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Sample records for 1-pentanol 2-pentanol 3-pentanol

  1. Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis

    PubMed Central

    Song, Geun C.; Choi, Hye K.; Ryu, Choong-Min

    2015-01-01

    3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 μM and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR) gene expression levels associated with defense signaling through salicylic acid (SA), jasmonic acid (JA), and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved SA and JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen. PMID:26500665

  2. Fragrance material review on 1-phenyl-3-methyl-3-pentanol.

    PubMed

    Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 1-phenyl-3-methyl-3-pentanol when used as a fragrance ingredient is presented. 1-Phenyl-3-methyl-3-pentanol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a tertiary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group -C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1-phenyl-3-methyl-3-pentanol were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, and genotoxicity data. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Aryl Alkyl Alcohols in fragrances. PMID:22033089

  3. 3-pentanol: a new attractant present in volatile emissions from the ambrosia beetle, Megaplatypus mutatus.

    PubMed

    Gatti Liguori, Pablo; Zerba, Eduardo; Alzogaray, Raul A; Gonzalez Audino, Paola

    2008-11-01

    Megaplatypus mutatus (=Platypus mutatus) (Coleoptera: Platypodidae) is an ambrosia beetle that is native to South America. It attacks only standing live trees and causes severe stem breakage and death in commercial poplar (Populus) plantations. Previous work showed that male M. mutatus emits a sex pheromone composed mainly of (+)-sulcatol and sulcatone. We collected male volatile emissions during the hours of maximum emergence by using a specific polar microextraction phase; analyzed the extract by GC-MS; and tested the biological activity of selected compounds in the extract with a walking behavioral assay. Female M. mutatus emerged primarily between 7 and 11 h. In the chemical analyses of volatiles, a third compound, 3-pentanol, was identified in a small percentage of samples. Walking behavioral bioassays with video image analysis showed that at the doses tested, 3-pentanol elicited an attractive response from females. PMID:18850328

  4. Field evaluation of the bacterial volatile derivative 3-pentanol in priming for induced resistance in pepper.

    PubMed

    Choi, Hye Kyung; Song, Geun Cheol; Yi, Hwe-Su; Ryu, Choong-Min

    2014-08-01

    Plants are defended from attack by emission of volatile organic compounds (VOCs) that can act directly against pathogens and herbivores or indirectly by recruiting natural enemies of herbivores. However, microbial VOC have been less investigated as potential triggers of plant systemic defense responses against pathogens in the field. Bacillus amyloliquefaciens strain IN937a, a plant growth-promoting rhizobacterium that colonizes plant tissues, stimulates induced systemic resistance (ISR) via its emission of VOCs. We investigated the ISR capacity of VOCs and derivatives collected from strain IN937a against bacterial spot disease caused by Xanthomonas axonopodis pv. vesicatoria in pepper. Of 15 bacterial VOCs and their derivatives, 3-pentanol, which is a C8 amyl alcohol reported to be a component of sex pheromones in insects, was selected for further investigation. Pathogens were infiltrated into pepper leaves 10, 20, 30, and 40 days after treatment and transplantation to the field. Disease severity was assessed 7 days after transplantation. Treatment with 3-pentanol significantly reduced disease severity caused by X. axonopodis and naturally occurring Cucumber mosaic virus in field trials over 2 years. We used quantitative real-time polymerase chain analysis to examine Pathogenesis-Related genes associated with salicylic acid (SA), jasmonic acid (JA), and ethylene defense signaling. The expression of Capsicum annuum Pathogenesis-Related protein 1 (CaPR1), CaPR2, and Ca protease inhibitor2 (CaPIN2) increased in field-grown pepper plants treated with 3-pentanol. Taken together, our results show that 3-pentanol triggers induced resistance by priming SA and JA signaling in pepper under field conditions. PMID:25149655

  5. Molecular interactions in binary mixtures of methyl formate with 1-butanol, 1-pentanol, and 1-hexanol by using ultrasonic data at 303 K

    NASA Astrophysics Data System (ADS)

    Elangovan, S.; Mullainathan, S.

    2016-05-01

    Density (ρ), viscosity (η), and ultrasonic velocity ( U) have been measured for binary mixtures of methyl formate with 1-butanol, 1-pentanol and 1-hexanol at 303 K. From the experimental results, adiabatic compressibility (β), acoustic impedance ( Z), viscous relaxation time (τ), free length ( L f), free volume ( V f), internal pressure (πi), and Gibbs free energy (Δ G) have been determined. Excess values of various parameters have also been calculated and interoperated in terms of molecular interactions. The deviations in the parameters show that strength of intermolecular interactions between methyl formate with selected 1-alcohols have been observed in the order of 1-butanol < 1-pentanol < 1-hexanol.

  6. Excess parameters for binary mixtures of ethyl benzoate with 1-propanol, 1-butanol and 1-pentanol at T=303, 308, 313, 318, and 323 K

    NASA Astrophysics Data System (ADS)

    Sreehari Sastry, S.; Babu, Shaik; Vishwam, T.; Parvateesam, K.; Sie Tiong, Ha.

    2013-07-01

    Various thermo-acoustic parameters, such as excess isentropic compressibility (KsE), excess molar volume (VE), excess free length (LfE), excess Gibb's free energy (ΔG*E), and excess Enthalpy (HE), have been calculated from the experimentally determined data of density, viscosity and speed of sound for the binary mixtures of ethyl benzoate+1-propanol, or +1-butanol, or +1-pentanol over the entire range of composition at different temperatures (303, 308, 313, 318 and 323 K). The excess functions have been fitted to the Redlich-Kister type polynomial equation. The deviations for excess thermo-acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures.

  7. Preparation of zeolite supported TiO2, ZnO and ZrO2 and the study on their catalytic activity in NOx reduction and 1-pentanol dehydration

    NASA Astrophysics Data System (ADS)

    Fatimah, Is

    2016-03-01

    Preparation of zeolite supported TiO2, ZnO and ZrO2 and their catalytic activity was studied. Activated natural zeolite from Indonesia was utilized for the preparation and catalytic activity test on NOx reduction by NH3 and also 1-pentanol dehydration were examined. Physicochemical characterization of materials was studied by x-ray diffraction (XRD) measurement, scanning electron microscope, solid acidity determination and also gas sorption analysis. The results confirmed that the preparation gives some improvements on physicochemical characters suitable for catalysis mechanism in those reactions. Solid acidity and specific surface area contributed significantly to the activity.

  8. The critical behavior of the dielectric constant in the polar + polar binary liquid mixture nitromethane + 3-pentanol: an unusual sign of its critical amplitude in the one-phase region.

    PubMed

    Leys, Jan; Losada-Pérez, Patricia; Troncoso, Jacobo; Glorieux, Christ; Thoen, Jan

    2011-07-14

    Dielectric constant measurements have been carried out in the one- and two-phase regions near the critical point of the polar + polar binary liquid mixture nitromethane + 3-pentanol. In the two-phase region, evidence for the |t|(2β) singularity in the coexistence-curve diameter has been detected, thus confirming the novel predictions of complete scaling theory for liquid-liquid criticality. In the one-phase region, an "unusual" negative sign for the amplitude of the |t|(1-α) singularity has been encountered for the first time in an upper critical solution temperature type of binary liquid mixture at atmospheric pressure. Mass density measurements have also been carried out to provide additional information related to such experimental finding, which entails an increase of the critical temperature T(c) under an electric field. PMID:21766958

  9. Surface behavior of amphiphiles in aqueous solution: a comparison between different pentanol isomers.

    PubMed

    Walz, M-M; Caleman, C; Werner, J; Ekholm, V; Lundberg, D; Prisle, N L; Öhrwall, G; Björneholm, O

    2015-06-01

    Position isomerism is ubiquitous in atmospheric oxidation reactions. Therefore, we have compared surface-active oxygenated amphiphilic isomers (1- and 3-pentanol) at the aqueous surface with surface- and chemically sensitive X-ray photoelectron spectroscopy (XPS), which reveals information about the surface structure on a molecular level. The experimental data are complemented with molecular dynamics (MD) simulations. A concentration-dependent orientation and solvation of the amphiphiles at the aqueous surface is observed. At bulk concentrations as low as around 100 mM, a monolayer starts to form for both isomers, with the hydroxyl groups pointing towards the bulk water and the alkyl chains pointing towards the vacuum. The monolayer (ML) packing density of 3-pentanol is approx. 70% of the one observed for 1-pentanol, with a molar surface concentration that is approx. 90 times higher than the bulk concentration for both molecules. The molecular area at ML coverage (≈100 mM) was calculated to be around 32 ± 2 Å(2) per molecule for 1-pentanol and around 46 ± 2 Å(2) per molecule for 3-pentanol, which results in a higher surface concentration (molecules per cm(2)) for the linear isomer. In general we conclude therefore that isomers - with comparable surface activities - that have smaller molecular areas will be more abundant at the interface in comparison to isomers with larger molecular areas, which might be of crucial importance for the understanding of key properties of aerosols, such as evaporation and uptake capabilities as well as their reactivity. PMID:25953683

  10. Composition and Process for Retarding the Premature Aging of PMR Monomer Solutions and PMR Prepegs

    NASA Technical Reports Server (NTRS)

    Alston, William B. (Inventor); Gahn, Gloria S. (Inventor)

    2000-01-01

    Polyimides are derived from solutions of at least one low-boiling organic solvent, e.g. isopropanol containing a mixture of polyimide-forming monomers. The monomeric solutions have an extended shelf life at ambient (room) temperatures as high as 80 C, and consist essentially of a mixture of monoalkyl ester-acids, alkyl diester-diacids and aromatic polyamines wherein the alkyl radicals of the esteracids are derived from lower molecular weight aliphatic secondary alcohols having 3 to 5 carbon atoms per molecule such as isopropanol, secondary butanol, 2-methyl-3-butanol, 2 pentanol or 3-pentanol. The solutions of the polyimide-forming monomers have a substantially improved shelf-life and are particularly useful in the aerospace and aeronautical industry for the preparation of polyimide reinforced fiber composites such as the polyimide cured carbon composites used in jet engines, missiles, and for other high temperature applications.

  11. Effect of Surfactant Supplying with Refrigerant Vapor on Absorption Enhancement

    NASA Astrophysics Data System (ADS)

    Gao, Hongtao; Matsuzaki, Tetsuya; Wang, Jianfeng; Hihara, Eiji

    For the absorption of water vapor into the aqueous lithium bromide solution, eight-carbon alcohol additives such as 2-ethyl-1-hexanolhave been commonly used to improve the absorption process. However, as additives six-carbon and seven-carbon alcohols were not been tested experimentally very much. In present study, absorption of water vapor into the 62 wt% LiBr solution with several six-carbon and seven carbon alcohol additives such as 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-hexanol, 2 , 4-dimethyl-3-pentanol, 4-heptanol, 2-heptanol and 1-heptanol were investigated by using a simple stagnant pool absorber. Besides using the conventional method which mixing additive into LiBr solution, vapor phase adding method was experimented. Surface tensions of aqueous LiBr solution with different surfactant also were measured by Welhelmy plate method. Absorption of water vapor into the LiBr solution with 2-ethyl-1-hexanol and 1-heptanol were also experimented in falling film absorber by vapor phase adding method. The result showed that the lower the surface tension of LiBr aqueous solution with an additive, the better the effect of absorption enhancement by the corresponding additive, and vapor phase adding method is effective for the absorption of water vapor into the LiBr aqueous solution.

  12. An investigation of bubble coalescence and post-rupture oscillation in non-ionic surfactant solutions using high-speed cinematography.

    PubMed

    Bournival, G; Ata, S; Karakashev, S I; Jameson, G J

    2014-01-15

    Most processes involving bubbling in a liquid require small bubbles to maximise mass/energy transfer. A common method to prevent bubbles from coalescing is by the addition of surfactants. In order to get an insight into the coalescence process, capillary bubbles were observed using a high speed cinematography. Experiments were performed in solutions of 1-pentanol, 4-methyl-2-pentanol, tri(propylene glycol) methyl ether, and poly(propylene glycol) for which information such as the coalescence time and the deformation of the resultant bubble upon coalescence was extracted. It is shown in this study that the coalescence time increases with surfactant concentration until the appearance of a plateau. The increase in coalescence time with surfactant concentration could not be attributed only to surface elasticity. The oscillation of the resultant bubble was characterised by the damping of the oscillation. The results suggested that a minimum elasticity is required to achieve an increased damping and considerable diffusion has a detrimental effect on the dynamic response of the bubble, thereby reducing the damping. PMID:24231084

  13. Relative contribution of oxygenated hydrocarbons to the total biogenic VOC emissions of selected mid-European agricultural and natural plant species

    NASA Astrophysics Data System (ADS)

    König, Georg; Brunda, Monika; Puxbaum, Hans; Hewitt, C. Nicholas; Duckham, S. Craig; Rudolph, Jochen

    Emission rates of more than 50 individual VOCs were determined for eight plant species and three different types of grass land typical for natural deciduous and agricultural vegetation in Austria. In addition to the emissions of isoprene and monoterpenes, 33 biogenic oxygenated volatile organic compounds (BOVOCs) were detected. Of these, 2-methyl-l-propanol, 1-butanal, 2-butanal, 1-pentanol, 3-pentanol, 1-hexanol, 6-methyl-5-hepten-2-one, butanal and ethylhexylacetate were observed for the first time as plant emissions. In terms of prevalence of one of the groups of emitted VOCs (isoprene, terpenes, BOVOCs) the grain plants wheat and rye, grape, oilseed rape and the decidous trees hombeam and birch could be classified as "BOVOC"-emitters. For the grass plots examined, BOVOCs and terpenes appear to be of equal importance. The emission rates of the total assigned organic plant emissions ranged from 0.01 μ g -1 h -1 for wheat to 0.8 μg g -1 h -1 for oak (based on dry leaf weight). Intercomparison with available data from other studies show that our emission rates are rather at the lower end of reported ranges. The influence of the stage of growth was examined for rye, rape (comparing emissions of blossoming and nonblossoming plants) and for grape (with and without fruit). Emission rate differences for different stages of growth varied from nondetectable for blossoming and nonblossoming rye to a factor of six for the grape with fruits vs grape without fruits (emission rate based on dry leaf weight). The major decidous tree in Austria (beech) is a terpene emitter, with the contribution of BOVOCs below 5% of the total assigned emissions of 0.2 μg g -1 h -1 for the investigations of 20°C.

  14. Characteristics of chemical binding to alpha 2u-globulin in vitro--evaluating structure-activity relationships

    SciTech Connect

    Borghoff, S.J.; Miller, A.B.; Bowen, J.P.; Swenberg, J.A. )

    1991-02-01

    alpha 2u-Globulin (alpha 2u) has been shown to accumulate in the kidneys of male rats treated with 2,2,4-trimethylpentane (TMP). 2,4,4-Trimethyl-2-pentanol (TMP-2-OH), a metabolite of TMP, is found reversibly bound to alpha 2u isolated from the kidneys of these treated rats. The objectives of the following study were to characterize the ability of (3H)TMP-2-OH to bind to alpha 2u in vitro and to determine whether other compounds that cause this protein to accumulate have the same binding characteristics. Although compounds that have been shown to cause the accumulation of alpha 2u in male rat kidneys compete in vitro with (3H)TMP-2-OH for binding to alpha 2u, they do so to varying degrees. The binding affinity (Kd) of the (3H)TMP-2-OH-alpha 2u complex was calculated to be on the order of 10(-7) M. The inhibition constant values (Ki) determined for d-limonene, 1,4-dichlorobenzene, and 2,5-dichlorophenol were all in the range 10(-4) M, whereas the Ki values for isophorone, 2,4,4- or 2,2,4-trimethyl-1-pentanol, and d-limonene oxide were determined to be in the range 10(-6) and 10(-7) M, respectively. TMP and 2,4,4- and 2,2,4-trimethylpentanoic acid did not compete for binding. This suggests that other factors, besides binding, are involved in the accumulation of alpha 2u. In this study the ability of a chemical to bind to alpha 2u was used as a measure of biological activity to assess structure-activity relationships among the chemicals tested and known to cause the accumulation of alpha 2u. The results so far suggest that binding is dependent on both hydrophobic interactions and hydrogen bonding.

  15. Liquid chromatographic analysis of coal surface properties. Final report, September 1991--February 1995

    SciTech Connect

    Kwon, K.C.

    1996-03-01

    Experiments on equilibrium adsorption loadings of various probe compounds on 60-200 mesh Illinois {number_sign}6 coal (PSOC-1539), Adaville {number_sign}1 coal (PSOC-1544), Wyodak coal (PSOC-1545) and Pittsburgh {number_sign}8 coal (PSOC-1549) were performed. the probe compounds include m-cresol, p-cresol, o-cresol, phenol, n-octanol, n-heptanol, n-propanol, isopropanol n-butanol, s-butanol, 2-butanol, t-butanol, 2-naphthol, cyclohexanol, 2-methyl-1-pentanol (2M1P), 4-methyl-2-pentanol (4M2P), benzene and toluene. Equilibrium adsorption of various probe compounds on the coals were measured with the inverse liquid chromatography method. Experiments on flotation of various 60-200 mesh treated coals such as Illinois {number_sign}6 coal (PSOC-1539), Adaville {number_sign}1 coal (PSOC-1544), Wyodak coal (PSOC-1545) and Pittsburgh {number_sign}8 coal (PSOC-1549) were performed. The chosen coals were treated with steam, nitrogen and air at 1 atm and 125-225{degrees}C for 24 hours. The coals were treated with water as well as 20-1000 ppm aqueous alcohol solutions for 3-24 hours at 150-225{degrees}C. The coals also were treated with 20-ppm alcohol aqueous solutions for 1-24 hours at the 0.002-g/min mass flow rate of alcohol aqueous solutions and at 225{degrees}C. Flotation experiments were conducted with a 500-cm{sup 3} batch-type micro flotation apparatus, introducing nitrogen at the bottom of the apparatus. This final report was prepared with the experimental data obtained during the period of September 1991-March 1994.

  16. Non-fermentation route to ethanol from biomass. Final report, September 1, 1979-August 31, 1980

    SciTech Connect

    Bedenbaugh, A.O.

    1980-09-30

    The purposes of this investigation were twofold: (1) to reduce furfural to ethanol via the lithium-amine system which we had previously shown to be capable of reducing other furan compounds; and (2) to determine whether it would be possible to essentially duplicate lithium-amine reduction of furfural by gamma radiolysis of amine solutions of furfural. Evidence that both ethanol and 2-pentanol were produced from the radiolysis of 2-methyfuran in ethylenediamine is presented. The magnitude of the effect of lithium salt on the radiolysis was not determined; however, ethanol and 2-pentanol were noted in a radiolysis in which lithium chloride was present. (MF)

  17. Preparation of 2-Bromopentane.

    ERIC Educational Resources Information Center

    Howell, B. A.; Kohrman, R. E.

    1984-01-01

    Suggests that the preparation of 2-bromopentane from 2-pentanol might represent an instructive addition to a published description of pheromone synthesis in that it is economical, extends the synthetic nature of the problem, and amplifies the mechanistic vagaries of the substitution reaction. Theory, procedures used, and safety considerations are…

  18. A rhodamine-deoxylactam based sensor for chromo-fluorogenic detection of nerve agent simulant.

    PubMed

    Wu, Zhisheng; Wu, Xuanjun; Yang, Yuhui; Wen, Ting-bin; Han, Shoufa

    2012-10-15

    N-(rhodamine B)-deoxylactam-5-amino-1-pentanol (dRB-APOH) was designed and prepared as the chromo-fluorogenic sensor for detection of a nerve agent simulant via analyte triggered tandem phosphorylation and opening of the intramolecular deoxylactam. The successful detection of diethyl chlorophosphate suggests the utility of rhodamine-deoxylactams as the chromo-fluorogenic signal reporting platform for design of sensors targeting reactive chemical species via various chemistries. PMID:22995618

  19. Behavioral and electrophysiological responses of Aedes albopictus to certain acids and alcohols present in human skin emanations.

