Science.gov

Sample records for compounds determine effects

  1. Determination of an Effective Perfluorinated Compounds (PFCs) Oxidation Method

    NASA Astrophysics Data System (ADS)

    Siriwardena, D. P.; Crimi, M.; Holsen, T.; Bellona, C.

    2014-12-01

    Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a stable synthetic class of chemicals ubiquitously spread in environmental media (i.e. air, soil, biota, surface water and groundwater). The substances' strong polar carbon-fluorine bonds and their high thermal and chemical stability make them resistant to biological, chemical, and physical degradation. The purpose of this research is to identify the most effective oxidation method to treat perfluorinated compounds (PFCs) and their by-products that is suitable for in situ application. The laboratory oxidation study focuses on the more commonly detected and studied long-chain (C-8) PFAS; perfluorooctanoic acids (PFOA) and perfluorooctane sulfonic acid (PFOS). Existing research evaluating oxidizing treatment effectiveness on perfluoroalkyl sulfoinoic acids (PFSAs) is limited. A review of the literature and results from preliminary studies indicate that activated persulfate and catalyzed hydrogen peroxide propagation (CHP) reactions appear to be promising oxidants for PFOA. It has been demonstrated that the reactivity of superoxide in water increases in the presence of hydrogen peroxide (H2O2) and solids. Superoxide generated in CHP reactions degrades PFOA seemingly similar to superoxide-mediated destruction of the perhalogenated compounds.The goal of this study is to look at conditions that promote generation of superoxide and look at PFASs treatment effectiveness and byproduct generation. CHP reactions are conducted with varying amount of H2O2 and Fe(III) to determine the optimum conditions for PFC degradation. Results will be compared to those of another experiment using manganese dioxide as a CHP catalyst with varied H2O2 concentration to generate superoxide to degrade PFASs. Activated persulfate conditions to be compared include alkaline pH activation, heat activation, and dual oxidation (combined H2O2 and persulfate ). This presentation will focus on a comparison of oxidation effectiveness under the

  2. Determining inhibition effects of some aromatic compounds on peroxidase enzyme purified from white and red cabbage

    NASA Astrophysics Data System (ADS)

    Öztekin, Aykut; Almaz, Züleyha; Özdemir, Hasan

    2016-04-01

    Peroxidases (E.C.1.11.1.7) catalyze the one electron oxidation of wide range of substrates. They are used in synthesis reaction, removal of peroxide from industrial wastes, clinical biochemistry and immunoassays. In this study, the white cabbage (Brassica Oleracea var. capitata f. alba) and red cabbage (Brassica oleracea L. var. capitata f. rubra) peroxidase enzymes were purified for investigation of inhibitory effect of some aromatic compounds on these enzymes. IC50 values and Ki constants were calculated for the molecules of 6-Amino nicotinic hydrazide, 6-Amino-5-bromo nicotinic hydrazide, 2-Amino-5-hydroxy benzohydrazide, 4-Amino-3-hydroxy benzohydrazide on purified enzymes and inhibition type of these molecules were determined. (This research was supported by Ataturk University. Project Number: BAP-2015/98).

  3. Active machine learning-driven experimentation to determine compound effects on protein patterns

    PubMed Central

    Naik, Armaghan W; Kangas, Joshua D; Sullivan, Devin P; Murphy, Robert F

    2016-01-01

    High throughput screening determines the effects of many conditions on a given biological target. Currently, to estimate the effects of those conditions on other targets requires either strong modeling assumptions (e.g. similarities among targets) or separate screens. Ideally, data-driven experimentation could be used to learn accurate models for many conditions and targets without doing all possible experiments. We have previously described an active machine learning algorithm that can iteratively choose small sets of experiments to learn models of multiple effects. We now show that, with no prior knowledge and with liquid handling robotics and automated microscopy under its control, this learner accurately learned the effects of 48 chemical compounds on the subcellular localization of 48 proteins while performing only 29% of all possible experiments. The results represent the first practical demonstration of the utility of active learning-driven biological experimentation in which the set of possible phenotypes is unknown in advance. DOI: http://dx.doi.org/10.7554/eLife.10047.001 PMID:26840049

  4. Study of the Effect of Surfactants on Extraction and Determination of Polyphenolic Compounds and Antioxidant Capacity of Fruits Extracts

    PubMed Central

    Hosseinzadeh, Reza; Khorsandi, Khatereh; Hemmaty, Syavash

    2013-01-01

    Micelle/water mixed solutions of different surface active agents were studied for their effectiveness in the extraction of polyphenolic compounds from various varieties of apples from west Azerbaijan province in Iran. The total content of polyphenolic compound in fruit extracts were determined using ferrous tartrate and Folin–Ciocalteu assays methods and chromatographic methods and compared with theme. High performance liquid chromatography is one of the most common and important methods in biochemical compound identification. The effect of pH, ionic strength, surfactant type, surfactant concentration, extraction time and common organic solvent in the apple polyphenolics extractions was studied using HPLC-DAD. Mixtures of surfactants, water and methanol at various ratios were examined and micellar-water solutions of Brij surfactant showed the highest polyphenol extraction efficiency. Optimum conditions for the extraction of polyphenolic compounds from apple occurred at 7 mM Brij35, pH 3. Effect of ionic strength on extraction was determined and 2% (W/V) potassium Chloride was determined to be the optimum salt concentration. The procedure worked well with an ultrasound bath. Total antioxidant capacity also was determined in this study. The method can be safely scaled up for pharmaceutical applications. PMID:23472082

  5. VOLATILE ORGANIC COMPOUND DETERMINATIONS USING SURROGATE-BASED CORRECTION FOR METHOD AND MATRIX EFFECTS

    EPA Science Inventory

    The principal properties related to analyte recovery in a vacuum distillate are boiling point and relative volatility. The basis for selecting compounds to measure the relationship between these properties and recovery for a vacuum distillation is presented. Surrogates are incorp...

  6. Determination of mass attenuation coefficients and effective atomic numbers for compounds of the 3d transition elements

    NASA Astrophysics Data System (ADS)

    Yılmaz, Demet; Boydaş, Elif; Cömert, Esra

    2016-08-01

    In this study, we aimed to determine mass attenuation coefficient (μm) and effective atomic number (Zeff) for some compounds of the 3d transition elements such as CoO, CoF2, CoF3, Cr2O3, CrF2, CrF3, FeO, Fe2O3, MnO2, TiO2, V2O3, VF3, V2O5, VF4 and ZnO at 19.63 and 22.10 keV photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. The experimental results of μm are compared with the theoretical results. Also, effective atomic numbers of compounds of the 3d transition elements have been determined by using experimental and theoretical mass attenuation coefficients. The agreement of measured values of effective atomic numbers with theoretical calculations is quite satisfactory.

  7. Determining the Effect of Concerted Elimination Reactions in the Pyrolysis of Lignin Using Model Compounds

    SciTech Connect

    Robichaud, D.; Clark, J.; Nimlos, M.

    2012-01-01

    Lignin pyrolysis is a significant impediment in forming liquid fuel from biomass. Lignin pyrolyzes at a higher temperature than other biomass components (ie cellulose, hemicellulose) and tends to form radicals which lead to cross linking and ultimately char formation. A primary step in advances biomass-to-fuel technology will be to discover mechanisms that can disassemble lignin at lower temperatures and depolymerize lignin into more stable products. We have investigated the thermochemistry of the various inter-linkage units found in lignin ({beta}-O4, {alpha}-O4, {beta}-{beta}, {beta}-O5, etc) using electronic structure calculations at the M06-2x/6-311++G(d,p) on a series of dimer model compounds. In addition to the usually-assumed bond homolysis reactions, we have investigated a variety of concerted elimination pathways that will tend to produce closed-shell stable products. Such a bottom-up approach could aid in the targeted development of catalysts that produce more desirable products under less severe reactor conditions.

  8. [Health effects of solar cell component material. Toxicity of indium compounds to laboratory animals determined by intratracheal instillations].

    PubMed

    Tanaka, Akiyo; Hirata, Miyuki

    2013-01-01

    Owing to the increasing interest being paid to the issue of the global environment, the production of solar cells has increased rapidly in recent years. Copper indium gallium diselenide (CIGS) is a new efficient thin film used in some types of solar cell. Indium is a constitutive element of CIGS thin-film solar cells. It was thought that indium compounds were not harmful until the beginning of the 1990s because there was little information regarding the adverse health effects on humans or animals arising from exposure to indium compounds. After the mid-1990s, data became available indicating that indium compounds can be toxic to animals. In animal studies, it has been clearly demonstrated that indium compounds cause pulmonary toxicity and that the dissolution of indium compounds in the lungs is considerably slow, as shown by repeated intratracheal instillations in experimental animals. Thus, it is necessary to pay much greater attention to human exposure to indium compounds, and precautions against possible exposure to indium compounds are paramount with regard to health management.

  9. Fast and effective low-temperature freezing extraction technique to determine organotin compounds in edible vegetable oil.

    PubMed

    Liu, Yingxia; Ma, Yaqian; Wan, Yiqun; Guo, Lan; Wan, Xiaofen

    2016-06-01

    Most organotin compounds that have been widely used in food packaging materials and production process show serious toxicity effects to human health. In this study, a simple and low-cost method based on high-performance liquid chromatography with inductively coupled plasma mass spectrometry for the simultaneous determination of four organotins in edible vegetable oil samples was developed. Four organotins including dibutyltin dichloride, tributyltin chloride, diphenyltin dichloride, and triphenyltin chloride were simultaneously extracted with methanol using the low-temperature precipitation process. After being concentrated, the extracts were purified by matrix solid-phase dispersion using graphitized carbon black. The experimental parameters such as extraction solvent and clean-up material were optimized. To evaluate the accuracy of the new method, the recoveries were investigated. In addition, a liquid chromatography with tandem mass spectrometry method was also proposed for comparison. The procedures of extracting and purifying samples for the analysis were simple and easy to perform batch operations, also showed good efficiency with lower relative standard deviation. The limits of detection of the four organotins were 0.28-0.59 μg/L, and the limits of quantification of the four organotins were 0.93-1.8 μg/L, respectively. The proposed method was successfully applied to the simultaneous analysis of the four organotins in edible vegetable oil. Some analytes were detected at the level of 2.5-28.8 μg/kg. PMID:27138689

  10. Chiral separation of the clinically important compounds fucose and pipecolic acid using CE: determination of the most effective chiral selector.

    PubMed

    Hadjistasi, Christoforos A; Stavrou, Ioannis J; Stefan-Van Staden, Raluca-Ioana; Aboul-Enein, Hassan Y; Kapnissi-Christodoulou, Constantina P

    2013-09-01

    In this study, simple electrophoretic methods were developed for the chiral separation of the clinically important compounds fucose and pipecolic acid. In recent years, these analytes, and particularly their individual enantiomers, have attracted considerable attention due to their role in biological functions and disorders. The detectability and sensitivity of pipecolic acid and fucose were improved by reacting them with fluorenylmethyloxycarbonyl chloride (FMOC-Cl) and 5-amino-2-naphthalene-sulfonic acid (ANSA), respectively. The enantioseparation conditions were optimized by initially investigating the type of the chiral selector. Different chiral selectors, such as polymeric surfactants and cyclodextrins, were used and the most effective ones were determined with regard to resolution and analysis time. A 10-mM β-cyclodextrin was able to separate the enantiomers of ANSA-DL-fucose and the polymeric surfactant poly(sodium N-undecanoyl-LL-leucine-valinate) was able to separate the enantiomers of FMOC-DL-pipecolic acid, with resolution values of 3.45 and 2.78, respectively. Additional parameters, such as the concentration and the pH of the background electrolyte (BGE), the concentration of the chiral selector, and the addition of modifiers were examined in order to optimize the separations. The addition of the chiral ionic liquid D-alanine tert-butyl ester lactate into the BGE was also investigated, for the first time, in order to improve resolution of the enantiomers.

  11. Fast and effective low-temperature freezing extraction technique to determine organotin compounds in edible vegetable oil.

    PubMed

    Liu, Yingxia; Ma, Yaqian; Wan, Yiqun; Guo, Lan; Wan, Xiaofen

    2016-06-01

    Most organotin compounds that have been widely used in food packaging materials and production process show serious toxicity effects to human health. In this study, a simple and low-cost method based on high-performance liquid chromatography with inductively coupled plasma mass spectrometry for the simultaneous determination of four organotins in edible vegetable oil samples was developed. Four organotins including dibutyltin dichloride, tributyltin chloride, diphenyltin dichloride, and triphenyltin chloride were simultaneously extracted with methanol using the low-temperature precipitation process. After being concentrated, the extracts were purified by matrix solid-phase dispersion using graphitized carbon black. The experimental parameters such as extraction solvent and clean-up material were optimized. To evaluate the accuracy of the new method, the recoveries were investigated. In addition, a liquid chromatography with tandem mass spectrometry method was also proposed for comparison. The procedures of extracting and purifying samples for the analysis were simple and easy to perform batch operations, also showed good efficiency with lower relative standard deviation. The limits of detection of the four organotins were 0.28-0.59 μg/L, and the limits of quantification of the four organotins were 0.93-1.8 μg/L, respectively. The proposed method was successfully applied to the simultaneous analysis of the four organotins in edible vegetable oil. Some analytes were detected at the level of 2.5-28.8 μg/kg.

  12. Determination of the mechanism of demethylenation of (methylenedioxy)phenyl compounds by cytochrome P450 using deuterium isotope effects

    SciTech Connect

    Fukuto, J.M.; Kumagai, Y.; Cho, A.K. )

    1991-09-01

    The mechanism of demethylenation of (methylenedioxy)benzene (MDB), (methylenedioxy)amphetamine (MDA), and (methylenedioxy)methamphetamine (MDMA) by purified rabbit liver cytochrome P450IIB4 has been investigated by using deuterium isotope effects. A comparison of the magnitude and direction of the observed kinetic isotope effects indicates that the three compounds are demethylenated by different mechanisms. The different mechanisms of demethylenation have been proposed on the basis of comparisons of the observed biochemical isotope effects with the isotope effects from purely chemical systems.

  13. Bilayer Effects of Antimalarial Compounds

    PubMed Central

    Ramsey, Nicole B.; Andersen, Olaf S.

    2015-01-01

    Because of the perpetual development of resistance to current therapies for malaria, the Medicines for Malaria Venture developed the Malaria Box to facilitate the drug development process. We tested the 80 most potent compounds from the box for bilayer-mediated effects on membrane protein conformational changes (a measure of likely toxicity) in a gramicidin-based stopped flow fluorescence assay. Among the Malaria Box compounds tested, four compounds altered membrane properties (p< 0.05); MMV007384 stood out as a potent bilayer-perturbing compound that is toxic in many cell-based assays, suggesting that testing for membrane perturbation could help identify toxic compounds. In any case, MMV007384 should be approached with caution, if at all. PMID:26551613

  14. Determination of compounds responsible for tempeh aroma.

    PubMed

    Jeleń, Henryk; Majcher, Małgorzata; Ginja, Alexandra; Kuligowski, Maciej

    2013-11-01

    Tempeh is a fermented food, popular mainly in south-east Asia, but also among vegetarians worldwide. It is produced by fermenting soybean or other beans with Rhizopus strains and usually eaten deep-fried, steamed or roasted. The flavour of tempeh depends upon the fermentation time, beans used and the (eventual) frying process. Our goal was to identify compounds responsible for the unique aroma of fermented and fried soy tempeh. Gas chromatography-olfactometry (GC-O) with the aroma extract dilution analysis (AEDA) approach, was used to determine key odorants after 1 and 5 days of fermentation and subsequent frying. Comprehensive gas chromatography-mass spectrometry (GC×GC-ToF-MS) was used for their quantitation using stable isotope dilution analysis (SIDA) or standard addition (SA) methods. Odour activity values (OAV) were calculated for 19 out of 21 key odorants. Tempeh was fermented for 5 days and fried, and the main aroma compounds were found to be the following: 2-acetyl-1-pyrroline, (FD=1024, OAV 1380), 2-ethyl-3,5-dimethylpyrazine (FD=512, OAV 338), dimethyl trisulfide, (FD=512, OAV 900), methional (FD=512, OAV 930), 2-methylpropanal (FD=512, OAV 311) and (E,E)-2,4-decadienal (FD=512, OAV 455). The frying process induced the increase or appearance of the main key odorants in tempeh.

  15. Effect of the solvent and the sample preparation on the determination of triterpene compounds in two-phase olive-mill-waste samples.

    PubMed

    Fernández-Hernández, Antonia; Martinez, Antonio; Rivas, Francisco; García-Mesa, Jose A; Parra, Andres

    2015-05-01

    A simple and rapid extraction method has been employed to determine several value-added compounds, mainly triterpenes, in two-phase olive-mill-waste samples. The compounds were extracted with methanol or ethyl acetate, and the initial fresh samples were treated for classic techniques such as drying, drying and oil extraction, and drying and sifting of the olive stones. For the identification and quantitation of the compounds, an ultra performance liquid chromatography-mass spectrometry method was employed. The best results of the triterpenic compound content were achieved by extraction with methanol from the fresh sample for the oleanolic and ursolic acids, and erythrodiol and uvaol; and from the dried-extracted sample for the maslinic acid. Conversely, the best results for the linoleic acid content were reached by extraction with ethyl acetate from the dried-sifted sample. These are remarkable processes that make the solid wastes from the olive-oil industry reach a high added value. PMID:25773914

  16. THE DETERMINATION OF NON-PESTICIDAL AND PESTICIDAL ORGANOTIN COMPOUNDS IN WATER BY GAS CHROMATOGRAPHY WITH [PULSED] FLAME PHOTOMETRIC DETECTION (GS/PFPD): THE EFFECTS OF "MASS" DISCRIMINATION

    EPA Science Inventory

    Capillary gas chromatography with GC/PFPD was used in the development of analytical methodology for determining both non-pesticidal and pesticidal organotin compounds in drinking water and other aqueous matrices. The method involves aqueous ethylation of organotin analytes with ...

  17. The effect of surfactant on headspace single drop microextraction for the determination of some volatile aroma compounds in citronella grass and lemongrass leaves by gas chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid method for the determination of some volatile aromatic compounds (VACs), including citronellal, citronellol, neral, geranial, geraniol, and eugenol in citronella grass and lemongrass leaves, was developed using surfactant as a surface tension modifier while performing headspace single drop m...

  18. Determination of Solvent Effects on Keto-Enol Equilibria of 1,3-Dicarbonyl Compounds Using NMR: Revisiting a Classic Physical Chemistry Experiment

    ERIC Educational Resources Information Center

    Cook, A. Gilbert; Feltman, Paul M.

    2007-01-01

    The use of proton NMR to determine the equilibrium position of tautomeric 1,3-dicarbonyl compounds in various solvents has been a classic physical chemistry experiment. We are presenting an expansion of the excellent description of this experiment by Garland, Shoemaker, and Nibler. Often the assumption is made that the keto tautomer is always the…

  19. Determination of arsenic compounds in earthworms

    SciTech Connect

    Geiszinger, A.; Goessler, W.; Kuehnelt, D.; Kosmus, W.; Francesconi, K.

    1998-08-01

    Earthworms and soil collected from six sites in Styria, Austria, were investigated for total arsenic concentrations by ICP-MS and for arsenic compounds by HPLC-ICP-MS. Total arsenic concentrations ranged from 3.2 to 17.9 mg/kg dry weight in the worms and from 5.0 to 79.7 mg/kg dry weight in the soil samples. There was no strict correlation between the total arsenic concentrations in the worms and soil. Arsenic compounds were extracted from soil and a freeze-dried earthworm sample with a methanol/water mixture (9:1, v/v). The extracts were evaporated to dryness, redissolved in water, and chromatographed on an anion- and a cation-exchange column. Arsenic compounds were identified by comparison of the retention times with known standards. Only traces of arsenic acid could be extracted from the soil with the methanol/water (9:1, v/v) mixture. The major arsenic compounds detected in the extracts of the earthworms were arsenous acid and arsenic acid. Arsenobetaine was present as a minor constituent, and traces of dimethylarsinic acid were also detected. Two dimethylarsinoyltribosides were also identified in the extracts by co-chromatography with standard compounds. This is the first report of the presence of dimethylarsinoylribosides in a terrestrial organism. Two other minor arsenic species were present in the extract, but their retention times did not match with the retention times of the available standards.

  20. Matrix effect of sodium compounds on the determination of metal ions in aqueous solutions by underwater laser-induced breakdown spectroscopy

    DOE PAGES

    Goueguel, Christian; McIntyre, Dustin L.; Jain, Jinesh; Karamalidis, Athanasios K.; Carson, Cantwell

    2015-06-30

    A significant portion of the carbon sequestration research being performed in the United States involves the risk assessment of injecting large quantities of carbon dioxide into deep saline aquifers. Leakage of CO2 has the potential to affect the quality of groundwater supplies in case contaminants migrate through underlying conduits. New remote sensing and near-surface monitoring technologies are needed to ensure that injection, abandoned, and monitoring wells are structurally sound, and that CO2 remains within the geologic storage reservoir. In this paper, we propose underwater laser-induced breakdown spectroscopy (underwater LIBS) as an analytical method for monitoring naturally occurring elements that canmore » act as tracers to detect a CO2 leak from storage sites. Laboratory-scale experiments were conducted to measure Sr2+, Ca2+, K+, and Li+ in bulk solutions to ascertain the analytical performance of underwater LIBS. We compared the effect of NaCl, Na2CO3, and Na2SO4 on the analytes calibration curves to determine underwater LIBS’ ability to analyze samples of sodium compounds. In all cases, the calibration curves showed a good linearity within 2 orders of magnitude. The limit of detections (LODs) obtained for K+ (30±1 ppb) and Li+ (60±2 ppb) were in ppb range, while higher LODs were observed for Ca2+ (0.94±0.14 ppm) and Sr2+ (2.89±0.11 ppm). Evaluation of the calibration curves for the analytes in mixed solutions showed dependence of the lines’ intensity with the sodium compounds. The intensities increased respectively in the presence of dissolved NaCl and Na2SO4, whereas the intensities slightly decreased in the presence of Na2CO3. Lastly, the capabilities of underwater LIBS to detect certain elements in the ppb or in the low ppm range make it particularly appealing for in situ monitoring of a CO2 leak.« less

  1. Highly sensitive flow-injection chemiluminescence determination of pyrogallol compounds

    NASA Astrophysics Data System (ADS)

    Kanwal, Shamsa; Fu, Xiaohong; Su, Xingguang

    2009-12-01

    A highly sensitive flow-injection chemiluminescent method for the direct determination of pyrogallol compounds has been developed. Proposed method is based on the enhanced effect of pyrogallol compounds on the chemiluminescence signals of KMnO 4-H 2O 2 system in slightly alkaline medium. Three important pyrogallol compounds, pyrogallic acid, gallic acid and tannic acid, have been detected by this method, and the possible mechanism of the CL reaction is also discussed. The proposed method is simple, convenient, rapid (60 samples h -1), and sensitive, has a linear range of 8 × 10 -10 mol L -1 to 1 × 10 -5 mol L -1, for pyrogallic acid, with a detection limit of 6 × 10 -11 mol L -1, 4 × 10 -8 mol L -1 to 5 × 10 -3 mol L -1 for gallic acid with a detection limit of 9 × 10 -10 mol L -1, and 8 × 10 -8 mol L -1 to 5 × 10 -2 mol L -1 for tannic acid, with a detection limit of 2 × 10 -9 mol L -1, respectively. The relative standard deviation (RSD, n = 15) was 0.8, 1.1 and 1.3% for 5 × 10 -6 mol L -1 pyrogallic acid, gallic acid and tannic acid, respectively. The proposed method was successfully applied to the determination of pyrogallol compounds in tea and coffee samples.

  2. Ozonation of sludge-press liquors: Determination of carbonyl compounds by the PFBOA method and the effect on the chemical oxygen demand

    SciTech Connect

    Boyle, L.L.; McCullough, N.H.; Poppelen, P. van

    1996-12-31

    The European Community Urban Waste Water Treatment Directive, May 1991, requires water service companies to provide sufficient wastewater treatment to meet a new limit set for the Chemical Oxygen Demand (COD) in final effluent and new legislation has placed limits on the levels of COD that can be discharged from wastewater treatment works using secondary treatment processes. The current permitted upper level for COD in the final effluent is 125 mg per litre. Ozone is a strong oxidant and disinfectant and in contrast to chlorine, does not produce chlorinated by-products from its reaction with natural organic matter in water. In spite of the successful use of ozone for the treatment of potable waters since the early part of the century very few studies have been undertaken into possible chemical by-products which might arise from ozonation. Since the amount of ozone applied is always lower than that required to oxidize all the organic matter to carbon dioxide and water, a number of semi-oxidation products such as aromatic, phenolic and aliphatic carboxylic acids, aldehydes and ketones can be expected to be formed. The ozonation of sludge-press liquors and the resultant effect on COD was investigated. The concentration of carbonyl compounds was analyzed using O-(pentafluorobenzyl) hydroxylamine (PFBOA) as a derivatising agent in Gas Chromatographic (GC) determination.

  3. Matrix effect of sodium compounds on the determination of metal ions in aqueous solutions by underwater laser-induced breakdown spectroscopy

    SciTech Connect

    Goueguel, Christian; McIntyre, Dustin L.; Jain, Jinesh; Karamalidis, Athanasios K.; Carson, Cantwell

    2015-06-30

    A significant portion of the carbon sequestration research being performed in the United States involves the risk assessment of injecting large quantities of carbon dioxide into deep saline aquifers. Leakage of CO2 has the potential to affect the quality of groundwater supplies in case contaminants migrate through underlying conduits. New remote sensing and near-surface monitoring technologies are needed to ensure that injection, abandoned, and monitoring wells are structurally sound, and that CO2 remains within the geologic storage reservoir. In this paper, we propose underwater laser-induced breakdown spectroscopy (underwater LIBS) as an analytical method for monitoring naturally occurring elements that can act as tracers to detect a CO2 leak from storage sites. Laboratory-scale experiments were conducted to measure Sr2+, Ca2+, K+, and Li+ in bulk solutions to ascertain the analytical performance of underwater LIBS. We compared the effect of NaCl, Na2CO3, and Na2SO4 on the analytes calibration curves to determine underwater LIBS’ ability to analyze samples of sodium compounds. In all cases, the calibration curves showed a good linearity within 2 orders of magnitude. The limit of detections (LODs) obtained for K+ (30±1 ppb) and Li+ (60±2 ppb) were in ppb range, while higher LODs were observed for Ca2+ (0.94±0.14 ppm) and Sr2+ (2.89±0.11 ppm). Evaluation of the calibration curves for the analytes in mixed solutions showed dependence of the lines’ intensity with the sodium compounds. The intensities increased respectively in the presence of dissolved NaCl and Na2SO4, whereas the intensities slightly decreased in the presence of Na2CO3. Lastly, the capabilities of underwater LIBS to detect certain elements in the ppb or in the low ppm range make it

  4. Matrix effect of sodium compounds on the determination of metal ions in aqueous solutions by underwater laser-induced breakdown spectroscopy.

    PubMed

    Goueguel, Christian; McIntyre, Dustin L; Jain, Jinesh; Karamalidis, Athanasios K; Carson, Cantwell

    2015-07-01

    A significant portion of the carbon sequestration research being performed in the United States involves the risk assessment of injecting large quantities of carbon dioxide into deep saline aquifers. Leakage of CO2 has the potential to affect the quality of groundwater supplies in case contaminants migrate through underlying conduits. New remote sensing and near-surface monitoring technologies are needed to ensure that injection, abandoned, and monitoring wells are structurally sound, and that CO2 remains within the geologic storage reservoir. In this paper, we propose underwater laser-induced breakdown spectroscopy (underwater LIBS) as an analytical method for monitoring naturally occurring elements that can act as tracers to detect a CO2 leak from storage sites. Laboratory-scale experiments were conducted to measure Sr2+, Ca2+, K(+), and Li(+) in bulk solutions to ascertain the analytical performance of underwater LIBS. We compared the effect of NaCl, Na2CO3, and Na2SO4 on the analytes calibration curves to determine underwater LIBS' ability to analyze samples of sodium compounds. In all cases, the calibration curves showed a good linearity within 2 orders of magnitude. The limit of detections (LODs) obtained for K(+) (30±1  ppb) and Li(+) (60±2  ppb) were in ppb range, while higher LODs were observed for Ca(2+) (0.94±0.14  ppm) and Sr(2+) (2.89±0.11  ppm). Evaluation of the calibration curves for the analytes in mixed solutions showed dependence of the lines' intensity with the sodium compounds. The intensities increased respectively in the presence of dissolved NaCl and Na2SO4, whereas the intensities slightly decreased in the presence of Na2CO3. Finally, the capabilities of underwater LIBS to detect certain elements in the ppb or in the low ppm range make it particularly appealing for in situ monitoring of a CO2 leak.

  5. Methods of Selenium Supplementation: Bioavailability and Determination of Selenium Compounds.

    PubMed

    Bodnar, Malgorzata; Szczyglowska, Marzena; Konieczka, Piotr; Namiesnik, Jacek

    2016-01-01

    Selenium, a "dual-surface" element, maintains a very thin line between a level of necessity and harmfulness. Because of this, a deficiency or excess of this element in an organism is dangerous and causes health-related problems, both physically and mentally. The main source of selenium is a balanced diet, with a proper selection of meat and plant products. Meanwhile, the proper assimilation of selenium into these products depends on their bioavailability, bioaccessibility, and/or bioactivity of a given selenium compound. From the time when it was discovered that selenium and its compounds have a significant influence on metabolic processes and in many countries throughout the world, a low quantity of selenium was found in different parts of the environment, pressure was put upon an effective and fast method of supplementing the environment with the help of selenium. This work describes supplementation methods applied with the use of selenium, as well as new ideas for increasing the level of this element in various organisms. Based on the fact that selenium appears in the environment at trace levels, the determination of total amount of selenium or selenium speciation in a given sample demands the selection of appropriate measurement methods. These methods are most often comprised of a sample preparation technique and/or a separation technique as well as a detection system. The work presents information on the subject of analytical methods used for determining selenium and its compounds as well as examples in literature of their application.

  6. Determination of Perfluorinated Compounds in the Upper Mississippi River Basin

    EPA Science Inventory

    Despite ongoing efforts to develop robust analytical methods for the determination of perfluorinated compounds (PFCs) such as perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) in surface water, comparatively little has been published on method performance, and the...

  7. Determining the Degree of Promiscuity of Extensively Assayed Compounds

    PubMed Central

    Jasial, Swarit; Hu, Ye; Bajorath, Jürgen

    2016-01-01

    In the context of polypharmacology, an emerging concept in drug discovery, promiscuity is rationalized as the ability of compounds to specifically interact with multiple targets. Promiscuity of drugs and bioactive compounds has thus far been analyzed computationally on the basis of activity annotations, without taking assay frequencies or inactivity records into account. Most recent estimates have indicated that bioactive compounds interact on average with only one to two targets, whereas drugs interact with six or more. In this study, we have further extended promiscuity analysis by identifying the most extensively assayed public domain compounds and systematically determining their promiscuity. These compounds were tested in hundreds of assays against hundreds of targets. In our analysis, assay promiscuity was distinguished from target promiscuity and separately analyzed for primary and confirmatory assays. Differences between the degree of assay and target promiscuity were surprisingly small and average and median degrees of target promiscuity of 2.6 to 3.4 and 2.0 were determined, respectively. Thus, target promiscuity remained at a low level even for most extensively tested active compounds. These findings provide further evidence that bioactive compounds are less promiscuous than drugs and have implications for pharmaceutical research. In addition to a possible explanation that drugs are more extensively tested for additional targets, the results would also support a “promiscuity enrichment model” according to which promiscuous compounds might be preferentially selected for therapeutic efficacy during clinical evaluation to ultimately become drugs. PMID:27082988

  8. Synchrotron radiation-based experimental determination of the optimal energy for cell radiotoxicity enhancement following photoelectric effect on stable iodinated compounds.

    PubMed

    Corde, S; Joubert, A; Adam, J F; Charvet, A M; Le Bas, J F; Estève, F; Elleaume, H; Balosso, J

    2004-08-01

    This study was designed to experimentally evaluate the optimal X-ray energy for increasing the radiation energy absorbed in tumours loaded with iodinated compounds, using the photoelectric effect. SQ20B human cells were irradiated with synchrotron monochromatic beam tuned at 32.8, 33.5, 50 and 70 keV. Two cell treatments were compared to the control: cells suspended in 10 mg ml(-1) of iodine radiological contrast agent or cells pre-exposed with 10 microM of iodo-desoxyuridine (IUdR) for 48 h. Our radiobiological end point was clonogenic cell survival. Cells irradiated with both iodine compounds exhibited a radiation sensitisation enhancement. Moreover, it was energy dependent, with a maximum at 50 keV. At this energy, the sensitisation calculated at 10% survival was equal to 2.03 for cells suspended in iodinated contrast agent and 2.60 for IUdR. Cells pretreated with IUdR had higher sensitisation factors over the energy range than for those suspended in iodine contrast agent. Also, their survival curves presented no shoulder, suggesting complex lethal damages from Auger electrons. Our results confirm the existence of the 50 keV energy optimum for a binary therapeutic irradiation based on the presence of stable iodine in tumours and an external irradiation. Monochromatic synchrotron radiotherapy concept is hence proposed for increasing the differential effect between healthy and cancerous tissue irradiation.

  9. Determination of hydroxylated thiophenic compounds in a coal liquid

    SciTech Connect

    Nishioka, M.; Lee, M.L.; Kudo, H.; Muchiri, D.R.; Baldwin, L.J.; Pakray, S.; Stuart, J.G.; Castle, R.N.

    1985-06-01

    Hydroxylated thiophenic compounds in a coal liquid were determined by capillary column gas chromatography and gas chromatography/mass spectrometry. Capillary column gas chromatography with two new selective stationary phases, a biphenyl polysiloxane and a smectic liquid crystalline poly-siloxane, were used. Several compounds were positively identified by comparison of their retention times with those of newly synthesized standard compounds. Sulfur-selective flame photometric detection and mass spectrometry were used to verify compound identifications. Two groupings of hydroxylated thiophenic compounds were observed in this sample. The first group is composed of hydroxybenzo-thiophenes and (hydroxyphenyl)thiophenes, while the second group contains hydroxydibenzothiophenes and (hydroxyphenyl)benzothiophenes. 22 references, 2 figures, 1 table.

  10. Determination of organic nitro compounds using HPLC-UV-PAED

    NASA Astrophysics Data System (ADS)

    Marple, Ronita L.; LaCourse, William R.

    2004-12-01

    High-performance liquid chromatography with ultra violet and photo-assisted electrochemical detection (HPLC-UV-PAED) has been applied to the sensitive and selective determination of organic nitro compounds. The system was first developed for the determination of nitro explosives, and PAED has shown superior sensitivity over UV detection for these compounds (i.e., <1 part-per-trillion for HMX). The system also shows enhanced selectivity over the traditional UV method in that two detectors can be used for improved analyte identification. Also, having two detectors permits chemometric resolution of overlapping peaks, and this is not addressed in the UV method. Because this method is applicable to a wide range of nitro explosives, it was predicted that PAED would show the same sensitivity and selectivity toward other types of nitro compounds. Since its development, the system's use has been expanded to include the determination of nitro-containing pharmaceuticals and glycosylated nitro compounds in biological matrices. Model compounds were chosen, specifically nitroglycerin and related compounds and nitrophenyl-glucoside, to represent these classes. PAED showed superior detection limits over low wavelength UV detection for nitroglycerin (PAED = 0.3ppb, UV at 220nm = 48ppb), demonstrating PAED"s applicability to determining nitro-pharmaceuticals. Conversely, UV detection at 220nm proved to be more sensitive than PAED for nitrophenyl-glucoside (UV at 220 = 0.6ppb, PAED = 3.6ppb). However, when nitrophenyl-glucoside was spiked into urine, PAED determination resulted in 99+0.3% recovery, while UV at 220nm resulted in 116+0.2% recovery, suggesting that UV determination may suffer from matrix interference.

  11. [Determination of organotin compounds in polyvinyl chloride toys].

    PubMed

    Ohno, Hiroyuki; Suzuki, Masako; Aoyama, Taiki; Mitani, Kazunori

    2003-08-01

    Organotin compounds in polyvinyl chloride toys were determined by GC/MS after ethyl derivatization with sodium tetraethylborate. The samples were 12 balls, 12 soft toys, 10 food toys and 13 face masks for children. Monooctyltin, dioctyltin and trioctyltin compounds were found in all face masks at the levels of 74.8-917 micrograms/g. 474-3,960 micrograms/g and 1.0-213 micrograms/g, respectively. They also were detected in 6 balls, 4 soft toys and 1 food toy. Monomethyltin and dimethyltin compounds were found in 8 face masks at the levels of 40.9-227 micrograms/g and 222-1,450 micrograms/g, respectively. Monobutyltin and dibutyltin (DBT) compounds were found in 1 ball, 3 food toys and 5 face masks. In particular, 1 ball and 4 face masks contained toxic DBT at the levels of 527-999 micrograms/g.

  12. [Spectrophotometric determination of aromatic amino compounds with J-acid].

    PubMed

    Yin, Xiao-hang; Shi, Wen-jian; Shen, Xin; Ma, Jun-tao; Li, Liang

    2015-01-01

    The problems such as chromogenic reaction selectivity, reaction rate, sensitivity and water-solubility of azo compounds were considered. The molecular structures of coupling components were theoretically designed and screened in the present research The reaction conditions and methods of chromogenic reaction were investigated. J-Acid (2-amino-5-naphthol-7-sulfonic acid) as a coupling reagent to determine aromatic amino compounds was established. In the presence of potassium bromide, at room temperature, nitrite reacted with aromatic amino compounds in the medium of thin hydrochloric acid. Then diazonium salt reacted with J-Acid in the aqueous solution of sodium carbonate, forming coloured azo dye, which had a maximum adsorption at 480 nm. The molar adsorption coeffcients of aniline, 4-aminobenzene sulfonic acid and 1-naphthylamine were 3. 95 X 10(4), 3. 24 X 10(4) and 3. 91 X 10(4) L . mol-1 . cm-1 , respectively. Experimental results showed that common coexisting ions on the surface water did not affect the results of determination. J-Acid of spectrophotometry was used to determine the samples of Shanghai Fu Xing Dao canal. Meanwhile, recovery experiments by standard addition method were done. Experiment results showed that the recoveries of aniline were in the range of 98. 5%-102. 1%, and RSD was 2. 08%. J-Acid is a common organic reagent. It is soluble in water and low volatile, and its toxicity is much lower than N-ethylenediamine. spectrophotometric determination of aromatic amino compounds by J-Acid has the advantage of high sensitivity, good selectivity, simple rapid operation and accurate results, and thus it can be used for the determination of trace aromatic amino compounds in the environmental water.

  13. Determination of free and bound phenolic compounds in buckwheat spaghetti by RP-HPLC-ESI-TOF-MS: effect of thermal processing from farm to fork.

    PubMed

    Verardo, Vito; Arraez-Roman, David; Segura-Carretero, Antonio; Marconi, Emanuele; Fernandez-Gutierrez, Alberto; Caboni, Maria Fiorenza

    2011-07-27

    Nowadays there is considerable interest in the consumption of alternative crops as potential recipes for gluten-free products production. Therefore, the use of buckwheat for the production of gluten-free pasta has been investigated in the present study. RP-HPLC-ESI-TOF-MS has been applied for the separation and characterization of free and bound phenolic compounds in buckwheat flour and buckwheat spaghetti. Thus, 32 free and 24 bound phenolic compounds in buckwheat flour and spaghetti have been characterized and quantified. To the authors' knowledge, protochatechuic-4-O-glucoside acid and procyanidin A have been detected in buckwheat for the first time. The results have demonstrated a decrease of total free phenolic compounds from farm to fork (from flour to cooked spaghetti) of about 74.5%, with a range between 55.3 and 100%, for individual compounds. The decrease in bound phenols was 80.9%, with a range between 46.2 and 100%. The spaghetti-making process and the cooking caused losses of 46.1 and 49.4% of total phenolic compounds, respectively. Of the total phenolic compounds present in dried spaghetti, 11.6% were dissolved in water after cooking.

  14. Determination of fluorine in organic compounds: Microcombustion method

    USGS Publications Warehouse

    Clark, H.S.

    1951-01-01

    A reliable and widely applicable means of determining fluorine in organic compounds has long been needed. Increased interest in this field of research in recent years has intensified the need. Fluorine in organic combinations may be determined by combustion at 900?? C. in a quartz tube with a platinum catalyst, followed by an acid-base titration of the combustion products. Certain necessary precautions and known limitations are discussed in some detail. Milligram samples suffice, and the accuracy of the method is about that usually associated with the other halogen determinations. Use of this method has facilitated the work upon organic fluorine compounds in this laboratory and it should prove to be equally valuable to others.

  15. Sensitive, Rapid, and Specific Bioassay for the Determination of Antilipogenic Compounds

    PubMed Central

    Ulitzur, S.; Goldberg, I.

    1977-01-01

    A sensitive and rapid bioassay for the determination of the antilipogenic compounds cerulenin and CM-55 is described. The bioassay is based on the inhibitory effect of cerulenin and CM-55 on the in vivo luminescence of an aldehyde-requiring mutant of the marine bacterium Beneckea harveyi. A total quantity as low as 0.1 μg of cerulenin can be determined within 15 min with an error of ±2%. The bioassay, as presented, is specific for compounds that are known to inhibit fatty acid biosynthesis and, as such, it might be used as a general screening method for the detection of antilipogenic compounds. PMID:303076

  16. Excitonic effects in oxyhalide scintillating host compounds

    SciTech Connect

    Shwetha, G.; Kanchana, V.; Valsakumar, M. C.

    2014-10-07

    Ab-initio calculations based on density functional theory have been performed to study the electronic, optical, mechanical, and vibrational properties of scintillator host compounds YOX (X = F, Cl, Br, and I). Semiempirical dispersion correction schemes are used to find the effect of van der Waals forces on these layered compounds and we found this effect to be negligible except for YOBr. Calculations of phonons and elastic constants showed that all the compounds studied here are both dynamically and mechanically stable. YOF and YOI are found to be indirect band gap insulators while YOCl and YOBr are direct band gap insulators. The band gap is found to decrease as we move from fluorine to iodine, while the calculated refractive index shows the opposite trend. As the band gap decreases on going down the periodic table from YOF to YOI, the luminescence increases. The excitonic binding energy calculated, within the effective mass approximation, is found to be more for YOF than the remaining compounds, suggesting that the excitonic effect to be more in YOF than the other compounds. The optical properties are calculated within the Time-Dependent Density Functional Theory (TDDFT) and compared with results obtained within the random phase approximation. The TDDFT calculations, using the newly developed bootstrap exchange-correlation kernel, showed significant excitonic effects in all the compounds studied here.

  17. A simple method to determine mineralization of (14) C-labeled compounds in soil.

    PubMed

    Myung, Kyung; Madary, Michael W; Satchivi, Norbert M

    2014-06-01

    Degradation of organic compounds in soil is often determined by measuring the decrease of the parent compound and analyzing the occurrence of its metabolites. However, determining carbon species as end products of parent compound dissipation requires using labeled materials that allow more accurate determination of the environmental fate of the compound of interest. The current conventional closed system widely used to monitor degradation of (14) C-labeled compounds in soil is complex and expensive and requires a specialized apparatus and facility. In the present study, the authors describe a simple system that facilitates measurement of mineralization of (14) C-labeled compounds applied to soil samples. In the system, soda lime pellets to trap mineralized (14) C-carbon species, including carbon dioxide, were placed in a cup, which was then inserted above the treated soil sample in a tube. Mineralization of [(14) C]2,4-D applied to soil samples in the simple system was compared with that in the conventional system. The simple system provided an equivalent detection of (14) C-carbon species mineralized from the parent compound. The results demonstrate that this cost- and space-effective simple system is suitable for examining degradation and mineralization of (14) C-labeled compounds in soil and could potentially be used to investigate their mineralization in other biological matrices.

  18. Toxic effects of chromium and its compounds.

    PubMed

    Baruthio, F

    1992-01-01

    Chromium was discovered in 1797 by Vauquelin. Numerous industrial applications raised chromium to a very important economic element. At the same time, with the development of its uses, the adverse effects of chromium compounds in human health were being defined. Trivalent chromium is an essential trace element in humans and in animals. Chromium as pure metal has no adverse effect. Little toxic effect is attributed to trivalent chromium when present in very large quantities. Both acute and chronic toxicity of chromium are mainly caused by hexavalent compounds. The most important toxic effects, after contact, inhalation, or ingestion of hexavalent chromium compounds are the following: dermatitis, allergic and eczematous skin reactions, skin and mucous membrane ulcerations, perforation of the nasal septum, allergic asthmatic reactions, bronchial carcinomas, gastro-enteritis, hepatocellular deficiency, and renal oligo anuric deficiency. Prevention of occupational risks, biological monitoring of workers, and treatment of poisoning are also reported.

  19. Exchange bias effect in alloys and compounds.

    PubMed

    Giri, S; Patra, M; Majumdar, S

    2011-02-23

    The phenomenology of exchange bias effects observed in structurally single-phase alloys and compounds but composed of a variety of coexisting magnetic phases such as ferromagnetic, antiferromagnetic, ferrimagnetic, spin-glass, cluster-glass and disordered magnetic states are reviewed. The investigations on exchange bias effects are discussed in diverse types of alloys and compounds where qualitative and quantitative aspects of magnetism are focused based on macroscopic experimental tools such as magnetization and magnetoresistance measurements. Here, we focus on improvement of fundamental issues of the exchange bias effects rather than on their technological importance.

  20. Chemical state determination of molecular gallium compounds using XPS.

    PubMed

    Bourque, Jeremy L; Biesinger, Mark C; Baines, Kim M

    2016-05-01

    A series of molecular gallium compounds were analyzed using X-ray photoelectron spectroscopy (XPS). Specifically, the Ga 2p3/2 and Ga 3d5/2 photoelectron binding energies and the Ga L3M45M45 Auger electron kinetic energies of compounds with gallium in a range of assigned oxidation numbers and with different stabilizing ligands were measured. Auger parameters were calculated and used to generate multiple chemical speciation (or Wagner) plots that were subsequently used to characterize the novel gallium-cryptand[2.2.2] complexes that possess ambiguous oxidation numbers for gallium. The results presented demonstrate the ability of widely accessible XPS instruments to experimentally determine the chemical state of gallium centers and, as a consequence, provide deeper insights into reactivity compared to assigned oxidation and valence numbers.

  1. Botanical Compounds: Effects on Major Eye Diseases

    PubMed Central

    Huynh, Tuan-Phat; Mann, Shivani N.; Mandal, Nawajes A.

    2013-01-01

    Botanical compounds have been widely used throughout history as cures for various diseases and ailments. Many of these compounds exhibit strong antioxidative, anti-inflammatory, and antiapoptotic properties. These are also common damaging mechanisms apparent in several ocular diseases, including age-related macular degeneration (AMD), glaucoma, diabetic retinopathy, cataract, and retinitis pigmentosa. In recent years, there have been many epidemiological and clinical studies that have demonstrated the beneficial effects of plant-derived compounds, such as curcumin, lutein and zeaxanthin, danshen, ginseng, and many more, on these ocular pathologies. Studies in cell cultures and animal models showed promising results for their uses in eye diseases. While there are many apparent significant correlations, further investigation is needed to uncover the mechanistic pathways of these botanical compounds in order to reach widespread pharmaceutical use and provide noninvasive alternatives for prevention and treatments of the major eye diseases. PMID:23843879

  2. The Negative Effects of Volatile Sulphur Compounds.

    PubMed

    Milella, Lisa

    2015-01-01

    Oral malodor has been studied extensively in humans but not necessarily to the same degree in our veterinary patients where malodor constitutes a significant problem. Breath malodor may originate from the mouth, or from an extra oral source, originating from other organ systems such as gastrointestinal, respiratory, or even systemic disease. Oral malodor is a result of microbial metabolism of exogenous and endogenous proteinaceous substrates leading to the production of compounds such as indole, skatole, tyramine, cadaverine, puterescine, mercaptans, and sulphides. Volatile sulphur compounds have been shown to be the main cause of oral malodor. Although most clients perceive oral malodor to be primarily a cosmetic problem, there is an increasing volume of evidence in human dental literature demonstrating that volatile sulphur compounds produced by bacteria, even at low concentrations, are toxic to tissues and play a role in the pathogenesis of periodontitis. This article reviews the current available literature in human dentistry looking at these negative effects. No veterinary studies have been conducted looking at the negative effects of volatile sulphur compounds specifically, but as this article highlights, we should be aware of the potential negative effects of volatile sulphur compounds and consider this an area of future research. PMID:26415386

  3. Methods for the determination of organic compounds in drinking water

    SciTech Connect

    Not Available

    1988-12-01

    Thirteen analytical methods for the identification and measurement of organic compounds in drinking water are described in detail. Six of the methods are for volatile organic compounds (VOCs) and certain disinfection by-products. These methods were cited in the Federal Register of July 8, 1987, under the National Primary Drinking Water Regulations. The other seven methods are designed for the determination of a variety of synthetic organic compounds and pesticides, and these methods were cited in proposed drinking-water regulations in the Federal Register of May 22, 1989. Five of the methods utilize the inert gas purge-and-trap extraction procedure for VOCs, six methods employ a classical liquid-liquid extraction, one method uses a new liquid-solid extraction technique, and one method is for direct aqueous analysis. Of the 13 methods, 12 use either packed or capillary gas-chromatography column separations followed by detection with mass spectrometry or a selective gas-chromatography detector. One method is based on a high-performance liquid-chromatography separation.

  4. Determination of total phenolic compounds in compost by infrared spectroscopy.

    PubMed

    Cascant, M M; Sisouane, M; Tahiri, S; Krati, M El; Cervera, M L; Garrigues, S; de la Guardia, M

    2016-06-01

    Middle and near infrared (MIR and NIR) were applied to determine the total phenolic compounds (TPC) content in compost samples based on models built by using partial least squares (PLS) regression. The multiplicative scatter correction, standard normal variate and first derivative were employed as spectra pretreatment, and the number of latent variable were optimized by leave-one-out cross-validation. The performance of PLS-ATR-MIR and PLS-DR-NIR models was evaluated according to root mean square error of cross validation and prediction (RMSECV and RMSEP), the coefficient of determination for prediction (Rpred(2)) and residual predictive deviation (RPD) being obtained for this latter values of 5.83 and 8.26 for MIR and NIR, respectively. PMID:27130128

  5. Comparative angioprotective effects of magnesium compounds.

    PubMed

    Kharitonova, Maria; Iezhitsa, Igor; Zheltova, Anastasia; Ozerov, Alexander; Spasov, Alexander; Skalny, Anatoly

    2015-01-01

    Magnesium (Mg) deficiency is implicated in the development of numerous disorders of the cardiovascular system. Moreover, the data regarding the efficacy of different magnesium compounds in the correction of impaired functions due to low magnesium intake are often fragmentary and inconsistent. The aim of this study was to compare the effects of the most bioavailable Mg compounds (Mg l-aspartate, Mg N-acetyltaurate, Mg chloride, Mg sulphate and Mg oxybutyrate) on systemic inflammation and endothelial dysfunction in rats fed a low Mg diet for 74 days. A low Mg diet decreased the Mg concentration in the plasma and erythrocytes, which was accompanied by a reduced concentration of eNOs and increased levels of endothelin-1 level in the serum and impaired endothelium-dependent vasodilatation. These effects increased the concentration of proinflammatory molecules, such as VCAM-1, TNF-α, IL-6 and CRP, indicating the development of systemic inflammation and endothelial dysfunction. The increased total NO level, which estimated from the sum of the nitrate and nitrite concentrations in the serum, may also be considered to be a proinflammatory marker. Two weeks of Mg supplementation partially or fully normalised the ability of the vascular wall to effect adequate endothelium-dependent vasodilatation and reversed the levels of most endothelial dysfunction and inflammatory markers (except CRP) to the mean values of the control group. Mg sulphate had the smallest effect on the endothelin-1, TNF-α and VCAM-1 levels. Mg N-acetyltaurate was significantly more effective in restoring the level of eNOS compared to all other studied compounds, except for Mg oxybutyrate. Taken together, the present findings demonstrate that all Mg compounds equally alleviate endothelial dysfunction and inflammation caused by Mg deficiency. Mg sulphate tended to be the least effective compound.

  6. Antiviral effect of cationic compounds on bacteriophages

    PubMed Central

    Ly-Chatain, Mai H.; Moussaoui, Saliha; Vera, Annabelle; Rigobello, Véronique; Demarigny, Yann

    2013-01-01

    The antiviral activity of several cationic compounds – cetyltrimethylammonium bromide (CTAB), chitosan, nisin, and lysozyme – was investigated on the bacteriophage c2 (DNA head and non-contractile tail) infecting Lactococcus strains and the bacteriophage MS2 (F-specific RNA) infecting E. coli. Firstly, these activities were evaluated in a phosphate buffer pH 7 – 10 mM. The CTAB had a virucidal effect on the Lactococcus bacteriophages, but not on the MS2. After 1 min of contact with 0.125 mM CTAB, the c2 population was reduced from 6 to 1.5 log(pfu)/mL and completely deactivated at 1 mM. On the contrary, chitosan inhibited the MS2 more than it did the bacteriophages c2. No antiviral effect was observed for the nisin or the lysozyme on bacteriophages after 1 min of treatment. A 1 and 2.5 log reduction was respectively observed for nisin and lysozyme when the treatment time increased (5 or 10 min). These results showed that the antiviral effect depended both on the virus and structure of the antimicrobial compounds. The antiviral activity of these compounds was also evaluated in different physico-chemical conditions and in complex matrices. The antiviral activity of CTAB was impaired in acid pH and with an increase of the ionic strength. These results might be explained by the electrostatic interactions between cationic compounds and negatively charged particles such as bacteriophages or other compounds in a matrix. Milk proved to be protective suggesting the components of food could interfere with antimicrobial compounds. PMID:23487495

  7. Determining the effects of a mixture of an endocrine disrupting compound, 17α-ethinylestradiol, and ammonia on fathead minnow (Pimephales promelas) reproduction.

    PubMed

    Armstrong, Brandon M; Lazorchak, James M; Murphy, Cheryl A; Haring, Herman J; Jensen, Kathleen M; Smith, Mark E

    2015-02-01

    Aquatic organisms are exposed to a multitude of contaminants and to fully understand the impact of multiple stressors on fish populations, we must first understand the mechanism of action for each toxicant and how the combined effects manifest at the level of the individual. 17α-ethinylestradiol (EE2) has been known to cause adverse reproductive effects including reduced fecundity and fertility, intersex and skewed sex ratios in fish by mimicking naturally produced estrogen at low concentrations. Ammonia can cause adverse reproductive and mortality effects in individual fish through effects or damage to the central nervous system. Both EE2 and ammonia are found in most municipal effluents in various concentrations. A flow-through diluter system was used to test the individual effects of these two contaminants at their respective no observable adverse effect concentration (NOAEC) as well as their combined effects on fathead minnow, (Pimephales promelas) reproduction in a mixture exposure. While neither contaminant nor their mixture altered reproduction in terms of fecundity, their mixture resulted in significant fathead minnow mortality during a 21 d exposure. This study demonstrated the need to consider mixture effects when assessing risk for toxicity testing with multiple stressors. PMID:25014901

  8. Determination of cyanogenic compounds in edible plants by ion chromatography.

    PubMed

    Cho, Hye-Jeon; Do, Byung-Kyung; Shim, Soon-Mi; Kwon, Hoonjeong; Lee, Dong-Ha; Nah, Ahn-Hee; Choi, Youn-Ju; Lee, Sook-Yeon

    2013-06-01

    Cyanogenic glycosides are HCN-producing phytotoxins; HCN is a powerful and a rapidly acting poison. It is not difficult to find plants containing these compounds in the food supply and/or in medicinal herb collections. The objective of this study was to investigate the distribution of total cyanide in nine genera (Dolichos, Ginkgo, Hordeum, Linum, Phaseolus, Prunus, Phyllostachys, Phytolacca, and Portulaca) of edible plants and the effect of the processing on cyanide concentration. Total cyanide content was measured by ion chromatography following acid hydrolysis and distillation. Kernels of Prunus genus are used medicinally, but they possess the highest level of total cyanide of up to 2259.81 CN(-)/g dry weight. Trace amounts of cyanogenic compounds were detected in foodstuffs such as mungbeans and bamboo shoots. Currently, except for the WHO guideline for cassava, there is no global standard for the allowed amount of cyanogenic compounds in foodstuffs. However, our data emphasize the need for the guidelines if plants containing cyanogenic glycosidesare to be developed as dietary supplements.

  9. Determination of Cyanogenic Compounds in Edible Plants by Ion Chromatography

    PubMed Central

    Cho, Hye-Jeon; Do, Byung-Kyung; Shim, Soon-Mi; Lee, Dong-Ha; Nah, Ahn-Hee; Choi, Youn-Ju; Lee, Sook-Yeon

    2013-01-01

    Cyanogenic glycosides are HCN-producing phytotoxins; HCN is a powerful and a rapidly acting poison. It is not difficult to find plants containing these compounds in the food supply and/or in medicinal herb collections. The objective of this study was to investigate the distribution of total cyanide in nine genera (Dolichos, Ginkgo, Hordeum, Linum, Phaseolus, Prunus, Phyllostachys, Phytolacca, and Portulaca) of edible plants and the effect of the processing on cyanide concentration. Total cyanide content was measured by ion chromatography following acid hydrolysis and distillation. Kernels of Prunus genus are used medicinally, but they possess the highest level of total cyanide of up to 2259.81 CN−/g dry weight. Trace amounts of cyanogenic compounds were detected in foodstuffs such as mungbeans and bamboo shoots. Currently, except for the WHO guideline for cassava, there is no global standard for the allowed amount of cyanogenic compounds in foodstuffs. However, our data emphasize the need for the guidelines if plants containing cyanogenic glycosidesare to be developed as dietary supplements. PMID:24278641

  10. DNA nanostructures based biosensor for the determination of aromatic compounds.

    PubMed

    Gayathri, S Baby; Kamaraj, P; Arthanareeswari, M; Devikala, S

    2015-10-15

    Graphite electrode was modified using multi-walled carbon nanotubes (MWCNT), chitosan (CS), glutaraldehyde (GTA) and DNA nanostructures (nsDNA). DNA nanostructures of 50 nm in size were produced from single DNA template sequence using a simple two step procedure and were confirmed using TEM and AFM analysis. The modified electrode was applied to the electrochemical detection of aromatic compounds using EIS. The modified electrode was characterized using differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). For comparison, electrochemical results derived from single stranded (50 bp length) and double stranded (50 bp length) DNA based biosensors were used. The results indicate that the modified electrode prior to nsDNA immobilization provides a viable platform that effectively promotes electron transfer between nsDNA and the electrode. The mode of binding between the nsDNA and aromatic compounds was investigated using EIS, indicating that the dominant interaction is non-covalent. nsDNA based biosensor was observed to act as an efficient biosensor in selective and sensitive identification of aromatic compounds.

  11. Methods for determination of toxic organic compounds in air

    SciTech Connect

    Winberry, W.T. Jr.

    1990-01-01

    This paper provides environmental regulatory agencies, industry, and other interested parties with specific, standardized sampling and analysis procedures for toxic organic compounds in air. Compounds include Volatile Organic Compounds, Organochlorine Pesticides and PCBs, Aldehydes and Ketones, Phosgene, N-Nitrosodimethylamine, Phenol and Methylphenols (Cresols), Polychlorinated Dibenzo-p-Dioxins (PCDDs), Formaldehyde, Non-Methane Organic Compounds (NMOCs) and Polynuclear Aromatic Hydrocarbons (PAHs).

  12. Chemical effect on diffusion in intermetallic compounds

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Ting

    With the trend of big data and the Internet of things, we live in a world full of personal electronic devices and small electronic devices. In order to make the devices more powerful, advanced electronic packaging such as wafer level packaging or 3D IC packaging play an important role. Furthermore, ?-bumps, which connect silicon dies together with dimension less than 10 ?m, are crucial parts in advanced packaging. Owing to the dimension of ?-bumps, they transform into intermetallic compound from tin based solder after the liquid state bonding process. Moreover, many new reliability issues will occur in electronic packaging when the bonding materials change; in this case, we no longer have tin based solder joint, instead, we have intermetallic compound ?-bumps. Most of the potential reliability issues in intermetallic compounds are caused by the chemical reactions driven by atomic diffusion in the material; thus, to know the diffusivities of atoms inside a material is significant and can help us to further analyze the reliability issues. However, we are lacking these kinds of data in intermetallic compound because there are some problems if used traditional Darken's analysis. Therefore, we considered Wagner diffusivity in our system to solve the problems and applied the concept of chemical effect on diffusion by taking the advantage that large amount of energy will release when compounds formed. Moreover, by inventing the holes markers made by Focus ion beam (FIB), we can conduct the diffusion experiment and obtain the tracer diffusivities of atoms inside the intermetallic compound. We applied the technique on Ni3Sn4 and Cu3Sn, which are two of the most common materials in electronic packaging, and the tracer diffusivities are measured under several different temperatures; moreover, microstructure of the intermetallic compounds are investigated to ensure the diffusion environment. Additionally, the detail diffusion mechanism was also discussed in aspect of diffusion

  13. Determining the effects of a mixture of an endocrine disrupting compound, 17a-ethinylestradiol, and ammonia on fathead minnow (Pimephales promelas) reproduction

    EPA Science Inventory

    Aquatic organisms are exposed to a multitude of contaminants and to fully understand the impact of multiple stressors on fish populations, we must first understand the mechanism of action for each toxicant and how the combined effects manifest at the level of the individual. 17α-...

  14. Oxygen determination in organic fluorine compounds by means of a glassy-carbon pyrolysis tube.

    PubMed

    Imaeda, K; Kuriki, T; Ohsawa, K

    1977-07-01

    A conventional apparatus for determination of oxygen in organic compounds has been improved for application to organic fluorine compounds. A feature of the apparatus is the use of a pyrolysis tube made of glassy carbon instead of quartz, which eliminates effects due to hydrogen fluoride produced in pyrolysis of the sample. Ten analyses of dexamethasone with the apparatus gave a mean value of 20.44% for oxygen (theory, 20.38%), with a standard deviation of 0.16%. Oxygen in 9 organic fluorine compounds was accurately determined by using the apparatus, with an average error of +0.1%. One analysis by a gravimetric or a coulometric method took about 40 or 25 min, respectively.

  15. Quantitative method of determining beryllium or a compound thereof in a sample

    DOEpatents

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2010-08-24

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  16. Quantitative method of determining beryllium or a compound thereof in a sample

    DOEpatents

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2006-10-31

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  17. Effects of polyhydroxy compounds on beetle antifreeze protein activity

    PubMed Central

    Amornwittawat, Natapol; Wang, Sen; Banatlao, Joseph; Chung, Melody; Velasco, Efrain; Duman, John G.; Wen, Xin

    2016-01-01

    Antifreeze proteins (AFPs) noncolligatively depress the nonequilibrium freezing point of a solution and produce a difference between the melting and freezing points termed thermal hysteresis (TH). Some low-molecular-mass solutes can affect the TH values. The TH enhancement effects of selected polyhydroxy compounds including polyols and carbohydrates on an AFP from the beetle Dendroides canadensis were systematically investigated using differential scanning calorimetry (DSC). The number of hydroxyl groups dominates the molar enhancement effectiveness of polyhydroxy compounds having one to five hydroxyl groups. However, the above rule does not apply for polyhydroxy compounds having more than five hydroxyl groups. The most efficient polyhydroxy enhancer identified is trehalose. In a combination of enhancers the strongest enhancer plays the major role in determining the TH enhancement. Mechanistic insights into identification of highly efficient AFP enhancers are discussed. PMID:19038370

  18. Reading Compounds in Neglect Dyslexia: The Headedness Effect

    ERIC Educational Resources Information Center

    Semenza, Carlo; Arcara, Giorgio; Facchini, Silvia; Meneghello, Francesca; Ferraro, Marco; Passarini, Laura; Pilosio, Cristina; Vigato, Giovanna; Mondini, Sara

    2011-01-01

    Reading compound words was studied in neglect dyslexia in order to assess the influence of "headedness". The "head" of a compound is the component that determines the grammatical category, the syntactic (e.g., the gender) and the semantic properties of the compound as a whole. For example, in the word "blackberry" "berry" is the compound's head.…

  19. Effect of temperature and solvent composition on acid dissociation equilibria, I: Sequenced (s)(s)pKa determination of compounds commonly used as buffers in high performance liquid chromatography coupled to mass spectroscopy detection.

    PubMed

    Padró, Juan M; Acquaviva, Agustín; Tascon, Marcos; Gagliardi, Leonardo G; Castells, Cecilia B

    2012-05-01

    A new automated and rapid potentiometric method for determining the effect of organic-solvent composition on pK(a) has been developed. It is based on the measurements of pH values of buffer solutions of variable solvent compositions using a combined glass electrode. Additions of small volumes of one precisely thermostated solution into another, both containing exactly the same analytical concentrations of the buffer components, can produce continuous changes in the solvent composition. Two sequences of potential measurements, one of increasing and the other of decreasing solvent content, are sufficient to obtain the pK(a) values of the acidic compound within the complete solvent-composition range in about 2h. The experimental design, procedures, and calculations needed to convert the measured pH into the thermodynamic pK(a) values are thoroughly discussed. This rapid and automated method allows the systematic study of the effect of solvent compositions and temperatures on the pK(a). It has been applied to study the dissociation constants of two monoprotic acids: formic acid and triethylamine:HCl in acetonitrile/water mixtures within the range from 0 to 90% (v/v) at temperatures between 20°C and 60°C. These volatile compounds are frequently used to control the pH of the mobile phase in HPLC, especially in methods coupled to mass-spectrometry detection. The obtained pK(a) values are in excellent agreement with those previously reported. The results were fitted to empirical functions between pK(a) and temperature and composition. These equations, which can be used to estimate the pK(a) of these substances at any composition and temperature, would be highly useful in practical work during chromatographic method development.

  20. Determination of acidity constants of enolisable compounds by capillary electrophoresis.

    PubMed

    Mofaddel, N; Bar, N; Villemin, D; Desbène, P L

    2004-10-01

    Research on the structure-activity relationships of molecules with acidic carbon atoms led us to undertake a feasibility study on the determination of their acidity constants by capillary electrophoresis (CE). The studied molecules had diverse structures and were tetronic acid, acetylacetone, diethylmalonate, Meldrum's acid, 3-methylrhodanine, nitroacetic acid ethyl ester, pyrimidine-2,4,6-trione, 3-oxo-3-phenylpropionic acid ethyl ester, 1-phenylbutan-1,3-dione, 5,5-dimethylcyclohexan-1,3-dione and homophthalic anhydride. The p Ka range explored by CE was therefore very large (from 3 to 12) and p Ka values near 12 were evaluated by mathematical extrapolations. The analyses were carried out in CZE mode using a fused silica capillary grafted (or not) with hexadimethrine. Owing to the electrophoretic behaviour of these compounds according to the pH, their acidity constants could be evaluated and appeared in perfect agreement with the literature data obtained, a few decades ago, by means of potentiometry, spectrometry or conductimetry. The p Ka of homophthalic anhydride and 3-methylrhodanine were evaluated for the first time.

  1. Method for determination of some soluble atmospheric carbonyl compounds

    SciTech Connect

    Lee, Y.N.; Zhou, X. )

    1993-04-01

    A technique was developed for the measurement of soluble atmospheric carbonyl compounds, which uses a pyrex coil gas-liquid scrubber sampler in conjunction with a high-performance liquid chromatograph equipped with a UV-visible detector for separation and identification following derivatization with 2,4-dinitrophenylhydrazine. Carbonyls exhibiting a Henry's law solubility similar to or greater than that of formaldehyde (FA) can be determined by this method; these include FA, glycolaldehyde (GA), glyoxal (GL), and methylglyoxal (MG). Based on liquid standards and field-developed chromatographic characteristics, the limits of detection are about 0.005 ppb (in the gas phase) for MG, about 0.01 ppb for GL, and about 0.02 ppb for FA and GA. Because of the short air-liquid contact time in the coil sampler (smaller than 10 s), interferences from aqueous-phase reactions of ozone are insignificant. Also, at the low pH of the scrubbing solution, interference resulting from reactions of carbonyls with S(IV) is unimportant. 43 refs., 7 figs., 3 tabs.

  2. Bioactive Compounds and Their Neuroprotective Effects in Diabetic Complications

    PubMed Central

    Oh, Yoon Sin

    2016-01-01

    Hyperglycemia, hyperlipidemia and impaired insulin signaling during the development of diabetes can cause diabetic complications, such as diabetic neuropathy, resulting in significant morbidity and mortality. Although various therapeutics are available for the treatment of diabetic neuropathy, no absolute cure exists, and additional research is necessary to comprehensively understand the underlying pathophysiological pathways. A number of studies have demonstrated the potential health benefits of bioactive compounds, i.e., flavonoids and vitamins, which may be effective as supplementary treatments for diabetes and its complications. In this review, we highlight the most recent reports about the mechanisms of action of bioactive compounds (flavonoids and vitamins) possessing potential neuroprotective properties in diabetic conditions. Additional clinical studies are required to determine the appropriate dose and duration of bioactive compound supplementation for neuroprotection in diabetic patients. PMID:27483315

  3. Bioactive Compounds and Their Neuroprotective Effects in Diabetic Complications.

    PubMed

    Oh, Yoon Sin

    2016-01-01

    Hyperglycemia, hyperlipidemia and impaired insulin signaling during the development of diabetes can cause diabetic complications, such as diabetic neuropathy, resulting in significant morbidity and mortality. Although various therapeutics are available for the treatment of diabetic neuropathy, no absolute cure exists, and additional research is necessary to comprehensively understand the underlying pathophysiological pathways. A number of studies have demonstrated the potential health benefits of bioactive compounds, i.e., flavonoids and vitamins, which may be effective as supplementary treatments for diabetes and its complications. In this review, we highlight the most recent reports about the mechanisms of action of bioactive compounds (flavonoids and vitamins) possessing potential neuroprotective properties in diabetic conditions. Additional clinical studies are required to determine the appropriate dose and duration of bioactive compound supplementation for neuroprotection in diabetic patients. PMID:27483315

  4. Analytical Methodologies for the Determination of Endocrine Disrupting Compounds in Biological and Environmental Samples

    PubMed Central

    Sosa-Ferrera, Zoraida; Mahugo-Santana, Cristina; Santana-Rodríguez, José Juan

    2013-01-01

    Endocrine-disruptor compounds (EDCs) can mimic natural hormones and produce adverse effects in the endocrine functions by interacting with estrogen receptors. EDCs include both natural and synthetic chemicals, such as hormones, personal care products, surfactants, and flame retardants, among others. EDCs are characterised by their ubiquitous presence at trace-level concentrations and their wide diversity. Since the discovery of the adverse effects of these pollutants on wildlife and human health, analytical methods have been developed for their qualitative and quantitative determination. In particular, mass-based analytical methods show excellent sensitivity and precision for their quantification. This paper reviews recently published analytical methodologies for the sample preparation and for the determination of these compounds in different environmental and biological matrices by liquid chromatography coupled with mass spectrometry. The various sample preparation techniques are compared and discussed. In addition, recent developments and advances in this field are presented. PMID:23738329

  5. Determination of polycyclic aromatic compounds in fish tissue.

    PubMed

    Birkholz, D A; Coutts, R T; Hrudey, S E

    1988-09-30

    A method is presented for the analysis of polycyclic aromatic hydrocarbons (PAHs), polycyclic aromatic sulfur heterocycles (PASHs), and basic polycyclic aromatic nitrogen heterocycles (PANHs) in fish. The analytical procedure includes Soxhlet extraction of prepared fish tissue with methylene chloride followed by gel permeation chromatography (GPC) using Bio-beads SX-3. For PAHs/PASHs, further cleanup is performed using adsorption chromatography on Florisil (5% water deactivated) and elution with hexane. For basic PANHs further cleanup of the fish extracts after GPC is achieved using liquid-liquid partitioning with 6 M hydrochloric acid and chloroform and then basifying the aqueous phase and extracting it with chloroform. Analysis of fortified fish samples was performed using capillary gas chromatography with flame ionization detection and capillary gas chromatography-mass spectrometry. Good agreement was observed for both methods of analysis when applied to fish samples fortified with PAHs, PASHs and basic PANHs at 0.1 to 1 microgram/g, suggesting that the method is effective at removing interfering biogenic compounds prior to analysis. Average recovery of PAHs/PASHs from fortified fish tissue was 87% and 70% for fish tissue fortified at 0.24-1.1 and 0.024-0.11 microgram/g, respectively. Average recovery for basic PANHs was 97% for fish fortified at 1.2-1.4 micrograms/g.

  6. Determining drug release rates of hydrophobic compounds from nanocarriers.

    PubMed

    D'Addio, Suzanne M; Bukari, Abdallah A; Dawoud, Mohammed; Bunjes, Heike; Rinaldi, Carlos; Prud'homme, Robert K

    2016-07-28

    Obtaining meaningful drug release profiles for drug formulations is essential prior to in vivo testing and for ensuring consistent quality. The release kinetics of hydrophobic drugs from nanocarriers (NCs) are not well understood because the standard protocols for maintaining sink conditions and sampling are not valid owing to mass transfer and solubility limitations. In this work, a new in vitroassay protocol based on 'lipid sinks' and magnetic separation produces release conditions that mimic the concentrations of lipid membranes and lipoproteins in vivo, facilitates separation, and thus allows determination of intrinsic release rates of drugs from NCs. The assay protocol is validated by (i) determining the magnetic separation efficiency, (ii) demonstrating that sink condition requirements are met, and (iii) accounting for drug by completing a mass balance. NCs of itraconazole and cyclosporine A (CsA) were prepared and the drug release profiles were determined. This release protocol has been used to compare the drug release from a polymer stabilized NC of CsA to a solid drug NP of CsA alone. These data have led to the finding that stabilizing block copolymer layers have a retarding effect on drug release from NCs, reducing the rate of CsA release fourfold compared with the nanoparticle without a polymer coating.This article is part of the themed issue 'Soft interfacial materials: from fundamentals to formulation'.

