A narrow pH range supports butanol, hexanol, and octanol production from syngas in a continuous co-culture of Clostridium ljungdahlii and Clostridium kluyveri with in-line product extraction

Directory of Open Access Journals (Sweden)

Hanno Richter

2016-11-01

Full Text Available Carboxydotrophic bacteria (CTB have received attention due to their ability to synthesize commodity chemicals from producer gas and synthesis gas (syngas. CTB have an important advantage of a high product selectivity compared to chemical catalysts. However, the product spectrum of wild-type CTB is narrow. Our objective was to investigate whether a strategy of combining two wild-type bacterial strains into a single, continuously fed bioprocessing step would be promising to broaden the product spectrum. Here, we have operated a syngas-fermentation process with Clostridium ljungdahlii and Clostridium kluyveri with in-line product extraction through gas stripping and product condensing within the syngas recirculation line. The main products from C. ljungdahlii fermentation at a pH of 6.0 were ethanol and acetate at net volumetric production rates of 65.5 and 431 mmol C•L-1•d-1, respectively. An estimated 2/3 of total ethanol produced was utilized by C. kluyveri to chain elongate with the reverse β-oxidation pathway, resulting in n-butyrate and n-caproate at net rates of 129 and 70 mmol C•L-1•d-1, respectively. C. ljungdahlii likely reduced the produced carboxylates to their corresponding alcohols with the reductive power from syngas. This resulted in the longer-chain alcohols n-butanol, n-hexanol, and n-octanol at net volumetric production rates of 39.2, 31.7, and 0.045 mmol C•L-1•d-1, respectively. The continuous production of the longer-chain alcohols occurred only within a narrow pH spectrum of 5.7-6.4 due to the pH discrepancy between the two strains. Regardless whether other wild-type strains could overcome this pH discrepancy, the specificity (mol carbon in product per mol carbon in all other liquid products for each longer-chain alcohol may never be high in a single bioprocessing step. This, because two bioprocesses compete for intermediates (i.e., carboxylates: 1 chain elongation; and 2 biological reduction. This innate

A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer

Directory of Open Access Journals (Sweden)

Damion K. Corrigan

2018-06-01

Full Text Available For analytical applications involving label-free biosensors and multiple measurements, i.e., across an electrode array, it is essential to develop complete sensor systems capable of functionalization and of producing highly consistent responses. To achieve this, a multi-microelectrode device bearing twenty-four equivalent 50 µm diameter Pt disc microelectrodes was designed in an integrated 3-electrode system configuration and then fabricated. Cyclic voltammetry and electrochemical impedance spectroscopy were used for initial electrochemical characterization of the individual working electrodes. These confirmed the expected consistency of performance with a high degree of measurement reproducibility for each microelectrode across the array. With the aim of assessing the potential for production of an enhanced multi-electrode sensor for biomedical use, the working electrodes were then functionalized with 6-mercapto-1-hexanol (MCH. This is a well-known and commonly employed surface modification process, which involves the same principles of thiol attachment chemistry and self-assembled monolayer (SAM formation commonly employed in the functionalization of electrodes and the formation of biosensors. Following this SAM formation, the reproducibility of the observed electrochemical signal between electrodes was seen to decrease markedly, compromising the ability to achieve consistent analytical measurements from the sensor array following this relatively simple and well-established surface modification. To successfully and consistently functionalize the sensors, it was necessary to dilute the constituent molecules by a factor of ten thousand to support adequate SAM formation on microelectrodes. The use of this multi-electrode device therefore demonstrates in a high throughput manner irreproducibility in the SAM formation process at the higher concentration, even though these electrodes are apparently functionalized simultaneously in the same film

Densities, speeds of sound and viscosities of binary mixtures of tetrahydrofuran with 1-hexanol, 1-octanol and 1-decanol at T = (298.15 to 313.15) K

International Nuclear Information System (INIS)

Dubey, Gyan Prakash; Kumar, Rajiv

2014-01-01

Highlights: • Thermodynamic study for the binary liquid mixtures has been made. has been made. • Excess molar volumes, deviations of speed of sound and excess molar isentropic compressibilities were determined. • Discussion has been carried out on the basis of types of interactions between the liquid molecules based on derived properties. -- Abstract: Density ρ, and speed of sound u, have been measured for the binary mixtures of tetrahydrofuran (C 4 H 8 O) with 1-hexanol, (C 6 H 14 O), 1-octanol, (C 8 H 18 O) and 1-decanol, (C 10 H 22 O) over the entire composition range at T = (298.15, 303.15, 308.15 and 313.15) K and at atmospheric pressure while viscosity, η was measured at T = (298.15, 303.15, 308.15) K and at atmospheric pressure. The experimental density and speed of sound values were used to calculate the excess molar volumes VmE, deviations in speed of sound u D and excess molar isentropic compressibility K S,m E , while the viscosity data were used to compute excess Gibbs energy of activation of viscous flow, ΔG *E at 298.15, 303.15 and 308.15 K. The values of VmE, u D and K S,m E were fitted to the Redlich–Kister polynomial equation and the viscosity data have been correlated by using the equations of Grunberg–Nissan, Tamura–Kurata, Hind et al., Heric–Brewer (three parameter) and McAllister (four body interactions) and have been used to discuss the presence of significant interactions between cyclic ether and alcohols

Competition between a lamellar and a microemulsion phase in an ionic surfactant system

NARCIS (Netherlands)

Kegel, W.K.; Lekkerkerker, H.N.W.

1993-01-01

An experimental study of a microemulsion system consisting of equal volumes of brine (water plus salt) and oil (cyclohexane), sodium dodecyl sulfate (SDS) as surfactant, and a mixture of hexanol and pentanol as cosurfactant is presented. Increasing the hexanol fraction in the cosurfactant mixture

Aroma changes in fresh bell peppers (Capsicum annuum) after hot-air drying.

NARCIS (Netherlands)

Luning, P.A.; Yuksel, D.; Vuurst de Vries, van R.; Roozen, J.P.

1995-01-01

The aroma of fresh and hot-air dried bell peppers (Capsicum annuum) was evaluated by sensory and instrumental methods. Hot-air drying decreased levels of the odor compounds (Z)-3-hexenal, 2-heptanone, (Z)-2-hexenal, (E)-2-hexenal, hexanol, (Z)-3-hexanol, (E)-2-hexenol, and linalool, which have

Molecular dynamics investigation on adsorption layer of alcohols at the air/brine interface.

Science.gov (United States)

Nguyen, Cuong V; Phan, Chi M; Ang, Ha M; Nakahara, Hiromichi; Shibata, Osamu; Moroi, Yoshikiyo

2015-01-01

Alcohols are a significant group of surfactants which have been employed extensively in industry to improve the interfacial effects. Recently, the change in surface potential (ΔV) of two isomeric hexanols, methyl isobutyl carbinol (MIBC) and 1-hexanol, was investigated by using an ionizing (241)Am electrode. It clearly showed the opposite effects between MIBC and 1-hexanol in the interfacial zone: one enhanced the presence of cations, whereas the other enhanced the presence of anions. This study employs molecular dynamics simulation to provide new insights into the interactions between alcohol molecules and ions as well as water at the molecular level. The results qualitatively agreed with the experimental data and verified the significance of MIBC branching structure on the molecular arrangement within the interfacial zone. The results also highlighted the role of the second water layer on the interfacial properties.

13 C analysis of aromas and perfumes by a coupled GC-IRMS technique. The case of vanillin and leaf alcohol extracts

International Nuclear Information System (INIS)

Breas, O.; Fourel, F.; Martin, G.J.

1994-01-01

The determination of stable isotope ratios is a precious tool to establish the natural status of flavors and fragrances. Results are presented concerning δ 13 C measurements using gas chromatography-combustion interface-isotope ratio mass spectrometry (GC-C- 13 C IRMS). This technique allows to measure carbon isotope ratios on pure compounds separated by capillary gas chromatography and injected on-line into an isotopic mass spectrometer. δ 13 C measurements carried out on vanilla extracts require only very small quantities of compounds ( 13 C measurements performed on cis-3-hexanol extracted from mint, the difference between natural and synthetic cis-3-hexanol is underlined and it is demonstrated that reproducible isotope ratios may be measured for cis-3-hexanol on mint extracts without purification even if this compound only represents 0.5% of the extract. (authors). 17 refs., 1 fig., 3 tabs

Excess molar enthalpies of binary systems containing 2-octanone, hexanoic acid, or octanoic acid at T = 298.15 K

International Nuclear Information System (INIS)

Liao, Wei-Chen; Lin, Ho-mu; Lee, Ming-Jer

2012-01-01

Highlights: → An isothermal titration calorimeter was used for enthalpy data measurement. → The investigated binary systems contain 2-octanone, hexanoic acid, or octanoic acid. → The excess enthalpies are all positive except for mixtures containing DMSO and DMF. → The Peng-Robinson equation with two parameters yielded the best representation. - Abstract: An isothermal titration calorimeter was used to measure the excess molar enthalpies (H E ) of six binary systems at T = 298.15 K under atmospheric pressure. The systems investigated include (1-hexanol + 2-octanone), (1-octanol + 2-octanone), (1-hexanol + octanoic acid), (1-hexanol + hexanoic acid), {N,N-dimethylformamide (DMF) + hexanoic acid}, and {dimethyl sulfoxide (DMSO) + hexanoic acid}. The values of excess molar enthalpies are all positive except for the DMSO- and the DMF-containing systems. In the 1-hexanol with hexanoic acid or octanoic acid systems, the maximum values of H E are located around the mole fraction of 0.4 of 1-hexanol, but the H E vary nearly symmetrically with composition for other four systems. In addition to the modified Redlich-Kister and the NRTL models, the Peng-Robinson (PR) and the Patel-Teja (PT) equations of state were used to correlate the excess molar enthalpy data. The modified Redlich-Kister equation correlates the H E data to within about experimental uncertainty. The calculated results from the PR and the PT are comparable. It is indicated that the overall average absolute relative deviations (AARD) of the excess enthalpy calculations are reduced from 18.8% and 18.8% to 6.6% and 7.0%, respectively, as the second adjustable binary interaction parameter, k bij , is added in the PR and the PT equations. Also, the NRTL model correlates the H E data to an overall AARD of 10.8% by using two adjustable model parameters.

Intensify dodecylamine adsorption on magnesite and dolomite surfaces by monohydric alcohols

Science.gov (United States)

Zhang, Hao; Liu, Wengang; Han, Cong; Wei, Dezhou

2018-06-01

The flotation of magnesite and dolomite were investigated with the presence of single dodecylamine (DDA) and combined mixtures of DDA and monohydric alcohols, respectively. The adsorption behavior of DDA, butanol, hexanol and octanol on the surface of the two minerals were shown by molecular dynamics simulation, and the results were corresponding with the analysis of zeta potential, measurements of the contact angle and adsorption. Flotation results indicated that part of DDA could be replaced by the three alcohols (butanol, hexanol, octanol) to get better flotation results. Molecular dynamics simulation and the results of zeta potential and contact angle measurements indicated that adsorption of DDA on mineral surfaces could be strengthened by monohydric alcohols.

Characterization of the aroma-active compounds in pink guava (Psidium guajava, L.) by application of the aroma extract dilution analysis.

Science.gov (United States)

Steinhaus, Martin; Sinuco, Diana; Polster, Johannes; Osorio, Coralia; Schieberle, Peter

2008-06-11

The volatiles present in fresh, pink-fleshed Colombian guavas ( Psidium guajava, L.), variety regional rojo, were carefully isolated by solvent extraction followed by solvent-assisted flavor evaporation, and the aroma-active areas in the gas chromatogram were screened by application of the aroma extract dilution analysis. The results of the identification experiments in combination with the FD factors revealed 4-methoxy-2,5-dimethyl-3(2 H)-furanone, 4-hydroxy-2,5-dimethyl-3(2 H)-furanone, 3-sulfanylhexyl acetate, and 3-sulfanyl-1-hexanol followed by 3-hydroxy-4,5-dimethyl-2(5 H)-furanone, ( Z)-3-hexenal, trans-4,5-epoxy-( E)-2-decenal, cinnamyl alcohol, ethyl butanoate, hexanal, methional, and cinnamyl acetate as important aroma contributors. Enantioselective gas chromatography revealed an enantiomeric distribution close to the racemate in 3-sulfanylhexyl acetate as well as in 3-sulfanyl-1-hexanol. In addition, two fruity smelling diastereomeric methyl 2-hydroxy-3-methylpentanoates were identified as the ( R,S)- and the ( S,S)-isomers, whereas the ( S,R)- and ( R,R)-isomers were absent. Seven odorants were identified for the first time in guavas, among them 3-sulfanylhexyl acetate, 3-sulfanyl-1-hexanol, 3-hydroxy-4,5-dimethyl-2(5 H)-furanone, trans-4,5-epoxy-( E)-2-decenal, and methional were the most odor-active.

Selective Protein Extraction from Chlorobium tepidum Chlorosomes Using Detergents. Evidence That CsmA Forms Multimers and Binds Bacteriochlorophyll a

DEFF Research Database (Denmark)

Bryant, Donald A; Vassilieva, Elena V; Frigaard, Niels-Ulrik

2002-01-01

and location of this BChl a are not yet clearly understood. Chlorosomes were treated with sodium dodecyl sulfate (SDS), Lubrol PX, or Triton X-100, separately or in combination with 1-hexanol, and the extracted components were separated from the residual chlorosomes by ultrafiltration on centrifugal filters....... When chlorosomes were treated with low concentrations of SDS, all proteins except CsmA were extracted. However, this treatment did not significantly alter the size and shape of the chlorosomes, did not extract the BChl a, and caused only minor changes in the absorption spectrum of the chlorosomes....... Cross-linking studies with SDS-treated chlorosomes revealed the presence of multimers of the major chlorosome protein, CsmA, up to homooctamers. Extraction of chlorosomes with SDS and 1-hexanol solubilized all ten chlorosome envelope proteins as well as BChl a. Although the size and shape...