    PubMed

    Guha, Lopamudra; Seenivasagan, T; Iqbal, S Thanvir; Agrawal, O P; Parashar, B D

    2014-10-01

    Human skin emanations attract hungry female mosquitoes toward their host for blood feeding. In this study, we report the flight orientation and electroantennogram response of Aedes albopictus females to certain unsaturated acids and alcohols found in human skin. In the Y-tube olfactometer, odors of lactic acid and 2-methyl-3-pentanol attracted 54-65% of Ae. albopictus females at all doses in a dose-dependent manner. However, at the highest dose (10(-2) g), the acids repelled 40-45% females. Attractancy (ca. 62-68%) at lower doses and repellency (ca. 30-45%) at higher doses were recorded for 3-methyl-3-pentanol and 1-octen-3-ol, while 5-hexen-1-ol, cis-2-hexen-1-ol, and trans 2-hexen-1-ol odor repelled ca. 55-65% of Ae. albopictus females at all doses. Antenna of female Ae. albopictus exhibited a dose-dependent EAG response up to 10(-3) g of L-lactic acid, trans-2-methyl-2-pentenoic acid, 2-octenoic acid, trans-2-hexen-1-ol and 1-octen-3-ol stimulations; however, the highest dose (10(-2) g) caused a little decline in the EAG response. EAG response of 9-10-fold was elicited by lactic acid, 2-octenoic acid, trans-2-hexenoic acid, and 3-methyl-3-pentanol, while cis-2-hexen-1-ol and trans-2-methyl pentenoic acid elicited 1-5-fold responses compared to solvent control. A blend of attractive compounds could be utilized in odor-baited trap for surveillance and repellent molecules with suitable formulation could be used to reduce the biting menace of mosquitoes. PMID:25049052

  20. Characterization and utilization of a novel triflate ionic liquid stationary phase for use in comprehensive two-dimensional gas chromatography.

    PubMed

    Reid, Vanessa R; Crank, Jeffery A; Armstrong, Daniel W; Synovec, Robert E

    2008-10-01

    A novel triflate (trifluoromethylsulfonate) ionic liquid (IL) thin film (0.08 microm) stationary phase was implemented for use within the second column of a comprehensive GC x GC configuration. The first column in the configuration had a 5% phenyl/95% dimethyl polysiloxane (DMPS) stationary phase with a 0.4 microm film. The DMPS x IL column configuration was used to separate a mixture of 32 compounds of various chemical functional classes. The GC x GC results for the IL column were compared with a commercially available polar column (with a 0.1 microm PEG stationary phase film) used as the second column instead. Additional studies focused on the rapid and selective separation of four phosphorous-oxygen (P-O) containing compounds from the 32-compound matrix: dimethyl methylphosphonate (DMMP), diethyl methylphosphonate (DEMP), diisopropyl methylphosphonate (DIMP), and triethyl phosphate (TEP). van't Hoff plots (plots of ln k vs. 1/T) demonstrated the difference in retention between the P-O containing compounds (with DMMP reported in detail) and other classes of compounds (i. e., 2-pentanol and n-dodecane as representative) using either the IL column or the commercial PEG column. The selectivity (alpha) of the triflate IL column and the commercially available PEG column were also compared. The IL column provided significantly larger selectivities between DMMP and the other two compounds (2-pentanol and n-dodecane) than the commercial PEG column. The alpha for DMMP relative to n-dodecane was 3.0-fold greater for the triflate IL column, and the alpha for DMMP relative to 2-pentanol was 1.7-fold greater for the triflate IL column than for the PEG column. PMID:18798215

  1. The Effect of Cavitating Ultrasound on the Heterogeneous Aqueous Hydrogenation of 3-buten-2-ol on Pd-black

    SciTech Connect

    Disselkamp, Robert S.; Chin, Ya-Huei; Peden, Charles HF.

    2004-10-25

    The effect of ultrasound at 20 kHz on the heterogeneous aqueous hydrogenation of 3-buten-2-ol employing a Pd-black catalyst has been studied isothermally at 295 K, forming 2-butanone and 2-butanol products. Our work here shows that adding 1-pentanol as an inert dopant had the effect of inducing cavitation in the ultrasound-treated reaction where it otherwise would not occur. The selectivity showed a 700% increase toward 2-butanol formation and the activity enhanced a factor of 10.8 compared to the noncavitating high-power ultrasound experiment. This study demonstrates that ''inert dopants'' may have use as synthetic tools in sonocatalysis.

  2. Densities, molar volumes, cubic expansion coefficients, and isothermal compressibilities of 1-alkanols from 323. 15 K to 373. 15 K and pressures up to 10 MPa

    SciTech Connect

    Garg, S.K.; Banipal, T.S.; Ahluwalia, J.C. )

    1993-04-01

    Densities of six alcohols, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, and 1-dodecanol, in the liquid state have been measured with a vibrating-tube densimeter from 323.15 to 373.15 K at pressures up to 10 MPa. Molar volumes (derived from the densities) have been fitted to polynomials as a function of temperature and pressure. Cubic expansion coefficients and isothermal compressibilities have been derived from molar volumes as a function of temperature and pressure. The results have also been compared with the available literature values.

  3. Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme

    DOEpatents

    Koch, Daniel J.; Arnold, Frances H.

    2013-01-29

    Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.

  4. Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

    NASA Astrophysics Data System (ADS)

    Nikolić, G. M.; Živković, J. V.; Atanasković, D. S.; Nikolić, M. G.

    2013-12-01

    Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.

  5. Effect of release rate and enantiomeric composition on response to pheromones of Megaplatypus mutatus (Chapuis) in poplar plantations of Argentina and Italy.

    PubMed

    Funes, Hernán; Zerba, Eduardo; Gonzalez-Audino, Paola

    2013-10-01

    Megaplatypus mutatus (=Platypus sulcatus Chapuis) is an Ambrosia beetle native to South America, which was recently introduced in Italy and its presence there is causing severe damage to the local poplar plantations. The male M. mutatus pheromone is composed of (S)-(+)-6-methyl-5-hepten-2-ol [(+)-sulcatol], 6-methyl-5-hepten-2-one (sulcatone) and 3-pentanol. A series of field trials testing dose, blend and enantiomer composition performed in Argentina and Italy evaluated attraction and found that the optimal release rate of pheromone components as baits in cross vane baited traps (CIPEIN-CV) was 6, 6 and 30 mg day−1 of sulcatone, (+)-sulcatol and 3-pentanol, respectively. It was also determined that racemic sulcatol is as effective as the pure (+)-isomer for the purpose of beetle catch, due to the inert nature of the (−)-isomer allowing the usage of low cost racemic sulcatol instead of highly expensive (+)-sulcatol. The results of our work contribute to the development of pheromone-based local technologies with low environmental impact and low cost for control or monitoring of an important pest. PMID:23590828

  6. Graphite furnace-atomic absorption spectrophotometric determination of palladium in soil.

    PubMed

    Patel, K S; Sharma, P C; Hoffmann, P

    2000-08-01

    A new and sensitive procedure for the graphite furnace-atomic absorption spectrophotometric (GF-AAS) determination of Pd in soil at nanogram level is described. The method is based on prior separation and enrichment of the metal as Pd(II)-SnCl3- -N-butylacetamide (BAA) complex into 1-pentanol (PN) by solvent extraction method. The value of the molar absorptivity of the complex in three solvents, i.e. ethyl acetate, 1-pentanol, chloroform, lie in the range of (0.70-2.75) x 10(4) L mol(-1) cm(-1) at lambda(max) 360-440 nm. The metal could be enriched into organic solvent, i.e. PN, up to 10-folds. The sensitivity (A = 0.0044) of the method in the term of the peak height was 0.5 ng Pd/mL of the aqueous solution at an enrichment factor (EF) of 5. Optimization of analytical variables during enrichment and GF-AAS determination of the metal are discussed. The method has been applied for the analysis of Pd to soil samples derived from roads and highways in Germany. PMID:11220609

  7. Biosynthesis and characterization of poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) terpolymer with various monomer compositions by Cupriavidus sp. USMAA2-4.

    PubMed

    Ramachandran, Hema; Iqbal, Nurhezreen Md; Sipaut, Coswald Stephen; Abdullah, Amirul Al-Ashraf

    2011-07-01

    Poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-3HV-co-4HB)] terpolymer was produced using Cupriavidus sp. USMAA2-4 via one-step cultivation process through combination of various carbon sources such as 1,4-butanediol or γ-butyrolactone with either 1-pentanol, valeric acid, or 1-propanol. Oleic acid was added to increase the biomass production. The composition of 3HV and 4HB monomers were greatly affected by the concentration of 1,4-butanediol and 1-pentanol. Terpolymers with 3HV and 4HB molar fractions ranging from 2 to 41 mol.% and 5 to 31 mol.%, respectively, were produced by varying the concentration of carbon precursors. The thermal and mechanical properties of the terpolymers containing different proportions of the constituent monomers were characterized using gel permeation chromatography (GPC), DSC, and tensile machine. GPC analysis showed that the molecular weights (M (w)) of the terpolymer produced were within the range of 346 to 1,710 kDa. The monomer compositions of 3HV and 4HB were also found to have great influences on the thermal and mechanical properties of the terpolymer P(3HB-co-3HV-co-4HB) produced. PMID:21302147

  8. Disposition of short-chain aliphatic alcohols in rabbit vitreous by ocular microdialysis.

    PubMed

    Atluri, Harisha; Mitra, Ashim K

    2003-03-01

    Anatomic and physiological barriers limit drug delivery to the posterior segment of the eye via topical or systemic administration. Intravitreal administration has proven to be a safe and effective means of treating various posterior segment diseases. Elimination of a compound from the vitreous chamber may depend on lipophilicity, diffusivity, and aqueous solubility. This information is critical for optimizing intravitreal dosing which in turn can aid in the design of drug delivery systems. The purpose of this study is to determine the vitreous disposition of an ascending homologous series of short chain aliphatic alcohols ranging from hydrophilic methanol to lipophilic 1-heptanol by microdialysis. Radiolabelled 14C-methanol, 14C-1-propanol, 14C-1-pentanol, and 14C-1-heptanol with log partition coefficient values ranging from -0.77 to 2.7 were studied. Microdialysis probes were implanted in both anterior and vitreous chamber of the rabbit eye to sample aqueous and vitreous humors simultaneously. Concentric probe was implanted in vitreous chamber about 3mm below the cornealscleral limbus. Linear probe was implanted in the anterior chamber using a 25-guage needle. Isotonic phosphate buffer saline (IPBS) (pH 7.4) was perfused through the probe with a flow rate of 2 microlml(-1). Alcohols (2.0 microg-130.72 microg) were injected into the vitreous body. In vitro recovery for the probes was calculated using respective alcohols in IPBS. Pharmacokinetic parameters were determined by non-compartmental analysis. Vitreal elimination half-lives of methanol, 1-propanol, 1-pentanol and 1-heptanol are 52.0+/-5.7, 58.5+/-5.8, 72.9+/-5.8 and 153.7+/-21.6 min, respectively. Dose normalized area under the aqueous concentration time curve values of methanol, 1-propanol and 1-pentanol are 33.8+/-13.4, 28.3+/-11.9 and 29.2+/-4.9 microgminml(-1)microg(-1)10(-2), respectively. Time taken to reach maximum concentration in the anterior chamber for methanol, 1-propanol and 1-pentanol is 120

  9. Correlation and prediction of thermodynamic properties of binary mixtures from perturbed chain statistical associating fluid theory

    NASA Astrophysics Data System (ADS)

    Almasi, Mohammad

    2014-11-01

    Densities and viscosities for binary mixtures of Diethanolamine (DEA) + 2 alkanol (2 propanol up to 2 pentanol) were measured over the entire composition range and temperature interval of 293.15-323.15 K. From the density and viscosity data, values of various properties such as isobaric thermal expansibility, excess isobaric thermal expansibility, partial molar volumes, excess molar volumes and viscosity deviations were calculated. The observed variations of these parameters, with alkanols chain length and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. The ability of the perturbed chain statistical associating fluid theory (PC-SAFT) to correlate accurately the volumetric behavior of the binary mixtures is demonstrated.

  10. Headspace analysis of engine oil by gas chromatography/mass spectrometry.

    PubMed

    Levermore, D M; Josowicz, M; Rees, W S; Janata, J

    2001-03-15

    This study establishes the rationale necessary for determining the time to change engine oil. This is based on identifying gaseous components in new and used automobile lubricants. Key compounds, so-called "signature", are separated and identified qualitatively by coupled gas chromatography/mass spectrometry. Volatile antioxidants at zero miles and fuel contaminants at low mileage are observed in the headspace of engine oil. Several oxidative degradation components have been positively identified in the used oil, which include the following: acetaldehyde, acetone, butanal, 2-propanol, acetic acid, 2-hexanol, benzoic acid, benzaldehyde, and 1-pentanol. This study strongly suggests that the status of lubricating oil can be determined by the analysis of the gas phase above the oil. Most importantly, it opens the possibility of performing conditional maintenance of the combustion engine based on information obtained from gas sensors. PMID:11305675

  11. Hydrated Electrons in a Quaternary Microemulsion System: A Pulse Radiolysis Study

    PubMed

    Adhikari; Joshi; Gopinathan

    1997-07-01

    Using the technique of pulse radiolysis, hydrated electrons have been produced and studied in quaternary microemulsion (sodium lauryl sulfate (NaLS)/water/cyclohexane/1-pentanol) system. Remarkably high lifetimes ( approximately 20 &mgr;s) for hydrated electrons have been obtained. In general, these are two orders of magnitude higher than those reported earlier in reverse micelles. The water droplet sizes and location of the probes have been determined from the decay kinetics of hydrated electrons. The yields and half-lives (t 1/2 ) of the hydrated electrons vary smoothly as the water droplet sizes are changed. We believe that these studies will be useful not only in interpreting electron transfer reactions occurring in small water pockets in biological systems but also in the production of metal nanoclusters by radiation chemical method. PMID:9241228

  12. Synthesis of Ag and AgI quantum dots in AOT-stabilized water-in-CO2 microemulsions.

    PubMed

    Liu, Juncheng; Raveendran, Poovathinthodiyil; Shervani, Zameer; Ikushima, Yutaka; Hakuta, Yukiya

    2005-03-01

    Silver and silver iodide nanocrystals have been synthesized in the water-in-CO(2) reverse microemulsions formed by the commonly used surfactant, sodium bis(2-ethylhexyl)sulfosuccinate (AOT), in the presence of 2,2,3,3,4,4,5,5-octafluoro-1-pentanol as cosurfactant. The nanometer-sized aqueous domains in the microemulsion cores not only act as nanoreactors, but the surfactant interfacial monolayer also helps the stabilization of the metal and semiconductor nanoparticles. The transmission electron microscopy results show that silver and silver iodide nanocrystals with average diameters of 6.0 nm (standard deviation, SD=1.3 nm) and 5.7 nm (SD=1.4 nm), respectively, were formed. The results indicate that the method can be utilized as a general and economically viable approach for the synthesis of metal and semiconductor quantum dots in environmentally benign supercritical carbon dioxide. PMID:15685712

  13. Light-induced oxidation in semihard cheeses. Evaluation of methods used to determine levels of oxidation.

    PubMed

    Mortensen, Grith; Sørensen, John; Stapelfeldt, Henrik

    2002-07-17

    Light-induced oxidation in Havarti cheese (38% fat) stored in the dark and exposed to fluorescent light was evaluated by an array of chemical, physical, and spectroscopic methods. Light-induced changes were noticeable already after short exposure times (<12 h). A clear differentiation between samples stored in the dark and samples exposed to 1000 lx fluorescent light was obtained by means of the following methods: color measurements (a values), peroxide value determinations, and evaluations of volatile oxidation products by solid-phase microextraction gas chromatography (SPME-GC). The expected changes in peroxide values in relation to storage time were not evident. Measuring free radicals by electron spin resonance spectrometry could not be done to distinguish between samples, possibly due to the conversion of radicals during sample preparation. However, significant light-exposure effects on secondary oxidation products, detected by SPME-GC, were noted for 1-pentanol, 1-hexanol, nonanal, and benzaldehyde. PMID:12105971

  14. Oil-in-water microemulsion globules as carriers of lipophilic substances across liquid membranes

    SciTech Connect

    Xenakis, A.; Tondre, C.

    1983-11-10

    The carrier properties of microemulsion droplets were investigated by using biphasic systems of the Winsor I type (constituted of an oil-phase floating on the top of an oil-in-water microemulsion phase). The systems investigated were constituted of sodium dodecyl sulfate/1-pentanol/n-dodecane/ (or brine). The microemulsion was used as a liquid membrane between 2 oil phases (a source phase and a receiving phase) and the rate of transfer of neutral arenes (pyrene, perylene, and anthracene), practically insoluble in the water continuous phase of the microemulsion, was determined from ultraviolet spectrophotometric measurements. The influence of different parameters on the transported solutes was studied: initial concentration of solute in the source phase, composition of the microemulsion, salt concentration. The results are shown to be consistent with a model in which the diffusion of droplets is coupled with a fast solubilization-desolubilization process and other possible mechanisms are critically examined. 32 references.

  15. Effect of five enological practices and of the general phenolic composition on fermentation-related aroma compounds in Mencia young red wines.

    PubMed

    Añón, Ana; López, Jorge F; Hernando, Diego; Orriols, Ignacio; Revilla, Eugenio; Losada, Manuel M

    2014-04-01

    The effects of five technological procedures and of the contents of total anthocyanins and condensed tannins on 19 fermentation-related aroma compounds of young red Mencia wines were studied. Multifactor ANOVA revealed that levels of those volatiles changed significantly over the length of storage in bottles and, to a lesser extent, due to other technological factors considered; total anthocyanins and condensed tannins also changed significantly as a result of the five practices assayed. Five aroma compounds possessed an odour activity value >1 in all wines, and another four in some wines. Linear correlation among volatile compounds and general phenolic composition revealed that total anthocyanins were highly related to 14 different aroma compounds. Multifactor ANOVA, considering the content of total anthocyanins as a sixth random factor, revealed that this parameter affected significantly the contents of ethyl lactate, ethyl isovalerate, 1-pentanol and ethyl octanoate. Thus, the aroma of young red Mencia wines may be affected by levels of total anthocyanins. PMID:24262556

  16. Characterization of a new mobility separation tool: HRIMS as differential mobility analyzer.

    PubMed

    Bouza, Marcos; López-Vidal, Silvia; Pisonero, Jorge; Bordel, Nerea; Pereiro, Rosario; Sanz-Medel, Alfredo

    2014-12-01

    High resolution ion mobility spectrometer (HRIMS) is a new instrument that uses parallel plate Differential Mobility Analysis as principle of separation. Gas phase analysis of volatile organic compounds (VOCs) has been performed for the characterization of this new mobility system using an UV-lamp for ionization. Studies of the effect of temperature and the presence of a desiccant are detailed. Identification of the different peaks obtained with an electrometer was successfully carried out for a group of alcohols, aromatic compounds and ketones (ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 1-heptanol, acetone, 2-butanone, 2-pentanone, 2-octanone, benzene, toluene, xylene and bromobenzene) following a modified Millikan equation. Moreover, the investigation of the discrimination capabilities within the different VOCs families as well as the mobility dependence with molecular mass was successfully achieved. PMID:25159427

  17. Optical constants of alcohols in the infrared

    NASA Technical Reports Server (NTRS)

    Sethna, P. P.; Williams, D.

    1979-01-01

    The spectral reflectances at near-normal incidence for methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol are reported for the spectral range 6700-350 kaysers. The real and imaginary parts of the complex index of refraction of these liquids are obtained in the range 4000-400 kaysers by use of Kramers-Kronig phase-shift analysis. For all of the alcohols studied, the strength for the OH-stretch bands is directly proportional to the number of OH groups per unit volume; similar relations are established for CH- and CO-stretch bands. Absorption cross sections for stretch vibrations of the three groups are considered, and the role of characteristic group intensities in intensity spectroscopy is discussed.

  18. Microemulsion systems studied by positron annihilation techniques

    SciTech Connect

    Boussaha, A.; Djermouni, B.; Fucugauchi, L.A.; Ache, H.J.

