmospheric boundary layer was investigated using field measurements from multiple campaigns conducted in March and April 2008 as part of the POLARCAT project. For the ship-based measurements, a high degree of correlation (r = 0.98 for 544 data points collected north of 68° N was observed between the acetylene to benzene ratio, used as a marker for chlorine and bromine oxidation, and O3 signifying the vast influence of halogen oxidation throughout the ice-free regions of the North Atlantic. Concurrent airborne and ground-based measurements in the Alaskan Arctic substantiated this correlation and were used to demonstrate that halogen oxidation influenced O3 variability throughout the Arctic boundary layer during these springtime studies. Measurements aboard the R/V Knorr in the North Atlantic and Arctic Oceans provided a unique view of the transport of O3-poor air masses from the Arctic Basin to latitudes as far south as 52° N. FLEXPART, a Lagrangian transport model, was used to quantitatively determine the exposure of air masses encountered by the ship to first-year ice (FYI, multi-year ice (MYI, and total ICE (FYI+MYI. O3 anti-correlated with the modeled total ICE tracer (r = −0.86 indicating that up to 73% of the O3 variability measured in the Arctic marine boundary layer could be related to sea ice exposure.

  6. Towards Automatic Extraction of Social Networks of Organizations in PubMed Abstracts

    CERN Document Server

    Jonnalagadda, Siddhartha; Gonzalez, Graciela

    2010-01-01

    Social Network Analysis (SNA) of organizations can attract great interest from government agencies and scientists for its ability to boost translational research and accelerate the process of converting research to care. For SNA of a particular disease area, we need to identify the key research groups in that area by mining the affiliation information from PubMed. This not only involves recognizing the organization names in the affiliation string, but also resolving ambiguities to identify the article with a unique organization. We present here a process of normalization that involves clustering based on local sequence alignment metrics and local learning based on finding connected components. We demonstrate the application of the method by analyzing organizations involved in angiogenensis treatment, and demonstrating the utility of the results for researchers in the pharmaceutical and biotechnology industries or national funding agencies.

  7. Calcium chloride electron injection/extraction layers in organic electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Bo, E-mail: bqu@pku.edu.cn, E-mail: qhgong@pku.edu.cn; Gao, Zhi; Yang, Hongsheng; Xiao, Lixin; Chen, Zhijian; Gong, Qihuang, E-mail: bqu@pku.edu.cn, E-mail: qhgong@pku.edu.cn [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China)

    2014-01-27

    Nontoxic calcium chloride (CaCl{sub 2}) was introduced into organic electronic devices as cathode buffer layer (CBL). The turn-on voltage and maximum luminance of organic light-emitting diode (OLED) with 1.5 nm CaCl{sub 2} was 3.5 V and 21 960 cd/m{sup 2}, respectively. OLED with 1.5 nm CaCl{sub 2} possessed comparable electroluminescent characteristics to that of the commonly used LiF. Moreover, the performance of the organic photovoltaic device with 0.5 nm CaCl{sub 2} was comparable to that of the control device with LiF. Therefore, CaCl{sub 2} has the potential to be used as the CBL for organic electronic devices.

  8. Evaluation of Genotoxic and Mutagenic Activity of Organic Extracts from Drinking Water Sources

    National Research Council Canada - National Science Library

    Guan, Ying; Wang, Xiaodong; Wong, Minghung; Sun, Guoping; An, Taicheng; Guo, Jun; Zhang, Guoxia

    2017-01-01

      An increasing number of industrial, agricultural and commercial chemicals in the aquatic environment lead to various deleterious effects on organisms, which is becoming a serious global health concern...

  9. Characterisation of solvent extractable organic constituents in atmospheric particulate matter: an overview

    National Research Council Canada - National Science Library

    Alves, Célia A

    2008-01-01

    In spite of accounting for 10-70% of the atmospheric aerosol mass, particulate-phase organic compounds are not well characterised, and many aspects of aerosol formation and evolution are still unknown...

  10. Organ specific metabolic activation of five extracts of indoor and outdoor particulate matter.

    Science.gov (United States)

    van Houdt, J J; Coenen, P W; Alink, G M; Boleij, J S; Koeman, J H

    1988-01-01

    In this study liver and lung homogenates of untreated and Aroclor 1254-pretreated rats (Wistar) and mice (Swiss) were compared for their P-450 content and their capacity to activate extracts of airborne particulate matter, sampled indoors and outdoors. Results show that in addition to liver, lung homogenates of rat (Wistar) and mouse (Swiss) are also able to activate extracts of airborne particulate matter in a comparative way. Uninduced liver and lung homogenates showed only minor differences in activation capacity in the metabolism of airborne particles. In contrast to liver homogenates, Aroclor 1254 pretreatment of test animals did not give strong induction of metabolic activation capacity of lung homogenates. P-450 content was observed in all liver and lung homogenates of mouse and rat and in human lung homogenates. The results obtained in this study suggest that the respiratory tract may be an important site for in vivo bioactivation of respirable particles.