The distribution of branched octanols between dodecane and water

International Nuclear Information System (INIS)

Sagert, N.H.; Lau, D.W.P.

1985-01-01

The distribution of four branched chain octanols, 3-ethyl-3-hexanol, 4-ethyl-3-hexanol, 2-ethyl-4-methylpentanol, and 4-octanol, has been measured between dodecane and water. Measurements were made at alcohol concentrations in the dodecane of less than 0.1 mol/dmsup(3), and as a function of temperature from 10 degrees C to 35 degrees C. From these distribution data, standard thermodynamic functions for transfer were calculated. Standard Gibbs energies of transfer from water to dodecane at 25 degrees C were in the range -14.1 to -15.l kJ/mol, whereas the standard enthalpies of transfer at 25 degrees C varied from 29 to 39 kJ/mol. Thus, the change in the standard enthalpy tends to inhibit transfer, but a large standard entropy of transfer results in dodecane being the favoured phase

Biodiesel production through transesterification of triolein with various alcohols in an ultrasonic field

Energy Technology Data Exchange (ETDEWEB)

Hanh, Hoang Duc; Okitsu, Kenji; Nishimura, Rokuro; Maeda, Yasuaki [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan); Dong, Nguyen The [Institute of Environmental Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi (Viet Nam)

2009-03-15

The biodiesel production through transesterification of triolein with various alcohols such as methanol, ethanol, propanol, butanol, hexanol, octanol and decanol was investigated at molar ratio 6:1 (alcohol:triolein) and 25 C in the presence of base catalysts (NaOH and KOH) under ultrasonic irradiation (40 kHz) and mechanical stirring (1800 rot/min) conditions. It was found that the rate of the alkyl ester formation under the ultrasonic irradiation condition was higher than that under the stirring condition. In addition, it was confirmed that the rate depended upon the kind of alcohols; as the number of carbon in alcohol increased, the rate of the ester formation tended to decrease. On the other hand, the secondary alcohols such as 2-propanol, 2-butanol, 2-hexanol, and 2-octanol showed little ester conversion, suggesting that the steric hindrance strongly affected the transesterification of triolein. (author)

A comparative study of fungal and bacterial biofiltration treating a VOC mixture

International Nuclear Information System (INIS)

Estrada, José M.; Hernández, Sergio; Muñoz, Raúl; Revah, Sergio

2013-01-01

Highlights: ► Bacterial biofilter showed better EC and ΔP than fungal biofilter. ► The preferential biodegradation order was: propanal > hexanol > MIBK > toluene. ► Propanal partially inhibited the biodegradation of the rest of VOCs. ► The two-stage biofilter showed a higher stability than the individual units. -- Abstract: Bacterial biofilters usually exhibit a high microbial diversity and robustness, while fungal biofilters have been claimed to better withstand low moisture contents and pH values, and to be more efficient coping with hydrophobic volatile organic compounds (VOCs). However, there are only few systematic evaluations of both biofiltration technologies. The present study compared fungal and bacterial biofiltration for the treatment of a VOC mixture (propanal, methyl isobutyl ketone-MIBK, toluene and hexanol) under the same operating conditions. Overall, fungal biofiltration supported lower elimination capacities than its bacterial counterpart (27.7 ± 8.9 vs 40.2 ± 5.4 g C m −3 reactor h −1 ), which exhibited a final pressure drop 60% higher than that of the bacterial biofilter due to mycelial growth. The VOC mineralization ratio was also higher in the bacterial bed (≈63% vs ≈43%). However, the substrate biodegradation preference order was similar for both biofilters (propanal > hexanol > MIBK > toluene) with propanal partially inhibiting the consumption of the rest of the VOCs. Both systems supported an excellent robustness versus 24 h VOC starvation episodes. The implementation of a fungal/bacterial coupled system did not significantly improve the VOC removal performance compared to the individual biofilter performances

A comparative study of fungal and bacterial biofiltration treating a VOC mixture

Energy Technology Data Exchange (ETDEWEB)

Estrada, José M. [Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Miguel Hidalgo, Delegación Álvaro Obregón (Mexico); Departamento de Ingeniería Química y Tecnología del Medio Ambiente – Universidad de Valladolid, Valladolid (Spain); Hernández, Sergio [Departmento de Procesos e Hidráulica – Universidad Autónoma Metropolitana – Iztapalapa Mexico D.F. Mexico (Mexico); Muñoz, Raúl [Departamento de Ingeniería Química y Tecnología del Medio Ambiente – Universidad de Valladolid, Valladolid (Spain); Revah, Sergio, E-mail: srevah@xanum.uam.mx [Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Artificios 40, Col. Miguel Hidalgo, Delegación Álvaro Obregón (Mexico)

2013-04-15

Highlights: ► Bacterial biofilter showed better EC and ΔP than fungal biofilter. ► The preferential biodegradation order was: propanal > hexanol > MIBK > toluene. ► Propanal partially inhibited the biodegradation of the rest of VOCs. ► The two-stage biofilter showed a higher stability than the individual units. -- Abstract: Bacterial biofilters usually exhibit a high microbial diversity and robustness, while fungal biofilters have been claimed to better withstand low moisture contents and pH values, and to be more efficient coping with hydrophobic volatile organic compounds (VOCs). However, there are only few systematic evaluations of both biofiltration technologies. The present study compared fungal and bacterial biofiltration for the treatment of a VOC mixture (propanal, methyl isobutyl ketone-MIBK, toluene and hexanol) under the same operating conditions. Overall, fungal biofiltration supported lower elimination capacities than its bacterial counterpart (27.7 ± 8.9 vs 40.2 ± 5.4 g C m{sup −3} reactor h{sup −1}), which exhibited a final pressure drop 60% higher than that of the bacterial biofilter due to mycelial growth. The VOC mineralization ratio was also higher in the bacterial bed (≈63% vs ≈43%). However, the substrate biodegradation preference order was similar for both biofilters (propanal > hexanol > MIBK > toluene) with propanal partially inhibiting the consumption of the rest of the VOCs. Both systems supported an excellent robustness versus 24 h VOC starvation episodes. The implementation of a fungal/bacterial coupled system did not significantly improve the VOC removal performance compared to the individual biofilter performances.

Uptake of Organic Gas Phase Species by 1-Methylnaphthalene

Science.gov (United States)

Zhang, H.; Xia, J.; Davidovits, P.; Jayne, J. T.; Kolb, C. E.; Worsnop, D. R.

2002-12-01

Using a droplet train apparatus, the mass accommodation coefficients (α) on 1-methylnapthalene of gas phase m-xylene, ethylbenzene, butylbenzene, α-pinene, γ-terpinene, and 2-methyl-2-hexanol were measured as a function of temperature (265 K to 296 K). 1-methylnapthalene was selected as a surrogate for hydrophobic and aromatic hydrocarbons found in tropospheric aerosols. The mass accommodation coefficients (α) of all the molecules obtained from these measurements exhibit negative temperature dependence. The upper and lower values of α at 265 K and 296 K respectively are: for m-xylene 0.44 and 0.26; for ethylbenzene 0.37 and 0.22; for butylbenzene 0.47 and 0.31; for α-pinene 0.47 and 0.096; for γ-terpinene 0.39 and 0.12; for 2-methyl-2-hexanol 0.44 and 0.26. The uptake measurements also yielded values for the product HDl1/2 for most of the molecules studied (H = Henry's law constant, Dl = liquid phase diffusion coefficient). Using calculated values of Dl the Henry's law constant is obtained, and expressed in the form ln H (M/atm) = -A + B/T. The A and B values for the molecules studied are listed in Table 1. Table 1: A and B values for the Henry's law constant H expressed as ln H (M/atm) = -A + B/T \\ m-xylene: A=7.20, B=4060\\ethylbenzene: A=5.81, B=3660\\butylbenzene: A=16.95, B=7330α-pinene: A=15.69, B=6360\\2-methyl-2-hexanol: A=9.95, B=4760

Interfacial properties and phase behaviour of an ionic microemulsion system

NARCIS (Netherlands)

Kegel, W.K.

1993-01-01

This thesis reports a study of a microemulsion model system composed of the ionic surfactant SDS (Sodium Dodecyl Sulfate), the cosurfactant pentanol and/or hexanol, water, salt and cyclohexane. Depending on the concentrations of the constituent parts, this system may form microemulsion phases and

Phase behaviour of an ionic microemulsion system as a function of the cosurfactant chain length

NARCIS (Netherlands)

Kegel, W.K.; Lekkerkerker, H.N.W.

1993-01-01

The phase behaviour of a microemulsion system consisting of equal volumes of brine and oil, sodium dodecyl sulphate (SDS) as surfactant and alcohols of different chain lengths (pentanol, hexanol and heptanol) as cosurfactant was studied. In the case of pentanol, at low surfactant concentrations and

Eco-friendly methodology for efficient synthesis and scale-up of 2-ethylhexyl-p-methoxycinnamate using Rhizopus oryzae lipase and its biological evaluation.

Science.gov (United States)

Kumar, Vinod; Jahan, Firdaus; Kameswaran, Karthikeya; Mahajan, Richi V; Saxena, Rajendra Kumar

2014-06-01

Lipase-mediated synthesis of phenolic acid esters is a green and economical alternative to current chemical methods. Octyl methoxycinnamate, an important UVB-absorbing compound, was synthesized by the esterification of p-methoxycinnamic acid with 2-ethyl hexanol using Rhizopus oryzae lipase. A molar ratio of 1:2 of p-methoxycinnamic acid and 2-ethyl hexanol was found to give an optimum yield using cyclo-octane (50 ml) as reaction solvent, at a temperature of 45 °C, and 750 U of lipase, resulting in a yield of 91.3 % in 96 h. This reaction was successfully scaled up to 400-ml reaction size where 88.6 %bioconversion was achieved. The synthesized compound was found to have superior antioxidant activity as compared to ascorbic acid. The synthesized compound also exhibited good antimicrobial activity against Escherichia coli, Klebsiella pneumonia, Salmonella typhi, Staphylococcus aures, Candida albicans (yeast), Aspergillus niger, Alternaria solani, and Fussarium oxysporum by well diffusion method in terms of zone of inhibitions (in mm).

Improvements in or relating to ceramic materials

International Nuclear Information System (INIS)

Lane, E.S.

1975-01-01

A method is described for the production of nuclear fuel containing sintered UC or PuC, or a mixture thereof, comprising the steps of precipitating an oxide forming compounds of U or Pu, or a mixture of same, in the form of gel particles containing C, and introducing into the gel particles a compound capable of providing Ni as a sintering aid by contacting the particles with a solution of the Ni compound in an organic solvent. The latter may be a chlorinated hydrocarbon such as trichloroethylene, perchloroethylene of CCl 4 , or an aliphatic alcohol such as n-hexanol, or 2-ethyl hexanol. The Ni compound may be Ni acetonyl acetate or a Ni salt of an organic solvent soluble carboxylic acid. The gel particles are dried by azeotropic distillation from the organic solvent containing the Ni compound, so that the particles absorb the Ni compound. Examples of application of the method are described. (U.K.)

Séparation des mélanges eau-alcool à l'aide du CO2 supercritique : application au mélange éthanol eau Separation of Water-Alcohol Mixtures by Supercritical CO2: Application of the Ethanol- Water Mixture

Directory of Open Access Journals (Sweden)

Fogel W.

2006-11-01

Full Text Available Les marchés accessibles à la technique d'extraction supercritique utilisant le CO2 seront plutôt orientés vers les alcools dérivés de la pétrochimie (isopropanol, butanol secondaire ou du gaz de synthèse (mélange d'alcools allant de l'éthanol à l'hexanol que vers les produits issus des fermentations pour lesquels la sélectivité de la séparation est théoriquement insuffisante et la concentration en alcool dans le moût fermenté trop faible. Markets for the supercritical extraction technique using CO2 will mainly be aimed for alcohols derived from petrochemicals (isopropanol, secondary butanol or from synthetic gas (mixture of alcohols ranging from ethanol to hexanol rather than for products from fermentations for which separation selectivity is theoretically insufficient and the alcohol concentration in the wort much too weak.

Confinement for More Space

DEFF Research Database (Denmark)

Kipnusu, Wycliffe K.; Elsayed, Mohamed; Kossack, Wilhelm

2015-01-01

Broadband dielectric spectroscopy and positron annihilation lifetime spectroscopy are employed to study the molecular dynamics and effective free volume of 2-ethyl-1-hexanol (2E1H) in the bulk state and when confined in unidirectional nanopores with average diameters of 4, 6, and 8 nm. Enhanced α...

Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles

Science.gov (United States)

The GLVs, such as 1-hexanol and (Z)-3-hexen-1-ol, elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relative weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactom...