  7. Determination of volatile marker compounds of common coffee roast defects.

    PubMed

    Yang, Ni; Liu, Chujiao; Liu, Xingkun; Degn, Tina Kreuzfeldt; Munchow, Morten; Fisk, Ian

    2016-11-15

    Coffee beans from the same origin were roasted using six time-temperature profiles, in order to identify volatile aroma compounds associated with five common roast coffee defects (light, scorched, dark, baked and underdeveloped). Thirty-seven volatile aroma compounds were selected on the basis that they had previously been identified as potent odorants of coffee and were also identified in all coffee brew preparations; the relative abundance of these aroma compounds was then evaluated using gas chromatography mass spectrometry (GC-MS) with headspace solid phase micro extraction. Some of the 37 key aroma compounds were significantly changed in each coffee roast defect and changes in one marker compound was chosen for each defect type, that is, indole for light defect, 4-ethyl-2-methoxyphenol for scorched defect, phenol for dark defect, maltol for baked defect and 2,5-dimethylfuran for underdeveloped defect. The association of specific changes in aroma profiles for different roast defects has not been shown previously and could be incorporated into screening tools to enable the coffee industry quickly identify if roast defects occur during production. PMID:27283624

  8. Beer and beer compounds: physiological effects on skin health.

    PubMed

    Chen, W; Becker, T; Qian, F; Ring, J

    2014-02-01

    Beer is one of the earliest human inventions and globally the most consumed alcoholic beverage in terms of volume. In addition to water, the 'German Beer Purity Law', based on the Bavarian Beer Purity Law from 1516, allows only barley, hops, yeasts and water for beer brewing. The extracts of these ingredients, especially the hops, contain an abundance of polyphenols such as kaempferol, quercetin, tyrosol, ferulic acid, xanthohumol/isoxanthohumol/8-prenylnaringenin, α-bitter acids like humulone and β-bitter acids like lupulone. 8-prenylnaringenin is the most potent phytoestrogen known to date. These compounds have been shown to possess various anti-bacterial, anti-inflammatory, anti-oxidative, anti-angiogenic, anti-melanogenic, anti-osteoporotic and anti-carcinogenic effects. Epidemiological studies on the association between beer drinking and skin disease are limited while direct evidence of beer compounds in clinical application is lacking. Potential uses of these substances in dermatology may include treatment of atopic eczema, contact dermatitis, pigmentary disorders, skin infections, skin ageing, skin cancers and photoprotections, which require an optimization of the biostability and topical delivery of these compounds. Further studies are needed to determine the bioavailability of these compounds and their possible beneficial health effects when taken by moderate beer consumption. PMID:23802910

  9. Beer and beer compounds: physiological effects on skin health.

    PubMed

    Chen, W; Becker, T; Qian, F; Ring, J

    2014-02-01

    Beer is one of the earliest human inventions and globally the most consumed alcoholic beverage in terms of volume. In addition to water, the 'German Beer Purity Law', based on the Bavarian Beer Purity Law from 1516, allows only barley, hops, yeasts and water for beer brewing. The extracts of these ingredients, especially the hops, contain an abundance of polyphenols such as kaempferol, quercetin, tyrosol, ferulic acid, xanthohumol/isoxanthohumol/8-prenylnaringenin, α-bitter acids like humulone and β-bitter acids like lupulone. 8-prenylnaringenin is the most potent phytoestrogen known to date. These compounds have been shown to possess various anti-bacterial, anti-inflammatory, anti-oxidative, anti-angiogenic, anti-melanogenic, anti-osteoporotic and anti-carcinogenic effects. Epidemiological studies on the association between beer drinking and skin disease are limited while direct evidence of beer compounds in clinical application is lacking. Potential uses of these substances in dermatology may include treatment of atopic eczema, contact dermatitis, pigmentary disorders, skin infections, skin ageing, skin cancers and photoprotections, which require an optimization of the biostability and topical delivery of these compounds. Further studies are needed to determine the bioavailability of these compounds and their possible beneficial health effects when taken by moderate beer consumption.

  10. Effect of cooking on physicochemical properties and volatile compounds in lotus root (Nelumbo nucifera Gaertn).

    PubMed

    Li, Shuyi; Li, Xiaojin; Lamikanra, Olusola; Luo, Qing; Liu, Zhiwei; Yang, Jun

    2017-02-01

    The effects of boiling and steaming on lotus root volatile compounds and some of its physicochemical properties were determined. A total of 52 compounds identified in the raw tuber by GC-MS were a combination of the rhizome's native compounds and those from the soil and water environment, and are predominantly a mixture of straight chain and cyclic alkanes, and aromatic hydrocarbons. Boiling increased concentrations of most of these compounds, unlike steaming that lowered total volatile components of the tuber. Cooking increased complexity of volatile compounds with the production of new compounds such as methylated derivatives, particularly in steam cooked lotus. Other heat-induced compounds include antioxidants such as butylated hydroxyl compounds and antifungal organic compounds such as dimethyl disulfide. Instrumental texture measurements indicate that the characteristic post-cooked retention of crunchiness in lotus root is likely to be related to retention of its springiness index through the cooking process. PMID:27596426

  11. DETERMINATION OF ORGANOPHOSPHORUS COMPOUNDS BY GC-ICPMS

    EPA Science Inventory

    Accidental or intentional release of neurotoxic organophosphorus (OP) pesticides and OP chemical warfare agents (CWAs) are potential threats to public health and the environment. Such a release could involve any number of a large suite of OP chemicals. These compounds, as well a...

  12. A Standardized Sampling Procedure for the Determination of Volatile Organic Compounds (VOC) Determined in Snow Samples

    NASA Astrophysics Data System (ADS)

    Kos, G.; Ariya, P. A.

    2005-12-01

    Snow samples were collected from different semi-remote and urban environments using a standardized sampling procedure in order to minimize sampling errors. Samples were collected in pre-cleaned amber glass and sterile HDPE containers. Glass bottles and all non-sterilized equipment were washed with low nutrient detergent, acid washed and rinsed with ultra-pure water. Samples were collected using pre-sterilized or acid-washed sampling tools and blanks, consisting of ultra-pure water, which were treated identically to the collected samples in to monitor contamination from sampling equipment and the different types of containers. Analysis for VOC was carried out with a previously described, but modified solid phase micro-extraction (SPME) pre-concentration method and determination of compounds using gas-chromatography with mass spectrometric detection (GC-MS) (1). Low concentrations required the use of larger sample volumes and splitless injection mode. Samples analyzed were collected in and around Montreal, Quebec (45.28 N/73.45 W) at Mont-Saint Hilaire (altitude: 415 m a.s.l.), Downtown Montreal and Parc Tremblant. We will present and compare results from all sites, and the implication for atmospheric processes will be discussed. References (1) Kos G, Ariya PA (2004), Determination of Volatile Organic Compounds in Snow Using Solid Phase Micro Extraction, Eos Trans. AGU, 85 (47), Fall Meet. Suppl., Abstract A11B-53

  13. 76 FR 53907 - Determination That TALWIN COMPOUND (Aspirin; Pentazocine Hydrochloride) Tablets, 325 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... HUMAN SERVICES Food and Drug Administration Determination That TALWIN COMPOUND (Aspirin; Pentazocine... Food and Drug Administration (FDA) has determined that TALWIN COMPOUND (aspirin; pentazocine... drug applications (ANDAs) for aspirin; pentazocine HCl tablets, 325 mg; EQ 12.5 mg base, if all...

  14. Determination of biodegradability kinetics of RCRA compounds using respirometry for structure-activity relationships

    SciTech Connect

    Tabak, H.H.; Desai, S.; Govind, R.

    1990-01-01

    Electrolytic respirometry is attaining prominence in biodegradation studies and is becoming one of the more suitable experimental methods for measuring the biodegradability and the kinetics of biodegradation of toxic organic compounds by the sewage, sludge, and soil microbiota and for determining substrate inhibitory effects to microorganisms in wastewater treatment systems. The purpose of the study was to obtain information on biological treatability of the benzene, phenol, phthalate, ketone organics and of the Superfund CERCLA organics bearing wastes in wastewater treatment systems which will support the development of an EPA technical guidance document on the discharge of the above organics to POTWs. The paper discusses the experimental design and procedural steps for the respirometric biodegradation and toxicity testing approach for individual organics or specific industrial wastes at different concentration levels in a mineral salts medium. A developed multi-level protocol is presented for determination of the biodegradability, microbial acclimation to toxic substrates and first order kinetic parameters of biodegradation for estimation of the Monod kinetic parameter of toxic organic compounds, in order to correlate the extent and rate of biodegradation with a predictive model based on chemical properties and molecular structure of these compounds. Respirometric biodegradation/inhibition and biokinetic data are provided for representative RCRA alkyl benzene and ketone organics.

  15. Simple nanoparticle-based luminometric method for molecular weight determination of polymeric compounds.

    PubMed

    Pihlasalo, Sari; Virtamo, Maria; Legrand, Nicolas; Hänninen, Pekka; Härmä, Harri

    2014-01-21

    A nanoparticle-based method utilizing time-resolved luminescence resonance energy transfer (TR-LRET) was developed for molecular weight determination. This mix-and-measure nanoparticle method is based on the competitive adsorption between the analyte and the acceptor-labeled protein to donor Eu(III) nanoparticles. The size-dependent adsorption of molecules enables the molecular weight determination of differently sized polymeric compounds down to a concentration level of micrograms per liter. The molecular weight determination from 1 to 10 kDa for polyamino acids and from 0.3 to 70 kDa for polyethylene imines is demonstrated. The simple and cost-effective nanoparticle method as microtiter plate assay format shows great potential for the detection of the changes in molecular weight or for quantification of differently sized molecules in biochemical laboratories and in industrial polymeric processes.

  16. Effect of intermediate compounds and products on wet oxidation and biodegradation rates of pharmaceutical compounds.

    PubMed

    Collado, Sergio; Laca, Adriana; Diaz, Mario

    2013-06-01

    Kinetics of pure compounds in batch agitated reactors are useful data to clarify the characteristics of a given reaction, but they frequently do not provide the required information to design industrial mixed continuous processes because in this case the final and intermediate products interact with the reaction of interest, due to backmixing effects. Simultaneously, the presence and transformations of other compounds, frequent in industrial wastewater treatments, adds more complexity to these types of interactions, whose effect can be different, favorable or unfavorable, for chemical or biological reactions. In this work, batch laboratory reactor data were obtained for the wet oxidation and biodegradation of four phenolic compounds present in a pharmaceutical wastewater and then compared with those collected from industrial continuous stirred tank reactors. For wet oxidation, batch laboratory degradation rates were significantly lower than those found in industrial continuous stirred operation. This behavior was explained by a different distribution of intermediate compounds in lab and industrial treatments, caused by the degree of backmixing and the synergistic effects between phenolic compounds (matrix effects). On the other hand, the specific utilization rates during aerobic biodegradation in the continuous industrial operation were lower than those measured in the laboratory, due to the simultaneous presence of the four pollutants in the industrial process (matrix effects) increasing the inhibitory effects of these compounds and its intermediates.

  17. Determination of acidity constants by the capillary electrophoresis internal standard method. IV. Polyprotic compounds.

    PubMed

    Cabot, Joan Marc; Fuguet, Elisabet; Ràfols, Clara; Rosés, Martí

    2013-03-01

    The IS-CE method is developed for pK(a) determination of polyprotic compounds. In this method, the internal standard (IS) and the polyprotic test compound are injected into the capillary electrophoresis (CE) system in buffers with appropriate pH. The pH of the buffers is not externally measured, but determined inside the capillary from the mobilities of the internal standards. Then the pK(a) values of the polyprotic compounds are obtained by fitting its mobilities to the in situ pH values. The method is faster than the classical CE method (a diprotic compound can be done in less than 15 min), and also than other methods like potentiometric and spectrophotometric titrations. The method has been successfully applied to 20 polyprotic test compounds of different chemical nature, including compounds with extreme or very close pK(a) values.

  18. METHOD DEVELOPMENT FOR THE DETERMINATION OF PERFLUORINATED ORGANIC COMPOUNDS ( PFCS ) IN SURFACE WATER

    EPA Science Inventory

    The method for the determination of perfluorinated organic compounds (PFCs) in surface water has been developed and applied to natural water. The method shows an adequate sensitivity, precision and accuracy for ten kinds of target compounds. These PFCs were found in most samples...

  19. Dilution standard addition calibration: A practical calibration strategy for multiresidue organic compounds determination.

    PubMed

    Martins, Manoel L; Rizzetti, Tiele M; Kemmerich, Magali; Saibt, Nathália; Prestes, Osmar D; Adaime, Martha B; Zanella, Renato

    2016-08-19

    Among calibration approaches for organic compounds determination in complex matrices, external calibration, based in solutions of the analytes in solvent or in blank matrix extracts, is the most applied approach. Although matrix matched calibration (MMC) can compensates the matrix effects, it does not compensate low recovery results. In this way, standard addition (SA) and procedural standard calibration (PSC) are usual alternatives, despite they generate more sample and/or matrix blanks consumption need, extra sample preparations and higher time and costs. Thus, the goal of this work was to establish a fast and efficient calibration approach, the diluted standard addition calibration (DSAC), based on successive dilutions of a spiked blank sample. In order to evaluate the proposed approach, solvent calibration (SC), MMC, PSC and DSAC were applied to evaluate recovery results of grape blank samples spiked with 66 pesticides. Samples were extracted with the acetate QuEChERS method and the compounds determined by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Results indicated that low recovery results for some pesticides were compensated by both PSC and DSAC approaches. Considering recoveries from 70 to 120% with RSD <20% as adequate, DSAC presented 83%, 98% and 100% of compounds meeting this criteria for the spiking levels 10, 50 and 100μgkg(-1), respectively. PSC presented same results (83%, 98% and 100%), better than those obtained by MMC (79%, 95% and 97%) and by SC (62%, 70% and 79%). The DSAC strategy showed to be suitable for calibration of multiresidue determination methods, producing adequate results in terms of trueness and is easier and faster to perform than other approaches. PMID:27432791

  20. Dilution standard addition calibration: A practical calibration strategy for multiresidue organic compounds determination.

    PubMed

    Martins, Manoel L; Rizzetti, Tiele M; Kemmerich, Magali; Saibt, Nathália; Prestes, Osmar D; Adaime, Martha B; Zanella, Renato

    2016-08-19

    Among calibration approaches for organic compounds determination in complex matrices, external calibration, based in solutions of the analytes in solvent or in blank matrix extracts, is the most applied approach. Although matrix matched calibration (MMC) can compensates the matrix effects, it does not compensate low recovery results. In this way, standard addition (SA) and procedural standard calibration (PSC) are usual alternatives, despite they generate more sample and/or matrix blanks consumption need, extra sample preparations and higher time and costs. Thus, the goal of this work was to establish a fast and efficient calibration approach, the diluted standard addition calibration (DSAC), based on successive dilutions of a spiked blank sample. In order to evaluate the proposed approach, solvent calibration (SC), MMC, PSC and DSAC were applied to evaluate recovery results of grape blank samples spiked with 66 pesticides. Samples were extracted with the acetate QuEChERS method and the compounds determined by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Results indicated that low recovery results for some pesticides were compensated by both PSC and DSAC approaches. Considering recoveries from 70 to 120% with RSD <20% as adequate, DSAC presented 83%, 98% and 100% of compounds meeting this criteria for the spiking levels 10, 50 and 100μgkg(-1), respectively. PSC presented same results (83%, 98% and 100%), better than those obtained by MMC (79%, 95% and 97%) and by SC (62%, 70% and 79%). The DSAC strategy showed to be suitable for calibration of multiresidue determination methods, producing adequate results in terms of trueness and is easier and faster to perform than other approaches.

  1. Volatile Compounds in Honey: A Review on Their Involvement in Aroma, Botanical Origin Determination and Potential Biomedical Activities

    PubMed Central

    Manyi-Loh, Christy E.; Ndip, Roland N.; Clarke, Anna M.

    2011-01-01

    Volatile organic compounds (VOCs) in honey are obtained from diverse biosynthetic pathways and extracted by using various methods associated with varying degrees of selectivity and effectiveness. These compounds are grouped into chemical categories such as aldehyde, ketone, acid, alcohol, hydrocarbon, norisoprenoids, terpenes and benzene compounds and their derivatives, furan and pyran derivatives. They represent a fingerprint of a specific honey and therefore could be used to differentiate between monofloral honeys from different floral sources, thus providing valuable information concerning the honey’s botanical and geographical origin. However, only plant derived compounds and their metabolites (terpenes, norisoprenoids and benzene compounds and their derivatives) must be employed to discriminate among floral origins of honey. Notwithstanding, many authors have reported different floral markers for honey of the same floral origin, consequently sensory analysis, in conjunction with analysis of VOCs could help to clear this ambiguity. Furthermore, VOCs influence honey’s aroma described as sweet, citrus, floral, almond, rancid, etc. Clearly, the contribution of a volatile compound to honey aroma is determined by its odor activity value. Elucidation of the aroma compounds along with floral origins of a particular honey can help to standardize its quality and avoid fraudulent labeling of the product. Although only present in low concentrations, VOCS could contribute to biomedical activities of honey, especially the antioxidant effect due to their natural radical scavenging potential. PMID:22272147

  2. Determination of sulfur compounds in hydrotreated transformer base oil by potentiometric titration.

    PubMed

    Chao, Qiu; Sheng, Han; Cheng, Xingguo; Ren, Tianhui

    2005-06-01

    A method was developed to analyze the distribution of sulfur compounds in model sulfur compounds by potentiometric titration, and applied to analyze hydrotreated transformer base oil. Model thioethers were oxidized to corresponding sulfoxides by tetrabutylammonium periodate and sodium metaperiodate, respectively, and the sulfoxides were titrated by perchloric acid titrant in acetic anhydride. The contents of aliphatic thioethers and total thioethers were then determined from that of sulfoxides in solution. The method was applied to determine the organic sulfur compounds in hydrotreated transformer base oil.

  3. Determination of endocrine disrupting compounds and their metabolites in fish bile.

    PubMed

    Ros, Oihana; Izaguirre, Jon Kepa; Olivares, Maitane; Bizarro, Cristina; Ortiz-Zarragoitia, Maren; Cajaraville, Miren Pilar; Etxebarria, Nestor; Prieto, Ailette; Vallejo, Asier

    2015-12-01

    This work describes a new methodology for the simultaneous determination of a large variety of emerging and persistent organic compounds and some of their metabolites in fish bile samples. The target compounds were musk fragrances, alkyl phenols, hormones, pesticides, phthalate esters and bisphenol-A, all of them with a known endocrine disrupting effect. To achieve the determination these three steps were optimized: i) an enzymatic hydrolysis of the metabolites to render the unconjugated compounds; ii) the solid phase extraction of the target analytes (Plexa cartridges 200-mg); and, iii) a clean-up of the extracts (Florisil cartridges 1-g). The samples were analyzed by gas-chromatography-mass spectrometry (GC-MS), though the polar fraction required a previous derivatization with O-bis (trimethylsilyl) trifluoroacetamide. Good apparent recoveries (63-122%), repeatability (<20%) and limits of detection (LODs) ranging between 0.04 and 459 ng/mL were obtained. This method was applied to the analysis of the target analytes in bile samples of thicklip grey mullets (Chelon labrosus) from five different populations of the Basque Coast (South East Bay of Biscay) during the period of May-June 2012. The target analytes were found at concentrations ranging from

  4. Simple and fast determination of perfluorinated compounds in Taihu Lake by SPE-UHPLC-MS/MS.

    PubMed

    Zhu, Pengfei; Ling, Xia; Liu, Wenwei; Kong, Lingcan; Yao, Yuyang

    2016-09-15

    A simple and fast analytical method for determination of eleven Polyfluorinated Compounds (PFCs) in source water was developed in the present work. The water sample was prepared without filtered through microfiltration membrane and 500mL of source water was enriched by the solid phase extraction (SPE). The targent compounds were analyzed by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The optimized analytical method was validated in terms of recovery, precision and method detection limits (MDLs). The recovery values after correction with the corresponding labeled standard were between 97.3 and 113.0% for samples spiked at 5ng/L, 10ng/L and 20ng/L. All PFCs showed good linearity and the linear correlation coefficient was over 0.99. The precisions were 1.0-9.0% (n=6). As the result of the enrichment, the MDL values ranged from 0.03 to 1.9ng/L and were enough for analysis of the trace levels of PFCs in the Taihu Lake. The method was further validated in determining the source water and the results showed that PFHxS, PFHxA, PFOA and PFOS were the primary PFCs in Taihu Lake which might be different from the other researches. The method can be used for determination of PFCs in water with a stable recovery, good reproducibility, low detection limit, less solvent consumption, time saving and labor saving. To our knowledge, this is the first method that describes the effect of the filter membrane on the determination of PFCs in water which might acquire more accurate concentration of PFCs in Taihu Lake. PMID:27454901

  5. Nitroaromatic munition compounds: environmental effects and screening values.

    PubMed

    Talmage, S S; Opresko, D M; Maxwell, C J; Welsh, C J; Cretella, F M; Reno, P H; Daniel, F B

    1999-01-01

    final chronic value) according to USEPA guidelines. Available data indicate that none of the compounds is expected to bioconcentrate. In the same manner in which reference doses for humans are based on studies with laboratory animals, reference doses or screening benchmarks for wildlife may also be calculated by extrapolation among mammalian species. Chronic NOAELs for the compounds of interest were determined from available laboratory studies. Endpoints selected for wildlife species were those that diminish population growth or survival. Equivalent NOAELs for wildlife were calculated by scaling the test data on the basis of differences in body weight. Data on food and water intake for seven selected wildlife species--short-tailed shrew, white-footed mouse, meadow vole, cottontail rabbit, mink, red fox, and whitetail deer--were used to calculate NOAELs for oral intake. In the case of TNB, a comparison of toxicity data from studies conducted with both the white-footed mouse and the laboratory rat indicates that the white-footed mouse may be more resistant to the toxic effects of chemicals than the laboratory rat and may further indicate the lesser sensitivity of wildlife species to chemical insult. Chronic NOAEL values for the test species based on the laboratory studies indicate that, by the oral route of exposure, TNB and RDX are not highly toxic to mammalian species. However, as seen with TNB, values are less conservative when chronic studies are available or when studies were conducted with wildlife species. Insufficient data were located to calculate NOAELs for avian species. In the absence of criteria or guidelines for terrestrial plants, invertebrates, and soil heterotrophic processes, LOECs were used as screening benchmarks for effect levels in the environment. In most cases, too few data were available to derive a screening benchmark or to have a high degree of confidence in the benchmarks that were derived. (ABSTRACT TRUNCATED) PMID:10218448

  6. Phenolic compounds from Allium schoenoprasum, Tragopogon pratensis and Rumex acetosa and their antiproliferative effects.

    PubMed

    Kucekova, Zdenka; Mlcek, Jiri; Humpolicek, Petr; Rop, Otakar; Valasek, Pavel; Saha, Petr

    2011-11-03

    Experimental studies have shown that phenolic compounds have antiproliferative and tumour arresting effects. The aim of this original study was to investigate the content of phenolic compounds (PhC) in flowers of Allium schoenoprasum (chive), Tragopogon pratensis (meadow salsify) and Rumex acetosa (common sorrel) and their effect on proliferation of HaCaT cells. Antiproliferative effects were evaluated in vitro using the following concentrations of phenolic compounds in cultivation medium: 100, 75, 50 and 25 µg/mL. Phenolic composition was also determined by HPLC. The results indicate that even low concentrations of these flowers' phenolic compounds inhibited cell proliferation significantly and the possible use of the studied herb's flowers as sources of active phenolic compounds for human nutrition.

  7. Methods to determine antipathogenic potential of phenolic and flavonoid compounds against urinary pathogen Serratia marcescens.

    PubMed

    Annapoorani, Angusamy; Parameswari, Radhakrishnan; Pandian, Shunmugiah Karutha; Ravi, Arumugam Veera

    2012-10-01

    This study revealed the antipathogenic potential of natural compounds present in the edible fruits against urinary pathogen Serratia marcescens by using quorum sensing inhibition (QSI). The serum resistance assay was adopted to examine the immunomodulatory effects of QSI compounds to fight against bacterial infections.

  8. RISKS OF ENDROCRINE DISRUPTING COMPOUNDS TO WILDLIFE EXTRAPOLATED FROM EFFECTS ON INDIVIDUALS TO POPULATION RESPONSE

    EPA Science Inventory

    Much of the research conducted on the effects of endocrine disrupting compounds (EDCs) has been focused on effects at the individual or sub-individual level. The challenge from the point of view of ecological risk assessment is to determine effects on populations and higher level...

  9. Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

    USGS Publications Warehouse

    Hinckley, D.A.; Bidleman, T.F.; Foreman, W.T.; Tuschall, J.R.

    1990-01-01

    Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

  10. Antioxidative effect of sesamol and related compounds on lipid peroxidation.

    PubMed

    Uchida, M; Nakajin, S; Toyoshima, S; Shinoda, M

    1996-04-01

    The effect of sesamol and 20 related compounds on the lipid peroxidation of liposomes induced by Fe(2)+, on the lipid peroxidation of rat liver microsomes induced by CCl(4) or NADPH and on the lipid peroxidation of mitochondria induced by ascorbate/Fe(2)+ were demonstrated. Consequently, sesamol and related compounds, such as 3-methoxy-4-hydroxyquinone, isosafrol, isoeugenol, eugenol, 3,4-methylenedioxyaniline, catechol, hydroxy-hydroquinone, 3,4-dimethoxyaniline and caffeic acid, exhibited powerful inhibitory effects on the lipid peroxidation system investigated. In particular, isoeugenol was the most powerful inhibitor among all the sesamol-related compounds tested on the lipid peroxidation system. In addition, 1,2-methylenedioxybenzene, ferulic acid, and 3,4-methylenedioxynitrobenzene were also effective on the lipid peroxidation system of liposomes induced by Fe(2)+. The correlation between the structures of sesamol-related compounds and their inhibitory effect is discussed. PMID:9132170

  11. Endocrine-disrupting effects of compounds in Danish streams.

    PubMed

    Long, Manhai; Strand, Jakob; Lassen, Pia; Krüger, Tanja; Dahllöf, Ingela; Bossi, Rossana; Larsen, Martin M; Wiberg-Larsen, Peter; Bonefeld-Jørgensen, Eva Cecilie

    2014-01-01

    Effluents from municipal wastewater-treatment plants and scattered dwellings, as well as runoff from agricultural fields, are sources of endocrine-disrupting compounds (EDCs) in the aquatic environment. The present study investigated the correlation between the occurrence of EDCs in nine Danish streams using passive samplers (polar organic integrative samplers and silicone membranes) and determined their possible biological effects as assessed by mammal cell cultures and the mussel (Unio tumidus). The passive samplers and mussels were exposed simultaneously at the study sites. The extracts from the passive samplers were used to measure the concentrations of EDCs and the biological effects on the estrogen (ER), androgen (AR), and aryl hydrocarbon (AhR)-receptor transactivation. Male mussels were investigated for biomarkers of endocrine effects, such as the levels of vitellogenin-like proteins measured as alkali-labile phosphate (ALP). EDC concentrations, hormone-receptor transactivation (ER, AR, AhR), and level of ALP were greater downstream of wastewater-treatment plants compared with upstream sites and sites supposed to be relatively nonimpacted by wastewater. Furthermore, there was a significant positive correlation between in vitro AhR transactivation and frequency of ALP of male mussels. We conclude that wastewater effluent is an important source of endocrine-disrupting effects in the aquatic environment and that the combination of biological effect measurements and chemical analyses based on passive sampling is useful in the assessment of the ecological state of the aquatic environment. PMID:24145922

  12. Enzymatic electrochemical detection coupled to multivariate calibration for the determination of phenolic compounds in environmental samples.

    PubMed

    Hernandez, Silvia R; Kergaravat, Silvina V; Pividori, Maria Isabel

    2013-03-15

    An approach based on the electrochemical detection of the horseradish peroxidase enzymatic reaction by means of square wave voltammetry was developed for the determination of phenolic compounds in environmental samples. First, a systematic optimization procedure of three factors involved in the enzymatic reaction was carried out using response surface methodology through a central composite design. Second, the enzymatic electrochemical detection coupled with a multivariate calibration method based in the partial least-squares technique was optimized for the determination of a mixture of five phenolic compounds, i.e. phenol, p-aminophenol, p-chlorophenol, hydroquinone and pyrocatechol. The calibration and validation sets were built and assessed. In the calibration model, the LODs for phenolic compounds oscillated from 0.6 to 1.4 × 10(-6) mol L(-1). Recoveries for prediction samples were higher than 85%. These compounds were analyzed simultaneously in spiked samples and in water samples collected close to tanneries and landfills. PMID:23598144

  13. Enzymatic electrochemical detection coupled to multivariate calibration for the determination of phenolic compounds in environmental samples.

    PubMed

    Hernandez, Silvia R; Kergaravat, Silvina V; Pividori, Maria Isabel

    2013-03-15

    An approach based on the electrochemical detection of the horseradish peroxidase enzymatic reaction by means of square wave voltammetry was developed for the determination of phenolic compounds in environmental samples. First, a systematic optimization procedure of three factors involved in the enzymatic reaction was carried out using response surface methodology through a central composite design. Second, the enzymatic electrochemical detection coupled with a multivariate calibration method based in the partial least-squares technique was optimized for the determination of a mixture of five phenolic compounds, i.e. phenol, p-aminophenol, p-chlorophenol, hydroquinone and pyrocatechol. The calibration and validation sets were built and assessed. In the calibration model, the LODs for phenolic compounds oscillated from 0.6 to 1.4 × 10(-6) mol L(-1). Recoveries for prediction samples were higher than 85%. These compounds were analyzed simultaneously in spiked samples and in water samples collected close to tanneries and landfills.

  14. Fresh broad (Vicia faba) tissue homogenate-based biosensor for determination of phenolic compounds.

    PubMed

    Ozcan, Hakki Mevlut; Sagiroglu, Ayten

    2014-08-01

    In this study, a novel fresh broad (Vicia faba) tissue homogenate-based biosensor for determination of phenolic compounds was developed. The biosensor was constructed by immobilizing tissue homogenate of fresh broad (Vicia faba) on to glassy carbon electrode. For the stability of the biosensor, general immobilization techniques were used to secure the fresh broad tissue homogenate in gelatin-glutaraldehyde cross-linking matrix. In the optimization and characterization studies, the amount of fresh broad tissue homogenate and gelatin, glutaraldehyde percentage, optimum pH, optimum temperature and optimum buffer concentration, thermal stability, interference effects, linear range, storage stability, repeatability and sample applications (Wine, beer, fruit juices) were also investigated. Besides, the detection ranges of thirteen phenolic compounds were obtained with the help of the calibration graphs. A typical calibration curve for the sensor revealed a linear range of 5-60 μM catechol. In reproducibility studies, variation coefficient (CV) and standard deviation (SD) were calculated as 1.59%, 0.64×10(-3) μM, respectively.

  15. Effect of Se treatment on the volatile compounds in broccoli.

    PubMed

    Lv, Jiayu; Wu, Jie; Zuo, Jinhua; Fan, Linlin; Shi, Junyan; Gao, Lipu; Li, Miao; Wang, Qing

    2017-02-01

    Broccoli contains high levels of bioactive compounds but deteriorates and senesces easily. In the present study, freshly harvested broccoli was treated with selenite and stored at two different temperatures. The effect of selenite treatment on sensory quality and postharvest physiology were analyzed. Volatile components were assessed by HS-SPME combined with GC-MS and EN. The metabolism of Se and S was also examined. Results indicated that Se treatment had a significant effect on maintaining the sensory quality, suppressing the respiration intensity and ethylene production, as well as increasing the content of Se and decreasing the content of S. In particular, significant differences in the composition of volatile compounds were present between control and Se-treated. The differences were mainly due to differences in alcohols and sulfide compounds. These results demonstrate that Se treatment can have a positive effect on maintaining quality and enhancing its sensory quality through the release of volatile compounds. PMID:27596413

  16. Effects of some metallic compounds on Klebsiella

    SciTech Connect

    Wong, S.H.

    1988-04-01

    Many industrial and waste disposal practices unconsciously pollute the environment by adding excess heavy metals to it. Although reports show an inconsistency in the toxic levels of heavy metals such as zinc, nickel, cadmium, mercury and silvery between microbial groups, the toxic effects of the metals on microorganisms have been well documented. Little is known of the differential effects these metals have on coliform K. pneumoniae and K. oxytoca. These bacteria are widely recognized as antibiotic resistant opportunistic pathogens. Besides, they are able to fix dinitrogen. In this study, these metals were found to affect these organisms in a variety of concentrations. Such effect could affect the total coliform count in water, dinitrogen fixation, and removable of nitrate in soil and water.

  17. Effects of some metallic compounds on Klebsiella

    SciTech Connect

    Wong, S.H. )

    1988-05-01

    Many industrial and waste disposal practices unconsciously pollute the environment by adding excess heavy metals to it. Although reports show an inconsistency in the toxic levels of heavy metals such as zinc, nickel, cadmium, mercury and silver between microbial groups, the toxic effects of the metals on microorganisms have been well documented. Little is known of the differential effects these metals have on coliform K. pneumoniae and K. oxytoca. These bacteria are widely recognized as antibiotic resistant opportunistic pathogens ubiquitously distributed in environments. Besides, they are able to fix dinitrogen. In this study, these metals were found to affect these organisms in a variety of concentrations. Such effect could affect the total coliform count in water, dinitrogen fixation, and removable of nitrate in soil and water.

  18. Determination of migration pathways of DNAPL and dissolved phase volatile organic compounds in heterogeneous aquifer systems

    SciTech Connect

    Lamb, B. ); Prucha, R.

    1993-10-01

    Before an effective ground-water extraction system can be designed, it is essential to determine the distribution of chemicals of concern in ground-water and preferential pathways for chemical migration. At the study site, determining the chemical migration pathways and spatial distribution of chemicals are complicated by the presence of halogenated volatile organic compounds (VOCs) and dense nonaqueous phase liquids (DNAPL) coupled with the heterogeneous nature of the aquifer. DNAPL is denser than ground water and therefore sinks due to gravity while the dissolved components tend to be dominated by regional ground-water advective flow. The study area is a former industrial site. The aquifer is a low permeability unit with thin lenses of sandy material. Dissolved phase chemicals preferentially migrate in these sand units. To determine pathways for the migration of chemicals both laterally and horizontally, borehole lithologic data, hydraulic data, and chemical data were synthesized into a computer database and used as input for graphical illustrations using computer aided drafting (CAD). The CAD software was also used to provide the basis for 2-D and 3-D visualization to interpret field data which aided in development of a detailed conceptual site model and in construction of a numerical ground-water flow model for the site.

  19. Determination of volatile organic compounds for a systematic evaluation of third-hand smoking.

    PubMed

    Ueta, Ikuo; Saito, Yoshihiro; Teraoka, Kenta; Miura, Tomoya; Jinno, Kiyokatsu

    2010-01-01

    Third-hand smoking was quantitatively evaluated with a polymer-packed sample preparation needle and subsequent gas chromatography-mass spectroscopy analysis. The extraction needle was prepared with polymeric particles as the extraction medium, and successful extraction of typical gaseous volatile organic compounds (VOCs) was accomplished with the extraction needle. For an evaluation of this new cigarette hazard, several types of clothing fabrics were exposed to sidestream smoke, and the smoking-related VOCs evaporated from the fabrics to the environmental air were preconcentrated with the extraction needle. Smoking-related VOCs in smokers' breath were also measured using the extraction needle, and the effect of the breath VOCs on third-hand smoking pollution was evaluated. The results demonstrated that a trace amount of smoking-related VOCs was successfully determined by the proposed method. The adsorption and desorption behaviors of smoking-related VOCs were clearly different for each fabric material, and the time variations of these VOCs concentrations were quantitatively evaluated. The VOCs in the smokers' breath were clearly higher than that of nonsmokers'; however, the results suggested that no significant effect of the smokers' breath on the potential pollution occurred in the typical life space. The method was further applied to the determination of the actual third-hand smoking pollution in an automobile, and a future possibility of the proposed method to the analysis of trace amounts of VOCs in environmental air samples was suggested. PMID:20467132

  20. Dicyclohexylcarbodiimide as a cleaving agent for colorimetric determination of pyridyl and pyrimidinyl compounds

    SciTech Connect

    Chen, S.C.

    1985-06-01

    By use of dicyclohexylcarbodiimide (DCC) and dimethylbarbituric acid (DMBA) as reagents, a colorimetric method for the determination of pyridyl and pyrimidinyl compounds has been established. DCC breaks the pyridine or pyrimidine ring to afford glutaconaldehyde or malonaldehyde and then reacts with DMBA to produce chromophores. These heterocycles could be determined by measuring the chromophores. The relative standard deviations obtained with different amounts of these compounds were in a range of 0.63 to 5.36% (n = 10). The reaction mechanism is also discussed. 22 references, 4 figures, 1 table.

  1. Determination of n-butylated trialkyllead compounds by gas chromatography with microwave plasma emission detection

    SciTech Connect

    Estes, S.A.; Uden, P.C.; Barnes, R.M.

    1982-12-01

    An analytical gas chromatographic procedure is described for the determination of trialkyllead compounds in aqueous media. The analyte compounds are extracted into benzene from an aqueous solution saturated with sodium chloride. They are then quantitatively converted into n-butyltrialkyllead derivatives by reaction with an n-butyl Grignard reagent. Precolumn Tenax trap enrichment of the derived trialkylbutylleads enables determination to low parts per billion levels to be carried out. Also investigated are extraction efficiencies and injection split ratios onto a fused silica capillary column. Lead specific detection is by atmospheric pressure microwave induced plasma spectrometric emission. Data are presented for a wastewater effluent sample. 3 figures.

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

    PubMed

    Sun, Yifei; Watanabe, Nobuhisa; Wang, Wei; Zhu, Tianle

    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 radiofrequency-helium-plasma/atomic emission spectrometry, for the detection of semi- and low-volatile organic halogen compounds (SLVOXs), which can be collected by Carbotrap 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 difficult than measuring C1 or Br, because the wavelength of F is close to that of air. The barrier-discharge 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 200-2300C. Under optimal analysis conditions, a chlorine-containing plastic was destroyed using different oxygen concentrations. Lower oxygen concentrations resulted in the production of lower amounts of organic halogen compounds. PMID:23586317

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

    PubMed

    Sun, Yifei; Watanabe, Nobuhisa; Wang, Wei; Zhu, Tianle

    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 radiofrequency-helium-plasma/atomic emission spectrometry, for the detection of semi- and low-volatile organic halogen compounds (SLVOXs), which can be collected by Carbotrap 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 difficult than measuring C1 or Br, because the wavelength of F is close to that of air. The barrier-discharge 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 200-2300C. Under optimal analysis conditions, a chlorine-containing plastic was destroyed using different oxygen concentrations. Lower oxygen concentrations resulted in the production of lower amounts of organic halogen compounds.

  4. Determination of lipophilicity of chlorinated alicyclic compounds by reversed-phase high performance liquid chromatography

    SciTech Connect

    Liu, J.; Coats, J.R. . Dept. of Entomology); Chambers, J.E. . Coll. of Veterinary Medicine)

    1994-01-01

    A RP-HPLC procedure has been developed for measuring the capacity factor (k[prime]) of a series of chlorinated alicyclic compounds. The chromatographic behavior measured on a 4.5 mm i.d. [times] 3.3 cm C-18 column with methanol/water as the mobile phase was related to the volume fraction of methanol ([phi]). A linear relationship was found between log k[prime] and [phi], showing the correlation coefficient [lambda] > 0.99, for each of the 15 chlorinated alicyclic compounds tested. The log k[sub w], the capacity factor obtained by extrapolation of the retention data from binary effluents to 100% water, was chosen as a measure of the solute lipophilicity. Since log k[sub w] is considered as a valuable index of the lipophilicity of a compound, the determined values will be used for the quantitative structure-activity relationship studies of the chlorinated alicyclic compounds.

  5. Δ9-Tetrahydrocannabinol-like discriminative stimulus effects of compounds commonly found in K2/Spice.

    PubMed

    Gatch, Michael B; Forster, Michael J

    2014-12-01

    A number of cannabinoid compounds are being sold in the form of incense as 'legal' alternatives to marijuana. The purpose of these experiments was to determine whether the most common of these compounds have discriminative stimulus effects similar to Δ-tetrahydrocannabinol (Δ-THC), the main active component in marijuana. Locomotor depressant effects of JWH-018, JWH-073, JWH-200, JWH-203, JWH-250, AM-2201, and CP 47,497-C8-homolog were tested in mice. The compounds were then tested for substitution in rats trained to discriminate Δ-THC (3 mg/kg, intraperitoneally). The time course of the peak dose of each compound was also tested. Each of the synthetic cannabinoids dose-dependently decreased locomotor activity for 1-2 h. Each of the compounds fully substituted for the discriminative stimulus effects of Δ-THC, mostly at doses that produced only marginal amounts of rate suppression. JWH-250 and CP 47,497-C8-homolog suppressed response rates at doses that fully substituted for Δ-THC. The time courses varied markedly between compounds. Most of the compounds had a shorter onset than Δ-THC, and the effects of three of the compounds lasted substantially longer (JWH-073, JWH-250, and CP 47,497-C8-homolog). Several of the most commonly used synthetic cannabinoids produce behavioral effects comparable with those of Δ-THC, which suggests that these compounds may share the psychoactive effects of marijuana responsible for abuse liability. The extremely long time course of the discriminative stimulus effects and adverse effects of CP 47,497-C8-homolog suggest that CP 47,497-C8-homolog may be associated with increased hazards among humans.

  6. Δ9-Tetrahydrocannabinol-like discriminative stimulus effects of compounds commonly found in K2/Spice.

    PubMed

    Gatch, Michael B; Forster, Michael J

    2014-12-01

    A number of cannabinoid compounds are being sold in the form of incense as 'legal' alternatives to marijuana. The purpose of these experiments was to determine whether the most common of these compounds have discriminative stimulus effects similar to Δ-tetrahydrocannabinol (Δ-THC), the main active component in marijuana. Locomotor depressant effects of JWH-018, JWH-073, JWH-200, JWH-203, JWH-250, AM-2201, and CP 47,497-C8-homolog were tested in mice. The compounds were then tested for substitution in rats trained to discriminate Δ-THC (3 mg/kg, intraperitoneally). The time course of the peak dose of each compound was also tested. Each of the synthetic cannabinoids dose-dependently decreased locomotor activity for 1-2 h. Each of the compounds fully substituted for the discriminative stimulus effects of Δ-THC, mostly at doses that produced only marginal amounts of rate suppression. JWH-250 and CP 47,497-C8-homolog suppressed response rates at doses that fully substituted for Δ-THC. The time courses varied markedly between compounds. Most of the compounds had a shorter onset than Δ-THC, and the effects of three of the compounds lasted substantially longer (JWH-073, JWH-250, and CP 47,497-C8-homolog). Several of the most commonly used synthetic cannabinoids produce behavioral effects comparable with those of Δ-THC, which suggests that these compounds may share the psychoactive effects of marijuana responsible for abuse liability. The extremely long time course of the discriminative stimulus effects and adverse effects of CP 47,497-C8-homolog suggest that CP 47,497-C8-homolog may be associated with increased hazards among humans. PMID:25325289

  7. Irradiation effects on polymer-model compounds

    NASA Astrophysics Data System (ADS)

    Seguchi, Tadao; Katsumura, Yosuke; Hayashi, Nariyuki; Hayakawa, Naohiro; Tamura, Naoyuki; Tabata, Yoneho

    Irradiation effects on n-paraffins and squalane, used as models of polymers, were investigated by product analysis. Four n-paraffins, C 20H 42, C 21H 44, C 23H 48 and C 24H 50, and squalane (C 30H 62) were γ-irradiated under vacuum in liquid, crystalline and glassy states. The evolved gases were analyzed by gas chromatography and changes in molecular weight were analyzed by liquid chromatography and mass spectroscopy. G-values for crosslinking of n-paraffins were 1.2 for crystalline states (at 25°C) and 1.7 for liquid states (at 55°C), and showed no difference between odd and even carbon numbers. The G-value of liquid squalane was 1.7; it was 1.3 for the glassy state at low temperature (-77°C). Double bonds were common in the crosslinked products, especially after liquid-phase irradiation. The probability of chain scission was estimated as being negligible, though a small number of chain-scission products (which were products of scission at chain-ends or side chains) were observed by gas analysis.

  8. Biomedical effects of mushrooms with emphasis on pure compounds.

    PubMed

    Paterson, R Russell M; Lima, Nelson

    2014-01-01

    Medicinal mushrooms show great promise for disease treatments. They have been employed in the Orient and Occident for thousands of years, although the practice has persisted in the East. They remain highly valuable. Authentic human trials and pure compounds are emphasized in this review of the most current literature. Polysaccharides from the fungi appear effective in cancer treatments and low-molecular-weight compounds also attract much interest. However, reports of toxicity must be taken seriously. Prescriptions for mushrooms and preparations need to be given by qualified medical practitioners. The reason why these preparations are not more widely used in the West is related to problems of (A) intellectual property rights, (B) mass production, and (C) obtaining pure compounds that retain activity. Mushroom compounds require testing against infectious diseases such as those caused by bacteria, because the current antibiotics are failing from resistances. Overall, the future is assured for medicinal mushrooms.

  9. Simultaneous determination of eight biologically active thiol compounds using gradient elution-liquid chromatography with Coul-Array detection.

    PubMed

    Petrlova, Jitka; Mikelova, Radka; Stejskal, Karel; Kleckerova, Andrea; Zitka, Ondrej; Petrek, Jiri; Havel, Ladislav; Zehnalek, Josef; Vojtech, Adam; Trnkova, Libuse; Kizek, Rene

    2006-05-01

    The most active form of sulfur in biomolecules is the thiol group, present in a number of biologically active compounds. Here we present a comprehensive study of thiol analysis using flow injection analysis/HPLC with electrochemical detection. The effect of different potentials of working electrodes, of organic solvent contents in the mobile phase, and of isocratic and gradient elution on simultaneous determination of thiol compounds (cysteine, cystine, N-acetylcysteine, homocysteine, reduced and oxidised glutathione, desglycinephytochelatin, and phytochelatins) are described and discussed. These thiol compounds were well separated and detected under optimised HPLC-electrochemical detection conditions (mobile phase: 80 mM trifluoroacetic acid and methanol with a gradient profile starting at 97:3 (TFA:methanol), kept constant for the first 8 min, then decreasing to 85:15 during one minute, kept constant for 8 min, and finally increasing linearly up to 97:3 from 17 to 18 min; the flow rate was 0.8 mL/min, column and detector temperature 25 degrees C, and the electrode potential 900 mV). We were able to determine tens of femtomoles (3 S/N) of the thiols per injection (5 microL), except for phytochelatin5 whose detection limit was 2.1 pmole. This technique was consequently used for simultaneous determination of compounds of interest in biological samples (maize tissue and human blood serum). PMID:16830732

  10. Ab initio determination of dark structures in radiationless transitions for aromatic carbonyl compounds.

    PubMed

    Fang, Wei-Hai

    2008-03-01

    Mechanistic photodissociation of a polyatomic molecule has long been regarded as an intellectually challenging area of chemical physics, the results of which are relevant to atmospheric chemistry, biological systems, and many application fields. Carbonyl compounds play a unique role in the development of our understanding of the spectroscopy, photochemistry, and photophysics of polyatomic molecules and their photodissociation has been the subject of numerous studies over many decades. Upon irradiation, a molecule can undergo internal conversion (IC) and intersystem crossing (ISC) processes, besides photochemical and other photophysical processes. Transient intermediates formed in the IC and ISC radiationless processes, which are termed "dark", are not amenable to detection by conventional light absorption or emission. However, these dark intermediates play critical roles in IC and ISC processes and thus are essential to understanding mechanistic photochemistry of a polyatomic molecule. We have applied the multiconfiguration complete active space self-consistent field (CASSCF) method to determine the dark transient structures involved in radiationless processes for acetophenone and the related aromatic carbonyl compounds. The electronic and geometric structures predicted for the dark states are in a good agreement with those determined by ultrafast electron diffraction experiments. Intersection structure of different electronic states provides a very efficient "funnel" for the IC or ISC process. However, experimental determination of the intersection structure involved in radiationless transitions of a polyatomic molecule is impossible at present. We have discovered a minimum energy crossing point among the three potential energy surfaces (S1, T1, and T2) that appears to be common to a wide variety of aromatic carbonyl compounds with a constant structure. This new type of crossing point holds the key to understanding much about radiationless processes after

  11. Using a Disposable Pipet for Preparing Air-Sensitive Compounds for Melting Point Determinations or Storage

    ERIC Educational Resources Information Center

    Sanz, Martial

    2004-01-01

    A thin-wall disposable Pasteur pipet is used as a vacuum-tight receptacle for air-sensitive compounds to ascertain their melting points. This technique is easy, economical, and successfully used for many years to develop air-sensitive samples for melting point determinations.

  12. Analytical determination of bioactive compounds as an indication of fruit quality.

    PubMed

    Park, Yong Seo; Heo, Buk-Gu; Ham, Kyung-Sik; Kang, Seong-Gook; Park, Yang-Kyun; Nemirovski, Alina; Tashma, Zeev; Gorinstein, Shela; Leontowicz, Hanna; Leontowicz, Maria

    2012-01-01

    The aim of this investigation was to determine the bioactive compounds in kiwifruit as an indication of quality after extraction using methanol and ethyl acetate. Using FTIR and three-dimensional fluorescence spectroscopy and electrospray ionization/MS, the contents of polyphenols, flavonoids, flavanols, and tannins, and the level of the antioxidant activity by 2, 2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt, 1, 1-diphenyl-2-picrylhydrazyl, ferric-reducing/ antioxidant power, and cupric reducing antioxidant capacity assays were determined and compared. It was found that the methanol extracts of kiwifruit showed significantly higher amounts of bioactive acetate extracts. The cultivar Bidan, in comparison compounds and antioxidant activities than the ethyl with the classic Hayward, showed significantly higher bioactivity. For the first time, Bidan organic kiwifruit was analyzed for its antioxidant activities and compared with the widely consumed Hayward organic based on its bioactive compounds and fluorescence properties. Relatively high content of bioactive compounds and positive antioxidant and antiproliferative properties of kiwifruit determined by the advanced analytical methods justify its use as a source of valuable antioxidants. The methods used are applicable for bioactivity determination, in general, for any food products.

  13. SEPARATION AND ISOLATION OF VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION WITH GC/MS DETERMINATION

    EPA Science Inventory

    Vacuum distillation of water, soil, oil, and fish samples is presented as an alternative technique for determining volatile organic compounds (VOCs). Analyses of samples containing VOCs and non-VOCs at 50ppb concentrations were performed to evaluate method limitations. Analyte re...

  14. Screening cosmetic products for N-nitroso compounds by chemiluminescent determination of nitric oxide.

    PubMed

    Chou, H J; Yates, R L; Wenninger, J A

    1987-01-01

    Cosmetic products were screened for total N-nitroso compounds by chemiluminescent measurement of nitric oxide liberated by the reductive cleavage of the N-nitroso group. The cosmetic was first partitioned between methylene chloride and water to separate polar and nonpolar N-nitroso compounds. Each extract was then examined for the presence of N-nitroso compounds by adding the cleavage reagent and sweeping the nitric oxide formed into a chemiluminescent analyzer. Although the method is not intended to be quantitative, recovery studies were conducted to determine measurable levels. Recovery studies of polar N-nitroso compounds were conducted by adding N-nitrosodiethanolamine (NDELA) to a cream, a shampoo, and a lotion at 3 levels, i.e., 80, 320, and 960 ppb, and then determining NDELA by the method. Recoveries ranged from 48 to 83% (mean 68%; SD = 11.9). For recoveries of nonpolar N-nitroso compounds, 100, 200, and 500 ppb of N-nitrosomethyltetradecylamine were added to the 3 cosmetic products. Recoveries ranged from 58 to 70% (mean 63%; SD = 5.3).

  15. Effects of perfluorinated compounds on development of zebrafish embryos.

    PubMed

    Zheng, Xin-Mei; Liu, Hong-Ling; Shi, Wei; Wei, Si; Giesy, John P; Yu, Hong-Xia

    2011-08-01

    Perfluorinated compounds (PFCs) have been widely used in industrial and consumer products and frequently detected in many environmental media. Potential reproductive effects of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) have been reported in mice, rats and water birds. PFOS and PFOA were also confirmed developing toxicants towards zebrafish embryos; however, the reported effect concentrations were contradictory. Polyfluorinated alkylated phosphate ester surfactants (including FC807) are precursor of PFOS and PFOA; however, there is no published information about the effects of FC807 and PFNA on zebrafish embryos. Therefore, this study was conducted to determine the effects of these four PFCs on zebrafish embryos. Normal fertilized zebrafish embryos were selected to be exposed to several concentrations of PFOA, PFNA, PFOS or FC807 in 24-well cell culture plates. A digital camera was used to image morphological anomalies of embryos with a stereomicroscope. Embryos were observed through matching up to 96-h post-fertilization (hpf) and rates of survival and abnormalities recorded. PFCs caused lethality in a concentration-dependent manner with potential toxicity in the order of PFOS > FC807 > PFNA > PFOA based on 72-h LC(50). Forty-eight-hour post-fertilization pericardial edema and 72- or 96-hpf spine crooked malformation were all observed. PFOA, PFNA, PFOS and FC807 all caused structural abnormalities using early stages of development of zebrafish. The PFCs all retarded the development of zebrafish embryos. The toxicity of the PFCs was related to the length of the PFC chain and functional groups. PMID:22828880

  16. Nephrotoxic and hepatotoxic effects of chromium compounds in rats

    SciTech Connect

    Laborda, R.; Diaz-Mayans, J.; Nunez, A.

    1986-03-01

    The nephrotoxic, hepatotoxic and cardiotoxic actions of hexavalent chromium compounds, as well as their effects on lung, blood and circulation may contribute to the fatal outcome of chromium intoxication. Although trivalent chromium have been regarded as relatively biologically inert, there are a few salts of chromium III that have been found to be carcinogenic when inhaled, ingested or brought in contact with the tissues. Sensitive persons and industry workers have been subjects of dermatitis, respiratory tract injuries and digestive ulcers due to chromium compounds. In this work, the authors have studied the effect of trivalent and hexavalent chromium compounds on rats measuring the transaminases (GOT and GPT), urea and creatinine levels in serum of chromium poisoned animals at different times.

  17. Determination of nonylphenol ethoxylates and octylphenol ethoxylates in environmental samples using 13C-labeled surrogate compounds.

    PubMed

    Yoshida, Yasuko; Ito, Azusa; Murakami, Masashi; Murakami, Takayuki; Fujimoto, Hideharu; Takeda, Kikuo; Suzuki, Shigeru; Hori, Masahiro

    2007-10-01

    Alkylphenol polyethoxylates (APEOs) have been widely used as nonionic surfactants in a variety of industrial and commercial products. Typical compounds are nonylphenol polyethoxylates (NPEOs) and octylphenol polyethoxylates (OPEOs), which serve as precursors to nonylphenol (NP) and octylphenol (OP), respectively. NP and 4-t-OP are known to have endocrine disrupting effects on fish (medaka, Oryzias latipes), so it is important to know the concentrations of APEOs in the environment. Because the analytical characteristics of these compounds depend on the length of the ethoxy chain, it is necessary to use appropriate compounds as internal standards or surrogates. We synthesized two 13C-labeled surrogate compounds and used these compounds as internal standards to determine NPEOs and OPEOs by high-performance liquid chromatography (LC)-mass spectrometry. Method detection limits were 0.015 microg/L for NP (2)EO to 0.037 microg/L for NP(12)EO, and 0.011 microg/L for OP(3,6)EO to 0.024 microg/L for OP (4)EO. NPEO concentrations in water from a sewage treatment plant were less than 0.05-0.52 microg/L for final effluent and 1.2-15 microg/L for influent. OPEO concentrations were less than 0.05-0.15 microg/L for the final effluent and less than 0.05-1.1 microg/L for influent. PMID:17972761

  18. Metabolism and effects of organic compounds in animals

    SciTech Connect

    Eisele, G.R.

    1985-10-01

    The knowledge of the metabolism and effects of organic compounds in animals, specifically food-producing animals, are of paramount importance in assessing potential human health hazards. An intensive effort has been directed at detection of chemicals in the environment, determination of their physiological insult and cellular interaction; in particular their carcinogenic and mutagenic induction capability. The chemical exposure of food-producing animals can be extremely difficult to evaluate and quite devastating. The exposure of food-producing animals to polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) emphasizes the seriousness of the problem. The polycyclic aromatic hydrocarbons (PAHs), capable of inducing cancer in experimental animals, have been studied extensively in laboratory animals. Current studies deal with the mechanism of metabolism of PAHs and the ultimate carcinogenic form. Although our knowledge concerning the health hazards of organic chemicals is continually increasing, its impact on food-producing animals and man's food chain is poorly understood. Awareness of the problem by practicing veterinarians and toxicologists, environmental toxicologists and public health officials is required to evaluate the impact of organic chemicals on the human food chain. 6 references.

  19. Δ9-Tetrahydrocannabinol-Like Discriminative Stimulus Effects of Compounds Commonly Found in K2/Spice

    PubMed Central

    Gatch, Michael B.; Forster, Michael J.

    2014-01-01

    A number of cannabinoid compounds are being sold in the form of incense as “legal” alternatives to marijuana. The purpose of these experiments was to determine whether the most common of these compounds have discriminative stimulus effects similar to Δ9-tetrahydrocannabinol, the main active component in marijuana. Locomotor depressant effects of JWH-018, JWH-073, JWH-200, JWH-203, JWH-250, AM-2201 and CP 47,497-C8-homolog were tested in mice. The compounds were then tested for substitution in rats trained to discriminate Δ9-tetrahydrocannabinol (3 mg/kg, i.p.). The time course of the peak dose of each compound was also tested. Each of the synthetic cannabinoids dose-dependently decreased locomotor activity for one to two hours. Each of the compounds fully substituted for the discriminative stimulus effects of Δ9-tetrahydrocannabinol, mostly at doses that produced only marginal amounts of rate suppression. JWH-250 and CP 47,497-C8-homolog suppressed response rates at doses that fully substituted for Δ9-THC. The time courses varied markedly between compounds. Most of the compounds had a shorter onset than Δ9-THC, and three lasted substantially longer (JWH-073, JWH-250 and CP 47,497-C8-homolog). Several of the most commonly used synthetic cannabinoids produce behavioral effects comparable to those of Δ9-tetrahydrocannabinol, which suggests that these compounds may share the psychoactive effects of marijuana responsible for abuse liability. The extremely long time course of the discriminative stimulus effects and adverse effects of CP 47,497-C8-homolog suggest that CP 47,497-C8-homolog may be associated with increased hazards in humans. PMID:25325289

  20. [Determination of volatile organic compounds in blood by headspace solid-phase microextraction-gas chromatography].

    PubMed

    Hao, S; Kang, J; Zhou, S; Cui, J

    2000-01-30

    The headspace solid-phase microextraction (HS-SPME) is a novel extraction technique and has been developed rapidly. It is a fast, simple, solventless and sensitive method for sampling, separating, extracting, injecting and analyzing volatile organic compounds. This paper presents the research work in detecting volatile organic compounds(including ten compounds) in blood. The extraction fiber is made by fused-silica fiber with 100 microns polydimethylsiloxane (PDMS). The extraction time of the method was 10 min. The thermal desorption time was 1 min. It was found that the optimized location of the extraction fiber in the injector of GC was to put the whole needle in the injector. The precision of the method was determined to be less 5% relative standard deviation (RSD). The linear range of the detection was rather wide. The lowest detectin limits (LODs) were all < or = 5 ng/ml.

  1. Retrospective Revaluation Effects Following Serial Compound Training and Target Extinction

    ERIC Educational Resources Information Center

    Effting, Marieke; Vervliet, Bram; Kindt, Merel

    2010-01-01

    Using a conditioned suppression task, two experiments examined retrospective revaluation effects after serial compound training in a release from overshadowing design. In Experiment 1, serial X [right arrow] A+ training produced suppression to target A, which was enhanced when preceded by feature X, whereas X by itself elicited no suppression.…

  2. Determining Source Strength of Semivolatile Organic Compounds using Measured Concentrations in Indoor Dust

    PubMed Central

    Shin, Hyeong-Moo; McKone, Thomas E.; Nishioka, Marcia G.; Fallin, M. Daniele; Croen, Lisa A.; Hertz-Picciotto, Irva; Newschaffer, Craig J.; Bennett, Deborah H.

    2014-01-01

    Consumer products and building materials emit a number of semivolatile organic compounds (SVOCs) in the indoor environment. Because indoor SVOCs accumulate in dust, we explore the use of dust to determine source strength and report here on analysis of dust samples collected in 30 U.S. homes for six phthalates, four personal care product ingredients, and five flame retardants. We then use a fugacity-based indoor mass-balance model to estimate the whole house emission rates of SVOCs that would account for the measured dust concentrations. Di-2-ethylhexyl phthalate (DEHP) and di-iso-nonyl phthalate (DiNP) were the most abundant compounds in these dust samples. On the other hand, the estimated emission rate of diethyl phthalate (DEP) is the largest among phthalates, although its dust concentration is over two orders of magnitude smaller than DEHP and DiNP. The magnitude of the estimated emission rate that corresponds to the measured dust concentration is found to be inversely correlated with the vapor pressure of the compound, indicating that dust concentrations alone cannot be used to determine which compounds have the greatest emission rates. The combined dust-assay modeling approach shows promise for estimating indoor emission rates for SVOCs. PMID:24118221

  3. Simultaneous Determination of Matrine and Tinidazole in Compound Lotion by RH-HPLC Method.

    PubMed

    Yin, Zhikui; Ma, Suying; Wang, Jincai; Shang, Xiaojun

    2013-01-01

    A simple, sensitive, and accurate RP-HPLC coupled with UV detector method was developed and validated for simultaneous determination of matrine and tinidazole in compound lotion. The chromatographic separation of the two compounds was carried out with a SinoChoom ODS-BP C18 column (5  μ m, 4.6 mm × 200 mm) analytical column, using a mobile phase consisting of 0.025 mol/L potassium dihydrogen phosphate (containing triethylamine 0.05%, v/v) and acetonitrile (80 : 20, v/v) at a flow rate of 1.0 mL/min. The detection was monitored at 210 and 310 nm for matrine and tinidazole, respectively. Total run time was 12 min, and the column was maintained at 25°C. The excipients in the compound lotion did not interfere with the drug peaks. The calibration curves of matrine and tinidazole were fairly linear over the concentration ranges of 10.0-100.0  μ g/mL (r = 0.9954) and 20.0-200.0  μ g/mL (r = 0.9968), respectively. The RSD of both the intraday and interday variations was below 1.5% for matrine and tinidazole. The proposed HPLC method was validated according to International Conference on Harmonisation and proved to be suitable for the simultaneous determination of matrine and tinidazole in compound lotion.

  4. The effect of high pressure on nitrogen compounds of milk

    NASA Astrophysics Data System (ADS)

    Kielczewska, Katarzyna; Czerniewicz, Maria; Michalak, Joanna; Brandt, Waldemar

    2004-04-01

    The effect of pressurization at different pressures (from 200 to 1000 MPa, at 200 MPa intervals, tconst. = 15 min) and periods of time (from 15 to 35 min, at 10 min intervals, pconst. = 800 MPa) on the changes of proteins and nitrogen compounds of skimmed milk was studied. The pressurization caused an increase in the amount of soluble casein and denaturation of whey proteins. The level of nonprotein nitrogen compounds and proteoso-peptone nitrogen compounds increased as a result of the high-pressure treatment. These changes increased with an increase in pressure and exposure time. High-pressure treatment considerably affected the changes in the conformation of milk proteins, which was reflected in the changes in the content of proteins sedimenting and an increase in their degree of hydration.

  5. Limits of rapid log P determination methods for highly lipophilic and flexible compounds.

    PubMed

    Martel, Sophie; Begnaud, Frédéric; Schuler, William; Gillerat, Fabrice; Oberhauser, Nils; Nurisso, Alessandra; Carrupt, Pierre-Alain

    2016-04-01

    Lipophilicity is of crucial importance in many fields including pharmaceutical, environmental, cosmetic and food industries. Whereas different experimental strategies have been developed for rapid lipophilicity determination of new chemical entities, log P determination of highly lipophilic compounds is always challenging. In this study, three published chromatographic methods have been compared on a series of phenylalkanoic acids including the pro-perfume HaloscentD (HD-C12). Different log P values were obtained depending on the chromatographic method used for log P estimation. Molecular modelling suggested that log P variations may be due to the chromatographic conditions applied (isocratic or gradient mode, ratio methanol/water in the mobile phase), responsible of specific conformations of the molecule in solution. Thus, for flexible compounds, published methods have to be used with caution and considered as a good tool to estimate a log P range, depending on the molecular conformational state.

  6. Limits of rapid log P determination methods for highly lipophilic and flexible compounds.

    PubMed

    Martel, Sophie; Begnaud, Frédéric; Schuler, William; Gillerat, Fabrice; Oberhauser, Nils; Nurisso, Alessandra; Carrupt, Pierre-Alain

    2016-04-01

    Lipophilicity is of crucial importance in many fields including pharmaceutical, environmental, cosmetic and food industries. Whereas different experimental strategies have been developed for rapid lipophilicity determination of new chemical entities, log P determination of highly lipophilic compounds is always challenging. In this study, three published chromatographic methods have been compared on a series of phenylalkanoic acids including the pro-perfume HaloscentD (HD-C12). Different log P values were obtained depending on the chromatographic method used for log P estimation. Molecular modelling suggested that log P variations may be due to the chromatographic conditions applied (isocratic or gradient mode, ratio methanol/water in the mobile phase), responsible of specific conformations of the molecule in solution. Thus, for flexible compounds, published methods have to be used with caution and considered as a good tool to estimate a log P range, depending on the molecular conformational state. PMID:26995644

  7. First structural determination of a trivalent californium compound with oxygen coordination.

    PubMed

    Sykora, Richard E; Assefa, Zerihun; Haire, Richard G; Albrecht-Schmitt, Thomas E

    2006-01-23

    Single crystals of Cf(IO(3))(3) (1) were synthesized by the hydrothermal reaction of CfCl(3) and H(5)IO(6), and the structure was determined with single-crystal X-ray diffraction. This structural determination of 1 represents the first for a trivalent californium compound containing oxygen coordination. This compound has been further characterized with the use of Raman spectroscopy and emission spectroscopy. Crystallographic data: Cf(IO(3))(3), monoclinic, space group P2(1)/n, a = 8.7994(10) A, b = 5.9388(7) A, c = 15.157(2) A, beta = 96.833(2) degrees , V = 786.43(16) A(3), Z = 4 (T = 295 K).

  8. Determination of total polyphenolic compounds and flavonoids in Juglans regia leaves.

    PubMed

    Qureshi, Muhammad Nasimullah; Stecher, Guenther; Bonn, Guenther Karl

    2014-07-01

    Juglans regia leaves have been widely used in traditional medicines because of its antimicrobial, antihelmintic, astringent, keratolytic, antidiarrhoeal, hypoglycaemic, depurative, tonic, carminative activity. Total polyphenolic compounds were determined using the Folin-Ciocalteau method and flavonoids were quantified using the HPLC-PDA after the hydrolysis of the plant material with HCl. Among the flavonoids myricetin, quercetin, apigenin and kaempferol were found in appreciable amount.

  9. Determination of acid-base dissociation constants of amino- and guanidinopurine nucleotide analogs and related compounds by capillary zone electrophoresis.

    PubMed

    Solínová, Veronika; Kasicka, Václav; Koval, Dusan; Cesnek, Michal; Holý, Antonín

    2006-03-01

    CZE has been applied for determination of acid-base dissociation constants (pKa) of ionogenic groups of newly synthesized amino- and (amino)guanidinopurine nucleotide analogs, such as acyclic nucleoside phosphonate, acyclic nucleoside phosphonate diesters and other related compounds. These compounds bear characteristic pharmacophores contained in various important biologically active substances, such as cytostatics and antivirals. The pKa values of ionogenic groups of the above compounds were determined by nonlinear regression analysis of the experimentally measured pH dependence of their effective electrophoretic mobilities. The effective mobilities were measured by CZE performed in series of BGEs in a broad pH range (3.50-11.25), at constant ionic strength (25 mM) and temperature (25 degrees C). pKa values were determined for the protonated guanidinyl group in (amino)guanidino 9-alkylpurines and in (amino)guanidinopurine nucleotide analogs, such as acyclic nucleoside phosphonates and acyclic nucleoside phosphonate diesters, for phosphonic acid to the second dissociation degree (-2) in acyclic nucleoside phosphonates of amino and (amino)guanidino 9-alkylpurines, and for protonated nitrogen in position 1 (N1) of purine moiety in acyclic nucleoside phosphonates of amino 9-alkylpurines. Thermodynamic pKa of protonated guanidinyl group was estimated to be in the range of 7.75-10.32, pKa of phosphonic acid to the second dissociation degree achieved values of 6.64-7.46, and pKa of protonated nitrogen in position 1 of purine was in the range of 4.13-4.89, depending on the structure of the analyzed compounds.

  10. Synergistic Antibacterial Effects of Polyphenolic Compounds from Olive Mill Wastewater

    PubMed Central

    Tafesh, Ahmed; Najami, Naim; Jadoun, Jeries; Halahlih, Fares; Riepl, Herbert; Azaizeh, Hassan

    2011-01-01

    Polyphenols or phenolic compounds are groups of secondary metabolites widely distributed in plants and found in olive mill wastewater (OMW). Phenolic compounds as well as OMW extracts were evaluated in vitro for their antimicrobial activity against Gram-positive (Streptococcus pyogenes and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). Most of the tested phenols were not effective against the four bacterial strains when tested as single compounds at concentrations of up to 1000 μg mL−1. Hydroxytyrosol at 400 μg mL−1 caused complete growth inhibition of the four strains. Gallic acid was effective at 200, and 400 μg mL−1 against S. aureus, and S. pyogenes, respectively, but not against the gram negative bacteria. An OMW fraction called AntiSolvent was obtained after the addition of ethanol to the crude OMW. HPLC analysis of AntiSolvent fraction revealed that this fraction contains mainly hydroxytyrosol (10.3%), verbascoside (7.4%), and tyrosol (2.6%). The combinations of AntiSolvent/gallic acid were tested using the low minimal inhibitory concentrations which revealed that 50/100–100/100 μg mL−1 caused complete growth inhibition of the four strains. These results suggest that OMW specific fractions augmented with natural phenolic ingredients may be utilized as a source of bioactive compounds to control pathogenic bacteria. PMID:21647315

  11. Visualizing Compound Distribution during Zebrafish Embryo Development: The Effects of Lipophilicity and DMSO.

    PubMed

    de Koning, Coco; Beekhuijzen, Manon; Tobor-Kapłon, Marysia; de Vries-Buitenweg, Selinda; Schoutsen, Dick; Leeijen, Nico; van de Waart, Beppy; Emmen, Harry

    2015-12-01

    The predictability of the zebrafish embryo model is highly influenced by internal exposure of the embryo/larva. As compound uptake is likely to be influenced by factors such as lipophilicity, solvent use, and chorion presence, this article focuses on investigating their effects on compound distribution within the zebrafish embryo. To visualize compound uptake and distribution, zebrafish embryos were exposed for 96 hr, starting at 4 hr postfertilization, to water-soluble dyes: Schiff's reagent (logP -4.63), Giemsa stain (logP -0.77), Van Gierson stain (logP 1.64), Cresyl fast violet (logP 3.5), Eosine Y (logP 4.8), Sudan III (logP 7.5), and Oil red O (logP 9.81), with and without 1% dimethyl-sulfoxide (DMSO). Three additional compounds were used to analytically determine the uptake and distribution: Acyclovir (logP -1.56), Zidovudine (logP 0.05), and Metoprolol Tartrate Salt (logP 1.8). Examinations were performed every 24 hr. Both methods (visualization and specific analysis) showed that exposure to higher logP values results in higher compound uptake. Specific analysis showed that for lipophilic compounds >90% of compound is taken up by the embryo. For hydrophilic compounds, >90% of compound within the complete egg could not be associated to embryo or chorion and is probably distributed into the perivitelline space. Overall, internal exposure analyses on at least two occasions (i.e., before and after hatching) is crucial for interpretation of zebrafish embryotoxicity data, especially for compounds with extreme logP values. DMSO did not affect exposure when examined with the visualization method, however, this method might be not sensitive enough to draw hard conclusions.

  12. Filtration of water-sediment samples for the determination of organic compounds

    USGS Publications Warehouse

    Sandstrom, Mark W.

    1995-01-01

    This report describes the equipment and procedures used for on-site filtration of surface-water and ground-water samples for determination of organic compounds. Glass-fiber filters and a positive displacement pumping system are suitable for processing most samples for organic analyses. An optional system that uses disposable in-line membrane filters is suitable for a specific gas chromatography/mass spectrometry, selected-ion monitoring analytical method for determination of organonitrogen herbicides. General procedures to minimize contamination of the samples include preparing a clean workspace at the site, selecting appropriate sample-collection materials, and cleaning of the equipment with detergent, tap water, and methanol.

  13. Use of specific bacteria for the determination of mutagenic and carcinogenic compounds

    SciTech Connect

    Miertus, S.; Svorc, J.; Sturdik, E.; Vojtekova, H.

    1987-02-01

    Possibilities of the use Escherichia coli K-12 in the determination of mutagenic compounds have been tested. Analytical parameters, e.g., the range of linearity of the analytical curve, the detection limit and the sensitivity, the accuracy, and the precision of analysis, have been evaluated for a series of nitrofurans. The detection limit is in the range of 10/sup -7/ - 10/sup -5/ mol L/sup -1/. Analyses of real samples (determination of 5-nitro-2-furylacrylic acid in wine and nitrovin in chicken meat) have been completed without any preseparation.

  14. LC determination of octreotide acetate in compound formulations of Sandostatin and diamorphine hydrochloride.

    PubMed

    Kyaterekera, N; Tettey, J N; Skellern, G G; Watson, D G; Urie, J; McDade, J R; Fielding, H

    1999-11-01

    The determination of octreotide acetate in compound formulations of Sandostatin and diamorphine hydrochloride by RP-LC is described. Octreotide acetate, diamorphine hydrochloride and their respective degradants, [des-Thr-ol8]-octreotide and 6-O-acetylmorphine, were baseline resolved using a Lichrospher-60 RP-select B column with a mobile phase composition of acetonitrile/phosphate buffer (pH 7.4, 20 mM) (35:65 v/v) with UV detection at 210 nm. The method is simple, selective, precise and suitable for the determination of octreotide acetate in admixture.

  15. A high-performance liquid chromatographic determination of major phenolic compounds in tobacco smoke

    SciTech Connect

    Risner, C.H.; Cash, S.L. )

    1990-05-01

    A high-performance liquid chromatographic (HPLC) method is developed that simultaneously quantifies the dihydroxy compounds hydroquinone, resorcinol, and catechol and the monohydroxy compounds phenol, m + p-cresol and o-cresol in cigarette smoke. Particulate matter samples collected on Cambridge pads and in impingers by conventional trapping techniques are simply (no derivatization required) subjected to reversed-phase gradient liquid chromatography. Samples of both mainstream and sidestream smoke can be analyzed. Selective fluorescence detection is used to monitor the mobile phase effluent, by which these phenolic compounds are detected in the nanogram range. The detector response is linear, overall precision is good, and recoveries are greater than 95 percent. The total run time, excluding extraction, is one hour. The procedure has been applied to tobacco products whose smoke contains varying amounts of these phenols. Kentucky Reference Cigarette 1R4F was found to contain substantially more of these compounds than a new cigarette that heats but does not burn tobacco (New Cigarette). The method is compared with other procedures used to determine phenolics in cigarette smoke.