  11. Use of grape seed and its natural polyphenol extracts as a natural organic coagulant for removal of cationic dyes.

    Science.gov (United States)

    Jeon, Jong-Rok; Kim, Eun-Ju; Kim, Young-Mo; Murugesan, Kumarasamy; Kim, Jae-Hwan; Chang, Yoon-Seok

    2009-11-01

    Natural organic coagulants (NOCs) such as chitosan and Moringa oleifera seeds have been extensively characterized for potential application in water treatment as an alternative to metal-based coagulants. However, the action of both chitosan and M. oleifera seeds is mainly restricted to anionic organic pollutants because of their cationic functional groups affording poor cationic pollutant coagulation by electrostatic repulsion. In this study, we employed ethanolic grape seed extract (GSE) and grape seed-derived polyphenols such as tannic acid and catechin in an effort to find novel NOCs showing stable anionic forms for removal of cationic organic pollutants. The target substances tested were malachite green (MG) and crystal violet (CV), both mutagenic cationic dyes. Polyphenol treatment induced fast decolorization followed by gradual floc formation concomitant with red or blue shifts in maximum absorbance wavelengths of the cationic dyes. Liquid chromatography analysis of flocs formed by polyphenols directly showed that initial supramolecular complexes attributed mainly to electrostatic attraction between polyphenol hydroxyphenyl groups and cationic dyes further progressed into stronger aggregates, leading to precipitation of dye-polyphenol complexes. Consistent with the results obtained using catechin and tannic acid, use of GSE also resulted in effective decolorization and coagulation of soluble MG and CV in aqueous solutions. Screening of several organic GSE components for NOC activity strongly suggested that natural polyphenols are the main organic ingredients causing MG and CV removal via gradual floc formation. The treatment by natural polyphenols and GSE decreased toxicity of MG- or CV-contaminated water.

  12. Aqueous and organic extracts of Trigonellafoenum-graecum L. Inhibit the mycelia growth of fungi

    Institute of Scientific and Technical Information of China (English)

    R. HAOUALA; S. HAWALA; A. EL-AYEB; R. KHANFIR; N. BOUGHANMI

    2008-01-01

    Aqueous extracts from various plant parts of fenugreek (3%) (aerial parts: leaves and stems (LS), roots (R), ground seeds (GS) and not ground seeds (NGS)) and petroleum ether, ethyl acetate and methanolic fractions of the aerial parts were assayed to determine their antifungal potential against Botrytis cinema, Fusarium graminearum, Alternaria sp., Pythium aphanidermatum, and Rhizoctinia solani. All fenugreek plant parts showed antifungal potential and the magnitude of their inhibitory effects was species and plant parts dependent. R extract was shown less toxic (30.38%), whereas NGS extract expressed the strongest inhibition, with an average of 71.44%, followed by GS (58.56%) and LS (57.1%). Screening indicated that P. aphanidermatum was the most resistant species, with an average inhibition of 34.5%. E graminearum, Alternaria sp. and R. solani were the most sensitive species, and were similarly inhibited (63.5%). The stability test indicated that the aqueous extracts of all plant parts lost approximately 50% of their relative activity after one month of storage at 4℃, whilst they lost 60%-90% of their activity when stored at ambient temperature for one month. The antifungal activity resided mainly in the methanol fraction and the minimum inhibitory concentration (MIC) of methanol fraction witch caused total inhibition of R. solani and Alternaria sp. was 60 μg/ml. Results of current study suggested that the constituents of Trigonella foenum-graecum have potential against harmful pathogenic fungi. Therefore, fenugreek could be an important source of biologically active compounds useful for developing better new antifungal drugs.

  13. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

    Science.gov (United States)

    The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

  14. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING SOLID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.20)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting and concentrating solid food samples for persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, substituted phenols, and...

  15. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING LIQUID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.19)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

  16. EPA Method 525.3 - Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS)

    Science.gov (United States)

    Method 525.3 is an analytical method that uses solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) for the identification and quantitation of 125 selected semi-volatile organic chemicals in drinking water.

  17. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING SOLID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.20)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting and concentrating solid food samples for persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, substituted phenols, and...

  18. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING LIQUID FOOD SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP-5.19)

    Science.gov (United States)

    This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

  19. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

    Science.gov (United States)

    The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

  20. The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

    Directory of Open Access Journals (Sweden)

    Kari Raatikainen

    2010-01-01

    Full Text Available The series of haloanilinium and halopyridinium salts: 4-IPhNH3Cl (1, 4-IPhNH3Br (5, 4-IPhNH3H2PO4 (6, 4-ClPhNH3H2PO4 (8, 3-IPyBnCl (9, 3-IPyHCl (10 and 3-IPyH-5NIPA (3-iodopyridinium 5-nitroisophthalate, 13, where hydrogen or/and halogen bonding represents the most relevant non-covalent interactions, has been prepared and characterized by single crystal X-ray diffraction. This series was further complemented by extracting some relevant crystal structures: 4-BrPhNH3Cl (2, CCDC ref. code TAWRAL, 4-ClPhNH3Cl (3, CURGOL, 4-FPhNH3Cl (4, ANLCLA, 4-BrPhNH3H2PO4, (7, UGISEI, 3-BrPyHCl, (11, CIHBAX and 3-ClPyHCl, (12, VOQMUJ from Cambridge Structural Database for sake of comparison. Based on the X-ray data it was possible to highlight the balance between non-covalent forces acting in these systems, where the relative strength of the halogen bonding C–X···A− (X = I, Br or Cl and the ratio between the halogen and hydrogen bonds [C–X···A− : D–H···A−] varied across the series.