Comparison of the neurotoxicities between volatile organic compounds and fragrant organic compounds on human neuroblastoma SK-N-SH cells and primary cultured rat neurons

Directory of Open Access Journals (Sweden)

Yasue Yamada

2015-01-01

Full Text Available These are many volatile organic compounds (VOCs that are synthesized, produced from petroleum or derived from natural compounds, mostly plants. Fragrant and volatile organic compounds from plants have been used as food additives, medicines and aromatherapy. Several clinical and pathological studies have shown that chronic abuse of VOCs, mainly toluene, causes several neuropsychiatric disorders. Little is known about the mechanisms of neurotoxicity of the solvents. n-Octanal, nonanal, and 2-ethyl-1-hexanol, which are used catalyzers or intermediates of chemical reactions, are released into the environment. Essential oils have the functions of self-defense, sterilization, and antibiosis in plants. When volatile organic compounds enter the body, there is the possibility that they will pass through the blood–brain barrier (BBB and affect the central nervous system (CNS. However, the direct effects of volatile organic compounds on neural function and their toxicities are still unclear. We compared the toxicities of n-octanal, nonanal and 2-ethyl-1-hexanol with those of five naturally derived fragrant organic compounds (FOCs, linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and n-phenethyl alcohol. MTT assay of human neuroblastoma SK-N-SH cells showed that the IC50 values of linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and phenethyl alcohol were 1.33, 2.3, >5, >5, and 2.39 mM, respectively, and the IC50 values of toluene, n-octanal, nonanal and 2-ethyl-1-hexanol were 850, 37.2, 8.31 and 15.1 μM, respectively. FOCs showed lower toxicities than those of VOCs. These results indicate that FOCs are safer than other compounds.

Communication

DEFF Research Database (Denmark)

Adrjanowicz, Karolina; Jakobsen, Bo; Hecksher, Tina

2015-01-01

In this paper, we present results of dielectric and shear-mechanical studies for amine (2-ethyl-1-hexylamine) and thiol (2-ethyl-1-hexanethiol) derivatives of the monohydroxy alcohol, 2-ethyl-1-hexanol. The amine and thiol can form hydrogen bonds weaker in strength than those of the alcohol. The ...

An evaporation-assisted dispersive liquid-liquid microextraction technique as a simple tool for high performance liquid chromatography tandem-mass spectrometry determination of insecticides in wine.

Science.gov (United States)

Timofeeva, Irina; Kanashina, Daria; Moskvin, Leonid; Bulatov, Andrey

2017-08-25

A sample pre-treatment technique based on evaporation-assisted dispersive liquid-liquid microextraction (EVA-DLLME), followed by HPLC-MS/MS has been developed for the determination of organophosphate insecticides (malathion, diazinon, phosalone) in wine samples. The procedure includes the addition of mixture of organic solvents (with density higher than water), consisting of the extraction (low density) and volatile (high density) solvents, to aqueous sample followed by heating of the mixture obtained, what promotes the volatile solvent evaporation and moving extraction solvent droplets from down to top of the aqueous sample and, as a consequence, microextraction of target analytes. To initiate the evaporation process an initiator is required. It was established that hexanol (extraction solvent) and dichloromethane (volatile solvent) mixture (1:1, v/v) provides effective microextraction of the insecticides from wine samples with recovery from 92 to 103%. The conditions of insecticides' microextraction such as selection of extraction solvent, ratio of hexanol/dichloromethane and hexanol/sample, type and concentration of initiator, and effect of ethanol as one of the main components of wine have been studied. Under optimal experimental conditions the linear detection ranges were found to be 10 -7 -10 -3 gL -1 for malathion, 10 -9 -10 -4 gL -1 for diazinon, and 10 -6 -10 -2 gL -1 for phosalone. The LODs, calculated from a blank test, based on 3σ, found to be 3×10 -8 gL -1 for malathion, 3×10 -10 gL -1 for diazinon and 3×10 -7 gL -1 for phosalone. The advantages of EVA-DLLME are the rapidity, simplicity, high sample throughput and low cost. As an outcome, the analytical results agreed fairly well with the results obtained by a reference GC-MS method. Copyright © 2017 Elsevier B.V. All rights reserved.

Where is the TMT? GC-MS analyses of fox feces and behavioral responses of rats to fear-inducing odors.

Science.gov (United States)

Rampin, Olivier; Jerôme, Nathalie; Saint-Albin, Audrey; Ouali, Christian; Boué, Frank; Meunier, Nicolas; Nielsen, Birte L

2018-02-02

TMT (2,5-dihydro-2,4,5-trimethylthiazoline) is known as a component of fox feces inducing fear in rodents. However, no recent chemical analyses of fox feces are available, and few studies make direct comparisons between TMT and fox feces. Fox feces from 3 individuals were used to prepare 24 samples to be analyzed for the presence of TMT using gas chromatography-mass spectrometry (GC-MS). When TMT was added in low amounts (50-2000 nmol/g), TMT was detected in 10 out of 11 samples. When no TMT was added, TMT was detected in only 1 out of 13 samples. In a second experiment, we tested the behavioral response of male Brown Norway (BN) and Wistar rats to either fox feces, a low amount of TMT (0.6 nmol) or 1-hexanol. TMT induced freezing in the rats, but fox feces induced significantly more freezing episodes and longer total duration of freezing in both rat strains. In experiment 3, male BN rats were exposed over several days to fox feces, rat feces, 1-hexanol, cadaverine, 2-phenylethylamine, and TMT, one odor at a time. Fox feces induced significantly more freezing episodes of a longer total duration than any of the other odors, with rat feces and 1-hexanol giving rise to the lowest amount of freezing. This finding, together with our inability to verify the presence of TMT in fox feces, indicates that the concentration of TMT in our fox feces samples was below 50 nmol/g. It may also be that other compounds in fox feces play a role in its fear-inducing properties. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

On the smell of Composition C-4.

Science.gov (United States)

Kranz, William; Kitts, Kelley; Strange, Nicholas; Cummins, Joshua; Lotspeich, Erica; Goodpaster, John

2014-03-01

In efforts to locate hidden explosives, humans have had few allies as valuable as the explosives-detecting canine. The unrivaled sensitivity and selectivity of the canine nose have combined to make these animals an attractive choice for law enforcement, military, and private security applications. Although the efficacy of trained detector dogs is well-established, the question of which chemical compounds are responsible for causing a dog to recognize a particular odor and alert to it remains a subject of debate for several explosive formulations--including, perhaps most notably, Composition C-4. Previous studies have indicated that cyclohexanone, 2,3-dimethyl-2,3-dinitrobutane, and 2-ethyl-1-hexanol are the chemicals that may cause canines to alert to C-4. This has led to the suggestion that these substances could be used as a substitute for genuine C-4 in the training, testing, and maintenance of explosives-detecting canines. In this paper, we present an alternative view. Using gas chromatography-mass spectrometry with solid phase microextraction as a pre-concentration technique, we have discovered that 2-ethyl-1-hexanol off-gasses not only from C-4, but also from benign sources, such as the common plasticizers bis(2-ethylhexyl)adipate, bis(2-ethylhexyl)sebacate, and bis(2-ethylhexyl)phthalate; as well as several plasticized items common to our everyday world, including PVC tile, PVC pipe, electrical tape, and credit cards. This observation may potentially discourage the use of 2-ethyl-1-hexanol for training purposes. We also present the results of our own canine field trials focused on the detection of C-4. Through the use of contingency tables and statistical testing, we demonstrate the failure of trained law enforcement dogs in our study to respond in any significant way to these potential odor compounds. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Volatile compounds in medlar fruit (Mespilus germanica L. at two ripening stages

Directory of Open Access Journals (Sweden)

Veličković Milovan M.

2013-01-01

Full Text Available Medlar is the fruit of Mespilus germanica L. in the family of Rosaceae. The fruit can be eaten only if ‘bletted’ (softened by frost or longer storage. The effect of the maturation stages on the volatile compounds of the medlar fruit was investigated during two different stages. Volatile flavour substances were isolated from the minced pulp of unripe and full ripe medlar fruits by simultaneous steam distillation extraction (SDE with methilen chloride as the extracting solvent. The concentrate was analysed by GC-FID-MS. Hexanoic and hexadecanoic acids were the predominant acids, hexanal and (E-2-hexenal were the predominant aldehydes, (Z-3-hexenol and hexanol were the predominant alcohols, with p-cymene, terpinen-4-ol, and γ-terpiene (the terpenes responsible for the characteristic medlar flavour being also present. The C6 aliphatic compounds, such as hexanal and (E-2-hexenal, were observed as the major volatile constituents in the green stage. In contrast, hexanol and (Z-3-hexenol were the main volatiles in ripe fruits.

Investigation on molecular interactions of binary mixtures of isobutanol with 1-alkanols (C1 - C6) at different temperatures. Application of the Peng-Robinson-Stryjek-Vera (PSRV) equation of state (EOS)

Science.gov (United States)

Khanlarzadeh, K.; Iloukhani, H.; Soleimani, M.

2017-07-01

Densities were measured for binary mixtures of isobutanol with 1-alkanols, namely: methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-hexanol at the temperatures of (288.15, 298.15 and 308.15) K and ambient pressure. Excess molar volumes, VmE , thermal expansion coefficients α, excess thermal expansion coefficients αE, and isothermal coefficients of pressure excess molar enthalpy, (∂HmE / ∂ P) T , x , were derived from the experimental data and the computed results were fitted to the Redlich-Kister equation. The Peng-Robinson-Stryjek-Vera (PRSV) equation of state was applied, in combination with simple mixing rules to predict the excess molar volume. The VmE results were positive for the mixtures of isobutanol with methanol, ethanol, 1-propanol, 1-butanol, and negative for isobutanol with 1-pentanol and 1-hexanol over the whole composition range. The results showed very small deviations from the behavior of ideal solutions in these mixtures and were analyzed to discuss the nature and strength of intermolecular interactions.

Preparation of LDPE/LNR Blend Via Emulsion Dispersion

International Nuclear Information System (INIS)

Rusli Daik; Yee Lee Ching

2007-01-01

Low density polyethylene (LDPE)/ liquid natural rubber (LNR) blends with the composition of 100LDPE/ 0LNR, 70LDPE/ 30LNR, 60LDPE/ 40LNR and 40LDPE/ 60LNR were prepared via dispersion of LDPE and LNR emulsion. LNR was obtained via photochemical sensitization of natural rubber (NR). Emulsion of LNR was prepared by using sodium dodecyl sulfate (SDS) and 1-hexanol as the emulsifier and co- emulsifier respectively. Emulsion of LDPE was prepared in the same way by using LDPE solution in carbon tetrachloride, SDS and 1-hexanol. LDPE/ LNR blends were prepared via mixing of LNR and LDPE emulsions. Mechanical properties of the blends were analyzed by tensile, hardness and impact test. Optimum mechanical properties were observed for composite with composition of 60LDPE/ 40LNR that showed the maximum value of stress and strain. The glass transition temperature, T g , of the blends as obtained from differential scanning calorimetric (DSC) showed that the blends were homogeneous. Morphology study by using scanning electron microscopy (SEM) also indicates the homogeneity of LDPE/ LNR blends produced. (author)

Method to fabricate block fuel elements for high temperature reactors

International Nuclear Information System (INIS)

Hrovat, M.; Rachor, L.

1977-01-01

The fabrication of block fuel elements for gas-cooled high temperature reactors can be improved upon by adding 0.2 to 2 wt.% of a hydrocarbon compound to the lubricating mixture prior to pressing. Hexanol or octanol are named as substances. The dimensional accuracy of the block is thus improved. 2 examples illustrate the method. (RW) [de

Method to fabricate block fuel elements for high temperature reactors

International Nuclear Information System (INIS)

Hrovat, M.; Rachor, L.

1978-01-01

The fabrication of block fuel elements for gas-cooled high temperature reactors can be improved upon by adding 0.2 to 2 wt.% of a hydrocarbon compound to the lubricating mixture prior to pressing. Hexanol or octanol are named as substances. The dimensional accuracy of the block is thus improved. 2 examples illustrate the method. (orig./PW)

Study of volatile alcohols and esters from the subcutaneous fat during ripening of Iberian dry-cured ham. A tool for predicting the dry-curing time; Estudio de los alcoholes y ésteres volátiles de la grasa subcutánea durante la maduración del jamón ibérico. Una herramienta para predecir el tiempo de curación

Energy Technology Data Exchange (ETDEWEB)

Narvaez-Rivas, M.; Gallardo, E.; Leon-Camacho, M.

2016-07-01

Variations in the amounts of volatile alcohols and esters from subcutaneous fat have been assessed during the dry-curing process (1022 days) of Iberian ham according to a purge and trap-gas chromatography-mass spectroscopy method, using the same hams throughout the process. During processing time, the subcutaneous adipose tissues of ten hams obtained from five Iberian pigs fed on acorns and pasture were sampled and analyzed once per month. Fifteen alcohols and five esters have been identified. All volatile alcohols detected in this work have been previously identified by other authors on Iberian ham, except 3-buten-2-ol, 5-methyl-3-hexanol and 2-isononanol. A linear discriminant analysis (LDA) was applied and the two discriminant functions were obtained using backward stepwise analysis retaining the following variables: butyl ester formic acid, 1-penten-3-ol, methyl ester 2-propenoic acid, 5-methyl-3-hexanol, 1-nonanol, ethyl ester pentanoic acid, ethyl ester hexanoic acid, 2-isononanol, ethanol and 3-buten-2-ol. A complete separation among the three periods was obtained, suggesting that the retained variables are powerful descriptors to distinguish samples from these three dry-curing stages. [Spanish] Se han evaluado durante el proceso de curación (1022 días), las variaciones en los contenidos de alcoholes y ésteres volátiles de la grasa subcutánea del jamón ibérico mediante la técnica de acoplamiento purga y trampa- cromatografía de gases-espectrometría de masas, utilizando los mismos jamones a lo largo de todo el proceso. Durante el tiempo de curación se muestreó y analizó una vez al mes el tejido adiposo subcutáneo de diez jamones procedente de cinco cerdos ibéricos alimentados con bellotas y pastos. Se han identificado quince alcoholes y cinco ésteres volátiles. Todos los alcoholes descritos en este trabajo han sido identificados previamente por otros autores en el jamón ibérico, excepto el 3-buten-2-ol, el 5-metil-3-hexanol y el 2

Thermodynamic study of fluid in terms of equation of state containing physical parameters

International Nuclear Information System (INIS)

Khasare, S. B.