    1980-07-02

    The formation of thermalized positronium atoms is greatly reduced if increasing amounts of water become solubilized in reversed micelles formed by sodium bis(2-ethylhexyl) sulfosuccinate in apolar solvents. Similar observations have been made if the surfactant is Triton X-100. The application of the positron annihilation technique to the study of microemulsions consisting of potassium oleate-alcohol-oil-water mixtures indicates, consistent with previous results, that microemulsion formation requires a certain water/oil ratio if the oil is a long-chain aliphatic hydrocarbon such as hexadecane. This ratio is 0.4 in the case of a 1-pentanol- and 0.2 for a 1-hexanol-containing mixture. This minimum water content is strongly reduced if the oil is an aromatic hydrocarbon. The positron annihilation data also sensitively reflect structural rearrangements in these solutions occurring upon further addition of water, such as the transition of spherical aggregates to a disk-like lamellae structure.

  19. Dielectric relaxation study of mixtures of alkyl methacrylates and 1-alcohols using time-domain reflectometry

    NASA Astrophysics Data System (ADS)

    Sivagurunathan, P.; Dharmalingam, K.; Ramachandran, K.; Prabhakar Undre, B.; Khirade, P. W.; Mehrotra, S. C.

    2006-05-01

    Dielectric relaxation measurements on alkyl methacrylates (methyl methacrylate, ethyl methacrylate and butyl methacrylate) with 1-alcohols (1-propanol, 1-pentanol, 1-heptanol, 1-octanol and 1-decanol) have been carried out using time-domain reflectometry (TDR) over the frequency range 10 MHz to 20 GHz at 303 K for different concentrations of alcohols. The dielectric parameters, namely the static dielectric constant (ɛ0), the dielectric constant at microwave frequencies (ɛ∞) and the relaxation time (τ) were determined. The Kirkwood correlation factor, which contains information regarding solute-solvent interaction and corresponding structural information, the excess permittivity and the excess inverse relaxation time were also determined. The values of the static dielectric constant and the relaxation time increase with the percentage of alkyl methacrylates in the alcohol, whereas the static dielectric constant decreases and the relaxation time increases with an increase in the alkyl chain length of both the methacrylates and the alcohols.

  20. Quantum-chemical modeling of energy parameters and vibrational spectra of chain and cyclic clusters of monohydric alcohols

    NASA Astrophysics Data System (ADS)

    Golub, P.; Doroshenko, I.; Pogorelov, V.

    2014-05-01

    The specific peculiarities of alcohols such as heightened viscosity, boiling temperature and surface tension can be explained by the capability of their molecules to form relatively stable associates named clusters due to hydrogen bonding. In present work the stability of different chain-like and cyclic clusters of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-hexanol was investigated by means of quantum-chemical simulation and particular by recently developed DFT exchange-correlation functional M06-2X. The relative stability of the cluster structure was evaluated by the total energy per molecule at low temperatures (where all alcohols exist in solid state) and by the changing of the free Gibbs energy upon cluster formation at the room temperature. For the verification of revealed results the conformity of calculated IR spectra of the most stable cluster structures with the experimental IR spectra at different temperatures was analyzed.

  1. Solvent optimization for niacinamide adsorption on organo-functionalized SBA-15 mesoporous silica

    NASA Astrophysics Data System (ADS)

    Moritz, Michał

    2013-10-01

    This work describes the application of organo-modified SBA-15 siliceous materials as the carrier for niacinamide. The surface functionalization of SBA-15 by a grafting strategy with triethoxyphenylsilane, triethoxy(4-methoxyphenyl)silane, triethoxymethylsilane and (3-mercaptopropyl)trimethoxysilane as modifying agents has been successfully achieved. The adsorption process was performed in acetonitrile, methanol, 2-propanol, 1-pentanol and ethyl acetate. The obtained results indicated a promote niacinamide adsorption on sulfopropyl-modified (119 mg/g) and non-modified (78 mg/g) SBA-15 from ethyl acetate. The pure and derivatized SBA-15 products have been characterized by elemental analysis, thermogravimetry, nitrogen adsorption and diffuse reflectance UV spectroscopy. After niacinamide adsorption the textural parameters of mesoporous carriers such as BET surface area, pore volume and microporosity were reduced. The mesoporous matrices loaded with niacinamide exhibited prolonged-release kinetics of this vitamin, especially from sulfopropyl-modified SBA-15 carrier.

  2. Bioethanol Production Optimization: A Thermodynamic Analysis

    NASA Astrophysics Data System (ADS)

    Álvarez, Víctor H.; Rivera, Elmer Ccopa; Costa, Aline C.; Filho, Rubens Maciel; Maciel, Maria Regina Wolf; Aznar, Martín

    In this work, the phase equilibrium of binary mixtures for bioethanol production by continuous extractive process was studied. The process is composed of four interlinked units: fermentor, centrifuge, cell treatment unit, and flash vessel (ethanol-congener separation unit). A proposal for modeling the vapor-liquid equilibrium in binary mixtures found in the flash vessel has been considered. This approach uses the Predictive Soave-Redlich-Kwong equation of state, with original and modified molecular parameters. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. The results show that the introduction of new molecular parameters r and q in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems.

  3. Complex formation equilibria of some beta-amino-alcohols with lead(II) and cadmium(II) in aqueous solution.

    PubMed

    Canepari, S; Carunchio, V; Castellano, P; Messina, A

    1998-12-01

    A study of complex formation equilibria of some beta-amino-alcohols with lead(II) and cadmium(II) ions at 25 degrees C and in 0.5 M KNO(3) is reported. The amino-alcohols considered are 2-amino-1-propanol, 2-amino-1-butanol, 2-amino-1-pentanol and 2-amino-1,3-propanediol. sec-Buthylamine and 2-amino-1-methoxy-propane have been also considered for comparison. The results are discussed in terms of ligand structure, paying attention to the number of hydroxyl groups and to the length of the alkyl residual. A weak contribution of the alcoholic oxygen in the coordination of cadmium(II) and the presence of a mixed hydroxyl species in lead(II) containing systems are hypothesized. PMID:18967412

  4. Real-time feedback control using online attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy for continuous flow optimization and process knowledge.

    PubMed

    Skilton, Ryan A; Parrott, Andrew J; George, Michael W; Poliakoff, Martyn; Bourne, Richard A

    2013-10-01

    The use of automated continuous flow reactors is described, with real-time online Fourier transform infrared spectroscopy (FT-IR) analysis to enable rapid optimization of reaction yield using a self-optimizing feedback algorithm. This technique has been applied to the solvent-free methylation of 1-pentanol with dimethyl carbonate using a γ-alumina catalyst. Calibration of the FT-IR signal was performed using gas chromatography to enable quantification of yield over a wide variety of flow rates and temperatures. The use of FT-IR as a real-time analytical technique resulted in an order of magnitude reduction in the time and materials required compared to previous studies. This permitted a wide exploration of the parameter space to provide process understanding and validation of the optimization algorithms. PMID:24067568

  5. Enhanced solubilization and desorption of organochlorine pesticides (OCPs) from soil by oil-swollen micelles formed with a nonionic surfactant.

    PubMed

    Zheng, Guanyu; Selvam, Ammaiyappan; Wong, Jonathan W C

    2012-11-01

    The effect of oil-swollen micelles formed with nonionic surfactant polyoxyethylene sorbitan monooleate (Tween 80), cosurfactant 1-pentanol, and linseed oil on the solubilization and desorption of organochlorine pesticides (OCPs) including DDT and γ-HCH from both loam soil and clay soil were investigated. Results showed that the solubilizing capacities of oil-swollen micelles were dependent on the critical micelle concentration (CMC) of Tween 80. Once the concentrations of oil-swollen micelles exceeded the CMC of Tween 80, the oil-swollen micelles exhibited much higher solubilizing capacity than empty Tween 80 micelles for the two OCPs. Desorption tests revealed that oil-swollen micelles could successfully enhance desorption of OCPs from both loam soil and clay soil. However, compared with the efficiencies achieved by empty Tween 80 micelles, oil-swollen micelles exhibited their superiority to desorb OCPs only in loam soil-water system while was less effective in clay soil-water system. Distribution of Tween 80, 1-pentanol and linseed oil in soil-water system revealed that the difference in the sorption behavior of linseed oil onto the two soils is responsible for the different effects of oil-swollen micelles on the desorption of OCPs in loam soil and clay soil systems. Therefore, oil-swollen micelles formed with nonionic surfactant Tween 80 are better candidates over empty micelle counterparts to desorb OCPs from soil with relatively lower sorption capacity for oil fraction, which may consequently enhance the availability of OCPs in soil environment during remediation processes of contaminated soil. PMID:22998366

  6. Development and evaluation of novel sensing materials for detecting food contamination

    NASA Astrophysics Data System (ADS)

    Sankaran, Sindhuja

    Rapid detection of food-borne volatile organic compounds (VOCs) such as organic acids and alcohols released by bacterial pathogens is being used as an indicator for detecting bacterial contamination in food by our research group. One of our current research thrusts is to develop novel sensors that will be sensitive to specific compounds (at low operating temperature) associated with food safety. This study evaluates two approaches employed to develop sensors for detecting acid and alcohols at low concentrations. Chemoresistive and piezoelectric sensors were developed based on metal oxides and olfactory system based biomaterials, respectively to detect acetic acid, butanol, 3-methyl-1-butanol, 1-pentanol, and 1-hexanol. The metal oxide based sensors were developed by the sol-gel method. A zinc oxide (ZnO) sensor was found to be sensitive to acetic acid with lower detection limit ranging from 13-40 ppm. The three-layered dip-coated gold electrode based ZnO sensors had a LDL of 18 ppm for acetic acid detection. The ZnO-iron oxide (Fe2O3) based nanocomposite sensors were developed to detect butanol operating at 100°C. The 5% Fe/Zn mole ratio based ZnO-Fe2O3 nanocomposite sensors had high correlation coefficients (>0.90) of calibration curves, low butanol LDLs (26 +/- 7 ppm), and lower variation among the sensor responses. The ZnO and ZnO-Fe2O3 nanocomposite sensors showed potential to detect acetic acid and butanol at low concentrations, respectively at 100°C. QCM based olfactory sensors were developed from olfactory receptor and odorant binding protein based sequences to detect low concentrations of acetic acid and alcohols (3-methyl-1-butanol and 1-hexanol), respectively. The average LDLs for acetic acid as well as alcohols detection of the QCM sensors were < 5 ppm. The linear calibration curve based correlation coefficients of the QCM sensors were > 0.80. Finally, a computational simulation based peptide sequences was designed from olfactory receptors and

  7. Two volatile organic compounds trigger plant self-defense against a bacterial pathogen and a sucking insect in cucumber under open field conditions.

    PubMed

    Song, Geun Cheol; Ryu, Choong-Min

    2013-01-01

    Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields. PMID:23698768

  8. Electrophysiological and Behavioral Responses of Male Fall Webworm Moths (Hyphantria cunea) to Herbivory-Induced Mulberry (Morus alba) Leaf Volatiles

    PubMed Central

    Tang, Rui; Zhang, Jin Ping; Zhang, Zhong Ning

    2012-01-01

    Volatile organic compounds (VOCs) were collected from damaged and intact mulberry leaves (Morus alba L., Moraceae) and from Hyphantria cunea larvae by headspace absorption with Super Q columns. We identified their constituents using gas chromatography-mass spectrometry, and evaluated the responses of male H. cunea antennae to the compounds using gas chromatography-flame ionization detection coupled with electroantennographic detection. Eleven VOC constituents were found to stimulate antennae of male H. cunea moths: β-ocimene, hexanal, cis-3-hexenal, limonene, trans-2-hexenal, cyclohexanone, cis-2-penten-1-ol, 6-methyl-5-hepten-2-one, 4-hydroxy-4-methyl-2-pentanone, trans-3-hexen-1-ol, and 2,4-dimethyl-3-pentanol. Nine of these chemicals were released by intact, mechanically-damaged, and herbivore-damaged leaves, while cis-2-penten-1-ol was released only by intact and mechanically-damaged leaves and β-ocimene was released only by herbivore-damaged leaves. Results from wind tunnel experiments conducted with volatile components indicated that male moths were significantly more attracted to herbivory-induced volatiles than the solvent control. Furthermore, male moths' attraction to a sex pheromone lure was increased by herbivory-induced compounds and β-ocimene, but reduced by cis-2-penten-1-ol. A proof long-range field trapping experiment showed that the efficiency of sex pheromone lures in trapping male moths was increased by β-ocimene and reduced by cis-2-penten-1-ol. PMID:23166622

  9. Authentication of fattening diet of Iberian pigs according to their volatile compounds profile from raw subcutaneous fat.

    PubMed

    Narváez-Rivas, M; Pablos, F; Jurado, J M; León-Camacho, M

    2011-02-01

    The composition of volatile components of subcutaneous fat from Iberian pig has been studied. Purge and trap gas chromatography-mass spectrometry has been used. The composition of the volatile fraction of subcutaneous fat has been used for authentication purposes of different types of Iberian pig fat. Three types of this product have been considered, montanera, extensive cebo and intensive cebo. With classification purposes, several pattern recognition techniques have been applied. In order to find out possible tendencies in the sample distribution as well as the discriminant power of the variables, principal component analysis was applied as visualisation technique. Linear discriminant analysis (LDA) and soft independent modelling by class analogy (SIMCA) were used to obtain suitable classification models. LDA and SIMCA allowed the differentiation of three fattening diets by using the contents in 2,2,4,6,6-pentamethyl-heptane, m-xylene, 2,4-dimethyl-heptane, 6-methyl-tridecane, 1-methoxy-2-propanol, isopropyl alcohol, o-xylene, 3-ethyl-2,2-dimethyl-oxirane, 2,6-dimethyl-undecane, 3-methyl-3-pentanol and limonene. PMID:21072505

  10. Degradation mechanisms of geosmin and 2-MIB during UV photolysis and UV/chlorine reactions.

    PubMed

    Kim, Tae-Kyoung; Moon, Bo-Ram; Kim, Taeyeon; Kim, Moon-Kyung; Zoh, Kyung-Duk

    2016-11-01

    We conducted chlorination, UV photolysis, and UV/chlorin reactions to investigate the intermediate formation and degradation mechanisms of geosmin and 2-methylisoborneol (2-MIB) in water. Chlorination hardly removed geosmin and 2-MIB, while the UV/chlorine reaction at 254 nm completely removed geosmin and 2-MIB within 40 min and 1 h, respectively, with lesser removals of both compounds during UV photolysis. The kinetics during both UV photolysis and UV/chlorine reactions followed a pseudo first-order reaction. Chloroform was found as a chlorinated intermediate during the UV/chlorine reaction of both geosmin and 2-MIB. The pH affected both the degradation and chloroform production during the UV/chlorine reaction. The open ring and dehydration intermediates identified during UV/chlorine reactions were 1,4-dimethyl-adamantane, and 1,3-dimethyl-adamantane from geosmin, 2-methylenebornane, and 2-methyl-2-bornene from 2-MIB, respectively. Additionally, 2-methyl-3-pentanol, 2,4-dimethyl-1-heptene, 4-methyl-2-heptanone, and 1,1-dichloro-2,4-dimethyl-1-heptane were newly identified intermediates from UV/chlorine reactions of both geosmin and 2-MIB. These intermediates were degraded as the reaction progressed. We proposed possible degradation pathways during the UV photolysis and UV/chlorine reactions of both compounds using the identified intermediates. PMID:27494316

  11. Synthesis of Short-Chain Diols and Unsaturated Alcohols from Secondary Alcohol Substrates by the Rieske Nonheme Mononuclear Iron Oxygenase MdpJ

    PubMed Central

    Schäfer, Franziska; Schuster, Judith; Würz, Birgit; Härtig, Claus; Harms, Hauke; Müller, Roland H.

    2012-01-01

    The Rieske nonheme mononuclear iron oxygenase MdpJ of the fuel oxygenate-degrading bacterial strain Aquincola tertiaricarbonis L108 has been described to attack short-chain tertiary alcohols via hydroxylation and desaturation reactions. Here, we demonstrate that also short-chain secondary alcohols can be transformed by MdpJ. Wild-type cells of strain L108 converted 2-propanol and 2-butanol to 1,2-propanediol and 3-buten-2-ol, respectively, whereas an mdpJ knockout mutant did not show such activity. In addition, wild-type cells converted 3-methyl-2-butanol and 3-pentanol to the corresponding desaturation products 3-methyl-3-buten-2-ol and 1-penten-3-ol, respectively. The enzymatic hydroxylation of 2-propanol resulted in an enantiomeric excess of about 70% for the (R)-enantiomer, indicating that this reaction was favored. Likewise, desaturation of (R)-2-butanol to 3-buten-2-ol was about 2.3-fold faster than conversion of the (S)-enantiomer. The biotechnological potential of MdpJ for the synthesis of enantiopure short-chain alcohols and diols as building block chemicals is discussed. PMID:22752178

  12. Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions

    PubMed Central

    Song, Geun Cheol; Ryu, Choong-Min

    2013-01-01

    Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields. PMID:23698768

  13. Interplay of Metalloligand and Organic Ligand to Tune Micropores within Isostructural Mixed-Metal Organic Frameworks (M MOFs) for Their Highly Selective Separation of Chiral and Achiral Small Molecules

    SciTech Connect

    Madhab, Das; He, Yabing; Kim, Jaheon; Guo, Qunsheng; Zhao, Cong-Gui; Hong, Kunlun; Xiang, Sheng-Chang; Zhang, Zhangjing; Thomas, K Mark; Krishna, Rajamani; Chen, Banglin

    2012-01-01

    Four porous isostructural mixed-metal-organic frameworks (M'MOFs) have been synthesized and structurally characterized. The pores within these M'MOFs are systematically tuned by the interplay of both the metalloligands and organic ligands which have enabled us not only to direct their highly selective separation of chiral alcohols 1-phenylethanol (PEA), 2-butanol (BUT), and 2-pentanol (2-PEN) with the highest ee up to 82.4% but also to lead highly selective separation of achiral C{sub 2}H{sub 2}/C{sub 2}H{sub 4} separation. The potential application of these M'MOFs for the fixed bed pressure swing adsorption (PSA) separation of C{sub 2}H{sub 2}/C{sub 2}H{sub 4} has been further examined and compared by the transient breakthrough simulations in which the purity requirement of 40 ppm in the outlet gas can be readily fulfilled by the fixed bed M'MOF-4a adsorber at ambient conditions.