  1. The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts.

    Science.gov (United States)

    Raatikainen, Kari; Cametti, Massimo; Rissanen, Kari

    2010-01-15

    THE SERIES OF HALOANILINIUM AND HALOPYRIDINIUM SALTS: 4-IPhNH₃Cl (1), 4-IPhNH₃Br (5), 4-IPhNH₃H₂PO₄ (6), 4-ClPhNH₃H₂PO₄ (8), 3-IPyBnCl (9), 3-IPyHCl (10) and 3-IPyH-5NIPA (3-iodopyridinium 5-nitroisophthalate, 13), where hydrogen or/and halogen bonding represents the most relevant non-covalent interactions, has been prepared and characterized by single crystal X-ray diffraction. This series was further complemented by extracting some relevant crystal structures: 4-BrPhNH₃Cl (2, CCDC ref. code TAWRAL), 4-ClPhNH₃Cl (3, CURGOL), 4-FPhNH₃Cl (4, ANLCLA), 4-BrPhNH₃H₂PO₄, (7, UGISEI), 3-BrPyHCl, (11, CIHBAX) and 3-ClPyHCl, (12, VOQMUJ) from Cambridge Structural Database for sake of comparison. Based on the X-ray data it was possible to highlight the balance between non-covalent forces acting in these systems, where the relative strength of the halogen bonding C-X...A⁻ (X = I, Br or Cl) and the ratio between the halogen and hydrogen bonds [C-X...A⁻ : D-H...A⁻] varied across the series.

  2. Racemic ofloxacin separation by supported-liquid membrane extraction with two organic phases

    Institute of Scientific and Technical Information of China (English)

    唐课文; 周春山; 蒋新宇

    2003-01-01

    Based on chemical thermodynamic theory, racemic ofloxacin is separatedin chiral systems by hollow fiber liquid-supported membrane technology combining with countercurrently fractional extraction. The two chiral solutions containing L-dibenzoyltartaric acid and D-dibenzoylta- rtaric acid in 1-octanol, flow through the lumen side and the shell side of fibers, respectively. The solution which flows through the lumen side of fibers also contains racemic ofloxacin. The wall of hollow fibers is filled with an aqueous of 0.1 mol/L Na2HPO4/H3PO4 buffer solution of pH = 6.86 containing 2 mmol/L of cetyltrimethyl ammonium bromide for 48 h. The fairly polar ofloxacin can cross the membrane back and forth, but dibenzoyltartaric acids cannot cross it. Fractional chiral extraction theory, mass transfer performance of hollow fiber membrane and enantioselectivity are investigated. Mathematical model of R/S = 0.96e0.03NTU for racemic ofloxacin separation by hollow fiber extraction, is established. The optical purity for ofloxacin enantiomers is up to 90% when 11 hollow fiber membrane modules of 22 cm in length in series are used.

  3. Exploration of Islamic medicine plant extracts as powerful antifungals for the prevention of mycotoxigenic Aspergilli growth in organic silage

    DEFF Research Database (Denmark)

    Tayel, Ahmed A.; Salem, Mohammed F.; El-Tras, Wael F.

    2011-01-01

    Feed contamination with mycotoxins is a major risk factor for animals and humans as several toxins can exist as residues in meat and milk products, giving rise to carry-over to consumers via ingestion of foods of animal origin. The starting point for prevention, in this chain, is to eliminate the...... the growth of mycotoxigenic fungi in the animal forage. Ten plant extracts, recommended in Islamic medicine, were evaluated as antifungal agents against mycotoxigenic Aspergilli, i.e. Aspergillus flavus and A. ochraceus, growth in organic maize silage....

  4. Solid phase extraction method for the study of black carbon cycling in dissolved organic carbon using radiocarbon

    OpenAIRE

    2015-01-01

    © 2015 Elsevier B.V.. Radiocarbon analysis is a powerful tool for understanding the cycling of individual components within carbon pools, such as black carbon (BC) in dissolved organic carbon (DOC). Radiocarbon (δ14C) measurements of BC in DOC provide insight into one source of aged, recalcitrant DOC. We report a modified solid phase extraction (SPE) method to concentrate 43±6% of DOC (SPE-DOC) from seawater. We used the Benzene Polycarboxylic Acid (BPCA) method to isolate BC from SPE-DOC (SP...

  5. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DERMAL WIPE SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.16)

    Science.gov (United States)

    The method for extracting and preparing a dermal (hand) wipe sample for analysis of neutral persistent organic pollutants is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  6. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING SURFACE WIPE FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.17)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a hard floor surface wipe or food preparation surface wipe sample for analysis of neutral persistent organic. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spect...