2015-01-01

We introduce a simple condition for one mole fluid by considering the thermodynamics of molecules pointing towards the effective potential for the cluster. Efforts are made to estimate new physical parameter f in liquid state using the equation of state containing only two physical parameters such as the hard sphere diameter and binding energy. The temperature dependence of the structural properties and the thermodynamic behavior of the clusters are studied. Computations based on f predict the variation of numbers of particles at the contact point of the molecular cavity (radial distribution function). From the thermodynamic profile of the fluid, the model results are discussed in terms of the cavity due to the closed surface along with suitable energy. The present calculation is based upon the sample thermodynamic data for n-hexanol, such as the ultrasonic wave, density, volume expansion coefficient, and ratio of specific heat in the liquid state, and it is consistent with the thermodynamic relations containing physical parameters such as size and energy. Since the data is restricted to n-hexanol, we avoid giving the physical meaning of f, which is the key parameter studied in the present work. (paper)

Markers of typical red wine varieties from the Valley of Tulum (San Juan-Argentina) based on VOCs profile and chemometrics.

Science.gov (United States)

Fabani, María P; Ravera, Mario J A; Wunderlin, Daniel A

2013-11-15

We studied the VOCs profile of three red wine varieties, produced in the Valley of Tulum (San Juan-Argentina), over 4 consecutive years. Our main goal was to verify if different wine varieties could be differentiated from their VOCs profile, considering changes induced by their age, the yeast inoculated and the type of alcoholic fermentation, establishing those compounds that could be used as chemical markers of a particular variety. Stepwise LDA of selected VOCs allowed 100% differentiation between studied wines, showing that high levels of 1-hexanol were characteristic for Malbec, while low level of ethyl caproate was characteristic for Bonarda. Using controlled fermentations, 1-hexanol, a pre-fermentative VOC, presented a similar trend in wines produced from different yeast; while other fermentative VOCs, like ethyl caproate and ethyl caprilate, presented lower levels for Bonarda but also for Syrah. To our knowledge, this is the first report on characterization of VOCs from Bonarda. Additionally, the quantitative analysis of VOCs profile, coupled to chemometrics, present a good alternative to differentiate wines from different varieties and also for studying wine fermentation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Improving the indoor air quality by using a surface emissions trap

Science.gov (United States)

Markowicz, Pawel; Larsson, Lennart

2015-04-01

The surface emissions trap, an adsorption cloth developed for reducing emissions of volatile organic compounds and particulate matter from surfaces while allowing evaporation of moisture, was used to improve the indoor air quality of a school building with elevated air concentrations of 2-ethyl-1-hexanol. An improvement of the perceived air quality was noticed a few days after the device had been attached on the PVC flooring. In parallel, decreased air concentrations of 2-ethyl-1-hexanol were found as well as a linear increase of the amounts of the same compound adsorbed on the installed cloth as observed up to 13 months after installation. Laboratory studies revealed that the performance of the device is not affected by differences in RH (35-85%), temperature (30-40 °C) or by accelerated aging simulating up to 10 years product lifetime, and, from a blinded exposure test, that the device efficiently blocks chemical odors. This study suggests that the device may represent a fast and efficient means of restoring the indoor air quality in a building e.g. after water damage leading to irritating and potentially harmful emissions from building material surfaces indoors.

Transgalactosylation/Hydrolysis Ratios of Various β-Galactosidases Catalyzing Alkyl-β-Galactoside Synthesis in Single-Phased Alcohol Media

Directory of Open Access Journals (Sweden)

Eleonora Winkelhausen

2008-01-01

Full Text Available Three microbial galactosidases, Aspergillus oryzae, Escherichia coli and Kluyveromyces marxianus β-galactosidase, were used as catalysts for transgalactosylation synthesis of alkyl-β-galactosides in single-phased alcohol media. Their selectivity towards different alcohol nucleophiles was quantified by determining the transgalactosylation/hydrolysis ratio in the water/alcohol mixtures containing water in concentrations below the level of saturation. p-Nitrophenyl-β-galactoside was used as a glycosyl donor at a concentration of 10 mM. Both the total reaction rate (transgalactosylation+hydrolysis and the ratio between the transgalactosylation (alcoholysis and hydrolysis increased with the increase of water activity. Although the A. oryzae β-galactosidase showed relatively low total activity (3.13 μmol/(min·mg protein, it exhibited the highest selectivity towards the hexanol nucleophile among the examined enzymes (0.65. The selectivity values in all the examined cases were below one, which implies that the hydrolysis, and not the synthesis, was the dominating reaction. The total reaction rate (transgalactosylation+hydrolysis was strongly affected by the water activity, and for the specific water activity in the different alcohols, it increased in the following order: n-octanol, n-hexanol, n-butanol.

Redox self-sufficient whole cell biotransformation for amination of alcohols.

Science.gov (United States)

Klatte, Stephanie; Wendisch, Volker F

2014-10-15

Whole cell biotransformation is an upcoming tool to replace common chemical routes for functionalization and modification of desired molecules. In the approach presented here the production of various non-natural (di)amines was realized using the designed whole cell biocatalyst Escherichia coli W3110/pTrc99A-ald-adh-ta with plasmid-borne overexpression of genes for an l-alanine dehydrogenase, an alcohol dehydrogenase and a transaminase. Cascading alcohol oxidation with l-alanine dependent transamination and l-alanine dehydrogenase allowed for redox self-sufficient conversion of alcohols to the corresponding amines. The supplementation of the corresponding (di)alcohol precursors as well as amino group donor l-alanine and ammonium chloride were sufficient for amination and redox cofactor recycling in a resting buffer system. The addition of the transaminase cofactor pyridoxal-phosphate and the alcohol dehydrogenase cofactor NAD(+) was not necessary to obtain complete conversion. Secondary and cyclic alcohols, for example, 2-hexanol and cyclohexanol were not aminated. However, efficient redox self-sufficient amination of aliphatic and aromatic (di)alcohols in vivo was achieved with 1-hexanol, 1,10-decanediol and benzylalcohol being aminated best. Copyright © 2014 Elsevier Ltd. All rights reserved.

Volatile metabolites associated with one aflatoxigenic and one nontoxigenic Aspergillus flavus strain grown on two different substrates

Directory of Open Access Journals (Sweden)

Z. Jurjevic

2009-01-01

Full Text Available Aflatoxigenic and non-toxigenic Aspergillus flavus strains were grown on corn and on peanut substrates. Microbial volatile organic compounds (MVOCS were collected by trapping headspace volatiles using thermal desorption tubes (TDT packed with Tenax® TA and Carbotrap™ B. Samples were collected at various fungal growth stages. Trapped compounds were thermally desorbed from the adsorbent tubes, separated by gas chromatography, and identified by mass spectrometry. The fungal stage did not have many differences in the MVOCs but the concentrations of some volatiles changed over time depending on the substrate. Volatiles that were associated with both the aflatoxigenic A. flavus strain and the nontoxigenic strain on both substrates included: ethanol, 1-propanol, butanal, 2-methyl-1-propanol, 3-methylfuran, ethyl acetate, 1-butanol, 3-methylbutanal, 3-methyl-1-butanol, propanoic acid-2-methyl-ethyl-ester, 2-methyl-1-butanol, 1-pentanol, 2-pentanol, 3-methyl-3-buten-1-ol, benzaldehyde, 3-octanone, 2-ethyl-1-hexanol and octane. Volatiles that were associated only with the aflatoxigenic A. flavus strain included: dimethyl disulfide and nonanal. Volatiles that were associated only with the nontoxigenic A. fl avus strain included: hexanal, 1-hexanol, 1-octene-3-ol, 1-octen-3-one and 2-pentyl furan.

Increase in volatilization of organic compounds using air sparging through addition in alcohol in a soil-water system.

Science.gov (United States)

Chao, Huan-Ping; Hsieh, Lin-Han Chiang; Tran, Hai Nguyen

2018-02-15

This study developed a novel method to promote the remediation efficiency of air sparging. According to the enhanced-volatilization theory presented in this study, selected alcohols added to groundwater can highly enhance the volatilization amounts of organic compounds with high Henry's law constants. In this study, the target organic compounds consisted of n-hexane, n-heptane, benzene, toluene, 1,1,2-trichloroethane, and tetrachloroethene. n-pentanol, n-hexanol, and n-heptanol were used to examine the changes in the volatilization amounts of organic compounds in the given period. Two types of soils with high and low organic matter were applied to evaluate the transport of organic compounds in the soil-water system. The volatilization amounts of the organic compounds increased with increasing alcohol concentrations. The volatilization amounts of the test organic compounds exhibited a decreasing order: n-heptanol>n-hexanol>n-pentanol. When 10mg/L n-heptanol was added to the system, the maximum volatilization enhancement rate was 18-fold higher than that in distilled water. Samples of soil with high organic matter might reduce the volatilization amounts by a factor of 5-10. In the present study, the optimal removal efficiency for aromatic compounds was approximately 98%. Copyright © 2017 Elsevier B.V. All rights reserved.

Subcellular localization of secondary lipid metabolites including fragrance volatiles in carnation petals

International Nuclear Information System (INIS)

Hudak, K.A.; Thompson, J.E.

1997-01-01

Pulse-chase labeling of carnation (Dianthus caryophyllus L. cv Improved White Sim) petals with [14C]acetate has provided evidence for a hydrophobic subcompartment of lipid-protein particles within the cytosol that resemble oil bodies, are formed by blebbing from membranes, and are enriched in lipid metabolites (including fragrance volatiles) derived from membrane fatty acids. Fractionation of the petals during pulse-chase labeling revealed that radiolabeled fatty acids appear first in microsomal membranes and subsequently in cytosolic lipid-protein particles, indicating that the particles originate from membranes. This interpretation is supported by the finding that the cytosolic lipid-protein particles contain phospholipid as well as the same fatty acids found in microsomal membranes. Radiolabeled polar lipid metabolites (methanol/ water-soluble) were detectable in both in situ lipid-protein particles isolated from the cytosol and those generated in vitro from isolated radiolabeled microsomal membranes. The lipid-protein particles were also enriched in hexanal, trans-2-hexenal, 1-hexanol, 3-hexen-1-ol, and 2-hexanol, volatiles of carnation flower fragrance that are derived from membrane fatty acids through the lipoxygenase pathway. Therefore, secondary lipid metabolites, including components of fragrance, appear to be formed within membranes of petal tissue and are subsequently released from the membrane bilayers into the cytosol by blebbing of lipid-protein particles

Facile hydrothermal method for synthesizing nitrogen-doped graphene nanoplatelets using aqueous ammonia: dispersion, stability in solvents and thermophysical performances

Science.gov (United States)

Shafiah Shazali, Siti; Amiri, Ahmad; Zubir, Mohd. Nashrul Mohd; Rozali, Shaifulazuar; Zakuan Zabri, Mohd; Sabri, Mohd Faizul Mohd

2018-03-01

A simple and green approach has been developed to synthesize nitrogen-doped graphene nanoplatelets (N-doped GNPs) for mass production with a very high stability in different solvents e.g. water, ethylene glycol, methanol, ethanol, and 1-hexanol. The strategy is based on mild oxidation of GNPs using hydrogen peroxide and doping with nitrogen using hydrothermal process. The modification of N-doped GNPs was demonstrated by FTIR, TGA, XPS, Raman spectroscopy and high resolution-transmission electron microscope (HRTEM). Further study was carried out by using N-doped GNPs as an additive to prepare different colloidal dispersions. Water-based N-doped GNPs, methanol-based N-doped GNPs, ethanol-based N-doped GNPs, ethylene-glycol based N-doped GNPs and 1-hexanol-based N-doped GNPs dispersions at 0.01 wt.% shown great colloidal stabilities, indicating 17%, 29%, 33%, 18%, and 43% sedimentations after a 15-days period, respectively. The thermophysical properties e.g., viscosity and thermal conductivity of water-based N-doped GNP nanofluids were also evaluated for different weight concentrations of 0.100, 0.075, 0.050, and 0.025 wt.%. Through this, it is found that the obtained dispersions have great potential to be used as working fluids for industrial thermal systems.

Enzymes extracted from apple peels have activity in reducing higher alcohols in Chinese liquors.