  16. A new analytical protocol for the determination of 62 endocrine-disrupting compounds in indoor air.

    PubMed

    Laborie, Stéphanie; Moreau-Guigon, Elodie; Alliot, Fabrice; Desportes, Annie; Oziol, Lucie; Chevreuil, Marc

    2016-01-15

    The objective of this study was to develop and validate a new analytical protocol for simultaneous determination of 62 semi-volatile organic compounds in both phases of indoor air. Studied compounds belong to several families: polybrominated diphenyl ethers, polychlorinated biphenyls, hexachlorobenzene, pentachlorobenzene, phthalates, polyaromatic hydrocarbons, parabens, tetrabromobisphenol A, bisphenol A, hexabromocyclododecane, triclosan, alkylphenols, alkylphenol ethoxylates, synthetic musks (galaxolide and tonalide) and pesticides (lindane and cypermethrin). A medium volume sampling system was used to collect simultaneously these endocrine-disrupting compounds (EDCs) from the gaseous and particulate phases. An accelerated solvent extraction method was optimized to obtain all EDCs in a single extract by atmospheric phase. Their extraction from the sorbents and their analysis by liquid and gas chromatography-mass spectrometry (LC/MS/MS, GC/MS and GC/MS/MS) was validated using spiked sorbents (recovery study and analytical uncertainty analysis by fully nested design). The developed protocol achieved low limits of quantification (<0.5ng m(-3)) and low uncertainty values (<5ng m(-3)) for all compounds. Once validated, the method was applied to indoor air samples from four locations (a house, an apartment, a day nursery and an office) and compared to literature to confirm its efficiency. All target EDCs were quantified in the samples and were primarily present in the gaseous phase. The major contaminants found in indoor air were, in descending order, phthalates, synthetic musks, alkylphenols and parabens. PMID:26592587

  17. Determination of potentially bioaccumulating complex mixtures of organochlorine compounds in wastewater: a review.

    PubMed

    Contreras López, M Concepción

    2003-03-01

    Organic chlorine compounds can be persistent environmental contaminants and may be accumulated through the food chain to the aquatic organisms, to fish and humans, depending basically on their hydrophobic properties. Consequently, there is an interest to measure these organic compounds from both the scientific and regulatory communities. The analytical essays have been improved for measuring specific organic chlorine compounds that present the most toxicological potential (polychlorinated biphenyls [PCBs], certain pesticides and dioxins), although they are tedious and time-consuming procedures. The existing tests to measure adsorbable organic halogens (AOX) or extractable organic halogens (EOX) do not distinguish the more hydrophobic organic chlorine matter. The intention of this paper is to make a review of the existing methods to measure the potentially bioaccumulating organochlorine compounds (OCs) from wastewater and propose a methodology to a standardisation procedure for complex mixtures of OCs in wastewater, such as pulp mill effluents. A new method has been proposed for determining the most hydrophobic part of the extractable organic halogens (EOX(fob)), the lowest reported value is 0.6 microg/l, expressed as chloride, and the relative standard deviation at 20 microg/l is 7% on laboratory samples and 30% on real effluents. This new procedure could be a valuable tool to complement environmental risk assessment studies of wastewater discharges. PMID:12605924

  18. Comparison of Different Extraction Methods for the Determination of Essential oils and Related Compounds from Coriander (Coriandrum sativum L.).

    PubMed

    Msaada, Kamel; Taârit, Mouna Ben; Hosni, Karim; Nidhal, Salem; Tammar, Sonia; Bettaieb, Iness; Hammami, Mohamed; Limam, Férid; Marzouk, Brahim

    2012-12-01

    The volatile oil of coriander (Coriandrum sativum L.) obtained from the fruits by soxhlet-dynamic headspace (S-DHS), solvent extraction (SE), steam distillation (SD), hydrodistillation (HYD) and supercritical CO2 extraction (SC-CO2) were analyzed by GC-FID and GC-MS. The SC-CO2 offered a higher yield (4.5%, w/w) than the other used techniques. Among the identified constituents, linalool was the main compound whatever the employed extraction procedure in contrast to the remaining components which varied according to the isolation technique showing a strong effect of the method used on the composition of these minor compounds. SC-CO2 as compared to the other extraction techniques revealed its high efficiency in addition to the integrity saving of coriander fruit volatiles. Statistical analysis showed that all the detected and identified compounds were highly (P > 0.001) affected by the extraction technique used except the a-terpineol which appear stable. On the other hand, principal component analysis (PCA) revealed on the determination of one group represented by SC-CO2, S-DHS and HYD suggesting a similar essential oil composition. Obtained results show that, in Tunisian coriander essential oil, linalool was the main compound.

  19. Applicability of solid-phase microextraction combined with gas chromatography atomic emission detection (GC-MIP AED) for the determination of butyltin compounds in sediment samples.

    PubMed

    Carpinteiro, J; Rodríguez, I; Cela, R

    2004-11-01

    The performance of solid-phase microextraction (SPME) applied to the determination of butyltin compounds in sediment samples is systematically evaluated. Matrix effects and influence of blank signals on the detection limits of the method are studied in detail. The interval of linear response is also evaluated in order to assess the applicability of the method to sediments polluted with butyltin compounds over a large range of concentrations. Advantages and drawbacks of including an SPME step, instead of the classic liquid-liquid extraction of the derivatized analytes, in the determination of butyltin compounds in sediment samples are considered in terms of achieved detection limits and experimental effort. Analytes were extracted from the samples by sonication using glacial acetic acid. An aliquot of the centrifuged extract was placed on a vial where compounds were ethylated and concentrated on a PDMS fiber using the headspace mode. Determinations were carried out using GC-MIP AED. PMID:15365677

  20. Effects of germination on the nutritive value and bioactive compounds of brown rice breads.

    PubMed

    Cornejo, Fabiola; Caceres, Patricio J; Martínez-Villaluenga, Cristina; Rosell, Cristina M; Frias, Juana

    2015-04-15

    The effect of germination conditions on the nutritional benefits of germinated brown rice flour (GBR) bread has been determined. The proximate composition, phytic acid, in vitro protein digestibility and in vitro enzymatic hydrolysis of starch, glucose and starch content, as well as the most relevant bioactive compounds (GABA, γ-oryzanol and total phenolic compounds) and antioxidant activity of breads prepared with GBR at different germination conditions was determined. When comparing different germination times (0 h, 12 h, 24 h and 48 h), germination for 48 h provides GBR bread with nutritionally superior quality on the basis of its higher content of protein, lipids and bioactive compounds (GABA and polyphenols), increased antioxidant activity and reduced phytic acid content and glycaemic index, although a slight decrease in in vitro protein digestibility was detected. Overall, germination seems to be a natural and sustainable way to improving the nutritional quality of gluten-free rice breads.

  1. Effects of germination on the nutritive value and bioactive compounds of brown rice breads.

    PubMed

    Cornejo, Fabiola; Caceres, Patricio J; Martínez-Villaluenga, Cristina; Rosell, Cristina M; Frias, Juana

    2015-04-15

    The effect of germination conditions on the nutritional benefits of germinated brown rice flour (GBR) bread has been determined. The proximate composition, phytic acid, in vitro protein digestibility and in vitro enzymatic hydrolysis of starch, glucose and starch content, as well as the most relevant bioactive compounds (GABA, γ-oryzanol and total phenolic compounds) and antioxidant activity of breads prepared with GBR at different germination conditions was determined. When comparing different germination times (0 h, 12 h, 24 h and 48 h), germination for 48 h provides GBR bread with nutritionally superior quality on the basis of its higher content of protein, lipids and bioactive compounds (GABA and polyphenols), increased antioxidant activity and reduced phytic acid content and glycaemic index, although a slight decrease in in vitro protein digestibility was detected. Overall, germination seems to be a natural and sustainable way to improving the nutritional quality of gluten-free rice breads. PMID:25466026

  2. Research in physical chemistry and chemical education: Part A: Water Mediated Chemistry of Oxidized Atmospheric Compounds Part B: The Development of Surveying Tools to Determine How Effective Laboratory Experiments Contribute to Student Conceptual Understanding

    NASA Astrophysics Data System (ADS)

    Maron, Marta Katarzyna

    atmospherically measured oxidized organic molecules and predictions of atmospheric models at different relative humidities. The chemical education portion of this manuscript presented in Chapters VI and VII includes the development of a survey to determine how effective a laboratory experiment is in contributing to students' understanding of fundamental chemistry. The specific example used is an electrochemical cell. Our initial results showed that while most of our students could answer quantitative questions about the operation of the cell, their conceptual understanding of the microscopic processes that occur within the cell was inconsistent with the material presented in class. In particular, we noticed that while many students were able to correctly describe the events that take place at the surface of the anode and cathode, their understanding of the events that take place at the salt bridge was lacking. In this investigation, we were able to confirm the misconceptions reported in previous studies. Our results suggest that a relatively modest, incremental revision of the experiment reduces these misconceptions and helped the students to develop a molecular-scale picture of the processes that occur within an electrochemical cell.

  3. Discrimination of excess toxicity from baseline level for ionizable compounds: Effect of pH.

    PubMed

    Li, Jin J; Zhang, Xu J; Wang, Xiao H; Wang, Shuo; Yu, Yang; Qin, Wei C; Su, Li M; Zhao, Yuan H

    2016-03-01

    The toxic effect can be affected by pH in water through affecting the degree of ionization of ionizable compounds. Wrong classification of mode of action can be made from the apparent toxicities. In this paper, the toxicity data of 61 compounds to Daphnia magna determined at three pH values were used to investigate the effect of pH on the discrimination of excess toxicity. The results show that the apparent toxicities are significantly less than the baseline level. Analysis on the effect of pH on bioconcentration factor (BCF) shows that the log BCF values are significantly over-estimated for the strongly ionizable compounds, leading to the apparent toxicities greatly less than the baseline toxicities and the toxic ratios greatly less than zero. A theoretical equation between the apparent toxicities and pH has been developed basing on the critical body residue (CBR). The apparent toxicities are non-linearly related to pH, but linearly to fraction of unionized form. The determined apparent toxicities are well fitted with the toxicities predicted by the equation. The toxicities in the unionized form calculated from the equation are close to, or greater than the baseline level for almost all the strongly ionizable compounds, which are very different from the apparent toxicities. The studied ionizable compounds can be either classified as baseline, less inert or reactive compounds in D. magna toxicity. Some ionizable compounds do not exhibit excess toxicity at a certain pH, due not to their poor reactivity with target molecules, but because of the ionization in water.

  4. Determination of the major phenolic compounds in pomegranate juices by HPLC−DAD−ESI-MS.

    PubMed

    Gómez-Caravaca, Ana María; Verardo, Vito; Toselli, Moreno; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Caboni, Maria Fiorenza

    2013-06-01

    Traditionally, pomegranate (Punica granatum L.) has been consumed as fresh fruit or as pomegranate juice. In this study, the main phenolic compounds of 12 pomegranate varieties and 5 pomegranate clones were determined by HPLC−DAD−ESI-MS. Two chromatographic methods with a fused-core C18 column and a classical HPLC system were developed. Thirteen anthocyanins and fourteen other phenolic compounds were determined in the pomegranate juices. As far as we are concerned, a new flavonol-glycoside, phellatin or its isomer amurensin, has been tentatively identified for the first time in pomegranate juices. Total phenolic content ranged from 580.8 to 2551.3 mg/L of pomegranate juice. Anthocyanins varied between 20 to 82% of total phenolic content. Flavonoids were 1.6-23.6% of total phenolic compounds, while phenolic acids and ellagitannins were in the range 16.4-65.8%. The five clones reported a phenolic content comparable with that of the other pomegranate samples.

  5. Simultaneous determination of fermented milk aroma compounds by a potentiometric sensor array.

    PubMed

    Hruskar, Mirjana; Major, Nikola; Krpan, Marina; Vahcić, Nada

    2010-09-15

    The paper reports on the application of an electronic tongue for simultaneous determination of ethanol, acetaldehyde, diacetyl, lactic acid, acetic acid and citric acid content in probiotic fermented milk. The alphaAstree electronic tongue by Alpha M.O.S. was employed. The sensor array comprised of seven non-specific, cross-sensitive sensors developed especially for food analysis coupled with a reference Ag/AgCl electrode. Samples of plain, strawberry, apple-pear and forest-fruit flavored probiotic fermented milk were analyzed both by standard methods and by the potentiometric sensor array. The results obtained by these methods were used for the development of neural network models for rapid estimation of aroma compounds content in probiotic fermented milk. The highest correlation (0.967) and lowest standard deviation of error for the training (0.585), selection (0.503) and testing (0.571) subset was obtained for the estimation of ethanol content. The lowest correlation (0.669) was obtained for the estimation of acetaldehyde content. The model exhibited poor performance in average error and standard deviations of errors in all subsets which could be explained by low sensitivity of the sensor array to the compound. The obtained results indicate that the potentiometric electronic tongue coupled with artificial neural networks can be applied as a rapid method for the determination of aroma compounds in probiotic fermented milk.

  6. [Research on determination of total volatile organic sulfur compounds in the atmosphere].

    PubMed

    Wang, Yan-Jun; Zheng, Xiao-Ling; He, Ying; Zhang, Dong; Wang, Bao-Dong

    2011-12-01

    A detection technology was established comprising trap, desorption, oxidation and UV fluorescence determination process, and used for the test of total concentration of trace volatile sulfur compounds (VSCs) in the atmosphere. A cryogenic trap-thermal desorption device was developed, integrating the advantages of solid retention method and cryogenic condensation method, which was applied to capture and enrich trace volatile organic sulfur compounds. Under high temperature and combustion-supporting gas, the VSCs were completely oxidized into sulfur dioxide. By analyzing the content of sulfur dioxide through ultraviolet fluorescence method indirectly calculated to gain the total concentration of volatile organic sulfur compounds. The trapping temperature, desorption temperature and the oxidation temperature were 5 degrees C, 150 degrees C and 1 000 degrees C, and the precision and recovery of the method were 5.46% and 99.6%-109.2%, respectively. The content of trace amounts of atmospheric VSCs determined from February to April at Qingdao was 42-195 ng x m(-3).

  7. Determination of phenolic compounds in air by using cyclodextrin-silica hybrid microporous composite samplers.

    PubMed

    Mauri-Aucejo, Adela R; Ponce-Català, Patricia; Belenguer-Sapiña, Carolina; Amorós, Pedro

    2015-03-01

    An analytical method for the determination of phenolic compounds in air samples based on the use of cyclodextrin-silica hybrid microporous composite samplers is proposed. The method allows the determination of phenol, guaiacol, cresol isomers, eugenol, 4-ethylphenol and 4-ethylguaiacol in workplaces according to the Norm UNE-EN 1076:2009 for active sampling. Therefore, the proposed method offers an alternative for the assessment of the occupational exposure to phenol and cresol isomers. The detection limits of the proposed method are lower than those for the NIOSH Method 2546. Storage time of samples almost reaches 44 days. Recovery values for phenol, guaiacol, o-cresol, m-cresol, p-cresol, 4-ethylguaiacol, eugenol and 4-ethylphenol are 109%, 99%, 102%, 94%, 94%, 91%, 95% and 102%, respectively with a coefficient of variation below 6%. The method has been applied to the assessment of exposure in different areas of a farm and regarding the quantification of these compounds in the vapors generated by burning incense sticks and an essential oil marketed as air fresheners. The acquired results are comparable with those provided from a reference method for a 95% of confidence level. The possible use of these samplers for the sampling of other toxic compounds such as phthalates is evaluated by qualitative analysis of extracts from incense sticks and essential oil samples.

  8. Rapid determination of organotin compounds by headspace solid-phase microextraction.

    PubMed

    Le Gac, Marjorie; Lespes, Gaëtane; Potin-Gautier, Martine

    2003-05-30

    Headspace solid-phase microextraction (SPME) followed by gas chromatography (GC) coupled to pulsed flame photometric detection have been investigated for the simultaneous speciation analysis of 14 organotin compounds, including methyl-, butyl-, phenyl-, and octyltins compounds. The analytical process (sorption on SPME fibre and thermal desorption in GC injection port) has been optimised using experimental designs. Six operating factors were considered in order to evaluate their influence on the performances of a SPME-based procedure. The evaluation of accuracy, precision and limits of detection (LODs) according to ISO standards and IUPAC recommendations has allowed the method to be validated. The LODs obtained for the 14 studied organotins compounds are widely sub-ng(Sn) l(-1). The precision evaluated using relative standard deviation ranges between 9 and 25% from five determinations of the analytes at 0.25-125 ng(Sn) l(-1) concentrations. The accuracy was studied throughout the analysis of spiked environmental samples. These first results show that headspace SPME appears really as attractive for organotins determination in the environment and the monitoring of their biogeochemical cycle. PMID:12885057

  9. [Health effects of exposure of humans to inorganic arsenic compounds].

    PubMed

    Szymańska, J A; Chmielnicka, J

    1991-01-01

    This paper is a review of references concerning health effects of environmental and occupational exposure to inorganic arsenic compounds. Special attention is paid to epidemiological studies indicating a relationship between time and amount of arsenic absorbed via the gastrointestinal tract (drinking water, contaminated food, drugs) and an increase in skin cancer rate. Occupational and environmental exposure of humans to arsenic dust induces a higher risk of lung cancer.

  10. Effects of plant antimicrobial phenolic compounds on virulence of the genus Pectobacterium.

    PubMed

    Joshi, Janak Raj; Burdman, Saul; Lipsky, Alexander; Yedidia, Iris

    2015-01-01

    Pectobacterium spp. are among the most devastating necrotrophs, attacking more than 50% of angiosperm plant orders. Their virulence strategy is based mainly on the secretion of exoenzymes that degrade the cell walls of their hosts, providing nutrients to the bacteria, but conversely, exposing the bacteria to plant defense compounds. In the present study, we screened plant-derived antimicrobial compounds, mainly phenolic acids and polyphenols, for their ability to affect virulence determinants including motility, biofilm formation and extracellular enzyme activities of different Pectobacteria: Pectobacterium carotovorum, P. brasiliensis, P. atrosepticum and P. aroidearum. In addition, virulence assays were performed on three different plant hosts following exposure of the bacteria to selected phenolic compounds. These experiments showed that cinnamic, coumaric, syringic and salicylic acids and catechol can considerably reduce disease severity, ranging from 20 to 100%. The reduced disease severity was not only the result of reduced bacterial growth, but also of a direct effect of the compounds on important bacterial virulence determinants, including pectolytic and proteolytic exoenzyme activities, that were reduced by 50-100%. This is the first report revealing a direct effect of phenolic compounds on virulence factors in a wide range of Pectobacterium strains.

  11. Determination of Caffeine and Other Purine Compounds in Food and Pharmaceuitcals by Micellar Electrokinetic Chrmoatography

    NASA Astrophysics Data System (ADS)

    Vogt, Carla; Contradi, S.; Rohde, E.

    1997-09-01

    Capillary elctrophoresis is a modern separation technique, especially the extremely high efficiencies and minimal requirements with regard to buffers, samples and solvents lead to a dramatic increase of applications in the last few years. This paper offers an introduction to the technique of micellar elektrokinetic chromatography as a special kind of capillary electrophoresis. Caffeine and other purine compounds have been determined in foodstuff (tea, coffee, cocoa) as well as in pharmaceutical formulations. Different sample preparation procedures which have been developed with regard to the special properties of the sample matrices are discussed in the paper.This preparation facilitates the separation in many cases. So students have to solve a relatively simple separation problem by variation of buffer pH, buffer components and separation parameters. By doing a calibration for the analyzed purine compounds they will learn about reproducibility in capillary electrophoresis.

  12. Determination of tetraalkyllead compounds in gasoline by liquid chromatography-atomic absorption spectrometry

    USGS Publications Warehouse

    Messman, J.D.; Rains, T.C.

    1981-01-01

    A liquid chromatography-atomic absorption spectrometry (LC-AAS) hybrid analytical technique is presented for metal speciation measurements on complex liquid samples. The versatility and inherent metal selectivity of the technique are Illustrated by the rapid determination of five tetraalkyllead compounds in commercial gasoline. Separation of the individual tetraalkyllead species is achieved by reversed-phase liquid chromatography using an acetonitrile/water mobile phase. The effluent from the liquid Chromatograph Is introduced directly into the aspiration uptake capillary of the nebulizer of an air/acetylene flame atomic absorption spectrometer. Spectral interferences due to coeluting hydrocarbon matrix constituents were not observed at the 283.3-nm resonance line of lead used for analysis. Detection limits of this LC-AAS hydrid analytical technique, based on a 20-??L injection, are approximately 10 ng Pb for each tetraalkyllead compound.

  13. High-temperature operating biosensor for the determination of phenol and related compounds

    SciTech Connect

    Rella, R.; Ferrara, D.; Barison, G.; Doretti, L.

    1996-08-01

    Living phenol-oxidizing Bacillus stearothermophilus cells were immobilized in a hydroxyethyl methacrylate membrane. A thermostable biosensor was developed by coupling the bacterially activated membrane with a dissolved oxygen electrode and was utilized for the amperometric determination of phenols. Linear relationships were obtained for phenol, catechol and some related compounds. The steady-state response was very fast (max. 2 min), faster than other analogous biosensors. Its response was stable, reproducible for months and quite specific. The biosensor may be utilized over a wide temperature (35-55{degrees}C), pH (4.5-8.0) range and in matrices containing compounds toxic for most microorganisms and enzymes used. The best performance was observed at 55{degrees}C and pH 7.2. Owing to its sensitivity, stability and operational simplicity, the phenol biosensor can potentially be applied for the on-line monitoring of phenols in industrial waste effluents. 29 refs., 7 figs., 1 tab.

  14. Cytochrome c biosensor for determination of trace levels of cyanide and arsenic compounds.

    PubMed

    Fuku, Xolile; Iftikar, Faiza; Hess, Euodia; Iwuoha, Emmanuel; Baker, Priscilla

    2012-06-12

    An electrochemical method based on a cytochrome c biosensor was developed, for the detection of selected arsenic and cyanide compounds. Boron doped diamond (BDD) electrode was used as a transducer, onto which cytochrome c was immobilised and used for direct determination of Prussian blue, potassium cyanide and arsenic trioxide. The sensitivity as calculated from cyclic voltammetry (CV) and square wave voltammetry (SWV), for each analyte in phosphate buffer (pH=7) was found to be in the range of (1.1-4.5)×10(-8) A μM(-1) and the detection limits ranged from 4.3 to 9.1 μM. The biosensor is therefore able to measure significantly lower than current Environmental Protection Agency (EPA) and World Health Organisation (WHO) guidelines, for these types of analytes. The protein binding was monitored as a decrease in biosensor peak currents by SWV and as an increase in biosensor charge transfer resistance by electrochemical impedance spectroscopy (EIS). EIS provided evidence that the electrocatalytic advantage of BDD electrode was not lost upon immobilisation of cytochrome c. The interfacial kinetics of the biosensor was modelled as equivalent electrical circuit based on electrochemical impedance spectroscopy data. UV-vis spectroscopy was used to confirm the binding of the protein in solution by monitoring the intensity of the soret bands and the Q bands. FTIR was used to characterise the protein in the immobilised state and to confirm that the protein was not denatured upon binding to the pre-treated bare BDD electrode. SNFTIR of cyt c immobilised at platinum electrode, was used to study the effect of oxidation state on the surface bond vibrations. The spherical morphology of the immobilised protein, which is typical of native cytochrome c, was observed using scanning electron microscopy (SEM) and confirmed the immobilisation of the cytochrome c without denaturisation.

  15. Cytotoxic and clastogenic effects of soluble chromium compounds on mammalian cell cultures.

    PubMed Central

    Levis, A. G.; Majone, F.

    1979-01-01

    The inhibition of cell growth, the reduction of cell survival and the induction of chromosome aberrations and of sister chromatid exchange (SCE) have been determined in cultured hamster cell lines (BHK and CHO) treated with 11 water-soluble compounds of hexavalent and trivalent chromium. All Cr6+ compounds inhibit growth of BHK cells and reduce survival of CHO cells to levels comparable to those obtained only after exposure to 100--1000 times higher Cr3+ concentrations. The cytotoxicity curves obtained with the different Cr6+ compounds are almost overlapping, whereas marked differences of activity are noticeable among Cr3+ compounds. Giant cells are obtained after exposure to Cr6+ and Cr3+ compounds, as shown by the rise of DNA and RNA per cell, and are due to the blockage of the cell cycle without sudden inhibition of macromolecular syntheses. Both Cr6+ and Cr3+ compounds are able to induce chromosome aberrations, whereas Cr3+ is absolutely incapable of inducing SCE, only Cr6+ being active. The frequency of chromosome aberrations is increased about 10-fold after exposure to 1.0 micrograms/ml Cr6+, whereas it is only doubled after treatment with up to 150 micrograms/ml Cr3+. On the other hand, in spite of the sensitivity of CHO cells to the induction of SCE by mitomycin C, the frequency of SCE hardly doubles after exposure to Cr6+ compounds. The present data confirm that Cr6+ compounds are characterized by a marked cytotoxicity and clastogenic action on mammalian cell cultures and show that Cr3+ compounds, though cytotoxic only at extremely high concentrations and not increasing the frequency of SCE, are not completely without cytogenetic effect, as they are able to induce chromosome aberrations. PMID:497104

  16. Determination of phenolic compounds in honey using dispersive liquid-liquid microextraction.

    PubMed

    Campone, Luca; Piccinelli, Anna Lisa; Pagano, Imma; Carabetta, Sonia; Di Sanzo, Rosa; Russo, Mariateresa; Rastrelli, Luca

    2014-03-21

    Honey is a valuable functional food rich in phenolic compounds with a broad spectrum of biological activities. Analysis of the phenolic compounds in honey is a very promising tool for the quality control, the authentication and characterization of botanical origin, and the nutraceutical research. This work describes a novel approach for the rapid analysis of five phenolic acids and 10 flavonoids in honey. Phenolic compounds were rapidly extracted and concentrated from diluted honey by dispersive liquid-liquid microextraction (DLLME) and then analyzed using high performance liquid chromatography with UV absorbance detection (HPLC-UV). Some important parameters, such as the nature and volume of extraction and dispersive solvents, pH and salt effect were carefully investigated and optimized to achieve the best extraction efficiency. Under the optimal conditions, an exhaustive extraction for twelve of the investigated analytes (recoveries >70%), with a precision (RSD<10%) highly acceptable for complex matrices, and detection and quantification limits at ppb levels (1.4-12 and 4.7-40ngg(-1), respectively) were attained. The proposed method, compared with the most widely used method in the analysis of phenolic compounds in honey, provided similar or higher extraction efficiency, except in the case of the most hydrophilic phenolic acids. The capability of DLLME to the extraction of other honey phytochemicals, such as abscisic acid, was also demonstrated. The main advantages of developed method are the simplicity of operation, the rapidity to achieve a very high sample throughput and low cost.

  17. Determination of bioactive compounds in the juice of pummelo (Citrus grandis Osbeck).

    PubMed

    Russo, Marina; Bonaccorsi, Ivana; Torre, Germana; Cotroneo, Antonella; Dugo, Paola; Mondello, Luigi

    2013-02-01

    The juice of pummelo (Citrus grandis Osbeck) was analyzed to determine its composition of flavonoids, polymethoxyflavones, coumarins and psoralens. The analyses were carried out by HPLC using columns packed with small diameter Fused-Core C18 particles to achieve high resolution in short analysis time. In addition, the profile of the native carotenoids present in the juice was determined using a C30 column. Identification of flavonoids was achieved by MS with ESI in negative mode; the MS acquisition of oxygenated heterocyclic compounds was performed in positive APCI; carotenoids were detected with a PDA detector. Nineteen native carotenoids were determined in pummelo juice for the first time. The composition of this juice is also discussed in comparison with other Citrus juices, especially grapefruit.

  18. Pulmonary effects of polyvinyl chloride dust exposure on compounding workers.

    PubMed

    Ng, T P; Lee, H S; Low, Y M; Phoon, W H; Ng, Y L

    1991-02-01

    Spirometry, chest radiography, environmental measurements, and a questionnaire on respiratory symptoms were used to evaluate the effects of exposure to polyvinyl chloride (PVC) dust on 171 Chinese and Malay PVC compounding workers in comparison with an unexposed reference group. Workers with high cumulative PVC dust exposure had a lower forced expiratory volume in 1 s and forced vital capacity, and a higher prevalence of radiological profusion of small opacities. Wheezing or chest tightness was also significantly more frequent in this group. Unlike previous studies, the PVC compounding workers in this study were exposed to only negligible amounts, if any, of vinyl chloride monomer or thermal degradation products of PVC such as hydrogen chloride, phosgene, or chlorine. The conclusion was drawn that a low grade of pneumoconiosis and a small degree of lung function impairment is associated with PVC dust exposure. Reversible airways obstruction is also likely and warrants further investigation.

  19. Antifoaming effect of chemical compounds in manure biogas reactors.

    PubMed

    Kougias, P G; Tsapekos, P; Boe, K; Angelidaki, I

    2013-10-15

    A precise and efficient antifoaming control strategy in bioprocesses is a challenging task as foaming is a very complex phenomenon. Nevertheless, foam control is necessary, as foam is a major operational problem in biogas reactors. In the present study, the effect of 14 chemical compounds on foam reduction was evaluated at concentration of 0.05%, 0.1% and 0.5% v/v(sample), in raw and digested manure. Moreover, two antifoam injection methods were compared for foam reduction efficiency. Natural oils (rapeseed and sunflower oil), fatty acids (oleic, octanoic and derivative of natural fatty acids), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were more efficient in reducing foam when added directly into the liquid phase rather than added in the headspace of the reactor.

  20. Determination of endocrine disrupting compounds using temperature-dependent inclusion chromatography: I. Optimization of separation protocol.

    PubMed

    Zarzycki, Paweł K; Włodarczyk, Elzbieta; Baran, Michał J

    2009-10-30

    In the present work we optimised the separation of battery of key UV non-transparent low-molecular-mass compounds having possible endocrine disrupting compounds (EDCs) activity or which may be used as the endocrine effect biomarkers. Simple optimization strategy was based on strong temperature effect that is driven by electrostatic interactions between macrocyclic mobile phase additives like cyclodextrins and eluted components of interest under C18 stationary phase and acetonitrile/water mobile phase conditions. Particularly, the effect of temperature involving native beta-cyclodextrin and its hydroxypropyl derivative to improve separation of number of natural (d-equilenin, equilin, estetrol, estriol, estrone, 17beta-estradiol, 17alpha-hydroxyprogesterone, 20alpha-hydroxyprogesterone, cortisol, cortisone, progesterone, testosterone, tetrahydrocortisol and tetrahydrocortisone) and artificial steroids (ethynylestradiol, norgestrel isomers, medroxyprogesterone, mestranol, methyltestosterone, norethindrone, 17alpha-estradiol) as well as non-steroidal compounds (diethylstilbesterol, bisphenol A, 4-tert-butylphenol, dimethyl phthalate, dibutyl phthalate and dioctyl phthalate) was investigated. It has been found that successful isocratic separation of 27 chemicals can be achieved using acetonitrile/water eluents modified with beta-cyclodextrin or hydroxypropyl-beta-cyclodextrin at concentration of 10 mM and temperature of 47 degrees C. Separation protocol is simple, reliable, direct and non-radioactive and may be easily adapted for rapid separation and quantification of wide range of given steroids and related EDCs in environmental samples, particularly those that are characterised by unstable biological matrix and components of interest load. PMID:19362314

  1. Fate and occurrence of alkylphenolic compounds in sewage sludges determined by liquid chromatography tandem mass spectrometry.

    PubMed

    Koh, Y K K; Chiu, T Y; Paterakis, N; Boobis, A; Scrimshawe, M D; Lester, J N; Cartmell, E

    2009-12-01

    An analytical method has been developed and applied to determine the concentrations of the nonionic alkylphenol polyethoxylate surfactants and their metabolites, alkylphenoxy carboxylates and alkyphenols, in sewage sludges. The compounds were extracted with methanol/acetone (1:1 v/v) from sludge, and concentrated extracts were cleaned by silica solid-phase extraction prior to determination by liquid chromatography tandem mass spectrometry. The recoveries, determined by spiking sewage sludge at two concentrations, ranged from 51% to 89% with method detection limits from 6 microg kg(-1) to 60 microg kg(-1). The methodology was subsequently applied to sludge samples obtained from a carbonaceous activated sludge plant, a nitrifying/denitrifying activated sludge plant and a nitrifying/ denitrifying activated sludge plant with phosphorus removal. Concentrations of nonylphenolic compounds were two to three times higher than their octyl analogues. Long-chain nonylphenol polyethoxylates (NP3-12EO) ranged from 16 microg kg(-1) to 11754 microg kg(-1). The estrogenic metabolite nonylphenol was present at concentrations ranging from 33 microg kg(-1) to 6696 microg kg(-1). PMID:20088206

  2. Surface Bonding Effects in Compound Semiconductor Nanoparticles: II

    SciTech Connect

    Helen H. Farrell

    2008-07-01

    Small nanoparticles have a large proportion of their atoms either at or near the surface, and those in clusters are essentially all on the surface. As a consequence, the details of the surface structure are of paramount importance in governing the overall stability of the particle. Just as with bulk materials, factors that determine this stability include “bulk” structure, surface reconstruction, charge balance and hybridization, ionicity, strain, stoichiometry, and the presence of adsorbates. Needless to say, many of these factors, such as charge balance, hybridization and strain, are interdependent. These factors all contribute to the overall binding energy of clusters and small nanoparticles and play a role in determining the deviations from an inverse size dependence that we have previously reported for compound semiconductor materials. Using first-principles density functional theory calculations, we have explored how these factors influence particle stability under a variety of conditions.

  3. [Determination of compound preparation containing unknown absorptive background by UV spectrophotometry].

    PubMed

    Guo, Y L; Xiang, B R; An, D K

    1991-01-01

    A novel algorithm of target factor analysis has been developed for detection and correction of unknown absorptive background in multicomponent analysis. The algorithm is based on the property that the estimated spectra can gradually approach the true ones by iterative refinements. Paracetamol and antipyrine contained in compound injection of paracetamol were determined by this method without any preliminary chemical separation. The average recoveries were both 100.0% and the coefficients of variation were 1.1% and 1.0% respectively. The results clearly indicate that the proposed method may also provide a new approach to the analysis of traditional Chinese medicine containing some unknown absorptive components. PMID:1789114

  4. Comparison of different extraction techniques for the determination of polychlorinated organic compounds in sediment.

    PubMed

    Martens, D; Gfrerer, M; Wenzl, T; Zhang, A; Gawlik, B M; Schramm, K W; Lankmayr, E; Kettrup, A

    2002-02-01

    The performance of various enhanced extraction techniques, such as accelerated solvent extraction, microwave-assisted extraction, Soxhlet extraction, ultrasonic extraction and fluidized-bed extraction for the determination of polychlorinated organic compounds in dry sediment was investigated in two laboratories. The results of the two laboratories were in good agreement. The extraction yields from the batch extraction methods were lower than those from the dynamic techniques. Accelerated solvent extraction, especially, exhibited higher extraction efficiency than the standard procedure, Soxhlet extraction, whereas the results of fluidized-bed extraction were comparable. PMID:11939632

  5. Determination of synthetic musk compounds in sewage biosolids by gas chromatography/mass spectrometry.

    PubMed

    Osemwengie, Lantis I

    2006-09-01

    A review of sewage sludge regulations and land application practices by the United States National Research Council (2002) recommended development of improved analytical techniques to adequately identify and quantify new chemical contaminants, such as synthetic musk compounds in Class A sewage sludge (i.e., biosolids). This prompted the development of a rugged analytical method using gas chromatography coupled to mass spectrometry to detect this group of organic pollutants in biosolids. In this paper, the term "biosolids" is used interchangeably with "sewage sludge", which is defined in the regulations and used in the statue (Clean Water Act). Samples of Class A biosolids obtained from sewage treatment plants in Los Angeles, California, the City of Las Vegas, Nevada, and also in the form of a commercial fertilizer, were extracted using pressurized liquid extraction technique, subjected to gel permeation chromatography clean-up, and analyzed by GC/MS using the selected ion monitoring mode. The method developed has the potential to detect synthetic musk compounds in complex matrices, may provide accurate data useful in human health and environmental risk assessment, and may be useful in determining the efficacy of municipal sewage treatment plants for removing synthetic musk compounds. PMID:16951749

  6. Determination of volatile compounds and quality parameters of traditional Istrian dry-cured ham.

    PubMed

    Marušić, Nives; Vidaček, Sanja; Janči, Tibor; Petrak, Tomislav; Medić, Helga

    2014-04-01

    The aim of this work was to determine the characteristics of Istrian dry-cured ham by instrumental methods and sensory analysis. The aroma-active compounds of Istrian dry-cured ham from 2010 and 2012 were investigated by using headspace-solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics. 92 volatile aroma compounds of Istrian dry-cured ham were found. Volatile compounds belonged to several chemical groups: aldehydes (51.4; 51.3%), terpenes (16.5; 16.4%), alcohols (15.5; 13.2%), ketones (8.6; 7.4%), alkanes (3.8; 5.7%), esters (1.3; 1.6%), aromatic hydrocarbons (0.8; 3.9%) and acids (0.6; 0.9%). Principal component analysis (PCA) showed that fat content, tenderness and melting texture were positively correlated. Terpenes were strongly correlated with flavour of added spices. Sweet taste and the presence of esters were positively correlated as well as negative odour, raw meat flavour and water content. PMID:24398000

  7. Determination of synthetic musk compounds in sewage biosolids by gas chromatography/mass spectrometry.

    PubMed

    Osemwengie, Lantis I

    2006-09-01

    A review of sewage sludge regulations and land application practices by the United States National Research Council (2002) recommended development of improved analytical techniques to adequately identify and quantify new chemical contaminants, such as synthetic musk compounds in Class A sewage sludge (i.e., biosolids). This prompted the development of a rugged analytical method using gas chromatography coupled to mass spectrometry to detect this group of organic pollutants in biosolids. In this paper, the term "biosolids" is used interchangeably with "sewage sludge", which is defined in the regulations and used in the statue (Clean Water Act). Samples of Class A biosolids obtained from sewage treatment plants in Los Angeles, California, the City of Las Vegas, Nevada, and also in the form of a commercial fertilizer, were extracted using pressurized liquid extraction technique, subjected to gel permeation chromatography clean-up, and analyzed by GC/MS using the selected ion monitoring mode. The method developed has the potential to detect synthetic musk compounds in complex matrices, may provide accurate data useful in human health and environmental risk assessment, and may be useful in determining the efficacy of municipal sewage treatment plants for removing synthetic musk compounds.

  8. Determination of volatile compounds and quality parameters of traditional Istrian dry-cured ham.

    PubMed

    Marušić, Nives; Vidaček, Sanja; Janči, Tibor; Petrak, Tomislav; Medić, Helga

    2014-04-01

    The aim of this work was to determine the characteristics of Istrian dry-cured ham by instrumental methods and sensory analysis. The aroma-active compounds of Istrian dry-cured ham from 2010 and 2012 were investigated by using headspace-solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics. 92 volatile aroma compounds of Istrian dry-cured ham were found. Volatile compounds belonged to several chemical groups: aldehydes (51.4; 51.3%), terpenes (16.5; 16.4%), alcohols (15.5; 13.2%), ketones (8.6; 7.4%), alkanes (3.8; 5.7%), esters (1.3; 1.6%), aromatic hydrocarbons (0.8; 3.9%) and acids (0.6; 0.9%). Principal component analysis (PCA) showed that fat content, tenderness and melting texture were positively correlated. Terpenes were strongly correlated with flavour of added spices. Sweet taste and the presence of esters were positively correlated as well as negative odour, raw meat flavour and water content.

  9. Determination of cytotoxic compounds of Thai traditional medicine called Benjakul using HPLC.

    PubMed

    Itharat, Arunporn; Sakpakdeejaroen, Intouch

    2010-12-01

    Benjakul is a Thai traditional medicine preparation, used for balanced health. From selective interviews of folk doctors in southern Thailand, it was used as the adaptogen drug for cancer patients. In our previous study, the ethanolic extract of Benjakul preparation exhibited high cytotoxic activity against lung cancer cell lines (COR-L23). Piperine has been identified as the main compound in the extract. In addition, plumbagin was found as the most cytotoxic compound. In this study, a reversed-phase high performance liquid chromatography (HPLC) method for quality control such as chemical fingerprint, quantification and stability of the ethanolic extract of Benjakul preparation was developed. The reversed-phase HPLC was performed with a gradient mobile phase composed of water and acetronitrile, and peaks were detected at 256 nm. Based on validation results, this analytical method is precise, accurate and stable for quantitative determination of piperine and plumbagin which are cytotoxic compounds isolated from the ethanolic extract of Benjakul preparation. This method could be suitable for analysis of Benjakul extract. PMID:21294415

  10. Simultaneous Determination of Eight Bioactive Compounds in Dianthus superbus by High-performance Liquid Chromatography

    PubMed Central

    Yun, Bo-Ra; Yang, Hye Jin; Weon, Jin Bae; Lee, Jiwoo; Eom, Min Rye; Ma, Choong Je

    2016-01-01

    Background: Dianthus superbus, one of traditional herbal medicine, is widely used to treat urethritis, carbuncles and carcinoma. Objective: A simultaneous determination method was established for controlling the quality of D. superbus using the eight compounds, (E)-methyl-4-hydroxy-4-(8a-methyl-3-oxodecahydronaphthalen-4a-yl) (1), diosmetin-7-O(2'',6''-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), vanillic acid (3), 4-hydroxyphenyl acetic acid (4), 4-methoxyphenyl acetic acid (5), (E)-4-methoxycinnamic acid (6), 3-methoxy-4-hydroxyphenylethanol (7), and methyl hydroferulate (8) isolated from D. superbus. Materials and Methods: This analysis method was developed using high performance liquid chromatography coupled with diode array detector with a Shishedo C18 column at a column temperature of 3°C. The mobile phase was composed of 0.1% trifluoroacetic acid in water and acetonitrile. The flow rate was 1 ml/min and detection wavelength was set at 205 nm and 280 nm. Validation was performed in order to demonstrate selectivity, accuracy and precision of the method. Results: The calibration curves showed good linearity (R2 > 0.99). The limits of detection and limits of quantification were within the ranges 0.0159–0.6205 μg/ml and 0.3210–1.8802 μg/ml, respectively. Moreover, the relative standard deviations of intra- and inter-day precision were both <2.98%. The overall recoveries were in the range of 96.23–109.87%. Quantitative analysis of eight compounds in 12 D. superbus samples (D-1–D-12) from various regions were analyzed and compared by developed method. Conclusion: As a result, this established method was accurate and sensitive for the quality evaluation of eight compounds isolated from D. superbus and may provide a new basis for quality control of D. superbus. SUMMARY A simultaneous determination method of eight compounds in Dianthus superbus was established by high performance liquid chromatography-diode array detectorDeveloped analysis method is

  11. Ultrasound-assisted emulsification-microextraction for the determination of phenolic compounds in olive oils.

    PubMed

    Reboredo-Rodríguez, P; Rey-Salgueiro, L; Regueiro, J; González-Barreiro, C; Cancho-Grande, B; Simal-Gándara, J

    2014-05-01

    A reliable, sensitive and effective method based on ultrasound-assisted emulsification-microextraction (USAEME) coupled to HPLC-DAD has been developed to identify and quantify several target phenolic compounds from extra virgin olive oils (EVOO). This approach is based on the emulsification of a microvolume of polar organic extractant in a non-polar liquid sample by ultrasound radiation and further separation of both liquid phases by centrifugation. The percentage of methanol/water (v/v) in the extractant, the volume of extractant, and the extraction time as three effective parameters on the extraction were optimised by a central composite design (Box-Behnken response surface) method. The optimised method presented recoveries in EVOO between 91% and 115% for the target analytes (except vanillin with 65%) and a satisfactory precision with relative standard deviations (RSD%) lower than 8.4% for repeatability and reproducibility. The method showed good linearity and limits of detection and quantification were in the range 0.001-0.14 and 0.004-0.47mg/kg, respectively. After method validation, it was successfully applied to the analysis of three EVOO samples. All target compounds were detected in all analysed samples. Tyrosol and hydroxytyrosol were the major phenolic compounds, followed by pinoresinol and luteolin. PMID:24360429

  12. Chemiluminescence vs. Kjeldahl determination of nitrogen in oil shale retort waters and organonitrogen compounds

    SciTech Connect

    Jones, B.M.; Daughton, C.G.

    1985-10-01

    The applicability of combustion/chemiluminescent nitrogen analysis to quantifying nitrogen in oil shale wastewaters and various representative chemical classes was demonstrated. Only azoxy compounds and those containing the pyrazole nucleus were not amenable to analysis. The majority of 56 compounds tested yielded from 90% to 110% of their theoretical nitrogen contents: enhanced recovery was found for nitrogen oxide salts. For 12 oil shale wastewaters, combustion/chemiluminescence gave total nitrogen values (1100-28800 mg/L) that did not differ statistically (P > 0.10) from those obtained by the time-consuming wet-chemical Kjeldahl method. The relative standard deviations for ten matrix or solvent effects were found. 28 references, 1 figure, 3 tables.

  13. Determining factor of median diameter in intermetallic compound nanoparticles prepared by pulsed wire discharge

    NASA Astrophysics Data System (ADS)

    Nagasawa, Shinobu; Koishi, Tetsuya; Tokoi, Yoshinori; Suzuki, Tsuneo; Nakayama, Tadachika; Suematsu, Hisayuki; Niihara, Koichi

    2014-02-01

    The preparation of NiAl intermetallic compound nanoparticles was carried out by pulsed wire discharge (PWD) using twisted pure Ni and Al wires in N2 ambient gas with varying number of turns of the wire (Nt), energy ratio (K), and ambient gas pressure (P). From the voltage and current waveforms during the wire heating, the energy deposition ratio up to the voltage peak (Kp) was calculated. It increased with an increase in Nt to 0.4 turns/mm and with increases in K and P. Under all the conditions, with an increase in Kp, the Ni composition ratio of the prepared particles (CNi) became closer to that of the wire (= 51.2 mol %). Furthermore, the collection rate (Rc) increased and the median particle diameter (d50) decreased. In particular, the change in d50 due to the change in Nt was not predicted by the relationship of d50 and Dth in our previous report. Single-phase NiAl intermetallic compound nanoparticles were successfully prepared under the condition in which Nt is 0.4 turns/mm, K is 3.4, and P is 100 kPa, where relatively high value of Kp was obtained. From these results, Kp was determined to be an important factor that determines the composition, collection rate, and median diameter of intermetallic compound nanoparticles synthesized by PWD using different kinds of twisted wires under various experimental conditions. This may be because of the selective wire heating in high-resistance parts that are associated with the introduction of lattice defects and/or necks by overwinding.

  14. Carbonyl compounds over urban Beijing: Concentrations on haze and non-haze days and effects on radical chemistry

    NASA Astrophysics Data System (ADS)

    Rao, Zhihan; Chen, Zhongming; Liang, Hao; Huang, Liubin; Huang, Dao

    2016-01-01

    Carbonyl compounds play an important role in the formation of secondary aerosols and the cycling of free radicals in the atmosphere. We measured carbonyl compounds over urban Beijing, a megacity in the North China Plain, in summer and winter to investigate the relation of carbonyl compounds with haze and the interaction between carbonyl compounds and atmospheric radical cycling. We also determined carbonyl compounds in summer rainwater. Data of carbonyl compounds were analyzed in four cases, i.e., summer haze days (SHD), summer non-haze days (SND), winter haze days (WHD), and winter non-haze days (WND). Interestingly, the level of carbonyl compounds during WHD approached that of summer days. The results of the principal component analysis showed that there was no obvious source difference between SHD and SND. On WHD, however, more carbonyl compounds originated from the "diesel engine exhaust emission" than those on WND. We evaluated the effect of carbonyl compounds on the free radical cycling and the NO consumption potential for OH formation in the photochemical reactions using a novel ratio method. It was found that the production rate of ROx (the sum of OH, HO2 and RO2 radicals) was highest on SND, while the yield of ROx radicals from the reactions of carbonyl compounds was highest on WHD. Further, carbonyl compounds consumed more NO to produce OH radicals on WHD compared to the other three cases.

  15. Determination of ruthenium in pharmaceutical compounds by graphite furnace atomic absorption spectroscopy.

    PubMed

    Jia, Xiujuan; Wang, Tiebang; Bu, Xiaodong; Tu, Qiang; Spencer, Sandra

    2006-04-11

    A graphite furnace atomic absorption (GFAA) spectrometric method for the determination of ruthenium (Rh) in solid and liquid pharmaceutical compounds has been developed. Samples are dissolved or diluted in dimethyl sulfoxide (DMSO) without any other treatment before they were analyzed by GFAA with a carefully designed heating program to avoid pre-atomization signal loss and to achieve suitable sensitivity. Various inorganic and organic solvents were tested and compared and DMSO was found to be the most suitable. In addition, ruthenium was found to be stable in DMSO for at least 5 days. Spike recoveries ranged from 81 to 100% and the limit of quantitation (LOQ) was determined to be 0.5 microg g(-1) for solid samples or 0.005 microg ml(-1) for liquid samples based a 100-fold dilution. The same set of samples was also analyzed by ICP-MS with a different sample preparation method, and excellent agreement was achieved. PMID:16314066

  16. Microextraction techniques used in the procedures for determining organomercury and organotin compounds in environmental samples.

    PubMed

    Rutkowska, Małgorzata; Dubalska, Kinga; Konieczka, Piotr; Namieśnik, Jacek

    2014-01-01

    Due to human activities, the concentrations of organometallic compounds in all parts of the environment have increased in recent decades. The toxicity and some biochemical properties of mercury and tin present in the environment depend on the concentration and chemical form of these two elements. The ever-increasing demand for determining compounds at very low concentration levels in samples with complex matrices requires the elimination of interfering substances, the reduction of the final extract volume, and analyte enrichment in order to employ a detection technique, which is characterised by high sensitivity at low limits of quantification. On the other hand, in accordance with current trends, the analytical procedures should aim at the miniaturisation and simplification of the sample preparation step. In the near future, more importance will be given to the fulfilment of the requirements of Green Chemistry and Green Analytical Chemistry in order to reduce the intensity of anthropogenic activities related to analytical laboratories. In this case, one can consider the use of solvent-free/solvent-less techniques for sample preparation and microextraction techniques, because the use of the latter leads to lowering the quantity of reagents used (including solvents) due to the reduction of the scale of analysis. This paper presents an overview of microextraction techniques (SPME and LPME) used in the procedures for determining different chemical forms of mercury and tin. PMID:24914902

  17. Small-size mass spectrometer for determining gases and volatile compounds in air during breathing

    NASA Astrophysics Data System (ADS)

    Kogan, V. T.; Kozlenok, A. V.; Chichagov, Yu. V.; Antonov, A. S.; Lebedev, D. S.; Bogdanov, A. A.; Moroshkin, V. S.; Berezina, A. V.; Viktorova-Leclerc, O. S.; Vlasov, S. A.; Tubol'tsev, Yu. V.

    2015-10-01

    We describe an automated mass spectrometer for diagnostics of deceases from the composition of exhaled air. It includes a capillary system, which performs a rapid direct feeding of the sample to the instrument without changing substantially its composition and serves for studying the dynamics of variation of the ratio between various components of exhaled air. The membrane system for introducing the sample is intended for determining low concentrations of volatile organic compounds which are biomarkers of pathologies. It is characterized by selective transmittance and ensures the detection limits of target compounds at the parts per million-parts per billion (ppm-ppb) level. A static mass analyzer operating on permanent magnets possesses advantages important for mobile devices as compared to its dynamic analogs: it is more reliable in operation, has a larger dynamic range, and can be used for determining the concentration of components in the mixture one-by-one or simultaneously. The curvilinear output boundary of the magnetic lens of the mass analyzer makes it possible to reduce its weight and size by 2.5 times without deteriorating the mass resolution. We report on the results of testing of the instrument and consider the possibility of its application for early detection of deceases of respiratory and blood circulation system, gastrointestinal tract, and endocrine system.

  18. Microextraction techniques for the determination of volatile and semivolatile organic compounds from plants: a review.

    PubMed

    Yang, Cui; Wang, Juan; Li, Donghao

    2013-10-17

    Vegetables and fruits are necessary for human health, and traditional Chinese medicine that uses plant materials can cure diseases. Thus, understanding the composition of plant matrix has gained increased attention in recent years. Since plant matrix is very complex, the extraction, separation and quantitation of these chemicals are challenging. In this review we focus on the microextraction techniques used in the determination of volatile and semivolatile organic compounds (such as esters, alcohols, aldehydes, hydrocarbons, ketones, terpenes, sesquiterpene, phenols, acids, plant secondary metabolites and pesticides) from plants (e.g., fruits, vegetables, medicinal plants, tree leaves, etc.). These microextraction techniques include: solid phase microextraction (SPME), stir-bar sorptive extraction (SBSE), single drop microextraction (SDME), hollow fiber liquid phase microextraction (HF-LPME), dispersive liquid liquid microextraction (DLLME), and gas purge microsyringe extraction (GP-MSE). We have taken into consideration papers published from 2008 to the end of January 2013, and provided critical and interpretative review on these techniques, and formulated future trends in microextraction for the determination of volatile and semivolatile compounds from plants. PMID:24091369

  19. A Tale of Two Frequencies: Determining the Speed of Lexical Access for Mandarin Chinese and English Compounds

    ERIC Educational Resources Information Center

    Janssen, Niels; Bi, Yanchao; Caramazza, Alfonso

    2008-01-01

    Two picture naming experiments show that compound word production in Mandarin Chinese and in English is determined by the compound's whole-word frequency, and not by its constituent morpheme frequency. Four control experiments rule out that these results are caused by recognition or articulatory processes. These results are consistent with models…

  20. Extraction and GC determination of volatile aroma compounds from extracts of three plant species of the Apiaceae family

    NASA Astrophysics Data System (ADS)

    Stan, M.; Soran, M. L.; Varodi, C.; Lung, I.; Copolovici, L.; MǎruÅ£oiu, C.

    2013-11-01

    Parsley (Petroselinum crispum), dill (Anethum graveolens) and celery (Apium graveolens), three aromatic plants belonging to the Apiaceae (Umbelliferae) botanical family, were selected as sources of essential or volatile oils. Essential oils are composed of a large diversity of volatile aroma compounds. Plant-derived essential oils and extracts have long been used as natural agents in food preservation, pharmaceuticals and medicinal therapies. In the present study, the plant extracts from leaves of parsley, dill and celery, were obtained by maceration, ultrasound-assisted extraction and microwave-assisted extraction. All extractions were performed at 30°C, using different solvents (ethanol, diethyl ether, n-hexane) and solvent mixtures (1:1, v/v). The most effective solvent system for the extraction of volatile aroma compounds was diethyl ether - n-hexane (1:1, v/v). Extraction efficiency and determination of aroma volatiles were performed by GC-FID and GC-MS, respectively. The major volatile compounds present in plant extracts were myristicin, α-phellandrene, β-phellandrene, 1,3,8-p-menthatriene, apiol, dill ether and allyl phenoxyacetate.

  1. Antimutagenic effects of ajoene, an organosulfur compound derived from garlic.

    PubMed

    Ishikawa, K; Naganawa, R; Yoshida, H; Iwata, N; Fukuda, H; Fujino, T; Suzuki, A

    1996-12-01

    The antimutagenic effects of ajoene, which is an organosulfur compound derived from garlic, were investigated by the Ames test. Ajoene inhibited mutagenesis induced by both benzo[a]pyrene (B[a]P) and 4-nitro-1,2-phenylenediamine (NPD) in a dose-dependent manner. In particular, NPD-induced mutagenesis was more effectively suppressed by ajoene than the B[a]P-induced type. Furthermore, the inhibition of mutagenesis by ajoene was more effective for transition-type mutations than for the frame shift type. HPLC analysis of B[a]P metabolism in the presence of the rat liver microsomal fraction (S-9) showed that ajoene dose-dependently inhibited the metabolic activation of B[a]P. This suggests that ajoene affected the metabolic enzymes in the S-9 fraction.

  2. In vitro determination of volatile compound development during starter culture-controlled fermentation of Cucurbitaceae cotyledons.

    PubMed

    Kamda, Aristide Guillaume Silapeux; Ramos, Cíntia Lacerda; Fokou, Elie; Duarte, Whasley Ferreira; Mercy, Achu; Germain, Kansci; Dias, Disney Ribeiro; Schwan, Rosane Freitas

    2015-01-01

    The effects of Lactobacillus plantarum UFLA CH3, Pediococcus acidilactici UFLA BFFCX 27.1, and Torulaspora delbrueckii UFLA FFT2.4 inoculation on the volatile compound profile of fermentation of Cucumeropsis mannii cotyledons were investigated. Different microbial associations were used as starters. All associations displayed the ability to ferment the cotyledons as judged by lowering the pH from 6.4 to 4.4-5 within 24h and increasing organic acids such as lactate and acetate. The population of lactic acid bacteria (LAB) and yeasts increased during fermentation. In the fermentation performed without inoculation (control), the LAB and yeast populations were lower than those in inoculated assays at the beginning, but they reached similar populations after 48 h. The Enterobacteriaceae population decreased during the fermentation, and they were not detected at 48 h in the L. plantarum UFLA CH3 and P. acidilactici UFLA BFFCX 27.1 (LP+PA) and L. plantarum UFLA CH3, P. acidilactici UFLA BFFCX 27.1, and T. delbrueckii UFLA FFT2.4 (LP+PA+TD) samples. The assays inoculated with the yeast T. delbrueckii UFLA FFT2.4 exhibited the majority of volatile compounds (13 compounds) characterized by pleasant notes. The LP+PA+TD association seemed to be appropriate to ferment C. mannii cotyledons. It was able to control the Enterobacteriaceae population, and achieved high concentrations of esters and low concentrations of aldehydes and ketones.

  3. In vitro determination of volatile compound development during starter culture-controlled fermentation of Cucurbitaceae cotyledons.

    PubMed

    Kamda, Aristide Guillaume Silapeux; Ramos, Cíntia Lacerda; Fokou, Elie; Duarte, Whasley Ferreira; Mercy, Achu; Germain, Kansci; Dias, Disney Ribeiro; Schwan, Rosane Freitas

    2015-01-01

    The effects of Lactobacillus plantarum UFLA CH3, Pediococcus acidilactici UFLA BFFCX 27.1, and Torulaspora delbrueckii UFLA FFT2.4 inoculation on the volatile compound profile of fermentation of Cucumeropsis mannii cotyledons were investigated. Different microbial associations were used as starters. All associations displayed the ability to ferment the cotyledons as judged by lowering the pH from 6.4 to 4.4-5 within 24h and increasing organic acids such as lactate and acetate. The population of lactic acid bacteria (LAB) and yeasts increased during fermentation. In the fermentation performed without inoculation (control), the LAB and yeast populations were lower than those in inoculated assays at the beginning, but they reached similar populations after 48 h. The Enterobacteriaceae population decreased during the fermentation, and they were not detected at 48 h in the L. plantarum UFLA CH3 and P. acidilactici UFLA BFFCX 27.1 (LP+PA) and L. plantarum UFLA CH3, P. acidilactici UFLA BFFCX 27.1, and T. delbrueckii UFLA FFT2.4 (LP+PA+TD) samples. The assays inoculated with the yeast T. delbrueckii UFLA FFT2.4 exhibited the majority of volatile compounds (13 compounds) characterized by pleasant notes. The LP+PA+TD association seemed to be appropriate to ferment C. mannii cotyledons. It was able to control the Enterobacteriaceae population, and achieved high concentrations of esters and low concentrations of aldehydes and ketones. PMID:25306300

  4. Effect of lignocellulosic degradation compounds from steam explosion pretreatment on ethanol fermentation by thermotolerant yeast Kluyveromyces marxianus.

    PubMed

    Oliva, Jose Miguel; Sáez, Felicia; Ballesteros, Ignacio; González, Alberto; Negro, Maria José; Manzanares, Paloma; Ballesteros, Mercedes

    2003-01-01

    The filtrate from steam-pretreated poplar was analyzed to identify degradation compounds. The effect of selected compounds on growth and ethanolic fermentation of the thermotolerant yeast strain Kluyveromyces marxianus CECT 10875 was tested. Several fermentations on glucose medium, containing individual inhibitory compounds found in the hydrolysate, were carried out. The degree of inhibition on yeast strain growth and ethanolic fermentation was determined. At concentrations found in the prehy-drolysate, none of the individual compounds significantly affected the fermentation. For all tested compounds, growth was inhibited to a lesser extent than ethanol production. Lower concentrations of catechol (0.96 g/L) and 4-hydroxybenzaldehyde (1.02 g/L) were required to produce the 50% reduction in cell mass in comparison to other tested compounds.

  5. Bioactive Compounds of Aristotelia chilensis Stuntz and their Pharmacological Effects.

    PubMed

    Romanucci, Valeria; D'Alonzo, Daniele; Guaragna, Annalisa; Di Marino, Cinzia; Davinelli, Sergio; Scapagnini, Giovanni; Di Fabio, Giovanni; Zarrelli, Armando

    2016-01-01

    Aristotelia chilensis ([Molina], Stuntz) a member of the family Eleocarpaceae, is a plant native to Chile that is distributed in tropical and temperate Asia, Australia, the Pacific Area, and South America. The juice of its berries has important medicinal properties, as an astringent, tonic, and antidiarrhoeal. Its many qualities make the maqui berry the undisputed sovereign of the family of so-called "superfruits", as well as a valuable tool to combat cellular inflammation of bones and joints. Recently, it is discovered that the leaves of the maqui berry have important antibacterial and antitumour activities. This review provides a comprehensive overview of the traditional use, phytochemistry, and biological activity of A. chilensis using information collected from scientific journals, books, and electronic searches. Anthocyanins, other flavonoids, alkaloids, cinnamic acid derivatives, benzoic acid derivatives, other bioactive molecules, and mineral elements are summarized. A broad range of activities of plant extracts and fractions are presented, including antioxidant activity, inhibition of visible light-induced damage of photoreceptor cells, inhibition of α-glucosidase, inhibition of pancreatic lipase, anti-diabetic effects, anti-inflammatory effects, analgesic effects, anti-diabetes, effective prevention of atherosclerosis, promotion of hair growth, anti-photo ageing of the skin, and inhibition of lipid peroxidation. Although some ethnobotanical uses have been supported in in vitro experiments, further studies of the individual compounds or chemical classes of compounds responsible for the pharmacological effects and the mechanisms of action are necessary. In addition, the toxicity and the side effects from the use of A. chilensis, as well as clinical trials, require attention. PMID:26778456

  6. Determination of the n-octanol/water partition coefficients of weakly ionizable basic compounds by reversed-phase high-performance liquid chromatography with neutral model compounds.

    PubMed

    Liang, Chao; Han, Shu-ying; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

    2014-11-01

    A strategy to utilize neutral model compounds for lipophilicity measurement of ionizable basic compounds by reversed-phase high-performance liquid chromatography is proposed in this paper. The applicability of the novel protocol was justified by theoretical derivation. Meanwhile, the linear relationships between logarithm of apparent n-octanol/water partition coefficients (logKow '') and logarithm of retention factors corresponding to the 100% aqueous fraction of mobile phase (logkw ) were established for a basic training set, a neutral training set and a mixed training set of these two. As proved in theory, the good linearity and external validation results indicated that the logKow ''-logkw relationships obtained from a neutral model training set were always reliable regardless of mobile phase pH. Afterwards, the above relationships were adopted to determine the logKow of harmaline, a weakly dissociable alkaloid. As far as we know, this is the first report on experimental logKow data for harmaline (logKow = 2.28 ± 0.08). Introducing neutral compounds into a basic model training set or using neutral model compounds alone is recommended to measure the lipophilicity of weakly ionizable basic compounds especially those with high hydrophobicity for the advantages of more suitable model compound choices and convenient mobile phase pH control.

  7. Developmental neurological effects of dioxin-like compounds -- Relative species sensitivity

    SciTech Connect

    Henshel, D.S.

    1995-12-31

    2,3,7,8-Tetrachlorodibenzo-p-dioxin and related compounds are known to be teratogenic. Studies have shown that in ovo exposure to these compounds causes teratogenic changes in the brain which are manifested as a gross bilateral asymmetry in the forebrain and tectum. Through field and laboratory studies the authors are trying to determine whether this endpoint will be generally useful as a biomarker for dioxin-related developmental effects. The ultimate aim is to use this information to establish toxic equivalents for the developmental neurotoxic effects of TCDD and related compounds. In order to properly establish relative toxic equivalents (the focus of this session), one needs to know both the relative effects of different compounds on a single species, at a single life stage, and the relative effects of similar (preferably the same compounds) on different species. Hatchlings or nestlings of several species (great blue heron, doublecrested cormorants, bald eagle) were used in these studies. The brains were measured, and evaluated for bilateral asymmetry. The difference between the two sides of the brain was correlated to the levels of contaminants in either sibling eggs or in plasma from the same bird. These correlations were determined using a variety of published toxic equivalence schemes based on several different endpoints. In a parallel laboratory study, fertile chicken eggs were injected with known concentrations of TCDD from the start of incubation. The clear dose-response relationship between TCDD concentrations and the degree of asymmetry indicates that at least some of the observed gross brain asymmetry is mediated by TCDD-like activity, thus validating the use of TCDD-based toxic equivalents for this particular endpoint.

  8. Effectiveness of phenolic compounds against citrus green mould.

    PubMed

    Sanzani, Simona M; Schena, Leonardo; Ippolito, Antonio

    2014-08-18

    Stored citrus fruit suffer huge losses because of the development of green mould caused by Penicillium digitatum. Usually synthetic fungicides are employed to control this disease, but their use is facing some obstacles, such public concern about possible adverse effects on human and environmental health and the development of resistant pathogen populations. In the present study quercetin, scopoletin and scoparone--phenolic compounds present in several agricultural commodities and associated with response to stresses--were firstly tested in vitro against P. digitatum and then applied in vivo on oranges cv. Navelina. Fruits were wound-treated (100 µg), pathogen-inoculated, stored and surveyed for disease incidence and severity. Although only a minor (≤13%) control effect on P. digitatum growth was recorded in vitro, the in vivo trial results were encouraging. In fact, on phenolic-treated oranges, symptoms appeared at 6 days post-inoculation (DPI), i.e., with a 2 day-delay as compared to the untreated control. Moreover, at 8 DPI, quercetin, scopoletin, and scoparone significantly reduced disease incidence and severity by 69%-40% and 85%-70%, respectively, as compared to the control. At 14 DPI, scoparone was the most active molecule. Based on the results, these compounds might represent an interesting alternative to synthetic fungicides.

  9. Effectiveness of phenolic compounds against citrus green mould.

    PubMed

    Sanzani, Simona M; Schena, Leonardo; Ippolito, Antonio

    2014-01-01

    Stored citrus fruit suffer huge losses because of the development of green mould caused by Penicillium digitatum. Usually synthetic fungicides are employed to control this disease, but their use is facing some obstacles, such public concern about possible adverse effects on human and environmental health and the development of resistant pathogen populations. In the present study quercetin, scopoletin and scoparone--phenolic compounds present in several agricultural commodities and associated with response to stresses--were firstly tested in vitro against P. digitatum and then applied in vivo on oranges cv. Navelina. Fruits were wound-treated (100 µg), pathogen-inoculated, stored and surveyed for disease incidence and severity. Although only a minor (≤13%) control effect on P. digitatum growth was recorded in vitro, the in vivo trial results were encouraging. In fact, on phenolic-treated oranges, symptoms appeared at 6 days post-inoculation (DPI), i.e., with a 2 day-delay as compared to the untreated control. Moreover, at 8 DPI, quercetin, scopoletin, and scoparone significantly reduced disease incidence and severity by 69%-40% and 85%-70%, respectively, as compared to the control. At 14 DPI, scoparone was the most active molecule. Based on the results, these compounds might represent an interesting alternative to synthetic fungicides. PMID:25153867

  10. Effect on microorganisms of volatile compounds released from germinating seeds.

    PubMed

    Schenck, S; Stotzky, G

    1975-10-01

    Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A. radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f. conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune. Spores of Trichoderma viride showed higher germination in the presence of volatiles. Effects on growth were apparent only during the first 3 or 4 days after planting the seeds. Killed or dried seeds had no effect. The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors. Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, primarily aldehydes, were the active components. The volatiles were not absorbed by sterile soil, clay minerals, or water, but they were absorbed by non-steril soil and activated charcoal.

  11. Determination of total sulfur compounds and benzothiazole in asphalt fume samples by gas chromatography with sulfur chemiluminescence detection.

    PubMed

    Jaycox, L B; Olsen, L D

    2000-09-01

    As part of a collaborative project between the National Institute for Occupational Safety and Health and the Federal Highway Administration to evaluate asphalt pavers' exposures to asphalt fume and their potential health effects, a method was developed for the determination of total sulfur compounds and benzothiazole in asphalt fume samples. Asphalt fume samples were collected from asphalt mixtures with and without the addition of ground-up rubber tires. The asphalt fume samples were collected with sampling trains that consisted of a Teflon membrane filter and an XAD-2 adsorbent tube. Filter and sampling tube media were extracted with hexane and subsequently analyzed by gas chromatography with a sulfur chemiluminescence detector. Separation was achieved with a 100 percent dimethyl polysiloxane fused silica column. Typical calibration curves had linear correlation coefficients of 0.99 or better with a relative standard deviation (RSD) of 5 percent. Benzothiazole desorption efficiency (DE) determined using spiked sampling tubes ranged from 96.5 percent at 5.0 micrograms to 89.4 percent at 40 micrograms with RSD values from 0.9 to 4.0 percent. Benzothiazole storage recovery determined using sampling tubes spiked at 20 micrograms and refrigerated for 30 days at 4 degrees C was 89.8 percent when corrected for the DE with an RSD of 1.1 percent. The limit of detection for the method determined using spiked sampling tubes was 0.30 microgram. Quantitation for total sulfur compounds and benzothiazole was against benzothiazole standards in hexane. Because of detector selectivity, sample preparation consisted of a simple hexane extraction even when samples had a high background due to hydrocarbon overload. Detector sensitivity provided quantitation in the sub-microgram region. Because of the sample preparation step and because benzothiazole was determined during the same analysis run, this method is straightforward and analytically efficient. The method has been used to

  12. Determination of Wastewater Compounds in Whole Water by Continuous Liquid-Liquid Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry

    USGS Publications Warehouse

    Zaugg, Steven D.; Smith, Steven G.; Schroeder, Michael P.

    2006-01-01

    A method for the determination of 69 compounds typically found in domestic and industrial wastewater is described. The method was developed in response to increasing concern over the impact of endocrine-disrupting chemicals on aquatic organisms in wastewater. This method also is useful for evaluating the effects of combined sanitary and storm-sewer overflow on the water quality of urban streams. The method focuses on the determination of compounds that are indicators of wastewater or have endocrine-disrupting potential. These compounds include the alkylphenol ethoxylate nonionic surfactants, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Wastewater compounds in whole-water samples were extracted using continuous liquid-liquid extractors and methylene chloride solvent, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-water samples fortified at 0.5 microgram per liter averaged 72 percent ? 8 percent relative standard deviation. The concentration of 21 compounds is always reported as estimated because method recovery was less than 60 percent, variability was greater than 25 percent relative standard deviation, or standard reference compounds were prepared from technical mixtures. Initial method detection limits averaged 0.18 microgram per liter. Samples were preserved by adding 60 grams of sodium chloride and stored at 4 degrees Celsius. The laboratory established a sample holding-time limit prior to sample extraction of 14 days from the date of collection.

  13. Effect of bedding materials on concentration of odorous compounds and Escherichia coli in beef cattle bedded manure packs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine the effect of bedding material (corn stover, soybean stover, wheat straw, switchgrass, wood chips, wood shavings, corn cobs, and shredded paper) on concentration of odorous volatile organic compounds (VOC) in bedded pack material, and to determine the e...

  14. Determination of sulfur and nitrogen compounds during the processing of dry fermented sausages and their relation to amino acid generation.

    PubMed

    Corral, Sara; Leitner, Erich; Siegmund, Barbara; Flores, Mónica

    2016-01-01

    The identification of odor-active sulfur and nitrogen compounds formed during the processing of dry fermented sausages was the objective of this study. In order to elucidate their possible origin, free amino acids (FAAs) were also determined. The volatile compounds present in the dry sausages were extracted using solvent assisted flavor evaporation (SAFE) and monitored by one and two-dimensional gas chromatography with different detectors: mass spectrometry (MS), nitrogen phosphorous (NPD), flame photometric (FPD) detectors, as well as gas chromatography-olfactometry. A total of seventeen sulfur and nitrogen compounds were identified and quantified. Among them, 2-acetyl-1-pyrroline was the most potent odor active compound, followed by methional, ethylpyrazine and 2,3-dihydrothiophene characterized by toasted, cooked potato, and nutty notes. The degradation of FAAs, generated during processing, was related to the production of aroma compounds, such as methionine forming methional and benzothiazole while ornithine was the precursor compound for 2-acetyl-1-pyrroline and glycine for ethylpyrazine.

  15. Effects of elastic anisotropy on mechanical behavior of intermetallic compounds

    SciTech Connect

    Yoo, M.H.

    1991-01-01

    Fundamental aspects of the deformation and fracture behavior of ordered intermetallic compounds are examined within the framework of linear anisotropic elasticity theory of dislocations and cracks. The orientation dependence and the tension/compression asymmetry of yield stress are explained in terms of the anisotropic coupling effect of non-glide stresses to the glide strain. The anomalous yield behavior is related to the disparity (edge/screw) of dislocation mobility and the critical stress required for the dislocation multiplication mechanism of Frank-Read type. The slip-twin conjugate relationship, extensive faulting, and pseudo-twinning (martensitic transformation) at a crack tip can be enhanced also by the anisotropic coupling effect, which may lead to transformation toughening of shear type.

  16. In vitro effects of boron-containing compounds upon glioblastoma cells.

    PubMed

    Bailey, S F; Kabalka, G W; Fuhr, J E

    1997-12-01

    Boron-neutron capture therapy (BNCT) is currently under investigation as a novel therapeutic modality for glioblastoma. This study was undertaken to determine whether boron-containing compounds 4-borono-2-fluoro-D,L-phenylalanine (FBPA) and FBPA-fructose have direct effects upon kinetics of A172, a glioblastoma cell line. Flow cytometry analyzed cell-cycle distribution and S-phase kinetics (bromo deoxyuridine [BUdR] incorporation). BUdR incorporation was increased during a 1-hr pulse after 24-hr or 72-hr exposure of cells to varying concentrations of FBPA or FBPA-fructose. Results suggest that boron-containing compounds may effect cell kinetics apart from neutron activation, and this effect should be further evaluated for potential impact upon tumor responsiveness to BNCT.