  14. Determination of trimebutine and desmethyl-trimebutine in human plasma by HPLC.

    PubMed

    Lavit, M; Saivin, S; Boudra, H; Michel, F; Martin, A; Cahiez, G; Labaune, J P; Chomard, J M; Houin, G

    2000-07-01

    A simple and sensitive HPLC method has been developed to measure trimebutine (CAS 39133-31-8, maleate: CAS 34140-59-5) and its main metabolite desmethyl-trimebutine in human plasma. The method was validated according to the Washington Consensus Conference on the Validation of Analytical Methods. It involved extraction of the plasma with n-hexane containing 2-pentanol, followed by reversed-phase HPLC using a Partisil ODS2 10 microns column and UV detection at 265 nm. The retention times of the internal standard (procaine), desmethyl-trimebutine and trimebutine were 2.4, 4.3 and 6.5 min, respectively. The standard curves were linear from 20 ng.ml-1 (limit of quantitation) to 5000 ng.ml-1 for both compounds. The coefficient of variation for all the criteria of validation were less than 15%. The extraction recoveries obtained for trimebutine and desmethyl-trimebutine were about 90%. Both compounds were very stable upon storage in plasma. The method was tested by measuring the plasma concentrations following oral administration to humans during a bioequivalence study and was shown suitable for pharmacokinetic studies. PMID:10965422

  15. The effect of oxygen on chemical dechlorination of dieldrin using iron sulphides.

    PubMed

    Hara, Junko

    2011-02-01

    The degradation of dieldrin by ferric sulphide (FeS(2)) in aqueous solution was investigated when shielded against sunlight. An oxidative dechlorination process was observed under aerobic and anaerobic conditions; oxygen volume changed the degradation rate of dieldrin and the generation rate of reaction products. The dechlorination rate under microaerophilic conditions was fastest among the anaerobic to air oxygen concentrations. For this experiment, over 99% of the dieldrin was degraded, and 90% of the released chloride was detected after 30 d under 10 μ mol oxygen. The major reaction products were different depending on the dose of oxygen. In the case of aerobic conditions, low molecular weight organic acids, such as formic acid, lactic acid, and oxalic acid, were generated as major reaction products. However, under anaerobic conditions, C(16)H(22)O(4) (dibutyl phthalate) and C(6)H(13)ClO (3-chloro-4-methyl-2-pentanol) were detected as reaction intermediates, and small amounts of succinic acid, malonic acid, and formic acid were also generated. These reactions proceed by FeS(2) interface reactions with H(2)O under anaerobic condition, or O(2) under aerobic condition. PMID:21215987

  16. Characterisation of whiskeys using solid-phase microextraction with gas chromatography-mass spectrometry.

    PubMed

    Fitzgerald, G; James, K J; MacNamara, K; Stack, M A

    2000-10-27

    The application of solid-phase microextraction and gas chromatography-mass spectrometry to the detection of flavour volatiles present in Irish and Scottish whiskeys was investigated. A method was developed to characterise these volatiles which included the extraction, identification and quantification of 17 congeners which included fusel alcohols, acetates and esters. The method validation produced the optimum fibre [85 microm poly(acrylate)], extraction time (35 min), sample volume size (3 ml) and desorption time (5 min). The impact of salt on the absorption process was also studied. Characteristic profiles were determined for each whiskey and the flavour congeners were quantified using 4-methyl-2-pentanol as the internal standard. Calibration ranges were determined for each of the congeners with coefficients of linearity ranging from 0.993 (butan-1-ol) to 0.999 (ethyl laurate) and relative standard deviations ranging from 2.5% (2-methylbutan-1-ol) to 21% (furfural) at a concentration of 18.2 mg/l. Detection limits ranged from 0.1 mg/l (ethyl caprate) to 21 mg/l (butan-2-ol). PMID:11093670

  17. Homogeneous catalysis on the gas-phase dehydration reaction of tertiary alcohols by hydrogen bromide. Density functional theory calculation

    NASA Astrophysics Data System (ADS)

    Maldonado, Alexis; Rosas, Felix; Mora, Jose R.; Brusco, Yannely; Córdova-Sintjago, Tania C.; Chuchani, Gabriel

    2015-02-01

    The gas-phase thermal dehydration mechanism of tert-butanol, 2-methyl-2-butanol, 2-methyl-2-pentanol and 2,3-dimethyl-2-butanol by homogeneous catalysis of hydrogen bromide was examined by density functional theory calculations with the hybrid functionals: M062X, CAMB3LYP and WB97XD. Reasonable agreements were found between theoretical and experimental enthalpy values at the WB97XD/6-311++G(d,p) level. The dehydration mechanism of tert-butanol with and without catalysis was evaluated in order to examine the catalyst effect on the mechanism. The elimination reaction without catalysis involves a four-membered transition state (TS), while the reaction with catalysis involves a six-membered TS. The mechanism without catalysis has enthalpy activation over 150 kJ mol-1 greater than the catalysed reaction. In all these reactions, the elongation of the C-O bond is significant in the TS. The un-catalysed reaction is controlled by breaking of C-O bond, and it was found to be more synchronous (Sy ≈ 0.91) than the hydrogen bromide catalysed reactions (Sy ≈ 0.75-0.78); the latter reactions are dominated by the three reaction coordinates associated with water formation. No significant effect on the enthalpies of activation was observed when the size of the alkyl chain was increased.

  18. Studies on the interaction between ethanol and two industrial solvents (methyl isobutyl ketone) in mice

    SciTech Connect

    Granvil, C.P.; Sharkawi, M.; Plaa, G.L. )

    1991-03-11

    Methyl n-butyl ketone (MnBK) and methyl isobutyl ketone (MiBK) prolong the duration of ethanol-induced loss of righting reflex (EILRR) in mice. MnBK was almost twice as potent in this regard. To explain this difference, the metabolism of both ketones was studied in male CD-1 mice using GC. MiBK was converted to 4-methyl-2-pentanol (4MPOL) and 4-hydroxy methyl isobutyl ketone (HMP). MnBK metabolites were 2-hexanol (2HOL) and 2,5-hexanedione (2,5HD). The effects of both ketones and metabolites on EILRR and ethanol (E) elimination were studied in mice. The ketones and their metabolites were dissolved in corn oil and injected intraperitoneally 30 min before E 4g/kg for EILRR and 2g/kg for E elimination. In the following doses: MnBK, 5; MiBK, 5; 2HOL, 2.5; 4MPOL, 2.5; and HMP 2.5, significantly prolonged EILRR. Concentrations of E in blood and brain upon return of the righting reflex were similar in solvent-treated and control animals. The mean elimination rate of E was slower in groups given MnBK or 2HOL than in control animals. No change in E elimination was observed with MiBK, HMP, 4MPOL, or 2, 5HD.

  19. Aroma composition changes in early season grapefruit juice produced from thermal concentration.

    PubMed

    Lin, Jianming; Rouseff, Russell L; Barros, Sandy; Naim, Michael

    2002-02-13

    Differences in aroma components and total volatiles between a single unpasteurized Marsh grapefruit juice and its 65 Brix concentrate reconstituted to 10 Brix were examined using GC-olfactometry (GC-O) and GC-FID. Total volatiles (FID) in the reconstituted concentrate were reduced to less than 5% of initial values, but 57% of total aroma (GC-O) remained. Forty-one aroma-active compounds were observed in unpasteurized single strength juice, whereas 27 components were found in the unflavored reconstituted concentrate. Aroma-active compounds were classified into grapefruit/sulfury, sweet/fruity, fresh/citrusy, green/fatty/metallic, and cooked/meaty groups. Five of six components in the sweet/fruity and 14 of 18 green/fatty/metallic components survived thermal concentration. However, only 4-mercapto-4-methyl-2-pentanone in the grapefruit/sulfury group, and linalool and nootkatone from the fresh/citrusy group, were found in the reconstituted concentrate. Methional was the only aroma compound in the cooked/meaty category found in both juice types. beta-Damascenone and 1-p-menthen-8-thiol were found only in the reconstituted concentrate. 4-Mercapto-4-methyl-2-pentanol was found for the first time in grapefruit juice. PMID:11829649

  20. Microemulsion-enhanced remediation of soils contaminated with organochlorine pesticides.

    PubMed

    Zhang, Yanlin; Wong, Jonathan W C; Zhao, Zhenyong; Selvam, Ammaiyappan

    2011-12-01

    Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (y-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil-surfactant-water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and gamma-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides. PMID:22439580

  1. Influence of Feeding and Controlled Dissolved Oxygen Level on the Production of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Copolymer by Cupriavidus sp. USMAA2-4 and Its Characterization.

    PubMed

    Shantini, K; Yahya, A R M; Amirul, A A

    2015-07-01

    Copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] has been the center of attention in the bio-industrial fields, as it possesses superior mechanical properties compared to poly(3-hydroxybutyrate) [P(3HB)]. The usage of oleic acid and 1-pentanol was exploited as the carbon source for the production of P(3HB-co-3HV) copolymer by using a locally isolated strain Cupriavidus sp. USMAA2-4. In this study, the productivity of polyhydroxyalkanoate (PHA) was improved by varying the frequency of feeding in fed-batch culture. The highest productivity (0.48 g/L/h) that represents 200 % increment was obtained by feeding the carbon source and nitrogen source three times and also by considering the oxygen uptake rate (OUR) and oxygen transfer rate (OTR). A significantly higher P(3HB-co-3HV) concentration of 25.7 g/L and PHA content of 66 wt% were obtained. The 3-hydroxyvalerate (3HV) monomer composition obtained was 24 mol% with the growth of 13.3 g/L. The different frequency of feeding carried out has produced a blend copolymer and has broadened the monomer distribution. In addition, increase in number of granules was also observed as the frequency of feeding increases. In general, the most glaring increment in productivity offer advantage for industrial P(3HB-co-3HV) production, and it is crucial in developing cost-effective processes for commercialization. PMID:25951779

  2. Management of postharvest grape withering to optimise the aroma of the final wine: A case study on Amarone.

    PubMed

    Bellincontro, A; Matarese, F; D'Onofrio, C; Accordini, D; Tosi, E; Mencarelli, F

    2016-12-15

    Amarone wine is different from regular dry wine due to the postharvest withering of Corvina, Corvinone and Rondinella grapes. Grapes were withered in a commercial facility with variability in terms of temperature and relative humidity (R.H.). Sugar content reached 230-240gL(-1) and 280gL(-1) at 20% and 30% mass loss, respectively. Most of VOCs (volatile organic compounds) decreased during withering but few VOCs increased during withering and we considered as markers; in Corvinone they were methylhexanoate, dimethylsuccinate, nerol, nonanoic acid, and benzyl alcohol; in Corvina, benzyl alcohol, isoamyl alcohol, 1-hexanol, p-cymen-8-ol, 2,3 pinanediol, 3-oxo-ionol and 3-methyl-1-pentanol, coumaran and damascenone; in Rondinella, hexanol, nonanoic acid, methyl vanillate, damascenone, 3-oxo-ionol, eugenol, p-cymen-8-ol, 2,3 pinanediol, coumaran and raspberry keton. Olfactive descriptors of the wines and the potential aroma of the combination of Corvina wine with the wines of the other two varieties at different percentages of mass loss are reported. PMID:27451194

  3. Production and Utilization of Ethanol by the Homoacetogen Acetobacterium woodii.

    PubMed

    Buschhorn, H; Dürre, P; Gottschalk, G

    1989-07-01

    Acetobacterium woodii formed ethanol as a fermentation product in addition to acetate when the phosphate concentration of the medium was between 0.2 and 8.4 mM. Considerable amounts of alanine were also found (2 to 11 mM). Supplementation with phosphate caused a shift to acetate as the only end product. Ethanol could also serve as a substrate for A. woodii. The fermentation yielded predominantly acetate and was strictly dependent on high bicarbonate concentrations. 1-Propanol, 1-butanol, and 1-pentanol were converted to the corresponding fatty acids but allowed only marginal growth. A. wieringae and A. carbinolicum grown under identical conditions were also able to form ethanol, and A. wieringae could use ethanol as a substrate, too. Alcohol dehydrogenase and acetaldehyde dehydrogenase activities were determined in A. woodii. Activity stains of polyacrylamide gels with crude extracts allowed the detection of acetaldehyde dehydrogenase but not of alcohol dehydrogenase. Trace amounts of methane were detected during growth of A. woodii on glucose and ethanol. PMID:16347978

  4. Characterization of the most odor-active volatiles of orange wine made from a Turkish cv. Kozan (Citrus sinensis L. Osbeck).

    PubMed

    Selli, Serkan; Canbas, Ahmet; Varlet, Vincent; Kelebek, Hasim; Prost, Carole; Serot, Thierry

    2008-01-01

    The aroma-active compounds of cv. Turkish Kozan orange wine were analyzed by sensory and instrumental analyses. Liquid-liquid extraction with dichloromethane was used for extraction of volatile components. According to sensory analysis, the aromatic extract obtained by liquid-liquid extraction was representative of orange wine odor. A total of 63 compounds were identified and quantified in orange wine. The results of the gas chromatography-olfactometry analysis showed that 35 odorous compounds were detected by the panelists. Of these, 28 aroma-active compounds were identified. Alcohols followed by terpenes and esters were the most abundant aroma-active compounds of the orange wine. Among these compounds, ethyl butanoate (fruity sweet), 3-methyl-1-pentanol (roasty), linalool (floral citrusy), gamma-butyrolactone (cheesy burnt sugar), 3-(methylthio)-propanol (boiled potato, rubber), geraniol (floral citrusy), and 2-phenylethanol (floral rose) were the most important contributors to the aroma of the orange wine because they were perceived by all eight panelists. PMID:18078317

  5. An endophyte of Picrorhiza kurroa Royle ex. Benth, producing menthol, phenylethyl alcohol and 3-hydroxypropionic acid, and other volatile organic compounds.

    PubMed

    Qadri, Masroor; Deshidi, Ramesh; Shah, Bhawal Ali; Bindu, Kushal; Vishwakarma, Ram A; Riyaz-Ul-Hassan, Syed

    2015-10-01

    An endophytic fungus, PR4 was found in nature associated with the rhizome of Picrorhiza kurroa, a high altitude medicinal plant of Kashmir Himalayas. The fungus was found to inhibit the growth of several phyto-pathogens by virtue of its volatile organic compounds (VOCs). Molecular phylogeny, based on its ITS1-5.8S-ITS2 ribosomal gene sequence, revealed the identity of the fungus as Phomopsis/Diaporthe sp. This endophyte was found to produce a unique array of VOCs, particularly, menthol, phenylethyl alcohol, (+)-isomenthol, β-phellandrene, β-bisabolene, limonene, 3-pentanone and 1-pentanol. The purification of compounds from the culture broth of PR4 led to the isolation of 3-hydroxypropionic acid (3-HPA) as a major metabolite. This is the first report of a fungal culture producing a combination of biologically and industrially important metabolites—menthol, phenylethyl alcohol, and 3-HPA. The investigation into the monoterpene biosynthetic pathway of PR4 led to the partial characterization of isopiperitenone reductase (ipr) gene, which seems to be significantly distinct from the plant homologue. The biosynthesis of plant-like-metabolites, such as menthol, is of significant academic and industrial significance. This study indicates that PR4 is a potential candidate for upscaling of menthol, phenylethyl alcohol, and 3-HPA, as well as for understanding the menthol/monoterpene biosynthetic pathway in fungi. PMID:26220851

  6. Surface Tension Characteristics of Aqueous Lithium Bromide Solution with Alcoholic Surfactant

    NASA Astrophysics Data System (ADS)

    Sasaki, Naoe; Ogawa, Kiyoshi

    At present, the combination of aqueous lithium bromide (LiBr) solution as an absorbent and water as a refrigerant have widely been used as the working fluid for absorption refrigerating machines. In order to obtain absorption enhancement of water vapor into the LiBr solution by Marangoni convection, an alcoholic surfactant is being added in the LiBr solution. In that case, the surface tension of the LiBr solution with the surfactant plays an important role for the vapor absorption. In this study, the surface tensions of the LiBr solution with several alcoholic surfactants such as 1-butanol, 1-hexanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 1-heptanol, 1-octanol and 2-ethyl-1-hexanol were measured by Wilhelmy plate method. As a result, the surface tensions of 50 wt% LiBr solution with several surfactants were obtained over the LiBr solution temperature range from 298 K to 318 K and the surfactant concentration range from 0 to 104 ppm by mass. The measured surface tension has decreased with the increasing number of carbons included in the surfactant at constant concentration, and the surface tension has increased with the increasing temperature of 50 wt% LiBr solution. The surface tension increase of 1-octanol became greater than any other surfactant used in this work. The effective carbon number of the surfactant for the absorption enhancement was in the range from 7 to 8.

  7. Alcohol action on a neuronal membrane receptor: evidence for a direct interaction with the receptor protein.

    PubMed Central

    Li, C; Peoples, R W; Weight, F F

    1994-01-01

    For almost a century, alcohols have been thought to produce their effects by actions on the membrane lipids of central nervous system neurons--the well known "lipid theory" of alcohol action. The rationale for this theory is the correlation of potency with oil/water or membrane/buffer partition coefficient. Although a number of recent studies have shown that alcohols can affect the function of certain neuronal neurotransmitter receptors, there is no evidence that the alcohols interact directly with these membrane proteins. In the present study, we report that inhibition of a neuronal neurotransmitter receptor, an ATP-gated ion channel, by a series of alcohols exhibits a distinct cutoff effect. For alcohols with a molecular volume of < or = 42.2 ml/mol, potency for inhibiting ATP-activated current was correlated with lipid solubility (order of potency: 1-propanol = trifluoroethanol > monochloroethanol > ethanol > methanol). However, despite increased lipid solubility, alcohols with a molecular volume of > or = 46.1 ml/mol (1-butanol, 1-pentanol, trichloroethanol, and dichloroethanol) were without effect on the ATP-activated current. The results suggest that alcohols inhibit the function of this neurotransmitter receptor by interacting with a small hydrophobic pocket on the receptor protein. PMID:8058780

  8. Size and Fiber Density Controlled Synthesis of Fibrous Nanosilica Spheres (KCC-1)

    PubMed Central

    Bayal, Nisha; Singh, Baljeet; Singh, Rustam; Polshettiwar, Vivek

    2016-01-01

    We report a facile protocol for the synthesis of fibrous nano-silica (KCC-1) with controllable size and fiber density. In this work, we have shown that the particle size, fiber density, surface area and pore volume of KCC-1 can be effectively controlled and tuned by changing various reaction parameters, such as the concentrations of urea, CTAB, 1-pentanol, reaction time, temperature, solvent ratio, and even outside stirring time. For the first time, we were able to control the particle size ranging from as small as 170 nm to as large as 1120 nm. We were also able to control the fiber density from low to medium to very dense, which consequently allowed the tuning of the pore volume. We were able to achieve a pore volume of 2.18 cm3/g, which is the highest reported for such a fibrous material. Notably we were even able to increase the surface area up to 1244 m2/g, nearly double the previously reported surface area of KCC-1. Thus, one can now synthesize KCC-1 with various degrees of size, surface area, pore volume, and fiber density. PMID:27118152

  9. Effect of Fresh Garlic on Lipid Oxidation and Microbiological Changes of Pork Patties during Refrigerated Storage

    PubMed Central

    2014-01-01

    The effects of two levels (1.4 vs 2.8%) of fresh garlic on lipid oxidation and microbial growth in pork patties were evaluated. Hunter color (L, a, b), pH, thiobarbituric acid reactive substances (TBARS), oxidative volatile compounds, total bacteria and Enterobacteriaceae in the pork patties with or without fresh garlic were measured during storage at 4℃. Addition of fresh garlic decreased redness (a), while increased pH and yellowness (b) values of the fresh pork patties were observed, regardless of the levels added. The TBARS values of the pork patties were increased with the addition of fresh garlic (p<0.05). Similar results were observed in oxidative volatile compounds. A total of 13 volatile compounds were detected in the patties (5 sulfur-containing compounds, including allyl mercaptan, allyl methyl sulfide, diallyl sulfide, methyl-(E)-propenyl-disulfide, and diallyl disulfide, and the 8 other oxidative compounds, including 1-pentanol, hexanal, 1-hexanol, heptanal, (E)-2-heptenal, 1-octen-3-ol, (E)-2-octenal and nonanal). Fresh garlic accelerated development of oxidative products in the pork patties, especially hexanal and the total oxidative volatile compounds. However, the addition of 1.4 and 2.8% of fresh garlic inhibited the growth of total bacteria and Enterobacteriaceae, indicating low total bacterial counts and Enterobacteriaceae than the controls. PMID:26761498

  10. Effect of paper porosity on OCT images: Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Kirillin, Mikhail Yu.; Priezzhev, Alexander V.; Myllylä, Risto

    2008-06-01

    Non-invasive measurement of paper porosity is an important problem for papermaking industry. Presently used techniques are invasive and require long time for processing the sample. In recent years optical coherence tomography (OCT) has been proved to be an effective tool for non-invasive study of optically non-uniform scattering media including paper. The aim of present work is to study the potential ability of OCT for sensing the porosity of a paper sample by means of numerical simulations. The paper sample is characterized by variation of porosity along the sample while numerical simulations allow one to consider the samples with constant porosity which is useful for evaluation of the technique abilities. The calculations were performed implementing Monte Carlo-based technique developed earlier for simulation of OCT signals from multilayer paper models. A 9-layer model of paper consisting of five fiber layers and four air layers with non-planar boundaries was considered. The porosity of the samples was varied from 30 to 80% by varying the thicknesses of the layers. The simulations were performed for model paper samples without and with optical clearing agents (benzyl alcohol, 1-pentanol, isopropanol) applied. It was shown that the simulated OCT images of model paper with various porosities significantly differ revealing the potentiality of the OCT technique for sensing the porosity. When obtaining the images of paper samples with optical clearing agents applied, the inner structure of the samples is also revealed providing additional information about the samples under study.