Science.gov (United States)

Han, Qi'an; Shi, Junling; Zhu, Jing; Lv, Hongliang; Du, Shuangkui

2014-10-01

As the unavoidable byproducts of alcoholic fermentation, higher alcohols are unhealthy compounds widespread in alcoholic drinks. To investigate the activity of apple crude enzymes toward higher alcohols in liquors, five kinds of apple peels, namely, Fuji, Gala, Golden Delicious, Red Star, and Jonagold, were chosen to prepare enzymes, and three kinds of Chinese liquors, namely, Xifeng (containing 45% ethanol), Taibai (containing 50% ethanol), and Erguotou (containing 56% ethanol), were tested. Enzymes were prepared in the forms of liquid solution, powder, and immobilized enzymes using sodium alginate (SA) and chitosan. The treatment was carried out at 37 °C for 1 h. The relative amounts of different alcohols (including ethanol, 1-propanol, isobutanol, 1-butanol, isoamylol, and 1-hexanol) were measured using gas chromatography (GC). Conditions for preparing SA-immobilized Fuji enzymes (SA-IEP) were optimized, and the obtained SA-IEP (containing 0.3 g of enzyme) was continuously used to treat Xifeng liquor eight times, 20 mL per time. Significant degradation rates (DRs) of higher alcohols were observed at different degrees, and it also showed enzyme specificity according to the apple varieties and enzyme preparations. After five repeated treatments, the DRs of the optimized Fuji SA-IEP remained 70% for 1-hexanol and >15% for other higher alcohols.

Development of An Impedimetric Aptasensor for the Detection of Staphylococcus aureus

OpenAIRE

Reich, Peggy; Stoltenburg, Regina; Strehlitz, Beate; Frense, Dieter; Beckmann, Dieter

2017-01-01

In combination with electrochemical impedance spectroscopy, aptamer-based biosensors are a powerful tool for fast analytical devices. Herein, we present an impedimetric aptasensor for the detection of the human pathogen Staphylococcus aureus. The used aptamer targets protein A, a surface bound virulence factor of S. aureus. The thiol-modified protein A-binding aptamer was co-immobilized with 6-mercapto-1-hexanol onto gold electrodes by self-assembly. Optimization of the ratio of aptamer to 6-...

Mass Transfer from Evaporating 1-Hexanol Drop by Using Two Experimental Technique

Czech Academy of Sciences Publication Activity Database

Schwarz, Jaroslav; Smolík, Jiří

1997-01-01

Roč. 24, 4-6 (1997), s. 516-525 ISSN 2152-5102 Keywords : drop evaporation * mass transfer Subject RIV: CF - Physical ; Theoretical Chemistry http://www.scopus.com/record/display.url?eid=2-s2.0-7944237270&origin=resultslist&sort=plf-f&src=s&nlo=&nlr=&nls=&imp=t&sid=jBuCpGzHSwCT1nqGqh_K8Qd%3a80&sot=br&sdt=a&sl=56&s=SOURCE-ID%2820447%29+ AND +PUBYEAR+IS+1997+ AND +NOT+DOCTYPE%28ip%29&relpos=26&relpos=6&searchTerm=SOURCE-ID(20447) AND PUBYEAR IS 1997 AND NOT DOCTYPE(ip).

Set-Up and Validation of a Dynamic Solid/Gas Bioreactor

KAUST Repository

Lloyd-Randol, Jennifer D.

2012-05-01

The limited availability of fossil resourses mandates the development of new energy vectors, which is one of the Grand Challenges of the 21st Century [1]. Biocatalytic energy conversion is a promising solution to meet the increased energy demand of industrialized societies. Applications of biocatalysis in the gas-phase are so far limited to production of fine chemicals and pharmaceuticals. However, this technology has the potential for large scale biocatalytic applications [2], e.g. for the formation of novel energy carriers. The so-called solid/gas biocatalysis is defined as the application of a biocatalyst immobilized on solid-phase support acting on gaseous substrates [3]. This process combines the advantages of bio-catalysis (green chemistry, mild reaction conditions, high specicity & selectivity) and heterogeneous dynamic gas-phase processes (low diffusion limitation, high conversion, simple scale-up). This work presents the modifications of a PID Microactivity Reference reactor in order to make it suitable for solid/gas biocatalysis. The reactor design requirements are based on previously published laboratory scale solid/gas systems with a feed of saturated vapors [4]. These vapors are produced in saturation flasks, which were designed and optimized during this project. Other modifications included relocation of the gas mixing chamber, redesigning the location and heating mechanism for the reactor tube, and heating of the outlet gas line. The modified reactor system was verified based on the Candida antarctica lipase B catalyzed transesterication of ethyl acetate with 1-hexanol to hexyl acetate and ethanol and results were compared to liquid-phase model reactions. Products were analyzed on line by a gas chromatograph with a flame ionization detector. C. antarc- tica physisorbed on silica particles produced a 50% conversion of hexanol at 40 C in the gas-phase. A commercial immobilized lipase from Iris Biotech produced 99% and 97% conversions of hexanol in

A comparative analysis on combustion and emissions of some next generation higher-alcohol/diesel blends in a direct-injection diesel engine

International Nuclear Information System (INIS)

Rajesh Kumar, B.; Saravanan, S.; Rana, D.; Nagendran, A.

2016-01-01

Highlights: • Four higher-alcohols namely, iso-butanol, n-pentanol, n-hexanol and n-octanol, were used. • Iso-butanol/diesel blend presented longest ignition delay, highest peak pressures and peak heat release rates. • NOx emissions were high for n-pentanol/diesel and n-hexanol/diesel blends at high load conditions. • Smoke opacity is highest for n-octanol/diesel blend and lowest for iso-butanol/diesel blend. • HC emissions are high for iso-butanol/diesel and n-pentanol/diesel blends. - Abstract: Higher alcohols are attractive next generation biofuels that can be extracted from sugary, starchy and ligno-cellulosic biomass feedstocks using sustainable pathways. Their viability for use in diesel engines has greatly improved ever since extended bio-synthetic pathways have achieved substantial yields of these alcohols using engineered micro-organisms. This study sets out to compare and analyze the effects of some higher alcohol/diesel blends on combustion and emission characteristics of a direct-injection diesel engine. Four test fuels containing 30% by vol. of iso-butanol, n-pentanol, n-hexanol and n-octanol (designated as ISB30, PEN30, HEX30 and OCT30 respectively) in ultra-low sulfur diesel (ULSD) were used. Results indicated that ISB30 experienced longest ignition delay and produced highest peaks of pressure and heat release rates (HRR) compared to other higher-alcohol blends. The ignition delay, peak pressure and peak HRR are found to be in the order of (from highest to lowest): ISB30 > PEN30 > HEX30 > OCT30 > ULSD. The combustion duration (CD) for all test fuels is in the sequence (from shortest to longest): ISB30 OCT30 > HEX30 > PEN30 > ISB30. HC emissions are high for ISB30 and PEN30 while it decreased favorably for HEX30 and OCT30. It was of the order (from highest to lowest): ISB30 > PEN30 > ULSD > HEX30 > OCT30. CO emissions of the blends followed the trend of smoke emissions and remained lower than ULSD with the following order (from highest to

Measurement and correlation of solubility of trans-resveratrol in 11 solvents at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K

Energy Technology Data Exchange (ETDEWEB)

Sun Xilan; Peng Bin [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Yan Weidong [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China)], E-mail: yanweidong@zju.edu.cn

2008-04-15

The solubilities of trans-resveratrol in methanol, ethanol, 1-propanol, 2- propanol, 1-butanol, 1-pentanol, 1-hexanol, ethyl acetate, tetrahydrofuran, acetone, and water (pH 6.0) solvents were measured at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K. The solubilities of trans-resveratrol in selected solvents increase with temperature, but decrease with increasing the number of carbon in alcohol solvents. The experimental data were correlated using a thermodynamic equation.

Measurement and correlation of solubility of trans-resveratrol in 11 solvents at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K

International Nuclear Information System (INIS)

Sun Xilan; Peng Bin; Yan Weidong

2008-01-01

The solubilities of trans-resveratrol in methanol, ethanol, 1-propanol, 2- propanol, 1-butanol, 1-pentanol, 1-hexanol, ethyl acetate, tetrahydrofuran, acetone, and water (pH 6.0) solvents were measured at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K. The solubilities of trans-resveratrol in selected solvents increase with temperature, but decrease with increasing the number of carbon in alcohol solvents. The experimental data were correlated using a thermodynamic equation

Increasing alcohol yield in sugar fermentation

Energy Technology Data Exchange (ETDEWEB)

Colin, P

1962-02-20

The yield of alcohol from yeast fermentations of sugar solutions is increased 1.5 to 5% by the addition of 0.1 to 0.5 parts by volume of a monohydric saturated aliphatic alcohol of at least 6 C atoms in a straight chain such as hexanol or heptanol, or branched chain, such as 2-ethylbutanol or 2-ethylhexanol, or a mixture consisting mostly of C/sub 7/, C/sub 8/, C/sub 9/, or C/sub 10/ alcohols.

Kinetic model for reactivity in quaternary water-in-oil microemulsions.

Science.gov (United States)

García-Río, Luis; Hervella, Pablo

2006-11-06

A study was carried out on the nitrosation of piperazine (PIP) and N-methylbenzylamine (MeBzAm) by N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) in quaternary microemulsions of tetradecyltrimethylammonium bromide (TTABr)/isooctane/alcohol/water, varying the nature and the concentration of the following alcohols: 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol and 1-decanol keeping the [1-alcohol]/[TTABr] = 4 relationship constant. In addition a study was carried out on the influence of the alcohol concentration, working with molar relationships [1-hexanol]/[TTABr]=3, 4 and 5. On the basis of the molar volumes of the alcohol and surfactant and the concentration of alcohol at the interface it was possible to calculate the change in its volume with as varying compositions of the microemulsion. In order to interpret the experimental results a kinetic model was devised which takes into account the distribution of the reactants between the different pseudophases and the change in the volume of the interface. The rate constants at the interface of the microemulsion are lower than in pure water and are independent of the nature of the alcohol used as a cosurfactant and the molar relationship [alcohol]/[TTABr]. This independence indicates that the main role of the cosurfactant is to increase the volume of the interface with the consequent dilution of the reactants.

Alcohols are inhibitors of Saccharomyces cerevisiae multidrug-resistance pumps Pdr5p and Snq2p.

Science.gov (United States)

Gášková, Dana; Plášek, Jaromír; Zahumenský, Jakub; Benešová, Ivana; Buriánková, Luboslava; Sigler, Karel

2013-12-01

The effect of alcohols on cell membrane proteins has originally been assumed to be mediated by their primary action on membrane lipid matrix. Many studies carried out later on both animal and yeast cells have revealed that ethanol and other alcohols inhibit the functions of various membrane channels, receptors and solute transport proteins, and a direct interaction of alcohols with these membrane proteins has been proposed. Using our fluorescence diS-C3 (3) diagnostic assay for multidrug-resistance pump inhibitors in a set of isogenic yeast Pdr5p and Snq2p mutants, we found that n-alcohols (from ethanol to hexanol) variously affect the activity of both pumps. Beginning with propanol, these alcohols have an inhibitory effect that increases with increasing length of the alcohol acyl chain. While ethanol does not exert any inhibitory effect at any of the concentration used (up to 3%), hexanol exerts a strong inhibition at 0.1%. The alcohol-induced inhibition of MDR pumps was detected even in cells whose membrane functional and structural integrity were not compromised. This supports a notion that the inhibitory action does not necessarily involve only changes in the lipid matrix of the membrane but may entail a direct interaction of the alcohols with the pump proteins. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Colin, P

1961-01-04

The addition of C/sub 6-10/ alcohols to the fermenting sugar solutions, increased the yield of alcohol by 1.5 to 5%. The best additives were (additive, % additive in sugar solution, % increased in yield of alcohol): hexanol, 0.03, 2.5; heptanol, 0.05, 3; nonanol, 0.01, 3; 2-ethylbutanol, 0.05, 4; 2-ethylhexanol, 0.05, 5; a mixture of C/sub 7-9/ alcohols from the Oxo synthesis, 0.05, 4.5, and a mixture of C/sub 10/ alcohols 0.05, 3.

Bio-electrochemical synthesis of commodity chemicals by autotrophic acetogens utilizing CO2 for environmental remediation.

Science.gov (United States)

Jabeen, Gugan; Farooq, Robina

2016-09-01

Bio-electrochemical synthesis (BES) is a technique in which electro-autotrophic bacteria such as Clostridium ljungdahlii utilize electric currents as an electron source from the cathode to reduce CO2 to extracellular, multicarbon, exquisite products through autotrophic conversion. The BES of volatile fatty acids and alcohols directly from CO2 is a sustainable alternative for non-renewable, petroleum-based polymer production. This conversion of CO2 implies reduction of greenhouse gas emissions. The synthesis of heptanoic acid, heptanol, hexanoic acid and hexanol, for the first time, by Clostridium ljungdahlii was a remarkable achievement of BES. In our study, these microorganisms were cultivated on the cathode of a bio-electrochemical cell at -400 mV by a DC power supply at 37 degree Centrigrade, pH 6.8, and was studied for both batch and continuous systems. Pre-enrichment of bio-cathode enhanced the electroactivity of cells and resulted in maximizing extracellular products in less time. The main aim of the research was to investigate the impact of low-cost substrate CO2, and the longer cathode recovery range was due to bacterial reduction of CO2 to multicarbon chemical commodities with electrons driven from the cathode. Reactor design was simplified for cost-effectiveness and to enhance energy efficiencies. The Columbic recovery of ethanoic acid, ethanol, ethyl butyrate, hexanoic acid, heptanoic acid and hexanol being in excess of 80 percent proved that BES was a remarkable technology.

Identification and quantification of glue-like off-odors in elastic therapeutic tapes.