  17. Compounds Released from Biomass Deconstruction: Understanding Their Effect on Cellulose Enzyme Hydrolysis and Their Biological Activity

    NASA Astrophysics Data System (ADS)

    Djioleu, Angele Mezindjou

    The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in the presence of switchgrass prehydrolyzates against model substrates, activities of cellulase, betaglucosidase, and exoglucanase, were significantly reduced by at least 16%, 31.8%, and 57.8%, respectively, as compared to the control. A strong positive correlation between inhibition of betaglucosidase and concentration of glucose, acetic acid, and furans in prehydrolyzate was established. Exoglucanase inhibition correlated with the presence of phenolic compounds and acetic acid. The prehydrolyzate, prepared at 160°C, 30 min, and 1% acid, was fractionated by centrifugal partition chromatography (CPC) into six fractions; the inhibition effect of these fractions on betaglucosidase and exoglucanase was determined. The initial hydrolysis rate of cellobiose by betaglucosidase was significantly reduced by the CPC sugar-rich fraction; however, exoglucanase was deactivated by the CPC phenolic-rich fraction. Finally, biological activities of water-extracted compounds from sweetgum bark and their effect on cellulase was investigated. It was determined that 12% of solid content of the bark extract could be accounted by phenolic compounds with gallic acid identified as the most concentrated phytochemical. Sweetgum bark extract inhibited Staphylococcus

  18. Determination of urban volatile organic compound emission ratios and comparison with an emissions database

    NASA Astrophysics Data System (ADS)

    Warneke, C.; McKeen, S. A.; de Gouw, J. A.; Goldan, P. D.; Kuster, W. C.; Holloway, J. S.; Williams, E. J.; Lerner, B. M.; Parrish, D. D.; Trainer, M.; Fehsenfeld, F. C.; Kato, S.; Atlas, E. L.; Baker, A.; Blake, D. R.

    2007-05-01

    During the NEAQS-ITCT2k4 campaign in New England, anthropogenic VOCs and CO were measured downwind from New York City and Boston. The emission ratios of VOCs relative to CO and acetylene were calculated using a method in which the ratio of a VOC with acetylene is plotted versus the photochemical age. The intercept at the photochemical age of zero gives the emission ratio. The so determined emission ratios were compared to other measurement sets, including data from the same location in 2002, canister samples collected inside New York City and Boston, aircraft measurements from Los Angeles in 2002, and the average urban composition of 39 U.S. cities. All the measurements generally agree within a factor of two. The measured emission ratios also agree for most compounds within a factor of two with vehicle exhaust data indicating that a major source of VOCs in urban areas is automobiles. A comparison with an anthropogenic emission database shows less agreement. Especially large discrepancies were found for the C2-C4 alkanes and most oxygenated species. As an example, the database overestimated toluene by almost a factor of three, which caused an air quality forecast model (WRF-CHEM) using this database to overpredict the toluene mixing ratio by a factor of 2.5 as well. On the other hand, the overall reactivity of the measured species and the reactivity of the same compounds in the emission database were found to agree within 30%.

  19. New β-Cyclodextrin Entrapped in Polyethyleneimine Film-Modified Electrodes for Pharmaceutical Compounds Determination

    PubMed Central

    Fritea, Luminţa; Tertiş, Mihaela; Cristea, Cecilia; Săndulescu, Robert

    2013-01-01

    The electrochemical behavior of ascorbic acid and uric acid on glassy carbon bare electrodes and ones modified with β-cyclodextrin entrapped in polyethyleneimine film has been investigated using square wave voltammetry. The electrode modification was achieved in order to separate the voltammetric peaks of ascorbic acid and uric acid when present in the same solution. On the modified electrodes the potential of the oxidation peak of the ascorbic acid was shifted to more negative values by over 0.3 V, while in the case of uric acid, the negative potential shift was about 0.15 V compared to the bare glassy carbon electrode. When the two compounds were found together in the solution, on the bare electrode only a single broad signal was observed, while on the modified electrode the peak potentials of these two compounds were separated by 0.4 V. When the uric acid concentration remained constant, the peak intensity of the ascorbic acid is increased linearly with the concentration (r2 = 0.996) and when the ascorbic acid concentration remains constant, the peak intensity of the uric acid increased linearly with the concentration (r2 = 0.992). FTIR measurements supported the formation of inclusion complexes. In order to characterize the modification of the electrodes microscopic studies were performed. The modified electrodes were successfully employed for the determination of ascorbic acid in pharmaceutical formulations with a detection limit of 0.22 μM. PMID:24287544

  20. Microemulsion electrokinetic chromatography as a suitable tool for lipophilicity determination of acidic, neutral, and basic compounds.

    PubMed

    Subirats, Xavier; Yuan, Hui-Ping; Chaves, Verónica; Marzal, Núria; Rosés, Martí

    2016-07-01

    In the present work, several MEEKC systems are studied to assess their suitability for lipophilicity determination of acidic, neutral, and basic compounds. Thus, several microemulsion compositions over a wide range of pH values (from 2.0 to 12.0), containing heptane, 1-butanol and different types and amounts of surfactant (SDS or sodium cholate: from 1.3 to 3.3%) are characterized using Abraham's solvation model. The addition of acetonitrile (up to 10%) is also studied, since it increases the resolution of the technique for the most lipophilic compounds. The system coefficients obtained are very similar to those of the 1-octanol/water, used as the reference lipophilicity index, allowing simple and linear correlations between the 1-octanol/water partition values (log Po/w ) and MEEKC mass distribution ratios (log kMEEKC ). Variations in the microemulsion composition (aqueous buffer, surfactant, concentration of ACN) did not significantly affect the similarity of the MEEKC systems to log Po/w partition.

  1. Microemulsion electrokinetic chromatography as a suitable tool for lipophilicity determination of acidic, neutral, and basic compounds.

    PubMed

    Subirats, Xavier; Yuan, Hui-Ping; Chaves, Verónica; Marzal, Núria; Rosés, Martí

    2016-07-01

    In the present work, several MEEKC systems are studied to assess their suitability for lipophilicity determination of acidic, neutral, and basic compounds. Thus, several microemulsion compositions over a wide range of pH values (from 2.0 to 12.0), containing heptane, 1-butanol and different types and amounts of surfactant (SDS or sodium cholate: from 1.3 to 3.3%) are characterized using Abraham's solvation model. The addition of acetonitrile (up to 10%) is also studied, since it increases the resolution of the technique for the most lipophilic compounds. The system coefficients obtained are very similar to those of the 1-octanol/water, used as the reference lipophilicity index, allowing simple and linear correlations between the 1-octanol/water partition values (log Po/w ) and MEEKC mass distribution ratios (log kMEEKC ). Variations in the microemulsion composition (aqueous buffer, surfactant, concentration of ACN) did not significantly affect the similarity of the MEEKC systems to log Po/w partition. PMID:27126602

  2. [Rapid determination of aspartame in compound sweetening by reversed-phase high performance liquid chromatography].

    PubMed

    Zhang, R; Jiang, M

    1997-11-01

    A method for rapid determination of Aspartame in compound sweetening by reversed-phase high performance liquid chromatography is presented. Aspartame in compound sweetening was separated in a short column (Ultrasphere XL-ODS, 3 microm, 4.6 mm x 70 mm) by using CH3OH-0.02 mol/L NH4Ac as mobile phase. The flow rate was 0.8 mL/min. Detection was performed with UV detector at 220 nm. The injection volume was 20 microL. It was qualitatively analysed by UV scanning at a wavelength range of 200-350 nm under no-stop flow according to their retention time. Quantitative analysis was carried out by measuring peak height and comparing it with external standard. The minimum detectable amount was 5 microg/L. The linear range of the calibration curve was 40-200 mg/L. The average recovery of Aspartame was 92%. The relative standard deviation was 2.9%. This method is simple, rapid and sensitive.

  3. Identification of estrogenic compounds in oil sands process waters by effect directed analysis.

    PubMed

    Yue, Siqing; Ramsay, Bruce A; Brown, R Stephen; Wang, Jiaxi; Ramsay, Juliana A

    2015-01-01

    Using effect directed analysis, the presence of estrogenic components in untreated and biologically treated oil sands process water (OSPW) was detected with the yeast estrogenic screening assay after fractionation with solid phase extraction followed by reversed phase high performance liquid chromatography. Comparison of the composition, as determined by electrospray ionization combined with high-resolution linear trap quadropole (LTQ)-Orbitrap Velos Pro hybrid mass spectrometry (negative ion) of selected estrogenic and nonestrogenic fractions identified compounds that were uniquely present in the estrogenic samples, biologically treated and untreated. Of the 30 most abundant compounds, there were 14 possible nonaromatic structures and 16 possible aromatic structures. Based on the published literature, the latter are the most likely to cause estrogenicity and were O2, O3 and O4 C17 to C20 compounds with double bond equivalents between 6 and 10 and chemical formulas similar to estrone- and estradiol-like compounds. This study shows exact formulas and masses of possible estrogenic compounds in OSPW. These findings will help to focus study on the most environmentally significant components in OSPW.

  4. Identification of estrogenic compounds in oil sands process waters by effect directed analysis.

    PubMed

    Yue, Siqing; Ramsay, Bruce A; Brown, R Stephen; Wang, Jiaxi; Ramsay, Juliana A

    2015-01-01

    Using effect directed analysis, the presence of estrogenic components in untreated and biologically treated oil sands process water (OSPW) was detected with the yeast estrogenic screening assay after fractionation with solid phase extraction followed by reversed phase high performance liquid chromatography. Comparison of the composition, as determined by electrospray ionization combined with high-resolution linear trap quadropole (LTQ)-Orbitrap Velos Pro hybrid mass spectrometry (negative ion) of selected estrogenic and nonestrogenic fractions identified compounds that were uniquely present in the estrogenic samples, biologically treated and untreated. Of the 30 most abundant compounds, there were 14 possible nonaromatic structures and 16 possible aromatic structures. Based on the published literature, the latter are the most likely to cause estrogenicity and were O2, O3 and O4 C17 to C20 compounds with double bond equivalents between 6 and 10 and chemical formulas similar to estrone- and estradiol-like compounds. This study shows exact formulas and masses of possible estrogenic compounds in OSPW. These findings will help to focus study on the most environmentally significant components in OSPW. PMID:25521156

  5. Fish embryo toxicity test: identification of compounds with weak toxicity and analysis of behavioral effects to improve prediction of acute toxicity for neurotoxic compounds.

    PubMed

    Klüver, Nils; König, Maria; Ortmann, Julia; Massei, Riccardo; Paschke, Albrecht; Kühne, Ralph; Scholz, Stefan

    2015-06-01

    The fish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, but concerns have been raised for its predictivity given that a few compounds have been shown to exhibit a weak acute toxicity in the fish embryo. In order to better define the applicability domain and improve the predictive capacity of the fish embryo test, we performed a systematic analysis of existing fish embryo and acute fish toxicity data. A correlation analysis of a total of 153 compounds identified 28 compounds with a weaker or no toxicity in the fish embryo test. Eleven of these compounds exhibited a neurotoxic mode of action. We selected a subset of eight compounds with weaker or no embryo toxicity (cyanazine, picloram, aldicarb, azinphos-methyl, dieldrin, diquat dibromide, endosulfan, and esfenvalerate) to study toxicokinetics and a neurotoxic mode of action as potential reasons for the deviating fish embryo toxicity. Published fish embryo LC50 values were confirmed by experimental analysis of zebrafish embryo LC50 according to OECD guideline 236. Except for diquat dibromide, internal concentration analysis did not indicate a potential relation of the low sensitivity of fish embryos to a limited uptake of the compounds. Analysis of locomotor activity of diquat dibromide and the neurotoxic compounds in 98 hpf embryos (exposed for 96 h) indicated a specific effect on behavior (embryonic movement) for the neurotoxic compounds. The EC50s of behavior for neurotoxic compounds were close to the acute fish toxicity LC50. Our data provided the first evidence that the applicability domain of the fish embryo test (LC50s determination) may exclude neurotoxic compounds. However, neurotoxic compounds could be identified by changes in embryonic locomotion. Although a quantitative prediction of acute fish toxicity LC50 using behavioral assays in fish embryos may not yet be possible, the identification of neurotoxicity could trigger the conduction of a conventional fish

  6. Anti-inflammatory effects of phenolic compounds isolated from the fruits of Artocarpus heterophyllus.

    PubMed

    Fang, Song-Chwan; Hsu, Chin-Lin; Yen, Gow-Chin

    2008-06-25

    Artocarpus heterophyllus Lam is a large evergreen tree cultivated throughout Southeast Asia for its fruits. Its leaves and roots have been used for medicinal purposes. The aim of this work was to study the in vitro anti-inflammatory effects of phenolic compounds isolated from the ethyl acetate extracts of the fruits of Artocarpus heterophyllus. Three phenolic compounds were characterized as artocarpesin [5,7,2',4'-tetrahydroxy-6-(3-methylbut-3-enyl) flavone] ( 1), norartocarpetin (5,7,2',4'-tetrahydroxyflavone) ( 2), and oxyresveratrol [ trans-2,4,3',5'-tetrahydroxystilbene] ( 3) by spectroscopic methods and through comparison with data reported in the literatures. The anti-inflammatory effects of the isolated compounds ( 1- 3) were evaluated by determining their inhibitory effects on the production of proinflammatory mediators in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophage cells. These three compounds exhibited potent anti-inflammatory activity. The results indicated that artocarpesin ( 1) suppressed the LPS-induced production of nitric oxide (NO) and prostaglandin E 2 (PGE 2) through the down-regulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expressions. Thus, artocarpesin ( 1) may provide a potential therapeutic approach for inflammation-associated disorders.

  7. Anti-inflammatory effects of phenolic compounds isolated from the fruits of Artocarpus heterophyllus.

    PubMed

    Fang, Song-Chwan; Hsu, Chin-Lin; Yen, Gow-Chin

    2008-06-25

    Artocarpus heterophyllus Lam is a large evergreen tree cultivated throughout Southeast Asia for its fruits. Its leaves and roots have been used for medicinal purposes. The aim of this work was to study the in vitro anti-inflammatory effects of phenolic compounds isolated from the ethyl acetate extracts of the fruits of Artocarpus heterophyllus. Three phenolic compounds were characterized as artocarpesin [5,7,2',4'-tetrahydroxy-6-(3-methylbut-3-enyl) flavone] ( 1), norartocarpetin (5,7,2',4'-tetrahydroxyflavone) ( 2), and oxyresveratrol [ trans-2,4,3',5'-tetrahydroxystilbene] ( 3) by spectroscopic methods and through comparison with data reported in the literatures. The anti-inflammatory effects of the isolated compounds ( 1- 3) were evaluated by determining their inhibitory effects on the production of proinflammatory mediators in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophage cells. These three compounds exhibited potent anti-inflammatory activity. The results indicated that artocarpesin ( 1) suppressed the LPS-induced production of nitric oxide (NO) and prostaglandin E 2 (PGE 2) through the down-regulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expressions. Thus, artocarpesin ( 1) may provide a potential therapeutic approach for inflammation-associated disorders. PMID:18500810

  8. High-performance liquid chromatography determination and pharmacokinetics of coumarin compounds after oral administration of Samul-Tang to rats

    PubMed Central

    Hwang, Youn-Hwan; Cho, Won-Kyung; Jang, Doorye; Ha, Jeong-Ho; Ma, Jin Yeul

    2014-01-01

    Background: Samul-tang has been traditionally used for the treatment of cardiovascular, gynecologic, cutaneous, and chronic inflammation disorders. Although coumarin compounds do have various pharmacological activities and the same may be present in Samul-tang, however there is little information about it. Objective: A simple and sensitive high-performance liquid chromatography (HPLC) method has been developed for the determination of nodakenin, nodakenetin, decursin, decursinol, and decursinol angelate in rat plasma. To obtain a better understanding for pharmacological properties of Samul-tang, pharmacokinetic study of coumarin compounds was performed after oral administration of Samul-tang in rats. Materials and Methods: Chromatographic separation of the analytes was successfully achieved on a Phenomenex Luna C18 column (4.6 mm×250 mm, 5 μm) using a mobile phase composed of acetonitrile water with a gradient elution at a flow rate of 1 mL/min. Noncompartmental analysis was performed. Results: Calibration curves for all analytes had good linearity (r2 <0.999) in a wide linear range. The lower limit of quantification (LLOQ) ranged from 0.05 to 0.1 μg/mL. The variation of intra- and interday assay was less than 15%. Nodakenin, nodakenetin, and decursinol were determined in rat plasma after oral administration of Samul-tang. Conclusion: This developed and validated HPLC method was successfully applied to the pharmacokinetic study of three coumarin compounds in rats, given as a single oral administration of Samul-tang. These pharmacokinetic data of the nodakenin, nodakenetin, and decursinol could offer a new point of view to evaluate the pharmacological effects of Samul-tang. PMID:24696544

  9. Determination of some polyphenolic compounds from Allium species by HPLC-UV-MS.

    PubMed

    Parvu, Marcel; Toiu, Anca; Vlase, Laurian; Alina Parvu, Elena

    2010-09-01

    Five Allium species (Allium obliquum L., A. senescens L. subsp. montanum (Fries) Holub, A. schoenoprasum L. subsp. schoenoprasum, A. fistulosum L. and A. ursinum L.) were analysed in order to determine the presence of 19 polyphenolic compounds through an HPLC method coupled with UV and mass spectrometry detection. The pattern of phenol carboxylic acids indicates the presence of p-coumaric and ferulic acids in all species. Isoquercitrin was found in A. obliquum, A. schoenoprasum and A. fistulosum, rutin in A. senescens subsp. montanum and A. schoenoprasum, whereas quercitrin was found only in A. fistulosum, so they represent potential taxonomic markers that differentiate the four plants. Luteolin and apigenin were identified before and after hydrolysis only in A. obliquum. The amounts of all polyphenols were higher in hydrolysed samples, suggesting that these substances are present both as unbonded and bonded glycosides and/or esters. Our study showed large differences between the five Allium species, both qualitative and quantitative. PMID:20419559

  10. Determination of the Cytostatic and Cytocidal Activities of Antimalarial Compounds and their Combination Interactions

    PubMed Central

    Sherlach, Katy S.; Roepe, Paul D.

    2014-01-01

    Determining the antiplasmodial activity of candidate antimalarial drugs in vitro identifies new therapies for drug-resistant malaria. Importantly though, activity can be either growth-inhibitory (cytostatic) or parasite-kill (cytocidal), or both. The simple methods described here can allow for distinction between these, as well as definition of drug interactions between two or more compounds. The latter is important in the definition of novel drug combination therapy for malaria. These methods involve live malarial parasite red blood cell culture, routine pharmacology, high-throughput detection of parasite DNA with fluorescent reporters, and routine mathematical analysis of dose – response curves. The techniques and approaches are accessible to most laboratories and require minimal special equipment beyond a fluorescent plate reader and tissue culture facilities. PMID:25445179

  11. A proton transfer reaction mass spectrometry based system for determining plant uptake of volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Tani, Akira; Kato, Shungo; Kajii, Yoshizumi; Wilkinson, Michael; Owen, Sue; Hewitt, Nick

    In order to evaluate the contribution that higher plants make to the removal of volatile organic compounds from the atmosphere, a measurement system consisting of a proton transfer reaction mass spectrometer (PTR-MS), CO 2 analyzer, diffusion devise and leaf enclosure was established. The uptake of VOCs by Golden Pothos ( Epipremnum aureum) was investigated. The overall relative error associated with measurements made using this system was <2.2% when a Golden Pothos leaf was exposed to 75-750 ppbv of methyl isobutyl ketone (MIBK). Even at the lowest MIBK concentration, more than 2.2% of the inflowing VOC was lost to the leaf, representing a detectable and positive MIBK uptake rate by the plant. The results of the investigation were compared with a measurement system based on gas chromatography analysis and it was shown that the use of a PTR-MS based system can significantly increase the certainties in determining the rate of VOC uptake by plants.

  12. Ab initio structure determination of new compound Ba 3(BO 3)(PO 4)

    NASA Astrophysics Data System (ADS)

    Ma, H. W.; Liang, J. K.; Wu, L.; Liu, G. Y.; Rao, G. H.; Chen, X. L.

    2004-10-01

    The crystal structure of new compound Ba3BPO7 was determined by ab initio method from high-resolution conventional X-ray powder diffraction data. The Rietveld refinement converged to Rp=5.92%, Rwp=8.87%, Rexp=5.00% with the following details: Hexagonal, space group P63mc, a=5.4898 (1) Å, c=14.7551(1) Å, Z=2. The basic unit of the structure is the [BaO10]-[BO3]-[PO4] polar polyhedra-chain composed of Ba1-B-P-O cluster. These chains, running along c-axis, stack in a HCP mode to build the whole structure with triangular prism channels. The channels are parallel to c-axis too, in which Ba2 and Ba3 are located.

  13. Immunomodulation and anti-inflammatory effects of garlic compounds.

    PubMed

    Arreola, Rodrigo; Quintero-Fabián, Saray; López-Roa, Rocío Ivette; Flores-Gutiérrez, Enrique Octavio; Reyes-Grajeda, Juan Pablo; Carrera-Quintanar, Lucrecia; Ortuño-Sahagún, Daniel

    2015-01-01

    The benefits of garlic to health have been proclaimed for centuries; however, only recently have Allium sativum and its derivatives been proposed as promising candidates for maintaining the homeostasis of the immune system. The complex biochemistry of garlic makes it possible for variations in processing to yield different preparations with differences in final composition and compound proportion. In this review, we assess the most recent experimental results, which indicate that garlic appears to enhance the functioning of the immune system by stimulating certain cell types, such as macrophages, lymphocytes, natural killer (NK) cells, dendritic cells, and eosinophils, by mechanisms including modulation of cytokine secretion, immunoglobulin production, phagocytosis, and macrophage activation. Finally, because immune dysfunction plays an important role in the development and progress of several diseases, we critically examined immunoregulation by garlic extracts and compounds isolated, which can contribute to the treatment and prevention of pathologies such as obesity, metabolic syndrome, cardiovascular disorders, gastric ulcer, and even cancer. We concluded that A. sativum modulates cytokine secretion and that such modulation may provide a mechanism of action for many of their therapeutic effects.

  14. Immunomodulation and Anti-Inflammatory Effects of Garlic Compounds

    PubMed Central

    Arreola, Rodrigo; Quintero-Fabián, Saray; López-Roa, Rocío Ivette; Flores-Gutiérrez, Enrique Octavio; Reyes-Grajeda, Juan Pablo; Carrera-Quintanar, Lucrecia; Ortuño-Sahagún, Daniel

    2015-01-01

    The benefits of garlic to health have been proclaimed for centuries; however, only recently have Allium sativum and its derivatives been proposed as promising candidates for maintaining the homeostasis of the immune system. The complex biochemistry of garlic makes it possible for variations in processing to yield different preparations with differences in final composition and compound proportion. In this review, we assess the most recent experimental results, which indicate that garlic appears to enhance the functioning of the immune system by stimulating certain cell types, such as macrophages, lymphocytes, natural killer (NK) cells, dendritic cells, and eosinophils, by mechanisms including modulation of cytokine secretion, immunoglobulin production, phagocytosis, and macrophage activation. Finally, because immune dysfunction plays an important role in the development and progress of several diseases, we critically examined immunoregulation by garlic extracts and compounds isolated, which can contribute to the treatment and prevention of pathologies such as obesity, metabolic syndrome, cardiovascular disorders, gastric ulcer, and even cancer. We concluded that A. sativum modulates cytokine secretion and that such modulation may provide a mechanism of action for many of their therapeutic effects. PMID:25961060

  15. Fast and simple determination of perfluorinated compounds and their potential precursors in different packaging materials.

    PubMed

    Zabaleta, I; Bizkarguenaga, E; Bilbao, D; Etxebarria, N; Prieto, A; Zuloaga, O

    2016-05-15

    A simple and fast analytical method for the determination of fourteen perfluorinated compounds (PFCs), including three perfluoroalkylsulfonates (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) and ten potential precursors, including four polyfluoroalkyl phosphates (PAPs), four fluorotelomer saturated acids (FTCAs) and two fluorotelomer unsaturated acids (FTUCAs) in different packaging materials was developed in the present work. In order to achieve this objective the optimization of an ultrasonic probe-assisted extraction (UPAE) method was carried out before the analysis of the target compounds by liquid-chromatography-triple quadrupole-tandem mass spectrometry (LC-QqQ-MS/MS). 7 mL of 1 % acetic acid in methanol and a 2.5-min single extraction cycle were sufficient for the extraction of all the target analytes. The optimized analytical method was validated in terms of recovery, precision and method detection limits (MDLs). Apparent recovery values after correction with the corresponding labeled standard were in the 69-103 % and 62-98 % range for samples fortified at 25 ng/g and 50 ng/g concentration levels, respectively and MDL values in the 0.6-2.2 ng/g range were obtained. The developed method was applied to the analysis of plastic (milk bottle, muffin cup, pre-cooked food wrapper and cup of coffee) and cardboard materials (microwave popcorn bag, greaseproof paper for French fries, cardboard box for pizza and cinema cardboard box for popcorn). To the best of our knowledge, this is the first method that describes the determination of fourteen PFCs and ten potential precursors in packaging materials. Moreover, 6:2 FTCA, 6:2 FTUCA and 5:3 FTCA analytes were detected for the first time in microwave popcorn bags. PMID:26992531

  16. On-line strategies for determining trace levels of nitroaromatic explosives and related compounds in water.

    PubMed

    Crescenzi, C; Albiñana, J; Carlsson, H; Holmgren, E; Batlle, R

    2007-06-15

    We report the development and tests of several systems for the simultaneous determination of 18 energetic compounds and related congeners in untreated water samples. In these systems a Restricted Access Material trap or liquid-chromatography precolumn (with a C(18) or porous graphitic carbon, PGC, stationary phase) followed by a PGC analytical column are used for sample clean-up, enrichment and separation of the trace level analytes, which are then analyzed by mass spectrometry (MS). The relative merits of two MS ionization interfaces (atmospheric pressure chemical ionization, APCI, and atmospheric pressure photoionization, APPI) were also compared for the MS identification and quantification of these analytes. APCI was found to be superior in cases where both alternatives are applicable. A major drawback when applying APPI is that no signal is obtained for the cyclic nitramines and nitrate esters. Using APCI, a wide spectrum of unstable compounds can be determined in a single analysis, and the feasibility of using large volume samples (up to 100 mL) in combination with the sensitivity of the MS detection system provide method detection limits ranging from 2.5 pg/mL (for 2,4-dinitrotoluene and 2,6-diamino-6-nitrotoluene) to 563 pg/mL (for pentaerythritol tetranitrate, PETN), with repeatability ranging from 2 to 7%. Other chemometric parameters such as robustness, selectivity, repeatability, and intermediate precision were also evaluated in the validation of the extraction methods for use in water analysis. Tests with untreated groundwater and drinking water samples, spiked with 20 ng of the analytes, yielded results similar to those obtained with high purity water samples.

  17. Fast and simple determination of perfluorinated compounds and their potential precursors in different packaging materials.

    PubMed

    Zabaleta, I; Bizkarguenaga, E; Bilbao, D; Etxebarria, N; Prieto, A; Zuloaga, O

    2016-05-15

    A simple and fast analytical method for the determination of fourteen perfluorinated compounds (PFCs), including three perfluoroalkylsulfonates (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) and ten potential precursors, including four polyfluoroalkyl phosphates (PAPs), four fluorotelomer saturated acids (FTCAs) and two fluorotelomer unsaturated acids (FTUCAs) in different packaging materials was developed in the present work. In order to achieve this objective the optimization of an ultrasonic probe-assisted extraction (UPAE) method was carried out before the analysis of the target compounds by liquid-chromatography-triple quadrupole-tandem mass spectrometry (LC-QqQ-MS/MS). 7 mL of 1 % acetic acid in methanol and a 2.5-min single extraction cycle were sufficient for the extraction of all the target analytes. The optimized analytical method was validated in terms of recovery, precision and method detection limits (MDLs). Apparent recovery values after correction with the corresponding labeled standard were in the 69-103 % and 62-98 % range for samples fortified at 25 ng/g and 50 ng/g concentration levels, respectively and MDL values in the 0.6-2.2 ng/g range were obtained. The developed method was applied to the analysis of plastic (milk bottle, muffin cup, pre-cooked food wrapper and cup of coffee) and cardboard materials (microwave popcorn bag, greaseproof paper for French fries, cardboard box for pizza and cinema cardboard box for popcorn). To the best of our knowledge, this is the first method that describes the determination of fourteen PFCs and ten potential precursors in packaging materials. Moreover, 6:2 FTCA, 6:2 FTUCA and 5:3 FTCA analytes were detected for the first time in microwave popcorn bags.

  18. Multiclass semi-volatile compounds determination in wine by gas chromatography accurate time-of-flight mass spectrometry.

    PubMed

    Rodríguez-Cabo, T; Rodríguez, I; Ramil, M; Silva, A; Cela, R

    2016-04-15

    The performance of gas chromatography (GC) with accurate, high resolution mass spectrometry (HRMS) for the determination of a group of 39 semi-volatile compounds related to wine quality (pesticide residues, phenolic off-flavours, phenolic pollutants and bioactive stilbenes) is investigated. Solid-phase extraction (SPE) was used as extraction technique, previously to acetylation (phenolic compounds) and dispersive liquid-liquid microextraction (DLLME) concentration. Compounds were determined by GC coupled to a quadrupole time-of-flight (QTOF) MS system through an electron ionization (EI) source. The final method attained limits of quantification (LOQs) at the very low ng mL(-1) level, covering the range of expected concentrations for target compounds in red and white wines. For 38 out of 39 compounds, performance of sample preparation and determination steps were hardly affected by the wine matrix; thus, accurate recoveries were achieved by using pseudo-external calibration. Levels of target compounds in a set of 25 wine samples are reported. The capabilities of the described approach for the post-run identification of species not considered during method development, without retention time information, are illustrated and discussed with selected examples of compounds from different classes.

  19. Estrogenic effects of marijuana smoke condensate and cannabinoid compounds

    SciTech Connect

    Lee, Soo Yeun; Oh, Seung Min; Chung, Kyu Hyuck . E-mail: khchung@skku.edu

    2006-08-01

    Chronic exposure to marijuana produces adverse effects on the endocrine and reproductive systems in humans; however, the experimental evidence for this presented thus far has not been without controversy. In this study, the estrogenic effect of marijuana smoke condensate (MSC) was evaluated using in vitro bioassays, viz., the cell proliferation assay, the reporter gene assay, and the ER competitive binding assay. The results of these assays were compared with those of three major cannabinoids, i.e., THC, CBD, and CBN. The estrogenic effect of MSC was further confirmed by the immature female rat uterotrophic assay. MSC stimulated the estrogenicity related to the ER-mediated pathway, while neither THC, CBD, nor CBN did. Moreover, treatment with 10 and 25 mg/kg MSC induced significant uterine response, and 10 mg/kg MSC resulted in an obvious change in the uterine epithelial cell appearance. MSC also enhanced the IGFBP-1 gene expression in a dose-dependent manner. To identify the constituents of MSC responsible for its estrogenicity, the MSC fractionated samples were examined using another cell proliferation assay, and the estrogenic active fraction was analyzed using GC-MS. In the organic acid fraction that showed the strongest estrogenic activity among the seven fractions of MSC, phenols were identified. Our results suggest that marijuana abuse is considered an endocrine-disrupting factor. Furthermore, these results suggest that the phenolic compounds contained in MSC play a role in its estrogenic effect.

  20. Anticancer Effect of AntiMalarial Artemisinin Compounds

    PubMed Central

    Das, AK

    2015-01-01

    The anti-malarial drug artemisinin has shown anticancer activity in vitro and animal experiments, but experience in human cancer is scarce. However, the ability of artemisinins to kill cancer cells through a variety of molecular mechanisms has been explored. A PubMed search of about 127 papers on anti-cancer effects of antimalarials has revealed that this class of drug, including other antimalarials, have several biological characteristics that include anticancer properties. Experimental evidences suggest that artemisinin compounds may be a therapeutic alternative in highly aggressive cancers with rapid dissemination, without developing drug resistance. They also exhibit synergism with other anticancer drugs with no increased toxicity toward normal cells. It has been found that semisynthetic artemisinin derivatives have much higher antitumor activity than their monomeric counterparts via mechanisms like apoptosis, arrest of cell cycle at G0/G1, and oxidative stress. The exact mechanism of activation and molecular basis of these anticancer effects are not fully elucidated. Artemisinins seem to regulate key factors such as nuclear factor-kappa B, survivin, NOXA, hypoxia-inducible factor-1α, and BMI-1, involving multiple pathways that may affect drug response, drug interactions, drug resistance, and associated parameters upon normal cells. Newer synthetic artemisinins have been developed showing substantial antineoplastic activity, but there is still limited information regarding the mode of action of these synthetic compounds. In view of the emerging data, specific interactions with established chemotherapy need to be further investigated in different cancer cells and their phenotypes and validated further using different semisynthetic and synthetic artemisinin derivatives. PMID:25861527

  1. A MIXTURE OF SEVEN ANTIANDROGENIC COMPOUNDS ELICITS ADDITIVE EFFECTS ON THE MALE RAT REPRODUCTIVE TRACT THAT CORRESPOND TO MODELED PREDICTIONS

    EPA Science Inventory

    The main objectives of this study were to: (1) determine whether dissimilar antiandrogenic compounds display additive effects when present in combination and (2) to assess the ability of modelling approaches to accurately predict these mixture effects based on data from single ch...

  2. Evaluation of the Effect of Two Volatile Organic Compounds on Barley Pathogens.

    PubMed

    Kaddes, Amine; Parisi, Olivier; Berhal, Chadi; Ben Kaab, Sofiene; Fauconnier, Marie-Laure; Nasraoui, Bouzid; Jijakli, M Haissam; Massart, Sébastien; De Clerck, Caroline

    2016-08-26

    This study aimed to determine the effect of Volatile Organic Compounds (VOCs) on some pathogens, these VOCs were emitted during interactions of barley with Fusarium culmorum Schltdl and/or Cochliobolus sativus Shoemaker, two common root rot pathogens. Our work shows that two organic esters: methyl propanoate (MP) and methyl prop-2-enoate (MA) significantly reduced the development of fungi in vitro. Additional tests showed that the esters significantly inhibited spore germination of these pathogens. The activity of these VOCs on a wide range of fungal and bacterial pathogens was also tested in vitro and showed inhibitory action. The effect of the VOCs on infected barley seeds also showed plantlets growing without disease symptoms. MA and MP seem to have potential value as alternative plant protection compounds against barley bioagressors.

  3. Evaluation of the Effect of Two Volatile Organic Compounds on Barley Pathogens.

    PubMed

    Kaddes, Amine; Parisi, Olivier; Berhal, Chadi; Ben Kaab, Sofiene; Fauconnier, Marie-Laure; Nasraoui, Bouzid; Jijakli, M Haissam; Massart, Sébastien; De Clerck, Caroline

    2016-01-01

    This study aimed to determine the effect of Volatile Organic Compounds (VOCs) on some pathogens, these VOCs were emitted during interactions of barley with Fusarium culmorum Schltdl and/or Cochliobolus sativus Shoemaker, two common root rot pathogens. Our work shows that two organic esters: methyl propanoate (MP) and methyl prop-2-enoate (MA) significantly reduced the development of fungi in vitro. Additional tests showed that the esters significantly inhibited spore germination of these pathogens. The activity of these VOCs on a wide range of fungal and bacterial pathogens was also tested in vitro and showed inhibitory action. The effect of the VOCs on infected barley seeds also showed plantlets growing without disease symptoms. MA and MP seem to have potential value as alternative plant protection compounds against barley bioagressors. PMID:27571054

  4. Determination of selected cardiovascular active compounds in environmental aquatic samples--Methods and results, a review of global publications from the last 10 years.

    PubMed

    Stankiewicz, Albert; Giebułtowicz, Joanna; Stankiewicz, Urszula; Wroczyński, Piotr; Nałęcz-Jawecki, Grzegorz

    2015-11-01

    In recent years cardiovascular diseases were the second most common cause of death worldwide. Therefore, the consumption of cardiovascular drugs is high, which might result in an increase of them in the environment. The major source of aquatic environmental contamination is still effluents of wastewater treatment plants (WWTPs). Unfortunately removal of cardiovascular active compounds and/or their metabolites in WWTP is still unsatisfactory. Among microbial and abiotic degradation of these compounds during wastewater processes, photolysis and photodegradation of cardiovascular drugs also play an important role. New formed compounds may be more toxic or retain the properties of parent compounds. Thus the main goal of this paper was to provide a detailed and comprehensive review of used analytical methods, coupled to liquid chromatography-tandem mass spectrometry, to determine the presence of cardiovascular compounds in surface waters as well as WTTPs effluents and influents. Exhaustive preparation for mass spectrometry detection and quantitation including samples pre-treatment, and the common problem of the matrix effect are thoroughly explored in this paper. Additionally, the article provides some hints in respect of recently noted problematic issue related to the availability of specific standards for the analysis of drug's metabolites. Furthermore, information concerning the metabolism of cardiovascular active compounds including differences in metabolism within enantiomers is described. This article also touches on the problems associated with environmental risk assessment due to the presence of cardiovasculars in the environment. The paper also tries to explain differences in concentrations among cardiovascular compounds between countries worldwide.

  5. Development and field validation of a new diffusive sampler for determination of atmospheric volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Özden Üzmez, Özlem; Gaga, Eftade O.; Döğeroğlu, Tuncay

    2015-04-01

    A tailor-made diffusive sampler was developed for the determination of atmospheric Volatile Organic Compounds (VOCs) and the validation of the sampler was carried out under field conditions. All parts of the diffusive sampler which are reusable after a proper cleaning process were made of plastic material (delrin). The reusability of the sampler brings an important advantage considering its lower cost. Activated carbon was used as adsorbent and VOCs adsorbed on the activated carbon were analyzed by GC-MS (gas chromatography equipped with mass selective detector). A comprehensive validation study including detection limit, precision, bias, recovery, self-consistency, shelf life, storage stability, reusability was carried out in accordance with the related European standards ((EN) 13528-1 (2000) and 13528-2 (2000)). Also, a comparison was performed with some commercial diffusive samplers such as 3 M OVM 3500 and Radiello to test the performance of the new diffusive sampler in different environments such as urban area and road tunnel. Uptake rates for the measured VOCs were determined and they were evaluated together with the meteorological parameters (temperature, humidity, wind speed). According to the validation results; all the parameters evaluated for the sampler comply with the related standards and this is an indication of the reliability of the sampler for the sampling of VOCs in the atmosphere.

  6. [Determination of organotin compounds in textile auxiliaries by gas chromatography-mass spectrometry].

    PubMed

    Li, Yanming; Hu, Yongjie; Liu, Jinhua; Guo, Yuliang; Wang, Guiqin

    2011-04-01

    A gas chromatography-mass spectrometry (GC-MS) method has been developed for the determination of dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPhT) in textile auxiliaries. The sample was first extracted with n-hexane in acetate buffer solution (pH 4.0) under ultrasonication (for hydrophobic sample) or oscillation extraction (for hydrophilic sample) and then derivatized with sodium tetraethylborate in tetrahydrofuran. The derivative was determined by GC-MS in selected ion monitoring (SIM) mode. The separation and quantification were achieved using a Rxi-5 ms silica capillary column (30 m x 0.25 mm x 0.25 microm). The linear ranges were 0.1-8.0 mg/L for both DBT and TBT, and 0.1-4.0 mg/L for TPhT. There were good linear relationships between the peak area and concentration in the linear ranges and the correlation coefficients (r2) were 0.9994-0.9998. The detection limits (LOD) were from 0.003 mg/L to 0.005 mg/L. The average recoveries of these organotin compounds at the three spiked levels of 4.0, 10.0 and 40.0 mg/kg were 92.6%-108.0% with the relative standard deviations (RSDs) of 2.5%-10.2%. The method is simple and accurate for simultaneous analysis of the DBT, TBT and TPhT in textile auxiliaries.

  7. Comparative study of ecotoxicological effect of triorganotin compounds on various biological subjects.

    PubMed

    Fargasová, A

    1997-02-01

    The toxic and inhibitory effect of 10 triorganotin compounds (triphenlyl-, tribenzyl-, and tributyltins) were determined under standardized conditions on four biological subjects: Tubifex tubifex, Chironomus plumosus, Sinapis alba seeds, and the alga Scenedesmus quadricauda. Observed were the mortality of T. tubifex and Ch. plumosus after 96 hr, the root growth inhibition of S. alba seeds after 72 hr, and the inhibition of growth, photosynthesis, and chlorophyll a content of S. quadricauda after 12 days of cultivation. The effect of triorganotins was expressed as LC50 values for mortality and EC50 values for inhibition. For each subject and observed parameter the rank order of toxicity/or inhibition was arranged.

  8. Effects of Glyphosate on Metabolism of Phenolic Compounds

    PubMed Central

    Duke, Stephen O.; Hoagland, Robert E.; Elmore, C. Dennis

    1980-01-01

    The phenylalanine ammonia-lyase (PAL) inhibitor l-α-aminooxy-β-phenylpropionic acid (AOPP) was root-fed to light-exposed soybean seedlings alone or with glyphosate [N-(phosphonomethyl)glycine] to test further the hypothesis that PAL activity is involved in the mode of action of glyphosate. Extractable PAL activity was increased by 0.01 and 0.1 millimolar AOPP. AOPP reduced total soluble hydroxyphenolic compound levels and increased phenylalanine and tyrosine levels, indicating that in vivo PAL activity was inhibited by AOPP. The increase in extractable PAL caused by AOPP may be a result of decreased feedback inhibition of PAL synthesis by cinnamic acid and/or its derivatives. AOPP alone had no effect on growth (fresh weight and elongation) at either concentration, but at 0.1 millimolar it slightly alleviated growth (fresh weight) inhibition caused by 0.5 millimolar glyphosate after 4 days. Reduction of the free pool of phenylalanine by glyphosate was reversed by AOPP. These results indicate that glyphosate exerts some of its effects through reduction of aromatic amino acid pools through increases in PAL activity and that not all growth effects of glyphosate are due to reductions of aromatic amino acids. PMID:16661135

  9. Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples.

    PubMed

    Sulej, Anna Maria; Polkowska, Żaneta; Astel, Aleksander; Namieśnik, Jacek

    2013-12-15

    The purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination of PAHs, benzotriazoles and glycols is sample preparation stage, due to diverse matrix composition, the possibility of interference associated with the presence of components with similar physicochemical properties. In this study, five different versions of sample preparation using extraction techniques, such as: LLE and SPE, were tested. In all examined runoff water samples collected from the airports, the presence of PAH compounds and glycols was observed. In majority of the samples, BT compounds were determined. Runoff water samples collected from the areas of Polish and British international airports as well as local airports had similar qualitative composition, but quantitative composition of the analytes was very diverse. New and validated analytical methodologies ensure that the necessary information for assessing the negative impact of airport activities on the environment can be obtained.

  10. Cooperative water-SOM interactions derived from the organic compound effect on SOM hydration

    NASA Astrophysics Data System (ADS)

    Borisover, Mikhail

    2014-05-01

    Interactions of water molecules with soil organic matter (SOM) may affect the ability of SOM to participate in multiple physical, chemical and biological processes. Specifically, water-SOM interactions may have a profound effect on interactions of organic compounds with SOM which is often considered as a major natural sorbent controlling the environmental fate of organic pollutants in the soil environment. Quantification of water - SOM interactions may be carried out by using water vapor sorption isotherms. However, water sorption isotherms providing macroscopic thermodynamic data do not allow examining water-SOM interactions on a microenvironment scale. The examination of water-SOM interactions in a local SOM environment may be carried out by determining the response of the SOM hydration to sorption of probe organic compounds. Recently, the model-free approach was proposed which allows quantifying effects of sorbing organic molecules on water - SOM interactions, by using relatively more available data on the effect of water activity on organic compound - SOM interactions. Therefore, this thermodynamic approach was applied to the experimental data describing sorption of organic compounds by SOM, both from the vapor and liquid phases, at various water activities. Hence, the response of water interactions with the model SOM materials such as a humic acid and an organic matter-rich peat soil to the presence of various organic sorbates was evaluated. Depending on a molecular structure of organic sorbates probing various molecular environments in SOM, the SOM-bound water may be driven in or out of the SOM sorbents. Organic compounds containing the atoms of oxygen, nitrogen or sulfur and preferring a relatively "polar" SOM microenvironment demonstrate the distinct enhancing effect on water-SOM interactions. In contrast, the "low-polarity" organic compounds, e.g., hydrocarbons or their halogen-substituted derivatives, produce a weakening effect on water-SOM interactions

  11. New effective chemically synthesized anti-smallpox compound NIOCH-14.

    PubMed

    Mazurkov, Oleg Yu; Kabanov, Alexey S; Shishkina, Larisa N; Sergeev, Alexander A; Skarnovich, Maksim O; Bormotov, Nikolay I; Skarnovich, Maria A; Ovchinnikova, Alena S; Titova, Ksenya A; Galahova, Darya O; Bulychev, Leonid E; Sergeev, Artemiy A; Taranov, Oleg S; Selivanov, Boris A; Tikhonov, Alexey Ya; Zavjalov, Evgenii L; Agafonov, Alexander P; Sergeev, Alexander N

    2016-05-01

    Antiviral activity of the new chemically synthesized compound NIOCH-14 (a derivative of tricyclodicarboxylic acid) in comparison with ST-246 (the condensed derivative of pyrroledione) was observed in experiments in vitro and in vivo using orthopoxviruses including highly pathogenic ones. After oral administration of NIOCH-14 to outbred ICR mice infected intranasally with 100 % lethal dose of ectromelia virus, it was shown that 50 % effective doses of NIOCH-14 and ST-246 did not significantly differ. The 'therapeutic window' varied from 1 day before infection to 6 days post-infection (p.i.) to achieve 100-60 % survival rate. The administration of NIOCH-14 and ST-246 to mice resulted in a significant reduction of ectromelia virus titres in organs examined as compared with the control and also reduced pathological changes in the lungs 6 days p.i. Oral administration of NIOCH-14 and ST-246 to ICR mice and marmots challenged with monkeypox virus as compared with the control resulted in a significant reduction of virus production in the lungs and the proportion of infected mice 7 days p.i. as well as the absence of disease in marmots. Significantly lower proportions of infected mice and virus production levels in the lungs as compared with the control were demonstrated in experiments after oral administration of NIOCH-14 and ST-246 to ICR mice and immunodeficient SCID mice challenged with variola virus 3 and 4 days p.i., respectively. The results obtained suggest good prospects for further study of the chemical compound NIOCH-14 to create a new smallpox drug on its basis.

  12. New effective chemically synthesized anti-smallpox compound NIOCH-14.

    PubMed

    Mazurkov, Oleg Yu; Kabanov, Alexey S; Shishkina, Larisa N; Sergeev, Alexander A; Skarnovich, Maksim O; Bormotov, Nikolay I; Skarnovich, Maria A; Ovchinnikova, Alena S; Titova, Ksenya A; Galahova, Darya O; Bulychev, Leonid E; Sergeev, Artemiy A; Taranov, Oleg S; Selivanov, Boris A; Tikhonov, Alexey Ya; Zavjalov, Evgenii L; Agafonov, Alexander P; Sergeev, Alexander N

    2016-05-01

    Antiviral activity of the new chemically synthesized compound NIOCH-14 (a derivative of tricyclodicarboxylic acid) in comparison with ST-246 (the condensed derivative of pyrroledione) was observed in experiments in vitro and in vivo using orthopoxviruses including highly pathogenic ones. After oral administration of NIOCH-14 to outbred ICR mice infected intranasally with 100 % lethal dose of ectromelia virus, it was shown that 50 % effective doses of NIOCH-14 and ST-246 did not significantly differ. The 'therapeutic window' varied from 1 day before infection to 6 days post-infection (p.i.) to achieve 100-60 % survival rate. The administration of NIOCH-14 and ST-246 to mice resulted in a significant reduction of ectromelia virus titres in organs examined as compared with the control and also reduced pathological changes in the lungs 6 days p.i. Oral administration of NIOCH-14 and ST-246 to ICR mice and marmots challenged with monkeypox virus as compared with the control resulted in a significant reduction of virus production in the lungs and the proportion of infected mice 7 days p.i. as well as the absence of disease in marmots. Significantly lower proportions of infected mice and virus production levels in the lungs as compared with the control were demonstrated in experiments after oral administration of NIOCH-14 and ST-246 to ICR mice and immunodeficient SCID mice challenged with variola virus 3 and 4 days p.i., respectively. The results obtained suggest good prospects for further study of the chemical compound NIOCH-14 to create a new smallpox drug on its basis. PMID:26861777

  13. Determination of Wastewater Compounds in Sediment and Soil by Pressurized Solvent Extraction, Solid-Phase Extraction, and Capillary-Column Gas Chromatography/Mass Spectrometry

    USGS Publications Warehouse

    Burkhardt, Mark R.; Zaugg, Steven D.; Smith, Steven G.; ReVello, Rhiannon C.

    2006-01-01

    A method for the determination of 61 compounds in environmental sediment and soil samples is described. The method was developed in response to increasing concern over the effects of endocrine-disrupting chemicals in wastewater and wastewater-impacted sediment on aquatic organisms. This method also may be used to evaluate the effects of combined sanitary and storm-sewer overflow on the water and sediment quality of urban streams. Method development focused on the determination of compounds that were chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Sediment and soil samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from interfering matrix components by high-pressure water/isopropyl alcohol extraction. The compounds were isolated using disposable solid-phase extraction (SPE) cartridges containing chemically modified polystyrene-divinylbenzene resin. The cartridges were dried with nitrogen gas, and then sorbed compounds were eluted with methylene chloride (80 percent)-diethyl ether (20 percent) through Florisil/sodium sulfate SPE cartridge, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-sand samples fortified at 4 to 72 micrograms averaged 76 percent ?13 percent relative standard deviation for all method compounds. Initial method reporting levels for single-component compounds ranged from 50 to 500 micrograms per kilogram. The concentrations of 20 out of 61 compounds initially will be reported as estimated with the 'E' remark code for one of three reasons: (1) unacceptably low-biased recovery (less than 60 percent) or highly variable method performance

  14. Position for determining gas-phase volatile organic compound concentrations in transuranic waste containers. Revision 2

    SciTech Connect

    Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R.

    1998-06-01

    In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.

  15. Position for determining gas phase volatile organic compound concentrations in transuranic waste containers. Revision 1

    SciTech Connect

    Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R.

    1995-08-01

    In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering Laboratory (INEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.

  16. A general, cryogenically-based analytical technique for the determination of trace quantities of volatile organic compounds in the atmosphere

    NASA Technical Reports Server (NTRS)

    Coleman, R. A.; Cofer, W. R., III; Edahl, R. A., Jr.

    1985-01-01

    An analytical technique for the determination of trace (sub-ppbv) quantities of volatile organic compounds in air was developed. A liquid nitrogen-cooled trap operated at reduced pressures in series with a Dupont Nafion-based drying tube and a gas chromatograph was utilized. The technique is capable of analyzing a variety of organic compounds, from simple alkanes to alcohols, while offering a high level of precision, peak sharpness, and sensitivity.

  17. Determination of volatile aroma compounds of Ganoderma lucidum by gas chromatography mass spectrometry (HS-GC/MS).

    PubMed

    Taşkın, Hatıra; Kafkas, Ebru; Çakıroğlu, Özgün; Büyükalaca, Saadet

    2013-01-01

    This study was conducted at Horticulture Department of Cukurova University, Adana, Turkey during 2010-2011. Fresh sample of Ganoderma lucidum collected from Mersin province of Turkey was used as material. Volatile aroma compounds were performed by Headspace Gas Chromatography (HS-GC/MS). Alcohols, aldehydes, acids, phenol, L-Alanine, d-Alanine, 3Methyl, 2-Butanamine, 2-Propanamine were determined. 1-Octen-3-ol (Alcohol) and 3-methyl butanal (Aldehyde) were identified as major aroma compounds.

  18. Validation of determination of plasma metabolites derived from thyme bioactive compounds by improved liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rubió, Laura; Serra, Aida; Macià, Alba; Borràs, Xenia; Romero, Maria-Paz; Motilva, Maria-José

    2012-09-15

    In the present study, a selective and sensitive method, based on microelution solid-phase extraction (μSPE) plate and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was validated and applied to determine the plasma metabolites of the bioactive compounds of thyme. For validation process, standards of the more representative components of the phenolic and monoterpene fractions of thyme were spiked in plasma samples and then the quality parameters of the method were studied. Extraction recoveries (%R) of the studied compounds were higher than 75%, and the matrix effect (%ME) was lower than 18%. The LODs ranged from 1 to 65 μg/L, except for the thymol sulfate metabolite, which was 240 μg/L. This method was then applied for the analysis of rat plasma obtained at different times, from 0 to 6h, after an acute intake of thyme extract (5 g/kg body weight). Different thyme metabolites were identified and were mainly derived from rosmarinic acid (coumaric acid sulfate, caffeic acid sulfate, ferulic acid sulfate, hydroxyphenylpropionic acid sulfate, dihydroxyphenylpropionic acid sulfate and hydroxybenzoic acid) and thymol (thymol sulfate and thymol glucuronide). The most abundant thyme metabolites generated were hydroxyphenylpropionic acid sulfate and thymol sulfate, their respective concentrations in plasma being 446 and 8464 μM 1h after the intake of the thyme extract.

  19. Validation of determination of plasma metabolites derived from thyme bioactive compounds by improved liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rubió, Laura; Serra, Aida; Macià, Alba; Borràs, Xenia; Romero, Maria-Paz; Motilva, Maria-José

    2012-09-15

    In the present study, a selective and sensitive method, based on microelution solid-phase extraction (μSPE) plate and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was validated and applied to determine the plasma metabolites of the bioactive compounds of thyme. For validation process, standards of the more representative components of the phenolic and monoterpene fractions of thyme were spiked in plasma samples and then the quality parameters of the method were studied. Extraction recoveries (%R) of the studied compounds were higher than 75%, and the matrix effect (%ME) was lower than 18%. The LODs ranged from 1 to 65 μg/L, except for the thymol sulfate metabolite, which was 240 μg/L. This method was then applied for the analysis of rat plasma obtained at different times, from 0 to 6h, after an acute intake of thyme extract (5 g/kg body weight). Different thyme metabolites were identified and were mainly derived from rosmarinic acid (coumaric acid sulfate, caffeic acid sulfate, ferulic acid sulfate, hydroxyphenylpropionic acid sulfate, dihydroxyphenylpropionic acid sulfate and hydroxybenzoic acid) and thymol (thymol sulfate and thymol glucuronide). The most abundant thyme metabolites generated were hydroxyphenylpropionic acid sulfate and thymol sulfate, their respective concentrations in plasma being 446 and 8464 μM 1h after the intake of the thyme extract. PMID:22939267

  20. Use of solubilizers in preclinical formulations: Effect of Cremophor EL on the pharmacokinetic properties on early discovery compounds.

    PubMed

    Liu, Bo; Gordon, William Perry; Richmond, Wendy; Groessl, Todd; Tuntland, Tove

    2016-05-25

    The aim of the present study was to determine whether Cremophor EL is a suitable surfactant that can be routinely applied to pharmacokinetic (PK) studies in early drug discovery without influencing the intrinsic PK characteristics of the new chemical entities (NCEs). Cremophor EL, a polyoxyl 35 castor oil, has been used as a solubilization aid for water-insoluble compounds in pre-clinical drug discovery. The effect of Cremophor EL on the PK properties of NCEs was examined in seven structurally diverse discovery compounds after intravenous administration. Significant effects of Cremophor EL on plasma volume of distribution (Vss) and plasma clearance (CL) were observed in compounds with moderate to high Vss or CL. The plasma Vss decreased more than 2-fold and the Vss binning category decreased by one unit (e.g. from moderate to low Vss) in 6 of 7 test compounds. Two to five-fold reduction of CL was observed with these 6 compounds. Effect on the terminal half-life (T1/2) was minimal. Using one of these 7 NCEs, concentration dependent effect of Cremophor EL in the vehicle was also determined. Higher percentage of Cremophor EL in vehicle resulted in progressively increased alterations on the plasma CL and Vss. Taken together, these findings indicated that Cremophor EL altered the intrinsic PK properties of these discovery compounds in a concentration dependent manner.

  1. Effect of thiohydroxyl compounds on tyrosinase: inactivation and reactivation study.

    PubMed

    Park, Yong-Doo; Lee, Su-Jin; Park, Kyung-Hee; Kim, So-yeon; Hahn, Myong-Joon; Yang, Jun-Mo

    2003-11-01

    An unusual thioether bridge (Cys-His) has been detected at the active site of mushroom tyrosinase, and the effects of thiohydroxyl compounds such as dithiothreitol (DTT) and beta-mercaptoethanol (beta-ME) on Cu2+ at the active site have been elucidated. Treatment with DTT and beta-ME on mushroom tyrosinase completely inactivated 3,4-dihydroxyphenylalanine oxidase activity in a dose-dependent manner. Sequential kinetic studies revealed that DTT and beta-ME caused different mixed-type inhibition mechanisms: the slope-parabolic competitive inhibition (Ki = 0.143 mM) by DTT and slope-hyperbolic noncompetitive inhibition (Ki = 0.0128 mM) by beta-ME, respectively. Kinetic Scatchard analysis consistently showed that mushroom tyrosinase had multiple binding sites for DTT and beta-ME with different affinities. Reactivation study of inactivated enzyme by addition of Cu2+ confirmed that DTT and beta-ME directly bound with Cu2+ at the active site. Our results may provide useful information regarding interactions of tyrosinase inhibitor for designing an effective whitening agent targeted to the tyrosinase active site. PMID:14714728

  2. Releasing effects in flame photometry: Determination of calcium

    USGS Publications Warehouse

    Dinnin, J.I.

    1960-01-01

    Strontium, lanthanum, neodymium, samarium, and yttrium completely release the flame emission of calcium from the depressive effects of sulfate, phosphate, and aluminate. Magnesium, beryllium, barium, and scandium release most of the calcium emission. These cations, when present in high concentration, preferentially form compounds with the depressing anions when the solution is evaporated rapidly in the flame. The mechanism of the interference and releasing effects is explained on the basis of the chemical equilibria in the evaporating droplets of solution and is shown to depend upon the nature of the compounds present in the aqueous phase of the solution. The need for background correction techniques is stressed. The releasing effect is used in the determination of calcium in silicate rocks without the need for separations.

  3. Cytotoxic Effect of a Novel Synthesized Carbazole Compound on A549 Lung Cancer Cell Line

    PubMed Central

    Molatlhegi, Refilwe P.; Phulukdaree, Alisa; Anand, Krishnan; Gengan, Robert M.; Tiloke, Charlette; Chuturgoon, Anil A.

    2015-01-01

    Increased death rates due to lung cancer have necessitated the search for potential novel anticancer compounds such as carbazole derivatives. Carbazoles are aromatic heterocyclic compounds with anticancer, antibacterial and anti-inflammatory activity. The study investigated the ability of the novel carbazole compound (Z)-4-[9-ethyl-9aH-carbazol-3-yl) amino] pent-3-en-2-one (ECAP) to induce cytotoxicity of lung cancer cells and its mechanism of action. ECAP was synthesized as a yellow powder with melting point of 240-247 °C. The 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), lipid peroxidation and comet assays were used to assess the cytotoxic effect of the compound on A549 lung cancer cells. Protein expression was determined using western blots, apoptosis was measured by luminometry (caspase-3/7, -8 and -9) assay and flow cytometry was used to measure phosphatidylserine (PS) externalisation. ECAP induced a p53 mediated apoptosis of lung cancer cells due to a significant reduction in the expression of antioxidant defence proteins (Nrf2 and SOD), Hsp70 (p < 0.02) and Bcl-2 (p < 0.0006), thereby up-regulating reactive oxygen species (ROS) production. This resulted in DNA damage (p < 0.0001), up-regulation of Bax expression and caspase activity and induction of apoptosis in lung cancer cells. The results show the anticancer potential of ECAP on lung cancer. PMID:26134408

  4. Immunomodulatory effect of selenosemicarbazides and selenium inorganic compounds, distribution in organs after selenium supplementation.

    PubMed

    Musik, I; Koziol-Montewka, M; Toś-Luty, S; Pasternak, K; Latuszyńska, J; Tokarska, M; Kielczykowska, M

    1999-12-01

    Antioxidant properties of selenium producing a protective barrier against free radicals play an important role in numerous metabolic and immunologic processes associated with oxidation-reduction reactions which take place during intracellular digestion of phagocyted bacteria. The aim of our study was to examine the properties of an organic compound of selenium, 4-(o-tolilo)-selenosemicarbazide of p-chlorobenzoic acid in terms of its retention in organs, effect on erythropoesis and phagocytic abilities of neutrophiles as well as antioxidant properties in neutrophiles tested with NBT test. This compound as well as inorganic sodium selenate was given to Swiss mice at the dose of 10(-3) g Se/kg for the period of 10 days. The concentrations of selenium in livers of mice treated with sodium selenate and selenosemicarbazide were found to be higher than in controls (18.7 micrograms lg-1 and 23.2 micrograms lg-1 vs. 12 micrograms lg-1, respectively). Analysis of blood cells count has shown a significant decrease in neutrophile levels in both groups treated with selenium. The influence of selenium compounds on phagocytosis and especially NBT test has been determined (3.8% of positive cells in the controls vs. 2.2% and 0.9% in the groups treated with sodium selenate and selenosemicarbazide, respectively). Our preliminary investigations suggest that selenosemicarbazides are biologically active compounds and can modify neutrophile functions.

  5. Determination of phenolic compounds and antioxidant activity in leaves from wild Rubus L. species.

    PubMed

    Oszmiański, Jan; Wojdyło, Aneta; Nowicka, Paulina; Teleszko, Mirosława; Cebulak, Tomasz; Wolanin, Mateusz

    2015-03-18

    Twenty-six different wild blackberry leaf samples were harvested from various localities throughout southeastern Poland. Leaf samples were assessed regarding their phenolic compound profiles and contents by LC/MS QTOF, and their antioxidant activity by ABTS and FRAP. Thirty-three phenolic compounds were detected (15 flavonols, 13 hydroxycinnamic acids, three ellagic acid derivatives and two flavones). Ellagic acid derivatives were the predominant compounds in the analyzed leaves, especially sanguiin H-6, ellagitannins, lambertianin C, and casuarinin. The content of phenolic compounds was significantly correlated with the antioxidant activity of the analyzed samples. The highest level of phenolic compounds was measured for R. perrobustus, R. wimmerianus, R. pedemontanus and R. grabowskii. The study showed that wild blackberry leaves can be considered a good source of antioxidant compounds. There is clear potential for the utilization of blackberry leaves as a food additive, medicinal source or herbal tea.

  6. Effects of organosilicon compounds, bearing molecular substitutions, on mouse liver glycogen

    SciTech Connect

    Gulley, C.

    1987-01-01

    This study was conducted to observe the effects of organosilicon compounds on the liver glycogen levels of Jax Albino mice. Tris(trimethylisilyl) methylcarboxylic acid, hexaphenyldisilane and tris(trimethylsilyl) bromomethane were fed to mice ad libitum in an organosilicon compound-laboratory chow mixture for 3 one week periods. At the ends of each period, the mice were sacrificed, their livers removed, glycogen was extracted, and subjected to acid hydrolysis. The concentration of free glucose units were determined using the 3,5 dinitrosalicylate reagent. Compared with the controls, tris(trimethylsilyl) methylcarboxylic acid caused a slight depletion of liver glycogen. Hexaphenyldisilane caused a greater depletion of the glycogen stores, and tris(trimethylsilyl) bromomethane caused the greatest depletion of the glycogen stores.

  7. A novel laboratory system for determining fate of volatile organic compounds in planted systems

    SciTech Connect

    Orchard, B.J.; Doucette, W.J.; Chard, J.K; Bugbee, B.

    2000-04-01

    Contradictory observations regarding the uptake and translocation of volatile organic compounds (VOCs) by plants have been reported, most notably for trichloroethylene (TCE). Experimental artifacts resulting from the use of semistatic or low-flow laboratory systems may account for part of the discrepancy. Innovative plant growth chambers are required to rigorously quantify the movement of VOCs through higher plants while maintaining a natural plant environment. The plant must be sealed in a chamber that allows rapid exchange of air to remove the water vapor lost in transpiration, to resupply the CO{sub 2} consumed in photosynthesis, and to resupply the O{sub 2} consumed in root-zone respiration. Inadequate airflow through the foliar region results in high humidity, which dramatically reduces transpiration and may reduce contaminant flux. Oxygen depletion in static root zones induces root stress, which can increase root membrane permeability. The root zone must be separated from the shoots to differentiate between plant uptake and foliar deposition. Here the authors describe the design, construction, and testing of a dual-vacuum, continuous high-flow chamber systems for accurately determining the fate of VOCs plants. The system provides a natural plant environment, complete root/shoot separation, the ability to quantify phytovolatilization and mineralization in both root and shoot compartments, continuous root-zone aeration, and high mass recovery.

  8. Antioxidant activities and determination of phenolic compounds isolated from oriental plums (Soldam, Oishiwase and Formosa)

    PubMed Central

    Kim, Mee-Ree; Cho, Soo-Muk; Kim, So-Young; Kim, Jung-Bong; Cho, Young-Sook

    2012-01-01

    The purposes of this study were to determine phenolic compounds and to evaluate antioxidant activities of plums (Soldam, Oishiwase and Formosa). Soldam contains the highest amount of total phenolics among cultivars (Formosa: 4.0%, Oishiwase: 3.3%, Soldam: 6.4% for total phenolic) as well as the total flavonoids of which constituents were mainly myricetin and anthocyanidin. The antioxidant activities were measured by DPPH, ABTS radical scavenging, and SOD-like activities. The DPPH radical scavenging activity of Korean plum extracts (200 µg/mL) showed more than 43%, and the Soldam turned out to be the highest : ID50 value: 160-177 µg/mL for Formosa and Oishiwase; 58-64 µg/mL for Soldam. The ABTS radical scavenging activity of Korean plum extracts (200 µg/mL) was found to be more than 50%. The SOD-like activity of Korean plum extracts (200 µg/mL) showed more than 70%. Among three kinds of cultivars, Soldam had the highest antioxidant activity. The nitrite scavenging activity of Soldam was 61.5%, which is the highest, compared with that of the other cultivars, about 50%. From these results, Korean plums turned out to be phytochemical rich fruit as well as to show high antioxidant activities. PMID:22977680

  9. Determinants of maternal and fetal exposure and temporal trends of perfluorinated compounds.

    PubMed

    Ode, Amanda; Rylander, Lars; Lindh, Christian H; Källén, Karin; Jönsson, Bo A G; Gustafsson, Peik; Olofsson, Per; Ivarsson, Sten A; Rignell-Hydbom, Anna

    2013-11-01

    In recent years, some perfluorinated compounds (PFCs) have been identified as potentially hazardous substances which are harmful to the environment and human health. According to limited data, PFC levels in humans could be influenced by several determinants. However, the findings are inconsistent. In the present study, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were measured in paired maternal and cord serum samples (N=237) collected between 1978 and 2001 in Southern Sweden to study the relationship between these and to investigate several potential determinants of maternal and fetal exposure to PFCs. Time trends of PFCs in Swedish women were also evaluated. The study is a part of the Fetal Environment and Neurodevelopment Disorders in Epidemiological Research project. PFOS, PFOA, and PFNA levels (median) were higher in maternal serum (15, 2.1, and 0.24 ng/ml, respectively) than in cord serum (6.5, 1.7, and 0.20 ng/ml, respectively). PFC levels were among the highest in women originating from the Nordic countries and the lowest in women from the Middle East, North Africa, and sub-Saharan Africa. Multiparous women had lower serum PFOA levels (1.7 ng/ml) than primiparous women (2.4 ng/ml). Maternal age, body mass index, cotinine levels, and whether women carried male or female fetuses did not affect serum PFC concentrations. Umbilical cord serum PFC concentrations showed roughly similar patterns as the maternal except for the gestational age where PFC levels increased with advancing gestational age. PFOS levels increased during the study period in native Swedish women. In summary, PFOS levels tend to increase while PFOA and PFNA levels were unchanged between 1978 and 2001 in our study population. Our results demonstrate that maternal country of origin, parity, and gestational age might be associated with PFC exposure. PMID:23436123

  10. Position for determining gas phase volatile organic compound concentrations in transuranic waste containers

    SciTech Connect

    Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A. Spangler, L.R.

    1995-12-01

    In the conditional no-migration determination (NMD) for the test phase of the Waste isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. The EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is unnecessary. A test program was conducted to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative.

  11. [Health effect of volatile aldehyde compounds in photocatalytic oxidation of aromatics compounds].

    PubMed

    Zhao, Wei-rong; Liao, Qiu-wen; Yang, Ya-nan; Dai, Jiu-song

    2013-05-01

    Photocatalytic oxidation (PCO) of toluene and benzaldehyde in indoor air by N doped TiO2 (N-TiO2) was conducted under UV irradiation of 254 nm. The intermediates were identified and monitored on real-time by proton transfer reaction-mass spectrometry. The health risks of PCO of toluene and benzaldehyde were assessed based on health risk influence index (eta). Results indicated that both the conversion rate and mineralization rate of toluene and benzaldehyde were relatively high, however, the volatile aldehyde compounds (VAs), including acetaldehyde and formaldehyde generated from ring-opening, significantly influenced the health risks of PCO of toluene and benzaldehyde. Acetaldehyde played a crucial role on health risks, which was inclined to desorb from the surface of catalysts, accumulate in gas-phase, and increase the health risks of PCO of the aromatic compounds. The concentration of formaldehyde kept stable at a relatively low level, however its impact cannot be neglected. In the PCO process of toluene and benzaldehyde, eta reached the maximum values of 8 499.68 and 21.43, with the eta(VAs), contribution of VAs to the health risk influence index of outlet, reaching 99.3% and 98.3%, respectively. The average values of eta in the PCO process of 30 min were 932.86 and 8.52, and for which eta(VAs), reached 98.5% and 98.0%, respectively. When PCO of toluene and benzaldehyde reached steady state, eta were 236.09 and 2.30, and eta(VAs) reached 97.9% and 97.8%, respectively. Hence, eta(VAs), can be taken as a characteristic parameter in assessment of health risks of PCO of aromatic compounds.

  12. Development and validation of RP-HPLC method to determine anti-allergic compound in Thai traditional remedy called Benjalokawichien.

    PubMed

    Sakpakdeejaroen, Intouch; Juckmeta, Thana; Itharat, Arunporn

    2014-08-01

    Benjalokawichien (BLW) or Ya-Ha-Rak (HR) is a traditional remedy in the Nationaldrug list of herbal medicinal products AD 2012 of Thailand. For traditional use, BLW is used as antipyretic agent. It also has anti-allergic effect, particularly treating allergic rash. The ethanolic extract of BLW exhibited anti-allergic activity via inhibitory effect against a release ofbeta-hexosaminidase in RBL-2H3 cell line. Pectolinarigenin has been identified as the active compound ofBLW extract. In this study, a reversed-phase high performance liquid chromatography (RP-HPLC) method was developed in order to control quality ofpreparation in three aspects such as chemical fingerprint, quantification and stability of the ethanolic extract. The RP-HPLC was performed with a gradient mobile phase composed of 0.1% ortho phosphoric acid and acetronitrile, and peaks were detected at 331 nm. Based on validation results, this analytical method is precise, accurate and stable for quantitative determination ofpectolinarigenin. The amount ofpectolinarigenin in Benjalokawichien extract determined by this method was 18.50 mg/g ofextract. Therefore, this method could be consideredfor quality control ofBLWextract. PMID:25518297

  13. Effects of green tea compounds on irinotecan metabolism.

    PubMed

    Mirkov, Snezana; Komoroski, Bernard J; Ramírez, Jacqueline; Graber, Andrea Yoder; Ratain, Mark J; Strom, Stephen C; Innocenti, Federico

    2007-02-01

    The effects of green tea compounds on the metabolism of irinotecan have never been investigated. We aimed to study whether catechins [(-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), (-)-epicatechin] affect the inactivation metabolism of irinotecan into 7-ethyl-10-[4-N-(1-piperidino)-1-amino]carbonyloxycamptothecin (NPC) (by CYP3A4) and 7-ethyl-10-hydroxycamptothecin (SN-38) into 7-ethyl-10-hydroxycamptothecin glucuronide (SN-38G) (by UGT1A1). Human liver microsomes, hepatocytes and Hep G2 cells were incubated with catechins and treated with irinotecan and/or SN-38. NPC and SN-38G formation was measured by high-performance liquid chromatography. UGT1A1 mRNA levels were measured by real-time polymerase chain reaction. In human liver microsomes, a concentration-dependent decrease in the formation of NPC and SN-38G was observed. In human hepatocytes, a significant increase in SN-38G production was observed in 33% (EGCG), 44% (ECG), and 44% (EGC) of the hepatocyte preparations. Phenobarbital increased the formation of SN-38G in 100% of the same hepatocyte preparations. In Hep G2 cells, no increase in SN-38G formation was observed. With the exception of ECG in one liver, catechins did not increase UGT1A1 mRNA levels. NPC production was also significantly increased in 40% of the hepatocyte preparations for each catechin. However, the production of 6beta-hydroxytestosterone remained unaffected in other hepatocyte preparations. At pharmacologically relevant concentrations, catechins are unlikely to inhibit the formation of irinotecan inactive metabolites when administered concomitantly. The induction effect of catechins on UGT1A1 seems to be modest and highly variable. Catechins do not induce CYP3A4 activity. The effect of acute and prolonged use of green tea on the pharmacokinetics of irinotecan in patients remains to be evaluated. PMID:17108060

  14. Rubber (Hevea brasiliensis) seed oil toxicity effect and Linamarin compound analysis

    PubMed Central

    2012-01-01

    Background The lipid fraction of rubber (Hevea brasiliensis (kunth. Muell)) seed was extracted and analyzed for toxicological effect. The toxicological compound such as linamarin in rubber seed oil (RSO) extracted using different solvents, such as hexane (RSOh), mixture of chloroform + methanol (RSOchl+mth) and ethanol (RSOeth) were also studied. Various methods analysis such as Fourier transforms infrared spectroscopy (FTIR) and colorimetric methods were carried out to determine the present of such compounds. Results FTIR spectrum of RSO did not show any presence of cyanide peak. The determination of cyanide by using colorimetric method was demonstrated no response of the cyanide in RSO and didn’t show any colored comparing with commercial cyanide which observed blue color. The results showed that no functional groups such as cyanide (C ≡ N) associated with linamarin were observed. Toxicological test using rats was also conducted to further confirm the absence of such compounds. RSO did not show any toxic potential to the rats. Bioassay experiments using shrimps had been used as test organisms to evaluate the toxicity of linamarin extract from RSOh, RSOchl+mth and RSOeth and LC50 were found to be (211.70 %, 139.40 %, and 117.41 %, respectively). Conclusions This can be attributed no hazardous linamarin were found in RSO. PMID:22694753

  15. Antiproliferative Effect and the Isolated Compounds of Pouzolzia indica

    PubMed Central

    Sangsuwon, Chanyapat; Jiratchariyakul, Weena; U-pratya, Yaowalak; Kummalue, Tanawan

    2013-01-01

    Previous report showed the high potent antiproliferative effect of the methanolic part extracted from the aerial parts of Pouzolzia indica on NB4 and HT93A acute leukemic cell lines with the IC50 values of 28.5 and 49.8 μg/mL, respectively. The bioassay-guided fractionation of the methanolic part gave 5 fractions, that is, FFI–FFV. FFII, FFIII, and FFIV inhibited the above leukemic cell lines with the IC50 values of 15.1 (FFII), 14.4 (FFIII), 32.1 (FFIV), and 31.0 (FFII), 9.7 (FFIII), 10.5 (FFIV) μg/mL, respectively. The compounds in these fractions were isolated using chromatographic technique. FFII contained friedelin 1, 28-hydroxy-3-friedelanone 2, and 7-methoxy-coumarin 3. FFIII contained 6, 7-dimethoxy-coumarin 4, scopoletin 5, methyl caffeate 6. FFIV contained sitosteryl glucoside 7 and a supposed glycosphingolipid 8. The chemical structures were elucidated by spectroscopic methods. PMID:23762121

  16. Psychological effects of musky compounds: comparison of androstadienone with androstenol and muscone.

    PubMed

    Jacob, Suma; Garcia, Sheila; Hayreh, Davinder; McClintock, Martha K

    2002-11-01

    Previously, we have shown that delta4,16-androstadien-3-one modulates psychological state, reducing negative mood and increasing positive mood (Jacob and McClintock, 2000; Jacob et al., 2001a). In order to determine whether similar musky compounds also produce these effects, we compared the effects of androstadienone to those of androstenol and muscone, measuring the psychological states of 37 participants. Androstenol and muscone were chosen because they too have a musky odor at high concentrations, while androstenol is a steroid like androstadienone and muscone is not. In a controlled laboratory setting, we conducted a double-blind, within-subject, repeated-measures experiment counterbalanced for order of presentation. Under each participant's nose, a nanomolar amount of each compound was presented, masked by clove oil to minimize perceptible olfactory differences. Participants completed a baseline psychological battery and twice again at 25-min intervals after exposure. Androstadienone's effects on psychological state were unique in comparison with those of androstenol and with muscone. Exposure through passive inhalation, rather than dermal contact, was sufficient for these effects. Although this is additional evidence that androstadienone may be a pheromone, it is yet to be determined whether humans exude concentrations into the air adequate for social communication or process this chemical information within natural social contexts.