  11. On the Investigation of Coarse-Grained Models for Water: Balancing Computational Efficiency and the Retention of Structural Properties

    PubMed Central

    Hadley, Kevin R.; McCabe, Clare

    2010-01-01

    Developing accurate models of water for use in computer simulations is important for the study of many chemical and biological systems, including lipid bilayer self-assembly. The large temporal and spatial scales needed to study such self-assembly have led to the development and application of coarse-grained models for the lipid-lipid, lipid-solvent and solvent-solvent interactions. Unfortunately, popular center-of-mass-based coarse-graining techniques are limited to modeling water with one-water per bead. In this work, we have utilized the K-means algorithm to determine the optimal clustering of waters to allow the mapping of multiple waters to single coarse-grained beads. Through the study of a simple mixture between water and an amphiphilic solute (1-pentanol), we find a 4-water bead model has the optimal balance between computational efficiency and accurate solvation and structural properties when compared to water models ranging from 1 to 9 waters per bead. The 4-water model was subsequently utilized in studies of the solvation of hexadecanoic acid and the structure, as measured via radial distribution functions, for the hydrophobic tails and the bulk water phase were found to agree well with experimental data and their atomistic targets. PMID:20230012

  12. Synthesis and chemical modifications of in-situ grown anatase TiO2 microspheres with isotropically exposed {0 0 1} facets for superhydrophobic and self-cleaning properties

    NASA Astrophysics Data System (ADS)

    Hu, Wanbiao; Yu, Yuanlie; Chen, Hua; Lau, Kenny; Craig, Vincent; Brink, Frank; Withers, Ray L.; Liu, Yun

    2015-12-01

    Excellent and robust hydrophobic materials generally benefit from specifically exposed surfaces i.e. always the low-energy surfaces, and well-defined micro/nano-structures that are achieved through advanced facilities and complicated process with a high cost. We hereof demonstrate that the superhydrophobicity and further self-cleaning properties are also attainable based on high-energy crystalline facets by an appropriate chemical modification. Specifically, anatase TiO2 microspheres were large-scale synthesized to exhibit isotropically exposed high-energy {0 0 1} facets through optimizing the HF/H2O2/H2O ratio during hydrothermal processes. The formation of the microspheres was uncovered to be an in-situ "growth-cum-assembly" grown mechanism. Such high-energy {0 0 1} facets facilitate the strong coupling between the resultant TiO2 microspheres and the modifier (2,2,3,3,4,4,5,5-octafluoro-1-pentanol) because the {0 0 1} facets offer abundant active sites for chemical bonding, showing great merits for superhydrophobicity (with water contact angle of 154 ± 2°, 6 μl droplets), and further stably surface self-cleaning i.e. easily removing surface contamination (e.g. Al2O3 powders). This integrated strategy represents a milestone in design and fabrication of delicate composites with high-energy surfaces for specific functions and properties.

  13. Phase separation phenomena of polysulfone/solvent/organic nonsolvent and polyethersulfone/solvent/organic nonsolvent systems

    SciTech Connect

    Wang, Dongliang; Li, K.; Sourirajan, S.; Teo, W.K. . Dept. of Chemical Engineering)

    1993-12-10

    The precipitation values (PVs) of several organic nonsolvents in polysulfone (PSf)/solvent and polyethersulfone (PESf)/solvent systems were measured in temperatures ranging from 10 to 80 C by the direct titration method and compared with those of water in the same systems. The solvents used were N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAC); the organic nonsolvents employed were methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, ethylene glycol, and diethylene glycol as well as acetic acid and propionic acid. The compositions of nonsolvent, polymer, and solvent at the precipitation points for different polymer concentrations up to 10 wt% were also determined at 30 C with respect to both the polymers and six nonsolvents presented. These results were used to obtain the polymer precipitation curves in the polymer-solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent for a polymer. The effect of temperature on the precipitation value was observed to be dramatically different for different polymer/solvent/nonsolvent systems. These results were explained on the basis of polar and nonpolar interactions of the polymer, solvent, and nonsolvent system.

  14. Rapid ester biosynthesis screening reveals a high activity alcohol-O-acyltransferase (AATase) from tomato fruit.

    PubMed

    Lin, Jyun-Liang; Zhu, Jie; Wheeldon, Ian

    2016-05-01

    Ethyl and acetate esters are naturally produced in various yeasts, plants, and bacteria. The biosynthetic pathways that produce these esters share a common reaction step, the condensation of acetyl/acyl-CoA with an alcohol by alcohol-O-acetyl/acyltransferase (AATase). Recent metabolic engineering efforts exploit AATase activity to produce fatty acid ethyl esters as potential diesel fuel replacements as well as short- and medium-chain volatile esters as fragrance and flavor compounds. These efforts have been limited by the lack of a rapid screen to quantify ester biosynthesis. Enzyme engineering efforts have also been limited by the lack of a high throughput screen for AATase activity. Here, we developed a high throughput assay for AATase activity and used this assay to discover a high activity AATase from tomato fruit, Solanum lycopersicum (Atf-S.l). Atf1-S.l exhibited broad specificity towards acyl-CoAs with chain length from C4 to C10 and was specific towards 1-pentanol. The AATase screen also revealed new acyl-CoA substrate specificities for Atf1, Atf2, Eht1, and Eeb1 from Saccharomyces cerevisiae, and Atf-C.m from melon fruit, Cucumis melo, thus increasing the pool of characterized AATases that can be used in ester biosynthesis of ester-based fragrance and flavor compounds as well as fatty acid ethyl ester biofuels. PMID:26814045

  15. Volatile Compounds Originating from Mixed Microbial Cultures on Building Materials under Various Humidity Conditions

    PubMed Central

    Korpi, Anne; Pasanen, Anna-Liisa; Pasanen, Pertti

    1998-01-01

    We examined growth of mixed microbial cultures (13 fungal species and one actinomycete species) and production of volatile compounds (VOCs) in typical building materials in outside walls, separating walls, and bathroom floors at various relative humidities (RHs) of air. Air samples from incubation chambers were adsorbed on Tenax TA and dinitrophenylhydrazine cartridges and were analyzed by thermal desorption-gas chromatography and high-performance liquid chromatography, respectively. Metabolic activity was measured by determining CO2 production, and microbial concentrations were determined by a dilution plate method. At 80 to 82% RH, CO2 production did not indicate that microbial activity occurred, and only 10% of the spores germinated, while slight increases in the concentrations of some VOCs were detected. All of the parameters showed that microbial activity occurred at 90 to 99% RH. The microbiological analyses revealed weak microbial growth even under drying conditions (32 to 33% RH). The main VOCs produced on the building materials studied were 3-methyl-1-butanol, 1-pentanol, 1-hexanol, and 1-octen-3-ol. In some cases fungal growth decreased aldehyde emissions. We found that various VOCs accompany microbial activity but that no single VOC is a reliable indicator of biocontamination in building materials. PMID:9687450

  16. Fractionation and identification of minor and aroma-active constituents in Kangra orthodox black tea.

    PubMed

    Joshi, Robin; Gulati, Ashu

    2015-01-15

    The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography-olfactometry-mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, β-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography-olfactometry-mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, β-ionone, hotrienol and dihydroactinidiolide to be odour active components. PMID:25148991

  17. Novel isoquinoline derivatives as antimicrobial agents.

    PubMed

    Galán, Abraham; Moreno, Laura; Párraga, Javier; Serrano, Ángel; Sanz, Ma Jesús; Cortes, Diego; Cabedo, Nuria

    2013-06-01

    The wide variety of potent biological activities of natural and synthetic isoquinoline alkaloids encouraged us to develop novel antimicrobial isoquinoline compounds. We synthesized a variety of differently functionalized 1-pentyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (THIQs), including dihydroisoquinolinium salts (2 and 5), methyl pentanoate-THIQ (6), 1-pentanol-THIQ (7), ester derivatives (8-15) and carbamate derivatives (16-23). We employed classic intramolecular Bischler-Napieralski cyclodehydration to generate the isoquinoline core. All the structures were characterized by nuclear magnetic resonance and mass spectrometry. The bactericide and fungicide activities were evaluated for all the synthesized compounds and structure-activity relationships were established. Many compounds exhibited high and broad-range bactericidal activity. Fluorophenylpropanoate ester 13 and the halogenated phenyl- (17, 18) and phenethyl carbamates (21, 22) exerted the most remarkable bactericidal activity. However, few compounds displayed antifungal activity against most of the fungi tested. Among them, chlorinated derivatives like chlorobenzoate and chlorophenylpropanoate esters (10 and 14, respectively) and chlorophenethyl carbamate 22, exhibited the greatest antifungal activity. PMID:23601815

  18. Dielectric barrier discharge carbon atomic emission spectrometer: universal GC detector for volatile carbon-containing compounds.

    PubMed

    Han, Bingjun; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

    2014-01-01

    It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 °C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures. PMID:24328147

  19. Nucleation of ethanol, propanol, butanol, and pentanol: A systematic experimental study along the homologous series

    NASA Astrophysics Data System (ADS)

    Manka, Alexandra A.; Wedekind, Jan; Ghosh, David; Höhler, Kristina; Wölk, Judith; Strey, Reinhard

    2012-08-01

    We present homogeneous vapor-liquid nucleation rates of the 1-alcohols (CnH2n+1OH, n = 2-4) measured in the well-established two-valve nucleation pulse chamber as well as in a novel one-piston nucleation pulse chamber at temperatures between 235 and 265 K. The nucleation rates and critical cluster sizes show a very systematic behavior with respect to the hydrocarbon chain length of the alcohol, just as their thermo-physical parameters such as surface tension, vapor pressure, and density would suggest. For all alcohols, except ethanol, predictions of classical nucleation theory lie several orders of magnitude below the experimental results and show a strong temperature-dependence typically found in nucleation experiments. The more recent Reguera-Reiss theory [J. Phys. Chem. B 108(51), 19831 (2004)] achieves reasonably good predictions for 1-propanol, 1-butanol, and 1-pentanol, and independent of the temperature. Ethanol, however, clearly shows the influence of strong association between molecules even in the vapor phase. We also scaled all experimental results with classic nucleation theory to compare our data with other data from the literature. We find the same overall temperature trend for all measurement series together but inverted and inconsistent temperature trends for individual 1-propanol and 1-butanol measurements in other devices. Overall, our data establishe a comprehensive and reliable data set that forms an ideal basis for comparison with nucleation theory.

  20. Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent

    NASA Astrophysics Data System (ADS)

    Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin

    2008-02-01

    Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

  1. Use of micellar liquid chromatography for rapid monitoring of fungicides post harvest applied to citrus wastewater.

    PubMed

    Peris-Vicente, Juan; Marzo-Mas, Ana; Roca-Genovés, Pasqual; Carda-Broch, Samuel; Esteve-Romero, Josep

    2016-04-01

    A method based on micellar liquid chromatography has been developed to simultaneously monitor four pesticides largely post-harvest applied to citrus: thiabendazole, pyrimethanil, o-phenylphenol and imazalil. Water samples were filtered and directly injected without other treatment, thus avoiding extraction steps. The composition of the mobile phase was optimized using a chemometrical approach to achieve and excellent resolution to 0.07mol/L SDS/5%, V/V 1-pentanol buffered at pH3. Mobile phase run through a C18 column at 1mL/min at room temperature. The detection was performing by UV-Visible absorbance using a wavelength program: 0-10min, 305nm (for thiabendazole); 10-12; 265nm (for pyrimethanil) and 12-18, 220nm (o-phenylphenol and imazalil). The developed method was validated following the guidelines of the US Environmental Protection Agency in terms of: quantitation range, (0.5-4 to 15μg/mL), linearity (r(2)>0.9995), sensitivity (LOD, 0.18-1.4μg/mL), precision (<9.2%), trueness (93.9%-103.7%), and ruggedness (<9.9%). It was found that the fungicides remain up to eight days in surface water at outdoor conditions. The method was used to screen the presence of the analytes in several waste water samples, and was proved to be useful in routine analysis. PMID:27090721

  2. Size and Fiber Density Controlled Synthesis of Fibrous Nanosilica Spheres (KCC-1)

    NASA Astrophysics Data System (ADS)

    Bayal, Nisha; Singh, Baljeet; Singh, Rustam; Polshettiwar, Vivek

    2016-04-01

    We report a facile protocol for the synthesis of fibrous nano-silica (KCC-1) with controllable size and fiber density. In this work, we have shown that the particle size, fiber density, surface area and pore volume of KCC-1 can be effectively controlled and tuned by changing various reaction parameters, such as the concentrations of urea, CTAB, 1-pentanol, reaction time, temperature, solvent ratio, and even outside stirring time. For the first time, we were able to control the particle size ranging from as small as 170 nm to as large as 1120 nm. We were also able to control the fiber density from low to medium to very dense, which consequently allowed the tuning of the pore volume. We were able to achieve a pore volume of 2.18 cm3/g, which is the highest reported for such a fibrous material. Notably we were even able to increase the surface area up to 1244 m2/g, nearly double the previously reported surface area of KCC-1. Thus, one can now synthesize KCC-1 with various degrees of size, surface area, pore volume, and fiber density.

  3. Olfactory discrimination of structurally similar alcohols by cockroaches.

    PubMed

    Sakura, M; Okada, R; Mizunami, M

    2002-11-01

    The capability of the cockroach Periplaneta americana to discriminate odors of structurally similar aliphatic alcohols was studied by using an operant conditioning paradigm. Cockroaches were trained to discriminate three odors: one odor associated with sucrose solution (reward) and two odors associated with NaCl solution (non-reward). After training, their odor preferences were tested by counting the number of visits to each odor source. We tested the capability of cockroaches to discriminate (1) three normal aliphatic alcohols with different numbers of carbon (1-pentanol, 1-hexanol and 1-octanol), (2) three C6 aliphatic alcohols (1-hexanol, 2-hexanol and trans-2-hexen-1-ol), (3) binary mixtures of two of these three alcohols and their components, and (4) 1-hexanol solution of three different concentrations (1, 10 and 100 micro g micro l(-1)). Cockroaches exhibited higher preferences for the odors associated with reward in these tests, and we therefore conclude that cockroaches can discriminate these odors. However, discrimination of 1-hexanol and trans-2-hexen-1-ol and their binary mixture was imperfect, in that some statistical tests suggested significant level of discrimination but other tests did not. In addition, the cockroaches learned to associate a 1-hexanol solution of the highest or lowest concentration with sucrose reward but failed to learn to associate 1-hexanol of an intermediate concentration with reward. PMID:12466954

  4. Gas-liquid solubilities of carbon monoxide, carbon dioxide, hydrogen, water, 1-alcohols (1 [<=] n [<=] 6), and n-paraffins (2 [<=] n [<=] 6) in hexadecane, octacosane, 1-hexadecanol, phenanthrene, and tetraethylene glycol at pressures up to 5. 5 MPa and temperatures from 293 to 553 K

    SciTech Connect

    Breman, B.B.; Beenackers, A.A.C.M.; Rietjens, E.W.J.; Stege, R.J.H. . Dept. of Chemical Engineering)

    1994-10-01

    At temperatures between 473 and 673 K and pressures between 2 and 10 MPa, synthesis gas can be converted toward methanol, fuel-methanol (a mixture of methanol and higher alcohols), or a mixture of hydrocarbons (Fischer-Tropsch synthesis), depending on the type of heterogeneous catalyst applied. The gas-liquid solubilities of the solutes carbon monoxide, carbon dioxide, hydrogen, water, ethane, propane, pentane, hexane, methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol in the solvents tetraethylene glycol, hexadecane, octacosane, 1-hexadecanol, and phenanthrene were measured as a function of temperature. The solutes are all reactants or products relevant for synthesis gas conversion into alcohols and/or hydrocarbons. The solvents are seen as potentially attractive for synthesis gas conversion via gas-slurry processes. Experimental conditions varied between 293 and 553 K and 0.06 and 5.5 MPa, covering typical process conditions for synthesis gas conversion. The total set of experimental results consists of 1,533 gas-liquid solubilities divided over 60 binary systems. As far as the authors know hardly any of the gas-liquid solubilities from this set have been reported previously in the literature. Where literature data are available, a comparison is made with their data. This comparison always shows an agreement within the calculated experimental errors with an average deviation of 7.6% and a maximal deviation of 15.0%.

  5. Occurrence and behavior of system peaks in RP HPLC with solely aqueous mobile phases.

    PubMed

    Kalíková, Kveta; Hruska, Vlastimil; Svobodová, Jana; Chudoba, Richard; Gas, Bohuslav; Tesarová, Eva

    2009-09-01

    System peaks are important but often also disturbing phenomena occurring in separation systems. Behavior of system peaks was studied in reversed phase high performance liquid chromatography (RP HPLC) systems consisting of an RP Amide C16 column and aqueous solutions of organic acids with alkaline metal hydroxides as mobile phases. Binary mobile phases, composed of benzoic acid and lithium hydroxide (LiOH) or cesium hydroxide (CsOH), yielded two system peaks. The first peak was stationary and the second one moved with dilution of the mobile phase or with changes of the alkaline metal hydroxide concentration. The latter changes affected dissociation of the benzoic acid present in the mobile phase and thereby its retention. The presumption that the first system peak is not influenced by the type of alkaline metal cation and that it is related to the non-adsorbed component of the mobile phase was confirmed by a cyclic procedure. Three-component mobile phases composed of benzoic acid, tropic acid, and a hydroxide gave rise to three system peaks as expected. The first peak was again stationary and the two others shifted depending on the concentration variation of both acids. Resonance causing a zigzag peak, well described in capillary zone electrophoresis (CZE), was observed if 1-pentanol was injected into a chromatographic system with one-component mobile phase. PMID:19639550

  6. A direct passive method for measuring water and contaminant fluxes in porous media

    NASA Astrophysics Data System (ADS)

    Hatfield, Kirk; Annable, Michael; Cho, Jaehyun; Rao, P. S. C.; Klammler, Harald

    2004-12-01

    This paper introduces a new direct method for measuring water and contaminant fluxes in porous media. The method uses a passive flux meter (PFM), which is essentially a self-contained permeable unit properly sized to fit tightly in a screened well or boring. The meter is designed to accommodate a mixed medium of hydrophobic and/or hydrophilic permeable sorbents, which retain dissolved organic/inorganic contaminants present in the groundwater flowing passively through the meter. The contaminant mass intercepted and retained on the sorbent is used to quantify cumulative contaminant mass flux. The sorptive matrix is also impregnated with known amounts of one or more water soluble 'resident tracers'. These tracers are displaced from the sorbent at rates proportional to the groundwater flux; hence, in the current meter design, the resident tracers are used to quantify cumulative groundwater flux. Theory is presented and quantitative tools are developed to interpret the water flux from tracers possessing linear and nonlinear elution profiles. The same theory is extended to derive functional relationships useful for quantifying cumulative contaminant mass flux. To validate theory and demonstrate the passive flux meter, results of multiple box-aquifer experiments are presented and discussed. From these experiments, it is seen that accurate water flux measurements are obtained when the tracer used in calculations resides in the meter at levels representing 20 to 70 percent of the initial condition. 2,4-Dimethyl-3-pentanol (DMP) is used as a surrogate groundwater contaminant in the box aquifer experiments. Cumulative DMP fluxes are measured within 5% of known fluxes. The accuracy of these estimates generally increases with the total volume of water intercepted.

  7. Contribution of liver alcohol dehydrogenase to metabolism of alcohols in rats.

    PubMed

    Plapp, Bryce V; Leidal, Kevin G; Murch, Bruce P; Green, David W

    2015-06-01

    The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5-20 mmol/kg. Ethanol was eliminated most rapidly, at 7.9 mmol/kgh. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5-10 mmol/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmol/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6±1 mmol/kg h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD(+) for the conversion to ketones whereas primary alcohols require two equivalents of NAD(+) for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD(+) is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189

  8. Can volatile organic metabolites be used to simultaneously assess microbial and mite contamination level in cereal grains and coffee beans?