Science.gov (United States)

Denk, Philipp; Buettner, Andrea

2018-05-01

Elastic therapeutic tapes are an important tool in the field of physical therapy and medicine. These tapes contain types of adhesive. However, sensory evaluations revealed the release of pronounced and irritating odors of the tapes. Negative odors were, amongst others, reported in elastic therapeutic tapes containing acrylic adhesives. In this study, the odor of four different tape samples was evaluated applying a descriptive analysis approach carried out by a trained sensory panel. Afterwards, the volatile compounds were recovered from the samples by solvent extraction and isolated by solvent-assisted flavor evaporation (SAFE). The obtained distillates were subsequently analyzed by gas chromatography-olfactometry (GC-O) and two-dimensional GC-O coupled with mass spectrometry (2D-GC-MS/O). To determine the most potent odorants in the distillates, odor extract dilution analyses (OEDA) were carried out. Thirty-one odorants were successfully identified using this approach, which were all described for the first time as odorants in tapes. Amongst the set of volatiles, unsaturated and saturated aldehydes were present, eliciting fatty, soapy, and citrus-like odor impressions, as well as a range of glue-like, moldy, and fruity smelling odor-active volatiles, such as 2-ethyl-1-hexanol, butyl benzoate, and 3-phenyltoluene. Based on their relative intensities, the concentrations of the glue-like smelling substances were determined: 2-ethyl-1-hexanol, present in all samples, was determined with concentrations ranging from 10 to 200 mg/kg in the investigated tapes.

Development of An Impedimetric Aptasensor for the Detection of Staphylococcus aureus.

Science.gov (United States)

Reich, Peggy; Stoltenburg, Regina; Strehlitz, Beate; Frense, Dieter; Beckmann, Dieter

2017-11-21

In combination with electrochemical impedance spectroscopy, aptamer-based biosensors are a powerful tool for fast analytical devices. Herein, we present an impedimetric aptasensor for the detection of the human pathogen Staphylococcus aureus . The used aptamer targets protein A, a surface bound virulence factor of S. aureus . The thiol-modified protein A-binding aptamer was co-immobilized with 6-mercapto-1-hexanol onto gold electrodes by self-assembly. Optimization of the ratio of aptamer to 6-mercapto-1-hexanol resulted in an average density of 1.01 ± 0.44 × 10 13 aptamer molecules per cm². As shown with quartz crystal microbalance experiments, the immobilized aptamer retained its functionality to bind recombinant protein A. Our impedimetric biosensor is based on the principle that binding of target molecules to the immobilized aptamer decreases the electron transfer between electrode and ferri-/ferrocyanide in solution, which is measured as an increase of impedance. Microscale thermophoresis measurements showed that addition of the redox probe ferri-/ferrocyanide has no influence on the binding of aptamer and its target. We demonstrated that upon incubation with various concentrations of S. aureus , the charge-transfer resistance increased proportionally. The developed biosensor showed a limit of detection of 10 CFU·mL -1 and results were available within 10 minutes. The biosensor is highly selective, distinguishing non-target bacteria such as Escherichia coli and Staphylococcus epidermidis . This work highlights the immense potential of impedimetric aptasensors for future biosensing applications.

Development of An Impedimetric Aptasensor for the Detection of Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Peggy Reich

2017-11-01

Full Text Available In combination with electrochemical impedance spectroscopy, aptamer-based biosensors are a powerful tool for fast analytical devices. Herein, we present an impedimetric aptasensor for the detection of the human pathogen Staphylococcus aureus. The used aptamer targets protein A, a surface bound virulence factor of S. aureus. The thiol-modified protein A-binding aptamer was co-immobilized with 6-mercapto-1-hexanol onto gold electrodes by self-assembly. Optimization of the ratio of aptamer to 6-mercapto-1-hexanol resulted in an average density of 1.01 ± 0.44 × 1013 aptamer molecules per cm2. As shown with quartz crystal microbalance experiments, the immobilized aptamer retained its functionality to bind recombinant protein A. Our impedimetric biosensor is based on the principle that binding of target molecules to the immobilized aptamer decreases the electron transfer between electrode and ferri-/ferrocyanide in solution, which is measured as an increase of impedance. Microscale thermophoresis measurements showed that addition of the redox probe ferri-/ferrocyanide has no influence on the binding of aptamer and its target. We demonstrated that upon incubation with various concentrations of S. aureus, the charge-transfer resistance increased proportionally. The developed biosensor showed a limit of detection of 10 CFU·mL−1 and results were available within 10 minutes. The biosensor is highly selective, distinguishing non-target bacteria such as Escherichia coli and Staphylococcus epidermidis. This work highlights the immense potential of impedimetric aptasensors for future biosensing applications.

[Analysis of essential oil extracted from Lactuca sativa seeds growing in Xinjiang by GC-MS].

Science.gov (United States)

Xu, Fang; Wang, Qiang; Haji, Akber Aisa

2011-12-01

To analyze the components of essential oil from Lactuca sativa seeds growing in Xinjiang. The components of essential oil from Lactuca sativa seeds were analyzed by gas chromatography-mass spectrometry (GC-MS). 62 components were identified from 71 separated peaks,amounting to total mass fraction 95.07%. The dominant compounds were n-Hexanol (36.31%), n-Hexanal (13.71%), trans-2-Octen-l-ol (8.09%) and 2-n-Pentylfuran (4.41%). The research provides a theoretical basis for the exploitation and use of Lactuca sativa seeds resource.

77 FR 20721 - 2-Ethyl-1-hexanol; Exemption From the Requirement of a Tolerance

Science.gov (United States)

2012-04-06

...-occupational, non-dietary exposure (e.g., textiles (clothing and diapers), carpets, swimming pools, and hard... Executive Order 13211, entitled ``Actions Concerning Regulations That Significantly Affect Energy Supply...

A newly isolated Pseudomonas putida S-1 strain for batch-mode-propanethiol degradation and continuous treatment of propanethiol-containing waste gas

Energy Technology Data Exchange (ETDEWEB)

Chen, Dong-Zhi, E-mail: cdz@zjut.edu.cn [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Sun, Yi-Ming; Han, Li-Mei [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Chen, Jing [College of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316004 (China); Ye, Jie-Xu; Chen, Jian-Meng [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

2016-01-25

Highlights: • A novel strain capable of effectively degrading 1-propanethiol (PT) was isolated. • Cells could be feasibly cultured in nutrition-rich media for PT degradation. • A possible pathway for PT degradation was proposed. • Pseudomonas putida S-1 could degrade mixed pollutants with diauxic growth. • Continuous removal of gaseous PT with or without isopropanol was demonstrated. - Abstract: Pseudomonas putida S-1 was isolated from activated sludge. This novel strain was capable of degrading malodorous 1-propanethiol (PT). PT degradation commenced with no lag phase by cells pre-grown in nutrition-rich media, such as Luria–Bertani (LB), and PT-contained mineral medium at specific growth rates of 0.10–0.19 h{sup −1}; this phenomenon indicated the operability of a large-scale cell culture. A possible PT degradation pathway was proposed on the basis of the detected metabolites, including dipropyl disulfide, 3-hexanone, 2-hexanone, 3-hexanol, 2-hexanol, S{sup 0}, SO{sub 4}{sup 2−}, and CO{sub 2}. P. putida S-1 could degrade mixed pollutants containing PT, diethyl disulfide, isopropyl alcohol, and acetaldehyde, and LB-pre-cultured cells underwent diauxic growth. Waste gas contaminated with 200–400 mg/m{sup 3} PT was continuously treated by P. putida S-1 pre-cultured in LB medium in a completely stirred tank reactor. The removal efficiencies exceeded 88% when PT stream was mixed with 200 mg/m{sup 3} isopropanol; by contrast, the removal efficiencies decreased to 60% as the empty bed residence time was shortened from 40 s to 20 s.

Characterization of the key aroma compounds in pink guava (Psidium guajava L.) by means of aroma re-engineering experiments and omission tests.

Science.gov (United States)

Steinhaus, Martin; Sinuco, Diana; Polster, Johannes; Osorio, Coralia; Schieberle, Peter

2009-04-08

Seventeen aroma-active volatiles, previously identified with high flavor dilution factors in fresh, pink Colombian guavas (Psidium guajava L.), were quantified by stable isotope dilution assays. On the basis of the quantitative data and odor thresholds in water, odor activity values (OAV; ratio of concentration to odor threshold) were calculated. High OAVs were determined for the green, grassy smelling (Z)-3-hexenal and the grapefruit-like smelling 3-sulfanyl-1-hexanol followed by 3-sulfanylhexyl acetate (black currant-like), hexanal (green, grassy), ethyl butanoate (fruity), acetaldehyde (fresh, pungent), trans-4,5-epoxy-(E)-2-decenal (metallic), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel, sweet), cinnamyl alcohol (floral), methyl (2S,3S)-2-hydroxy-3-methylpentanoate (fruity), cinnamyl acetate (floral), methional (cooked potato-like), and 3-hydroxy-4,5-dimethyl-2(5H)-furanone (seasoning-like). Studies on the time course of odorant formation in guava puree or cubes, respectively, showed that (Z)-3-hexenal was hardly present in the intact fruits, but was formed very quickly during crushing. The aroma of fresh guava fruit cubes, which showed a very balanced aroma profile, was successfully mimicked in a reconstitute consisting of 13 odorants in their naturally occurring concentrations. Omission tests, in which single odorants were omitted from the entire aroma reconstitute, revealed (Z)-3-hexenal, 3-sulfanyl-1-hexanol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-sulfanylhexyl acetate, hexanal, ethyl butanoate, cinnamyl acetate, and methional as the key aroma compounds of pink guavas.

Inhibition of MMPs by alcohols

Science.gov (United States)

Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Hoshika, Tomohiro; Uchiyama, Toshikazu; Tjäderhane, Leo; Breschi, Lorenzo; Mazzoni, Annalisa; Thompson, Jeremy M.; McCracken, Courtney E.; Looney, Stephen W.; Tay, Franklin R.; Pashley, David H.

2011-01-01

Objectives While screening the activity of potential inhibitors of matrix metalloproteinases (MMPs), due to the limited water solubility of some of the compounds, they had to be solubilized in ethanol. When ethanol solvent controls were run, they were found to partially inhibit MMPs. Thus, the purpose of this study was to compare the MMP-inhibitory activity of a series of alcohols. Methods The possible inhibitory activity of a series of alcohols was measured against soluble rhMMP-9 and insoluble matrix-bound endogenous MMPs of dentin in completely demineralized dentin. Increasing concentrations (0.17, 0.86, 1.71 and 4.28 moles/L) of a homologous series of alcohols (i.e. methanol, ethanol, propanols, butanols, pentanols, hexanols, the ethanol ester of methacrylic acid, heptanols and octanol) were compared to ethanediol, and propanediol by regression analysis to calculate the molar concentration required to inhibit MMPs by 50% (i.e. the IC50). Results Using two different MMP models, alcohols were shown to inhibit rhMMP-9 and the endogenous proteases of dentin matrix in a dose-dependent manner. The degree of MMP inhibition by alcohols increased with chain length up to 4 methylene groups. Based on the molar concentration required to inhibit rhMMP-9 fifty percent, 2-hydroxyethylmethacrylate (HEMA), 3-hexanol, 3-heptanol and 1-octanol gave the strongest inhibition. Significance The results indicate that alcohols with 4 methylene groups inhibit MMPs more effectively than methanol or ethanol. MMP inhibition was inversely related to the Hoy's solubility parameter for hydrogen bonding forces of the alcohols (i.e. to their hydrophilicity). PMID:21676453

Analysis of volatile organic compounds of ‘Fuji’ apples following electron beam irradiation and storage

International Nuclear Information System (INIS)

Song, Hyun-Pa; Shim, Sung-Lye; Lee, Sun-Im; Kim, Dong-Ho; Kwon, Joong-Ho; Kim, Kyong-Su

2012-01-01

The volatile organic compounds of non-irradiated and electron-beam irradiated ‘Fuji’ apples (Malus domestica Borkh.) at 0, 0.5, and 1 kGy were isolated through simultaneous distillation extractions and analyzed using gas chromatograph–mass spectrometry. A total of 53 volatile organic compounds were characterized in 0 and 1 kGy irradiated samples, whereas two more compounds related to ketone and terpenoid group were identified in 0.5 kGy irradiated samples. The contents of volatile compounds were 24.33, 36.49, and 35.28 mg/kg in 0, 0.5, and 1 kGy irradiated samples, respectively. The major compounds identified were butanol, hexanal, [E]-2-hexenal, and hexanol in all samples. The relative content of alcohol increased after 30 days of storage in all samples, whereas that of aldehyde decreased. Although the contents of some volatile compounds were changed by electron-beam irradiation, the total yield and major flavor compounds of irradiated ‘Fuji’ apples were similar to, or even greater than, those of the control. Therefore, the application of e-beam irradiation if required for microbial decontamination of ‘Fuji’ apples is an acceptable method as it does not bring about any major quantitative changes of volatile organic compounds. - Highlights: ► We analyzed the volatile organic compounds of electron beam irradiated Fuji apples. ► The major compounds of samples were butanol, hexanal, [E]-2-hexenal, and hexanol. ► The contents of major flavor compounds of non-irradiated and irradiated samples were similar.