  17. Psychological effects of musky compounds: comparison of androstadienone with androstenol and muscone.

    PubMed

    Jacob, Suma; Garcia, Sheila; Hayreh, Davinder; McClintock, Martha K

    2002-11-01

    Previously, we have shown that delta4,16-androstadien-3-one modulates psychological state, reducing negative mood and increasing positive mood (Jacob and McClintock, 2000; Jacob et al., 2001a). In order to determine whether similar musky compounds also produce these effects, we compared the effects of androstadienone to those of androstenol and muscone, measuring the psychological states of 37 participants. Androstenol and muscone were chosen because they too have a musky odor at high concentrations, while androstenol is a steroid like androstadienone and muscone is not. In a controlled laboratory setting, we conducted a double-blind, within-subject, repeated-measures experiment counterbalanced for order of presentation. Under each participant's nose, a nanomolar amount of each compound was presented, masked by clove oil to minimize perceptible olfactory differences. Participants completed a baseline psychological battery and twice again at 25-min intervals after exposure. Androstadienone's effects on psychological state were unique in comparison with those of androstenol and with muscone. Exposure through passive inhalation, rather than dermal contact, was sufficient for these effects. Although this is additional evidence that androstadienone may be a pheromone, it is yet to be determined whether humans exude concentrations into the air adequate for social communication or process this chemical information within natural social contexts. PMID:12460587

  18. Determination of polyphenolic compounds in Cirsium palustre (L.) extracts by high performance liquid chromatography with chemiluminescence detection.

    PubMed

    Nalewajko-Sieliwoniuk, Edyta; Malejko, Julita; Mozolewska, Monika; Wołyniec, Elżbieta; Nazaruk, Jolanta

    2015-02-01

    The first method for the simultaneous determination of polyphenolic antioxidants in extracts from leaves of Cirsium palustre based on high performance liquid chromatography combined with flow injection chemiluminescence detection (HPLC-FI-CL) has been developed. The extracts were prepared by using methanol as extraction medium and two types of extraction methods (reflux and ultrasound assisted extraction). The post-column CL determination of polyphenols was based on their enhancing effect on the chemiluminescence intensity generated in manganese(IV)-hexametaphosphate-formaldehyde system in a phosphoric acid medium. Main antioxidants determined in C. palustre leaves were eriodictyol-7-O-glucoside, luteolin-7-O-glucoside and 6-hydroxyluteolin-7-O-glucoside belonging to flavonoids, and chlorogenic acid belonging to phenolic acids. Chromatographic separation was carried out on a C18 column with gradient elution by using a mobile phase containing 0.25% (v/v) phosphoric acid in water (solvent A) and 100% methanol (solvent B). Under the optimized conditions of chromatographic separation and CL detection the validation of the method was performed. The calibration curves showed good linearity in the concentration range from 0.5 to 40 µg mL(-1). The HPLC-FI-CL method was successfully applied to the determination of four polyphenolic compounds in methanolic extracts from leaves of C. palustre. The accuracy of the developed method was confirmed by the comparison of the results with those obtained by an HPLC-PDA method. The relative error of determination does not exceed 6.1%. However, the HPLC-FI-CL method is characterized by 40-65 times higher sensitivity compared to the HPLC-PDA method.

  19. Determination the total neutron yields of several semiconductor compounds using various alpha emitters

    NASA Astrophysics Data System (ADS)

    Abdullah, Ramadhan Hayder; Sabr, Barzan Nehmat

    2016-03-01

    In the present work, the cross-sections of (α,n) reactions available in the literature as a function of α-particle energies for light and medium elements have been rearranged for α-particle energies from near threshold up to 10 MeV in steps of (0.050MeV) using the (Excel and Matlab) computer programs. The obtained data were used to calculate the neutron yields (n/106α) using the quick basic-computer program (Simpson Rules). The stopping powers of alpha particle energies from near threshold to 10 MeV for light and medium elements such as (nat.Be,10B,11B,13C,14N,nat.O,nat.F,nat.Mg,nat.Al,29Si,30Si, nat.P and 46.48Ti) have been calculated using the Zeigler formula. The kinetic energies (Tα) and the branching ratios of each α-emitters such as (211Bi, 210Po, 211Po, 215Po, 217At, 218Rn, 219Rn, 222Rn, 224Ra, 226Ra, 215Th, 228Th, 232U, 234U, 236U, 238U, 238Pu, 239Pu, 241Am, 245Es, 252Fm, 254Fm, 256Fm, 257Fm and 257Md) are taken into consideration to calculate the mean kinetic energy . The polynomial expressions were used to fitting the calculated weighted average of neutron yields (n/106α) for natural light and medium elements such as (Be, B, C, N, O, F, Mg, Al, Si, P and Ti) to determine the adopted neutron yields from the best fitting equation with minimum (CHISQ) at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gx/ppmi) of the mentioned natural light and medium elements have been calculated using the adopted neutron yields (n/106α) from the fitting equations at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gα-emitters/gcompounds) of semiconductor compounds such as (AlN, AlP, BN, BP, SiC, TiO2, BeSiN2, MgCN2, MgSiN2 and MgSiP2) have been calculated by mixing (1gram) of compounds with (1gram) of pure α-emitters using the quick basic computer program. The aim of the present work is to constructed and fabricate the neutron sources theoretically

  20. A liquid chromatography-atmospheric pressure photoionization tandem mass spectrometric method for the determination of organosulfur compounds in petroleum asphalt cements.

    PubMed

    da Silveira, Géssica Domingos; Faccin, Henrique; Claussen, Luis; Goularte, Rayane Bueno; Do Nascimento, Paulo C; Bohrer, Denise; Cravo, Margareth; Leite, Leni F M; de Carvalho, Leandro Machado

    2016-07-29

    We present a sensitive liquid chromatography-atmospheric pressure photoionization tandem mass spectrometric (UHPLC-APPI-MS/MS) method for the determination of selected organosulfur compounds in Brazilian asphalt cements. It was possible to detect 14 organosulfur compounds of different classes where sulfoxides and sulfones presented higher sensibility in ionization than thiophenes and aromatic sulfides. A dopant-assisted APPI method was also tested, however, when chromatographic flow rate was optimized a decrease in signal was observed for all compounds. PAHs were tested and ruled out as possible interfering compounds and the matrix effect of asphalt cements was within an acceptable range for the quantification of organosulfur compounds. The proposed method was found to have satisfactory linearity and accuracy with recoveries between 83.85 and 110.28% for thianaphthene and 3-methylbenzothiophene, respectively. Therefore, the method allowed the characterization of organosulfur compounds in Brazilian asphalt cements and demonstrated changes in the amount quantified in asphaltenic and maltenic fractions after the RTFOT+SUNTEST aging process. PMID:27342135

  1. Beneficial Effects of Marine Algal Compounds in Cosmeceuticals

    PubMed Central

    Thomas, Noel Vinay; Kim, Se-Kwon

    2013-01-01

    The name “cosmeceuticals” is derived from “cosmetics and pharmaceuticals”, indicating that a specific product contains active ingredients. Marine algae have gained much importance in cosmeceutical product development due to their rich bioactive compounds. In the present review, marine algal compounds (phlorotannins, sulfated polysaccharides and tyrosinase inhibitors) have been discussed toward cosmeceutical application. In addition, atopic dermatitis and the possible role of matrix metalloproteinase (MMP) in skin-related diseases have been explored extensively for cosmeceutical products. The proper development of marine algae compounds will be helpful in cosmeceutical product development and in the development of the cosmeceutical industry. PMID:23344156

  2. DETERMINATION OF POLAR VOLATILE ORGANIC COMPOUNDS IN WATER BY MEMBRANE PERMEATE AND TRAP GC-MS

    EPA Science Inventory

    A novel approach is presented combining semipermeable membranes with the accepted purge and trap gas chromatography-mass spectrometry (GC-MS) technology to produce a method of selectively extracting polar, volatile organic compounds from water, particularly those compounds not am...

  3. Comparison of methods for determining volatile compounds in milk, cheese, and whey powder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but conditions have to be adjusted for optimal SPME release while not generating new compounds that are abs...

  4. Extraction, chemical characterization and biological activity determination of broccoli health promoting compounds.

    PubMed

    Ares, Ana M; Nozal, María J; Bernal, José

    2013-10-25

    Broccoli (Brassica oleracea L. var. Italica) contains substantial amount of health-promoting compounds such as vitamins, glucosinolates, phenolic compounds, and dietary essential minerals; thus, it benefits health beyond providing just basic nutrition, and consumption of broccoli has been increasing over the years. This review gives an overview on the extraction and separation techniques, as well as the biological activity of some of the above mentioned compounds which have been published in the period January 2008 to January 2013. The work has been distributed according to the different families of health promoting compounds discussing the extraction procedures and the analytical techniques employed for their characterization. Finally, information about the different biological activities of these compounds has been also provided.

  5. RP-HPTLC densitometric determination and validation of vanillin and related phenolic compounds in accelerated solvent extract of Vanilla planifolia*.

    PubMed

    Sharma, Upendra Kumar; Sharma, Nandini; Gupta, Ajai Prakash; Kumar, Vinod; Sinha, Arun Kumar

    2007-12-01

    A simple, fast and sensitive RP-HPTLC method is developed for simultaneous quantitative determination of vanillin and related phenolic compounds in ethanolic extracts of Vanilla planifolia pods. In addition to this, the applicability of accelerated solvent extraction (ASE) as an alternative to microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and Soxhlet extraction was also explored for the rapid extraction of phenolic compounds in vanilla pods. Good separation was achieved on aluminium plates precoated with silica gel RP-18 F(254S) in the mobile phase of methanol/water/isopropanol/acetic acid (30:65:2:3, by volume). The method showed good linearity, high precision and good recovery of compounds of interest. ASE showed good extraction efficiency in less time as compared to other techniques for all the phenolic compounds. The present method would be useful for analytical research and for routine analysis of vanilla extracts for their quality control.

  6. Effect of water saturation in soil organic matter on the partition of organic compounds

    USGS Publications Warehouse

    Rutherford, D.W.; Chlou, G.T.

    1992-01-01

    The sorption of benzene, trichloroethylene, and carbon tetrachloride at room temperature from water solution and from vapor on two high-organic-content soils (peat and muck) was determined in order to evaluate the effect of water saturation on the solute partition in soil organic matter (SOM). The uptake of water vapor was similarly determined to define the amounts of water in the saturated soil samples. In such high-organic-content soils the organic vapor sorption and the respective solute sorption from water exhibit linear isotherms over a wide range of relative concentrations. This observation, along with the low BET surface areas of the samples, suggests that partition in the SOM of the samples is the dominant process in the uptake of these liquids. A comparison of the sorption from water solution and from vapor phase shows that water saturation reduces the sorption (partition) efficiency of SOM by ?? 42%; the saturated water content is ??38% by weight of dry SOM. This reduction is relatively small when compared with the almost complete suppression by water of organic compound adsorption on soil minerals. While the effect of water saturation on solute uptake by SOM is much expected in terms of solute partition in SOM, the influence of water on the solubility behavior of polar SOM can be explained only qualitatively by regular solution theory. The results suggest that the major effect of water in a drying-wetting cycle on the organic compound uptake by normal low-organic-content soils (and the associated compound's activity) is the suppression of adsorption by minerals rather than the mitigation of the partition effect in SOM.

  7. The effect of treatment stages on the coking wastewater hazardous compounds and their toxicity.

    PubMed

    Wei, Xiao-xue; Zhang, Zi-yang; Fan, Qing-lan; Yuan, Xiao-ying; Guo, Dong-sheng

    2012-11-15

    This study investigated the change of hazardous materials in coking wastewater at different treatment stages (anaerobic, anaerobic/aerobic, anaerobic/aerobic/photo degradation, anaerobic/aerobic/ozone oxidation treatment) and the effects of them on the development of maize embryos and the activity of amylase and protease in maize seeds. Moreover the interaction of refractory organic matters in the wastewater at different treatment stages with amylase and protease also were determined in vitro. The results show that the biodegradable and the refractory organic compounds in the wastewater both can affect maize embryo development (germination inhibition rate is 19.3% for biodegradable organic compounds). As the treatment stage preceding, the inhibition effect of coking wastewater on the development of the maize embryo (for germination inhibition rates change from 49.3% to 24.6%) and on enzymatic activity (inhibition rates change from 63.9% to 22.4% for amylase) decreases gradually, but the photo-degradation treatment to anaerobic/aerobic effluent can increase its toxicity. The changes in the ability of the refractory organic compounds to bind with enzyme proteins, combined with the analysis of the organic components by GC/MS, show that in the process of coking wastewater treatment no new toxic chemicals were produced. PMID:23022415

  8. Effect of polyphenolic compounds on the growth and cellulolytic activity of a strain of Trichoderma viride

    SciTech Connect

    Arrieta-Escobar, A.; Belin, J.M.

    1982-04-01

    Polyphenolic compounds are often regarded as inhibitors of microorganism growth. However, polyphenolic compounds can also induce stimulating effects on the growth, respiration, fermentation and excretion of amino acids. Depending on the concentration of polyphenolic compounds in the medium, opposed effects (inhibition, stimulation) can be observed. The purpose of this article is to study the effects of condensed tannins and some monomers on the growth and cellulolytic activity of Trichoderma viride. (Refs. 30).

  9. Bioactive Compound Content and Cytotoxic Effect on Human Cancer Cells of Fresh and Processed Yellow Tomatoes.

    PubMed

    Raiola, Assunta; Del Giudice, Rita; Monti, Daria Maria; Tenore, Gian Carlo; Barone, Amalia; Rigano, Maria Manuela

    2015-01-01

    Tomato, as a fresh or processed product, has a high nutritional value due to its content of bioactive components such as phenolic compounds. Few studies describe the effect of processing on antioxidant content and the cancer cell growth inhibition activity. In this study we determined the phenolic and ascorbic acid content of three yellow tomato varieties, before and after thermal processing. Moreover, we determined the antioxidative power and tested the effects of tomato extracts on three human cancer cell lines. We found that the amount of phenolic acids (chlorogenic acid and caffeic acid) decreased in all the samples after processing, whereas the flavonoid content increased after the heat treatment in two samples. A cytotoxic effect of tomato extracts was observed only after processing. This result well correlates with the flavonoid content after processing and clearly indicates that processed yellow tomatoes have a high content of bioactive compounds endowed with cytotoxicity towards cancer cells, thus opening the way to obtain tomato-based functional foods. PMID:26712729

  10. Determination of perfluorinated compounds (PFCs) in various foodstuff packaging materials used in the Greek market.

    PubMed

    Zafeiraki, Effrosyni; Costopoulou, Danae; Vassiliadou, Irene; Bakeas, Evangelos; Leondiadis, Leondios

    2014-01-01

    Perfluorinated compounds (PFCs) are used in food packaging materials as coatings/additives for oil and moisture resistance. In the current study, foodstuff-packaging materials collected from the Greek market, made of paper, paperboard or aluminum foil were analyzed for the determination of PFCs. For the analysis of the samples, pressurized liquid extraction (PLE), liquid chromatography–tandem mass spectrometry (LC–MS/MS) and isotope dilution method were applied to develop a specific and sensitive method of analysis for the quantification of 12 PFCs: perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoA), perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonate (PFOS) and the qualitative detection of 5 more: perfluorotridecanoic acid (PFTrDA), perfluorotetradecanoic acid (PFTeDA), perflyohexadecanoic acid (PFHxDA), perfluorooctadecanoic acid (PFODA) and perfluorodecane sulfonate (PFDS). No PFCs were quantified in aluminum foil wrappers, baking paper materials or beverage cups. PFTrDA, PFTeDA and PFHxDA were detected in fast food boxes. In the ice cream cup sample only PFHxA was found. On the other hand, several PFCs were quantified and detected in fast food wrappers, while the highest levels of PFCs were found in the microwave popcorn bag. PFOA and PFOS were not detected in any of the samples. Compared to other studies from different countries, very low concentrations of PFCs were detected in the packaging materials analyzed. Our results suggest that probably no serious danger for consumers’ health can be associated with PFCs contamination of packaging materials used in Greece. PMID:24367824

  11. Quantitative determination of volatile organic compounds (VOC) in milk by multiple dynamic headspace extraction and GC-MS.

    PubMed

    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.

  12. Determination of volatile compounds in Grenache wines in relation with different terroirs in the Rhone Valley.

    PubMed

    Sabon, Isabelle; De Revel, Gilles; Kotseridis, Yorgos; Bertrand, Alain

    2002-10-23

    This paper describes the study of 19 wines of the Grenache Noir cultivar obtained from representative soils of the Rhone Valley according to their geographical site, climatic conditions, hydrological regulation, and soil profile. Among the volatile compounds analyzed by GC/MS/FID, the concentrations of the varietal compounds (i.e., beta-damascenone, beta-ionone, and geraniol) and those of the compounds without direct influence on the wine aroma (i.e., hexenols and methanol) indicated the existence of two groups of wines. These concentrations were correlated with grape maturity due to the ecosystem and particularly the soil.

  13. Deuterated analogues as internal reference compounds for the direct determination of benzo(a)pyrene and perylene in liquid fuels by laser-excited Shpol'skii spectrometry

    SciTech Connect

    Yen Yang

    1981-11-01

    The polycyclic aromatic hydrocarbon (PAH) content of coal liquefaction products and other liquid fuels is usually assessed by measuring the benzo(a)pyrene content. In Shpol'skii effect spectrometry, PAHs and their deuterated analogues exhibit adequately resolved characteristic quasi-line spectra. The authors have used deuterated benzo(a)pyrene and perylene as externally added internal reference compounds to facilitate the direct determination of benzo(a)pyrene and perylene in liquid fuels.

  14. Protective effect of compound K on diabetic rats.

    PubMed

    Shao, Xiaotong; Li, Na; Zhan, Jinzhuo; Sun, Hui; An, Liping; Du, Peige

    2015-02-01

    Purpose: Compound K (CK), the metabolic product of protopanaxadiol saponin in vivo, has many pharmacological activities. In this study, we discuss the preparation of CK, and its protective effect on kidneys of diabetic rats. CK was prepared from ginsenoside Rbt after transformation by 3-glucosidase, separation and purification by silica gel column chromatography. In the present study, we established a rat model of diabetes mellitus using high-fat diet and streptozotocin (STZ). After seven weeks of treatment, the levels of fasting blood glucose (FBG), total cholesterol (TC), total glycerin (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), blood urea nitrogen (BUN), uric acid (UA), serum creatinine (Scr), malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-PX) were evaluated in normal and diabetic rats. Also, renal pathomorphism changes were observed by HE stain, and TGF-β1 protein expression in the renal tissue was measured by Western blot. The yield of CK was 14.55 mg/mL, which was higher than that of other methods. After seven weeks, CK could decrease FBG, TC, TG, LDL-C, BUN, UA, Scr and MDA of diabetic rats, while CK also enhanced HDL-C and GSH, SOD and GSH-PX. Additionally, CK improved the pathological changes and decreased TGF-β1 protein expression in the renal tissue. CK improved the pathological changes in the renal tissue, enhanced the antioxidant capacity, reduced the damage of TGF-β1 to renal tissue, and protected the diabetic rats.

  15. Determination of Ten Perfluorinated Compounds in Bluegill Sunfish (Lepomis macrochirus) Fillets

    EPA Science Inventory

    Limited information is known about the environmental distributions of the perfluorinated compounds (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), in part due to a lack of well characterized analytical methods that can be used to accurately mea...

  16. Antioxidant and Anti-Inflammatory Activity Determination of One Hundred Kinds of Pure Chemical Compounds Using Offline and Online Screening HPLC Assay

    PubMed Central

    Lee, Kwang Jin; Oh, You Chang; Cho, Won Kyung; Ma, Jin Yeul

    2015-01-01

    This study investigated the antioxidant activity of one hundred kinds of pure chemical compounds found within a number of natural substances and oriental medicinal herbs (OMH). Three different methods were used to evaluate the antioxidant activity of DPPH radical-scavenging activity, ABTS radical-scavenging activity, and online screening HPLC-ABTS assays. The results indicated that 17 compounds exhibited better inhibitory activity against ABTS radical than DPPH radical. The IC50 rate of a more practical substance is determined, and the ABTS assay IC50 values of gallic acid hydrate, (+)-catechin hydrate, caffeic acid, rutin hydrate, hyperoside, quercetin, and kaempferol compounds were 1.03 ± 0.25, 3.12 ± 0.51, 1.59 ± 0.06, 4.68 ± 1.24, 3.54 ± 0.39, 1.89 ± 0.33, and 3.70 ± 0.15 μg/mL, respectively. The ABTS assay is more sensitive to identifying the antioxidant activity since it has faster reaction kinetics and a heightened response to antioxidants. In addition, there was a very small margin of error between the results of the offline-ABTS assay and those of the online screening HPLC-ABTS assay. We also evaluated the effects of 17 compounds on the NO secretion in LPS-stimulated RAW 264.7 cells and also investigated the cytotoxicity of 17 compounds using a cell counting kit (CCK) in order to determine the optimal concentration that would provide an effective anti-inflammatory action with minimum toxicity. These results will be compiled into a database, and this method can be a powerful preselection tool for compounds intended to be studied for their potential bioactivity and antioxidant activity related to their radical-scavenging capacity. PMID:26504472

  17. The experimental determination of the moments of inertia of airplanes by a simplified compound-pendulum method

    NASA Technical Reports Server (NTRS)

    Gracey, William

    1948-01-01

    A simplified compound-pendulum method for the experimental determination of the moments of inertia of airplanes about the x and y axes is described. The method is developed as a modification of the standard pendulum method reported previously in NACA report, NACA-467. A brief review of the older method is included to form a basis for discussion of the simplified method. (author)

  18. CAPILLARY GAS CHROMATOGRAPHY-ATOMIC EMISSION DETECTION METHOD FOR THE DETERMINATION OF PENTYLATED ORGANOTIN COMPOUNDS: INTERLABORATORY STUDY

    EPA Science Inventory

    A capillary gas chromatography-atomic emission detection (GC-AED) method was developed for the U. S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory in Las Vegas, NV, for determination of selected organotin compounds. Here we report on an interlabora...

  19. EFFECT OF TEMPERATURE ON THE C ISOTOPIC VALUE OF MICROBIAL LIPIDS APPLIED TO DETERMINE C USAGE IN MICROBIAL COMMUNITIES

    EPA Science Inventory

    The combination of compound specific stable isotopic analysis with phospholipid fatty acid (PLFAS) analysis is useful in determining the source of organic carbon used by groups of a microbial community. Determination of the effect of certain environmental parameters is important ...

  20. Determination of heat purgeable and ambient purgeable volatile organic compounds in water by gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Rose, Donna L.; Sandstrom, Mark W.; Murtagh, Lucinda K.

    2016-09-08

    Two new analytical methods have been developed by the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) that allow the determination of 37 heat purgeable volatile organic compounds (VOCs) (USGS Method O-4437-16 [NWQL Laboratory Schedule (LS) 4437]) and 49 ambient purgeable VOCs (USGS Method O-4436-16 [NWQL LS 4436]) in unfiltered water. This report documents the procedures and initial performance of both methods. The compounds chosen for inclusion in the methods were determined as having high priority by the USGS National Water-Quality Assessment (NAWQA) Program. Both methods use a purge-and-trap technique with gas chromatography/mass spectrometry. The compounds are extracted from the sample by bubbling helium through a 25-milliliter sample. For the polar and less volatile compounds, the sample is heated at 60 degrees Celsius, whereas the less polar and more volatile compounds are purged using a separate analytical procedure at ambient temperature. The compounds are trapped on a sorbent trap, desorbed into a gas chromatograph/mass spectrometer for separation, and then identified and quantified. Sample preservation is recommended for both methods by adding a 1:1 solution of hydrochloric acid (HCl [1:1]) to water samples to adjust the pH to 2. Analysis within 14 days from sampling is recommended.The heat purgeable method (USGS Method O-4437-16) operates with the mass spectrometer in the simultaneous full scan/selected ion monitoring mode. This method supersedes USGS Method O-4024-03 (NWQL LS 4024). Method detection limits (MDLs) for fumigant compounds 1,2-dibromoethane, 1,2-dichloropropane, 1,2,3-trichloropropane, chloropicrin, and 1,2-dibromo-3-chloropropane range from 0.002 to 0.010 microgram per liter (µg/L). The MDLs for all remaining heat purgeable VOCs range from 0.006 µg/L for tert-butyl methyl ether to 3 µg/L for alpha-terpineol. Calculated holding times indicate that 36 of the 37 heat purgeable VOCs are stable for a minimum of 14 days

  1. Determination of heat purgeable and ambient purgeable volatile organic compounds in water by gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Rose, Donna L.; Sandstrom, Mark W.; Murtagh, Lucinda K.

    2016-01-01

    Two new analytical methods have been developed by the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) that allow the determination of 37 heat purgeable volatile organic compounds (VOCs) (USGS Method O-4437-16 [NWQL Laboratory Schedule (LS) 4437]) and 49 ambient purgeable VOCs (USGS Method O-4436-16 [NWQL LS 4436]) in unfiltered water. This report documents the procedures and initial performance of both methods. The compounds chosen for inclusion in the methods were determined as having high priority by the USGS National Water-Quality Assessment (NAWQA) Program. Both methods use a purge-and-trap technique with gas chromatography/mass spectrometry. The compounds are extracted from the sample by bubbling helium through a 25-milliliter sample. For the polar and less volatile compounds, the sample is heated at 60 degrees Celsius, whereas the less polar and more volatile compounds are purged using a separate analytical procedure at ambient temperature. The compounds are trapped on a sorbent trap, desorbed into a gas chromatograph/mass spectrometer for separation, and then identified and quantified. Sample preservation is recommended for both methods by adding a 1:1 solution of hydrochloric acid (HCl [1:1]) to water samples to adjust the pH to 2. Analysis within 14 days from sampling is recommended.The heat purgeable method (USGS Method O-4437-16) operates with the mass spectrometer in the simultaneous full scan/selected ion monitoring mode. This method supersedes USGS Method O-4024-03 (NWQL LS 4024). Method detection limits (MDLs) for fumigant compounds 1,2-dibromoethane, 1,2-dichloropropane, 1,2,3-trichloropropane, chloropicrin, and 1,2-dibromo-3-chloropropane range from 0.002 to 0.010 microgram per liter (µg/L). The MDLs for all remaining heat purgeable VOCs range from 0.006 µg/L for tert-butyl methyl ether to 3 µg/L for alpha-terpineol. Calculated holding times indicate that 36 of the 37 heat purgeable VOCs are stable for a minimum of 14 days

  2. Efficient and effective compound management to support lead optimization.

    PubMed

    Johnson, Chad W; Chatterjee, Moneesh; Kubala, Steve; Helm, David; Houston, John; Banks, Martyn

    2009-06-01

    The introduction of lean thinking and Six Sigma methodologies into the drug discovery process has become an important approach for ensuring efficient workflows while containing costs. For the compound management department at Bristol-Myers Squibb, this has resulted in a partnership with the research community to evaluate and streamline processes to enable cost-disciplined science. The authors describe the results of Lean Six Sigma approaches in the automation and informatics environment that have been optimized to support parallel processing of compounds. This new platform facilitates the rapid and simultaneous data generation from structure activity and structure liability assays. As a result of these compound management improvements, reduction of timelines and quicker decision making has been achieved in the lead optimization process.

  3. Indirect fluorescent determination of selected nitro-aromatic and pharmaceutical compounds via UV-photolysis of 2-phenylbenzimidazole-5-sulfonate.

    PubMed

    Zhang, Wei; Wilson, Christopher R; Danielson, Neil D

    2008-02-15

    An indirect fluorescence (FL) detection method via the reactivity of UV-photolyzed 2-phenylbenzimidazole-5-sulfonate (PBSA) has been developed for non-fluorescent aromatic compounds. At high pH with UV photolysis, PBSA in the excited state is known to be quenched by reaction with oxygen species and analyte compounds that are reactive toward these oxygen species produced during photolysis can lessen the loss of PBSA FL. After off-line photolysis of PBSA in the presence of various nitro-aromatic test compounds, the increase in PBSA FL is clearly evident. A flow injection (FI) instrument using a PBSA mobile phase propelled through a Teflon coil wrapped around a Hg lamp is optimized and modified for use for liquid chromatography (LC). For the on-line FI determination of the non-fluorescent nitro-aromatic compounds such as 4-nitroaniline, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, and alpha-nitronaphthalene, a positive linear response for PBSA FL from about 0.5 to 15 microM and detection limits generally between 0.2 and 1 microM (4-20 pmol) are found. Linear responses and detection limits of selected pharmaceutical compounds such as the antibacterial nitrofurantoin, antihistamines chlorpheniramine and brompheniramine, and other compounds were similar. In general, detection limits using UV detection at about 214 nm were not as good in the 1-2 microM range but linearity extended up to 100 microM. The amino acid phenylalanine and small peptides containing this aromatic amino acid were also determined using this method. Application of this detection method for the liquid chromatography determination of 4-nitroaniline, 2-nitrophenol, nitrofurantoin, and salicylate is shown.

  4. The effects of plant growth regulators and L-phenylalanine on phenolic compounds of sweet basil.

    PubMed

    Koca, Nülüfer; Karaman, Şengül

    2015-01-01

    The effects of methyl jasmonate (MeJA), spermine (Spm), epibrassinolide (EBL) and l-phenylalanine on sweet basil (Ocimum basilicum L.) were studied to determine the amount of phenolic compounds and enzymatic activity of phenylalanine ammonia-lyase (PAL). Total phenolic and total flavonoid contents of sweet basils were determined by a spectrophotometer, and individual phenolic compounds and activity of PAL were analysed by HPLC/UV. The highest total phenolic (6.72 mg GAE/g) and total flavonoid contents (0.92 mg QE/g) obtained from 1.0 mM Spm+MeJA application. Rosmarinic acid (RA) and caffeic acid contents significantly enhanced after the applications but no such differences observed in chicoric acid content or PAL activity. RA was the main phenolic acid in all samples and its concentration varied from 1.04 to 2.70 mg/gFW. As a result the combinations of Spm+MeJA and EBL+MeJA can induce secondary metabolites effectively and those interactions play important role in the production of phytochemicals in plants.

  5. The effects of plant growth regulators and L-phenylalanine on phenolic compounds of sweet basil.

    PubMed

    Koca, Nülüfer; Karaman, Şengül

    2015-01-01

    The effects of methyl jasmonate (MeJA), spermine (Spm), epibrassinolide (EBL) and l-phenylalanine on sweet basil (Ocimum basilicum L.) were studied to determine the amount of phenolic compounds and enzymatic activity of phenylalanine ammonia-lyase (PAL). Total phenolic and total flavonoid contents of sweet basils were determined by a spectrophotometer, and individual phenolic compounds and activity of PAL were analysed by HPLC/UV. The highest total phenolic (6.72 mg GAE/g) and total flavonoid contents (0.92 mg QE/g) obtained from 1.0 mM Spm+MeJA application. Rosmarinic acid (RA) and caffeic acid contents significantly enhanced after the applications but no such differences observed in chicoric acid content or PAL activity. RA was the main phenolic acid in all samples and its concentration varied from 1.04 to 2.70 mg/gFW. As a result the combinations of Spm+MeJA and EBL+MeJA can induce secondary metabolites effectively and those interactions play important role in the production of phytochemicals in plants. PMID:25053088

  6. Effect of bedding materials on concentration of odorous compounds and in beef cattle bedded manure packs.

    PubMed

    Spiehs, Mindy J; Brown-Brandl, Tami M; Parker, David B; Miller, Daniel N; Berry, Elaine D; Wells, James E

    2013-01-01

    The objectives of this study were to determine the effect of bedding material (corn stover, soybean stover, wheat straw, switchgrass, wood chips, wood shavings, corn cobs, and shredded paper) on concentration of odorous volatile organic compounds (VOC) in bedded pack material and to determine the effect of bedding material on the levels of total in laboratory-scaled bedded manure packs. Four bedded packs of each bedding material were maintained for two 6-wk periods ( = 64). Straight- and branched-chained fatty acids and aromatic compounds were measured. Corn cob bedding had the highest concentration of odorous VOC, and wood shavings had the lowest ( < 0.01). Calculated odor activity values were highest for corn cob bedding and shredded paper and lowest for wood shavings ( < 0.01). concentrations decreased from week to week for all treatments from Week 2 to Week 6. At Week 6, levels in bedded packs with shredded paper were higher ( < 0.05) than bedded packs containing wood shavings, wood chips, or switchgrass ( < 0.05). At Weeks 4, 5, and 6, concentrations in bedded packs with wood shavings were lower ( < 0.05) than bedded packs of all treatments except wood chips. Results of this study indicate that ground corn cobs or shredded paper may increase odor production and shredded paper may increase when used in deep-bedded livestock facilities, whereas wood shavings may have the least impact on air quality and . PMID:23673740

  7. Investigation of the effects of some drugs and phenolic compounds on human dihydrofolate reductase activity.

    PubMed

    Aslan, Erdem; Adem, Sevki

    2015-03-01

    Dihydrofolate reductase (DHFR) plays a fundamental role in cellular metabolism and cell growth. Inhibition of this enzyme will cause a decrease in the amount of folate that occurs in many metabolic processes, and the deficiency of which may cause various diseases. This study investigated the effects of some drugs and phenolic compounds on DHFR activity in vitro. To determine the inhibitory effect of compounds, enzyme activity was measured with a final concentration of an inhibitor ranging from 10 μM to 51 mM. DHFR was inhibited effectively by naringin, ferulic acid, and levofloxacin with IC50 values under 660 μM. Syringic acid, cefepime, ceftizoxime, cefazolin, ceftriaxone, and ceftazidime exhibited inhibitory effects on the enzyme activity with IC50 values in the range of 3.840-30.224 mM. K(i) constants were calculated using the Cheng-Prusoff equation. K(i) constants calculated in the range of 0.009-2.024 mM with respect to nicotinamide adenine dinucleotide phosphate oxidase (NADPH) and in the range of 0.060-5.830 mM about FH2.

  8. Determinants of Residential Adult Education Effectiveness.

    ERIC Educational Resources Information Center

    Kafka, James J.

    Advocates of residential education have isolated three determinants of residential adult education effectiveness: isolation from the outside environment; concentration on content; and group support. This study investigated the independent and collective relationships of different levels of these determinants with cognitive gain and posttest…

  9. Effects of Compound Configuration on Stimulus Selection in the Pigeon

    ERIC Educational Resources Information Center

    Leith, Charles R.; Maki, William S., Jr.

    1977-01-01

    Whether a stimulus compound is separable or integral has predictable consequences for several human information processing tasks. The purpose of these experiments was to explore the implications of this distinction for research in animal learning and the development of learning theory. (Author/RK)

  10. Sublexical Ambiguity Effect in Reading Chinese Disyllabic Compounds

    ERIC Educational Resources Information Center

    Huang, Hsu-Wen; Lee, Chia-Ying; Tsai, Jie-Li; Tzeng, Ovid J.-L.

    2011-01-01

    For Chinese compounds, neighbors can share either both orthographic forms and meanings, or orthographic forms only. In this study, central presentation and visual half-field (VF) presentation methods were used in conjunction with ERP measures to investigate how readers solve the sublexical semantic ambiguity of the first constituent character in…

  11. Effect of volatile organic compounds from bacteria on nematodes.

    PubMed

    Xu, You-Yao; Lu, Hao; Wang, Xin; Zhang, Ke-Qin; Li, Guo-Hong

    2015-09-01

    The five studied bacterial strains could produce volatile organic compounds (VOCs) that kill nematodes. Based on their 16S rRNA sequences, these strains were identified as Pseudochrobactrum saccharolyticum, Wautersiella falsenii, Proteus hauseri, Arthrobacter nicotianae, and Achromobacter xylosoxidans. The bacterial VOCs were extracted using solid-phase micro-extraction (SPME) and subsequently identified by GC/MS analysis. The VOCs covered a wide range of aldehydes, ketones, alkyls, alcohols, alkenes, esters, alkynes, acids, ethers, as well as heterocyclic and phenolic compounds. Among the 53 VOCs identified, 19 candidates, produced by different bacteria, were selected to test their nematicidal activity (NA) against Caenorhabditis elegans and Meloidogyne incognita. The seven compounds with the highest NAs were acetophenone, S-methyl thiobutyrate, dimethyl disulfide, ethyl 3,3-dimethylacrylate, nonan-2-one, 1-methoxy-4-methylbenzene, and butyl isovalerate. Among them, S-methyl thiobutyrate showed a stronger NA than the commercial insecticide dimethyl disulfide. It was reported for the first time here that the five bacterial strains as well as S-methyl thiobutyrate, ethyl 3,3-dimethylacrylate, 1-methoxy-4-methylbenzene, and butyl isovalerate possess NA. These strains and compounds might provide new insights in the search for novel nematicides.

  12. Regional atmospheric emissions determined from measurements at Jeju Island, Korea: Halogenated compounds from China

    NASA Astrophysics Data System (ADS)

    Kim, Jooil; Li, Shanlan; Kim, Kyung-Ryul; Stohl, Andreas; Mühle, Jens; Kim, Seung-Kyu; Park, Mi-Kyung; Kang, Dong-Jin; Lee, Gangwoong; Harth, Christina M.; Salameh, Peter K.; Weiss, Ray F.

    2010-06-01

    High-frequency in-situ measurements of a wide range of halogenated compounds including chlorofluorocarbons (CFCs), halons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorinated compounds (PFCs), sulfur hexafluoride (SF6), and other chlorinated and brominated compounds have been made at Gosan (Jeju Island, Korea). Regional emissions of HCFC-22 (CHClF2) calculated from inverse modeling were combined with interspecies correlation methods to estimate national emissions for China, a major emitter of industrial halogenated gases. Our results confirm the signs of successful phase-out of primary ozone-depleting species such as CFCs, halons and many chlorinated or brominated compounds, along with substantial emissions of replacement HCFCs. Emissions derived for HFCs, PFCs, and SF6 were compared to published estimates and found to be a significant fraction of global totals. Overall, Chinese emissions of the halogenated compounds discussed here represent 19(14-17)% and 20(15-26)% of global emissions when evaluated in terms of their Ozone Depletion Potentials and 100-year Global Warming Potentials, respectively.

  13. Determination of pharmaceutical compounds in surface- and ground-water samples by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry

    USGS Publications Warehouse

    Cahill, J.D.; Furlong, E.T.; Burkhardt, M.R.; Kolpin, D.; Anderson, L.G.

    2004-01-01

    Commonly used prescription and over-the-counter pharmaceuticals are possibly present in surface- and ground-water samples at ambient concentrations less than 1 μg/L. In this report, the performance characteristics of a combined solid-phase extraction isolation and high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC–ESI-MS) analytical procedure for routine determination of the presence and concentration of human-health pharmaceuticals are described. This method was developed and used in a recent national reconnaissance of pharmaceuticals in USA surface waters. The selection of pharmaceuticals evaluated for this method was based on usage estimates, resulting in a method that contains compounds from diverse chemical classes, which presents challenges and compromises when applied as a single routine analysis. The method performed well for the majority of the 22 pharmaceuticals evaluated, with recoveries greater than 60% for 12 pharmaceuticals. The recoveries of angiotensin-converting enzyme inhibitors, a histamine (H2) receptor antagonist, and antihypoglycemic compound classes were less than 50%, but were retained in the method to provide information describing the potential presence of these compounds in environmental samples and to indicate evidence of possible matrix enhancing effects. Long-term recoveries, evaluated from reagent-water fortifications processed over 2 years, were similar to initial method performance. Method detection limits averaged 0.022 μg/L, sufficient for expected ambient concentrations. Compound-dependent matrix effects on HPLC/ESI-MS analysis, including enhancement and suppression of ionization, were observed as a 20–30% increase in measured concentrations for three compounds and greater than 50% increase for two compounds. Changing internal standard and more frequent ESI source maintenance minimized matrix effects. Application of the method in the national survey demonstrates that several

  14. Determination of estrogenic compounds in wastewater using liquid chromatography-tandem mass spectrometry with electrospray and atmospheric pressure photoionization following desalting extraction.

    PubMed

    Chen, Hsin-Chang; Kuo, Han-Wen; Ding, Wang-Hsien

    2009-01-01

    Two complementary LC-MS ionization methods, electrospray (ESI) and atmospheric pressure photoionization (APPI), have been optimized to determine three natural estrogenic compounds (estrone, 17beta-estradiol and estriol) and two synthetic estrogenic compounds (17alpha-ethynylestradiol and diethylstilbestrol) in the influent and effluent of wastewater treatment plants (WWTPs). The wastewater samples were first subjected to solid-phase extraction coupled with desalting extraction to remove matrix interference. The analytes were then detected using liquid chromatography-tandem mass spectrometry (LC-MS-MS) with ESI and dopant-assisted (DA) APPI to evaluate the ion suppression effect and to complement the detection and quantification of estrogenic compounds in complex wastewater samples. The average ion suppression factors for the extracts of the WWTP influent analyzed using ESI and APPI were 52+/-5% and 27+/-7%, respectively. The sensitivity and ionization efficiency of the LC-ESI-MS-MS system decreased dramatically when a complex matrix was present in the WWTP influent sample. Estrogenic compounds could be detected in the WWTP influent and effluent samples at concentrations below the parts-per-billion level. The lower detection limits obtained when using ESI and the higher matrix tolerance of the APPI method allowed the complete quantification of estrogenic compounds in very complex samples in a complementary manner.

  15. Determination of estrogenic compounds in wastewater using liquid chromatography-tandem mass spectrometry with electrospray and atmospheric pressure photoionization following desalting extraction.

    PubMed

    Chen, Hsin-Chang; Kuo, Han-Wen; Ding, Wang-Hsien

    2009-01-01

    Two complementary LC-MS ionization methods, electrospray (ESI) and atmospheric pressure photoionization (APPI), have been optimized to determine three natural estrogenic compounds (estrone, 17beta-estradiol and estriol) and two synthetic estrogenic compounds (17alpha-ethynylestradiol and diethylstilbestrol) in the influent and effluent of wastewater treatment plants (WWTPs). The wastewater samples were first subjected to solid-phase extraction coupled with desalting extraction to remove matrix interference. The analytes were then detected using liquid chromatography-tandem mass spectrometry (LC-MS-MS) with ESI and dopant-assisted (DA) APPI to evaluate the ion suppression effect and to complement the detection and quantification of estrogenic compounds in complex wastewater samples. The average ion suppression factors for the extracts of the WWTP influent analyzed using ESI and APPI were 52+/-5% and 27+/-7%, respectively. The sensitivity and ionization efficiency of the LC-ESI-MS-MS system decreased dramatically when a complex matrix was present in the WWTP influent sample. Estrogenic compounds could be detected in the WWTP influent and effluent samples at concentrations below the parts-per-billion level. The lower detection limits obtained when using ESI and the higher matrix tolerance of the APPI method allowed the complete quantification of estrogenic compounds in very complex samples in a complementary manner. PMID:18996561

  16. Dioxins and dioxin-like compounds in composts and digestates from European countries as determined by the in vitro bioassay and chemical analysis.

    PubMed

    Beníšek, Martin; Kukučka, Petr; Mariani, Giulio; Suurkuusk, Gert; Gawlik, Bernd M; Locoro, Giovanni; Giesy, John P; Bláha, Luděk

    2015-03-01

    Aerobic composting and anaerobic digestion plays an important role in reduction of organic waste by transforming the waste into humus, which is an excellent soil conditioner. However, applications of chemical-contaminated composts on soils may have unwanted consequences such as accumulation of persistent compounds and their transfer into food chains. The present study investigated burden of composts and digestates collected in 16 European countries (88 samples) by the compounds causing dioxin-like effects as determined by use of an in vitro transactivation assay to quantify total concentrations of aryl hydrocarbon receptor-(AhR) mediated potency. Measured concentrations of 2,3,7,8-Tetrachlorodibeno-p-dioxin (2,3,7,8-TCDD) equivalents (TEQbio) were compared to concentrations of polycyclic aromatic hydrocarbons (PAHs) and selected chlorinated compounds, including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), co-planar polychlorinated biphenyls (PCBs), indicator PCB congeners and organochlorine pesticides (OCPs). Median concentrations of TEQbio (dioxin-like compounds) determined by the in vitro assay in crude extracts of various types of composts ranged from 0.05 to 1.2 with a maximum 8.22μg (TEQbio)kg(-1) dry mass. Potencies were mostly associated with less persistent compounds such as PAHs because treatment with sulfuric acid removed bioactivity from most samples. The pan-European investigation of contamination by organic contaminants showed generally good quality of the composts, the majority of which were in compliance with conservative limits applied in some countries. Results demonstrate performance and added value of rapid, inexpensive, effect-based monitoring, and points out the need to derive corresponding effect-based trigger values for the risk assessment of complex contaminated matrices such as composts. PMID:25522853

  17. Dioxins and dioxin-like compounds in composts and digestates from European countries as determined by the in vitro bioassay and chemical analysis.

    PubMed

    Beníšek, Martin; Kukučka, Petr; Mariani, Giulio; Suurkuusk, Gert; Gawlik, Bernd M; Locoro, Giovanni; Giesy, John P; Bláha, Luděk

    2015-03-01

    Aerobic composting and anaerobic digestion plays an important role in reduction of organic waste by transforming the waste into humus, which is an excellent soil conditioner. However, applications of chemical-contaminated composts on soils may have unwanted consequences such as accumulation of persistent compounds and their transfer into food chains. The present study investigated burden of composts and digestates collected in 16 European countries (88 samples) by the compounds causing dioxin-like effects as determined by use of an in vitro transactivation assay to quantify total concentrations of aryl hydrocarbon receptor-(AhR) mediated potency. Measured concentrations of 2,3,7,8-Tetrachlorodibeno-p-dioxin (2,3,7,8-TCDD) equivalents (TEQbio) were compared to concentrations of polycyclic aromatic hydrocarbons (PAHs) and selected chlorinated compounds, including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), co-planar polychlorinated biphenyls (PCBs), indicator PCB congeners and organochlorine pesticides (OCPs). Median concentrations of TEQbio (dioxin-like compounds) determined by the in vitro assay in crude extracts of various types of composts ranged from 0.05 to 1.2 with a maximum 8.22μg (TEQbio)kg(-1) dry mass. Potencies were mostly associated with less persistent compounds such as PAHs because treatment with sulfuric acid removed bioactivity from most samples. The pan-European investigation of contamination by organic contaminants showed generally good quality of the composts, the majority of which were in compliance with conservative limits applied in some countries. Results demonstrate performance and added value of rapid, inexpensive, effect-based monitoring, and points out the need to derive corresponding effect-based trigger values for the risk assessment of complex contaminated matrices such as composts.

  18. Headspace-liquid phase microextraction for attenuated total reflection infrared determination of volatile organic compounds at trace levels.

    PubMed

    Gonzálvez, Ana; Garrigues, Salvador; Armenta, Sergio; de la Guardia, Miguel

    2010-04-01

    A combination of headspace (HS) sampling and liquid phase microextraction (LPME) has been successfully developed to solve sensitivity problems in attenuated total reflection (ATR) infrared determination of volatile organic compounds (VOCs). The HS sampling facilitates the selective extraction of the target volatile analytes from the sample matrix, while the liquid phase microextraction allows their preconcentration prior to infrared analysis. The direct determination of extracted analytes in the acceptor solvent provides high preconcentration factors of the order of 200 with a reduced consumption of organic solvents and a minimum generation of wastes, being thus the developed methodology a green alternative method. The qualitative and quantitative capability of the proposed approach has been evaluated on the basis of two different examples: (i) screening of benzene, toluene and xylene (BTX) compounds in soil samples and (ii) quantitative determination of toluene in cosmetic nail products.

  19. Effect of concentration temperature on some bioactive compounds and antioxidant proprieties of date syrup.

    PubMed

    Abbès, Fatma; Besbes, Souhail; Brahim, Bchir; Kchaou, Wissal; Attia, Hamadi; Blecker, Christophe

    2013-08-01

    The effect of the concentration temperature on the antioxidant activity, carotenoid and phenolic compounds of date syrup was investigated. Date juice was concentrated at 100  and at "60  in vacuum". After concentration, total phenolic, tannin, non-tannin, flavonoid and carotenoid content were determined spectrophotometrically and high-performance liquid chromatography was used for determination of 5-Hydroxymethyl-2-furfuraldehyde content. The antioxidant activity of date syrup was evaluated by various antioxidant methods including total antioxidant, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging test, ferric reducing antioxidant power and β-carotene bleaching. All date syrups showed strong antioxidant activity accompanied by high total phenolic contents. Results showed that concentration at 100  significantly enhanced the antioxidant activities and total phenolic contents of date syrups compared to vacuum concentration at 60 . A good correlation between the antioxidant activity and total phenolic content and flavonoid was observed. PMID:23729415

  20. Determination of Monod kinetics of toxic compounds by respirometry for structure-biodegradability relationships

    SciTech Connect

    Govind, R.; Desai, S.; Tabak, H.H.

    1990-01-01

    The key to the evaluation of the fate of toxic organic chemicals in the environment is dependant on evaluating their susceptibility to biodegradation. Biodegradation is one of the most important mechanisms in controlling the concentration of chemicals in an aquatic system because toxic pollutants can be mineralized and rendered harmless. Experiments using an electrolytic respirometer have been conducted to collect oxygen consumption data of toxic compounds from the list of RCRA and RCRA land banned chemicals (phenols and phthalates). The estimation of Monod kinetic parameters were obtained for all the compounds by a graphical method. The first order kinetic constants for the substituted phenols were related to the structure of the compounds by the group contribution method.

  1. Determination of musks and other fragrance compounds at ng/L levels using CLSA (closed loop stripping analysis) and GC/MS detection.

    PubMed

    Mitjans, D; Ventura, F

    2004-01-01

    Closed loop stripping analysis (CLSA), a suitable tool for the determination of volatile and semivolatile compounds at low trace levels (ng/l), has been used to determine and quantify seven selected musks and two fragrances (Acetyl cedrene and Amberonne). The obtained extracts are analyzed by high resolution gas chromatography coupled to mass spectrometry (GC/MS) operating in the SIM mode. Quality parameters such as limit of detection; matrix effects; precision expressed as repeatability and reproducibility relative standard deviations of the method and an estimation of the uncertainty have been evaluated. The method has been applied to the analysis of wastewater effluents, surface water and tap water from different places in Europe. All samples contained differents musks at ng/l levels with the polycyclic musks Galaxolide and Tonalide and both fragrances, Amberonne and Acetyl cedrene, being the most abundant. These results suggest the importance of studying and controlling the presence of these ubiquitous environmental compounds in water systems.

  2. Polar organic marker compounds in atmospheric aerosols: Determination, time series, size distributions and sources

    NASA Astrophysics Data System (ADS)

    Kourtchev, Ivan

    Terrestrial vegetation releases substantial amounts of reactive volatile organic compounds (VOCs; e.g., isoprene, monoterpenes) into the atmosphere. The VOCs can be rapidly photooxidized under conditions of high solar radiation, yielding products that can participate in new particle formation and growth processes above forests. This thesis focuses on the characterization, identification and quantification of oxidation products of biogenic VOC (BVOCs) as well as other species (tracer compounds) that provide information on aerosol sources and source processes. Atmospheric aerosols from various forested sites (i.e., Hyytiala, southern Finland; Rondonia, Brazil; K-Puszta, Hungary and Julich, Germany) were analyzed with Gas Chromotography/Mass Spectrometry (GC/MS) using analytical procedure that targets polar organic compounds. The study demonstrated that isoprene (i.e., 2-methyerythritol, 2-methylthreitol, 2-methylglyceric acid and C5-alkene triols (2-methyl-1,3,4-trihydroxy-l-butene (cis and trans) and 3 methyl-2,3,4-trihydroxy-1-butene)) and monoterpene (pinic acid, norpinic acid, 3-hydroxyglutaric acid and 3-methyl-1,2,3-butanetricarboxylic acid) oxidation products were present in substantial concentrations in atmospheric aerosols suggesting that oxidation of BVOC from the vegetation is an important process in all studied sites. On the other hand, presence of levoglucosan, biomass burning marker, especially in Amazonian rain forest site at Rondonia, Brazil, pointed that all sites were affected by anthropogenic activities, namely biomass burning. Other identified compounds included plyols, arabitol, mannitol and erythritol, which are marker compounds for fungal spores and monosacharides, glucose and fructose, markers for plant polens. Temporal variations as well as mass size distributions of the detected species confirmed the possible formation mechanisms of marker compounds.

  3. Quantitative determination of secoiridoid and gamma-pyrone compounds in Gentiana lutea cultured in vitro.

    PubMed

    Menković, N; Savikin-Fodulović, K; Momcilović, I; Grubisić, D

    2000-02-01

    The production of secondary metabolites was studied in shoots, roots, and hairy roots of Gentiana lutea obtained in vitro. In shoots, both secoiridoid and gamma-pyrone compounds were detected in amounts similar to those found in aerial parts of plants collected from nature. The most abundant secoiridoid was gentiopicrin while mangiferin was the main compound among the gamma-pyrones. The adventitious roots obtained in vitro showed a poor biosynthetic capacity. Upon infection with Agrobacterium rhizogenes, nine hairy root clones were established which differed in the amount of secondary metabolites.

  4. Determining electrically evoked compound action potential thresholds: A comparison of computer versus human analysis methods

    PubMed Central

    Glassman, E. Katelyn; Hughes, Michelle L.

    2012-01-01

    Objectives Current cochlear implants (CIs) have telemetry capabilities for measuring the electrically evoked compound action potential (ECAP). Neural Response Telemetry (NRT™; Cochlear) and Neural Response Imaging (NRI; Advanced Bionics [AB]) can measure ECAP responses across a range of stimulus levels to obtain an amplitude growth function. Software-specific algorithms automatically mark the leading negative peak, N1, and the following positive peak/plateau, P2, and apply linear regression to estimate ECAP threshold. Alternatively, clinicians may apply expert judgments to modify the peak markers placed by the software algorithms, and/or use visual detection to identify the lowest level yielding a measurable ECAP response. The goals of this study were to: (1) assess the variability between human and computer decisions for (a) marking N1 and P2, and (b) determination of linear regression threshold (LRT) and visual detection threshold (VDT); and (2) compare LRT and VDT methods within and across human and computer decision methods. Design ECAP amplitude growth functions were measured for three electrodes in each of 20 ears (10 Cochlear Nucleus® 24RE/CI512, and 10 AB CII/90K). LRT, defined as the current level yielding an ECAP with zero amplitude, was calculated for both computer- (C-LRT) and human-picked peaks (H-LRT). VDT, defined as the lowest level resulting in a measurable ECAP response, was also calculated for both computer- (C-VDT) and human-picked peaks (H-VDT). Because NRI assigns peak markers to all waveforms but does not include waveforms with amplitudes less than 20 μV in its regression calculation, C-VDT for AB subjects was defined as the lowest current level yielding an amplitude ≥20 μV. Results Overall, there were significant correlations between human and computer decisions for peak-marker placement, LRT, and VDT for both manufacturers (r = 0.78 to 1.00, p < 0.001). For Cochlear devices, LRT and VDT correlated equally well for both computer- and

  5. Analytical strategies based on chromatography-mass spectrometry for the determination of estrogen-mimicking compounds in food.

    PubMed

    Capriotti, Anna Laura; Cavaliere, Chiara; Colapicchioni, Valentina; Piovesana, Susy; Samperi, Roberto; Laganà, Aldo

    2013-10-25

    Food safety can be compromised by the presence of a wide variety of substances, deriving from both natural and anthropogenic sources. Among these substances, compounds exhibiting various degrees of estrogenic activity have been widely studied in environmental samples, whereas less attention has been devoted to food matrices. The aim of the present review is to give a general overview on the recent analytical methods based on gas or liquid chromatography coupled to mass spectrometry for the determination of estrogen-like compounds in foods, including new developments, improvements and upcoming trends in the field. Attention will be focused on four representative groups of compounds, i.e. natural and synthetic estrogens, mycoestrogens, phytoestrogens, and alkylphenols.

  6. Inherent organic compounds in biochar--Their content, composition and potential toxic effects.

    PubMed

    Buss, Wolfram; Mašek, Ondřej; Graham, Margaret; Wüst, Dominik

    2015-06-01

    Pyrolysis liquids consist of thermal degradation products of biomass in various stages of its decomposition. Therefore, if biochar gets affected by re-condensed pyrolysis liquids it is likely to contain a huge variety of organic compounds. In this study the chemical composition of such compounds associated with two contaminated, high-volatile organic compound (VOC) biochars were investigated and compared with those for a low-VOC biochar. The water-soluble organic compounds with the highest concentrations in the two high-VOC biochars were acetic, formic, butyric and propionic acids; methanol, phenol, o-, m- and p-cresol, and 2,4-dimethylphenol, all with concentrations over 100 μg g(-1). The concentrations of 16 US EPA PAHs determined by 36 h toluene extractions were 6.09 μg g(-1) for the low-VOC biochar. For high-VOC biochar the total concentrations were 53.42 μg g(-1) and 27.89 μg g(-1), while concentrations of water-soluble PAHs ranged from 1.5 to 2 μg g(-1). Despite the concentrations of PAHs exceeding biochar guideline values, it was concluded that, for these particular biochars, the biggest concern for application to soil would be the co-occurrence of VOCs such as low molecular weight (LMW) organic acids and phenols, as these can be highly mobile and have a high potential to cause phytotoxic effects. Therefore, based on results of this study we strongly suggest for VOCs to be included among criteria for assessment of biochar quality.

  7. Sexually Dimorphic Effects of Cannabinoid Compounds on Emotion and Cognition

    PubMed Central

    Rubino, Tiziana; Parolaro, Daniela

    2011-01-01

    This review addresses the issue of sex differences in the response to cannabinoid compounds focusing mainly on behaviors belonging to the cognitive and emotional sphere. Sexual dimorphism exists in the different components of the endocannabinoid system. Males seem to have higher CB1 receptor binding sites than females, but females seem to possess more efficient CB1 receptors. Differences between sexes have been also observed in the metabolic processing of THC, the main psychoactive ingredient of marijuana. The consistent dimorphism in the endocannabinoid system and THC metabolism may justify at least in part the different sensitivity observed between male and female animals in different behavioral paradigms concerning emotion and cognition after treatment with cannabinoid compounds. On the basis of these observations, we would like to emphasize the need of including females in basic research and to analyze results for sex differences in epidemiological studies. PMID:21991251

  8. Simultaneous determination of bioactive marker compounds from Gardeniae fructus by high performance liquid chromatography.

    PubMed

    Lee, Eun Ju; Hong, Jun Kee; Whang, Wan Kyunn

    2014-08-01

    Gardeniae fructus is one of the medicinal herbs that have been used in Far Eastern countries, such as Korea, China, and Japan. Gardeniae fructus is the dried ripe fruit of Gardenia jasminoides Ellis (Rubiaceae) and has been used as a yellow dye. It is widely used as traditional herbal medicine for reducing fever, cholagogue, diuretic and antiphlogistic effects. We established an analytical method that was useful to evaluate the quality control, and standardize quantification monitoring of 68 samples of Gardeniae fructus collected from Korea and China. While numerous previous studies have focused on the simultaneous analysis of geniposide, which constitutes the higher proportion of Gardeniae fructus, and crocin, which determines its color, no simultaneous analysis of gardenoside and geniposide, the major components of Gardeniae Fructus, has been performed. However, previously reported methods are not considered accurate enough because only geniposide or gardenoside was chosen to be the marker component for the quality control of Gardeniae fructus. Thus, we developed the method using simultaneous determination of four components including geniposide, gardenoside, geniposic acid and chlorogenic acid. Against this backdrop, this study aims to propose a new calculation for gardenoside and geniposide concentrations by analyzing their concentrations in Gardeniae fructus. PMID:24277694

  9. Simultaneous Determination of Amiloride and Hydrochlorothiazide in a Compound Tablet by Diffuse Reflectance Spectroscopy and Chemometrics

    NASA Astrophysics Data System (ADS)

    Tang, J.; Li, X.; Feng, Y.; Liang, B.

    2016-09-01

    This paper studies the simultaneous determination of amiloride hydrochloride (AMH) and hydrochlorothiazide (HCTZ) in amiloride hydrochloride tablets by ultraviolet-visible-shortwave near-infrared diffuse reflectance spectroscopy (UV-Vis-swNIR DRS) and chemometrics. Quantitative models for the two components were established by partial least squares (PLS) and support vector regression (SVR), respectively. For the PLS models of AMH and HCTZ, the determination coefficient R2 of the calibration set was 0.9503 and 0.9538, and the coefficient R2 of the prediction set was 0.8983 and 0.9260, respectively. The root mean square error of the calibration set (RMSEC) was 0.8 mg and 8.1 mg, while the root mean square error of the prediction set (RMSEP) was 1.0 mg and 8.7 mg, respectively. For the SVR models of AMH and HCTZ, the R2 of the calibration set was 0.9668 and 0.9609; the R2 of the prediction set was 0.9145 and 0.9446, respectively. The RMSEC was 0.7 and 7.5 mg, and the RMSEP was 0.9 and 8.9 mg, respectively. The results show that SVR modeling has a satisfactory prediction effect. The proposed method based on UV-vis-swNIR and chemometrics is efficient, nondestructive, and expected to be used for online quality monitoring in the production of drugs.

  10. Off-axis aberration effect on beamwidth in multitarget compounding system

    NASA Astrophysics Data System (ADS)

    Shi, Yaotao; Hu, Haili; Zuo, Baojun; Fan, Zhigang; Yu, Cuiping

    2014-09-01

    Multitarget compounding system is a decisive subsystem of the infrared hardware-in-the-loop simulation system and the concentric structure with dimpled mirror is a potential multitarget compounding system. By inducting the off-axis aberration, the effect of off-axis aberration on broadening beamwidth was investigated for the practical multitarget compounding system. A critical abaxial distance was found when the axial spherical aberration was equal to the focal length of small mirrors. Outgoing beamwidth was increasing with abaxial distances when abaxial distance was over the critical distance. A laboratory multitarget compounding system was designed to demonstrate the effect.

  11. Moooving forward on determining biologically active compounds in milk and their impact on health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent studies have demonstrated that some of the lesser studied components in milk, known as biologically active compounds (BACs), may provide potential benefits to human health. The added health-value of raw milk and milk from organic and grass-fed herds is strongly debated because of limited, an...

  12. [Determination of three ester compounds in gasoline by two-dimensional gas chromatography].

    PubMed

    Zhao, Yan; Xu, Dongyu; Lin, Haoxue; Chen, Xiaoyan; Chen, Zeyong

    2014-06-01

    A simple and efficient method based on the technique of packed column switching-back flushing was established for the analysis of the ester compounds (including ethyl acetate, sec-butyl acetate, dimethyl carbonate) in gasoline. With the use of a non-polar pre-column, we successfully separated the components in gasoline by back flushing out components heavier than n-octane, while the lighter components and the ester compounds were flushed into a polar analytical column. In this method, external standard method was applied for quantification. As a result, good linear relationships existed among the three ester compounds in the range of 50 mg/L to 50 000 mg/L. The linear correlation coefficients (r2) for ethyl acetate, sec-butyl acetate and dimethyl carbonate were 0.999 99, 1.000 00 and 0.999 95, respectively. The relative standard deviations (RSDs) of standard samples in six continuous tests were within 1.0%. The recoveries were between 98.7% and 107.9%. The detection limit of the method (S/N = 3) was 5 mg/L. No pretreatment was needed. This method is simple, accurate, quick as well as efficient, and can be used as an ideal method for the analysis of the ester compounds in gasoline. PMID:25269268

  13. Determination of dimethyl selenide and dimethyl sulphide compounds causing off-flavours in bottled mineral waters.

    PubMed

    Guadayol, Marta; Cortina, Montserrat; Guadayol, Josep M; Caixach, Josep

    2016-04-01

    Sales of bottled drinking water have shown a large growth during the last two decades due to the general belief that this kind of water is healthier, its flavour is better and its consumption risk is lower than that of tap water. Due to the previous points, consumers are more demanding with bottled mineral water, especially when dealing with its organoleptic properties, like taste and odour. This work studies the compounds that can generate obnoxious smells, and that consumers have described like swampy, rotten eggs, sulphurous, cooked vegetable or cabbage. Closed loop stripping analysis (CLSA) has been used as a pre-concentration method for the analysis of off-flavour compounds in water followed by identification and quantification by means of GC-MS. Several bottled water with the aforementioned smells showed the presence of volatile dimethyl selenides and dimethyl sulphides, whose concentrations ranged, respectively, from 4 to 20 ng/L and from 1 to 63 ng/L. The low odour threshold concentrations (OTCs) of both organic selenide and sulphide derivatives prove that several objectionable odours in bottled waters arise from them. Microbial loads inherent to water sources, along with some critical conditions in water processing, could contribute to the formation of these compounds. There are few studies about volatile organic compounds in bottled drinking water and, at the best of our knowledge, this is the first study reporting the presence of dimethyl selenides and dimethyl sulphides causing odour problems in bottled waters. PMID:26852288

  14. Determination of dimethyl selenide and dimethyl sulphide compounds causing off-flavours in bottled mineral waters.

    PubMed

    Guadayol, Marta; Cortina, Montserrat; Guadayol, Josep M; Caixach, Josep

    2016-04-01

    Sales of bottled drinking water have shown a large growth during the last two decades due to the general belief that this kind of water is healthier, its flavour is better and its consumption risk is lower than that of tap water. Due to the previous points, consumers are more demanding with bottled mineral water, especially when dealing with its organoleptic properties, like taste and odour. This work studies the compounds that can generate obnoxious smells, and that consumers have described like swampy, rotten eggs, sulphurous, cooked vegetable or cabbage. Closed loop stripping analysis (CLSA) has been used as a pre-concentration method for the analysis of off-flavour compounds in water followed by identification and quantification by means of GC-MS. Several bottled water with the aforementioned smells showed the presence of volatile dimethyl selenides and dimethyl sulphides, whose concentrations ranged, respectively, from 4 to 20 ng/L and from 1 to 63 ng/L. The low odour threshold concentrations (OTCs) of both organic selenide and sulphide derivatives prove that several objectionable odours in bottled waters arise from them. Microbial loads inherent to water sources, along with some critical conditions in water processing, could contribute to the formation of these compounds. There are few studies about volatile organic compounds in bottled drinking water and, at the best of our knowledge, this is the first study reporting the presence of dimethyl selenides and dimethyl sulphides causing odour problems in bottled waters.

  15. Comparison of methods for determining volatile compounds in cheese, milk, and whey powder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but selecting the proper procedures presents challenges. Heat is applied to drive volatiles from the samp...

  16. DETERMINATION OF SYNTHETIC MUSK COMPOUNDS IN MUNICIPAL WASTEWATER AND ESTIMATING BIOTA EXPOSURE IN THE RECEIVING WATERS

    EPA Science Inventory

    Synthetic musk compounds are consumer chemicals manufactured as fragrance materials and consumed in very large quantities worldwide. Due to their high usage and release, they have become ubiquitous in the environment. The U.S. EPA (Las Vegas) developed surface water monitoring me...

  17. HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

    PubMed Central

    Uddin, Riaz; Saha, Moni Rani; Subhan, Nusrat; Hossain, Hemayet; Jahan, Ismet Ara; Akter, Raushanara; Alam, Ashraful

    2014-01-01

    Purpose: Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. Methods: Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power and total antioxidant capacity expressed as equivalent to ascorbic acid were employed. Moreover, phenolic compounds were detected by high-performance liquid chromatography (HPLC) coupled with diode-array detection. Results: The methanol extract showed significant free radical scavenging activities in DPPH radical scavenging antioxidant assays compared to the reference antioxidant ascorbic acid. Total antioxidant activity was increased in a dose dependent manner. The extract also showed strong reducing power. The total phenolic content was determined as 190.97 mg/g of gallic acid equivalent. HPLC coupled with diode-array detection was used to identify and quantify the phenolic compounds in the extracts. Gallic acid, (+)-catechin, rutin hydrate and quercetin have been identified in the plant extracts. Among the phenolic compounds, catechin and rutin hydrate are present predominantly in the extract. The accuracy and precision of the presented method were corroborated by low intra- and inter-day variations in quantitative results in leaves extract. Conclusion: These results suggest that phenolic compounds and flavonoids might contribute to high antioxidant activities of Gardenia jasminoides leaves. PMID:24754012

  18. Gas chromatographic determination of some phenolic compounds in fuels and engine oil after simultaneous derivatization and microextraction.

    PubMed

    Farajzadeh, Mir Ali; Yadeghari, Adeleh; Khoshmaram, Leila; Ghorbanpour, Houshang

    2014-10-01

    In this study, a simultaneous derivatization/air-assisted liquid-liquid microextraction method has been developed for sample preparation of some phenolic compounds in fuels and engine oil. Analytes are transferred by back liquid-liquid extraction into NaOH solution and then are derivatized with butyl chloroformate and extracted simultaneously into carbon tetrachloride. The extracted derivatized analytes are analyzed using gas chromatography with flame ionization detection. The effect of extracting solvent type, derivatization agent and extraction solvent volumes, ionic strength of the aqueous solution, number of extraction cycles, etc., on the extraction efficiency is investigated. The calibration graphs are linear in the range of 3-10,000 μg/L. Enhancement factors, enrichment factors, and extraction recoveries are in the ranges of 497 to 1471, 571 to 991, and 60 to 109%, respectively. Detection limits are obtained in the range of 0.8 to 2.0 μg/L. Relative standard deviations for the extraction of each selected phenols are in the ranges of 2-4% for intraday (n = 6) and 3-6% (n = 5) for interday precisions for 200 μg/L. This technique is successfully applied for the extraction, preconcentration, and determination of the selected phenols in gasoline, kerosene, gas oil, and engine oil. PMID:25082460

  19. Gas chromatographic determination of some phenolic compounds in fuels and engine oil after simultaneous derivatization and microextraction.

    PubMed

    Farajzadeh, Mir Ali; Yadeghari, Adeleh; Khoshmaram, Leila; Ghorbanpour, Houshang

    2014-10-01

    In this study, a simultaneous derivatization/air-assisted liquid-liquid microextraction method has been developed for sample preparation of some phenolic compounds in fuels and engine oil. Analytes are transferred by back liquid-liquid extraction into NaOH solution and then are derivatized with butyl chloroformate and extracted simultaneously into carbon tetrachloride. The extracted derivatized analytes are analyzed using gas chromatography with flame ionization detection. The effect of extracting solvent type, derivatization agent and extraction solvent volumes, ionic strength of the aqueous solution, number of extraction cycles, etc., on the extraction efficiency is investigated. The calibration graphs are linear in the range of 3-10,000 μg/L. Enhancement factors, enrichment factors, and extraction recoveries are in the ranges of 497 to 1471, 571 to 991, and 60 to 109%, respectively. Detection limits are obtained in the range of 0.8 to 2.0 μg/L. Relative standard deviations for the extraction of each selected phenols are in the ranges of 2-4% for intraday (n = 6) and 3-6% (n = 5) for interday precisions for 200 μg/L. This technique is successfully applied for the extraction, preconcentration, and determination of the selected phenols in gasoline, kerosene, gas oil, and engine oil.

  20. Chapter 3. Determination of semivolatile organic compounds and polycyclic aromatic hydrocarbons in solids by gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Zaugg, Steven D.; Burkhardt, Mark R.; Burbank, Teresa L.; Olson, Mary C.; Iverson, Jana L.; Schroeder, Michael P.