    PubMed

    Salvador, Angelo C; Baptista, Inês; Barros, António S; Gomes, Newton C M; Cunha, Angela; Almeida, Adelaide; Rocha, Silvia M

    2013-01-01

    A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC-ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC-ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans. PMID:23613710

  9. Can Volatile Organic Metabolites Be Used to Simultaneously Assess Microbial and Mite Contamination Level in Cereal Grains and Coffee Beans?

    PubMed Central

    Salvador, Ângelo C.; Baptista, Inês; Barros, António S.; Gomes, Newton C. M.; Cunha, Ângela; Almeida, Adelaide; Rocha, Silvia M.

    2013-01-01

    A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC–ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC–ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans. PMID:23613710

  10. Bacterial Degradation of tert-Amyl Alcohol Proceeds via Hemiterpene 2-Methyl-3-Buten-2-ol by Employing the Tertiary Alcohol Desaturase Function of the Rieske Nonheme Mononuclear Iron Oxygenase MdpJ

    PubMed Central

    Schuster, Judith; Schäfer, Franziska; Hübler, Nora; Brandt, Anne; Rosell, Mònica; Härtig, Claus; Harms, Hauke; Müller, Roland H.

    2012-01-01

    Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed. PMID:22194447

  11. High extraction efficiency fiber coated with calix[4] open-chain crown ether for solid-phase microextraction of polar aromatic and aliphatic compounds.

    PubMed

    Liu, Mingming; Zeng, Zhaorui; Lei, Yun; Li, Haibing

    2005-11-01

    The calix[4] open-chain crown ether, 5,11,17,23-tetra-tert-butyl-25,27-di(2-allyloxyethoxyl)-26,28-dihydroxycalix[4]arene was synthesized and used for preparation of solid-phase microextraction (SPME) fibers of enhanced extraction efficiency. The new SPME coating made from calix[4] open-chain crown ether and hydroxyl-terminated silicone oil was developed with the aid of vinyltriethoxylsilane as bridge using sol-gel method and cross-linking technology. The efficiency of the novel fiber in the extraction of polar aromatic and aliphatic compounds, such as phenols, alcohols, and volatile fatty acids, was also investigated. Due to the introduction of the polar open-chain crown ether in calix[4]arene molecules, the calix[4] open-chain crown ether fiber showed much better selectivity and sensitivity to these polar compounds in comparison with calix[4]arene fiber. It also had superior extraction efficiency when compared to commercial poly(dimethylsiloxane)-divinylbenzene and polyacrylate fibers. Parts per billion to parts per trillion level detection limits were achieved for most of the analytes through SPME in conjunction with GC and flame ionization detector. The linear ranges were two to four orders of magnitude, and the RSD values were below 7% for all analytes. The novel fiber was applied to determine volatile alcohols and fatty acids in wine samples. The volatile-free wine prepared in this work was used to assure similar chemical environment for analytes in both calibration solutions and in real wine samples, thus compensating for possible matrix interferences. The established internal standard method using 4-methyl-2-pentanol as internal standard showed satisfactory accuracy and precision. PMID:16342796

  12. Topical delivery of hexamidine.

    PubMed

    Parisi, Nicola; Paz-Alvarez, Miguel; Matts, Paul J; Lever, Rebecca; Hadgraft, Jonathan; Lane, Majella E

    2016-06-15

    Hexamidine diisethionate (HEX D) has been used for its biocidal actions in topical preparations since the 1950s. Recent data also suggest that it plays a beneficial role in skin homeostasis. To date, the extent to which this compound penetrates the epidermis has not been reported nor how its topical delivery may be modulated. In the present work we set out to characterise the interaction of HEX D with the skin and to develop a range of simple formulations for topical targeting of the active. A further objective was to compare the skin penetration of HEX D with its corresponding dihydrochloride salt (HEX H) as the latter has more favourable physicochemical properties for skin uptake. Candidate vehicles were evaluated by in vitro Franz cell permeation studies using porcine skin. Initially, neat solvents were investigated and subsequently binary systems were examined. The solvents and chemical penetration enhancers investigated included glycerol, dimethyl isosorbide (DMI), isopropyl alcohol (IPA), 1,2-pentanol (1,2-PENT), polyethylene glycol (PEG) 200, propylene glycol (PG), propylene glycol monolaurate (PGML) and Transcutol(®)P (TC). Of a total of 30 binary solvent systems evaluated only 10 delivered higher amounts of active into the skin compared with the neat solvents. In terms of topical efficacy, formulations containing PGML far surpassed all other solvents or binary combinations. More than 70% of HEX H was extracted from the skin following application in PG:PGML (50:50). Interestingly, the same vehicle effectively promoted skin penetration of HEX D but demonstrated significantly lower uptake into and through the skin (30%). The findings confirm the unpredictable nature of excipients on delivery of actives with reference to skin even where there are minor differences in molecular structures. We also believe that they underline the ongoing necessity for fundamental studies on the interaction of topical excipients with the skin. PMID:27130367

  13. Phenolic and volatile compounds of extra virgin olive oil (Olea europaea L. Cv. Cornicabra) with regard to fruit ripening and irrigation management.

    PubMed

    Gómez-Rico, Aurora; Salvador, M Desamparados; La Greca, Marta; Fregapane, Giuseppe

    2006-09-20

    This study investigated the effect of both the degree of ripening of the olive fruit and irrigation management-rain-fed, two different regulated deficit irrigations (RDI), the method proposed by the Food and Agriculture Organization of the United Nations (known as FAO), and 125 FAO (125% FAO)-on the phenolic and volatile composition of Cornicabra virgin olive oils obtained during two crop seasons. Secoiridoid phenolic derivatives greatly decreased upon increase of both irrigation and ripening, for example, the 3,4-DHPEA-EDA content decreased from 770 to 450 mg/kg through fruit ripening under rain-fed conditions and from 676 to 388 mg/kg from rain-fed conditions to FAO irrigation treatment (at a ripeness index of approximately 4). Moreover, secoiridoid derivatives of hydroxytyrosol decreased more than those of tyrosol. The levels of major volatile components decreased in the course of ripening but were higher in irrigated olive oils: for example, the E-2-hexenal content ranged between 4.2 and 2.6 mg/kg (expressed as 4-methyl-2-pentanol) over fruit maturation under rain-fed conditions and between 8.0 and 3.5 mg/kg under FAO scheduling. It is important to note that where water was applied only from the beginning of August (RDI-2), when oil begins to accumulate in the fruit, the resulting virgin olive oil presented a phenol and volatile profile similar to those of the FAO and 125 FAO methods, but with a considerable reduction in the amount of water supplied to the olive orchard. PMID:16968073

  14. Comparative study of aromatic compounds in fruit wines from raspberry, strawberry, and mulberry in central Shaanxi area

    PubMed Central

    Feng, Yiming; Liu, Min; Ouyang, Yanan; Zhao, Xianfang; Ju, Yanlun; Fang, Yulin

    2015-01-01

    Background Although grape wines have firmly dominated the production and consumption markets of fruit wines, raspberry, strawberry, and mulberry have been utilized to make wines because of their joyful aroma and high contents of polyphenolic phytochemicals and essential fatty acids. However, little is known about aromatic compounds of the wines produced from these three fruits. Methods The aromatic composition of fruit wines produced from raspberry, strawberry, mulberry, and red grape was analyzed by GC-MS. Odor activity values (OAVs) and relative odor contributions (ROCs) were used to estimate the sensory contribution of the aromatic compounds to the overall flavor of the wines. Results In strawberry, raspberry, and mulberry wines, 27, 30, and 31 odorants were detected, respectively. Alcohols formed the most abundant group, followed by esters and acids. The grape wine contained a wider variety (16 types) of alcohols, and 4-methyl-2-pentanol and 2,3-butanediol were not present in the three fruit wines. The quantity of esters in raspberry (1.54%) and mulberry wines (2.08%) were higher than those of strawberry wine (0.78%), and mulberry wine contained more types of esters. There were no significant differences of acids between the three fruit wines and the control wine. In addition, 2-heptanone, 2-octanone, 2-nonanone, and 2-undecanone were unique to raspberry wine, and nonanal was present only in mulberry wine. The indistinguishable aroma of the three fruit wines was attributed to the dominance of fruity and floral odor components derived from ethyl esters of fatty acids and their contributions to the global aroma of the three fruit wines. Conclusion The present study demonstrated that there were significant differences in the volatile components of fruit wines made from raspberry, strawberry, and mulberry. The aroma compounds were more abundant in the raspberry and mulberry wines than in the strawberry wine, but the quality of strawberry wine was superior to

  15. Development of a standard gas generating vial comprised of a silicon oil-polystyrene/divinylbenzene composite sorbent.

    PubMed

    Grandy, Jonathan J; Gómez-Ríos, German A; Pawliszyn, Janusz

    2015-09-01

    In this work, a highly reproducible standard gas generating vial is proposed. The vial is comprised of a silicon diffusion pump oil spiked with an appropriate calibration compound, such as modified McReynolds probes (benzene, 2-pentanone, pyridine, 1-nitropropane, 1-pentanol, and n-octane), and then mixed with polystyrene/divinylbenzene (PS/DVB) particles. The concentrations of these compounds in gaseous headspace were found to substantially decrease in comparison to previously developed hydrocarbon pump oil based vials; hence, the amount of standard loaded onto SPME fibers was at most, half that of the previous vial design. Depletion for all compounds after 208 successive extractions was shown to be less than 3.5%. Smaller quantities of standards being used resulted in a vial that depleted slower while remaining statistically repeatable over a wider number of runs. Indeed, it was found that depletion could be largely predicted by using a mass balance theoretical model. This behavior allowed a further increase in the number of loadings that could be performed repeatedly. At a 95% level of confidence, the ANOVA test demonstrated that the prepared vials were statistically identical, with no significant intra- or inter-batch differences. In addition, it was found that vials stored under different conditions (e.g. under light exposure, room temperature, and within a refrigerator) were stable over 10 weeks. Silicon based vials proved to be ideal for performing instrument quality control and loading of internal standards onto fibers, both of which are of great importance when performing on-site analysis using portable GC-MS instrumentation and high throughput determinations in laboratory. PMID:26243704

  16. Role of non-ionic surfactants and plant oils on the solubilization of organochlorine pesticides by oil-in-water microemulsions.

    PubMed

    Zheng, Guanyu; Zhao, Zhenyong; Wong, Jonathan W C

    2011-01-01

    Screening low-cost, high efficacy and environmentally safe surface active agents is critical for achieving successful surfactant-enhanced remediation (SER) of soil contaminated with hydrophobic organic compounds. This study reports the solubilization of organochlorine pesticides (DDT or gamma-HCH) in oil-in-water (Winsor I) microemulsions (microE) composed of non-ionic surfactant (Tween 80 or Triton X-100), plant oil (linseed oil or soybean oil), and the cosurfactant (1-pentanol). Results show that the cosurfactant to surfactant ratio (C/S ratio, w/w) is the major factor influencing the microemulsion formation, and C/S ratios of 1:3 and 1:6 are superior to 1:1 for microemulsion formation. 66.9-95.6% and 51.9-80.9% of DDT solubilization enhancements were achieved by microemulsions based respectively on Tween 80 or Triton X-100 as compared to their respective surfactant solution alone, indicating the higher solubilizing capacities of microemulsion systems. The solubilization of gamma-HCH also increased by 40.6-57.5% in microemulsion formed with Tween 80 and 43.0-65.8% in microemulsion formed with Triton X-100, compared with that in corresponding surfactant solutions only. Further studies revealed that both cosurfactant content and oil content could influence the solubilizing capacity of microemulsions system, and higher solubilizing capacity could be obtained when more cosurfactant or oil were emulsified in microemulsion system. Between the two, oil content is more influential than cosurfactant content. The present results affirm the effective role of microemulsions formed with Tween 80 and Triton X-100 in enhancing the solubilization of DDT and gamma-HCH which would facilitate remediation of soils contaminated with these compounds. PMID:21780695

  17. In Vitro Evaluation of Antimicrobial Efficacy of Extracts Obtained from Raw and Fermented Wild Macrofungus, Lenzites quercina

    PubMed Central

    Ogidi, Olusola Clement; Oyetayo, Victor Olusegun; Akinyele, Bamidele Juliet

    2015-01-01

    In recent time, there is a major concern about antibiotic resistance displayed by some pathogenic microorganisms and this had involved a continuous search for natural antimicrobial products. The phytochemistry as well as antimicrobial activity of extracts obtained from Lenzites quercina was investigated. The extracts and purified fractions were, respectively, tested against indicator organisms using agar well diffusion and disc diffusion methods. The quantity of phytochemicals found in the extracts of L. quercina ranged from 14.4 to 20.7 mg/g for alkaloids, 6.1 to 12.8 mg/g for steroids, 4.5 to 10.6 mg/g for saponins, 2.8 to 17.2 mg/g for terpenoids, and 0.41 to 17.1 mg/g for flavonoids. The gas chromatography mass spectrophotometry (GCMS) analysis of the extract reveals the presence of caprylic acid, stearic acid, tetradecanoic acid, methyl-11-octadecenoate, oleic acid, and 4-methyl-2-propyl-1-pentanol. Extracts of L. quercina and its purified fractions exhibited wider range of inhibition (4 mm to 26 mm) on Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 35218), Methicillin Resistant Staphylococcus aureus (MRSA), Salmonella typhi, Bacillus cereus, Enterococcus faecalis, Candida albicans, and Aspergillus niger. The antimicrobial effects of L. quercina extracts indicate that this wild macrofungus contains significant amount of pharmacological agents, which could be extracted to curb the menace of antibiotic resistances by pathogenic organisms. PMID:26604928

  18. Effect of Selected Volatiles on Two Stored Pests: The Fungus Fusarium verticillioides and the Maize Weevil Sithophilus zeamais.

    PubMed

    Zunino, María P; Herrera, Jimena M; Pizzolitto, Romina P; Rubinstein, Héctor R; Zygadlo, Julio A; Dambolena, José S

    2015-09-01

    New agronomic practices and technology enabled Argentina a larger production of cereal grains, reaching a harvest yield of 26.5 million metric tons of maize, of which, about 40% was exported. However, much of the maize production is lost annually by the attack of fungi and insects (2.6 million tons). In this study, the antifungal effect of selected volatiles on Fusarium verticillioides, its mycotoxin production, and the repellent and insecticidal activities against the weevill Sithophilus zeamais, an insect vector of F. verticillioides, were evaluated. The compounds tested were (2E)-2-hexenal, (2E)-2-nonenal, (2E,6Z)-2,6-nonadienal, 1-pentanol, 1-hexanol, 1-butanol, 3-methyl-1-butanol, pentanal, 2-decanone, and 3-decanone, which occur in the blend of volatile compounds emitted by various cereal grains. The most active antifungals were the aldehydes (2E)-2-nonenal, (2E)-2-hexenal, and (2E,6Z)-2,6-nonadienal (minimum inhibitory concentration values of <0.03, 0.06, and 0.06 mM, respectively). The occurrence of fumonisin B1 also was prevented because these compounds completely inhibited fungal growth. The best insecticidal fumigant activities against the maize weevil were shown by 2-decanone and 3-decanone (lethal concentration ≤ 54.6 μL/L (<0.28 mM)). Although, all tested compounds showed repellent activity against S. zeamais at a concentration of 4 μL/L, (2E,6Z)-2,6-nonadienal was the most active repellent compound. These results demonstrate the potential of (2E,6Z)-2,6-nonadienal to be used as a natural alternative to synthetic pesticides on F. verticillioides and S. zeamais. PMID:26257042

  19. Gas-Phase Reactivity of Protonated 2-, 3-, and 4-Dehydropyridine Radicals Toward Organic Reagents

    NASA Astrophysics Data System (ADS)

    Adeuya, Anthony; Price, Jason M.; Jankiewicz, Bartłomiej J.; Nash, John J.; Kenttämaa, Hilkka I.

    2009-11-01

    To explore the effects of the electronic nature of charged phenyl radicals on their reactivity, reactions of the three distonic isomers of n-dehydropyridinium cation (n = 2, 3, or 4) have been investigated in the gas phase by using Fourier-transform ion cyclotron resonance mass spectrometry. All three isomers react with cyclohexane, methanol, ethanol, and 1-pentanol exclusively via hydrogen atom abstraction and with allyl iodide mainly via iodine atom abstraction, with a reaction efficiency ordering of 2 > 3 > 4. The observed reactivity ordering correlates well with the calculated vertical electron affinities of the charged radicals (i.e., the higher the vertical electron affinity, the faster the reaction). Charged radicals 2 and 3 also react with tetrahydrofuran exclusively via hydrogen atom abstraction, but the reaction of 4 with tetrahydrofuran yields products arising from nonradical reactivity. The unusual reactivity of 4 is likely to result from the contribution of an ionized carbene-type resonance structure that facilitates nucleophilic addition to the most electrophilic carbon atom (C-4) in this charged radical. The influence of such a resonance structure on the reactivity of 2 is not obvious, and this may be due to stabilizing hydrogen-bonding interactions in the transition states for this molecule. Charged radicals 2 and 3 abstract a hydrogen atom from the substituent in both phenol and toluene, but 4 abstracts a hydrogen atom from the phenyl ring, a reaction that is unprecedented for phenyl radicals. Charged radical 4 reacts with tert-butyl isocyanide mainly by hydrogen cyanide (HCN) abstraction, whereas CN abstraction is the principal reaction for 2 and 3. The different reactivity observed for 4 (as compared to 2 and 3) is likely to result from different charge and spin distributions of the reaction intermediates for these charged radicals.

  20. Effect of the thermodynamic properties of W/O microemulsions on samarium oxide nanoparticle size.

    PubMed

    Zhu, Wenqing; Xu, Lei; Ma, Jin; Yang, Rui; Chen, Yashao

    2009-12-01

    In this work, we report the preparation of the Sm2O3 nanoparticle precursors (Sm(OH)3) via a simple W/O microemulsion process, in which microemulsions of cetyltrimethylammonium bromide (CTAB)/alkanol/1-octane/Sm(NO3)3 aqueous solution were added into sodium hydroxide (NaOH) aqueous solutions. The Sm2O3 nanoparticles were then prepared by calcining the precursors at 900 degrees C. Particularly, DeltaG(c-->i), which is the change in standard Gibbs free energy for transferring cosurfactant from the continuous phase to the microemulsion interface and can be used to estimate the thermodynamic properties of microemulsions, was determined using the dilution method. The effects of alkanol carbon chain length (1-pentanol, 1-hexanol, 1-heptanol and 1-octanol) and the reaction temperatures (298, 308, 318 and 328 K) on both DeltaG(c-->i) and Sm2O3 nanoparticle size have been investigated. Specifically, the Sm2O3 nanoparticle size, when calcined at 900 degrees C, was found to be mainly controlled by DeltaG(c-->i), and was thereby affected by the thermodynamic properties of microemulsions. The obtained products were characterized by DSC-TGA, XRD, TEM and UV-Vis. The results showed that DeltaG(c-->i) decreased with the increase in both the length of alkanol carbon chain and the reaction temperature, and the average size of Sm2O3 nanoparticles decreased as DeltaG(c-->i) decreased. The effect of microemulsion thermodynamic properties on Sm2O3 nanoparticle size reported here can provide some insights in controllable preparation of other rare earth oxide nanoparticles via the microemulsion route. PMID:19740477

  1. Exhalation of volatile organic compounds during hemorrhagic shock and reperfusion in rats: an exploratory trial.

    PubMed

    Hüppe, Tobias; Lorenz, Dominik; Maurer, Felix; Albrecht, Frederic W; Schnauber, Kristina; Wolf, Beate; Sessler, Daniel I; Volk, Thomas; Fink, Tobias; Kreuer, Sascha

    2016-03-01

    Ischemia and reperfusion alter metabolism. Multi-capillary column ion-mobility spectrometry (MCC-IMS) can identify volatile organic compounds (VOCs) in exhaled gas. We therefore used MCC-IMS to evaluate exhaled gas in a rat model of hemorrhagic shock with reperfusion. Adult male Sprague-Dawley rats (n  =  10 in control group, n  =  15 in intervention group) were anaesthetized and ventilated via tracheostomy for 14 h or until death. Hemorrhagic shock was maintained for 90 min by removing blood from the femoral artery to a target of MAP 35  ±  5 mmHg, and then retransfusing the blood over 60 min in 15 rats; 10 control rats were evaluated without shock and reperfusion. Exhaled gas was analyzed with MCC-IMS, VOCs were identified using the BS-MCC/IMS analytes database (Version 1209). VOC intensities were analyzed at the end of shock, end of reperfusion, and after 9 h. All normotensive animals survived the observation period, whereas mean survival time was 11.2 h in shock and reperfusion animals. 16 VOCs differed significantly for at least one of the three analysis periods. Peak intensities of butanone, 2-ethyl-1-hexanol, nonanal, and an unknown compound were higher in shocked than normotensive rats, and another unknown compound increased over the time. 1-butanol increased only during reperfusion. Acetone, butanal, 1.2-butandiol, isoprene, 3-methylbutanal, 3-pentanone, 2-propanol, and two unknown compounds were lower and decreased during shock and reperfusion. 1-pentanol and 1-propanol were significant greater in the hypotensive animals during shock, were comparable during reperfusion, and then decreased after resuscitation. VOCs differ during hemorrhagic shock, reperfusion, and after reperfusion. MCC-IMS of exhaled breath deserves additional study as a non-invasive approach for monitoring changes in metabolism during ischemia and reperfusion. PMID:26971584

  2. In Vitro Evaluation of Antimicrobial Efficacy of Extracts Obtained from Raw and Fermented Wild Macrofungus, Lenzites quercina.