A newly isolated Pseudomonas putida S-1 strain for batch-mode-propanethiol degradation and continuous treatment of propanethiol-containing waste gas

International Nuclear Information System (INIS)

Chen, Dong-Zhi; Sun, Yi-Ming; Han, Li-Mei; Chen, Jing; Ye, Jie-Xu; Chen, Jian-Meng

2016-01-01

Highlights: • A novel strain capable of effectively degrading 1-propanethiol (PT) was isolated. • Cells could be feasibly cultured in nutrition-rich media for PT degradation. • A possible pathway for PT degradation was proposed. • Pseudomonas putida S-1 could degrade mixed pollutants with diauxic growth. • Continuous removal of gaseous PT with or without isopropanol was demonstrated. - Abstract: Pseudomonas putida S-1 was isolated from activated sludge. This novel strain was capable of degrading malodorous 1-propanethiol (PT). PT degradation commenced with no lag phase by cells pre-grown in nutrition-rich media, such as Luria–Bertani (LB), and PT-contained mineral medium at specific growth rates of 0.10–0.19 h"−"1; this phenomenon indicated the operability of a large-scale cell culture. A possible PT degradation pathway was proposed on the basis of the detected metabolites, including dipropyl disulfide, 3-hexanone, 2-hexanone, 3-hexanol, 2-hexanol, S"0, SO_4"2"−, and CO_2. P. putida S-1 could degrade mixed pollutants containing PT, diethyl disulfide, isopropyl alcohol, and acetaldehyde, and LB-pre-cultured cells underwent diauxic growth. Waste gas contaminated with 200–400 mg/m"3 PT was continuously treated by P. putida S-1 pre-cultured in LB medium in a completely stirred tank reactor. The removal efficiencies exceeded 88% when PT stream was mixed with 200 mg/m"3 isopropanol; by contrast, the removal efficiencies decreased to 60% as the empty bed residence time was shortened from 40 s to 20 s.

Characterization of surfactant liquid crystal phases suitable for molecular alignment and measurement of dipolar couplings

International Nuclear Information System (INIS)

Barrientos, Laura G.; Dolan, Caroline; Gronenborn, Angela M.

2000-01-01

Media employed for imparting partial alignment onto solute molecules have recently attracted considerable attention, since they permit the measurement of NMR parameters for solute biomolecules commonly associated with solid state NMR. Here we characterize a medium which is based on a quasi-ternary surfactant system comprising cetylpyridinium bromide/hexanol/sodium bromide. We demonstrate that dilute solutions of this system can exist in liquid crystalline phases which orient in the magnetic field and allow the measurement of residual dipolar couplings under a variety of conditions. The present system is extremely versatile and robust, tolerating different buffer conditions, temperature ranges and concentrations

Characteristic Flavor of Traditional Soup Made by Stewing Chinese Yellow-Feather Chickens.

Science.gov (United States)

Qi, Jun; Liu, Deng-Yong; Zhou, Guang-Hong; Xu, Xing-Lian

2017-09-01

The traditional recipe for Chinese chicken soup creates a popular taste of particular umami and aroma. The present study investigated the effects of stewing time (1, 2, and 3 h) on the principal taste-active and volatile compounds and the overall flavor profile of traditional Chinese chicken soup by measuring the contents of free amino acids (FAAs), 5'-nucleotides, minerals and volatile compounds and by evaluating the taste and aroma profiles using an electronic nose, an electronic tongue and a human panel. Results showed that the major umami-related compounds in the chicken soup were inosine 5'-monophosphate (IMP) and chloride, both of which increased significantly (P < 0.05) during stewing. The taste active values (TAVs) of the equivalent umami concentration (EUC) increased from 4.08 to 9.93 (P < 0.05) after stewing for 3 h. Although the FAA and mineral contents increased significantly (P < 0.05), their TAVs were less than 1. The volatile compounds were mainly hexanal, heptanal, octanal, nonanal, (E)-2-nonanal, (E)-2-decenal, (E,E)-2,4-decadienal, 1-hexanol, and 2-pentyl furan. With the prolonged stewing time, the aldehydes first increased and then decreased significantly (P < 0.05), while 1-hexanol and 2-pentyl furan increased steadily (P < 0.05). The aroma scores of the chicken soup reached the maximum after stewing for 3 h. The discrepancy in overall flavor characteristics tended to stabilize after 2 h of stewing. In general, stewing time has a positive effect on improving the flavor profiles of chicken soup, especially within the first 2 h. © 2017 Institute of Food Technologists®.

The Role of Leaf Volatiles of Ludwigia octovalvis (Jacq.) Raven in the Attraction of Altica cyanea (Weber) (Coleoptera: Chrysomelidae).

Science.gov (United States)

Mitra, Saubhik; Karmakar, Amarnath; Mukherjee, Abhishek; Barik, Anandamay

2017-07-01

Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae. In contrast, feeding by adults caused the release of 2Z-penten-1-ol only after 12 and 36 h; whereas geraniol and 1-tridecanol appeared only after 36 h. Farnesyl acetone was detected after 12 and 36 h of feeding by larvae and after 36 h of feeding by adults. Farnesene was detected after 36 h of feeding by larvae and adults. Linalool was unique after 36 h of feeding by larvae. In Y-shaped glass tube olfactometer bioassays, A. cyanea females were attracted to volatiles after 36 h of feeding by larvae or adults compared to volatiles released by undamaged plants. The insects were attracted to five synthetic compounds: 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. Synthetic blends were more attractive than individual compounds. Compared to undamaged plants, volatiles released by plants, damaged by conspecific individuals, were more attractive to A. cyanea females, due to elevated emissions of 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol.

Carbon dioxide conversion to fuels and chemicals using a hybrid green process

International Nuclear Information System (INIS)

Ramachandriya, Karthikeyan D.; Kundiyana, Dimple K.; Wilkins, Mark R.; Terrill, Jennine B.; Atiyeh, Hasan K.; Huhnke, Raymond L.

2013-01-01

Highlights: • A unique CO 2 conversion technology using microorganisms was demonstrated. • Corn steep liquor medium enhanced production of n-butanol and n-hexanol. • Cotton seed extract (CSE) medium promoted ethanol formation. • CSE medium without morpholinoethanesulfonic acid buffer reduced the cost by 99%. - Abstract: A unique hybrid technology that uses renewable hydrogen (H 2 ) and carbon dioxide (CO 2 ) sequestered from large point sources, to produce fuels and chemicals has been proposed and tested. The primary objective of this research was to determine the feasibility of using two acetogenic bacteria to metabolize H 2 and CO 2 for the production of ethanol. Three experiments were conducted in small scale reactors to select a bacterium, feed gas composition and nutrient medium source to produce ethanol. The results indicated that Clostridium carboxidivorans produced 33% more ethanol and 66% less acetic acid compared to Clostridium ragsdalei, making C. carboxidivorans the better candidate for ethanol production. Furthermore, the removal of morpholinoethanesulfonic acid (MES) buffer from cotton seed extract (CSE) medium offered a low-cost medium for fermentations. Additionally, we observed that corn steep liquor (CSL) in the medium diversified the product range with both bacteria. Maximum concentrations of ethanol, n-butanol, n-hexanol, acetic acid, butyric acid, and hexanoic acid from different fermentation treatments were 2.78 g L −1 , 0.70 g L −1 , 0.52 g L −1 , 4.06 g L −1 , 0.13 g L −1 and 0.42 g L −1 , respectively. This study highlights the important role that acetogenic microbes can offer for CO 2 conversion into valuable fuels and chemicals

Dielectric studies on binary mixtures of Tri-n-butyl phosphate (TBP) and long-chain primary alcohols (modifiers)

International Nuclear Information System (INIS)

Dash, S.K.; Swain, B.B.

1993-01-01

Dielectric constant (ε) of Tri-n-butyl phosphate (TBP), in binary mixtures with five long-chain primary alcohols viz; 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol has been measured at ν = 455 kHz and at temperature 302 K. The data is used to evaluate mutual correlation factor g ab , excess molar polarization ΔP and excess free energy of mixing ΔF ab by using Winkelmann-Quitzsch eqn. for binary mixtures to assess the suitability of the alcohols as modifiers. The trend of variation of these parameters exhibit marked dependence on chain-length of the alcohols indicating 1-heptanol to be an efficient modifier. (author)

Enzymatic Continuous Flow Synthesis of Thiol-Terminated Poly(δ-Valerolactone) and Block Copolymers.

Science.gov (United States)

Zhu, Ning; Huang, Weijun; Hu, Xin; Liu, Yihuan; Fang, Zheng; Guo, Kai

2018-04-01

Thiol-terminated poly(δ-valerolactone) is directly synthesized via enzymatic 6-mercapto-1-hexanol initiated ring-opening polymerization in both batch and microreactor. By using Candida antartica Lipase B immobilized tubular reactor, narrowly dispersed poly(δ-valerolactone) with higher thiol fidelity is more efficiently prepared in contrast to the batch reactor. Moreover, the integrated enzyme packed tubular reactor system is established to perform the chain extension experiments. Thiol-terminated poly(δ-valerolactone)-block-poly(ε-caprolactone) and poly(ε-caprolactone)-block-poly(δ-valerolactone) are easily prepared by modulating the monomer introduction sequence. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemo- and regioselective homogeneous rhodium-catalyzed hydroamidomethylation of terminal alkenes to N-alkylamides.

Science.gov (United States)

Raoufmoghaddam, Saeed; Drent, Eite; Bouwman, Elisabeth

2013-09-01

A rhodium/xantphos homogeneous catalyst system has been developed for direct chemo- and regioselective mono-N-alkylation of primary amides with 1-alkenes and syngas through catalytic hydroamidomethylation with 1-pentene and acetamide as model substrates. For appropriate catalyst performance, it appears to be essential that catalytic amounts of a strong acid promoter, such as p-toluenesulfonic acid (HOTs), as well as larger amounts of a weakly acidic protic promoter, particularly hexafluoroisopropyl alcohol (HOR(F) ) are applied. Apart from the product N-1-hexylacetamide, the isomeric unsaturated intermediates, hexanol and higher mass byproducts, as well as the corresponding isomeric branched products, can be formed. Under optimized conditions, almost full alkene conversion can be achieved with more than 80% selectivity to the product N-1-hexylamide. Interestingly, in the presence of a relatively high concentration of HOR(F) , the same catalyst system shows a remarkably high selectivity for the formation of hexanol from 1-pentene with syngas, thus presenting a unique example of a selective rhodium-catalyzed hydroformylation-hydrogenation tandem reaction under mild conditions. Time-dependent product formation during hydroamidomethylation batch experiments provides evidence for aldehyde and unsaturated intermediates; this clearly indicates the three-step hydroformylation/condensation/hydrogenation reaction sequence that takes place in hydroamidomethylation. One likely role of the weakly acidic protic promoter, HOR(F) , in combination with the strong acid HOTs, is to establish a dual-functionality rhodium catalyst system comprised of a neutral rhodium(I) hydroformylation catalyst species and a cationic rhodium(III) complex capable of selectively reducing the imide and/or ene-amide intermediates that are in a dynamic, acid-catalyzed condensation equilibrium with the aldehyde and amide in a syngas environment. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of the synergistic effect of alcoholic compounds on the extraction of H3PO4 from Syrian wet phosphoric acid by TBP

International Nuclear Information System (INIS)

Abdulbaki, M. K.; Shino, O.; Wahoud, A.

2006-01-01

This paper studies the synergistic effects of alcoholic compounds such as isoamyl alcohol. Pentanol, hexanol and heptanol on the extraction of H 3 PO 4 from Syrian phosphoric acid by (TBP). The possibility to use these alcoholic compounds as a diluent instead of kerosene was also studied. The results show that the alcoholic compounds has bigger extraction yield than (TBP) diluted in kerosene. The alcoholic compounds has an important synergistic effect, when it was used as a diluent instead of kerosene, on the extraction of H 3 PO 4 by (TBP) and they have a bigger extraction yield and the quicker phase separation comparing with kerosene. Extraction of uranium, fluoride, sulfate and heavy metals is relatively small. (Authors)

Densities, excess molar volumes, and refractive indices of 1,1,2,2-tetrabromoethane and 1-alkanols binary mixtures

International Nuclear Information System (INIS)

Al-Hayan, M.N.M.; Al-Bader, Maher A.M.

2006-01-01

Densities, excess molar volumes, refractive indices, and changes in refractive index on mixing for (1,1,2,2-tetrabromoethane + 1-pentanol, or 1-hexanol, or 1-heptanol, or 1-octanol, or 1-decanol) have been determined at T = 293.15 K and at T = 303.15 K. The excess molar volumes and changes in refractive index have been fitted to Redlich-Kister polynomials. The effect of the chain length of the 1-alkanol on the excess molar volume and the change in the refractive index of its mixtures with 1,1,2,2-tetrabromoethane are discussed. In addition, the refractive indices are compared with calculated values using mixing rules proposed by several authors, and a good agreement is obtained

Densities, excess molar volumes, and refractive indices of 1,1,2,2-tetrachloroethane and 1-alkanols binary mixtures

International Nuclear Information System (INIS)

Al-Hayan, M.N.M.

2006-01-01

Densities, excess molar volumes, refractive indices, and changes in refractive index on mixing for 1,1,2,2-tetrachloroethane + 1-pentanol, or 1-hexanol, or 1-heptanol, or 1-octanol, or 1-decanol have been determined at T = (293.15 and 303.15) K. The excess molar volumes and changes in refractive index have been fitted to Redlich-Kister polynomials. The effect of the chain length of the 1-alkanol on the excess molar volume and the change in the refractive index of its mixtures with 1,1,2,2-tetrachloroethane was discussed. In addition, the refractive indices were compared with calculated values using mixing rules proposed by several authors, and a very good agreement was obtained

Analysis of volatile components of cape gooseberry (Physalis peruviana L.) grown in Turkey by HS-SPME and GC-MS.