    2006-01-01

    A method for the determination of 38 polycyclic aromatic hydrocarbons (PAHs) and semivolatile organic compounds in solid samples is described. Samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from the solid sample twice at 13,800 kilopascals; first at 120 degrees Celsius using a water/isopropyl alcohol mixture (50:50, volume-to-volume ratio), and then the sample is extracted at 200 degrees Celsius using a water/isopropyl alcohol mixture (80:20, volume-to-volume ratio). The compounds are isolated using disposable solid-phase extraction (SPE) cartridges containing divinylbenzene-vinylpyrrolidone copolymer resin. The cartridges are dried with nitrogen gas, and then sorbed compounds are eluted from the SPE material using a dichloromethane/diethyl ether mixture (80:20, volume-to-volume ratio) and passed through a sodium sulfate/Florisil SPE cartridge to remove residual water and to further clean up the extract. The concentrated extract is solvent exchanged into ethyl acetate and the solvent volume reduced to 0.5 milliliter. Internal standard compounds are added prior to analysis by capillary-column gas chromatography/mass spectrometry. Comparisons of PAH data for 28 sediment samples extracted by Soxhlet and the accelerated solvent extraction (ASE) method described in this report produced similar results. Extraction of PAH compounds from standard reference material using this method also compared favorably with Soxhlet extraction. The recoveries of PAHs less than molecular weight 202 (pyrene or fluoranthene) are higher by up to 20 percent using this ASE method, whereas the recoveries of PAHs greater than or equal to molecular weight 202 are equivalent. This ASE method of sample extraction of solids has advantages over conventional Soxhlet extraction by increasing automation of the extraction process, reducing extraction time, and using less solvent. Extract cleanup also is greatly simplified because SPE replaces

  1. Rapid screening and quantitative determination of bioactive compounds from fruit extracts of Myristica species and their in vitro antiproliferative activity.

    PubMed

    Pandey, Renu; Mahar, Rohit; Hasanain, Mohammad; Shukla, Sanjeev K; Sarkar, Jayanta; Rameshkumar, K B; Kumar, Brijesh

    2016-11-15

    Efficient and sensitive LC-MS/MS methods have been developed for the rapid screening and determination of bioactive compounds in different fruit parts of four Myristica species, viz., Myristica beddomeii, Myristica fragrans, Myristica fatua and Myristica malabarica. Twenty-one compounds were identified and characterized on the basis of their accurate mass and MS/MS fragmentation pattern using HPLC-QTOF-MS/MS and NMR analysis. Quantitative determination of five major bioactive compounds was performed using multiple-reaction monitoring mode with continuous polarity switching by UHPLC-QqQLIT-MS/MS. Moreover, in vitro antiproliferative activity of these Myristica species was evaluated against five human cancer cell lines A549, DLD-1, DU145, FaDu and MCF-7 using SRB assay. Seventeen phytoconstituents were identified and reported for the first time from M. beddomeii and sixteen from M. fatua. Quantification result showed highest total content of five major bioactive compounds in mace of M. fragrans. Evaluation of in vitro antiproliferative activity revealed potent activity in all investigated species except M. fragrans.

  2. Potential of LC Coupled to Fluorescence Detection in Food Metabolomics: Determination of Phenolic Compounds in Virgin Olive Oil

    PubMed Central

    Monasterio, Romina P.; Olmo-García, Lucía; Bajoub, Aadil; Fernández-Gutiérrez, Alberto; Carrasco-Pancorbo, Alegría

    2016-01-01

    A powerful chromatographic method coupled to a fluorescence detector was developed to determine the phenolic compounds present in virgin olive oil (VOO), with the aim to propose an appropriate alternative to liquid chromatography-mass spectrometry. An excitation wavelength of 285 nm was selected and four different emission wavelengths (316, 328, 350 and 450 nm) were simultaneously recorded, working therefore on “multi-emission” detection mode. With the use of commercially available standards and other standards obtained by semipreparative high performance liquid chromatography, it was possible to identify simple phenols, lignans, several complex phenols, and other phenolic compounds present in the matrix under study. A total of 26 phenolic compounds belonging to different chemical families were identified (23 of them were susceptible of being quantified). The proposed methodology provided detection and quantification limits within the ranges of 0.004–7.143 μg·mL−1 and 0.013–23.810 μg·mL−1, respectively. As far as the repeatability is concerned, the relative standard deviation values were below 0.43% for retention time, and 9.05% for peak area. The developed methodology was applied for the determination of phenolic compounds in ten VOOs, both monovarietals and blends. Secoiridoids were the most abundant fraction in all the samples, followed by simple phenolic alcohols, lignans, flavonoids, and phenolic acids (being the abundance order of the latter chemical classes logically depending on the variety and origin of the VOOs). PMID:27669238

  3. Determination of Dechlorane Plus and related compounds (dechlorane 602, 603 and 604) in fish and vegetable oils.

    PubMed

    Von Eyken, Annie; Pijuan, Lluís; Martí, Ramon; Blanco, Ma José; Díaz-Ferrero, Jordi

    2016-02-01

    Dechlorane Plus (DP) is a flame retardant used as a substitute of Mirex since 1970s, but it was not detected in the environment until 2006. Since then, this compound and its main relatives, Dechlorane 602, 603 and 604, have been mainly studied in environmental matrices for monitoring purposes, but the dietary exposure to them has been hardly investigated so far. In the present study, we determined this family of compounds in fish and vegetable oil samples from Catalonia (Spain), most of them used as health supplements. Determination was carried out by gas chromatography-high resolution mass spectrometry (GC-HRMS), after a clean up in a multilayer silica column and preparative high performance liquid chromatography (HPLC) equipped with a pyrenyl(ethyl) column. Concentrations of Dechlorane compounds were between below the limit of detection and 384.2 pg g(-1). Although there are only few studies about the presence of these pollutants in food or feed, concentrations obtained indicated that these compounds are in the same order in fish and vegetable oil health supplements as the few other food and feed studies.

  4. Potential of LC Coupled to Fluorescence Detection in Food Metabolomics: Determination of Phenolic Compounds in Virgin Olive Oil.

    PubMed

    Monasterio, Romina P; Olmo-García, Lucía; Bajoub, Aadil; Fernández-Gutiérrez, Alberto; Carrasco-Pancorbo, Alegría

    2016-01-01

    A powerful chromatographic method coupled to a fluorescence detector was developed to determine the phenolic compounds present in virgin olive oil (VOO), with the aim to propose an appropriate alternative to liquid chromatography-mass spectrometry. An excitation wavelength of 285 nm was selected and four different emission wavelengths (316, 328, 350 and 450 nm) were simultaneously recorded, working therefore on "multi-emission" detection mode. With the use of commercially available standards and other standards obtained by semipreparative high performance liquid chromatography, it was possible to identify simple phenols, lignans, several complex phenols, and other phenolic compounds present in the matrix under study. A total of 26 phenolic compounds belonging to different chemical families were identified (23 of them were susceptible of being quantified). The proposed methodology provided detection and quantification limits within the ranges of 0.004-7.143 μg·mL(-1) and 0.013-23.810 μg·mL(-1), respectively. As far as the repeatability is concerned, the relative standard deviation values were below 0.43% for retention time, and 9.05% for peak area. The developed methodology was applied for the determination of phenolic compounds in ten VOOs, both monovarietals and blends. Secoiridoids were the most abundant fraction in all the samples, followed by simple phenolic alcohols, lignans, flavonoids, and phenolic acids (being the abundance order of the latter chemical classes logically depending on the variety and origin of the VOOs). PMID:27669238

  5. Rapid screening and quantitative determination of bioactive compounds from fruit extracts of Myristica species and their in vitro antiproliferative activity.

    PubMed

    Pandey, Renu; Mahar, Rohit; Hasanain, Mohammad; Shukla, Sanjeev K; Sarkar, Jayanta; Rameshkumar, K B; Kumar, Brijesh

    2016-11-15

    Efficient and sensitive LC-MS/MS methods have been developed for the rapid screening and determination of bioactive compounds in different fruit parts of four Myristica species, viz., Myristica beddomeii, Myristica fragrans, Myristica fatua and Myristica malabarica. Twenty-one compounds were identified and characterized on the basis of their accurate mass and MS/MS fragmentation pattern using HPLC-QTOF-MS/MS and NMR analysis. Quantitative determination of five major bioactive compounds was performed using multiple-reaction monitoring mode with continuous polarity switching by UHPLC-QqQLIT-MS/MS. Moreover, in vitro antiproliferative activity of these Myristica species was evaluated against five human cancer cell lines A549, DLD-1, DU145, FaDu and MCF-7 using SRB assay. Seventeen phytoconstituents were identified and reported for the first time from M. beddomeii and sixteen from M. fatua. Quantification result showed highest total content of five major bioactive compounds in mace of M. fragrans. Evaluation of in vitro antiproliferative activity revealed potent activity in all investigated species except M. fragrans. PMID:27283658

  6. Effect of temperature on the chromatographic retention of ionizable compounds. II. Acetonitrile-water mobile phases.

    PubMed

    Gagliardi, Leonardo G; Castells, Cecilia B; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2005-06-10

    The retentive behavior of weak acids and bases in reversed-phase liquid chromatography (RPLC) upon changes in column temperature has been theoretically and experimentally studied. The study focuses on examining the temperature dependence of the retention of various solutes at eluent pH close to their corresponding pKa values, and on the indirect role exerted by the buffer ionization equilibria on retention and selectivity. Retention factors of several ionizable compounds in a typical octadecylsilica column and using buffer solutions dissolved in 30% (v/v) acetonitrile as eluent at five temperatures in the range from 25 to 50 degrees C were carefully measured. Six buffer solutions were prepared from judiciously chosen conjugated pairs of different chemical nature. Their pKa values in this acetonitrile-water composition and within the range of 15-50 degrees C were determined potentiometrically. These compounds exhibit very different standard ionization enthalpies within this temperature range. Thus, whenever they are used to control mobile phase pH, the column temperature determines their final pH. Predictive equations of retention that take into account the temperature effect on both the transfer and the ionization processes are evaluated. This study demonstrates the significant role that the selected buffer would have on retention and selectivity in RPLC at temperatures higher than 25 degrees C, particularly for solutes that coelute. PMID:16001552

  7. Effect of temperature on the chromatographic retention of ionizable compounds. II. Acetonitrile-water mobile phases.

    PubMed

    Gagliardi, Leonardo G; Castells, Cecilia B; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2005-06-10

    The retentive behavior of weak acids and bases in reversed-phase liquid chromatography (RPLC) upon changes in column temperature has been theoretically and experimentally studied. The study focuses on examining the temperature dependence of the retention of various solutes at eluent pH close to their corresponding pKa values, and on the indirect role exerted by the buffer ionization equilibria on retention and selectivity. Retention factors of several ionizable compounds in a typical octadecylsilica column and using buffer solutions dissolved in 30% (v/v) acetonitrile as eluent at five temperatures in the range from 25 to 50 degrees C were carefully measured. Six buffer solutions were prepared from judiciously chosen conjugated pairs of different chemical nature. Their pKa values in this acetonitrile-water composition and within the range of 15-50 degrees C were determined potentiometrically. These compounds exhibit very different standard ionization enthalpies within this temperature range. Thus, whenever they are used to control mobile phase pH, the column temperature determines their final pH. Predictive equations of retention that take into account the temperature effect on both the transfer and the ionization processes are evaluated. This study demonstrates the significant role that the selected buffer would have on retention and selectivity in RPLC at temperatures higher than 25 degrees C, particularly for solutes that coelute.

  8. Determination of regulatory organic compounds in radioactive waste samples. Semivolatile organics in aqueous liquids

    SciTech Connect

    Tomkins, B.A.; Caton, J.E. Jr.; Fleming, G.S.; Garcia, M.E.; Harmon, S.H.; Schenley, R.L.; Treese, C.A.; Griest, W.H. )

    1990-02-01

    The regulatory semivolatile organic compounds present in radioactive aqueous waste samples are extracted and concentrated in a small-scale version of a standard EPA procedure normally used for ground waters. Decontamination is sufficient to permit analysis of the extract in a conventional gas chromatography/mass spectrometry laboratory. The performance of the modified procedure, based on surrogate standards, matrix spikes and matrix spike duplicates, and blanks, is comparable to that of the standard method. The modified procedure was applied to a variety of aqueous radioactive waste tank samples. Only 12 of the EPA Appendix VIII compounds were present, and none in concentrations exceeding the reporting limit (500 or 2,500 {mu}g/L). The most common semivolatile present was tributyl phosphate, an organic extractant commonly used in radiochemical processing, at 2,000-30,000 {mu}g/L.

  9. Determination of descriptors for fragrance compounds by gas chromatography and liquid-liquid partition.

    PubMed

    Karunasekara, Thushara; Poole, Colin F

    2012-04-27

    Retention factors on a minimum of eight stationary phases at various temperatures by gas-liquid chromatography and liquid-liquid partition coefficients for five totally organic biphasic systems were combined to estimate descriptors for 28 fragrance compounds with an emphasis on compounds that are known or potential allergens. The descriptors facilitated the estimation of several properties of biological and environmental interest (sensory irritation threshold, odor detection threshold, nasal pungency threshold, skin permeability from water, skin-water partition coefficients, octanol-water partition coefficients, absorption by air particles, adsorption by diesel soot particles, air-water partition coefficients, and adsorption by film water). The descriptors are suitable for use in the solvation parameter model and facilitate the estimation of a wide range of physicochemical, chromatographic, biological, and environmental properties using existing models.

  10. An approach to determination of phenolic compounds in seawater using SPME-GC-MS based on SWCNTs coating

    NASA Astrophysics Data System (ADS)

    Zhu, Jia; Wang, Ying; Zeng, Lin

    2016-08-01

    Phenolic compounds have become one kind of the important pollutants of the marine environment. Single-walled Carbon nanotubes, as one-dimensional nano materials, have light weight and perfect hexagonal structure of connections, with many unusual mechanical, chemical and electrical properties. In recent years, with the research of carbon nanotubes and other nano materials, the application prospect is also constantly discussed. In this paper, homemade single-walled carbon nanotubes (SWCNTs) coating was used for establishing an analytical approach to the determination of five kinds of phenolic compounds in seawater using SPME-GC-MS. Optimal conditions: After saturation was conducted with NaCl, and pH was adjusted to 2.0 with H2SO4, the extract was immersed in a water bath at 40°C for GC-MS determination through 40-min agitating extraction at 500 rmin-1 and 3-min desorption at 280°C. The liniearities ranged between 0.01-100 μg L-1, and the determination limits ranged between 1.5-10 ng L-1. The relative standard deviation (RSD, n = 5) was less than 6.5%. For the phenolic compounds obtained from the spiked recovery test for actual seawater samples, the rates of recovery were 87.5%-101.7%, and the RSDs were less than 8.8%, which met the requirements of determination. Due to its simplicity, high efficiency and low consumption, this approach is suitable for the analysis of trace amounts of phenolic compounds in marine waters.

  11. Evaluation of a Silicone Membrane as an Alternative to Human Skin for Determining Skin Permeation Parameters of Chemical Compounds.

    PubMed

    Uchida, Takashi; Yakumaru, Masafumi; Nishioka, Keisuke; Higashi, Yoshihiro; Sano, Tomohiko; Todo, Hiroaki; Sugibayashi, Kenji

    2016-01-01

    We evaluated the effectiveness of a silicone membrane as an alternative to human skin using the skin permeation parameters of chemical compounds. An in vitro permeation study using 15 model compounds was conducted, and permeation parameters comprising permeability coefficient (P), diffusion parameter (DL(-2)), and partition parameter (KL) were calculated from each permeation profile. Significant correlations were obtained in log P, log DL(-2), and log KL values between the silicone membrane and human skin. DL(-2) values of model compounds, except flurbiprofen, in the silicone membrane were independent of the lipophilicity of the model compounds and were 100-fold higher than those in human skin. For antipyrine and caffeine, which are hydrophilic, KL values in the silicone membrane were 100-fold lower than those in human skin, and P values, calculated as the product of a DL(-2) and KL, were similar. For lipophilic compounds, such as n-butyl paraben and flurbiprofen, KL values for silicone were similar to or 10-fold higher than those in human skin, and P values for silicone were 100-fold higher than those in human skin. Furthermore, for amphiphilic compounds with log Ko/w values from 0.5 to 3.5, KL values in the silicone membrane were 10-fold lower than those in human skin, and P values for silicone were 10-fold higher than those in human skin. The silicone membrane was useful as a human skin alternative in an in vitro skin permeation study. However, depending on the lipophilicity of the model compounds, some parameters may be over- or underestimated. PMID:27581638

  12. Polydopamine-coated magnetic nanoparticles for isolation and enrichment of estrogenic compounds from surface water samples followed by liquid chromatography-tandem mass spectrometry determination.

    PubMed

    Capriotti, Anna Laura; Cavaliere, Chiara; La Barbera, Giorgia; Piovesana, Susy; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2016-06-01

    Estrogens, phytoestrogens, and mycoestrogens may enter into the surface waters from different sources, such as effluents of municipal wastewater treatment plants, industrial plants, and animal farms and runoff from agricultural areas. In this work, a multiresidue analytical method for the determination of 17 natural estrogenic compounds, including four steroid estrogens, six mycoestrogens, and seven phytoestrogens, in river water samples has been developed. (Fe3O4)-based magnetic nanoparticles coated by polydopamine (Fe3O4@pDA) were used for dispersive solid-phase extraction, and the final extract was analyzed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry. The Fe3O4 magnetic nanoparticles were prepared by a co-precipitation procedure, coated by pDA, and characterized by scanning electron microscopy, infrared spectroscopy, and elemental analysis. The sample preparation method was optimized in terms of extraction recovery, matrix effect, selectivity, trueness, precision, method limits of detection, and method limits of quantification (MLOQs). For all the 17 analytes, recoveries were >70 % and matrix effects were below 30 % when 25 mL of river water sample was treated with 90 mg of Fe3O4@pDA nanoparticles. Selectivity was tested by spiking river water samples with 50 other compounds (mycotoxins, antibacterials, conjugated hormones, UV filters, alkylphenols, etc.), and only aflatoxins and some benzophenones showed recoveries >60 %. This method proved to be simple and robust and allowed the determination of natural estrogenic compounds belonging to different classes in surface waters with MLOQs ranging between 0.003 and 0.1 μg L(-1). Graphical Abstract Determination of natural estrogenic compounds in water by magnetic solid phase extraction followed by liquid chromatography-tandem mass spectrometry analysis.

  13. Polydopamine-coated magnetic nanoparticles for isolation and enrichment of estrogenic compounds from surface water samples followed by liquid chromatography-tandem mass spectrometry determination.

    PubMed

    Capriotti, Anna Laura; Cavaliere, Chiara; La Barbera, Giorgia; Piovesana, Susy; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2016-06-01

    Estrogens, phytoestrogens, and mycoestrogens may enter into the surface waters from different sources, such as effluents of municipal wastewater treatment plants, industrial plants, and animal farms and runoff from agricultural areas. In this work, a multiresidue analytical method for the determination of 17 natural estrogenic compounds, including four steroid estrogens, six mycoestrogens, and seven phytoestrogens, in river water samples has been developed. (Fe3O4)-based magnetic nanoparticles coated by polydopamine (Fe3O4@pDA) were used for dispersive solid-phase extraction, and the final extract was analyzed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry. The Fe3O4 magnetic nanoparticles were prepared by a co-precipitation procedure, coated by pDA, and characterized by scanning electron microscopy, infrared spectroscopy, and elemental analysis. The sample preparation method was optimized in terms of extraction recovery, matrix effect, selectivity, trueness, precision, method limits of detection, and method limits of quantification (MLOQs). For all the 17 analytes, recoveries were >70 % and matrix effects were below 30 % when 25 mL of river water sample was treated with 90 mg of Fe3O4@pDA nanoparticles. Selectivity was tested by spiking river water samples with 50 other compounds (mycotoxins, antibacterials, conjugated hormones, UV filters, alkylphenols, etc.), and only aflatoxins and some benzophenones showed recoveries >60 %. This method proved to be simple and robust and allowed the determination of natural estrogenic compounds belonging to different classes in surface waters with MLOQs ranging between 0.003 and 0.1 μg L(-1). Graphical Abstract Determination of natural estrogenic compounds in water by magnetic solid phase extraction followed by liquid chromatography-tandem mass spectrometry analysis. PMID:27032407

  14. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum

    PubMed Central

    Giorgio, Annalisa; De Stradis, Angelo; Lo Cantore, Pietro; Iacobellis, Nicola S.

    2015-01-01

    Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight (CBB) causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia. Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs). Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria, and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by hemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well. PMID:26500617

  15. Effects of polar and nonpolar groups on the solubility of organic compounds in soil organic matter

    USGS Publications Warehouse

    Chiou, C.T.; Kile, D.E.

    1994-01-01

    Vapor sorption capacities on a high-organic-content peat, a model for soil organic matter (SOM), were determined at room temperature for the following liquids: n-hexane, 1,4-dioxane, nitroethane, acetone, acetonitrile, 1-propanol, ethanol, and methanol. The linear organic vapor sorption is in keeping with the dominance of vapor partition in peat SOM. These data and similar results of carbon tetrachloride (CT), trichloroethylene (TCE), benzene, ethylene glycol monoethyl ether (EGME), and water on the same peat from earlier studies are used to evaluate the effect of polarity on the vapor partition in SOM. The extrapolated liquid solubility from the vapor isotherm increases sharply from 3-6 wt % for low-polarity liquids (hexane, CT, and benzene) to 62 wt % for polar methanol and correlates positively with the liquid's component solubility parameters for polar interaction (??P) and hydrogen bonding (??h). The same polarity effect may be expected to influence the relative solubilities of a variety of contaminants in SOM and, therefore, the relative deviations between the SOM-water partition coefficients (Kom) and corresponding octanol-water partition coefficients (Kow) for different classes of compounds. The large solubility disparity in SOM between polar and nonpolar solutes suggests that the accurate prediction of Kom from Kow or Sw (solute water solubility) would be limited to compounds of similar polarity.

  16. CALUX bioassay: a cost-effective rapid screening technique for screening dioxins like compounds.

    PubMed

    Sakthivel, Selvaraj; Balasubramanian, Prithiviraj; Nakamura, Masafumi; Ko, Shunkei; Chakraborty, Paromita

    2016-03-01

    Xenobiotic detection systems-chemically activated luciferase expression (XDS-CALUX) bioassay in determining the toxic equivalency (TEQ) of PCDD/Fs from contaminated sites reported in several papers has been discussed in this study. CALUX bioassay method has been validated by an effective combined column clean-up system followed by addition of samples to monolayer cell cultures of H1L6.1c3 cell line in 96 well plates. Cultures are then examined under microscope after 24 h incubation followed by rinsing with 75 μL phosphate buffer saline and 30 μL of cell culture lysis. The response is observed in the luminometer and expressed in relative light unit (RLUs). CALUX-TEQ is estimated from a TCDD standard curve for unknown samples. Quality control in CALUX is done by selecting the range of CALUX values falling in the center of the linear standard curve. For developing nations CALUX biossay can be used as a cost effective and rapid screening technique for screening xenobiotic compounds from the hotspots like open solid waste burning sites, informal e-waste recycling workshops and industrial zones where constant monitoring for such compounds is required. PMID:26943601

  17. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum.

    PubMed

    Giorgio, Annalisa; De Stradis, Angelo; Lo Cantore, Pietro; Iacobellis, Nicola S

    2015-01-01

    Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight (CBB) causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia. Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs). Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria, and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by hemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well. PMID:26500617

  18. Simultaneous determination of ten taste and odor compounds in drinking water by solid-phase microextraction combined with gas chromatography-mass spectrometry.

    PubMed

    Chen, Xichao; Luo, Qian; Yuan, Shengguang; Wei, Zi; Song, Hanwen; Wang, Donghong; Wang, Zijian

    2013-11-01

    Taste and odor (T&O) problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol (geosmin) and 2-methylisoborneol (MIB) are well-known. In this study, a fast and effective method was established for simultaneous determination of 10 T&O compounds, including geosmin, MIB, 2,4,6-trichloroanisole (TCA), 2-methylbenzofuran, 2-isopropyl-3-methoxypyrazine (IPMP), 2-isobutyl-3-methoxypyrazine (IBMP), cis-3-hexenyl acetate, trans,trans-2,4-heptadienal, trans, cis-2,6-nonadienal, and trans-2-decenal in water samples by headspace solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry. An orthogonal array experimental design was used to optimize the effects of SPME fiber, extraction temperature, stirring rate, NaCI content, extraction time, and desorption time. The limits of detection ranged from 0.1 to 73 ng/L were lower than or close to the odor threshold concentrations (OTCs). All the 10 T&O compounds were detected in the 14 water samples including surface water, treatment process water and tap water, taken from a waterworks in Lianyungang City, China. MB and geosmin were detected in most samples at low concentration. Six T&O compounds (IPMP, IBMP, trans,cis-2,6-nonadienal, 2-methylbenzofuran, trans-2-decenal, and TCA) were effectively decreased in water treatment process (sedimentation and filtration) that is different from cis-3-hexenyl acetate, MIB and geosmin. It is noted that the TCA concentrations at 15.9-122.3 ng/L and the trans,cis-2,6-nonadienal concentrations at 79.9-190.1 ng/L were over 10 times higher than their OTCs in tap water. The variation of the analytes in the all water samples, especially distribution system indicated that distribution system cannot be ignored as a T&O compounds source.

  19. Kola acuminata proanthocyanidins: a class of anti-trypanosomal compounds effective against Trypanosoma brucei.

    PubMed

    Kubata, B K; Nagamune, Kisaburo; Murakami, Nobutoshi; Merkel, Patrick; Kabututu, Zakayi; Martin, Samuel K; Kalulu, Taba M; Huq, Mostaqul; Mustakuk, Haq; Yoshida, Mitsuru; Ohnishi-Kameyama, Mayumi; Kinoshita, Taroh; Duszenko, Michael; Urade, Yoshihiro

    2005-01-01

    Human African trypanosomiasis is undergoing an alarming rate of recrudescence in many parts of sub-Saharan Africa. Yet, there is no successful chemotherapy for the disease due to a limited number of useful drugs, side effects and drawbacks of the existing medication, as well as the development of drug resistance by the parasite. Here we describe a new lead anti-trypanosomal compound isolated from Kola acuminata (Makasu). We purified a proanthocyanidin by chromatographic procedures and confirmed its homogeneity and structure by Nuclear Magnetic Resonance and Matrix-Assisted Laser Desorption Ionisation Time-of-Flight mass spectrometry, respectively. In vitro, this compound potently induced growth arrest and lysis of bloodstream form trypanosomes in a dose- and time-dependent manner. In a mouse model, it exhibited a trypanostatic effect that extended the life of infected, treated animals up to 8 days post-infection against the 4 days for infected, untreated animals. The proanthocyanidin showed a low cytotoxicity against mammalian cells, whereas treated-BF showed massive enlargement of their flagellar pocket and lysosome-like structures caused by an intense formation of multivesicular bodies and vesicles within these organelles. The observed ultrastructural alterations caused rupture of plasma membranes and the release of cell contents, indicative of a necrotic process rather than a programmed cell death. Interestingly, the proanthocyanidin acted against BF but not procyclic form trypanosomes. This new anti-trypanosomal compound should be further studied to determine its efficacy and suitability as an anti-trypanosomal drug and may be used as a tool to define novel specific drug targets in BF trypanosomes. PMID:15619520

  20. Effects of acid rain on soil humic compounds.

    PubMed

    Calace, N; Fiorentini, F; Petronio, B M; Pietroletti, M

    2001-06-21

    The modifications induced by acid rain on the solubility, molecular configuration and molecular weight distribution of humic (HA) and fulvic (FA) acids were studied. A natural soil was subjected to simulated acid rain until a soil pH of 4 was obtained; HA and FA acids were then extracted and characterised. The results obtained were compared both with those of natural soil and with those of a soil subjected to acid rain. Elute analysis indicates the continuous release of soluble organic compounds as a consequence of acid rain simulation, although no relationship was found with the process of soil acidification. The yields of HA and FA show that HA values are the same while FA amount is higher in the natural soil; in acid soils their water solubility increases. The molecular weight distribution shows that HA consist of a mixture of compounds of different molecular weights; they are molecules for the most part larger than 100 kDa and their distribution is not changed by soil acidification. FA can be considered to form a much more homogeneous system; in natural soil, the molecules are larger than 50 kDa, while in acidified soil they are for the most part smaller than 3 kDa.

  1. Effects of acid rain on soil humic compounds.

    PubMed

    Calace, N; Fiorentini, F; Petronio, B M; Pietroletti, M

    2001-06-21

    The modifications induced by acid rain on the solubility, molecular configuration and molecular weight distribution of humic (HA) and fulvic (FA) acids were studied. A natural soil was subjected to simulated acid rain until a soil pH of 4 was obtained; HA and FA acids were then extracted and characterised. The results obtained were compared both with those of natural soil and with those of a soil subjected to acid rain. Elute analysis indicates the continuous release of soluble organic compounds as a consequence of acid rain simulation, although no relationship was found with the process of soil acidification. The yields of HA and FA show that HA values are the same while FA amount is higher in the natural soil; in acid soils their water solubility increases. The molecular weight distribution shows that HA consist of a mixture of compounds of different molecular weights; they are molecules for the most part larger than 100 kDa and their distribution is not changed by soil acidification. FA can be considered to form a much more homogeneous system; in natural soil, the molecules are larger than 50 kDa, while in acidified soil they are for the most part smaller than 3 kDa. PMID:18968306

  2. Gondola-shaped tetra-rhenium metallacycles modified evanescent wave infrared chemical sensors for selective determination of volatile organic compounds.

    PubMed

    Huang, Genin Gary; Lee, Chung-Jay; Tsai, Bo-Chan; Yang, Jyisy; Sathiyendiran, Malaichamy; Lu, Kuang-Lieh

    2011-07-15

    Water-stable and cavity-contained rhenium metallacycles were synthesized, and their ability to selectively interact with volatile organic compounds (VOCs) systematically studied using attenuated total reflection infrared (ATR-IR) spectroscopy. Integrating the unique properties of rhenium metallacycles into optical sensing technologies significantly improves selectivity in detecting aromatic compounds. To explore the interaction of rhenium metallacycles with VOCs, the surface of ATR sensing elements was modified with the synthesized rhenium metallacycles and used to detect VOCs. The results indicate that rhenium metallacycles have crown ether-like recognition sites, which can selectively interact with aromatic compounds, especially those bearing polar functional groups. The IR absorption bands of rhenium metallacycles shift significantly upon adsorption of aromatic VOCs, revealing a strong interaction between the tetra-rhenium metallacycles and guest aromatic compounds. Optimizing the thickness of the metallacycles coated on the surface of the sensing element led to rapid response in detection. The dynamic range of response was generally up to 30 mg/L with detection limits ca. 30 μg/L. Further studies of the effect of interferences indicate that recovery can be higher than 95% for most of the compounds tested. The results on the flow-cell device indicated that the performances were similar to a static detection system but the detection of VOCs can be largely simplified.

  3. Silver nanoparticle-modified electrode for the determination of nitro compound-containing pesticides.

    PubMed

    de Lima, Camila Alves; Santana, Edson Roberto; Piovesan, Jamille Valéria; Spinelli, Almir

    2016-04-01

    This paper reports the electroanalytical determination of pendimethalin and ethyl parathion by square-wave adsorptive stripping voltammetry using a material comprised of chitosan-stabilized silver nanoparticles to modify a glassy carbon electrode. Under optimized experimental conditions, the peak current was found to vary linearly with the concentration of pendimethalin in the range of 70 to 2000 nmol L(-1) and with concentration of ethyl parathion in the range of 40 to 8000 nmol L(-1). Detection limits of 36 and 40 nmol L(-1) were obtained for pendimethalin and ethyl parathion, respectively. The silver - nanoparticle-modified electrode was successfully employed for the analysis of pesticides in tap and mineral water (pendimethalin) and in lettuce and honey (ethyl parathion) samples. Pendimethalin recovery was between 94 and 100 %, and ethyl parathion recovery was between 97 and 101 %, indicating no significant matrix interference effects on the analytical results. The accuracy of the electroanalytical methodology using the proposed modified electrode was also compared to that of the UV-vis spectrophotometric method. PMID:26873207

  4. [Determination of target compounds in cefoperazone sodium and tazobactam sodium for injection by capillary electrophoresis].

    PubMed

    Jiang, Ruiyuan; Sun, Guoxiang

    2012-01-01

    A capillary zone electrophoresis (CZE) method was developed for the simultaneous determination of cefoperazone sodium and tazobactam sodium in the injectable powder of cefoperazone sodium and tazobactam sodium with hydrochlorothiazide as the internal standard. The operation was carried out on a quartz capillary (75 cm x 75 microm i. d. , 63 cm effective length). The electrophoretic conditions were as follows: 40 mmol/L borax solution as the back ground electrolyte (BGE), 12. 0 kV applied voltage, 220 nm as the detection wavelength; the sample solution was injected by hydraulic pressure for 10 s at the height of 10 cm. The cefoperazone and tazobactam showed good linear relationship in the ranges of 0.25-3.96 g/L and 0.062-0.99 g/L with the correlation coefficients of 0.999 5 and 0.999 6, respectively. The relative standard deviations of relative peak areas were less than 3%. The preparation was stable in 208 min. The recovery results met the methodology requirements. The method is simple, rapid, reproducible, and suitable to control the quality of cefoperazone sodium and tazobactam sodium injectable powder. PMID:22667102

  5. How the Parts Relate to the Whole: Frequency Effects on Children's Interpretations of Novel Compounds

    ERIC Educational Resources Information Center

    Krott, Andrea; Gagne, Christina L.; Nicoladis, Elena

    2009-01-01

    This study explores different frequency effects on children's interpretations of novel noun-noun compounds (e.g. "egg bag" as "bag FOR eggs"). We investigated whether four- to five-year-olds and adults use their knowledge of related compounds and their modifier-head relations (e.g. "sandwich bag (FOR)" or "egg white (PART-OF)") when explaining the…

  6. Effects of furan derivatives and phenolic compounds on electricity generation in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Catal, Tunc; Fan, Yanzhen; Li, Kaichang; Bermek, Hakan; Liu, Hong

    Lignocellulosic biomass is an attractive fuel source for MFCs due to its renewable nature and ready availability. Furan derivatives and phenolic compounds could be potentially formed during the pre-treatment process of lignocellulosic biomass. In this study, voltage generation from these compounds and the effects of these compounds on voltage generation from glucose in air-cathode microbial fuel cells (MFCs) were examined. Except for 5-hydroxymethyl furfural (5-HMF), all the other compounds tested were unable to be utilized directly for electricity production in MFCs in the absence of other electron donors. One furan derivate, 5-HMF and two phenolic compounds, trans-cinnamic acid and 3,5-dimethoxy-4-hydroxy-cinnamic acid did not affect electricity generation from glucose at a concentration up to 10 mM. Four phenolic compounds, including syringaldeyhde, vanillin, trans-4-hydroxy-3-methoxy, and 4-hydroxy cinnamic acids inhibited electricity generation at concentrations above 5 mM. Other compounds, including 2-furaldehyde, benzyl alcohol and acetophenone, inhibited the electricity generation even at concentrations less than 0.2 mM. This study suggests that effective electricity generation from the hydrolysates of lignocellulosic biomass in MFCs may require the employment of the hydrolysis methods with low furan derivatives and phenolic compounds production, or the removal of some strong inhibitors prior to the MFC operation, or the improvement of bacterial tolerance against these compounds through the enrichment of new bacterial cultures or genetic modification of the bacterial strains.

  7. Effects of ATRA combined with citrus and ginger-derived compounds in human SCC xenografts

    PubMed Central

    2010-01-01

    Background NF-κB is a survival signaling transcription factor complex involved in the malignant phenotype of many cancers, including squamous cell carcinomas (SCC). The citrus coumarin, auraptene (AUR), and the ethno-medicinal ginger (Alpinia galanga) phenylpropanoid, 1'-acetoxychavicol acetate (ACA), were previously shown to suppress 12-O-tetradecanoylphorbol-13-acetate (TPA) induced mouse skin tumor promotion. The goal of the present study was to determine whether AUR and ACA are effective either alone or in combination with all-trans retinoic acid (ATRA) for suppressing SCC tumor growth. Methods We first determined the effects of orally administered ACA (100 mg/kg bw) and AUR (200 mg/kg bw) on lipopolysaccharide (LPS)-induced NF-κB activation in NF-κB-RE-luc (Oslo) luciferase reporter mice. Dietary administration of AUR and ACA ± ATRA was next evaluated in a xenograft mouse model. Female SCID/bg mice were fed diets containing the experimental compounds, injected with 1 × 106 SRB12-p9 cells s.c., palpated and weighed twice a week for 28 days following injection. Results Both ACA and AUR suppressed LPS-induced NF-κB activation in the report mice. In the xenograft model, AUR (1000 ppm) and ACA (500 ppm) modestly suppressed tumor volume. However, in combination with ATRA at 5, 10, and 30 ppm, ACA 500 ppm significantly inhibited tumor volume by 56%, 62%, and 98%, respectively. The effect of ATRA alone was 37%, 33%, and 93% inhibition, respectively. AUR 1000 ppm and ATRA 10 ppm were not very effective when administered alone, but when combined, strongly suppressed tumor volume by 84%. Conclusions Citrus AUR may synergize the tumor suppressive effects of ATRA, while ACA may prolong the inhibitory effects of ATRA. Further studies will be necessary to determine whether these combinations may be useful in the control of human SCC. PMID:20659317

  8. Determination of unique microbial volatile organic compounds produced by five Aspergillus species commonly found in problem buildings.

    PubMed

    Gao, Pengfei; Korley, Frederick; Martin, Jennifer; Chen, Bean T

    2002-01-01

    This study identified unique microbial volatile organic compounds (UMVOCs) produced by five Aspergillus species (A. fumigatus, A. versicolor, A. sydowi, A. flavus, and A. niger) cultivated on malt extract agar and gypsum board. The hypothesis was that UMVOCs can be used to predict the presence of Aspergillus species. During the cultivation humidified air was continually supplied and evenly distributed through each of the culture flasks. Volatile metabolites were collected using Tenax TA tubes on Days 8, 16, and 30 after inoculation. The volatile metabolites were determined by gas chromatography/mass spectroscopy after thermal desorption. Nine compounds recognized as UMVOCs--3-methyl-1-butanol; 2-methyl-1-propanol; terpineol; 2-heptanone; 1-octen-3-ol; dimethyl disulfide; 2-hexanone; 3-octanone; and 2-pentylfuran--were found on the cultures in detectable amounts. The first two compounds were detected at the highest frequency when combining both media. The first four compounds were found to be the dominant UMVOCs on gypsum board, which could be used as chemical markers of the common Aspergillus species grown indoors.

  9. Generalized Electron Counting in Determination of Metal-Induced Reconstruction of Compound Semiconductor Surfaces

    SciTech Connect

    Zhang, Lixin; Wang, E. G.; Xue, Qi-Kun; Zhang, S. B.; Zhang, Zhenyu

    2006-01-01

    Based on theoretical analysis, first-principles calculations, and experimental observations, we establish a generic guiding principle, embodied in generalized electron counting (GEC), that governs the surface reconstruction of compound semiconductors induced by different metal adsorbates. Within the GEC model, the adsorbates serve as an electron bath, donating or accepting the right number of electrons as the host surface chooses a specific reconstruction that obeys the classic electron-counting model. The predictive power of the GEC model is illustrated for a wide range of metal adsorbates.

  10. HPLC Determination Of Polycyclic Aromatic Compounds By Fluorescence Detected With A Charge-Coupled Device

    NASA Astrophysics Data System (ADS)

    Jalkian, Rafi D.; Denton, M. Bonner

    1989-05-01

    A solid-state two-dimensional charge-coupled device (CCD) is used to quantitate polycyclic aromatic compounds by native fluorescence. The mixture is separated by reverse phase high performance liquid chromatography (HPLC) and the fluorescence emission from each peak is integrated by the detector. A new technique, charge-dependent variable binning, applied to one-dimensional spectroscopy leads to outstanding dynamic range. Excellent linearity and limits of detection are obtained for several priority pollutants. Synchronous and derivative techniques can be applied to the two-dimensional fluorescence data obtained to resolve overlapping peaks. The analyzed mixture consists of fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, and perylene.

  11. Bioactive compounds of sea cucumbers and their therapeutic effects

    NASA Astrophysics Data System (ADS)

    Shi, Shujuan; Feng, Wenjing; Hu, Song; Liang, Shixiu; An, Nina; Mao, Yongjun

    2016-05-01

    Sea cucumbers belong to the Class Holothuroidea of marine invertebrates. They are commercially valuable and prized as a food and folk medicine in Asia. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as vitamins, minerals and amino acids. A number of unique biological and pharmacological activities/properties, including anticancer, anticoagulant/antithrombotic, antimicrobial, antioxidant, antihyperlipidemic, antihyperglycemic, anti-inflammatory, antihypertension and radioprotective, have been ascribed to various compounds isolated from sea cucumbers. The therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives, especially triterpene glycosides, acid mucopolysaccharide, sphingoid bases, glycolipids, fucosylated chondroitin sulfate, polysaccharides, phospholipids, cerebrosides, phosphatidylcholines, and other extracts and hydrolysates. This review highlights the valuable bioactive components as well as the multiple therapeutic properties of sea cucumbers with a view to exploring their potential uses as functional foods and a natural source of new multifunctional drugs.

  12. Effects of Floodplain Vegetation on Momentum Transfer in Compound Channel

    NASA Astrophysics Data System (ADS)

    Hasegawa, Fumiaki; Yamamoto, Takuya; Jahra, Fatima; Kawahara, Yoshihisa

    Better management of riparian vegetation for flood control and environmental preservation requires in-depth understanding of flow characteristics in the presence of vegetation. This study aims at clarifying the flow structure and lateral momentum transfer process in vegetated compound channels through experiments and numerical simulations. Two types of vegetation zone on a floodplain are discussed. In the first case a floodplain is fully covered by vegetation. In the other case a floodplain has a belt of vegetation zone along the interface between main channel and floodplain. The measured data are compared with the numerical results that are obtained using a non-linear k-ɛ model and a vegetation model. It is found that the numerical model can reproduce the main characteristics of the flow and that the convection and the turbulent diffusion play important roles in the lateral momentum transfer across the interface between vegetated floodplain and main channel.

  13. Effect of applied mechanical stress on absorption coefficient of compounds

    SciTech Connect

    Gupta, Manoj Kumar; Singh, Gurinderjeet; Dhaliwal, A. S.; Kahlon, K. S.

    2015-08-28

    The absorption coefficient of given materials is the parameter required for the basic information. The measurement of absorption coefficient of compounds Al{sub 2}O{sub 3}, CaCO{sub 3}, ZnO{sub 2}, SmO{sub 2} and PbO has been taken at different incident photon energies 26, 59.54, 112, 1173, 1332keV. The studies involve the measurements of absorption coefficient of the self supporting samples prepared under different mechanical stress. This mechanical stress is render in terms of pressure up to 0-6 ton by using hydraulic press. Measurements shows that absorption coefficient of a material is directly proportional to applied mechanical stress on it up to some extent then become independent. Experimentally measured results are in fairly good agreement with in theoretical values obtained from WinXCOM.

  14. Experimentally determined blood and water flow limitations for hydrophobic compounds using perfused gills of trout

    SciTech Connect

    Sijm, D.T.H.M.; Verberne, M.E.; Paert, P.; Opperhuizen, A.

    1995-12-31

    The influence of physiologically relevant water and blood flows on the uptake of a number of hydrophobic compounds was investigated using perfused gills of rainbow trout. For all compounds studied, the uptake rate constants increased with water flow at lower flow and remained constant at higher flow. The uptake rate constants did not change when blood flow decreased at lower flow, while they increased at higher flow. Both water and blood flows thus influence the uptake of hydrophobic chemicals. using these experimental data and allometric relations, it was established that the water flow can limit the uptake of hydrophobic chemicals for fish weighing more than 5 g. The flow of water will not limit uptake in fish < 5 g, irrespective of physiological conditions and oxygen concentration. At low oxygen concentration, which will increase the water flow in large fish, the uptake of hydrophobic chemicals may increase with a factor of 5 or more. Increasing the blood flow may maximally increase the uptake of hydrophobic chemicals two-fold, in small as well as in large fish.

  15. Determination of tobacco smoking influence on volatile organic compounds constituent by indoor tobacco smoking simulation experiment

    NASA Astrophysics Data System (ADS)

    Xie, Juexin; Wang, Xingming; Sheng, Guoying; Bi, Xinhui; Fu, Jiamo

    Tobacco smoking simulation experiment was conducted in a test room under different conditions such as cigarette brands, smoking number, and post-smoke decay in forced ventilation or in closed indoor environments. Thirty-seven chemical species were targeted and monitored, including volatile organic compounds (VOCs) and environmental tobacco smoke (ETS) markers. The results indicate that benzene, d-limonene, styrene, m-ethyltoluene and 1,2,4/1,3,5-trimethylbenzene are correlated well with ETS markers, but toluene, xylene, and ethylbenzene are not evidently correlated with ETS markers because there are some potential indoor sources of these compounds. 2,5-dimethylfuran is considered to be a better ETS marker due to the relative stability in different cigarette brands and a good relationship with other ETS markers. The VOCs concentrations emitted by tobacco smoking were linearly associated with the number of cigarettes consumed, and different behaviors were observed in closed indoor environment, of which ETS markers, d-limonene, styrene, trimethylbenzene, etc. decayed fast, whereas benzene, toluene, xylene, ethylbenzene, etc. decayed slowly and even increased in primary periods of the decay; hence ETS exposure in closed environments is believed to be more dangerous. VOCs concentrations and the relative percentage constituent of ETS markers of different brand cigarettes emissions vary largely, but the relative percentage constituent of ETS markers for the same brand cigarette emissions is similar.

  16. Emissions of halogenated compounds in East Asia determined from measurements at Jeju Island, Korea.

    PubMed

    Li, Shanlan; Kim, Jooil; Kim, Kyung-Ryul; Mühle, Jens; Kim, Seung-Kyu; Park, Mi-Kyung; Stohl, Andreas; Kang, Dong-Jin; Arnold, Tim; Harth, Christina M; Salameh, Peter K; Weiss, Ray F

    2011-07-01

    High-frequency in situ measurements at Gosan (Jeju Island, Korea) during November 2007 to December 2008 have been combined with interspecies correlation analysis to estimate national emissions of halogenated compounds (HCs) in East Asia, including the chlorofluorocarbons (CFCs), halons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF(6)), and other chlorinated and brominated compounds. Our results suggest that overall China is the dominant emitter of HCs in East Asia, however significant emissions are also found in South Korea, Japan and Taiwan for HFC-134a, HFC-143a, C(2)F(6), SF(6), CH(3)CCl(3), and HFC-365mfc. The combined emissions of CFCs, halon-1211, HCFCs, HFCs, PFCs, and SF(6) from all four countries in 2008 are 25.3, 1.6, 135, 42.6, 3.6, and 2.0 kt/a, respectively. They account for approximately 15%, 26%, 29%, 16%, 32%, and 26.5% of global emissions, respectively. Our results show signs that Japan has successfully phased out CFCs and HCFCs in compliance with the Montreal Protocol (MP), Korea has started transitioning from HCFCs to HFCs, while China still significantly consumes HCFCs. Taiwan, while not directly regulated under the MP, is shown to have adapted the use of HFCs. Combined analysis of emission rates and the interspecies correlation matrix presented in this study proves to be a powerful tool for monitoring and diagnosing changes in consumption of HCs in East Asia. PMID:21649439

  17. Different formats of imprinted polymers for determining organotin compounds in environmental samples.

    PubMed

    Gallego-Gallegos, Mercedes; Muñoz-Olivas, Riansares; Cámara, Carmen

    2009-02-01

    Organotin compounds and their degradation products enter the environment mainly as a result of their use as biocides and antifouling paints. Analysis of these compounds in environmental samples has to be very sensitive and selective so that their concentrations corresponding to the low environmental target values can also be detected. Generally, analysis of a complex matrix leads to high interferences during the different process steps; clean-up procedures are recommended to overcome this problem. For the past many years, solid phase extraction by employing imprinted materials has been extensively used for many organic substances that are used for pre-concentration and clean-up purposes with excellent results. Here, we present three different imprinted polymers prepared via bulk, precipitation, and emulsion polymerization methods that use similar compositions. The synthesized polymer particles were characterized morphologically by employing scanning electron microscopy and Brunauer-Emmett-Teller analysis. Binding properties were calculated using the Langmuir-Freundlich isotherm. Depending on the properties of the materials, different analytical applications for complex matrices are proposed. These applications are mainly used on tributyltin and its degradation products for environmental analysis.

  18. Heats of formation of phosphorus compounds determined by current methods of computational quantum chemistry

    NASA Astrophysics Data System (ADS)

    Haworth, Naomi L.; Bacskay, George B.

    2002-12-01

    The heats of formation of a range of phosphorus containing molecules (P2, P4, PH, PH2, PH3, P2H2, P2H4, PO, PO2, PO3, P2O, P2O2, HPO, HPOH, H2POH, H3PO, HOPO, and HOPO2) have been determined by high level quantum chemical calculations. The equilibrium geometries and vibrational frequencies were computed via density functional theory, utilizing the B3LYP/6-31G(2df,p) functional and basis set. Atomization energies were obtained by the application of ab initio coupled cluster theory with single and double excitations from (spin)-restricted Hartree-Fock reference states with perturbative correction for triples [CCSD(T)], in conjunction with cc-pVnZ basis sets (n=T, Q, 5) which include an extra d function on the phosphorus atoms and diffuse functions on the oxygens, as recommended by Bauschlicher [J. Phys. Chem. A 103, 11126 (1999)]. The valence correlated atomization energies were extrapolated to the complete basis limit and corrected for core-valence (CV) correlation and scalar relativistic effects, as well as for basis set superposition errors (BSSE) in the CV terms. This methodology is effectively the same as the one adopted by Bauschlicher in his study of PO, PO2, PO3, HPO, HOPO, and HOPO2. Consequently, for these molecules the results of this work closely match Bauschlicher's computed values. The theoretical heats of formation, whose accuracy is estimated as ranging from ±1.0 to ±2.5 kcal mol-1, are consistent with the available experimental data. The current set of theoretical data represent a convenient benchmark, against which the results of other computational procedures, such as G3, G3X, and G3X2, can be compared. Despite the fact that G3X2 [which is an approximation to the quadratic CI procedure QCISD(T,Full)/G3Xlarge] is a formally higher level theory than G3X, the heats of formation obtained by these two methods are found to be of comparable accuracy. Both reproduce the benchmark heats of formation on the average to within ±2 kcal mol-1 and, for these

  19. Recovery of several volatile organic compounds from simulated water samples: Effect of transport and storage

    USGS Publications Warehouse

    Friedman, L.C.; Schroder, L.J.; Brooks, M.G.

    1986-01-01

    Solutions containing volatile organic compounds were prepared in organic-free water and 2% methanol and submitted to two U.S. Geological Survey laboratories. Data from the determination of volatile compounds in these samples were compared to analytical data for the same volatile compounds that had been kept in solutions 100 times more concentrated until immediately before analysis; there was no statistically significant difference in the analytical recoveries. Addition of 2% methanol to the storage containers hindered the recovery of bromomethane and vinyl chloride. Methanol addition did not enhance sample stability. Further, there was no statistically significant difference in results from the two laboratories, and the recovery efficiency was more than 80% in more than half of the determinations made. In a subsequent study, six of eight volatile compounds showed no significant loss of recovery after 34 days.

  20. Effect of Sex on Flavor-related and Functional Compounds in Freeze-dried Broth Made from Korean Native Chicken

    PubMed Central

    Jayasena, Dinesh D.; Jung, Samooel; Alahakoon, Amali U.; Nam, Ki Chang

    2014-01-01

    Studies on the flavour characteristics of meat-based broth, quantification of flavour-related and functional compounds, and factors affecting the availability of such compounds are minimal. The present study was designed to determine the effects of sex on flavor-related and functional compounds in freeze-dried broth (FDB) made from Korean native chickens (KNC). Male and female KNC from a commercial strain (WoorimatdagTM) were reared under similar commercial conditions. FDB was separately prepared using male and female birds aged 100 d (six birds of each sex) and analyzed for nucleotide, free amino acid, betaine, carnitine, carnosine, anserine, and creatine contents, and fatty acid composition. The levels of betaine, carnitine and creatine in FDB were not significantly different between the two sexes (p>0.05) in KNC. Carnosine and anserine were not detected in FDB samples. However, FDB from female chickens had significantly higher inosine-5-monophosphate and arachidonic acid contents than did FDB from male chickens. FDB prepared with male KNC contained higher levels of inosine, linoleic acid, glycine, alanine, lysine, and serine (p<0.05). However, glutamic acid, oleic acid, and DHA were present in comparable amounts (p>0.05) in FDB made from male and female KNC. Our findings suggest that the sex of KNC has significant effect on the contents of flavor-related compounds, but not functional compounds. PMID:26761282

  1. Cryogenic magneto-caloric effect and magneto-structural correlations in carboxylate-bridged Gd(III) compounds.

    PubMed

    Roubeau, O; Lorusso, G; Teat, S J; Evangelisti, M

    2014-08-14

    Two new infinite coordination chain compounds [Gd(CH3CO2)3(dmf)]∞ (1) and {[Gd(HO(CH2)3CO2)3(H2O)]·H2O}∞ (2) have been obtained attempting to modify a prototype molecular cooler. The structures of both compounds as determined by single-crystal X-ray diffraction are reported, together with a detailed study of their magnetic and thermal properties, describing for both compounds a large magneto-caloric effect. The dominant ferromagnetic interaction present in 2 clearly favours this material at low applied magnetic fields, with respect to 1 that exhibits antiferromagnetic interactions. Magneto-structural correlations of the sign and strength of the magnetic interactions are derived for carboxylato-bridged Gd(III) systems.

  2. Focused ultrasound solid-liquid extraction for the determination of perfluorinated compounds in fish, vegetables and amended soil.

    PubMed

    Zabaleta, Itsaso; Bizkarguenaga, Ekhiñe; Iparragirre, Arantza; Navarro, Patricia; Prieto, Ailette; Fernández, Luis Ángel; Zuloaga, Olatz

    2014-02-28

    In the present work a method was developed for the determination of different perfluorinated compounds (PFCs), including three perfluorinated sulfonic acids (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) in fish, vegetables and amended soil samples based on focused ultrasound solid-liquid extraction (FUSLE) followed by solid-phase extraction (SPE) clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Different variables affecting the chromatographic separation (column type and pH of the mobile phase), the electrospray ionization (capillary voltage, nebulizer pressure and drying gas flow) and mass spectrometric detection (fragmentor voltage and collision energy) were optimized in order to improve the sensitivity of the separation and detection steps. In the case of FUSLE variables such as the solvent type, the solvent volume, the extraction temperature, the sonication and extraction time and the percentage of applied irradiation power were studied. Under optimized conditions, sonication of 2.5min with pulse times on of 0.8s and pulse times off of 0.2s in 7mL of (9:1) acetonitrile (ACN): water mixture in duplicate guaranteed exhaustive extraction of the matrices analyzed. Due to the non-selective extraction using FUSLE, different SPE cartridges (200-mg Waters Oasis-HLB, 150-mg Waters Oasis-WAX and 150-mg Waters Oasis-MAX) were tested in terms of extraction efficiency and matrix effect both in the extraction and detection steps. Mix mode SPE using Waters Oasis-WAX provided the best extraction efficiencies with the lowest matrix effect. The final method was validated in terms of recovery at two fortification levels (in the 80-120% for most of the analytes and matrices), precision (relative standard deviation in the 2-15% range) and method detection limits (MDLs, 0.3-12.4ng/g for vegetables, 0.2-12.5ng/g for fish and 1-22ng/g for amended soil). Finally the method was

  3. Effect of pulp reduction and pasteurization on the release of aroma compounds in industrial orange juice.

    PubMed

    Berlinet, C; Guichard, E; Fournier, N; Ducruet, V

    2007-10-01

    Release of aroma compounds in orange juice according to pulp content and pasteurization was performed by headspace-solid phase microextraction (HS-SPME), HS-SPME-GC-olfactometry, and by the determination of partition coefficients of aroma compounds between the juice and the headspace. Orange juices with 12% and 6% pulp contents were collected from a processing line before and after pasteurization. HS-SPME revealed that the 6% pulp juice was the most affected by pasteurization, with an increase in the release of several aroma compounds that are generated by heat treatment (that is, alpha- and beta-terpinéol) and a decrease in the release of compounds sensitive to pasteurization (that is, neral and geranial). Principal component analysis of olfactometric data allowed discriminating fresh and pasteurized juices, regardless of the pulp content. The determination of the gas/liquid partition coefficients by the phase ratio variation method was possible for 7 aroma compounds. For the most hydrophobic ones, the release of aroma compounds in fresh juices was higher in the 6% pulp juice than in the 12% pulp juice. However, in pasteurized juices, the difference between their partition coefficients was less marked. Potential interactions between cloud proteins and hydrophobic aroma compounds may explain this phenomenon.

  4. Melanocytotoxicity and antimelanoma effects of phenolic amine compounds in mice in vivo

    SciTech Connect

    Alena, F.; Jimbow, K.; Ito, S. )

    1990-06-15

    A phenolic amine compound, 4-S-cysteaminylphenol (4-S-CAP), is a potent depigmenting agent. To develop more efficacious antimelanoma agents, we synthesized four homologues of 4-S-CAP: N-acetyl-4-S-CAP (N-Ac-4-S-CAP), alpha-methyl-4-S-CAP, 4-S-homo-CAP, and N,N'-dimethyl-4-S-CAP. We tested these five compounds in mice in vivo. After s.c. or i.p. injection of saline solution (in control groups) or one of the compounds, follicular melanocytes were examined by light and electron microscopy to assess the degree of melanocytotoxicity; N-Ac-4-S-CAP induced the most depigmentation (98%), whether given i.p. or s.c. After injection of 4-S-CAP or N-Ac-4-S-CAP, the number of murine B16F10 melanoma colonies formed in the lungs was determined; 4-S-CAP and N-Ac-4-S-CAP were almost equally effective, reducing the colonies to 32 and 25% of mean control, respectively. Metabolic studies of the urine showed 9% of 4-S-CAP and 20% of N-Ac-4-S-CAP injected i.p. were excreted unchanged in 24 h; 1.3% of the N-Ac-4-S-CAP was excreted as 4-S-CAP, indicating some conversion. We conclude that N-Ac-4-S-CAP is a suitable model for developing chemotherapy to treat melanoma characterized by high tyrosinase activity and melanin synthesis.

  5. Effect of wetting and drying on the bioavailability of organic compounds sequestered in soil

    SciTech Connect

    White, J.C.; Quinones-Rivera, A.; Alexander, M.

    1998-12-01

    A study was conducted to determine whether cycles of wetting and drying alter the availability of organic compounds that have aged in soil. Subjecting soil to wetting-and drying cycles during periods of aging <60 d decreased the biodegradability, extractability, and uptake by earthworms of phenanthrene and reduced the extractability of di(2-ethylhexyl) phthalate (DEHP) sequestered in soil compared with soil aged at constant moisture. The mineralization of sequestered DEHP was greater in soil that was wet and dried during a 41-d period of aging than in soil incubated at constant moisture. Wetting and drying soil during periods of aging of 100 or more days had no effect on the biodegradability or assimilation by Eisenia foetida of sequestered phenanthrene and DEHP. Subjecting soil containing previously sequestered phenanthrene to one, three, or four wetting-and-drying cycles increased the biodegradability of the compound. The extractability of sequestered phenanthrene was greater in soil that was wet and dried once after aging than in soil maintained at constant moisture, but three wetting-and-drying cycles did not affect extractability. The biodegradability of sequestered DEHP was unaffected by wetting and drying. The authors suggest that wetting and drying may be useful in the remediation of contaminated soils.

  6. A study of effect of the compound physical activity therapy on muscular strength in obese women.

    PubMed

    Kak, Hwang-Bo; Cho, Sung-Hyoun; Lee, Young-Hwa; Cho, Byung-Jun; Kim, Jin-Woo; Oh, Byoung-Don; Koh, Hyung-Woo

    2013-08-01

    [Purpose] The aim of this study was to determine how compound physical activity affects muscular strength of middle-aged obese women. [Subjects] The research subjects were 40-50 year-old middle-aged women with excess body fat (30%). [Methods] The subjects were randomly assigned to two group, the experimental group and the control group. The experimental group performed two types of exercise programs for 16 weeks. Aerobic physical activity was performed 5 times per week, and anaerobic physical activity was performed every two days, and the exercise program each day was composed of a warm-up, the main exercise, and cooldown. The type of exercise focused on walking at a quick pace, and the intensity of the exercise focused on long periods of exercise at low intensity with the level of HRmax being 40-60%. The weight training, which was useful for beginners, as a type of kinetic load exercise, was applied with a composition recommended by the ACSM for muscle fitness (intensity of 40-60% of 1 RM and 10-15 repetitions). SPSS version 16.0 was used to analyze the data by ANCOVA and the t-test. [Results] The chest, leg, and abdominal strengths were significantly increased in the experimental group, and this indicates that compound physical activity is effective for improvement of muscular strength. [Conclusion] In conclusion, there were significant differences between groups in terms of muscular strength.

  7. Determination of volatile organic compounds from biowaste and co-fermentation biogas plants by single-sorbent adsorption.

    PubMed

    Salazar Gómez, J I; Lohmann, H; Krassowski, J

    2016-06-01

    Characterisation of biogases is normally dedicated to the online monitoring of the major components methane and carbon dioxide and, to a lesser extent, to the determination of ammonia and hydrogen sulphide. For the case of Volatile Organic Compounds (VOCs), much less attention is usually paid, since such compounds are normally removed during gas conditioning and with exception of sulphur compounds and siloxanes represent a rather low risk to conventional downstream devices but could be a hindrance for fuel cells. However, there is very little information in the literature about the type of substances found in biogases generated from biowaste or co-fermentation plants and their concentration fluctuations. The main aim of this study was to provide information about the time dependencies of the VOCs in three biogas plants spread out through Germany from autumn until summer, which have different process control, in order to assess their potential as biofuels. Additionally, this study was an attempt to establish a correlation between the nature of the substrates used in the biogas plants and the composition of the VOCs present in the gas phase. Significant time-dependent variations in concentration were observed for most VOCs but only small changes in composition were observed. In general, terpenes and ketones appeared as the predominant VOCs in biogas. Although for substances such as esters, sulphur-organic compounds and siloxanes the average concentrations observed were rather low, they exhibited significant concentration peaks. The second biogas plant which operates with dry fermentation was found to contain the highest levels of VOCs. The amount of total volatile organic compounds (TVOCs) for the first, second and third biogas plants ranged from 35 to 259 mg Nm(-3), 291-1731 mg Nm(-3) and 84-528 mg Nm(-3), respectively. PMID:27010166

  8. Determination of volatile organic compounds from biowaste and co-fermentation biogas plants by single-sorbent adsorption.

    PubMed

    Salazar Gómez, J I; Lohmann, H; Krassowski, J

    2016-06-01

    Characterisation of biogases is normally dedicated to the online monitoring of the major components methane and carbon dioxide and, to a lesser extent, to the determination of ammonia and hydrogen sulphide. For the case of Volatile Organic Compounds (VOCs), much less attention is usually paid, since such compounds are normally removed during gas conditioning and with exception of sulphur compounds and siloxanes represent a rather low risk to conventional downstream devices but could be a hindrance for fuel cells. However, there is very little information in the literature about the type of substances found in biogases generated from biowaste or co-fermentation plants and their concentration fluctuations. The main aim of this study was to provide information about the time dependencies of the VOCs in three biogas plants spread out through Germany from autumn until summer, which have different process control, in order to assess their potential as biofuels. Additionally, this study was an attempt to establish a correlation between the nature of the substrates used in the biogas plants and the composition of the VOCs present in the gas phase. Significant time-dependent variations in concentration were observed for most VOCs but only small changes in composition were observed. In general, terpenes and ketones appeared as the predominant VOCs in biogas. Although for substances such as esters, sulphur-organic compounds and siloxanes the average concentrations observed were rather low, they exhibited significant concentration peaks. The second biogas plant which operates with dry fermentation was found to contain the highest levels of VOCs. The amount of total volatile organic compounds (TVOCs) for the first, second and third biogas plants ranged from 35 to 259 mg Nm(-3), 291-1731 mg Nm(-3) and 84-528 mg Nm(-3), respectively.

  9. Energetic Properties of Rocket Propellants Evaluated through the Computational Determination of Heats of Formation of Nitrogen-Rich Compounds.

    PubMed

    Forquet, Valérian; Miró Sabaté, Carles; Chermette, Henry; Jacob, Guy; Labarthe, Émilie; Delalu, Henri; Darwich, Chaza

    2016-03-01

    The use of ab initio and DFT methods to calculate the enthalpies of formation of solid ionic compounds is described. The results obtained from the calculations are then compared with those from experimental measurements on nitrogen-rich salts of the 2,2-dimethyltriazanium cation (DMTZ) synthesized in our laboratory and on other nitrogen-rich ionic compounds. The importance of calculating accurate volumes and lattice enthalpies for the determination of heats of formation is also discussed. Furthermore, the crystal structure and hydrogen-bonding networks of the nitroformate salt of the DMTZ cation is described in detail. Lastly, the theoretical heats of formation were used to calculate the specific impulses (Isp ) of the salts of the DMTZ cation in view of a prospective application in propellant formulations.

  10. Radial basis function neural networks in non-destructive determination of compound aspirin tablets on NIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Dou, Ying; Mi, Hong; Zhao, Lingzhi; Ren, Yuqiu; Ren, Yulin

    2006-09-01

    The application of the second most popular artificial neural networks (ANNs), namely, the radial basis function (RBF) networks, has been developed for quantitative analysis of drugs during the last decade. In this paper, the two components (aspirin and phenacetin) were simultaneously determined in compound aspirin tablets by using near-infrared (NIR) spectroscopy and RBF networks. The total database was randomly divided into a training set (50) and a testing set (17). Different preprocessing methods (standard normal variate (SNV), multiplicative scatter correction (MSC), first-derivative and second-derivative) were applied to two sets of NIR spectra of compound aspirin tablets with different concentrations of two active components and compared each other. After that, the performance of RBF learning algorithm adopted the nearest neighbor clustering algorithm (NNCA) and the criterion for selection used a cross-validation technique. Results show that using RBF networks to quantificationally analyze tablets is reliable, and the best RBF model was obtained by first-derivative spectra.

  11. Determination of direct photolysis rate constants and OH radical reactivity of representative odour compounds in brewery broth using a continuous flow-stirred photoreactor

    NASA Astrophysics Data System (ADS)

    Jürgens, Marion; Jacob, Fritz; Ekici, Perihan; Friess, Albrecht; Parlar, Harun

    A method based on photolysis was developed for the appropriate treatment of organic pollutants in air exhausting from breweries upon wort decoction, and thereby causing smell nuisance. A continuous flow stirred photoreactor was built-up exclusively, allowing OH radicals to react with selected odorous compounds contained in exhaust vapours, such as: 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, 3-methyl-1-butanol, n-hexanal, 2-methylbutyl isobutyrate, 2-undecanone, phenyl acetaldehyde, myrcene, limonene, linalool, humulene, dimethylsulphide, and dimethyltrisulphide. These substances were quantified in brewery broth before and after UV irradiation using high-resolution gas chromatography-mass spectrometry (HRGC-MS). For odour analysis, high-resolution gas chromatography-flame ionisation detection (HRGC-FID) coupled with sensory methods was used. Determined quantum yields of about 10 -3 for phenyl acetaldehyde, myrcene, and humulene pointed out that direct photolysis contributed to their decay. Quantum yields of below 10 -4 for the other substances indicated that UV irradiation did not contribute significantly to their degradation processes. Hydroxyl radical reaction rate constants and Henry constants of organic compounds were also measured. Substances accompanied with low Henry constants converted rapidly, whereas those with higher ones, relatively slowly. Determined aroma values concluded that after UV-H 2O 2 treatment, only dimethylsulphide and myrcene remained as important odorous compounds, but in significantly reduced concentrations. The UV-H 2O 2 treatment of brewery broth has been proved effective to reduce smell-irritating substances formed upon wort decoction.

  12. Synthesis of α, β-unsaturated carbonyl based compounds as acetylcholinesterase and butyrylcholinesterase inhibitors: characterization, molecular modeling, QSAR studies and effect against amyloid β-induced cytotoxicity.

    PubMed

    Bukhari, Syed Nasir Abbas; Jantan, Ibrahim; Masand, Vijay H; Mahajan, Devidas T; Sher, Muhammad; Naeem-ul-Hassan, M; Amjad, Muhammad Wahab

    2014-08-18

    A series of novel carbonyl compounds was synthesized by a simple, eco-friendly and efficient method. These compounds were screened for anti-oxidant activity, in vitro cytotoxicity and for inhibitory activity for acetylcholinesterase and butyrylcholinesterase. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. Among them, compound 14 exhibited strong free radical scavenging activity (18.39 μM) while six compounds (1, 3, 4, 13, 14, and 19) were found to be the most protective against Aβ-induced neuronal cell death in PC12 cells. Compounds 4 and 14, containing N-methyl-4-piperidone linker, showed high acetylcholinesterase inhibitory activity as compared to reference drug donepezil. Molecular docking and QSAR (Quantitative Structure-Activity Relationship) studies were also carried out to determine the structural features that are responsible for the acetylcholinesterase and butyrylcholinesterase inhibitory activity.

  13. Supercritical carbon dioxide extraction of compounds with antimicrobial activity from Origanum vulgare L.: determination of optimal extraction parameters.

    PubMed

    Santoyo, S; Cavero, S; Jaime, L; Ibañez, E; Señoráns, F J; Reglero, G

    2006-02-01

    Oregano leaves were extracted using a pilot-scale supercritical fluid extraction plant under a wide range of extraction conditions, with the goal of determining the extraction and fractionation conditions to obtain extracts with optimal antimicrobial activity. In this investigation, the essential oil-rich fractions were selectively precipitated in the second separator, and their chemical composition and antimicrobial activity were investigated. Gas chromatography-mass spectrometry analysis of the various fractions resulted in the identification of 27 compounds of the essential oil. The main components of these fractions were carvacrol, trans-sabinene hydrate, cis-piperitol, borneol, terpinen-4-ol, and linalool. Antimicrobial activity was investigated by the disk diffusion and broth dilution methods against six different microbial species, including two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), a yeast (Candida albicans), and a fungus (Aspergillus niger). All of the supercritical fluid extraction fractions obtained showed antimicrobial activity against all of the microorganisms tested, although the most active fraction was the one obtained in experiment 5 (fraction was obtained with 7% ethanol at 150 bar and 40 degrees C). C. albicans was the most sensitive microorganism to the oregano extracts, whereas the least susceptible was A. niger. Carvacrol, sabinene hydrate, borneol, and linalool standards also showed antimicrobial activity against all of the microorganisms tested, with carvacrol being the most effective. Consequently, it was confirmed that essential oil from experiment 5, with the best antimicrobial activity, also presented the highest quantity of carvacrol. PMID:16496578

  14. Compound nucleus formation probability PCN determined within the dynamical cluster-decay model for various "hot" fusion reactions

    NASA Astrophysics Data System (ADS)

    Kaur, Arshdeep; Chopra, Sahila; Gupta, Raj K.

    2014-08-01

    The compound nucleus (CN) fusion/formation probability PCN is defined and its detailed variations with the CN excitation energy E*, center-of-mass energy Ec .m., fissility parameter χ, CN mass number ACN, and Coulomb interaction parameter Z1Z2 are studied for the first time within the dynamical cluster-decay model (DCM). The model is a nonstatistical description of the decay of a CN to all possible processes. The (total) fusion cross section σfusion is the sum of the CN and noncompound nucleus (nCN) decay cross sections, each calculated as the dynamical fragmentation process. The CN cross section σCN is constituted of evaporation residues and fusion-fission, including intermediate-mass fragments, each calculated for all contributing decay fragments (A1, A2) in terms of their formation and barrier penetration probabilities P0 and P. The nCN cross section σnCN is determined as the quasi-fission (qf) process, where P0=1 and P is calculated for the entrance-channel nuclei. The DCM, with effects of deformations and orientations of nuclei included in it, is used to study the PCN for about a dozen "hot" fusion reactions forming a CN of mass number A ˜100 to superheavy nuclei and for various different nuclear interaction potentials. Interesting results are that PCN=1 for complete fusion, but PCN<1 or PCN≪1 due to the nCN contribution, depending strongly on different parameters of the entrance-channel reaction but found to be independent of the nuclear interaction potentials used.

  15. Mycotoxin-contaminated diets and deactivating compound in laying hens: 1. effects on performance characteristics and relative organ weight.

    PubMed

    Lee, J T; Jessen, K A; Beltran, R; Starkl, V; Schatzmayr, G; Borutova, R; Caldwell, D J

    2012-09-01

    The current experiment was conducted to determine the effect of mycotoxin-contaminated diets with aflatoxin (AFLA) and deoxynivalenol (DON) and dietary inclusion of deactivation compound on layer hen performance during a 10-wk trial. The experimental design consisted of a 4 × 2 factorial with 4 toxin levels: control, low (0.5 mg/kg AFLA + 1.0 mg/kg DON), medium (1.5 mg/kg AFLA + 1.5 mg/kg DON), and high (2.0 mg/kg AFLA + 2.0 mg/kg DON) with or without the inclusion of deactivation compound. Three hundred eighty-four 25-wk-old laying hens were randomly assigned to 1 of the 8 treatment groups. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Twelve hens from each treatment were subjected to necropsy following each phase. Relative liver and kidney weights were increased (P < 0.05) at the medium and high toxin levels following the toxin phase, but the deactivation compound reduced (P < 0.05) relative liver and kidney weights following the recovery period. The high toxin level decreased (P < 0.05) feed consumption and egg production during the toxin period, whereas the deactivation compound increased (P < 0.05) egg production during the first 2 wk of the toxin phase. Egg weights were reduced (P < 0.05) in hens fed medium and high levels of toxin. An interaction existed between toxin level and deactivation compound inclusion with regard to feed conversion (g of feed/g of egg). High inclusion level of toxins increased feed conversion compared with the control diet, whereas deactivation compound inclusion reduced feed conversion to a level comparable with the control. These data indicate that deactivation compound can reduce or eliminate adverse effects of mycotoxicoses in peak-performing laying hens.

  16. Determination of the solubility of crystalline low molar mass compounds in polymers by differential scanning calorimetry.

    PubMed

    Rager, Timo

    2014-06-01

    A mathematical equation has been derived to calculate the liquidus for a binary system consisting of an amorphous polymer and a crystalline low molar mass compound. The experimental input to this equation is an interaction enthalpy, which is derived from the variation of the melting enthalpy with composition in differential scanning calorimetry (DSC) experiments. The predictive power of the equation has been tested with mixtures of acetylsalicylic acid, carbamazepine, or intraconazole with poly(ethylene glycol) as well as mixtures of carbamazepine with poly(acrylic acid), poly(hydroxystyrene), or poly(vinylpyrrolidone). It has been confirmed that the evaluation of the melting enthalpy in DSC is a suitable method to identify the preferred solute-polymer combinations for thermodynamically stable molecular dispersions. PMID:24723307

  17. Interlaboratory evaluation of volatile organic compound determinations in soils prepared by vapor fortification

    SciTech Connect

    Hewitt, A.D.; Grant, C.L.