    PubMed

    Ogidi, Olusola Clement; Oyetayo, Victor Olusegun; Akinyele, Bamidele Juliet

    2015-01-01

    In recent time, there is a major concern about antibiotic resistance displayed by some pathogenic microorganisms and this had involved a continuous search for natural antimicrobial products. The phytochemistry as well as antimicrobial activity of extracts obtained from Lenzites quercina was investigated. The extracts and purified fractions were, respectively, tested against indicator organisms using agar well diffusion and disc diffusion methods. The quantity of phytochemicals found in the extracts of L. quercina ranged from 14.4 to 20.7 mg/g for alkaloids, 6.1 to 12.8 mg/g for steroids, 4.5 to 10.6 mg/g for saponins, 2.8 to 17.2 mg/g for terpenoids, and 0.41 to 17.1 mg/g for flavonoids. The gas chromatography mass spectrophotometry (GCMS) analysis of the extract reveals the presence of caprylic acid, stearic acid, tetradecanoic acid, methyl-11-octadecenoate, oleic acid, and 4-methyl-2-propyl-1-pentanol. Extracts of L. quercina and its purified fractions exhibited wider range of inhibition (4 mm to 26 mm) on Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 35218), Methicillin Resistant Staphylococcus aureus (MRSA), Salmonella typhi, Bacillus cereus, Enterococcus faecalis, Candida albicans, and Aspergillus niger. The antimicrobial effects of L. quercina extracts indicate that this wild macrofungus contains significant amount of pharmacological agents, which could be extracted to curb the menace of antibiotic resistances by pathogenic organisms. PMID:26604928

  3. Determination of volatile compounds in wine by gas chromatography-flame ionization detection: comparison between the U.S. Environmental Protection Agency 3sigma approach and Hubaux-Vos calculation of detection limits using ordinary and bivariate least squares.

    PubMed

    Caruso, Rosario; Scordino, Monica; Traulo, Pasqualino; Gagliano, Giacomo

    2012-01-01

    A capillary GC-flame ionization detection (FID) method to determine volatile compounds (ethyl acetate, 1,1-diethoxyethane, methyl alcohol, 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-butanol, and 2-butanol) in wine was investigated in terms of calculation of detection limits and calibration method. The main objectives were: (1) calculation of regression coefficient parameters by ordinary least-squares (OLS) and bivariate least-squares (BLS) regression models, taking into account errors in both axes; (2) estimation of linear dynamic range (LDR) according to International Conference on Harmonization recommendations; (3) performance evaluation of a method by using three different internal standards (ISs) such as acetonitrile, acetone, and 1-pentanol; (4) evaluation of LODs according to the U.S. Environmental Protection Agency (EPA) 3sigma approach and the Hubaux-Vos (H-V) method; (5) application of H-V theory to a gas chromatographic analytical method and to a food matrix; and (6) accuracy assessment of the method relative to methyl alcohol content through a Unione Italiana Vini (UIV) interlaboratory proficiency test. Calibration curves calculated via BLS and OLS show similar slopes, while intercepts are closer to zero in the first case, independent of the chosen IS. The studied ISs show a substantially equivalent behavior, even though the IS closer to the analyte retention time seems to be more appropriate in terms of LDR and LOD. Results indicate an underestimation of LODs using the EPA 3sigma approach instead of the more realistic H-V method, both with OLS and BLS regression models. Methanol contents compared with UIV average values indicate recovery between 90 and 110%. PMID:22649934

  4. Analysis of thiabendazole, 4-tert-octylphenol and chlorpyrifos in waste and sewage water by direct injection – micellar liquid chromatography.

    PubMed

    Romero-Cano, Ricard; Kassuha, Diego; Peris-Vicente, Juan; Roca-Genovés, Pasqual; Carda-Broch, Samuel; Esteve-Romero, Josep

    2015-03-01

    A micellar liquid chromatographic method has been developed for the simultaneous quantification of the pesticides thiabendazole and chlorpyrifos, as well as an alkylphenol, which is included in pesticide formulations, i.e., 4-tert-octylphenol, in water. A sample was filtered and directly injected, avoiding large extraction steps using toxic solvents, thus expediting the experimental procedure. The contaminants were eluted without interferences in <17 min, using a mobile phase of 0.15 M sodium dodecyl sulfate – 6% 1-pentanol buffered at pH 3, running through a C18 column at 1 mL min(-1) under the isocratic mode. This optimal mobile phase was selected using a statistical approach, which considers the retention factor, efficiency and peak shape of the analytes measured in only a few mobile phases. The detection was carried out by measuring absorbance at 220 nm. The method was successfully validated in terms of specificity, calibration range (0.5-10 mg L(-1)), linearity (r(2) > 0.994), limit of detection and quantification (0.2-0.3; and 0.5-0.8 mg L(-1), respectively), intra- and interday accuracy (95.2-102.9%), precision (<8.3%), and ruggedness (<9.3%). The stability in storage conditions (at least 14 days) was studied. The method was safe, inexpensive, produced little pollutant and has a short analysis time, thus it is useful for the routine analysis of samples. Finally, the method was applied to analyse wastewater from the fruit-processing industry, wastewater treatment plants, and in sewage water belonging to the Castelló area (Spain). The results were similar to those obtained by an already reliable method. PMID:25604004

  5. Microfluidic processing of concentrated surfactant mixtures: online SAXS, microscopy and rheology.

    PubMed

    Martin, Hazel P; Brooks, Nicholas J; Seddon, John M; Luckham, Paul F; Terrill, Nick J; Kowalski, Adam J; Cabral, João T

    2016-02-14

    We investigate the effect of microfluidic flow on the microstructure and dynamics of a model surfactant mixture, combining synchrotron Small Angle X-ray Scattering (SAXS), microscopy and rheology. A system comprising a single-chain cationic surfactant, hexadecyl trimethyl ammonium chloride (C16TAC), a short-chain alcohol (1-pentanol) and water was selected for the study due to its flow responsiveness and industrial relevance. Model flow fields, including sequential contraction-expansion (extensional) and rotational flows, were investigated and the fluid response in terms of the lamellar d-spacing, orientation and birefringence was monitored in situ, as well as the recovery processes after cessation of flow. Extensional flows are found to result in considerable d-spacing increase (from approx 59 Å to 65 Å). However, under continuous flow, swelling decreases with increasing flow velocity, eventually approaching the equilibrium values at velocities ≃2 cm s(-1). Through individual constrictions we observe the alignment of lamellae along the flow velocity, accompanied by increasing birefringence, followed by an orientation flip whereby lamellae exit perpendicularly to the flow direction. The resulting microstructures are mapped quantitatively onto the flow field in 2D with 200 μm spatial resolution. Rotational flows alone do not result in appreciable changes in lamellar spacing and flow type and magnitude evidently impact the fluid microstructure under flow, as well as upon relaxation. The findings are correlated with rheological properties measured ex situ to provide a mechanistic understanding of the effect of flow imposed by tubular processing units in the phase behavior and performance of a model surfactant system with ubiquitous applications in personal care and coating industries. PMID:26739043

  6. Gas-phase reactivity of protonated 2-, 3-, and 4-dehydropyridine radicals toward organic reagents.

    PubMed

    Adeuya, Anthony; Price, Jason M; Jankiewicz, Bartłomiej J; Nash, John J; Kenttämaa, Hilkka I

    2009-12-10

    To explore the effects of the electronic nature of charged phenyl radicals on their reactivity, reactions of the three distonic isomers of n-dehydropyridinium cation (n = 2, 3, or 4) have been investigated in the gas phase by using Fourier-transform ion cyclotron resonance mass spectrometry. All three isomers react with cyclohexane, methanol, ethanol, and 1-pentanol exclusively via hydrogen atom abstraction and with allyl iodide mainly via iodine atom abstraction, with a reaction efficiency ordering of 2 > 3 > 4. The observed reactivity ordering correlates well with the calculated vertical electron affinities of the charged radicals (i.e., the higher the vertical electron affinity, the faster the reaction). Charged radicals 2 and 3 also react with tetrahydrofuran exclusively via hydrogen atom abstraction, but the reaction of 4 with tetrahydrofuran yields products arising from nonradical reactivity. The unusual reactivity of 4 is likely to result from the contribution of an ionized carbene-type resonance structure that facilitates nucleophilic addition to the most electrophilic carbon atom (C-4) in this charged radical. The influence of such a resonance structure on the reactivity of 2 is not obvious, and this may be due to stabilizing hydrogen-bonding interactions in the transition states for this molecule. Charged radicals 2 and 3 abstract a hydrogen atom from the substituent in both phenol and toluene, but 4 abstracts a hydrogen atom from the phenyl ring, a reaction that is unprecedented for phenyl radicals. Charged radical 4 reacts with tert-butyl isocyanide mainly by hydrogen cyanide (HCN) abstraction, whereas CN abstraction is the principal reaction for 2 and 3. The different reactivity observed for 4 (as compared to 2 and 3) is likely to result from different charge and spin distributions of the reaction intermediates for these charged radicals. PMID:19902945

  7. Contribution of Liver Alcohol Dehydrogenase to Metabolism of Alcohols in Rats

    PubMed Central

    Plapp, Bryce V.; Leidal, Kevin G.; Murch, Bruce P.; Green, David W.

    2015-01-01

    The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5–20 mmole/kg. Ethanol was eliminated most rapidly, at 7.9 mmole/kg•h. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5–10 mmole/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmole/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6 ± 1 mmole/kg•h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD+ for the conversion to ketones whereas primary alcohols require two equivalents of NAD+ for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD+ is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189

  8. An examination of the H/D isotope substitution effect on selectivity and activity in the cavitating ultrasound hydrogenation of aqueous 3-buten-2-ol and 1,4-pentadien-3-ol on Pd-black

    SciTech Connect

    Boyles, Kelly R.; Chajkowski, Sarah M.; Disselkamp, Robert S.; Peden, Charles HF

    2006-05-24

    An H/D isotope effect study of the (H2 versus D2) hydrogenation of the aqueous substrates 3-buten-2-ol (3B2OL) and 1,4-pentadien-3-ol (14PD3OL) was performed using Pd-black catalyst. Either H2O or D2O solvents were employed (for alcohol H/D isotope substitution). Two experimental processing conditions of cavitating ultrasound (CUS) and stirred/silent (SS) methods were used. Products formed include 2-butanol and 2-butanone for the former, and 3-pentanol and 3-pentanone for the latter. The observed selectivity and pseudo-first order reaction rate coefficients (e.g., activity) to these products enabled a mechanistic interpretation of the various reaction conditions to be proposed. Experiments utilized a 50 mL batch reactor maintained at 298 K, employed 5.4 atm of H2 or D2 gas, while seven aliquots were collected during the course of the reaction. We have utilized 1-propanol as an inert dopant in all experiments to enable the rapid onset of cavitation in the CUS systems as described earlier [R.S. Disselkamp et al., J. Catal., 227, 552 (2004)]. The following conclusions were noted. First, the activity of the CUS compared to SS processing were ~100-fold larger. Second, variable catalyst loading experiments for stirred/silent D2 hydrogenation processing indicated that mass transfer of hydrogen gas to the Pd-surface played a role such that higher catalyst loading reduced surface D-atom concentrations and reduced saturated alcohol formation (e.g., via reduced H-addition to surface alkyl radicals). Third, for CUS processing the ketone selectivities for experiments employing water compared to D2O indicated that 3B2OL were twice as large, whereas for 14PD3OL they were comparable. This suggests, somewhat surprisingly, that for 3B2OL enol tautomerization to ketone is a slow, and possibly rate-controlling, process. Finally, again for CUS processing, the similarity in ketone selectivities (all ~17%) for H2 compared to D2 hydrogenation for both 3B2OL and 14PD3OL suggest that both H

  9. Organic compound composition in soil and sediments collected in Jackson, Mississippi.

    PubMed

    Gołębiowski, Marek; Stepnowski, Piotr; Hemmingway, Tometrick; Leszczyńska, Danuta

    2016-06-01

    The aim of our study was to identify organic pollutants found in soil and sediment samples collected within the Jackson, MS metropolitan area. The chemical characterization of the organic compound fractions in soil and sediment samples was carried out by separating the organic fraction using column chromatography (CC) and quantitatively analyzing the polycyclic aromatic hydrocarbons (PAHs), n-alkanes and other organic compounds using gas chromatography-electron impact mass spectrometry (GC-MS). Fifty-six compounds were identified and quantified in the soil samples and 33 compounds were identified and quantified in the sediment samples. The PAHs, n-alkanes and other organic compound profiles in the soil and sediment samples were compared. The percentage contents of the organic compounds in the soil samples were very diverse (from traces to 12.44 ± 1.47%). The compounds present in the highest concentrations were n-alkanes: n-C31 (12.44 ± 1.47%), n-C29 (11.64 ± 1.21%), and n-C33 (8.95 ± 1.08%). The components occurring in smaller quantities (from 1% to 5%) were 2 PAHs (fluoranthene 1.28 ± 0.25%, pyrene 1.16 ± 0.20%), 10 n-alkanes from n-C21 (1.25 ± 0.29%) to n-C32 (2.67 ± 0.52%) and 11 other compounds (e.g., 2-pentanol, 4-methyl (3.33 ± 0.44%), benzyl butyl phthalate (4.25 ± 0.59%), benzenedicarboxylic acid (1.14 ± 0.08%), ethane, 1,1-diethoxy (3.15 ± 0.41) and hexadecanoic acid (2.52 ± 0.34). The soil samples also contained 30 compounds present in concentrations <1% (e.g., anthracene (0.13 ± 0.04%), n-C20 (0.84 ± 0.21%) and acetic acid (0.12 ± 0.04%). The compounds present in the highest concentrations in the sediment samples were PAHs: pyrene (7.73 ± 1.15%) and fluoranthene (6.23 ± 1.07%) and n-alkanes: n-C31 (6.74 ± 1.21%), n-C29 (6.65 ± 0.98%) and n-C27 (6.13 ± 1.09%). The remaining organic compounds were present in smaller quantities (< 5%). PMID:26943144

  10. Catalytic characterization of lithium aluminum oxides: Including a study of both the cation replacement chemistry and the structure of the [alpha]LiAlO[sub 2]/[open quotes]HAlO[sub 2][close quotes] system

    SciTech Connect

    Tomczak, D.C.

    1993-01-01

    Cation replacement is a low temperature synthetic technique used to replace most of the lithium cations in [alpha]LiAlO[sub 2] with protons without significantly modifying the structure of the reactant. Lauric acid worked well as a proton source because it was capable of 90% replacement without significant dissolution of [alpha]LiAlO[sub 2]. High pressure CO[sub 2]/H[sub 2]O treatment of the cation replaced product resulted in the decomposition of the reactant to form boehmite and Li[sub 2]CO[sub 3]. The XRD characterization of a series of partially replaced samples from the [alpha]LiAlO[sub 2]/HAlO[sub 2] system was used to develop an understanding of the cation replacement mechanism. A two phase mechanism is proposed, which consists of particles with an outer shell of lithiated HAlO[sub 2] and an inner core of [alpha]LiAlO[sub 2] (for 0.0 < x < 0.90). A model for the structure of HAlO[sub 2] was developed to describe the location of the protons and the lithium cations. The 3,3-dimethyl-1-isomerization reaction did not detect any intrinsic acidity on HAlO[sub 2] and detected only small amounts on calcined HAlO[sub 2] at 350[degrees]C. Lithium free [gamma]-alumina was extremely active for 3,3-dimethyl-1-butene isomerization demonstrating that the small concentration of lithium in both HAlO[sub 2] and calcined HAlO[sub 2] is sufficient to neutralize strong acid sites. The conversion of isopropyl alcohol produces propylene on acid-base sites and acetone on basic sites. [alpha]LiAlO[sub 2], [gamma]LiAlO[sub 2], and calcined HAlO[sub 2], produced varying amounts of propylene and acetone. [alpha]LiAlO[sub 2] and calcined HAlO[sub 2] produced a C6 diene, which indicates the presence of basic sites stronger than those needed for acetone formation. [alpha]LiAlO[sub 2] was the only sample that produced 4-methyl-2-pentanone and 4-methyl-2-pentanol.

  11. Involvement of reversible binding to alpha 2u-globulin in 1,4-dichlorobenzene-induced nephrotoxicity.

    PubMed

    Charbonneau, M; Strasser, J; Lock, E A; Turner, M J; Swenberg, J A

    1989-06-01

    Similarly to unleaded gasoline, 1,4-dichlorobenzene (1,4-DCB) administered for 2 years caused a dose-related increase in the incidence of renal tumors in male but not in female rats or in either sex of mice. Unleaded gasoline and 2,2,4-trimethylpentane (TMP), a component of unleaded gasoline, increased protein droplet formation and cell proliferation in male but not in female rat kidneys. These protein droplets contained, alpha 2u-globulin, a male rat-specific low-molecular-weight protein and 2,4,4-trimethyl-2-pentanol, a metabolite of TMP that was reversibly bound to this protein. Studies were undertaken to determine if 1,4-DCB produced similar effects; 1,2-DCB was used for comparison since it did not produce renal carcinogenesis in male rats. Gel filtration chromatography of a 116,000g supernatant prepared from kidneys of 1,4-[14C]DCB-treated rats showed that radiolabel coeluted with alpha 2u-globulin as one sharp peak as opposed to a multipeak pattern observed for 1,2-[14C]DCB; the maximal quantity of radiolabel for 1,4-DCB was twice that for 1,2-DCB. Equilibrium dialysis of kidney cytosol in the presence or absence of sodium dodecyl sulfate demonstrated that the radiolabel was reversibly bound to alpha 2u-globulin; the amount for 1,4-[14C]DCB-treated rats was almost twice as much as that for 1,2-[14C]DCB-treated rats. 1,2-DCB was also shown to be covalently bound to renal alpha 2u-globulin, and covalently bound to liver and plasma high-molecular-weight proteins. 1,4-DCB and, to a minor extent, 2,5-dichlorophenol, the major metabolite of 1,4-DCB, were reversibly bound to renal alpha 2u-globulin from 1,4-DCB-treated rats. 1,4-DCB increased protein droplet formation in male but not in female rat kidneys, whereas equimolar doses of 1,2-DCB showed no effect in either sex. Renal cell proliferation, measured by [3H]thymidine incorporation into renal DNA, was increased after 1,4-DCB but not after 1,2-DCB treatment. Nephrotoxicity and biochemical alterations induced by

  12. Aliphatic β-Nitroalcohols for Therapeutic Corneoscleral Cross-linking: Chemical Mechanisms and Higher Order Nitroalcohols

    PubMed Central

    Solomon, Marissa R.; Wen, Quan; Turro, Nicholas J.; Trokel, Stephen L.