    1995-12-31

    The feasibility of using vapor fortification to prepare secondary soil standards containing volatile organic compounds (VOCs) was evaluated by an interlaboratory study. Twelve laboratories used EPA Method 8240 (SW846) to analyze two independently prepared subsamples of three different soil matrices fortified with trans-1,2-dichloroethylene (TDCE), trichloroethylene (TCE), benzene (Ben), and toluene (Tol). A quality assurance (QA) standard with certified concentrations of TCE, Ben, and Tol (no TDCE) was also analyzed. The pooled relative standard deviation (RSD) for the QA standard was 7.8%, while the same analytes in the soils produced a pooled RSD of 10.4%. Agreement of these precision estimates is excellent, considering that soil analysis required an extraction step while the QA Standard was solvent (methanol) based. TDCE in the soils yielded less precise results (pooled RSD of 20.3%), presumably because of its high volatility.

  18. Determination of the solubility of crystalline low molar mass compounds in polymers by differential scanning calorimetry.

    PubMed

    Rager, Timo

    2014-06-01

    A mathematical equation has been derived to calculate the liquidus for a binary system consisting of an amorphous polymer and a crystalline low molar mass compound. The experimental input to this equation is an interaction enthalpy, which is derived from the variation of the melting enthalpy with composition in differential scanning calorimetry (DSC) experiments. The predictive power of the equation has been tested with mixtures of acetylsalicylic acid, carbamazepine, or intraconazole with poly(ethylene glycol) as well as mixtures of carbamazepine with poly(acrylic acid), poly(hydroxystyrene), or poly(vinylpyrrolidone). It has been confirmed that the evaluation of the melting enthalpy in DSC is a suitable method to identify the preferred solute-polymer combinations for thermodynamically stable molecular dispersions.

  19. Effects of polyhalogenated aromatic compounds on porphyrin metabolism.

    PubMed Central

    Hill, R H

    1985-01-01

    Heme production is a vital metabolic process that occurs in the bone marrow and liver. Porphyrins are unused by-products of this biosynthetic process and normally occur in urine and other body fluids in low concentrations. Various disorders can disrupt the heme biosynthetic process, causing greater quantities of porphyrins in urine. The porphyrias are a group of diseases characterized by excessive porphyrins and other precursors in urine. Porphyrias may be either hereditary or acquired through exposure to certain drugs or chemicals. Porphyria cutanea tarda (PCT) is the disease associated with exposure to polyhalogenated aromatic compounds. The urinary porphyrin pattern is of great value in diagnosing PCT and defining the etiology of the disease. As this liver disease from chemical damage develops, the urinary pattern progressively changes. With the development of a rapid and sensitive high-performance liquid chromatography analysis, urinary porphyrin patterns can be easily monitored. All free porphyrin acids can be quantitatively analyzed in less than 15 min. In our studies of groups exposed to porphyrinogenic chemicals, we have not observed clear differences in the urinary porphyrin patterns of cases when compared with carefully selected controls. In animal studies, however, PCT was clearly associated with polybrominated biphenyl exposure. Future evaluation of the utility of urinary porphyrin patterns as a diagnostic tool will require a cohort that has received a recent, well-documented exposure and a comparable control population. Assay of erythrocyte uroporphyrinogen decarboxylase activity will also be needed to define the form of the PCT. PMID:4029097

  20. Immunomodulatory Effects of Soybeans and Processed Soy Food Compounds.

    PubMed

    Tezuka, Hiroyuki; Imai, Shinjiro

    2015-01-01

    Inflammation is an immune response against both internal and external antigens in organisms, particularly in mammals, and includes both uncontrolled chronic and low-grade inflammations. Uncontrolled chronic inflammation often leads to severe diseases such as vascular disease, arthritis, cancer, diabete, allergy, and autoimmunity. On the other hand, low-grade inflammation is recognized as a relationship between obesity and risk of metabolic syndrome. Elevated production of pro-inflammatory cytokines and mediators is commonly observed in patients with uncontrolled or low-grade inflammation-associated diseases. Plants have been generated phytochemicals to overcome inflammations and infections through evolution. Phytochemicals belong to alkaloids, polyphenols, flavonoids, coumarins, and terpenoids. The consumption of soybeans plays a role in immune modulation through their components such as isoflavones, saponins, and anthocyanins. Recently, it was reported that the application of phytochemicals into patients with inflammatory diseases improves their symptoms. Therefore, it is important to identify novel phytochemicals with immunomodulatory activities. This review introduces and discusses recent advances and patents regarding soybean or processed soy food compounds which exhibit immunomodulatory activity in immune diseases, particularly allergy, by mediating the suppression of inflammatory pathways.

  1. Determination of ten perfluorinated compounds in bluegill sunfish (Lepomis macrochirus) fillets

    SciTech Connect

    Delinsky, Amy D.; Strynar, Mark J.; Nakayama, Shoji F.; Varns, Jerry L.; Ye, XiBiao; McCann, Patricia J.; Lindstrom, Andrew B.

    2009-11-15

    A rigorous solid phase extraction/liquid chromatography/tandem mass spectrometry method for the measurement of 10 perfluorinated compounds (PFCs) in fish fillets is described and applied to fillets of bluegill sunfish (Lepomis macrochirus) collected from selected areas of Minnesota and North Carolina. The 4 PFC analytes routinely detected in bluegill fillets were perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (C10), perfluoroundecanoic acid (C11), and perflurododecanoic acid (C12). Measures of method accuracy and precision for these compounds showed that calculated concentrations of PFCs in spiked samples differed by less than 20% from their theoretical values and that the %RSD for repeated measurements was less than 20%. Minnesota samples were collected from areas of the Mississippi River near historical PFC sources, from the St. Croix River as a background site, and from Lake Calhoun, which has no documented PFC sources. PFOS was the most prevalent PFC found in the Minnesota samples, with median concentrations of 47.0-102 ng/g at locations along the Mississippi River, 2.08 ng/g in the St. Croix River, and 275 ng/g in Lake Calhoun. North Carolina samples were collected from two rivers with no known historical PFC sources. PFOS was the predominant analyte in fish taken from the Haw and Deep Rivers, with median concentrations of 30.3 and 62.2 ng/g, respectively. Concentrations of C10, C11, and C12 in NC samples were among the highest reported in the literature, with respective median values of 9.08, 23.9, and 6.60 ng/g in fish from the Haw River and 2.90, 9.15, and 3.46 ng/g in fish from the Deep River. These results suggest that PFC contamination in freshwater fish may not be limited to areas with known historical PFC inputs.

  2. Immobilising effect of Ruta graveolens L. on human spermatozoa: coumarin compounds are involved.

    PubMed

    Naghibi Harat, Z; Lakpour, N; Sadeghipoor, H R; Kamalinejad, M; Eshraghian, M R; Naghibi, B; Akhondi, M M; Binaafar, S; Sadeghi, M R

    2015-12-01

    This study was designed to find out Ruta graveolens L. functional components, which have immobilisation effect on human spermatozoa for contraceptive use. A five-step fractionation method was used to derive different components from rue aqueous extract by using hexane, chloroform, ethanol, acetone and ultrapure water. Gas chromatography-mass spectrophotometery (GC-MS) of all fractions and the aqueous extract were performed to determine the chemical components. The immobilisation assay and membrane integrity test were also performed with four different coumarins, which were found in GC-MS in a concentration of 10 μm. Hexane, chloroform, acetone and ethanol fractions could significantly decrease motility of sperms within the first and the second hours. Hexane fraction had also significant immediate effect. The aqueous fraction had no effect on sperm motility. Meanwhile, GC-MS revealed that aqueous extract and effective fractions had similar coumarin compounds. We performed the immobilisation assay on four different coumarins, which were found in GC-MS in a concentration of 10 μm. Reduction of sperm motility was only significant for xanthotoxin. In the sperm viability and membrane integrity tests, hexane and ethanolic fractions could impair sperm vitality significantly, in contrast to coumarins. These results indicated that a part of immobilising effect of rue could be due to its coumarins. The possible mechanism could be blocking of spermatozoa potassium channels.

  3. Effects of Substrate, Protein Environment, and Proximal Ligand Mutation on Compound I and Compound 0 of Chloroperoxidase

    NASA Astrophysics Data System (ADS)

    Lai, Wenzhen; Chen, Hui; Cho, Kyung-Bin; Shaik, Sason

    2009-07-01

    This paper investigates the enzyme chloroperoxidase (CPO) by means of hybrid quantum mechanical/molecular mechanical (QM/MM) calculations. The effects of anionic substrate, protein environment, and proximal ligand mutation on the high-valent iron-oxo species, compound I (Cpd I), and the ferric hydroperoxide complex, compound 0 (Cpd 0), are studied. The results indicate that the presence of an anionic substrate (acetate) and the protonation state of one critical residue (Glu104) have a considerable impact on the relative stabilities of Cpd I and Cpd 0. In the absence of the substrate or when the substrate is protonated, Cpd I is considerably more stable, and its formation barrier is smaller than in the case where the substrate is in its anionic state and when Glu104 is deprotonated. This trend, which is shown to be a simple manifestation of the Hammond principle, reproduces the experimental observation that the working pH of the enzyme is acidic. Furthermore, in the absence of substrate (or when it is protonated), the relative Cpd 0/Cpd I energies are found to be a good index of Cpd I stability in heme enzymes and to follow the experimental order: horseradish peroxidase (HRP) > CPO > P450. In silico mutation of the proximal ligand from cysteine to selenocysteine was found to have no effect at all on the properties of Cpd I (e.g., spin density on the chalcogen, Mössbauer parameters, etc.) and its relative stability to Cpd 0 or on the corresponding barrier for formation. This surprising finding shows that the polar CPO pocket applies a leveling effect that stabilizes the anionic forms of the proximal ligands (CysS- and CysSe-). This in turn means that the Se-Cpd I of the mutant CPO is observable.

  4. Simple Method for Determination of Oxidation Numbers of Atoms in Compounds.

    ERIC Educational Resources Information Center

    Kauffman, Joel M.

    1986-01-01

    Presents the exploded structure method for determination of oxidation states in covalently bound atoms. The three step method is illustrated with four examples and compared to popular textbook presentations. (JM)

  5. Effect of oxygenated sterol compounds on human bone marrow granulocytic progenitor cells

    SciTech Connect

    Hoffman, P.C.; Richman, C.M.; Hsu, R.C.; Chung, J.; Scanu, A.M.; Yachnin, S.

    1981-01-01

    Oxygenated sterol compounds are potent inhibitors of sterol and DNA synthesis in mammalian cells. We studied the effects of oxygenated sterols on human marrow granulocytic progenitor cells in vitro (CFU-C)*. 25-Hydroxycholesterol, as well as 6-ketocholestanol, 7-ketocholesterol, and 20 ..cap alpha..-hydroxycholesterol, demonstrated marked inhibition of CFU-C proliferation. The latter effect, which was not a result of direct cytoxicity of the compounds, was reversible by cholesterol, but not by mevalonic acid. We conclude that inhibition of sterol synthesis by oxygenated sterol compounds may be insufficient to explain their suppression of CFU-C proliferation.

  6. Effects of compounds in leaves of Salix matsudana on arachidonic acid metabolism.

    PubMed

    Zheng, Yi-Nan; Zhang, Jing; Han, Li-Kun; Sekiya, Keizo; Kimura, Yoshiyuki; Okuda, Hiromichi

    2005-12-01

    Apigenin 7-O-beta-D-glucopyranuronide (1), luteolin 7-O-beta-D-glucopyranuronide (2), m-hydroxybenzyl beta-D-glucoside (3), and chrysoeriol 7-O-beta-D-glucopyranuronide (4) were isolated for the first time from the leaves of Salix matsudana. Furthermore, the effects of compounds 1, 2 and 3 on arachidonic acid metabolism were studied. These compounds inhibited significantly the production of 12-hydroxy-5, 8, 10, 14-eicosatetraenoic acid (12-HETE). In addition, the aglycon apigenin inhibited not only 12-HETE but also thromboxane B(2) (TXB(2)). The effect of compound (4) on arachidonic acid metabolism is now under investigation. PMID:16327246

  7. Characterization of Bioactive Compounds in Tunisian Bitter Orange (Citrus aurantium L.) Peel and Juice and Determination of Their Antioxidant Activities

    PubMed Central

    Jabri karoui, Iness; Marzouk, Brahim

    2013-01-01

    Citrus aurantium peel and juice aroma compounds were investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), whereas phenolic compounds analysis was performed by reversed-phase high-performance liquid chromatography (RP-HPLC). Limonene was the major volatile compound of bitter orange peel (90.25%) and juice (91.61%). HPLC analysis of bitter orange peel and juice methanolic extracts indicated that phenolic acids constitute their main phenolic class representing 73.80% and 71.25%, respectively, followed by flavonoids (23.02% and 23.13%, resp.). p-Coumaric and ferulic acids were the most abundant phenolic compounds representing 24.68% and 23.79%, respectively, in the peel, while the juice contained 18.02% and 19.04%, respectively. The antioxidant activities of bitter orange peel and juice methanolic extracts have been evaluated using four in vitro assays, and the results were compared with the standard antioxidants (BHT, BHA, and ascorbic acid). Our findings demonstrated that Citrus aurantium peel and juice possess antioxidant activities which were less effective than those of antioxidant standards. Both extracts may be suggested as a new potential source of natural antioxidant. PMID:23841062

  8. Characterization of bioactive compounds in Tunisian bitter orange (Citrus aurantium L.) peel and juice and determination of their antioxidant activities.

    PubMed

    Jabri Karoui, Iness; Marzouk, Brahim

    2013-01-01

    Citrus aurantium peel and juice aroma compounds were investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), whereas phenolic compounds analysis was performed by reversed-phase high-performance liquid chromatography (RP-HPLC). Limonene was the major volatile compound of bitter orange peel (90.25%) and juice (91.61%). HPLC analysis of bitter orange peel and juice methanolic extracts indicated that phenolic acids constitute their main phenolic class representing 73.80% and 71.25%, respectively, followed by flavonoids (23.02% and 23.13%, resp.). p-Coumaric and ferulic acids were the most abundant phenolic compounds representing 24.68% and 23.79%, respectively, in the peel, while the juice contained 18.02% and 19.04%, respectively. The antioxidant activities of bitter orange peel and juice methanolic extracts have been evaluated using four in vitro assays, and the results were compared with the standard antioxidants (BHT, BHA, and ascorbic acid). Our findings demonstrated that Citrus aurantium peel and juice possess antioxidant activities which were less effective than those of antioxidant standards. Both extracts may be suggested as a new potential source of natural antioxidant.

  9. The Effects of Smartphone Use on Organic Chemical Compound Learning

    ERIC Educational Resources Information Center

    Zan, Nuray

    2015-01-01

    As a result of rapid technological advances, smartphones have recently enjoyed widespread use. The basic purpose of this study is to examine the effects of smartphones when they are used as educational tools in learning environments. To assess the effects of smartphone use on learning, this study uses smartphones as educational tools in a…

  10. [Determination of volatile organic compounds in ambient air by thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry].

    PubMed

    Feng, Lili; Hu, Xiaofang; Yu, Xiaojuan; Zhang, Wenying

    2016-02-01

    A method was established for the simultaneous determination of 23 volatile organic compounds (VOCs) in ambient air with combination of thermal desorption (TD) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). The air samples were collected by active sampling method using Tenax-TA sorbent tubes, and desorbed by thermal desorption. The analytes were determined by GC-MS/MS in selected reaction monitoring (SRM) mode, and internal standard method was applied to quantify the VOCs. The results of all the 23 VOCs showed good linearities in low level (0. 01-1 ng) and high level (1-100 ng) with all the correlation coefficients (r2) more than 0. 99. The method quantification limits were between 0. 000 08-1 µg/m3. The method was validated by means of recovery experiments (n = 6) at three spiked levels of 2, 10 and 50 ng. The recoveries between 77% and 124% were generally obtained. The relative standard deviations (RSDs) in all cases were lower than 20%, except for chlorobenzene at the low spiked level. The developed method was applied to determine VOCs in ambient air collected at three sites in Shanghai. Several compounds, like benzene, toluene, ethylbenzene, m-xylenes, p-xylenes, styrene, 1, 2, 4-trimethylbenzene and hexachlorobutadiene were detected and confirmed in all the samples analyzed. The method is highly accurate, reliable and sensitive for monitoring the VOCs in ambient air. PMID:27382728

  11. Feasibility of a simple laboratory approach for determining temperature influence on SPMD-air partition coefficients of selected compounds

    USGS Publications Warehouse

    Cicenaite, A.; Huckins, J.N.; Alvarez, D.A.; Cranor, W.L.; Gale, R.W.; Kauneliene, V.; Bergqvist, P.-A.

    2007-01-01

    Semipermeable membrane devices (SPMDs) are a widely used passive sampling methodology for both waterborne and airborne hydrophobic organic contaminants. The exchange kinetics and partition coefficients of an analyte in a SPMD are mediated by its physicochemical properties and certain environmental conditions. Controlled laboratory experiments are used for determining the SPMD-air (Ksa's) partition coefficients and the exchange kinetics of organic vapors. This study focused on determining a simple approach for measuring equilibrium Ksa's for naphthalene (Naph), o-chlorophenol (o-CPh) and p-dichlorobenzene (p-DCB) over a wide range of temperatures. SPMDs were exposed to test chemical vapors in small, gas-tight chambers at four different temperatures (-16, -4, 22 and 40 ??C). The exposure times ranged from 6 h to 28 d depending on test temperature. Ksa's or non-equilibrium concentrations in SPMDs were determined for all compounds, temperatures and exposure periods with the exception of Naph, which could not be quantified in SPMDs until 4 weeks at the -16 ??C temperature. To perform this study the assumption of constant and saturated atmospheric concentrations in test chambers was made. It could influence the results, which suggest that flow through experimental system and performance reference compounds should be used for SPMD calibration. ?? 2006 Elsevier Ltd. All rights reserved.

  12. Feasibility of a simple laboratory approach for determining temperature influence on SPMD–air partition coefficients of selected compounds

    USGS Publications Warehouse

    Cicenaite, Aurelija; Huckins, James N.; Alvarez, David A.; Cranor, Walter L.; Gale, Robert W.; Kauneliene, Violeta; Bergqvist, Per-Anders

    2007-01-01

    Semipermeable membrane devices (SPMDs) are a widely used passive sampling methodology for both waterborne and airborne hydrophobic organic contaminants. The exchange kinetics and partition coefficients of an analyte in a SPMD are mediated by its physicochemical properties and certain environmental conditions. Controlled laboratory experiments are used for determining the SPMD–air (Ksa's) partition coefficients and the exchange kinetics of organic vapors. This study focused on determining a simple approach for measuring equilibrium Ksa's for naphthalene (Naph), o-chlorophenol (o-CPh) and p-dichlorobenzene (p-DCB) over a wide range of temperatures. SPMDs were exposed to test chemical vapors in small, gas-tight chambers at four different temperatures (−16, −4, 22 and 40 °C). The exposure times ranged from 6 h to 28 d depending on test temperature. Ksa's or non-equilibrium concentrations in SPMDs were determined for all compounds, temperatures and exposure periods with the exception of Naph, which could not be quantified in SPMDs until 4 weeks at the −16 °C temperature. To perform this study the assumption of constant and saturated atmospheric concentrations in test chambers was made. It could influence the results, which suggest that flow through experimental system and performance reference compounds should be used for SPMD calibration.

  13. Climatic effects due to halogenated compounds in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Wang, W.-C.; Pinto, J. P.; Yung, Y. L.

    1980-01-01

    Using a one-dimensional radiative-convective model, a sensitivity study is performed of the effect of ozone depletion in the stratosphere on the surface temperature. There could be a cooling of the surface temperature by approximately 0.2 K due to chlorofluoromethane-induced ozone depletion at steady state (assuming 1973 release rates). This cooling reduces significantly the greenhouse effect due to the presence of chlorofluoromethanes. Carbon tetrafluoride has a strong nu sub 3 band at 7.8 microns, and the atmospheric greenhouse effect is shown to be 0.07 and 0.12 K/ppbv with and without taking into account overlap with CH4 and N2O bands. At concentrations higher than 1 ppbv, absorption by the nu sub 3 band starts to saturate and the greenhouse effect becomes less efficient.

  14. Determination of solubility products of complex compounds of certain lanthanide and actinide diiodies with 18-crown-6 in tetrahydrofuran

    SciTech Connect

    Mikheev, N.B.; Kamenskaya, A.N.; Kulyukhin, S.A.

    1988-09-01

    The existence of divalent americium in a tetrahydrofuran (THF) solution was proved for the first time. The values of the solubility products (SP) of the complex compounds with the composition of MeI{sub 2}{centered dot}18-crown-6 (Me = Sm, Eu, Yb, Am, Cf, Es, Fm) in the THF solutions were determined by the cocrystallization method. The SP values obtained are within (5.9-7.9){centered dot}10{sup {minus}12} and are close to the SP value for SrI{sub 2}{centered dot}10{sup {minus}12}, which indicates a similarity in the properties of these elements.

  15. Antioxidant and Antiinflammatory Compounds in Nutmeg (Myristicafragrans) Pericarp as Determined by in vitro Assays.

    PubMed

    Zhang, Chuan-rui; Jayashre, Ettannil; Kumar, Paramasivam Suresh; Nair, Muraleedharan G

    2015-08-01

    Nutmeg, Myristicafragrans, is known for its culinary and medicinal values. The nutmeg pericarp, abundant during the production of the seed, is also used in food and beverage preparations. In this study, the pericarp of M. fragrans was evaluated for its bioactive components using in vitro antioxidant and antiinflammatory assays. The hexane, ethyl acetate and methanolic extracts inhibited lipid peroxidation (LPO) by 82.5, 70.1 and 73.2%, and cyclooxygenase enzymes COX-1 by 44, 44 and 42% and COX-2 by 47, 41 and 36%, respectively, at 100 microg/mL. The bioassay-guided purifications of extracts yielded 20 compounds belonged to neolignans (0.13%), phenylpropanoids (0.28%), phenolic aldehyde (0.35%), triterpenoids (0.06%), triglycerides (0.20%), sugars (10.2%) and steroids (0.49%). Pure isolates 1-5 inhibited LPO by 70-99% and 3-12 inhibited COX-1 and -2 enzymes by 37-49%. This is the first report on the bioassay-guided characterization of constituents in nutmeg pericarp. Our results support the medicinal claims of nutmeg pericarp.

  16. Methods for the determination of organic compounds in drinking water, Supplement 1

    SciTech Connect

    Not Available

    1990-07-01

    Nine analytical methods covering 54 organic contaminants which may be present in drinking water or drinking water sources are described in detail. Seven of these methods cover compounds designated for regulation under the Safe Drinking Water Act Amendments of 1986. Regulations for this group are in the proposal stages with promulgation scheduled for June 1992. The other two methods are for chlorination disinfection byproducts and may be regulated as part of EPA's disinfectants and disinfectant byproducts rule scheduled for proposal early in 1992. Most of the analytes may be classified as non-volatile and three of the methods entail separations by high performance liquid chromatography. The remainder employ capillary column gas chromatography. One of these requires detection of a potentially very toxic contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin, at the low parts per trillion level. Labeled isotopes of this analyte are employed as tracers and high resolution mass spectrometry is required for detection and unambiguous identification. Three of the methods herein offer new and simplified liquid-solid extraction procedures, a trend which is likely to become even more pronounced in the future.

  17. Antioxidant and Antiinflammatory Compounds in Nutmeg (Myristicafragrans) Pericarp as Determined by in vitro Assays.

    PubMed

    Zhang, Chuan-rui; Jayashre, Ettannil; Kumar, Paramasivam Suresh; Nair, Muraleedharan G

    2015-08-01

    Nutmeg, Myristicafragrans, is known for its culinary and medicinal values. The nutmeg pericarp, abundant during the production of the seed, is also used in food and beverage preparations. In this study, the pericarp of M. fragrans was evaluated for its bioactive components using in vitro antioxidant and antiinflammatory assays. The hexane, ethyl acetate and methanolic extracts inhibited lipid peroxidation (LPO) by 82.5, 70.1 and 73.2%, and cyclooxygenase enzymes COX-1 by 44, 44 and 42% and COX-2 by 47, 41 and 36%, respectively, at 100 microg/mL. The bioassay-guided purifications of extracts yielded 20 compounds belonged to neolignans (0.13%), phenylpropanoids (0.28%), phenolic aldehyde (0.35%), triterpenoids (0.06%), triglycerides (0.20%), sugars (10.2%) and steroids (0.49%). Pure isolates 1-5 inhibited LPO by 70-99% and 3-12 inhibited COX-1 and -2 enzymes by 37-49%. This is the first report on the bioassay-guided characterization of constituents in nutmeg pericarp. Our results support the medicinal claims of nutmeg pericarp. PMID:26434127

  18. Quantification of biogenic volatile organic compounds with a flame ionization detector using the effective carbon number concept

    NASA Astrophysics Data System (ADS)

    Faiola, C. L.; Erickson, M. H.; Fricaud, V. L.; Jobson, B. T.; VanReken, T. M.

    2012-03-01

    Biogenic volatile organic compounds (BVOCs) are emitted into the atmosphere by plants and include isoprene, monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are among the principal factors influencing the oxidative capacity of the atmosphere in forested regions. BVOC emission rates are often measured by collecting samples onto adsorptive cartridges in the field and then transporting these samples to the laboratory for chromatographic analysis. One of the most commonly used detectors in chromatographic analysis is the flame ionization detector (FID). For quantitative analysis with an FID, relative response factors may be estimated using the effective carbon number (ECN) concept. The purpose of this study was to determine the ECN for a variety of terpenoid compounds to enable improved quantification of BVOC measurements. A dynamic dilution system was developed to make quantitative gas standards of VOCs with mixing ratios from 20-55 ppb. For each experiment using this system, one terpene standard was co-injected with an internal reference, n-octane, and analyzed via an automated cryofocusing system interfaced to a gas chromatograph flame ionization detector and mass spectrometer (GC/MS/FID). The ECNs of 16 compounds (14 BVOCs) were evaluated with this approach, with each test compound analyzed at least three times. The difference between the actual carbon number and measured ECN ranged from -24% to -2%. The difference between theoretical ECN and measured ECN ranged from -22% to 9%. Measured ECN values were within 10% of theoretical ECN values for most terpenoid compounds.

  19. Quantification of biogenic volatile organic compounds with a flame ionization detector using the effective carbon number concept

    NASA Astrophysics Data System (ADS)

    Faiola, C. L.; Erickson, M. H.; Fricaud, V. L.; Jobson, B. T.; VanReken, T. M.

    2012-08-01

    Biogenic volatile organic compounds (BVOCs) are emitted into the atmosphere by plants and include isoprene, monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are among the principal factors influencing the oxidative capacity of the atmosphere in forested regions. BVOC emission rates are often measured by collecting samples onto adsorptive cartridges in the field and then transporting these samples to the laboratory for chromatographic analysis. One of the most commonly used detectors in chromatographic analysis is the flame ionization detector (FID). For quantitative analysis with an FID, relative response factors may be estimated using the effective carbon number (ECN) concept. The purpose of this study was to determine the ECN for a variety of terpenoid compounds to enable improved quantification of BVOC measurements. A dynamic dilution system was developed to make quantitative gas standards of VOCs with mixing ratios from 20-55 ppb. For each experiment using this system, one terpene standard was co-injected with an internal reference, n-octane, and analyzed via an automated cryofocusing system interfaced to a gas chromatograph flame ionization detector and mass spectrometer (GC/MS/FID). The ECNs of 16 compounds (14 BVOCs) were evaluated with this approach, with each test compound analyzed at least three times. The difference between the actual carbon number and measured ECN ranged from -24% to -2%. The difference between theoretical ECN and measured ECN ranged from -22% to 9%. Measured ECN values were within 10% of theoretical ECN values for most terpenoid compounds.

  20. Development and Validation of an HPLC-UV Method for Determination of Eight Phenolic Compounds in Date Palms.

    PubMed

    Al-Rimawi, Fuad; Odeh, Imad

    2015-01-01

    A simple, precise, accurate, and selective method was developed and validated for determination of eight phenolic compounds (gallic acid, p-hydroxybenzoic acid, vanilic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and sinapic acid) in date palms. Separation was achieved on an RP C18 column using the mobile phase methanol-water with 2% acetic acid (18+82, v/v). This method was validated according to the requirements for new methods, which include accuracy, precision, selectivity, robustness, LOD, LOQ, linearity, and range. The method demonstrated good linearity over the range 1-1000 ppm of gallic acid, p-hydroxybenzoic acid, vanilic acid, caffeic acid, and syringic acid with r2 greater than 0.99, and in the range of 3-1000 ppm for p-coumaric acid, ferulic acid, and sinapic acid with r2 greater than 0.99. The recovery of the eight phenolic compounds ranged from 97.1 to 102.2%. The method is selective because adjacent peaks of phenolic compounds were well separated with good resolution. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operators proved that the method is robust and rugged.

  1. Simultaneous determination of four neuroprotective compounds of Tilia amurensis by high performance liquid chromatography coupled with diode array detector

    PubMed Central

    Lee, Bohyung; Weon, Jin Bae; Yun, Bo-Ra; Lee, Jiwoo; Eom, Min Rye; Ma, Choong Je

    2014-01-01

    Background: Tilia amurensis consists of various compounds, such as flavonoids and terpenoids. Objective: A simple and reliable high performance liquid chromatography (HPLC) coupled with the diode array detector (DAD) method has been established for simultaneous determination of epicatechin, nudiposide, lyoniside, and scopoletin isolated from Tilia amurensis. Materials and Methods: Optimum separations were obtained with a SHISEIDO C18 column by gradient eluton, with 0.1% Trifluoroacetic acid (TFA) water-methanol as the mobile phase. The gradient elution system was completed within 40 minutes. The flow rate and detection wavelength were 1 mL/minute, 205 nm, 250 nm, and 280 nm, respectively. Results: Validation of the analytical method was evaluated by linearity, precision, and the accuracy test. The calibration curve was linear over the established range with R2 > 0.997. The limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.01-15.20 μg/mL and 0.03-46.06 μg/mL. The method exhibited an intraday and interday precision range of 96.25-105.66% and 93.52-109.92%, respectively (RSD <2.80%). The recoveries and relative standard deviation (RSD) of the four compounds in Tilia amurensis were in the range of 90.42-104.84% and 0.2-2.58%. Conclusion: This developed method was accurate and reliable for the quality evaluation of the four compounds isolated from Tilia amurensis. PMID:25210303

  2. Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

    PubMed Central

    Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

    2014-01-01

    Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings. PMID:24592162

  3. Development of an automated cylindrical ion trap mass spectrometer for the determination of atmospheric volatile organic compounds.

    PubMed

    Edwards, Gavin D; Shepson, P B; Grossenbacher, J W; Wells, J M; Patterson, G E; Barket, D J; Pressley, S; Karl, T; Apel, E

    2007-07-01

    Volatile organic compounds released from the biosphere are known to have a large impact on atmospheric chemistry. Field instruments for the detection of these trace gases are often limited by the lack of instrument portability and the inability to distinguish compounds of interest from background or other interfering compounds. We have developed an automated sampling and preconcentration system, coupled to a lightweight, low-power cylindrical ion trap mass spectrometer. The instrument was evaluated by measuring isoprene concentrations during a field campaign at the University of Michigan Biological Station PROPHET lab. Isoprene was preconcentrated by sampling directly into a short capillary column precooled without the aid of cryogens. The capillary column was then rapidly heated by moving the column to a preheated region to obtain fast separation of isoprene from other components, followed by detection with a cylindrical ion trap. This combination yielded a detection limit of approximately 80 ppt (parts per trillion) for isoprene with a measurement frequency of one sample every 11 min. The data obtained by the automated sampling and preconcentration system during the PROPHET 2005 campaign were compared to those of other field instruments measuring isoprene at this site in an intercomparison exercise. The intercomparisons suggest the new inlet system, when coupled with this ion trap detector, provides a viable field instrument for the fast, precise, and quantitative determination of isoprene and other trace gases over a variety of atmospheric conditions.

  4. The effect of pro-ecological procedures and insect foraging on the total content of phenol compounds in winter wheat.

    PubMed

    Lamparski, Robert; Balcerek, Maciej; Modnicki, Daniel; Kotwica, Karol; Wawrzyniak, Maria

    2015-06-01

    In laboratory conditions, the effect of pro-ecological procedures (application of effective microorganisms and Asahi SL biostimulator) and foraging by insects [cereal leaf beetle (Oulema melanopa L.) and bird cherry-oat aphid (Rhopalosiphum padi (L.)] on the total content of phenolic compounds in winter wheat, was studied. Correlations between the total content of phenolic compounds (determined by the Folin-Ciocalteau colorimetric method) expressed as the amount of pyrogallol in wheat plants: undamaged, damaged by O. melanopa, damaged by R. padi, the length of feeding scar left by cereal leaf beetle and the number of pricks made by actively feeding insects of bird cherry-oat aphid were analysed. The wheat was treated by EM inoculant and a biostimulator. The mode of application of the preparations used had a significant effect on level the total phenolic compounds in the undamaged wheat and the wheat exposed to foraging by the above-mentioned insects. The plants not exposed to insects foraging contained greater amounts of phenolic compounds than those exposed to the insects. The correlation between the total content of phenols in the wheat damaged by the insects in the 'no-choice' conditions, proved insignificant.

  5. Periodicity effects of axial waves in elastic compound rods

    NASA Astrophysics Data System (ADS)

    Nielsen, R. B.; Sorokin, S. V.

    2015-09-01

    Floquet analysis is applied to the Bernoulli-Euler model for axial waves in a periodic rod. Explicit asymptotic formulae for the stop band borders are given and the topology of the stop band pattern is explained. Eigenfrequencies of the symmetric unit cell are determined by the Phase-closure Principle, and their correspondence with stop band formation is shown. Steady-state and transient dynamics of a periodic rod of finite length are analysed numerically and the difference in structural response when excitation is done in either stop- or pass bands is demonstrated. A physical interpretation of the underlying mechanisms of stop bands is proposed.

  6. Theoretical study of the effect of N-oxides on the performances of energetic compounds.

    PubMed

    Lai, Wei-peng; Lian, Peng; Ge, Zhong-xue; Liu, Ying-zhe; Yu, Tao; Lv, Jian

    2016-04-01

    In order to study the effects of N-oxide on structure and performance, six categories of energetic compounds were systemically investigated. The results indicated that the C-C bonds in the rings were shortened, and the C-N bonds close to the N → O bond were elongated when N atoms was oxidized to form N → O bonds. N → O bonds can increase the densities of most categories of compounds, and the increment will increase with the number of N → O bonds. As to their detonation performances, almost all categories of compounds had an increased trend, except for some NO2-, NHNO2- and ONO2-substituted compounds. The contribution of 1,2,3,4-tetrazine and 1,2,4,5-tetrazine to performances was better than that of pyrazine and [1,2,5] oxadiazolo [3,4-b] pyrazine on the whole, and the groups, especially energetic groups, made a huge contribution to performance. When R was a NH2 or ONO2 group, all compounds had lower impact sensitivities, and thus represent candidates for novel energetic compounds. However, other than the sixth category of compounds, all compounds had higher impact sensitivities when R was a NO2 or NHNO2 group, and have little significance in application. PMID:26983612

  7. Theoretical study of the effect of N-oxides on the performances of energetic compounds.

    PubMed

    Lai, Wei-peng; Lian, Peng; Ge, Zhong-xue; Liu, Ying-zhe; Yu, Tao; Lv, Jian

    2016-04-01

    In order to study the effects of N-oxide on structure and performance, six categories of energetic compounds were systemically investigated. The results indicated that the C-C bonds in the rings were shortened, and the C-N bonds close to the N → O bond were elongated when N atoms was oxidized to form N → O bonds. N → O bonds can increase the densities of most categories of compounds, and the increment will increase with the number of N → O bonds. As to their detonation performances, almost all categories of compounds had an increased trend, except for some NO2-, NHNO2- and ONO2-substituted compounds. The contribution of 1,2,3,4-tetrazine and 1,2,4,5-tetrazine to performances was better than that of pyrazine and [1,2,5] oxadiazolo [3,4-b] pyrazine on the whole, and the groups, especially energetic groups, made a huge contribution to performance. When R was a NH2 or ONO2 group, all compounds had lower impact sensitivities, and thus represent candidates for novel energetic compounds. However, other than the sixth category of compounds, all compounds had higher impact sensitivities when R was a NO2 or NHNO2 group, and have little significance in application.

  8. Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode

    DOE PAGES

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-09-09

    Furanic and phenolic compounds are 20 lignocellulose-derived compounds known to inhibit to H2- and ethanol- producing microorganisms in dark fermentation. Bioelectrochemical conversion of furanic and phenolic compounds to electricity or H2 has recently been demonstrated as a productive method to use these compounds. However, potential inhibitory effect of furanic and phenolic compounds on exoelectrogenesis in bioelectrochemical systems is not well understood. This study systematically investigated the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) on exoelectrogenesis in the bioanode of a microbial electrolysis cell. A mixture of these five compounds atmore » an increasing initial total concentration from 0.8 to 8.0 g/L resulted in current decrease up to 91%. The observed inhibition primarily affected exoelectrogenesis, instead of non-exoelectrogenic biotransformation pathways (e.g., fermentation) of the five compounds. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. Tests with individual compounds show that all five parent compounds contributed to the observed inhibition by the mixture. The IC50 (concentration resulting in 50% current decrease) was estimated as 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. Nevertheless, these compounds below their non-inhibitory concentrations jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products of the mixture, inhibited exoelectrogens at high concentrations, but to a lesser extent than the parent compounds. Recovery of exoelectrogenesis from inhibition by all compounds was observed, except for catechol, which resulted in irreversible inhibition. The reversibility of inhibition, as well as the observed difference in recovery

  9. Determinants of Effective Cooling during Endovascular Hypothermia

    PubMed Central

    Lyden, Patrick; Ernstrom, Karin; Cruz-Flores, Salvador; Gomes, Joao; Grotta, James; Mullin, Anthony; Rapp, Karen; Raman, Rema; Wijman, Christine; Hemmen, Thomas

    2012-01-01

    Therapeutic hypothermia is a promising neuroprotective therapy with multiple mechanisms of action. We demonstrated the feasibility of thrombolysis combined with endovascular hypothermia, but not all patients achieved effective cooling. We sought to identify the factors that determined effective cooling. Methods In 26 patients who underwent endovascular hypothermia we computed 4 measures of effective cooling: time to reach target; Area-Under-the-Curve (AUC) 34 ratio; AUC-34; and AUC-35. Using multivariate regression, we examined the effects of age, weight, starting temperature, body mass index, body surface area (BSA) , gender, shivering, and total meperidine dose on the 4 outcome measures. Results In univariate analyses, all 4 outcome measures were significantly influenced by BSA (p<0.01 in all univariate analyses). Time to reach target temperature was quicker in older patients (p<0.01). Shivering and meperidine dose were highly intercorrelated (r=0.6, p<0.01) and both marginally influenced all 4 outcome measures. In multivariate analysis, AUC ratio and time to reach target temperature were significantly influenced by BSA (p<0.01) and meperidine (p<0.05); AUC-34 was influenced only by BSA (p<0.01). The AUC- 35 was influenced by BSA (p<0.01), shivering, and total meperidine dose (p<0.05). Conclusions The most important determinant of effective cooling during endovascular hypothermia is BSA; larger patients are more difficult to cool and maintain in therapeutic range. Older patients cool more quickly. Shivering was well controlled by the combination of meperidine, buspirone, and surface counter-warming and only minimally influenced cooling effectiveness. Future trials of therapeutic hypothermia may include added measures to cool larger patients more effectively. PMID:22466971

  10. Effect-Directed Analysis for the Antioxidant Compound in Salvia verticillata

    PubMed Central

    Nickavar, Bahman; Rezaee, Javad; Nickavar, Azar

    2016-01-01

    Salvia genus is one of the largest genera of the Lamiaceae family. Its species have been used for a wide variety of disorders in the local traditional medicine systems. Therefore, the genus has been the subject of several phytochemical and biological studies. The aim of the study was to identify the major antioxidant compound(s) from the methanol extract of Salvia verticillata using activity-guided fractionation. The crude extract showed strong antioxidant activities in DPPH and β-carotene/linoleic acid tests. The ethyl acetate fraction also exhibited a potent free radical scavenging activity compared to the other fractions. Further fractionation and purification of the ethyl acetate fraction using chromatography methods yielded a compound with high antioxidant capacity. The isolated active compound was determined as chrysoeriol. It showed a dose-dependent free radical scavenging activity with an IC50 (DPPH scavenging) value of 93.32 (80.23 – 108.57) mM.

  11. Effect-Directed Analysis for the Antioxidant Compound in Salvia verticillata.

    PubMed

    Nickavar, Bahman; Rezaee, Javad; Nickavar, Azar

    2016-01-01

    Salvia genus is one of the largest genera of the Lamiaceae family. Its species have been used for a wide variety of disorders in the local traditional medicine systems. Therefore, the genus has been the subject of several phytochemical and biological studies. The aim of the study was to identify the major antioxidant compound(s) from the methanol extract of Salvia verticillata using activity-guided fractionation. The crude extract showed strong antioxidant activities in DPPH and β-carotene/linoleic acid tests. The ethyl acetate fraction also exhibited a potent free radical scavenging activity compared to the other fractions. Further fractionation and purification of the ethyl acetate fraction using chromatography methods yielded a compound with high antioxidant capacity. The isolated active compound was determined as chrysoeriol. It showed a dose-dependent free radical scavenging activity with an IC50 (DPPH scavenging) value of 93.32 (80.23 - 108.57) mM. PMID:27610164

  12. Effect-Directed Analysis for the Antioxidant Compound in Salvia verticillata

    PubMed Central

    Nickavar, Bahman; Rezaee, Javad; Nickavar, Azar

    2016-01-01

    Salvia genus is one of the largest genera of the Lamiaceae family. Its species have been used for a wide variety of disorders in the local traditional medicine systems. Therefore, the genus has been the subject of several phytochemical and biological studies. The aim of the study was to identify the major antioxidant compound(s) from the methanol extract of Salvia verticillata using activity-guided fractionation. The crude extract showed strong antioxidant activities in DPPH and β-carotene/linoleic acid tests. The ethyl acetate fraction also exhibited a potent free radical scavenging activity compared to the other fractions. Further fractionation and purification of the ethyl acetate fraction using chromatography methods yielded a compound with high antioxidant capacity. The isolated active compound was determined as chrysoeriol. It showed a dose-dependent free radical scavenging activity with an IC50 (DPPH scavenging) value of 93.32 (80.23 – 108.57) mM. PMID:27610164

  13. Effects of acid-washing filter treatment on quantification of aerosol organic compounds

    NASA Astrophysics Data System (ADS)

    Yang, Liming; Lim, Jaehyun; Yu, Liya E.

    The tests of standard mixtures and four sets of atmospheric particulate samples showed that an acid-wash (AW) pretreatment of fluorocarbon-coated glass fiber filters prior to aerosol sampling enhanced the quantifiable organic compounds for more than 29% (or 66 ng m -3); in particular, 47-273 ng m -3 (21-366%) more water-soluble organic compounds (WSOCs) were measured. When the acid-pretreated filters were employed, up to nine more organic species were measured in the individual daily samples. Because the acid pretreatment reduced the metal contaminants in the glass fiber filters, using the AW filters for aerosol sampling allows higher extraction recoveries of organic compounds. Since the fingerprinting compounds were more accurately determined when the aerosol samples were collected on the AW filters, better assessment of emission sources and toxicity of air pollutants can be obtained.

  14. Protein binding studies with radiolabeled compounds containing radiochemical impurities. Equilibrium dialysis versus dialysis rate determination

    SciTech Connect

    Honore, B.

    1987-04-01

    The influence of radiochemical impurities in dialysis experiments with high-affinity ligands is investigated. Albumin binding of labeled decanoate (97% pure) is studied by two dialysis techniques. It is shown that equilibrium dialysis is very sensitive to the presence of impurities resulting in erroneously low estimates of the binding affinity and in inconsistent results at varying albumin concentrations. Dialysis rate determination is less sensitive to impurities.

  15. Supercritical fluid extraction and HPLC determination of relevant polyphenolic compounds in grape skin.

    PubMed

    Chafer, Amparo; Pascual-Martí, M Carmen; Salvador, Amparo; Berna, Angel

    2005-11-01

    The polyphenols determined are: (+)-catechin, (-)-epicatechin, rutin, quercetin and trans-resveratrol. Suitable conditions of supercritical fluid extraction were established using ethanol as a modifier of the polarity solvent (supercritical carbon dioxide). Final extraction conditions were: 20% v/v ethanol, 60degreesC, 250 bars and flow rate 2 mL/min. Static step time and dynamic step time were established using a selected grape skin sample. The extract was collected in water; the more polar polyphenols ((+)-catechin and (-)-epicatechin) remain in solution but rutin, quercetin and trans-resveratrol precipitate in this medium, thereby the solution of the extracted polyphenols was filtered. (+)-Catechin and (-)-epicatechin were determined in the liquid fraction, while the solid fraction, containing rutin, quercetin and trans-resveratrol, was solved with ethanol/H20 (40:60). HPLC determination was carried out at C18 stationary phase, with ethanol/water/acetic acid as mobile phases and UV-visible diode array detection. Due to the significant differences between the polarity of the polyphenols, two different mobile phases were used. An ethanol/water/acetic acid (5:93:2) mobile phase was used to determine (+)-catechin (280 nm) and (-)-epicatechin (280 nm). On the other hand, rutin (254 nm), quercetin (254 nm) and trans-resveratrol (306 nm) were resolved using ethanol/water/acetic acid (40:58:2) as mobile phase. Instrumental parameters were optimised and analytical parameters obtained. The analytical method was validated and applied to five different varieties of Vitis vinifera from the geographical area of Valencia.

  16. Effect of γ-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix

    NASA Astrophysics Data System (ADS)

    Shim, Sung-Lye; Hwang, In-Min; Ryu, Keun-Young; Jung, Min-Seok; Seo, Hye-young; Kim, Hee-Yeon; Song, Hyun-Pa; Kim, Jae-Hun; Lee, Ju-Woon; Byun, Myung-Woo; Kwon, Joong-Ho; Kim, Kyong-Su

    2009-07-01

    A study was carried out to find the effect of γ-irradiation on contents of volatile compounds from medicinal herb, Paeoniae Radix ( Paenia albiflora Pallas var. trichocarpa Bunge). The volatile compounds of control, 1, 3, 5 and 10 kGy irradiated samples were extracted by simultaneous steam distillation and extraction (SDE) method and analyzed by gas chromatograph-mass spectrometer. The major volatile compounds were paeonol, ( E)-carveol, ( E, E)-2,4-octadienal, methyl salicylate, myrtanol and eugenol acetate. Volatile compounds belonging to chemical classes of acids, alcohols, aldehydes, esters, hydrocarbons and miscellaneous were identified in all experimental samples. The types of volatile compounds in irradiated samples were similar to those of non-irradiated sample and the concentrations of these compounds differed between treatments. 1,3-Bis (1,1-dimethylethyl)-benzene was identified by using the selected ion monitoring (GC/MS-SIM) mode. The concentration of this compound increased with the increase of irradiation dose level. These results suggest that it could be used as the base data for the effect of γ-irradiation on medicinal herb.

  17. Analytical Determination of KDOC-Values of Polycyclic Musk Compounds with HS-SPME and GC/MS/MS

    NASA Astrophysics Data System (ADS)

    Böhm, L.; Düring, R.-A.

    2009-04-01

    Polycyclic musk compounds, used as fragrances in cosmetics and detergents, get into rivers via domestic wastewater and sewage treatment plants and with sewage sludge as fertilizer into soils. Because of their persistence and lipophilic character they accumulate in biota, so they are pollutants with environmental relevance. The coefficient KDOC is used to quantify the distribution of substances between aqueous phase and dissolved organic matter (DOM) which is quantified by the determination of dissolved organic carbon (DOC). DOM is of specific relevance for the transport and fate of persistent and lipophilic compounds in the environment. The affinity to DOM increases, the more lipophilic a substance is. So the environmental mobility is enhanced with increasing binding on DOM. For that reason, measured KDOC-values are important to predict the fate and behaviour of chemicals in the environment and should be used for environmental fate modelling purposes. LITZ ET AL. (2007) state that, to carry out a risk-assessment for polycyclic musk compounds, further research on their sorption-behaviour is necessary. For the determination of KDOC-values, different concentrations of humic acid were spiked with a multi-component stock solution. The samples were analysed with headspace solid-phase microextraction in combination with gas chromatography coupled with mass spectrometry (HS-SPME GC/MS/MS). The KDOC-values were calculated according to YABUTA ET AL. (2004). The method was validated with single substance stock solutions and with polycyclic aromatic hydrocarbons (PAHs). The results show that the method is applicable, repeatable and suitable to get KDOC-values for many substances very fast, cheap and solvent-free. With our results KDOC-values for polycyclic musk compounds were determined for the first time. Literature LITZ, N. TH., MüLLER, J. AND BöHMER, W. (2007): Occurrence of Polycyclic Musks in Sewage Sludge and their Behaviour in Soils and Plants. Part 2: Investigation

  18. [Effect of arsenic and its compounds on the circulatory system].

    PubMed

    Sieradzki, A; Skoczyńska, A; Andrzejak, R

    2000-01-01

    Arsenic is a metal which occurs widely in both occupational and physical environments. Therefore, its easy accessibility and high toxicity raise the question on whether arsenic, particularly in relatively small doses, can cause damage of relevant molecular, biochemical and clinical significance to the cardiovascular system. The present review is focused on the confirmed and potential mechanisms of arsenic effect on the function and structure of vascular endothelium (nitric oxide, peroxynitrite), its role in stimulating the oxidative species formation (hydroxyperoxide, superoxide and lipid peroxide formation), as well as in decreasing the antioxidative response (enzymes: superoxide dysmutase, catalase, glutation peroxidase), its cytotoxic effects, including immunotoxic properties, arsenic action in the signal transduction pathways network (kinases and DNA transcription factors), impact on cell proliferation, differentiation and apoptosis, not to mention its interference with DNA synthesis and repair processes. Apart from mechanisms of arsenic action, the article provides the up-to-date information on various cardiovascular diseases of the established or presumed arsenic origin.

  19. Isolation of a New Homomonoterpene from Madhuca pasquieri and Effect of Isolated Compounds on NO Production.

    PubMed

    Hoang, Le Son; Tran, Manh Hung; Nguyen, Van Thu; Ngo, Quynh Mai Thi; Lee, Joo-Sang; Rho, Seong-Soo; Kim, Jeong Ah; Lee, Jeong-Hyung; Woo, Mi Hee; Min, Byung Sun

    2016-06-01

    A new homomonoterpene, 1,3,3-trimethyl-7-oxabicyclo[3.1.1]hexa-9-en-10-oic acid, named madhusic acid A (1), together with ten known compounds (2-11) were isolated from the methanolic extract of the dried leaves of Madhuca pasquieri (Dubard) H. J. Lam. The structure of the new compound was elucidated on the basis of 1D, 2D NMR (COSY, HMQC, and HMBC) and mass spectral analyses. We examined the effects of the isolated compounds against LPS-induced NO production in macrophage RAW264.7 cells and compound 2 showed effective activity with an IC50 value of 14.5 μM. PMID:27534103

  20. Determination of selected pharmaceutical compounds in biosolids by supported liquid extraction and gas chromatography-tandem mass spectrometry.

    PubMed

    Albero, Beatriz; Sánchez-Brunete, Consuelo; Miguel, Esther; Aznar, Ramón; Tadeo, José L

    2014-04-01

    In this work, an analytical method was developed for the determination of pharmaceutical drugs in biosolids. Samples were extracted with an acidic mixture of water and acetone (1:2, v/v) and supported liquid extraction was used for the clean-up of extracts, eluting with ethyl acetate:methanol (90:10, v/v). The compounds were determined by gas chromatography-tandem mass spectrometry using matrix-match calibration after silylation to form their t-butyldimethylsilyl derivatives. This method presents various advantages, such as a fairly simple operation for the analysis of complex matrices, the use of inexpensive glassware and low solvent volumes. Satisfactory mean recoveries were obtained with the developed method ranging from 70 to 120% with relative standard deviations (RSDs) ≤ 13%, and limits of detection between 0.5 and 3.6 ng g(-1). The method was then successfully applied to biosolids samples collected in Madrid and Catalonia (Spain). Eleven of the sixteen target compounds were detected in the studied samples, at levels up to 1.1 μg g(-1) (salicylic acid). Ibuprofen, caffeine, paracetamol and fenofibrate were detected in all of the samples analyzed. PMID:24582395

  1. Simultaneous determination of 14 phenolic compounds in grape canes by HPLC-DAD-UV using wavelength switching detection.

    PubMed

    Zhang, Ang; Wan, Li; Wu, Cuiyun; Fang, Yulin; Han, Guomin; Li, Hua; Zhang, Zhenwen; Wang, Hua

    2013-11-18

    The paper described a novel chromatographic method for the simultaneous determination of phenolic compounds such as gallic, protocatechuic, vanillic, caffeic, syringic, p-coumaric and salicylic acid, (+)-catechin, (‒)-epicatechin, rutin, morin, quercetin, coumarin and trans-resveratrol at their maximum absorbance wavelengths (MAW) employing reverse-phase high performance liquid chromatography combined with DAD and UV detection via detection wavelength switching. The method was based on MAW acquisition by DAD and quantification by UV. The separation process was performed on a Shim-Pack VP-ODS C18 column (250 mm × 4.6 mm, 5 μm) held at 30 °C, utilizing 3.0% acetic acid and acetonitrile as mobile phase at a flow rate of 0.8 mL/min in the gradient elution mode. The method was fully validated in terms of linearity (r2 > 0.9990, 10‒350 mg/L), precision (both intra-day and inter-day RSD < 4.22%), accuracy (97.31%‒104.66%), specificity, robustness (0.59% < RSD < 2.86%), limit of detection and quantification. The switching method significantly improved the sensitivities of most phenolics studied in comparison with the standard constant wavelength detection (280 nm). The proposed method has been successfully applied to the determination of 14 phenolic compounds in 89 varieties of one-year-old Chinese grape one-year-canes. Grape canes contain many phenolics, especially trans-resveratrol, (‒)-epicatechin, and (+)-catechin.

  2. Determination of the misalignment error of a compound zero-order waveplate using the spectroscopic phase shifting method

    NASA Astrophysics Data System (ADS)

    Zheng, Quan; Han, Zhigang; Chen, Lei

    2016-09-01

    The spectroscopic phase shifting method was proposed to determine the misalignment error of a compound zero-order waveplate. The waveplate, which is composed of two separate multi-order quartz waveplates, was measured by a polarizer-waveplate-analyser setup with a spectrometer as the detector. The theoretical relationship between the misalignment error and the azimuth of the polarized light that emerged from the waveplate was studied by comparing two forms of the Jones matrix of the waveplate. Four spectra were obtained to determine the wavelength-dependent azimuth using a phase shifting algorithm when the waveplate was rotated to four detection angles. The misalignment error was ultimately solved from the wavelength-dependent azimuth by the Levenberg-Marquardt method. Experiments were conducted at six misalignment angles. The measured results of the misalignment angle agree well with their nominal values, indicating that the spectroscopic phase shifting method can be a reliable way to measure the misalignment error of a compound zero-order waveplate.

  3. Methylsulfonylmethane (MSM), an organosulfur compound, is effective against obesity-induced metabolic disorders in mice.

    PubMed

    Sousa-Lima, Inês; Park, Shin-Young; Chung, Michelle; Jung, Hyun Ju; Kang, Min-Cheol; Gaspar, Joana M; Seo, Ji A; Macedo, M Paula; Park, Kyong Soo; Mantzoros, Christos; Lee, Seung-Hoon; Kim, Young-Bum

    2016-10-01

    Methylsulfonylmethane (MSM), an organosulfur compound, has been used as a dietary supplement that can improve various metabolic diseases. However, the effect of MSM on obesity-linked metabolic disorders remains unclear. The goal of the current study is to determine whether MSM has beneficial effects on glucose and lipid homeostasis in obesity-associated pathophysiologic states. High-fat diet-induced obese (DIO) and genetically obese diabetic db/db mice treated with MSM (1%-5% v/v, by drinking water) were studied. Metabolic parameters involved in glucose and lipid metabolism were determined. Treatment of DIO mice with MSM leads to a significant decrease in blood glucose levels. DIO mice treated with MSM are hypersensitive to insulin, as evidenced by decreased serum insulin and an increase in the area above the curve during an ITT. Concurrently, MSM reduces hepatic triglyceride and cholesterol contents in DIO mice. These effects are accompanied by reductions in gene expression of key molecules involved in lipogenesis and inflammation. FACS analysis reveals that MSM markedly increases the frequency of B cells and decreases the frequency of myeloid cells in peripheral blood and in bone marrow. Moreover, overnutrition-induced changes of femur microarchitecture are restored by MSM. In db/db mice, a marked impairment in glucose and lipid metabolic profiles is notably ameliorated when MSM is supplemented. These data suggest that MSM has beneficial effects on multiple metabolic dysfunctions, including hyperglycemia, hyperinsulinemia, insulin resistance, and inflammation. Thus, MSM could be the therapeutic option for the treatment of obesity-related metabolic disorders such as type 2 diabetes and fatty liver diseases. PMID:27621186

  4. Separation and determination of benzene, toluene, ethylbenzene and o-xylene compounds in water using directly suspended droplet microextraction coupled with gas chromatography-flame ionization detector.

    PubMed

    Sarafraz-Yazdi, A; Amiri, A H; Es'haghi, Z

    2009-05-15

    The directly suspended droplet microextraction (DSDME) technique coupled with the capillary gas chromatography-flame ionization detector (GC-FID) was used to determine BTEX compounds in aqueous samples. The effective parameters such as organic solvent, extraction time, microdroplet volume, salt effect and stirring speed were optimized. The performance of the proposed technique was evaluated for the determination of BTEX compounds in natural water samples. Under the optimal conditions the enrichment factors ranged from 142.68 to 312.13, linear range; 0.01-20 microg mL(-1), limits of detection; 0.8-7 ng mL(-1) for most analytes. Relative standard deviations for 0.2 microg mL(-1) of BTEX in water were in the range 1.81-2.47% (n=5). The relative recoveries of BTEX from surface water at spiking level of 0.2 microg mL(-1) were in the range of 89.87-98.62%.

  5. Effect of cultivar and variety on phenolic compounds and antioxidant activity of cherry wine.

    PubMed

    Xiao, Zuobing; Fang, Lingling; Niu, Yunwei; Yu, Haiyan

    2015-11-01

    To compare the influence of cultivar and variety on the phenolic compounds and antioxidant activity (AA) of cherry wines, total phenolic (TP), total flavonoid (TF), total anthocyanin (TA), total tannin (TT), five individual phenolic acids, and AA were determined. An ultra-performance liquid chromatography tandem mass spectrometry (HPLC-DAD/ESI-MS) method was developed for the determination of gallic acid (GAE), p-hydroxybenzoic acid (PHB), chlorogenic acid (CHL), vanillic acid (VAN), and caffeic acid (CAF). A principal component analysis (PCA) and a cluster analysis (CA) were used to analyze differences related to cultivar and variety. The TP, TF, TA, TT, and AA of samples sourced from the Shandong province of China were higher than those from the Jiangsu province. The PCA and CA results showed that phenolic compounds in cherry wines were closely related to cultivar and variety and that cultivar had more influence on the phenolic compounds of cherry wines than variety. PMID:25976793

  6. Therapeutic effects of compound hypertonic saline on rats with sepsis.

    PubMed

    Dong, Fang; Chen, Wei; Xu, Liang; Wang, Huabing; Lu, Huizhi

    2014-01-01

    Sepsis is one of the major causes of death and is the biggest obstacle preventing improvement of the success rate in curing critical illnesses. Currently, isotonic solutions are used in fluid resuscitation technique. Several studies have shown that hypertonic saline applied in hemorrhagic shock can rapidly increase the plasma osmotic pressure, facilitate the rapid return of interstitial fluid into the blood vessels, and restore the effective circulating blood volume. Here, we established a rat model of sepsis by using the cecal ligation and puncture approach. We found that intravenous injection of hypertonic saline dextran (7.5% NaCl/6% dextran) after cecal ligation and puncture can improve circulatory failure at the onset of sepsis. We found that the levels of tumor necrosis factor-α, interleukin-1β, interleukin-6 and intracellular adhesion molecule 1 levels in the lung tissue of cecal ligation and puncture rats treated with hypertonic saline dextran were significantly lower than the corresponding levels in the control group. We inferred that hypertonic saline dextran has a positive immunoregulatory effect and inhibits the overexpression of the inflammatory response in the treatment of sepsis. The percentage of neutrophils, lung myeloperoxidase activity, wet to dry weight ratio of lung tissues, histopathological changes in lung tissues, and indicators of arterial blood gas analysis was significantly better in the hypertonic saline dextran-treated group than in the other groups in this study. Hypertonic saline dextran-treated rats had significantly improved survival rates at 9 and 18 h compared to the control group. Our results suggest that hypertonic saline dextran plays a protective role in acute lung injury caused after cecal ligation and puncture. In conclusion, hypertonic/hyperoncotic solutions have beneficial therapeutic effects in the treatment of an animal model of sepsis.

  7. Evaluation of a Screening System for Obesogenic Compounds: Screening of Endocrine Disrupting Compounds and Evaluation of the PPAR Dependency of the Effect

    PubMed Central

    Pereira-Fernandes, Anna; Demaegdt, Heidi; Vandermeiren, Karine; Hectors, Tine L. M.; Jorens, Philippe G.; Blust, Ronny; Vanparys, Caroline

    2013-01-01

    Recently the environmental obesogen hypothesis has been formulated, proposing a role for endocrine disrupting compounds (EDCs) in the development of obesity. To evaluate this hypothesis, a screening system for obesogenic compounds is urgently needed. In this study, we suggest a standardised protocol for obesogen screening based on the 3T3-L1 cell line, a well-characterised adipogenesis model, and direct fluorescent measurement using Nile red lipid staining technique. In a first phase, we characterised the assay using the acknowledged obesogens rosiglitazone and tributyltin. Based on the obtained dose-response curves for these model compounds, a lipid accumulation threshold value was calculated to ensure the biological relevance and reliability of statistically significant effects. This threshold based method was combined with the well described strictly standardized mean difference (SSMD) method for classification of non-, weak- or strong obesogenic compounds. In the next step, a range of EDCs, used in personal and household care products (parabens, musks, phthalates and alkylphenol compounds), were tested to further evaluate the obesogenicity screening assay for its discriminative power and sensitivity. Additionally, the peroxisome proliferator activated receptor γ (PPARγ) dependency of the positive compounds was evaluated using PPARγ activation and antagonist experiments. Our results showed the adipogenic potential of all tested parabens, several musks and phthalate compounds and bisphenol A (BPA). PPARγ activation was associated with adipogenesis for parabens, phthalates and BPA, however not required for obesogenic effects induced by Tonalide, indicating the role of other obesogenic mechanisms for this compound. PMID:24155963

  8. Radiation effects in x-irradiated hydroxy compounds

    SciTech Connect

    Budzinski, E.E.; Potter, W.R.; Box, H.C.

    1980-01-15

    Radiation effects are compared in single crystals of xylitol, sorbitol, and dulcitol x-irradiated at 4.2 /sup 0/K. In xylitol and dulcitol, but not in sorbitol, a primary oxidation product is identified as an alkoxy radical. ENDOR measurements detected three proton hyperfine couplings associated with the alkoxy ESR absorption, one of which is attributed to a proton three bond lengths removed from the seat of unpaired spin density. Intermolecular trapping of electrons is observed in all three crystals. ENDOR measurements were made of the hyperfine couplings between the trapped electron and the hydroxy protons forming the trap.

  9. Radiation effects in x-irradiated hydroxy compounds

    NASA Astrophysics Data System (ADS)

    Budzinski, Edwin E.; Potter, William R.; Box, Harold C.

    1980-01-01

    Radiation effects are compared in single crystals of xylitol, sorbitol, and dulcitol x-irradiated at 4.2 °K. In xylitol and dulcitol, but not in sorbitol, a primary oxidation product is identified as an alkoxy radical. ENDOR measurements detected three proton hyperfine couplings associated with the alkoxy ESR absorption, one of which is attributed to a proton three bond lengths removed from the seat of unpaired spin density. Intermolecular trapping of electrons is observed in all three crystals. ENDOR measurements were made of the hyperfine couplings between the trapped electron and the hydroxy protons forming the trap.

  10. Analytical methods for the endocrine disruptor compounds determination in environmental water samples.

    PubMed

    Locatelli, Marcello; Sciascia, Francesco; Cifelli, Roberta; Malatesta, Luciano; Bruni, Pantaleone; Croce, Fausto

    2016-02-19

    The potential risk of exposure to different xenobiotics, which can modulate the endocrine system and represent a treat for the wellness of an increasing number of people, has recently drawn the attention of international environmental and health agencies. Several agents, characterized by structural diversity, may interfer with the normal endocrine functions that regulate cell growth, homeostasis and development. Substances such as pesticides, herbicides, plasticizers, metals, etc. having endocrine activity (EDCs) are used in agriculture and industry and are also used as drugs for humans and animals. A difficulty in the analytical determination of these substances is the complexity of the matrix in which they are present. In fact, the samples most frequently analyzed consist of groundwater and surface water, including influent and effluent of wastewater treatment plants and drinking water. In this review, several sample pretreatment protocols, assays and different instrumental techniques recently used in the EDCs determination have been considered. This review concludes with a paragraph in which the most recent hyphenated-instrument techniques are treated, highlighting their sensitivity and selectivity for the analyses of environmental water samples.

  11. Determination of ideal-gas enthalpies of formation for key compounds: The 1989 project results

    NASA Astrophysics Data System (ADS)

    Steele, W. V.; Chirico, R. D.; Nguyen, A.; Hossenlopp, I. A.; Smith, N. K.

    1991-10-01

    The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor pressure measurements, and differential scanning calorimetric (dsc) heat capacity measurements. Ideal gas enthalpies of formation of (+ or -) butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene 2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 K before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group additivity parameters useful in the application of group contribution correlations are derived.

  12. Analytical methods for the endocrine disruptor compounds determination in environmental water samples.

    PubMed

    Locatelli, Marcello; Sciascia, Francesco; Cifelli, Roberta; Malatesta, Luciano; Bruni, Pantaleone; Croce, Fausto

    2016-02-19

    The potential risk of exposure to different xenobiotics, which can modulate the endocrine system and represent a treat for the wellness of an increasing number of people, has recently drawn the attention of international environmental and health agencies. Several agents, characterized by structural diversity, may interfer with the normal endocrine functions that regulate cell growth, homeostasis and development. Substances such as pesticides, herbicides, plasticizers, metals, etc. having endocrine activity (EDCs) are used in agriculture and industry and are also used as drugs for humans and animals. A difficulty in the analytical determination of these substances is the complexity of the matrix in which they are present. In fact, the samples most frequently analyzed consist of groundwater and surface water, including influent and effluent of wastewater treatment plants and drinking water. In this review, several sample pretreatment protocols, assays and different instrumental techniques recently used in the EDCs determination have been considered. This review concludes with a paragraph in which the most recent hyphenated-instrument techniques are treated, highlighting their sensitivity and selectivity for the analyses of environmental water samples. PMID:26805600

  13. Determination of ideal-gas enthalpies of formation for key compounds:

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A.; Smith, N.K.

    1991-10-01

    The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of ({plus minus})-butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene-2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 K before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group-additivity parameters useful in the application of group- contribution correlations are derived. 112 refs., 13 figs., 19 tabs.

  14. Studies on effective atomic numbers, electron densities from mass attenuation coefficients near the K edge in some samarium compounds.

    PubMed

    Akman, F; Durak, R; Turhan, M F; Kaçal, M R

    2015-07-01

    The effective atomic numbers and electron densities of some samarium compounds were determined using the experimental total mass attenuation coefficient values near the K edge in the X-ray energy range from 36.847 up to 57.142 keV. The measurements, in the region from 36.847 to 57.142 keV, were done in a transmission geometry utilizing the Kα2, Kα1, Kβ1 and Kβ2 X-rays from different secondary source targets excited by the 59.54 keV gamma-photons from an Am-241 annular source. This paper presents the first measurement of the effective atomic numbers and electron densities for some samarium compounds near the K edge. The results of the study showed that the measured values were in good agreement with the theoretically calculated ones. PMID:25880612

  15. Effect of Protozoa on Bacterial Degradation of an Aromatic Compound

    PubMed Central

    Huang, Tan-Chi; Chang, Miau-Chan; Alexander, Martin

    1981-01-01

    Prototrophic and growth factor-requiring strains of Alcaligenes spp. were used to study the effect of a protozoan, Tetrahymena pyriformis, on the degradation of p-aminobenzoate. The protozoan inhibited activity of the prototrophic bacterium by reducing its population size. For the growth factor-requiring strain of Alcaligenes, T. pyriformis provided the required growth factors so that the predator permitted the bacteria to grow and to continue p-aminobenzoate degradation. T. pyriformis inhibited bacterial activity when the amino acid supply was in excess, but activity of the auxotrophic strain of Alcaligenes was stimulated by the protozoan when the amino acid supply was limiting, although the bacterial population size was reduced by the protozoan. PMID:16345690

  16. English Compound and Non-Compound Processing in Bilingual and Multilingual Speakers: Effects of Dominance and Sequential Multilingualism

    ERIC Educational Resources Information Center

    González Alonso, Jorge; Villegas, Julián; García Mayo, María del Pilar

    2016-01-01

    This article reports on a study investigating the relative influence of the first language and dominant language (L1) on second language (L2) and third language (L3) morpho-lexical processing. A lexical decision task compared the responses to English NV-er compounds (e.g. "taxi driver") and non-compounds provided by a group of native…

  17. Effects of Morphology and Semantic Transparency on Typing Latencies in English Compound and Pseudocompound Words

    ERIC Educational Resources Information Center

    Gagné, Christina L.; Spalding, Thomas L.

    2016-01-01

    We used a typing task to measure the written production of compounds, pseudocompounds, and monomorphemic words on a letter-by-letter basis to determine whether written production (as measured by interletter typing speed) was affected by morphemic structure and semantic transparency of the constituents. Semantic transparency was analyzed using a…

  18. Effects of heat sink compounds on contact resistance of porous media

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High and low-conductivity heat sink compounds were applied in succession on a thermal probe, which was then used to determine the thermal conductivity and thermal diffusivity of some porous media at room temperature. The experiment was conducted separately under different packing densities and water...

  19. Stereoelectronic effects in the fragmentation of γ-silyloxy-β-hydroxy-α-diazocarbonyl compounds

    PubMed Central

    Jabre, Nitinkumar D.; Brewer, Matthias

    2012-01-01

    A series of γ-silyloxy-β-hydroxy-α-diazocarbonyl compounds were prepared as fragmentation substrates to probe the hypothesis that steric interactions between the diazo ester and adjacent silyloxy group can play an important role in determining the success of fragmentations. Proper stereoelectronic alignment of the diazo ester and the departing hydroxyl group is necessary for productive fragmentation to occur. PMID:23066902

  20. Determination of ideal-gas enthalpies of formation for key compounds: The 1988 project results

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A.; Smith, N.K.

    1990-07-01

    The results of a study aimed at improvement of group contribution methodology for estimation of thermodynamic properties of organic substances are reported. Specific weakness where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase and vapor-pressure measurements. Ideal-gas enthalpies of formation are reported for 3-methylbuta-1,2-diene; 2,5-dimethylhexa-2,4-diene; acetaldoxime; N,N-diethylhydroxylamine; 1-methylpyrrolidin-2-one; and phenanthrene. Solid and liquid-phase enthalpies of formation at 298.15 K are determined for benzamide. Ring corrections, group terms, and next-nearest-neighbor interaction terms useful in the application of group contribution correlations are derived. 54 refs., 2 figs., 21 tabs.

  1. Determination of ideal-gas enthalpies of formation for key compounds: The 1988 project results

    NASA Astrophysics Data System (ADS)

    Steele, W. V.; Chirico, R. D.; Nguyen, A.; Hossenlopp, I. A.; Smith, N. K.

    1990-07-01

    The results of a study aimed at improvement of group contribution methodology for estimation of thermodynamic properties of organic substances are reported. Specific weakness where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase and vapor pressure measurements. Ideal-gas enthalpies of formation are reported for 3-methylbuta 1,2-diene; 2,5-dimethylhexa 2,4-diene; acetaldoxime; N,N-diethyl hydroxylamine; 1-methylpyrrolidin-2-one; and phenanthrene. Solid and liquid phase enthalpies of formation at 298.15 K are determined for benzamide. Ring corrections, group terms, and next-nearest-neighbor interaction terms useful in the application of group contribution correlations are derived.

  2. Determination of the antioxidant activity of phenolic compounds by coulometric detection.

    PubMed

    Peyrat-Maillard, M N; Bonnely, S; Berset, C

    2000-04-01

    The combination of reversed-phase high-performance liquid chromatography with coulometric detection allows the detection of phenolic antioxidants in complex matrices like plant extracts with a high degree of sensitivity and selectivity. According to their voltammetric behaviour, phenolic acids and tocopherols show maximal detector response at low potentials (100-450 mV) while flavonoids show optimal response at two different potential values (one at 0-300 mV and one at 600-900 mV). The potential corresponding to maximal detector response (MDRP) of phenolic acids was shown to be inversely proportional to their antioxidant efficiency as determined in a lipidic model system under strong oxidizing conditions (110 degrees C, intensive oxygenation) or by the DPPH() test. However, such a relationship was not observed for flavonoids. PMID:18967903

  3. Are embryonic developing modes determinant in the acquisition and levels of photoprotective compounds in slipper limpets of the Crepipatella genus?