    2010-01-01

    Purpose. The recent tissue cross-linking studies indicate that aliphatic β-nitroalcohols (BNAs) may be useful as pharmacologic corneoscleral cross-linking agents. The present study was performed to identify the specific chemistry involved under physiologic conditions, with the intent of identifying more effective agents. Methods. The mechanism of chemical cross-linking at pH 7.4 and 37°C was studied using three techniques. The colorimetric Griess assay was used to follow the release of nitrite from three mono-nitroalcohols (2-nitroethanol [2ne], 2-nitro-1-propanol [2nprop]), and 3-nitro-2-pentanol [3n2pent]). Second, the evolution of 2nprop in 0.2 M NaH2PO4/Na2HPO4/D2O was studied using 1H-NMR. Third, thermal shrinkage temperature analysis (Ts), a measure of tissue cross-linking, was used to support information from 1the H-NMR studies. Results. A time-dependent release of nitrite was observed for all three mono-nitroalcohols studied. The maximum levels were comparable using either 2ne or 2nprop (∼30%). However, much less (∼10%) was observed from 3n2pent. Using 1H-NMR, 2nprop evolved into a unique splitting pattern. No match was observed with reference spectra from three possible products of denitration. In contrast, 2-methyl-2-nitro-1,3-propanediol (MNPD), a nitro-diol, was identified, implying the formation of formaldehyde from a retro-nitroaldol (i.e., reverse Henry) reaction. In support of this mechanism, Ts shifts induced by the nitro-triol 2-hydroxymethyl-2-nitro-1,3-propanediol (HNPD) were superior to the nitro-diol MNPD which were superior to the mono nitroalcohol 2nprop. Conclusions. BNAs function as both formaldehyde and nitrite donors under physiologic conditions to cross-link collagenous tissue. Higher order BNAs are more effective than mono nitroalcohols, raising the possibility of using these agents for therapeutic corneoscleral cross-linking. PMID:19797229

  13. 2,2,4-Trimethylpentane-induced nephrotoxicity. II. The reversible binding of a TMP metabolite to a renal protein fraction containing alpha 2u-globulin.

    PubMed

    Lock, E A; Charbonneau, M; Strasser, J; Swenberg, J A; Bus, J S

    1987-11-01

    Trimethylpentane (TMP) produces nephrotoxicity in male but not in female rats. The toxicity is characterized by an increase in protein droplets in proximal convoluted tubular cells and an increase in the renal concentration of the male-rat-specific protein alpha 2u-globulin. Subcellular fractionation of the kidneys from male rats 24 hr after [3H]TMP administration showed that about 60% of the radiolabeled material was localized in the 116,000g supernatant. Column chromatography of this supernatant resolved the radioactivity into two components; one, which contained about 26% of the radiolabel, coeluted with alpha 2u-globulin and cross-reacted with an antibody specific for alpha 2u-globulin. The remaining component eluted in the low-molecular-weight range (less than 1000 Da) and was assumed to be TMP metabolites. Radiolabel from [3H]TMP in male rat urine also resolved into two components with about 0.1% of the radiolabel in urine coeluting with the alpha 2u-globulin-containing fraction. Radiolabel from TMP in male rat liver 116,000g supernatant and plasma and in female rat kidney 116,000g supernatant eluted as a single component in the low-molecular-weight range. Dialysis (1000-Da cutoff) of male kidney 116,000g supernatant led to a loss of the low-molecular-weight components, but nondialyzable radiolabel (about 20%) still coeluted with the alpha 2u-globulin after gel chromatography. Dialysis against 0.1% sodium dodecyl sulfate led to a loss of both the low- and high-molecular-weight radioactive material. These results suggested that the high-molecular-weight radioactive material was formed by the reversible binding of a radioactive component of TMP to a male-rat-specific protein. Gas chromatography-mass spectrometry of an ethyl acetate extract of the alpha 2u-globulin-containing fractions of TMP-treated male rat kidney 116,000g supernatant identified 2,4,4-trimethyl-2-pentanol as the only bound metabolite to alpha 2u-globulin. These studies provide the first

  14. The effect of cavitating ultrasound on the aqueous phase hydrogenation of cis-2-buten-1-ol and cis-2-penten-1-ol on Pd-black

    SciTech Connect

    Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.; White, James F.; Peden, Charles HF.

    2005-07-15

    We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [R.S. Disselkamp, Ya-Huei Chin, C.H.F. Peden, J. Catal. 227 (2004) 552]. The motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content.We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2 C3 double bond slowing isomerization. Since seed oils are C18 multiple cis-olefins and have a moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.

  15. The Effect of Cavitating Ultrasound on the Aqueous Phase Hydrogenation of Cis-2-buten-1-ol and Cis-2-penten-1-ol on Pd-black

    SciTech Connect

    Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.; White, James F.; Peden, Charles HF.

    2005-07-15

    We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [Disselkamp et al., J. Catal., 227 (2004) 552]. The motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content. We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2=C3 double bond slowing isomerization. Since seed oils are C18 multiple cis olefins and have an moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.

  16. An efficient and general route to reduced polypropionates via Zr-catalyzed asymmetric CC bond formation.

    PubMed

    Negishi, Ei-Ichi; Tan, Ze; Liang, Bo; Novak, Tibor

    2004-04-20

    An efficient and general method for the synthesis of reduced polypropionates has been developed through the application of asymmetric carboalumination of alkenes catalyzed by dichlorobis(1-neomenthylindenyl)zirconium [(NMI)(2)ZrCl(2)]. In this investigation, attention has been focused on those reduced polypropionates that are alpha-monoheterofunctional and either omega-ethyl or omega-n-propyl. The reaction of 3-buten-1-ol with triethylaluminum (Et(3)Al) or tripropylaluminum ((n)Pr(3)Al) in the presence of (NMI)(2)ZrCl(2) and isobutylaluminoxane gave, after protonolysis, (R)-3-methyl-1-pentanol as well as (R)- and (S)-3-methyl-1-hexanols in 88-92% yield in 90-92% enantiomeric excess in one step. These 3-monomethyl-1-alkanols were then converted to two stereoisomers each of 2,4-dimethyl-1-hexanols and 2,4-dimethyl-1-heptanols via methylalumination catalyzed by (NMI)(2)ZrCl(2) and methylaluminoxane followed by oxidation with O(2). The four-step (or three-isolation-step) protocol provided syn-2,4-dimethyl-1-alkanols of >/=98% stereoisomeric purity in approximately 50% overall yields, whereas (2S,4R)-2,4-dimethyl-1-hexanol of comparable purity was obtained in 40% overall yield. Commercial availability of (S)-2-methyl-1-butanol as a relatively inexpensive material suggested its use in the synthesis of (2S,4S)- and (2R,4S)-2,4-dimethyl-1-hexanols via a three-step protocol consisting of (i) iodination, (ii) zincation followed by Pd-catalyzed vinylation, and (iii) Zr-catalyzed methylalumination followed by oxidation with O(2). This three-step protocol is iterative and applicable to the synthesis of reduced polypropionates containing three or more branching methyl groups, rendering this method for the synthesis of reduced polypropionates generally applicable. Its synthetic utility has been demonstrated by preparing the side chain of zaragozic acid A and the C11-C20 fragment of antibiotics TMC-151 A-F. PMID:15073327

  17. Milk volatile organic compounds and fatty acid profile in cows fed timothy as hay, pasture, or silage.

    PubMed

    Villeneuve, M-P; Lebeuf, Y; Gervais, R; Tremblay, G F; Vuillemard, J C; Fortin, J; Chouinard, P Y

    2013-01-01

    Nutrient composition and organoleptic properties of milk can be influenced by cow diets. The objective of this study was to evaluate the forage type effects on volatile organic compounds, fatty acid (FA) profile, and organoleptic properties of milk. Timothy grass was fed as hay, pasture, or silage during a period of 27 d to a group of 21 cows in a complete block design based on days in milk. Each cow also received 7.2 kg/d of a concentrate mix to meet their nutrient requirements. Forage dry matter intake averaged 13.9 kg/d and was not different among treatments. Milk yield was higher for cows fed pasture, intermediate for cows fed silage, and lowest for cows fed hay. However, milk fat content was higher for cows fed hay and silage, compared with cows fed pasture. As a result, fat-corrected milk and fat yield were not different among treatments. Increasing the supply of dietary cis-9,cis-12 18:2 (linoleic acid) and cis-9,cis-12,cis-15 18:3 (α-linolenic acid) when feeding pasture enhanced the concentration of these 2 essential FA in milk fat compared with feeding hay or silage. Moreover, the ratio of 16:0 (palmitic acid) to cis-9 18:1 (oleic acid), which is closely related to the melting properties of milk fat, was lower in milk from cows on pasture than in milk from cows fed hay or silage. Cows fed hay produced milk with higher levels of several free FA and γ-lactones, but less pentanal and 1-pentanol. More dimethyl sulfone and toluene were found in milk of cows on pasture. Cows fed silage produced milk with higher levels of acetone, 2-butanone, and α-pinene. Results from a sensory evaluation showed that panelists could not detect a difference in flavor between milk from cows fed hay compared with silage. However, a significant number of assessors perceived a difference between milk from cows fed hay compared with milk from cows fed pasture. In a sensory ranking test, the percentage of assessors ranking for the intensity of total (raw milk, fresh milk, and farm

  18. An efficient and general route to reduced polypropionates via Zr-catalyzed asymmetric C—C bond formation

    PubMed Central

    Negishi, Ei-ichi; Tan, Ze; Liang, Bo; Novak, Tibor

    2004-01-01

    An efficient and general method for the synthesis of reduced polypropionates has been developed through the application of asymmetric carboalumination of alkenes catalyzed by dichlorobis(1-neomenthylindenyl)zirconium [(NMI)2ZrCl2]. In this investigation, attention has been focused on those reduced polypropionates that are α-monoheterofunctional and either ω-ethyl or ω-n-propyl. The reaction of 3-buten-1-ol with triethylaluminum (Et3Al) or tripropylaluminum (nPr3Al) in the presence of (NMI)2ZrCl2 and isobutylaluminoxane gave, after protonolysis, (R)-3-methyl-1-pentanol as well as (R)- and (S)-3-methyl-1-hexanols in 88–92% yield in 90–92% enantiomeric excess in one step. These 3-monomethyl-1-alkanols were then converted to two stereoisomers each of 2,4-dimethyl-1-hexanols and 2,4-dimethyl-1-heptanols via methylalumination catalyzed by (NMI)2ZrCl2 and methylaluminoxane followed by oxidation with O2. The four-step (or three-isolation-step) protocol provided syn-2,4-dimethyl-1-alkanols of ≥98% stereoisomeric purity in ≈50% overall yields, whereas (2S,4R)-2,4-dimethyl-1-hexanol of comparable purity was obtained in 40% overall yield. Commercial availability of (S)-2-methyl-1-butanol as a relatively inexpensive material suggested its use in the synthesis of (2S,4S)- and (2R,4S)-2,4-dimethyl-1-hexanols via a three-step protocol consisting of (i) iodination, (ii) zincation followed by Pd-catalyzed vinylation, and (iii) Zr-catalyzed methylalumination followed by oxidation with O2. This three-step protocol is iterative and applicable to the synthesis of reduced polypropionates containing three or more branching methyl groups, rendering this method for the synthesis of reduced polypropionates generally applicable. Its synthetic utility has been demonstrated by preparing the side chain of zaragozic acid A and the C11–C20 fragment of antibiotics TMC-151 A–F. PMID:15073327

  19. Experimental study of the effect of test-well arrangement for partitioning interwell tracer test on the estimation of NAPL saturation

    NASA Astrophysics Data System (ADS)

    Kim, B.; Kim, Y.; Yeo, I.; Yongcheol Kim, In Wook Yeo

    2011-12-01

    Partitioning interwell tracer test (PITT) is a method to quantify and qualify a contaminated site with NAPLs through a degree of retardation of partitioning tracers compared to a conservative one. Although PITT is known to be a more effective method to measure the saturation of spatially-distributed NAPL contaminant than the point investigation method, the saturation estimation from PITT is reported to be underestimated due to various factors including heterogeneity of the media, adsorption, source zone NAPL architecture, and long tailing in breakthrough curves of partitioning tracers. Analytical description of PITT assumes that the injection-pumping well pair is on the line of ambient groundwater flow direction, but the test-well pair could easily be off the line in the field site, which could be another erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair to ambient groundwater flow direction based on the result from PITT. The experiments were conducted in a small-scale 3D sandbox with dimensions of 0.5 m × 0.4 m × 0.15 m (LWH) of stainless steel. The surface is covered and sealed with a plexiglass plate to make the physical model a confined aquifer. Eight full-screened wells of Teflon material were installed along the perimeter of a 50 mm circle with 45 degree intervals in the middle of the physical model. Both ends of the sand box are connected to constant head reservoirs. The physical model was wet-packed with sieved and washed sand. Trichloroethylene (TCE) and bromide were used as the contaminant and the conservative tracer, respectively. Hexanol, 2,4-dimethyl-3-pentanol and 6-methyl-2-heptanol were used as partitioning tracers. Before the injection of TCE, a PITT was conducted to measure adsorption coefficient of partitioning tracers to the sand material. TCE of 4.5 mL, dyed with Sudan IV, was injected into the inner part of the circle of the wells. PITTs using the test-well pair

  20. Methanomassiliicoccus luminyensis gen. nov., sp. nov., a methanogenic archaeon isolated from human faeces.

    PubMed

    Dridi, Bédis; Fardeau, Marie-Laure; Ollivier, Bernard; Raoult, Didier; Drancourt, Michel

    2012-08-01

    During attempts to obtain novel, human-associated species of the domain Archaea, a coccoid micro-organism, designated strain B10(T), was isolated in pure culture from a sample of human faeces collected in Marseille, France. On the basis of its phenotypic characteristics and 16S rRNA and mcrA gene sequences, the novel strain was classified as a methanogenic archaeon. Cells of the strain were non-motile, Gram-staining-positive cocci that were approximately 850 nm in diameter and showed autofluorescence at 420 nm. Cells were lysed by 0.1% (w/v) SDS. With hydrogen as the electron donor, strain B10(T) produced methane by reducing methanol. The novel strain was unable to produce methane when hydrogen or methanol was the sole energy source. In an atmosphere containing CO(2), strain B10(T) could not produce methane from formate, acetate, trimethylamine, 2-butanol, 2-propanol, cyclopentanol, 2-pentanol, ethanol, 1-propanol or 2,3-butanediol. Strain B10(T) grew optimally with 0.5-1.0% (w/v) NaCl, at pH 7.6 and at 37 °C. It required tungstate-selenite for growth. The complete genome of the novel strain was sequenced; the size of the genome was estimated to be 2.05 Mb and the genomic DNA G+C content was 59.93 mol%. In phylogenetic analyses based on 16S rRNA gene sequences, the highest sequence similarities (98.0-98.7%) were seen between strain B10(T) and several uncultured, methanogenic Archaea that had been collected from the digestive tracts of a cockroach, a chicken and mammals. In the same analysis, the non-methanogenic 'Candidatus Aciduliprofundum boonei' DSM 19572 was identified as the cultured micro-organism that was most closely related to strain B10(T) (83.0% 16S rRNA gene sequence similarity). Each of the three treeing algorithms used in the analysis of 16S rRNA gene sequences indicated that strain B10(T) belongs to a novel order that is distinct from the Thermoplasmatales. The novel strain also appeared to be distinct from Methanosphaera stadtmanae DSM 3091(T) (72

  1. A Unique Equation to Estimate Flash Points of Selected Pure Liquids Application to the Correction of Probably Erroneous Flash Point Values

    NASA Astrophysics Data System (ADS)

    Catoire, Laurent; Naudet, Valérie

    2004-12-01

    several flash points have been reported erroneously, whatever the reason, in one or several reference compilations. In the following lists, the currently accepted flash points for bold compounds err, or probably err, on the hazardous side by at least 10 °C and for the nonbolded compounds, the currently accepted flash points err, or probably err, on the nonhazardous side by at least 10 °C: bicyclohexyl, sec-butylamine, tert-butylamine, 2-cyclohexen-1-one, ethanethiol, 1,3-cyclohexadiene, 1,4-pentadiene, methyl formate, acetonitrile, cinnamaldehyde, 1-pentanol, diethylene glycol, diethyl fumarate, diethyl phthalate, trimethylamine, dimethylamine, 1,6-hexanediol, propylamine, methanethiol, ethylamine, bromoethane, 1-bromopropane, tert-butylbenzene, 1-chloro-2-methylpropane, diacetone alcohol, diethanolamine, 2-ethylbutanal, and formic acid. For some other compounds, no other data than the currently accepted flash points are available. Therefore, it cannot be assessed that these flash point data are erroneous but it can be stated that they are probably erroneous. At least, they need experimental re-examination. They are probably erroneous by at least 15 °C: 1,3-cyclopentadiene, di-tert-butyl sulfide, dimethyl ether, dipropyl ether, 4-heptanone, bis(2-chloroethyl)ether, 1-decanol, 1-phenyl-1-butanone, furan, ethylcyclopentane, 1-heptanethiol, 2,5-hexanediol, 3-hexanone, hexanoic acid methyl ester, 4-methyl-1,3-pentadiene, propanoyl chloride, tetramethylsilane, thiacyclopentane, 1-chloro-2-methyl-1-propene, trans-1,3-pentadiene, 2,3-dimethylheptane, triethylenetetramine, methylal, N-ethylisopropylamine, 3-methyl-2-pentene, and 2,3-dimethyl-1-butene.

  2. Decontamination of Tritiated-Water Using Super-hydrophobic Pt-Catalyst Synthesized with Water-in-Supercritical CO{sub 2}

    SciTech Connect

    Youichi Enokida; Kayo Sawada |; Ryosuke Shimizu; Ichiro Yamamoto

    2008-01-15

    was very small to detect, and this approach turns to be not successful. As the second approach, we utilize CO{sub 2} soluble Pt precursor, CODMe{sub 2}Pt purchased from Sigma-Aldrich Co. and H{sub 2} gas as reducing agent, which could be completely mixed with SC-CO{sub 2}. This system was well-known for Pt particle formation by auto-catalytic growth. The second approach was aiming at increasing Pt amount deposited in the gauze. This approach was successful in increasing Pt amount, but the Pt particle size also increased to be more than 50 nm, which was not suitable for catalyst. Finally, we synthesized the catalyst by the following procedure: firstly, a reducing agent of NaBH{sub 4} was deposited on the nano-textured hydrophobic layer on the gauze. This step was realized by forming reversed micelles of aqueous NaBH{sub 4} solution using a surfactant AOT and a co-surfactant 2,2,3,3,4,4,5,5,-octafluoro-1-pentanol (F-pentanol) in SC-CO{sub 2}. This system of surfactant combination of AOT and F-pentanol has been found to work successfully in recent studies. In the second step, the gauze was contacted with CODMe{sub 2}Pt dissolved in SC-CO{sub 2} to synthesize seeds of Pt particles for the auto-catalytic reaction proceeding by CODMe{sub 2}Pt with hydrogen. The seeds were formed by the reaction between deposited NaBH{sub 4} and CODMe{sub 2}Pt in SC-CO{sub 2}. The physical characterization of this catalyst was performed by SEM-EDS. By this procedure, the Pt hydrophobic catalyst where Pt nanoparticle of 10 nm in diameter was locally deposited in the nano-textured layer was successfully prepared. Hydrophobicity after the chemical Pt deposition was tested by measurement of water absorbed on the gauze and the catalyst performance was evaluated by {sup 1}H{sup 2}H formation through the scrambling reaction from {sup 1}H{sub 2} and {sup 2}H{sub 2} and the reaction was successfully observed. We demonstrated a new hydrophobic catalyst preparation using SC-CO{sub 2} effectively. We