    PubMed

    Paredes-Molina, F J; Cubillos, V M; Montory, J A; Andrade-Villagrán, P A

    2016-09-01

    The type of embryonic development (mixed and direct) and its influence on the accumulation and translocation of photoprotective compounds from the mother to the encapsulated embryo was studied in the intertidal gastropods Crepipatella peruviana and Crepipatella dilatata during their reproductive peak. HPLC/MS was used to determine type and levels of sunscreen compounds (total carotenoids; TC/and mycosporine-like amino acid; MAA) in brooding females, capsule walls and early and pre-hatching embryos of both species. Photoprotective compounds were only quantified in nurse eggs of C. dilatata. Our results indicate that females of both species can accumulate TC and MAA at different levels, and they are able to transfer them selectively to capsule walls, embryos and nurse eggs. Palythine-serine (MW=244Da; λmax=320nm) and MAA-330 (MW=234Da; λmax=330nm) constitute total MAA pool in brooding females, whereas brooded embryos incorporate palythine (MW=244Da; λmax=320nm) to the MAA pool. Although TC was transferred from the mother to the embryo through the yolk in both species, MAA trespass showed differences. Females of C. peruviana transfer MAA to their embryos through the embryonic yolk; C. dilatata can transfer MAA only through their nurse eggs, which are consumed by embryos during the terminal stages of intracapsular development. Differences between mixed and direct embryonic development, as well as environmental UV-R levels, which the recently hatched larvae and juveniles of C. peruviana and C. dilatata are exposed to, would determine levels of sunscreen compounds in each species. Higher TC and MAA levels in pre-hatching larvae of C. peruviana compared to C. dilatata, indicate a necessity of C. peruviana for protection against UV-R radiation during approximately 15days when their veliger larvae remain in the water column before metamorphosis is complete. Conversely, low photoprotective levels in pre-hatching juveniles of C. dilatata could be related to low UV

  4. Are embryonic developing modes determinant in the acquisition and levels of photoprotective compounds in slipper limpets of the Crepipatella genus?

    PubMed

    Paredes-Molina, F J; Cubillos, V M; Montory, J A; Andrade-Villagrán, P A

    2016-09-01

    The type of embryonic development (mixed and direct) and its influence on the accumulation and translocation of photoprotective compounds from the mother to the encapsulated embryo was studied in the intertidal gastropods Crepipatella peruviana and Crepipatella dilatata during their reproductive peak. HPLC/MS was used to determine type and levels of sunscreen compounds (total carotenoids; TC/and mycosporine-like amino acid; MAA) in brooding females, capsule walls and early and pre-hatching embryos of both species. Photoprotective compounds were only quantified in nurse eggs of C. dilatata. Our results indicate that females of both species can accumulate TC and MAA at different levels, and they are able to transfer them selectively to capsule walls, embryos and nurse eggs. Palythine-serine (MW=244Da; λmax=320nm) and MAA-330 (MW=234Da; λmax=330nm) constitute total MAA pool in brooding females, whereas brooded embryos incorporate palythine (MW=244Da; λmax=320nm) to the MAA pool. Although TC was transferred from the mother to the embryo through the yolk in both species, MAA trespass showed differences. Females of C. peruviana transfer MAA to their embryos through the embryonic yolk; C. dilatata can transfer MAA only through their nurse eggs, which are consumed by embryos during the terminal stages of intracapsular development. Differences between mixed and direct embryonic development, as well as environmental UV-R levels, which the recently hatched larvae and juveniles of C. peruviana and C. dilatata are exposed to, would determine levels of sunscreen compounds in each species. Higher TC and MAA levels in pre-hatching larvae of C. peruviana compared to C. dilatata, indicate a necessity of C. peruviana for protection against UV-R radiation during approximately 15days when their veliger larvae remain in the water column before metamorphosis is complete. Conversely, low photoprotective levels in pre-hatching juveniles of C. dilatata could be related to low UV

  5. Anti-oxidative and cholinesterase inhibitory effects of leaf extracts and their isolated compounds from two closely related Croton species.

    PubMed

    Ndhlala, Ashwell R; Aderogba, Mutalib A; Ncube, Bhekumthetho; Van Staden, Johannes

    2013-02-01

    A comparative evaluation of the antioxidant and acetylcholinesterase inhibitory activity of the leaf extracts of Croton gratissimus and Croton zambesicus (subgratissimus) and compounds isolated from the extracts was carried out to determine their potential and suitability or otherwise as a substitute for each other in the management of oxidative and neurodegenerative conditions. Different antioxidant assays (DPPH, FRAP, β-carotene-linoleic and the lipid peroxidation models) and the microplate assay for acetylcholinesterase (AChE) inhibition were carried out separately to study the activities of the crude leaf extracts and four solvent fractions from each of the two Croton species. Bioassay guided fractionation was used to target antioxidant constituents of the crude extracts and ethyl acetate fractions of 20% aqueous methanol extract of C. gratissimus on silica gel and Sephadex LH-20 columns resulted in the isolation of kaempferol-3-O-β-6''(p-coumaroyl) glucopyranoside (tiliroside, 2), apigenin-6-C-glucoside (isovitexin, 3) and kampferol (4). The extract of C. zambesicus yielded quercetin-3-O-β-6''(p-coumaroyl) glucopyranoside-3'-methyl ether (helichrysoside- 3'-methyl ether, 1), kaempferol-3-O-β-6''(p-coumaroyl) glucopyranoside (tiliroside, 2) and apigenin-6-C-glucoside (isovitexin, 3). Three of the isolated compounds and their different combinations were also included in the bioassays. In all the assays performed, the antioxidant capacity and AChE inhibitory effects of C. zambesicus extracts were weaker than those of C. gratissimus. This suggests that C. gratissimus may not be substituted by C. zambesicus, despite the similarity in some of their constituents. Generally, the combinations made from the isolated compounds showed better activities in most of the assays compared to the individual isolated compounds. This suggests mechanisms such as synergism and/or additive effects to be taking place. This study established low, moderate and high antioxidant

  6. The Determination of Pesticidal and Non-Pesticidal Organotin Compounds by in situ Ethylation and Capillary Gas Chromatography with Pulsed Flame Photometric Detection

    EPA Science Inventory

    The concurrent determination of pesticidal and non-pesticidal organotin compounds in several water matrices, using a simultaneous in situ ethylation and liquid-liquid extraction followed by splitless injection mode capillary gas chromatography with pulsed flame photometric detect...

  7. The Determination of Pesticidal and Non-Pesticidal Organotin Compounds in Water Matrices by in situ Ethylation and Gas Chromatography with Pulsed Flame Photometric Detection

    EPA Science Inventory

    The concurrent determination of pesticidal and non-pesticidal organotin compounds in several water matrices, using a simultaneous in situ ethylation and liquid-liquid extraction followed by splitless injection mode capillary gas chromatography with pulsed flame photometric detect...

  8. Fast and simultaneous determination of endocrine disrupting compounds by ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Esteve, C; Herrero, L; Gómara, B; Quintanilla-López, J E

    2016-01-01

    A rapid and sensitive analytical method for the simultaneous determination of thirteen endocrine disruptors (five phthalates, seven parabens, and bisphenol A) in a single chromatographic run has been developed for the first time. The separation method, based on ultra-high performance liquid chromatography (UHPLC), allows the separation of all compounds (including isobaric pairs) in less than 4.1 min. The fast polarity switching mode of the triple quadrupole mass spectrometer used enables the registration of positive (phthalates) and negative (parabens and BPA) ions in the same acquisition run. A Response Surface Methodology was used for the optimization of the method. The optimum elution program starts with 0.2 min in isocratic conditions (79.8% water; 20% acetonitrile, 0.2% ammonium formate 5mM at pH 10.2), then the content of acetonitrile is linearly increased in 2 min up to 42%, and later up to 98% in 1.1 min. The analytical characteristics of the developed method were satisfactory. The method is robust and showed a linear response with determination coefficients (R(2)) higher than 0.991 in the range 5.0-2000 pg on column (or higher) for all the compounds investigated. Instrumental intra- and inter-day precision (expressed as relative standard deviation) were lower than 12% for parabens and bisphenol A, and between 5.9% and 27% for phthalates. Instrumental detection and quantification limits (iLODs and iLOQs) were in the range of medium-high femtograms (270-1300 pg on column for iLODs). Finally, the suitability of the developed method was demonstrated through its application to the analysis of commercial personal care products (shower gels) without any sample treatment, only a simple dilution, being possible to determine the simultaneous presence of phthalates, parabens, and bisphenol A in almost all the gels analyzed. PMID:26695271

  9. Full evaporation headspace gas chromatography for sensitive determination of high boiling point volatile organic compounds in low boiling matrices.

    PubMed

    Mana Kialengila, Didi; Wolfs, Kris; Bugalama, John; Van Schepdael, Ann; Adams, Erwin

    2013-11-01

    Determination of volatile organic components (VOC's) is often done by static headspace gas chromatography as this technique is very robust and combines easy sample preparation with good selectivity and low detection limits. This technique is used nowadays in different applications which have in common that they have a dirty matrix which would be problematic in direct injection approaches. Headspace by nature favors the most volatile compounds, avoiding the less volatile to reach the injector and column. As a consequence, determination of a high boiling solvent in a lower boiling matrix becomes challenging. Determination of VOCs like: xylenes, cumene, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMA), N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), benzyl alcohol (BA) and anisole in water or water soluble products are an interesting example of the arising problems. In this work, a headspace variant called full evaporation technique is worked out and validated for the mentioned solvents. Detection limits below 0.1 μg/vial are reached with RSD values below 10%. Mean recovery values ranged from 92.5 to 110%. The optimized method was applied to determine residual DMSO in a water based cell culture and DMSO and DMA in tetracycline hydrochloride (a water soluble sample).

  10. Determination of three anabolic compounds in calf urine by liquid chromatography with photodiode-array detection.

    PubMed

    Martín, Y

    2000-12-01

    A method for the determination of three anabolic hormones (diethylstilbestrol, dienestrol and trenbolone) in calf urine is described. After enzymatic hydrolysis, the samples were cleaned up by C18 solid-phase extraction. Drugs were extracted with hexane and analyzed by isocratic elution on a Discovery RP-Amide C16 5 microns column with photodiode-array detection at 240 and 347 nm. Both retention time and UV spectra were used for identification. Detection limits for the HPLC system were calculated to be 0.3 ng injected for all analytes in the standard mixture. However, for urine samples these limits increased because of the presence of unidentified matrix components. After extraction from urine, the limits of detection for the whole analytical procedure were 5 and 10 ng injected for trenbolone and stilbenes, respectively. The average recoveries of the hormones from spiked samples were in the range 53.1-56.7% with RSD between 11.3 and 14.5% for the whole procedure in the concentration range 25-2.5 ng ml-1.

  11. Determination of DDT and related compounds in blood samples from agricultural workers.

    PubMed

    Guardino, X; Serra, C; Obiols, J; Rosell, M G; Berenguer, M J; López, F; Brosa, J

    1996-01-01

    An analytical method combining a solid-phase (C18) clean-up and GC-electron-capture detection using a capillary column, was implemented to determine p,p'-DDT and its metabolites (p,p'-DDD and p,p'-DDE), as well as other organochlorine pesticides in whole blood samples from 30 farmers and 24 non-occupationally exposed workers. The average concentrations for the quantified pesticides, p,p'-DDT, p,p'-DDD and p,p'-DDE, were 0.9, 1.5 and 8.0 micrograms/l whole blood for exposed workers and 0.3, 0.5 and 3.3 micrograms/l for unexposed workers, respectively. GC-MS was used to confirm the identity of the pesticides found. Solid-phase extraction and the protocol used give a cleaner analytical matrix, not only improving sensitivity and resolution, but also allowing analyses with smaller blood samples as compared to other methods.

  12. Laccase biosensors based on different enzyme immobilization strategies for phenolic compounds determination.

    PubMed

    Casero, E; Petit-Domínguez, M D; Vázquez, L; Ramírez-Asperilla, I; Parra-Alfambra, A M; Pariente, F; Lorenzo, E

    2013-10-15

    Different enzyme immobilization approaches of Trametes versicolor laccase (TvL) onto gold surfaces and their influence on the performance of the final bioanalytical platforms are described. The laccase immobilization methods include: (i) direct adsorption onto gold electrodes (TvL/Au), (ii) covalent attachment to a gold surface modified with a bifunctional reagent, 3,3'-Dithiodipropionic acid di (N-succinimidyl ester) (DTSP), and (iii) integration of the enzyme into a sol-gel 3D polymeric network derived from (3-mercaptopropyl)-trimethoxysilane (MPTS) previously formed onto a gold surface (TvL/MPTS/Au). The characterization and applicability of these biosensors are described. Characterization is performed in aqueous acetate buffer solutions using atomic force microscopy (AFM), providing valuable information concerning morphological data at the nanoscale level. The response of the three biosensing platforms developed, TvL/Au, TvL/DTSP/Au and TvL/MPTS/Au, is evaluated in the presence of hydroquinone (HQ), used as a phenolic enzymatic substrate. All systems exhibit a clear electrocatalytic activity and HQ can be amperometrically determined at -0.10 V versus Ag/AgCl. However, the performance of biosensors - evaluated in terms of sensitivity, detection limit, linear response range, reproducibility and stability - depends clearly on the enzyme immobilization strategy, which allows establishing its influence on the enzyme catalytic activity.

  13. Determination and characterization of kernel biochemical composition and functional compounds of Persian walnut oil.

    PubMed

    Gharibzahedi, Seyed Mohammad Taghi; Mousavi, Seyed Mohammad; Hamedi, Manouchehr; Khodaiyan, Faramarz

    2014-01-01

    Kernel chemical composition and fatty acids profile of three walnut cultivars (Toyserkan, Chaboksar and Karaj) was analyzed. Some physicochemical properties, total phenolics content (TPC), ortho-diphenols content (ODC) and total tocopherol concentration (TTC) of extracted oils from the walnuts were also determined. The antioxidant activity of oil was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and β-carotene bleaching assays. The analysis of chemical composition revealed that protein and dietary fiber was highest in Toyserkan cultivar. Phosphorus was the most abundant element in the walnut kernels, followed by potassium, magnesium and calcium. The linoleic acid and linolenic contents ranged from 50.15% to 51.36% and 10.48% to 12.04%, respectively. Also, the results demonstrated that acid value, saponification value and viscosity of extracted oil had significantly varied between all cultivars. The extracted oil from Chaboksar cultivar illustrated more hydro peroxides and secondary products than those obtained from other cultivars. A positive correlation was found between Rancimat values and oleic acid content (r = 0.60), but considerably negative correlation with TTC (r = -0.81) and TPC (r = -0.92). The relationship between percentage of remaining DPPH radical and β-carotene of walnut oils showed high correlation among three selected cultivars (r = -0.94 to -0.97). PMID:24426045

  14. Anti-methicillin Resistant Staphylococcus aureus Compound Isolation from Halophilic Bacillus amyloliquefaciens MHB1 and Determination of Its Mode of Action Using Electron Microscope and Flow Cytometry Analysis.

    PubMed

    Jeyanthi, Venkadapathi; Velusamy, Palaniyandi

    2016-06-01

    The aim of this study was to purify, characterize and evaluate the antibacterial activity of bioactive compound against methicillin-resistant Staphylococcus aureus (MRSA). The anti-MRSA compound was produced by a halophilic bacterial strain designated as MHB1. The MHB1 strain exhibited 99 % similarity to Bacillus amyloliquefaciens based on 16S rRNA gene analysis. The culture conditions of Bacillus amyloliquefaciens MHB1 were optimized using nutritional and environmental parameters for enhanced anti-MRSA compound production. The pure bioactive compound was isolated using silica gel column chromatography and Semi-preparative High-performance liquid chromatography (Semi-preparative HPLC). The Thin layer chromatography, Fourier transform infrared spectroscopy and proton NMR ((1)H NMR) analysis indicated the phenolic nature of the compound. The molecular mass of the purified compound was 507 Da as revealed by Liquid chromatography-mass spectrometry (LC-MS) analysis. The compound inhibited the growth of MRSA with minimum inhibitory concentration (MIC) of 62.5 µg mL(-1). MRSA bacteria exposed to 4× MIC of the compound and the cell viability was determined using flow cytometric analysis. Scanning electron microscope and Transmission electron microscope analysis was used to determine the ultrastructural changes in bacteria. This is the first report on isolation of anti-MRSA compound from halophilic B. amyloliquefaciens MHB1 and could act as a promising biocontrol agent. PMID:27570306

  15. Composition of RF-sputtered refractory compounds determined by X-ray photoelectron spectroscopy

    NASA Technical Reports Server (NTRS)

    Wheeler, D. R.; Brainard, W. A.

    1978-01-01

    RF-sputtered coatings of CrB2, MoSi2, Mo2C, TiC, and MoS2 were examined by X-ray photoelectron spectroscopy (XPS). Data on stoichiometry, impurity content, and chemical bonding were obtained. The influences of sputtering target history, deposition time, RF power level, and substrate bias were studied. Significant deviations from stoichiometry and high oxide levels were related to target outgassing. The effect of substrate bias depended on the particular coating material studied.

  16. Sublethal effects of chronic exposure to an organochlorine compound on northern leopard frog (Rana pipiens) tadpoles.

    PubMed

    Glennemeler, K A; Denver, R J

    2001-01-01

    Global contamination with organochlorine compounds (OCs) has posed developmental and reproductive problems in wildlife worldwide. However, little is known about the impact of OCs or other pollutants on amphibians, despite mounting concerns about amphibian population declines and developmental deformities in the wild. Wildlife populations may be affected critically by sublethal impacts of anthropogenic disturbances, yet little research has focused on such effects in amphibians. In the current study, northern leopard frog (Rana pipiens) tadpoles were chronically exposed to a polychlorinated biphenyl (PCB) congener, 77-TCB, and effects on behavior, morphology, competitive performance, and corticosterone content were determined. R. pipiens activity levels and feeding rates were decreased by 77-TCB exposure, but morphology of mouthparts and body proportions were unaffected. 77-TCB enhanced growth and altered competitive interactions between R. pipiens and wood frog (Rana sylvatica) tadpoles. R. pipiens tadpoles exposed to 77-TCB showed decreased whole-body corticosterone content compared to controls both before and after injection with adrenocorticotropic hormone (ACTH). All of the factors examined in the current study play critical roles in tadpole development, growth, survivorship, and eventual reproductive success, suggesting negative population-level consequences for amphibians in PCB-contaminated habitats.

  17. Effect of intoxication with vanadium compounds on copper metabolism in the rat

    SciTech Connect

    Witkowska, D.; Oledzka, R.; Markowska, B.

    1988-02-01

    Vanadium is required in comparatively small quantities for normal growth and differentiation in all organisms. Whether the element is essential and what its precise function is remains difficult to ascertain because the reported evidence is inconclusive. Man's activities in petroleum and metallurgical refining have magnified naturally high concentrations of the metal in certain crude oils and ores. The adverse effects of human exposure to the combustion products of vanadium-bearing residual oils and to fumes and dusts in metallurgical refining have stimulated interest in vanadium toxicology. The mechanisms by which vanadium exerts its toxic effects are poorly understood, but interference with the normal kinetics and macromolecular binding of the body's other essential metals, such as Zn, Ca, Mg, Fe, Cu may play a significant role. The purpose of the present study was to determine the influence of intoxication with vanadium compounds (NaVO/sub 3/ and VOSO/sub 4/) on the intestinal transport of copper. Serum levels of copper and ceruloplasmin and copper content in the liver were also assayed.

  18. Infrared decontamination of oregano: effects on Bacillus cereus spores, water activity, color, and volatile compounds.

    PubMed

    Eliasson, Lovisa; Libander, Patrik; Lövenklev, Maria; Isaksson, Sven; Ahrné, Lilia

    2014-12-01

    Infrared (IR) heating, a novel technology for decontaminating oregano, was evaluated by investigating the reduction of inoculated Bacillus cereus spores and the effect on water activity (a(w)), color, and headspace volatile compounds after exposure to IR treatment. Conditioned oregano (a(w) 0.88) was IR-treated in a closed heating unit at 90 and 100 °C for holding times of 2 and 10 min, respectively. The most successful reduction in B. cereus spore numbers (5.6 log units) was achieved after a holding time of 10 min at 90 °C, while treatment at 100 °C for the same time resulted in a lower reduction efficiency (4.7 log units). The lower reduction at 100 °C was probably due to a reduced aw (aw 0.76) during IR treatment or possibly to the alteration or loss of volatile compounds possessing antimicrobial properties. The green color of oregano was only slightly affected, while the composition of volatile compounds was clearly altered by IR heating. However, two of the key aroma compounds, carvacrol and thymol, were only slightly affected, compared to the effect on the other studied compounds, indicating that the typical oregano aroma can likely be preserved. In conclusion, IR heating shows potential for the successful decontamination of oregano without severe alteration of its color or the key aroma compounds, carvacrol and thymol. PMID:25393824

  19. AMPK-dependent and independent effects of AICAR and compound C on T-cell responses

    PubMed Central

    Rao, Enyu; Zhang, Yuwen; Li, Qiang; Hao, Jiaqing; Egilmez, Nejat K.; Suttles, Jill; Li, Bing

    2016-01-01

    As a master metabolic sensor, AMP-activated protein kinase (AMPK) is involved in different fundamental cellular processes. Regulation of AMPK activity either by agonists (e.g., AICAR) or by antagonists (e.g., Compound C) has been widely employed to study the physiological functions of AMPK. However, mounting evidence indicates AMPK-independent effects for these chemicals and how they regulate immune cell functions remains largely unknown. Herein, using T cells from AMPK conditional knockout mice and their wild type littermates, we demonstrate that AICAR and Compound C can, indeed, activate or inhibit AMPK activity in T cells, respectively. Specifically, AICAR inhibits, but Compound C promotes, Ca2+-induced T cell death in an AMPK-dependent manner. In contrast, our data also demonstrate that AICAR and Compound C inhibit T cell activation and cytokine production in an AMPK-independent manner. Moreover, we find that the AMPK-independent activity of AICAR and Compound Cis mediated via the mTOR signaling pathway in activated T cells. Our results not only reveal the critical role of AMPK in regulating T cell survival and function, but also demonstrate AMPK-dependent and independent rolesof AICAR/Compound C in regulating T cell responses, thus suggesting a context-dependent effect of these “AMPK regulators”. PMID:27177226

  20. Infrared decontamination of oregano: effects on Bacillus cereus spores, water activity, color, and volatile compounds.

    PubMed

    Eliasson, Lovisa; Libander, Patrik; Lövenklev, Maria; Isaksson, Sven; Ahrné, Lilia

    2014-12-01

    Infrared (IR) heating, a novel technology for decontaminating oregano, was evaluated by investigating the reduction of inoculated Bacillus cereus spores and the effect on water activity (a(w)), color, and headspace volatile compounds after exposure to IR treatment. Conditioned oregano (a(w) 0.88) was IR-treated in a closed heating unit at 90 and 100 °C for holding times of 2 and 10 min, respectively. The most successful reduction in B. cereus spore numbers (5.6 log units) was achieved after a holding time of 10 min at 90 °C, while treatment at 100 °C for the same time resulted in a lower reduction efficiency (4.7 log units). The lower reduction at 100 °C was probably due to a reduced aw (aw 0.76) during IR treatment or possibly to the alteration or loss of volatile compounds possessing antimicrobial properties. The green color of oregano was only slightly affected, while the composition of volatile compounds was clearly altered by IR heating. However, two of the key aroma compounds, carvacrol and thymol, were only slightly affected, compared to the effect on the other studied compounds, indicating that the typical oregano aroma can likely be preserved. In conclusion, IR heating shows potential for the successful decontamination of oregano without severe alteration of its color or the key aroma compounds, carvacrol and thymol.

  1. Inhibitory effect of compounds from Zingiberaceae species on human platelet aggregation.

    PubMed

    Jantan, I; Raweh, S M; Sirat, H M; Jamil, S; Mohd Yasin, Y H; Jalil, J; Jamal, J A

    2008-04-01

    Twelve compounds isolated from Alpinia mutica Roxb., Kaempferia rotunda Linn., Curcuma xanthorhiza Roxb., Curcuma aromatica Valeton and Zingiber zerumbet Smith (Family: Zingiberaceae) and three synthesized derivatives of xanthorrhizol were evaluated for their ability to inhibit arachidonic acid- (AA), collagen- and ADP-induced platelet aggregation in human whole blood. Antiplatelet activity of the compounds was measured in vitro by the Chrono Log whole blood aggregometer using an electrical impedance method. Among the compounds tested, curcumin from C. aromatica, cardamonin, pinocembrine and 5,6-dehydrokawain from A. mutica and 3-deacetylcrotepoxide from K. rotunda showed strong inhibition on platelet aggregation induced by AA with IC(50) values of less than 84 microM. Curcumin was the most effective antiplatelet compound as it inhibited AA-, collagen- and ADP-induced platelet aggregation with IC(50) values of 37.5, 60.9 and 45.7 microM, respectively.

  2. Word-Superiority Effect as a Function of Semantic Transparency of Chinese Bimorphemic Compound Words

    ERIC Educational Resources Information Center

    Mok, Leh Woon

    2009-01-01

    The word-superiority effect (WSE) describes the superior recognition of word constituents in a word, as opposed to a non-word, context. In this study, the WSE was used as a diagnostic tool to examine the modulatory effect of word semantic transparency on the degree to which Chinese bimorphemic compound words are lexically represented as unitised…

  3. Inverse barocaloric effect in the giant magnetocaloric La-Fe-Si-Co compound.

    PubMed

    Mañosa, Lluís; González-Alonso, David; Planes, Antoni; Barrio, Maria; Tamarit, Josep-Lluís; Titov, Ivan S; Acet, Mehmet; Bhattacharyya, Amitava; Majumdar, Subham

    2011-12-20

    Application of hydrostatic pressure under adiabatic conditions causes a change in temperature in any substance. This effect is known as the barocaloric effect and the vast majority of materials heat up when adiabatically squeezed, and they cool down when pressure is released (conventional barocaloric effect). There are, however, materials exhibiting an inverse barocaloric effect: they cool when pressure is applied, and they warm when it is released. Materials exhibiting the inverse barocaloric effect are rather uncommon. Here we report an inverse barocaloric effect in the intermetallic compound La-Fe-Co-Si, which is one of the most promising candidates for magnetic refrigeration through its giant magnetocaloric effect. We have found that application of a pressure of only 1 kbar causes a temperature change of about 1.5 K. This value is larger than the magnetocaloric effect in this compound for magnetic fields that are available with permanent magnets.

  4. Effect of nitrogen source on biomass and bioactive compound production in submerged cultures of Eleutherococcus koreanum Nakai adventitious roots.

    PubMed

    Lee, Eun-Jung; Paek, Kee-Yoeup

    2012-01-01

    Ammonium to nitrate ratios of 0:30, 5:25, 10:20, 15:15, 20:10, 25:5, and 30:0 mM were tested to determine the optimal NH(4)(+) :NO(3)(-) ratio for improving biomass and bioactive compound production in Eleutherococcus koreanum Nakai adventitious roots using 3-L bulb-type bubble bioreactors. A high ammonium nitrogen ratio had a negative effect on root growth, and the highest fresh and dry weights were obtained when NH(4)(+):NO(3)(-) ratios were 5:25 and 10:20 (mM) after 5 weeks of culture. Although the total production of eleutherosides B and E was slightly higher at the 10:20 ratio than at the 5:25 ratio (NH(4)(+):NO(3)(-)), we proposed that the optimal NH(4)(+):NO(3)(-) ratio was 5:25 mM. This ratio achieved both the highest total production of five target bioactive compounds (eleutherosides B and E, chlorogenic acid, total phenolics, and flavonoids) and the highest root biomass. Furthermore, increasing NH(4)(+):NO(3)(-) ratios to 10:20 decreased pH in the medium, interrupted the absorption of essential minerals from the culture medium, and resulted in low biomass and increased relative oxidative stress levels, which were evaluated by determining 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Therefore, nitrate rather than ammonium nitrogen was more essential not for only biomass production but also for bioactive compound production in E. koreanum adventitious root cultures. The optimal nitrogen source ratio produced 5.63 g L(-1) of biomass and 24.41 mg of the five total bioactive compounds per gram of biomass (dry weight basis). The development of such in vitro culture technology will benefit the pilot-scale production of E. koreanum-based bioactive compounds for commercialization.

  5. Compelling Issues Compounding the Understanding of Low Dose Radiation Effects: But Do They Matter?

    PubMed

    Morgan, William F

    2016-03-01

    Recent advances in low dose radiation research have raised a number of compelling issues that have compounded the understanding of low dose radiation effects. Here some of them are outlined: the linear no-threshold model for predicting effects at low radiation doses, dose rate effectiveness factor, attributability, and public perception of low dose radiation effects. The impact of changes in any of these hotly debated issues on radiation protection is considered.

  6. Diagnostic determination of melamine and related compounds in kidney tissue by liquid chromatography/tandem mass spectrometry.

    PubMed

    Filigenzi, Michael S; Puschner, Birgit; Aston, Linda S; Poppenga, Robert H

    2008-09-10

    In 2007, it was determined that melamine, ammeline, ammelide, and cyanuric acid (abbreviated as MARC for melamine and related contaminants) had been added to wheat gluten and rice protein that were subsequently incorporated into pet food. The consumption of food tainted by MARC compounds was implicated in numerous instances of renal failure in cats and dogs. A method for the analysis of MARC compounds in kidney tissue using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) has been developed. MARC analytes were extracted by homogenization of kidney tissue in 50/40/10 acetonitrile/water/diethylamine. The homogenate was centrifuged, and an aliquot of supernatant was diluted with acetonitrile, concentrated, and fortified with a stable isotope-labeled analogue of melamine. Analytes were detected using atmospheric pressure chemical ionization and multiple reaction monitoring. Quantitation of positive samples was performed using the internal standard method and five-point calibration curves ranging between 50 and 1000 ng/mL of each analyte. The method was validated by analysis of replicate kidney tissue samples fortified with the individual analytes and by analysis of kidney samples fortified with melamine cyanurate powder at two different concentrations. This method was successfully used for routine postmortem diagnosis of melamine toxicosis in animals. Melamine was also detected by this method in paraffin-embedded tissue from animals suspected to have died of melamine toxicosis. PMID:18652475

  7. Simultaneous determination of bioactive compounds in Piper nigrum L. and a species comparison study using HPLC-PDA.

    PubMed

    Rao, Vidadala Rama Subba; Raju, Sagi Satyanarayana; Sarma, Vanka Umamaheswara; Sabine, Fouriner; Babu, Kothapalli Hari; Babu, Katragadda Suresh; Rao, Janaswamy Madhusudana

    2011-08-01

    Piper nigrum L. is a traditional medicine widely used in India for illnesses such as constipation, diarrhoea, earache, gangrene, heart disease, hernia, hoarseness, indigestion, insect bites, insomnia, joint pain, liver problems, lung disease, oral abscesses, sunburn, tooth decay and toothaches. In this study, six bioactive compounds, namely piperine (1), pellitorine (2), guineensine (3), pipnoohine (4), trichostachine (5) and piperonal (6) were quantified in different extracts of P. nigrum L. and compared with those of P. longum L. and P. chaba Hunter. To evaluate the quality of P. nigrum, a simple, accurate and precise HPLC-PDA method was developed for the simultaneous determination of the above-mentioned six compounds. The separation was achieved by Phenomenex Luna RP C(18) column (150 × 4.6 mm, 5 µm, Phenomenex Inc, CA, USA) with a binary gradient solvent system of water-acetonitrile, at a flow rate of 1.0 mL min(-1) and detected at 210, 232, 262 and 343 nm. All six calibration curves showed good linearity (R (2) > 0.9966). The method was reproducible with intra- and inter-day variations of less than 2% and 5%, respectively. The results demonstrated that this method is simple, reliable and suitable for the quality control of these plants.

  8. Direct determination and speciation of mercury compounds in environmental and biological samples by carbon bed atomic absorption spectroscopy

    SciTech Connect

    Skelly, E.M.

    1982-01-01

    A method was developed for the direct determination of mercury in water and biological samples using a unique carbon bed atomizer for atomic absorption spectroscopy. The method avoided sources of error such as loss of volatile mercury during sample digestion and contamination of samples through added reagents by eliminating sample pretreatment steps. The design of the atomizer allowed use of the 184.9 nm mercury resonance line in the vacuum ultraviolet region, which increased sensitivity over the commonly used spin-forbidden 253.7 nm line. The carbon bed atomizer method was applied to a study of mercury concentrations in water, hair, sweat, urine, blood, breath and saliva samples from a non-occupationally exposed population. Data were collected on the average concentration, the range and distribution of mercury in the samples. Data were also collected illustrating individual variations in mercury concentrations with time. Concentrations of mercury found were significantly higher than values reported in the literature for a ''normal'' population. This is attributed to the increased accuracy gained by eliminating pretreatment steps and increasing atomization efficiency. Absorption traces were obtained for various solutions of pure and complexed mercury compounds. Absorption traces of biological fluids were also obtained. Differences were observed in the absorption-temperatures traces of various compounds. The utility of this technique for studying complexation was demonstrated.

  9. Determination of volatile organic compounds in water using ultrasound-assisted emulsification microextraction followed by gas chromatography.

    PubMed

    Leong, Mei-I; Huang, Shang-Da

    2012-03-01

    Volatile organic compounds (VOCs) are toxic compounds in the air, water and land. In the proposed method, ultrasound-assisted emulsification microextraction (USAEME) combined with gas chromatography-mass spectrometry (GC-MS) has been developed for the extraction and determination of eight VOCs in water samples. The influence of each experimental parameter of this method (the type of extraction solvent, volume of extraction solvent, salt addition, sonication time and extraction temperature) was optimized. The procedure for USAEME was as follows: 15 μL of 1-bromooctane was used as the extraction solvent; 10 mL sample solution in a centrifuge tube with a cover was then placed in an ultrasonic water bath for 3 min. After centrifugation, 2 μL of the settled 1-bromooctane extract was injected into the GC-MS for further analysis. The optimized results indicated that the linear range is 0.1-100.0 μg/L and the limits of detection (LODs) are 0.033-0.092 μg/L for the eight analytes. The relative standard deviations (RSD), enrichment factors (EFs) and relative recoveries (RR) of the method when used on lake water samples were 2.8-9.5, 96-284 and 83-110%. The performance of the proposed method was gauged by analyzing samples of tap water, lake water and river water samples. PMID:22271628

  10. Determination of the solubility of low volatility liquid organic compounds in water using volatile-tracer assisted headspace gas chromatography.

    PubMed

    Zhang, Shu-Xin; Chai, Xin-Sheng; Barnes, Donald G

    2016-02-26

    This study reports a new headspace gas chromatographic method (HS-GC) for the determination of water solubility of low volatility liquid organic compounds (LVLOs). The HS-GC analysis was performed on a set of aqueous solutions containing a range of concentrations of toluene-spiked (as a tracer) LVLOs, from under-saturation to over-saturation. A plot of the toluene tracer GC signal vs. the concentration of the LVLO results in two lines of different slopes that intersect at the concentration corresponding to the compound's solubility in water. The results showed that the HS-GC method has good precision (RSD <6.3%) and good accuracy, in which the relative deference between the data measured by the HS-GC method and the reference method were within 6.0%. The HS-GC method is simple and particularly suitable for measuring the solubility of LVLOs at elevated temperatures. This approach should be of special interest to those concerned about the impact of the presence of low-volatility organic liquids in waters of environmental and biological systems. PMID:26850316

  11. Determination of the solubility of low volatility liquid organic compounds in water using volatile-tracer assisted headspace gas chromatography.

    PubMed

    Zhang, Shu-Xin; Chai, Xin-Sheng; Barnes, Donald G

    2016-02-26

    This study reports a new headspace gas chromatographic method (HS-GC) for the determination of water solubility of low volatility liquid organic compounds (LVLOs). The HS-GC analysis was performed on a set of aqueous solutions containing a range of concentrations of toluene-spiked (as a tracer) LVLOs, from under-saturation to over-saturation. A plot of the toluene tracer GC signal vs. the concentration of the LVLO results in two lines of different slopes that intersect at the concentration corresponding to the compound's solubility in water. The results showed that the HS-GC method has good precision (RSD <6.3%) and good accuracy, in which the relative deference between the data measured by the HS-GC method and the reference method were within 6.0%. The HS-GC method is simple and particularly suitable for measuring the solubility of LVLOs at elevated temperatures. This approach should be of special interest to those concerned about the impact of the presence of low-volatility organic liquids in waters of environmental and biological systems.

  12. Effect of charge trapping on effective carrier lifetime in compound semiconductors: High resistivity CdZnTe

    SciTech Connect

    Kamieniecki, Emil

    2014-11-21

    The dominant problem limiting the energy resolution of compound semiconductor based radiation detectors is the trapping of charge carriers. The charge trapping affects energy resolution through the carrier lifetime more than through the mobility. Conventionally, the effective carrier lifetime is determined using a 2-step process based on measurement of the mobility-lifetime product (μτ) and determining drift mobility using time-of-flight measurements. This approach requires fabrication of contacts on the sample. A new RF-based pulse rise-time method, which replaces this 2-step process with a single non-contact direct measurement, is discussed. The application of the RF method is illustrated with high-resistivity detector-grade CdZnTe crystals. The carrier lifetime in the measured CdZnTe, depending on the quality of the crystals, was between about 5 μs and 8 μs. These values are in good agreement with the results obtained using conventional 2-step approach. While the effective carrier lifetime determined from the initial portion of the photoresponse transient combines both recombination and trapping in a manner similar to the conventional 2-step approach, both the conventional and the non-contact RF methods offer only indirect evaluation of the effect of charge trapping in the semiconductors used in radiation detectors. Since degradation of detector resolution is associated not with trapping but essentially with detrapping of carriers, and, in particular, detrapping of holes in n-type semiconductors, it is concluded that evaluation of recombination and detrapping during photoresponse decay is better suited for evaluation of compound semiconductors used in radiation detectors. Furthermore, based on previously reported data, it is concluded that photoresponse decay in high resistivity CdZnTe at room temperature is dominated by detrapping of carriers from the states associated with one type of point defect and by recombination of carriers at one type of

  13. Determining malaria effects in rural Colombia.

    PubMed

    Bonilla, E; Rodriguez, A

    1993-11-01

    Good health is an integral component of the quality of human life, a prerequisite for developing human potential and an important determinant of economic development. When a person is ill from a tropical disease in an agricultural economy, a complex interaction between the individual's welfare and the family's welfare is set in motion. So complex are these interactions that few empirical studies exist on this subject and even where they do, empirical quantification of these interactions and economic losses places the analyst in the minefield of valuing time, ability and contribution to economic welfare. Placing monetary values on these commodities is always a little unsatisfactory since dollar values do not adequately reflect the nature of the losses. Secondly, the ill person's struggle to minimize the economic effects of disease on family income will mask its true impact; thirdly, tropical diseases disproportionately affect low-income groups and therefore measuring the income effects of disease amongst these groups will only reach at the earnings effect, and underestimate the economic implications of tropical disease control. Despite these difficulties, quantification of the economic impact of disease is important from a public health point of view. This study is an attempt at such a task, and focuses on the intra-familial struggle to minimize economic losses due to malaria. Using a case-control approach, time-losses and labour reallocations within the household are examined in an attempt to understand the economic consequences of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Development and validation of an high-performance liquid chromatography-diode array detector method for the simultaneous determination of six phenolic compounds in abnormal savda munziq decoction

    PubMed Central

    Tian, Shuge; Liu, Wenxian; Liu, Feng; Zhang, Xuejia; Upur, Halmuart

    2015-01-01

    Aims: Given the high-effectiveness and low-toxicity of abnormal savda munziq (ASMQ), its herbal formulation has long been used in traditional Uyghur medicine to treat complex diseases, such as cancer, diabetes, and cardiovascular diseases. Settings and Design: ASMQ decoction by reversed-phase high-performance liquid chromatography coupled with a diode array detector was successfully developed for the simultaneous quality assessment of gallic acid, protocatechuic acid, caffeic acid, rutin, rosmarinic acid, and luteolin. The six phenolic compounds were separated on an Agilent TC-C18 reversed-phase analytical column (4.6 × 250 mm, 5 μm) by gradient elution using 0.3% aqueous formic acid (v/v) and 0.3% methanol formic acid (v/v) at 1.0 mL/min. Materials and Methods: The plant material was separately ground and mixed at the following ratios (10): Cordia dichotoma (10.6), Anchusa italic (10.6), Euphorbia humifusa (4.9), Adiantum capillus-veneris (4.9), Ziziphus jujube (4.9), Glycyrrhiza uralensis (7.1), Foeniculum vulgare (4.9), Lavandula angustifolia (4.9), Dracocephalum moldavica L. (4.9), and Alhagi pseudoalhagi (42.3). Statistical Analysis Used: The precisions of all six compounds were <0.60%, and the average recoveries ranged from 99.39% to 104.85%. Highly significant linear correlations were found between component concentrations and specific chromatographic peak areas (R2 > 0.999). Results: The proposed method was successfully applied to determine the levels of six active components in ASMQ. Conclusions: Given the simplicity, precision, specificity, and sensitivity of the method, it can be utilized as a quality control approach to simultaneously determining the six phenolic compounds in AMSQ. PMID:25709227

  15. [Determination of six main components in compound theophylline tablet by convolution curve method after prior separation by column partition chromatography

    NASA Technical Reports Server (NTRS)

    Zhang, S. Y.; Wang, G. F.; Wu, Y. T.; Baldwin, K. M. (Principal Investigator)

    1993-01-01

    On a partition chromatographic column in which the support is Kieselguhr and the stationary phase is sulfuric acid solution (2 mol/L), three components of compound theophylline tablet were simultaneously eluted by chloroform and three other components were simultaneously eluted by ammonia-saturated chloroform. The two mixtures were determined by computer-aided convolution curve method separately. The corresponding average recovery and relative standard deviation of the six components were as follows: 101.6, 1.46% for caffeine; 99.7, 0.10% for phenacetin; 100.9, 1.31% for phenobarbitone; 100.2, 0.81% for theophylline; 99.9, 0.81% for theobromine and 100.8, 0.48% for aminopyrine.

  16. Development of an analytical method for the determination of organic compounds in fossil-fuel aqueous leachates

    SciTech Connect

    White, C.M.; Avery, M.; Blanton, W.; Hilpert, L.; Jackson, L.; Junk, G.; Maskarinec, M.; Paule, R.C.; Raphaelian, L.; Richard, J.

    1983-10-01

    An analytical method has been developed for analysis of organic compounds in aqueous leachates of fossil fuel solid wastes. The method has been evaluated using two synthetic leachates as well as bulk and small-scale leachates of SRC-II vacuum still bottoms at the participating laboratories. Under the conditions of these tests, the method worked well for most analytes; however, n-hexanoic acid, 4-aminobiphenyl, 1,4-naphtoquinone, and 1-nephthylamine were not determined accurately or precisely by the method. Other analytes of interest are benzanthracene, o-cresol, phenanthrene, carbazole, naphthalene, phenol, n-tetradecane, 2-naphthol, dibenzothiophene, quinoline, acenaphthylene, 2-picoline, fluoranthrene, 2,3,4,5-tetrachlorobiphenyl (standard), 2-fluorophenol (standard), n-octacosane (standard), and azulene (standard). 7 references, 22 figures, 26 tables.

  17. Determination of quaternary ammonium compounds by potentiometric titration with an ionic surfactant electrode: single-laboratory validation.

    PubMed

    Price, Randi; Wan, Ping

    2010-01-01

    A potentiometric titration for determining the quaternary ammonium compounds (QAC) commonly found in antimicrobial products was validated by a single laboratory. Traditionally, QACs were determined by using a biphasic (chloroform and water) manual titration procedure. Because of safety considerations regarding chloroform, as well as the subjectivity of color indicator-based manual titration determinations, an automatic potentiometric titration procedure was tested with quaternary nitrogen product formulations. By using the Metrohm Titrando system coupled with an ionic surfactant electrode and an Ag/AgCl reference electrode, titrations were performed with various QAC-containing formulation products/matrixes; a standard sodium lauryl sulfate solution was used as the titrant. Results for the products tested are sufficiently reproducible and accurate for the purpose of regulatory product enforcement. The robustness of the method was measured by varying pH levels, as well as by comparing buffered versus unbuffered titration systems. A quantitation range of 1-1000 ppm quaternary nitrogen was established. Eight commercially available antimicrobial products covering a variety of matrixes were assayed; the results obtained were comparable to those obtained by the manual titration method. Recoveries of 94 to 104% were obtained for spiked samples.

  18. Simultaneous Determination of Five Alkaloid Compounds in a Drug Based on a Hydrophilic Monolithic Column by Capillary Electrochromatography.

    PubMed

    Chen, Zongbao; Ye, Qing; Liu, Linghai; Dong, Hongxia

    2016-01-01

    A novel capillary electrochromatography (CEC) method was developed by using a hydrophilic monolithic column for the simultaneous determination of five alkaloids in a drug. The monolithic stationary phase was first prepared via in situ polymerization of acrylamide (AM), glycidyl methacrylate (GMA), N,N'-methylenebisacrylamide (MBA) and 2-acrylamido-2-methyl-1-propane-sulfonic acid (AMPS) in a ternary porogen solvent system consisting of cyclohexanol, dodecanol and toluene. The obtained monolithic stationary phase was subsequently modified by 0.1 mol/L ammonia water for opening epoxide groups of GMA. The separation performance and efficiency of the resulting monolithic column were investigated by the use of five compounds (thiourea, aniline, naphthylamine, diphenylamine and dimethyl acetamide) by CEC. The optimized monolithic column has obtained high column efficiencies with 74,000-121,000 theoretical plates/m. Finally, the prepared monolithic column was used to separate and determine five alkaloids (piperine, nuciferine, kukoline, berberine and tetrandrine) using CEC. Under the conditions of acetonitrile/10 mM phosphate buffer solution (65/35, v/v, pH 8.5) and 15 kV applied voltage, the baseline separation of five alkaloids was achieved. The proposed method has been successfully applied to the determination of berberine in a tablet sample. The percentage of recovery of spiked tablet samples ranged from 93.4 to 108.0% with relative standard deviations (RSDs) <9.20%. PMID:26187925

  19. Determination of quaternary ammonium compounds by potentiometric titration with an ionic surfactant electrode: single-laboratory validation.

    PubMed

    Price, Randi; Wan, Ping

    2010-01-01

    A potentiometric titration for determining the quaternary ammonium compounds (QAC) commonly found in antimicrobial products was validated by a single laboratory. Traditionally, QACs were determined by using a biphasic (chloroform and water) manual titration procedure. Because of safety considerations regarding chloroform, as well as the subjectivity of color indicator-based manual titration determinations, an automatic potentiometric titration procedure was tested with quaternary nitrogen product formulations. By using the Metrohm Titrando system coupled with an ionic surfactant electrode and an Ag/AgCl reference electrode, titrations were performed with various QAC-containing formulation products/matrixes; a standard sodium lauryl sulfate solution was used as the titrant. Results for the products tested are sufficiently reproducible and accurate for the purpose of regulatory product enforcement. The robustness of the method was measured by varying pH levels, as well as by comparing buffered versus unbuffered titration systems. A quantitation range of 1-1000 ppm quaternary nitrogen was established. Eight commercially available antimicrobial products covering a variety of matrixes were assayed; the results obtained were comparable to those obtained by the manual titration method. Recoveries of 94 to 104% were obtained for spiked samples. PMID:21140668

  20. A screening of multiple classes of pharmaceutical compounds for effect on preadult salmon lice Lepeophtheirus salmonis.

    PubMed

    Aaen, S M; Horsberg, T E

    2016-10-01

    The salmon louse, Lepeophtheirus salmonis Krøyer, is the major obstacle facing a sustainable future for farmers of salmonids in the North Atlantic Ocean. Medicinal compounds have been the most utilized tool to prevent salmon lice infestation; however, the active compounds have become less effective or considered environmentally unfriendly in the past years. Novel medicinal compounds are thus highly desired. In two experiment series, 26 medicinal compounds were screened for their efficacy against salmon lice, in a 30-min exposure and 24-h exposure, respectively. Pyriprole, imidacloprid, cartap and spinetoram were effective at 50 mg L(-1) in the short-time exposure. In the 24-h exposure, pyriprole, propoxur, cartap, imidacloprid, fenoxycarb, pyriproxyfen, nitenpyram, spinetoram, spiromesifen and diflubenzuron induced a high level of immobilization at 5 mg L(-1) . The EC50 values of the effective compounds were calculated in further titration studies for both exposure periods. Several physiological and biochemical pathways were discovered as possible targets for medicinal intervention against the salmon louse. PMID:27037538

  1. Effects of bulking agent addition on odorous compounds emissions during composting of OFMSW.

    PubMed

    Shao, Li-Ming; Zhang, Chun-Yan; Wu, Duo; Lü, Fan; Li, Tian-Shui; He, Pin-Jing

    2014-08-01

    The effects of rice straw addition level on odorous compounds emissions in a pilot-scale organic fraction of municipal solid waste (OFMSW) composting plant were investigated. The cumulative odorous compounds emissions occurred in a descending order of 40.22, 28.71 and 27.83 mg/dry kg of OFMSW for piles with rice straw addition level at ratio of 1:10, 2:10 and 3:10 (mixing ratio of rice straw to OFMSW on a wet basis), respectively. The mixing ratio of rice straw to OFMSW had a statistically significant effect on the reduction of malodorous sulfur compounds emissions, which had no statistically significant effect on the reduction of VFAs, alcohols, aldehydes, ketones, aromatics and ammonia emissions during composting, respectively. The cumulative emissions of malodorous sulfur compounds from piles with the increasing rice straw addition level were 1.17, 1.08 and 0.88 mg/dry kg of OFMSW, respectively. The optimal mixing ratio of rice straw to OFMSW was 1:5. Using this addition level, the cumulative malodorous sulfur compounds emissions based on the organic matter degradation were the lowest during composting of OFMSW. PMID:24820662

  2. A screening of multiple classes of pharmaceutical compounds for effect on preadult salmon lice Lepeophtheirus salmonis.

    PubMed

    Aaen, S M; Horsberg, T E

    2016-10-01

    The salmon louse, Lepeophtheirus salmonis Krøyer, is the major obstacle facing a sustainable future for farmers of salmonids in the North Atlantic Ocean. Medicinal compounds have been the most utilized tool to prevent salmon lice infestation; however, the active compounds have become less effective or considered environmentally unfriendly in the past years. Novel medicinal compounds are thus highly desired. In two experiment series, 26 medicinal compounds were screened for their efficacy against salmon lice, in a 30-min exposure and 24-h exposure, respectively. Pyriprole, imidacloprid, cartap and spinetoram were effective at 50 mg L(-1) in the short-time exposure. In the 24-h exposure, pyriprole, propoxur, cartap, imidacloprid, fenoxycarb, pyriproxyfen, nitenpyram, spinetoram, spiromesifen and diflubenzuron induced a high level of immobilization at 5 mg L(-1) . The EC50 values of the effective compounds were calculated in further titration studies for both exposure periods. Several physiological and biochemical pathways were discovered as possible targets for medicinal intervention against the salmon louse.

  3. Protective effects of novel organic selenium compounds against oxidative stress in the nematode Caenorhabditis elegans

    PubMed Central

    Stefanello, Sílvio Terra; Gubert, Priscila; Puntel, Bruna; Mizdal, Caren Rigon; de Campos, Marli Matiko Anraku; Salman, Syed M.; Dornelles, Luciano; Avila, Daiana Silva; Aschner, Michael; Soares, Félix Alexandre Antunes

    2015-01-01

    Organic selenium compounds possess numerous biological properties, including antioxidant activity. Yet, the high toxicity of some of them, such as diphenyl diselenide (DPDS), is a limiting factor in their current usage. Accordingly, we tested four novel organic selenium compounds in the non-parasite nematode Caenorhabditis elegans and compared their efficacy to DPDS. The novel organic selenium compounds are β-selenoamines (1-phenyl-3-(p-tolylselanyl)propan-2-amine (C1) and 1-(2-methoxyphenylselanyl)-3-phenylpropan-2-amine (C2) and analogs of DPDS (1,2-bis (2-methoxyphenyl) diselenide (C3) and 1,2-bisp-tolyldiselenide (C4). Synchronized worms at the L4 larval stage were exposed for one hour in M9 buffer to these compounds. Oxidative stress conditions were induced by juglone (200 μM) and heat shock (35 °C). Moreover, we evaluated Caenorhabditis elegans behavior, GST-4::GFP (glutathione S-transferase) expression and the activity of acetylcholinesterase (AChE). All tested compounds efficiently restored viability in juglone stressed worms. However, DPDS, C2, C3 and C4 significantly decreased the defecation cycle time. Juglone-induced GST-4::GFP expression was not attenuated in worms pretreated with the novel compounds, except with C2. Finally, AChE activity was reduced by DPDS, C2, C3 and C4. To our knowledge, this is study firstly showed the effects of C1, C2, C3 and C4 selenium-derived compounds in Caenorhabditis elegans. Low toxic effects were noted, except for reduction in the defecation cycle, which is likely associated with AChE inhibition. The juglone-induced stress (reduced viability) was fully reversed by compounds to control animal levels. C2 was also efficient in reducing the juglone-induced GST-4::GFP expression, suggesting the latter may mediate the stress induced by this compound. Future studies could be profitably directed at addressing additional molecular mechanisms that mediate the protective effects of these novel organic selenium compounds. PMID

  4. Effect of physiological harvest stages on the composition of bioactive compounds in Cavendish bananas.

    PubMed

    Bruno Bonnet, Christelle; Hubert, Olivier; Mbeguie-A-Mbeguie, Didier; Pallet, Dominique; Hiol, Abel; Reynes, Max; Poucheret, Patrick

    2013-04-01

    The combined influence of maturation, ripening, and climate on the profile of bioactive compounds was studied in banana (Musa acuminata, AAA, Cavendish, cv. Grande Naine). Their bioactive compounds were determined by the Folin-Ciocalteu assay and high-performance thin layer chromatographic (HPTLC) method. The polyphenol content of bananas harvested after 400 degree days remained unchanged during ripening, while bananas harvested after 600 and 900 degree days exhibited a significant polyphenol increase. Although dopamine was the polyphenol with the highest concentration in banana peels during the green developmental stage and ripening, its kinetics differed from the total polyphenol profile. Our results showed that this matrix of choice (maturation, ripening, and climate) may allow selection of the banana (M. acuminata, AAA, Cavendish, cv. Grande Naine) status that will produce optimal concentrations of identified compounds with human health relevance. PMID:23549844

  5. Effect of physiological harvest stages on the composition of bioactive compounds in Cavendish bananas.

    PubMed

    Bruno Bonnet, Christelle; Hubert, Olivier; Mbeguie-A-Mbeguie, Didier; Pallet, Dominique; Hiol, Abel; Reynes, Max; Poucheret, Patrick

    2013-04-01

    The combined influence of maturation, ripening, and climate on the profile of bioactive compounds was studied in banana (Musa acuminata, AAA, Cavendish, cv. Grande Naine). Their bioactive compounds were determined by the Folin-Ciocalteu assay and high-performance thin layer chromatographic (HPTLC) method. The polyphenol content of bananas harvested after 400 degree days remained unchanged during ripening, while bananas harvested after 600 and 900 degree days exhibited a significant polyphenol increase. Although dopamine was the polyphenol with the highest concentration in banana peels during the green developmental stage and ripening, its kinetics differed from the total polyphenol profile. Our results showed that this matrix of choice (maturation, ripening, and climate) may allow selection of the banana (M. acuminata, AAA, Cavendish, cv. Grande Naine) status that will produce optimal concentrations of identified compounds with human health relevance.

  6. Effect of physiological harvest stages on the composition of bioactive compounds in Cavendish bananas*

    PubMed Central

    Bruno Bonnet, Christelle; Hubert, Olivier; Mbeguie-A-Mbeguie, Didier; Pallet, Dominique; Hiol, Abel; Reynes, Max; Poucheret, Patrick

    2013-01-01

    The combined influence of maturation, ripening, and climate on the profile of bioactive compounds was studied in banana (Musa acuminata, AAA, Cavendish, cv. Grande Naine). Their bioactive compounds were determined by the Folin-Ciocalteu assay and high-performance thin layer chromatographic (HPTLC) method. The polyphenol content of bananas harvested after 400 degree days remained unchanged during ripening, while bananas harvested after 600 and 900 degree days exhibited a significant polyphenol increase. Although dopamine was the polyphenol with the highest concentration in banana peels during the green developmental stage and ripening, its kinetics differed from the total polyphenol profile. Our results showed that this matrix of choice (maturation, ripening, and climate) may allow selection of the banana (M. acuminata, AAA, Cavendish, cv. Grande Naine) status that will produce optimal concentrations of identified compounds with human health relevance. PMID:23549844

  7. Improving the accuracy of carbon-to-hydrogen ratio determination for P, N, S, O, Cl, and Br-containing organic compounds using atomic emission detection.

    PubMed

    Chernetsova, Elena S; Revelsky, Alexander I; Durst, Dupont; Sobolevsky, Tim G; Revelsky, Igor A

    2005-05-01

    The objective of this work was to investigate the dependence of atomic emission detector C and H response on microwave-induced plasma conditions and to improve the accuracy of carbon-to-hydrogen ratio determination for trialkylphosphates, herbicides, chlorophenols, and sulfur-containing organic compounds. Compounds which differed structurally from the analytes were used as reference compounds. It was found that when the oxygen concentration in the helium was the maximum for the instrument (9%) relative errors in carbon-to-hydrogen ratio determination were 3-8%, irrespective of analyte and reference compound structure, whereas when working in the mode of operation recommended by the manufacturer of the instrument (1.5% oxygen in helium) the respective errors were 10-20% or higher. This improvement in the accuracy of carbon-to-hydrogen ratio determination was accompanied by a factor of ten decrease in sensitivity. PMID:15688154

  8. Effects of an inorganic and two new organic compounds of selenium on morphologic blood elements and antioxidant status in mice.

    PubMed

    Musik, Irena; Kozioł-Montewka, Maria; Pasternak, Kazimierz; Toś-Luty, Sabina; Tokarska, Małgorzata

    2003-01-01

    Two organic compounds, 4-(o-tolilo-)-selenosemicarbazide of p-chlorobenzoic acid and 3-(p-chlorobenzoylamino-)-2-(o-tolylimino-)-4-phenyl-4-selenazoline were compared to the effects of the supplementation with inorganic Na2SeO3. Studies were carried out in four groups consisting of 10 female mice each of SWISS strain. Three of them were supplemented with different selenium formula at the dose of 10(-3) mg Se per g over the period of 10 day. The blood samples were collected to heparinized test tubes; the red blood and white blood count, hematocrit and haemoglobin concentration were studied. The influence of selenium compounds on phagocytosis and NBT test was determined.

  9. Effect of thiol compounds and flavins on mercury and organomercurial degrading enzymes in mercury resistant aquatic bacteria

    SciTech Connect

    Pahan, K.; Ray, S.; Gachhui, R.; Chaudhuri, J.; Mandal, A. )

    1990-02-01

    Plasmid-determined mercuric and organomercurial resistance in microorganisms has been studied by several workers. Mercury reductase, catalyzing the reduction of mercury depends on sulfhydryl compounds. Organomercurial lyase that catalyzes the splitting of C-Hg linkages also needs thiol compounds for its activity. Until recently, no study has been reported on thiol specificity of these enzymes from various sources. In the present study, the authors report on enzymatic volatilization of HgCl{sub 2} by fourteen Hg-resistant bacterial strains. They have also studied thiol specificity of Hg-reductases and organomercurial lyases isolated from the above bacterial species. Hg-reductase is known to have FAD-moiety which stimulates enzyme activity whereas FMN and riboflavin are ineffective in this regard. The effect of flavins, namely FAD, FMN and riboflavin, on Hg-reductase and organomercurial lyase activity is also reported here.

  10. Kinetic Cell-based Morphological Screening: Prediction of Mechanism of Compound Action and Off-Target Effects

    PubMed Central

    Abassi, Yama A.; Xi, Biao; Zhang, Wenfu; Ye, Peifang; Kirstein, Shelli L.; Gaylord, Michelle R.; Feinstein, Stuart C.; Wang, Xiaobo; Xu, Xiao

    2010-01-01

    Summary We describe a cell-based kinetic profiling approach using impedance readout for monitoring the effect of small molecule compounds. This non-invasive readout allows continuous sampling of cellular responses to biologically active compounds and the ensuing kinetic profile provides information regarding the temporal interaction of compounds with cells. The utility of this approach was tested by screening a library containing FDA approved drugs, experimental compounds and nature compounds. Compounds with similar activity produced similar impedance-based time-dependent cell response profiles (TCRP). The compounds were clustered based on TCRP similarity. We identified novel mechanisms for existing drugs, confirmed previously reported calcium modulating activity for COX-2 inhibitor, celecoxib and identified an additional mechanism for the experimental compound, monastrol. We also identified and characterized a new anti-mitotic agent. Our findings indicate TCRP approach provides predictive mechanistic information for small molecule compounds. PMID:19635408

  11. Ionic liquid-based dispersive liquid-liquid microextraction with back-extraction coupled with capillary electrophoresis to determine phenolic compounds.

    PubMed

    Zhou, Caihong; Tong, Shanshan; Chang, Yunxia; Jia, Qiong; Zhou, Weihong

    2012-04-01

    Ionic liquid (IL) based dispersive liquid-liquid microextraction (DLLME) with back-extraction coupled with capillary electrophoresis ultraviolet detection was developed to determine four phenolic compounds (bisphenol-A, β-naphthol, α-naphthol, 2, 4-dichlorophenol) in aqueous cosmetics. The developed method was used to preconcentrate and clean up the four phenolic compounds including two steps. The analytes were transferred into room temperature ionic liquid (1-octyl-3-methylimidazolium hexafluorophosphate, [C(8) MIM][PF(6) ]) rich-phase in the first step. In the second step, the analytes were back-extracted into the alkaline aqueous phase. The effects of extraction parameters, such as type and volume of extraction solvent, type and volume of disperser, extraction and centrifugal time, sample pH, salt addition, and concentration and volume of NaOH in back-extraction were investigated. Under the optimal experimental conditions, the preconcentration factors were 60.1 for bisphenol-A, 52.7 for β-naphthol, 49.2 for α-naphthol, and 18.0 for 2, 4-dichlorophenol. The limits of detection for bisphenol-A, β-naphthol, α-naphthol and 2, 4-dichlorophenol were 5, 5, 8, and 100 ng mL(-1), respectively. Four kinds of aqueous cosmetics including toner, soften lotion, make-up remover, and perfume were analyzed and yielded recoveries ranging from 81.6% to 119.4%. The main advantages of the proposed method are quick, easy, cheap, and effective.

  12. Photoprotective effect and acute oral systemic toxicity evaluation of the novel heterocyclic compound LQFM048.

    PubMed

    Vinhal, Daniela C; de Ávila, Renato Ivan; Vieira, Marcelo S; Luzin, Rangel M; Quintino, Michelle P; Nunes, Liliane M; Ribeiro, Antonio Carlos Chaves; de Camargo, Henrique Santiago; Pinto, Angelo C; Dos Santos Júnior, Helvécio M; Chiari, Bruna G; Isaac, Vera; Valadares, Marize C; Martins, Tatiana Duque; Lião, Luciano M; de S Gil, Eric; Menegatti, Ricardo

    2016-08-01

    The new heterocyclic derivative LQFM048 (3) (2,4,6-tris ((E)-ethyl 2-cyano-3-(4-hydroxy-3-methoxyphenyl)acrylate)-1,3,5-triazine) was originally designed through the molecular hybridization strategy from Uvinul® T 150 (1) and (E)-ethyl 2-cyano-3-(4hydroxy-3-methoxyphenyl)acrylate (2) sunscreens, using green chemistry approach. This compound was obtained in global yields (80%) and showed an interesting redox potential. In addition, it is thermally stable up to temperatures around 250°C. It was observed that LQFM048 (3) showed a low degradation after 150min of sunlight exposure at 39°C, whereas the extreme radiation conditions induced a considerable photodegradation of the LQFM048 (3), especially when irradiated by VIS and VIS+UVA. During the determination of sun protection factor, LQFM048 (3) showed interesting results, specially as in association with other photoprotective compounds and commercial sunscreen. Additionally, the compound (3) did not promote cytotoxicity for 3T3 fibroblasts. Moreover, it was not able to trigger acute oral systemic toxicity in mice, being classified as a compound with low acute toxicity hazard (2.000mg/kg>LD50<5.000mg/kg). Therefore, this compound synthesized using green chemistry approach is promising showing potential to development of a new sunscreen product with advantage of presenting redox potential, indicating antioxidant properties.

  13. Photoprotective effect and acute oral systemic toxicity evaluation of the novel heterocyclic compound LQFM048.

    PubMed

    Vinhal, Daniela C; de Ávila, Renato Ivan; Vieira, Marcelo S; Luzin, Rangel M; Quintino, Michelle P; Nunes, Liliane M; Ribeiro, Antonio Carlos Chaves; de Camargo, Henrique Santiago; Pinto, Angelo C; Dos Santos Júnior, Helvécio M; Chiari, Bruna G; Isaac, Vera; Valadares, Marize C; Martins, Tatiana Duque; Lião, Luciano M; de S Gil, Eric; Menegatti, Ricardo

    2016-08-01

    The new heterocyclic derivative LQFM048 (3) (2,4,6-tris ((E)-ethyl 2-cyano-3-(4-hydroxy-3-methoxyphenyl)acrylate)-1,3,5-triazine) was originally designed through the molecular hybridization strategy from Uvinul® T 150 (1) and (E)-ethyl 2-cyano-3-(4hydroxy-3-methoxyphenyl)acrylate (2) sunscreens, using green chemistry approach. This compound was obtained in global yields (80%) and showed an interesting redox potential. In addition, it is thermally stable up to temperatures around 250°C. It was observed that LQFM048 (3) showed a low degradation after 150min of sunlight exposure at 39°C, whereas the extreme radiation conditions induced a considerable photodegradation of the LQFM048 (3), especially when irradiated by VIS and VIS+UVA. During the determination of sun protection factor, LQFM048 (3) showed interesting results, specially as in association with other photoprotective compounds and commercial sunscreen. Additionally, the compound (3) did not promote cytotoxicity for 3T3 fibroblasts. Moreover, it was not able to trigger acute oral systemic toxicity in mice, being classified as a compound with low acute toxicity hazard (2.000mg/kg>LD50<5.000mg/kg). Therefore, this compound synthesized using green chemistry approach is promising showing potential to development of a new sunscreen product with advantage of presenting redox potential, indicating antioxidant properties. PMID:27208746

  14. Dietary fiber and phenolic compounds as functional ingredients: interaction and possible effect after ingestion.

    PubMed

    Quirós-Sauceda, A E; Palafox-Carlos, H; Sáyago-Ayerdi, S G; Ayala-Zavala, J F; Bello-Perez, L A; Alvarez-Parrilla, E; de la Rosa, L A; González-Córdova, A F; González-Aguilar, G A

    2014-06-01

    Dietary fiber and phenolic compounds are two recognized dietary factors responsible for potential effects on human health; therefore, they have been widely used to increase functionality of some foods. This paper focuses on showing the use of both substances as functional ingredients for enriching foods, and at the same time, describes the use of a single material that combines the properties of the two types of substances. The last part of the work describes some facts related to the interaction between dietary fiber and phenolic compounds, which could affect the bioaccessibility and absorption of phenolics in the gut. In this sense, the purpose of the present review is to compile and analyze evidence relating to the use of dietary fiber and phenolic compounds to enhance technological and nutritional properties of foods and hypothesize some of the possible effects in the gut after their ingestion.

  15. Effect of Stevia rebaudiana addition on bioaccessibility of bioactive compounds and antioxidant activity of beverages based on exotic fruits mixed with oat following simulated human digestion.

    PubMed

    Carbonell-Capella, Juana M; Buniowska, Magdalena; Esteve, María J; Frígola, Ana

    2015-10-01

    In order to determine the impact of Stevia rebaudiana (SR) addition on bioactive compounds bioaccessibility of a new developed functional beverage based on exotic fruits (mango juice, papaya juice and açaí) mixed with orange juice and oat, an in vitro gastrointestinal digestion was performed. Ascorbic acid, total carotenoids, total phenolics, total anthocyanins, total antioxidant capacity and steviol glycosides were evaluated before and after a simulated gastrointestinal digestion. Salivary and gastric digestion had no substantial effect on any of the major phenolic compounds, ascorbic acid, total antioxidant capacity and steviol glycosides, whereas carotenoids and anthocyanins diminished significantly during the gastric step. All analysed compounds were significantly altered during the pancreatic-bile digestion and this effect was more marked for carotenoids and total anthocyanins. However, phenolic compounds, anthocyanins, total antioxidant capacity and steviol glycosides bioaccessibility increased as did SR concentration. Ascorbic acid bioaccessibility was negatively affected by the SR addition. PMID:25872434

  16. Effect of Stevia rebaudiana addition on bioaccessibility of bioactive compounds and antioxidant activity of beverages based on exotic fruits mixed with oat following simulated human digestion.

    PubMed

    Carbonell-Capella, Juana M; Buniowska, Magdalena; Esteve, María J; Frígola, Ana

    2015-10-01

    In order to determine the impact of Stevia rebaudiana (SR) addition on bioactive compounds bioaccessibility of a new developed functional beverage based on exotic fruits (mango juice, papaya juice and açaí) mixed with orange juice and oat, an in vitro gastrointestinal digestion was performed. Ascorbic acid, total carotenoids, total phenolics, total anthocyanins, total antioxidant capacity and steviol glycosides were evaluated before and after a simulated gastrointestinal digestion. Salivary and gastric digestion had no substantial effect on any of the major phenolic compounds, ascorbic acid, total antioxidant capacity and steviol glycosides, whereas carotenoids and anthocyanins diminished significantly during the gastric step. All analysed compounds were significantly altered during the pancreatic-bile digestion and this effect was more marked for carotenoids and total anthocyanins. However, phenolic compounds, anthocyanins, total antioxidant capacity and steviol glycosides bioaccessibility increased as did SR concentration. Ascorbic acid bioaccessibility was negatively affected by the SR addition.

  17. Heterocyclic compounds: toxic effects using algae, daphnids, and the Salmonella/microsome test taking methodical quantitative aspects into account.

    PubMed

    Eisentraeger, Adolf; Brinkmann, Corinna; Hollert, Henner; Sagner, Anne; Tiehm, Andreas; Neuwoehner, Judith

    2008-07-01

    Heterocyclic aromatic hydrocarbons containing nitrogen, sulfur, or oxygen (NSO-HET), have been detected in air, soil, sewage sludge, marine environments, and freshwater sediments. Since toxicity data on this class of substances are scarce, the present study focuses on possible implications NSO-HET have for ecotoxicity (algae and daphnids) and mutagenicity (Salmonella/microsome test). A combination of bioassays and chemical-analytical quantification of the test compounds during toxicity assays should aid in determination of the hazard potential. Samples of the test concentrations of 14 NSO-HET were taken at the beginning and end of the bioassays; these samples were then quantified by high-performance liquid chromatography. The toxicity potential of the substances was evaluated and compared with the toxicity calculated with the nominal concentrations. Significantly different results were obtained primarily for volatile or highly hydrophobic NSO-HET. The concentration of heterocyclic hydrocarbons can change significantly during the algae and Daphnia test. The EC50 values (effective concentration value: the concentration of a chemical that is required to produce a 50% effect) calculated with the nominal concentrations underestimate the toxicity by a factor of up to 50. Prioritizing the tested compounds according to toxicity, the mutagenic and toxic compounds quinoline, 6-methylquinoline, and xanthene have to be listed first. The greatest ecotoxic potential on algae and daphnids was determined for dibenzothiophene followed by acridine. In the Daphnia magna immobilization test, benzofuran, dibenzofuran, 2-methylbenzofuran, and 2,3-dimethylbenzofuran and also carbazole are ecotoxicologically relevant with EC50 values below 10 mg/L. These substances are followed by indole with a high ecotoxic effect to daphnids and less effect to algae. Only minor toxic effects were observed for 2-methylpyridine and 2,4,6-trimethylpyridine.

  18. Effect of temperature on the chromatographic retention of ionizable compounds. I. Methanol-water mobile phases.

    PubMed

    Castells, Cecilia B; Gagliardi, Leonardo G; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2004-07-01

    The retention mechanism of acids and bases in reversed-phase liquid chromatography (RPLC) has been experimentally studied by examining the temperature dependence of retention, with emphasis on the role of the buffer ionization equilibria in the retention and selectivity. Retention factors of several ionizable compounds in a typical octadecylsilica column and using buffers dissolved in 50% (w/w) methanol as eluents at three temperatures in the range of 25-50 degrees C were measured. Two pairs of buffer solutions were prepared by a close adjusting of their pH at 25 degrees C; differences in their ionization enthalpies determined a different degree of ionization when temperature was raised and, as a consequence, a different shift in the eluent pH. Predictive equations of retention that take into account the temperature effect on both the transfer and the ionization processes are proposed. This study demonstrates the significant role that the selected buffer would have in retention and selectivity in RPLC at temperatures higher than 25 degrees C, particularly for co-eluted solutes. PMID:15296385

  19. Characterization the effect of disulfide compound on the devulcanization of thermoplastic vulcanizate

    NASA Astrophysics Data System (ADS)

    Rodsuk, Sikarin; Ritsuar, Suphattarachai; Wattanakul, Karnthidaporn

    2012-09-01

    The use of disulfides and the application of mechanical force in rubber devulcanization have been reported in the literatures. In this work, the devulcanization of thermoplastic vulcanizate (TPVs) which is polypropylene/ethylene propylene diene rubber blend, is conducted in a Brabender batch mixer using diphenyl disulfide as the devulcanizing agent. Considering the complexity of the compound, the effect of devulcanizing agent concentration, temperature and time were investigated to obtain the optimum condition. The extent of devulcanization of thermoplastic vulcanizate was studied by determination the volume fraction of dried rubber after swelling and crosslink density. The result show that the crosslink density of devulcanized TPVs decreased to 60.33% and 68.24% for 1 phr and 5 phr, respectively, and significantly decreased to 68.94% by adding 10 phr of diphenyl disulfide at 190°C. Moreover, the percent devulcanization of TPVs increased from 68.24% to 72.12% with increased in the reaction temperature up to 230 °C.

  20. Effect of temperature on the chromatographic retention of ionizable compounds. I. Methanol-water mobile phases.

    PubMed

    Castells, Cecilia B; Gagliardi, Leonardo G; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2004-07-01

    The retention mechanism of acids and bases in reversed-phase liquid chromatography (RPLC) has been experimentally studied by examining the temperature dependence of retention, with emphasis on the role of the buffer ionization equilibria in the retention and selectivity. Retention factors of several ionizable compounds in a typical octadecylsilica column and using buffers dissolved in 50% (w/w) methanol as eluents at three temperatures in the range of 25-50 degrees C were measured. Two pairs of buffer solutions were prepared by a close adjusting of their pH at 25 degrees C; differences in their ionization enthalpies determined a different degree of ionization when temperature was raised and, as a consequence, a different shift in the eluent pH. Predictive equations of retention that take into account the temperature effect on both the transfer and the ionization processes are proposed. This study demonstrates the significant role that the selected buffer would have in retention and selectivity in RPLC at temperatures higher than 25 degrees C, particularly for co-eluted solutes.