Science.gov (United States)

Yilmaztekin, Murat

2014-01-01

Volatile components in cape gooseberry fruit at ripe stage were collected using headspace-solid phase microextraction, and analyzed by gas chromatography-mass spectrometry. Three solid phase microextraction fiber coatings (DVB/CAR/PDMS, CAR/PDMS, and PDMS/DVB) were tested for evaluation of volatile compounds. DVB/CAR/PDMS fiber showed a strong extraction capacity for volatile compounds and produced the best result in case of total peak areas. A total of 133 volatile compounds were identified in fruit pulp; among them 1-hexanol (6.86%), eucalyptol (6.66%), ethyl butanoate (6.47%), ethyl octanoate (4.01%), ethyl decanoate (3.39%), 4-terpineol (3.27%), and 2-methyl-1-butanol (3.10%) were the major components in the sample extracts.

Analysis of Volatile Components of Cape Gooseberry (Physalis peruviana L. Grown in Turkey by HS-SPME and GC-MS

Directory of Open Access Journals (Sweden)

Murat Yilmaztekin

2014-01-01

Full Text Available Volatile components in cape gooseberry fruit at ripe stage were collected using headspace-solid phase microextraction, and analyzed by gas chromatography-mass spectrometry. Three solid phase microextraction fiber coatings (DVB/CAR/PDMS, CAR/PDMS, and PDMS/DVB were tested for evaluation of volatile compounds. DVB/CAR/PDMS fiber showed a strong extraction capacity for volatile compounds and produced the best result in case of total peak areas. A total of 133 volatile compounds were identified in fruit pulp; among them 1-hexanol (6.86%, eucalyptol (6.66%, ethyl butanoate (6.47%, ethyl octanoate (4.01%, ethyl decanoate (3.39%, 4-terpineol (3.27%, and 2-methyl-1-butanol (3.10% were the major components in the sample extracts.

One-pot reduction of 5-hydroxymethylfurfural via hydrogen transfer from supercritical methanol

DEFF Research Database (Denmark)

Hansen, Thomas Søndergaard; Barta, Katalin; Anastas, Paul T.

2012-01-01

Catalytic conversion of HMF to valuable chemicals was achieved over a Cu-doped porous metal oxide in supercritical methanol. The hydrotalcite catalyst precursor is prepared following simple synthetic procedures, using inexpensive and earth-abundant starting materials in aqueous solutions. The hyd......Catalytic conversion of HMF to valuable chemicals was achieved over a Cu-doped porous metal oxide in supercritical methanol. The hydrotalcite catalyst precursor is prepared following simple synthetic procedures, using inexpensive and earth-abundant starting materials in aqueous solutions....... The hydrogen equivalents needed for the reductive deoxygenation of HMF originate from the solvent itself upon its reforming. Dimethylfuran, dimethyltetrahydrofuran and 2-hexanol were obtained in good yields. At milder reaction temperatures, a combined yield (DMF + DMTHF) of 58% was achieved. Notably...

Lyotropic liquid crystal based on zinc oxide nanoparticles obtained by microwave solvothermal synthesis

Energy Technology Data Exchange (ETDEWEB)

Omelchenko, M.M., E-mail: momelchenko@chem.uw.edu.pl [Department of Chemistry, Warsaw University, Al. Zwirki i Wigury 101, 02-089, Warsaw (Poland); Wojnarowicz, J. [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, Warsaw, 01-142 (Poland); Salamonczyk, M. [Department of Chemistry, Warsaw University, Al. Zwirki i Wigury 101, 02-089, Warsaw (Poland); Lojkowski, W. [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, Warsaw, 01-142 (Poland)

2017-05-01

Abstract: The ZnO nanoparticles, obtained by microwave solvothermal synthesis, were used for the liquid crystal phase preparation. The structure of the material was investigated by X-ray diffraction (XRD), helium pycnometry, specific surface area (SSA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM). The stability of aqueous suspensions was monitored by Multiple Light Scattering (MLS) technique and the average agglomerate size in suspensions was obtained by dynamic light scattering (DLS) technique. The lyotropic columnar hexagonal phase was formed by doping ZnO nanoparticles into the cetylpiridinium chloride/water/hexanol system. The structure of this phase was confirmed by x-ray diffraction. The luminescent properties of the LC phase were compared with properties of ZnO nanoparticles isolated in solution and analogues lyotropic system without nanoparticles.

Effect of microemulsion component purity on the chromatographic figures of merit in chiral microemulsion electrokinetic chromatography.

Science.gov (United States)

Kojtari, Adeline B; Foley, Joe P

2009-04-17

Numerous combinations of one-, two-, and three-chiral-component microemulsions have been previously prepared in our group, using N-dodecoxycarbonylvaline (DDCV), 2-hexanol, and ethyl acetate, dibutyl tartrate, or diethyl tartrate. A few results of the various formulations investigated suggested the possible presence of minor impurities in one or more components of the microemulsion. In this study, the purity of the current lots of R- and S-surfactant were measured, as was the subsequent effect of minor impurities on the relevant chromatographic figures of merit (CFOMs) that describe a chiral separation, i.e., efficiency, enantioselectivity, retention, migration window (elution range), and resolution. Two related methods are proposed for correcting enantioselectivities measured in the presence of chiral impurities in the chiral microemulsion.

Structural and Affinity Determinants in the Interaction between Alcohol Acyltransferase from F. x ananassa and Several Alcohol Substrates: A Computational Study.

Directory of Open Access Journals (Sweden)

Carlos Navarro-Retamal

Full Text Available Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT (EC 2.3.1.84 catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters in fruits and flowers. In Fragaria x ananassa, there are different volatiles compounds that are obtained from different alcohol precursors, where octanol and hexanol are the most abundant during fruit ripening. At present, there is not structural evidence about the mechanism used by the AAT to synthesize esters. Experimental data attribute the kinetic role of this enzyme to 2 amino acidic residues in a highly conserved motif (HXXXD that is located in the middle of the protein. With the aim to understand the molecular and energetic aspects of volatiles compound production from F. x ananassa, we first studied the binding modes of a series of alcohols, and also different acyl-CoA substrates, in a molecular model of alcohol acyltransferase from Fragaria x ananassa (SAAT using molecular docking. Afterwards, the dynamical behavior of both substrates, docked within the SAAT binding site, was studied using routine molecular dynamics (MD simulations. In addition, in order to correlate the experimental and theoretical data obtained in our laboratories, binding free energy calculations were performed; which previous results suggested that octanol, followed by hexanol, presented the best affinity for SAAT. Finally, and concerning the SAAT molecular reaction mechanism, it is suggested from molecular dynamics simulations that the reaction mechanism may proceed through the formation of a ternary complex, in where the Histidine residue at the HXXXD motif deprotonates the alcohol substrates. Then, a nucleophilic attack occurs from alcohol charged oxygen atom to the carbon atom at carbonyl group of the acyl CoA. This

Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols

International Nuclear Information System (INIS)

Jambon, C.

1962-01-01

After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [fr

Synthesis and toxicity test of magnetic nanoparticle via biocompatible microemulsion system as template for application in targeted drug delivery

Science.gov (United States)

Kader, Razinah Abdul; Rose, Laili Che; Suhaimi, Hamdan; Manickam, Mariessa Soosai

2017-09-01

This work reports the preparation of magnetic nanoparticles (FeNPs) using biocompatible W/O microemulsion for biomedical applications. W/O microemulsion was formed using decane as oil phase, water, tween 80 as non-ionic surfactant and hexanol as organic solvent. The synthesized FeNPs were characterised by using Fourier Transform Infrared Resonance Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The FTIR showed that Fe-O bond exist on 581cm-1 having strong magnetic strength whereas SEM showed the morphology surface of magnetic nanoparticles (FeNPs). Furthermore, analysis of XRD pattern magnetic nanoparticles (FeNPs) reveals a cubic iron oxide phase with good crystallize structure. Furthermore, toxicity test on human liver cells proved that it is 70% safe on human and proved to be a safety nanomedicine.

Surfactant Membrane Phases Containing Mixtures of Hydrocarbon and Fluorocarbon Surfactants

International Nuclear Information System (INIS)

de Campo, Liliana; Warr, G.G.

2005-01-01

Full text: We describe the structure and stability of sponge and lamellar phases comprising mixtures of hydrocarbon and fluorocarbon surfactants. Such mixtures can show limited miscibility with each other, forming for example coexisting populations of hydrocarbon rich and fluorocarbon rich micelles under some circumstances. Our system is based on the well-characterised lamellar and sponge phases of cetylpyridinium chloride, hexanol and 0.2M brine, into which the partially fluorinated surfactant N-1H,1H,2H,2H-tridecafluorooctylpyridinium chloride is incorporated. By probing the structures with SAXS (small angle x-ray scattering) and SANS (small angle neutron scattering) using contrast variation, and by characterizing the dynamic properties with dynamic light scattering, we will describe the effect of incorporating the fluorinated surfactant on the phase equilibria and properties of the surfactant membrane structures. (authors)

Injury to crops by gas as produced from plastic materials

Energy Technology Data Exchange (ETDEWEB)

Inden, T; Tachibana, S

1971-01-01

The effects of gas formations of phthalate and epoxy plasticizers on crops were studied at room temperature and 100 to 200 C. The materials were tested either alone Or as products including polyvinyl chloride and a stabilizer. At room temperature, dioctylphthalate (DOP) did not injure the cucumber leaves, whereas diisobutyl phthalate (DIBF) injured 74.1%, and dibutyl phthalate injured 36.5% of the surface of the leaves. Among many stabilizers tested, triphenyl phosphite injured 80% of the surface area of cucumber leaves. At 100 C to 200 C for 48 hours DIBP and CLP injured the Chinese cabbage leaves most, about 80% of the surface area. The following chemicals for the manufacturing of the plasticizers were also found to injure Chinese cabbage leaves, isobutanol 18.3%, 2-ethyl-hexanol 98.3%, isodecanol 98.5%, phthalic acid 40.0, and adipic acid 6.6%.

Diamond-based electrochemical aptasensor realizing a femtomolar detection limit of bisphenol A.

Science.gov (United States)

Ma, Yibo; Liu, Junsong; Li, Hongdong

2017-06-15

In this study, we designed and fabricated an electrochemical impedance aptasensor based on Au nanoparticles (Au-NPs) coated boron-doped diamond (BDD) modified with aptamers, and 6-mercapto-1-hexanol (MCH) for the detection of bisphenol A (BPA). The constructed BPA aptasensor exhibits good linearity from 1.0×10 -14 to 1.0×10 -9 molL -1 . The detection limitation of 7.2×10 -15 molL -1 was achieved, which can be attributed to the synergistic effect of combining BDD with Au-NPs, aptamers, and MCH. The examine results of BPA traces in Tris-HCl buffer and in milk, UV spectra of aptamer/BPA and interference test revealed that the novel aptasensors are of high sensitivity, specificity, stability and repeatability, which could be promising in practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Constituents of essential oil from the dried fruits and stems of Akebia quinata (THUNB.) DECNE.

Science.gov (United States)

Kawata, Jyunichi; Kameda, Munekazu; Miyazawa, Mitsuo

2007-01-01

The compositions of the essential oil from AKEBIAE FRUCTUS and AKEBIAE CAULIS, the dried fruits and stems of Akebia quinata (THUNB.) DECNE. (Lardizabalaceae), have been investigated by GC and GC/MS. As a result, the fruits oil was revealed the presence of 86 components, representing 98.4% of the total oil. The major compounds of the fruits oil were limonene, eugenol, octanal and p-cymene. The monoterpenoids and saturated short-chain aldehyde (C6 approximately C10) were main volatile fractions of the oil. Ninety components accounting for 90.5% of constituents of stems oil were identified, and the main compounds of the oil were hexanoic acid, palmitic acid, (2E, 4E)-decadienal and hexanol. The oil had high content of saturated fatty acids (C6 approximately C16), and unsaturated short-chain aldehyde (C6 approximately C10).

Association of bacteriochlorophyll a with the CsmA protein in chlorosomes of the photosynthetic green filamentous bacterium Chloroflexus aurantiacus

DEFF Research Database (Denmark)

Sakuragi, Y; Frigaard, N-U; Shimada, K

1999-01-01

with molecular masses of 11 and 18 kDa (CsmN and CmsM), whereas the spectral properties of BChl a and BChl c were not changed. By the new hexanol-detergent (HD) treatment, most BChl c and all of the detected proteins except CsmA were removed from the chlorosomes without changing the BChl a spectral properties....... Subsequent proteinase K treatment of these HD-treated chlorosomes caused digestion of CsmA and a simultaneous decrease of the BChl a absorption band. Based on these results, we suggest that CsmA is associated with BChl a in the chlorosomes. This suggestion was supported by the measured stoichiometric ratio...... of BChl a to CsmA in isolated chlorosomes, which was estimated to be between 1.2 and 2.7 by amino acid analysis of the SDS-PAGE-resolved protein bands....

Studies of volatile secondary molasses constituents with inhibitory effect on yeast fermentation. Pt. 1. Determination of molasses and yeast components by GC and HPLC; Untersuchungen ueber fluechtige Nebenbestandteile der Melasse mit inhibitorischer Wirkung auf die Hefegaerung. T. 1. Bestimmung von Melasse- und Hefeinhaltsstoffen mittels GC und HPLC

Energy Technology Data Exchange (ETDEWEB)

Fattohi, N.

1994-07-20

Beet molasses, the principal raw material of molasses distilleries and yeast factories, have in recent times with increasing frequency shown negative effects on the fermentation and quality of baking yeast. Based on the fact that with many ``problem molasses`` the inhibitory effect on fermentation can be substantially reduced and often even totally eliminated by prior aeration of the hot acidic molasses solution, the chemical-analytical and biological investigations presented here focused on the components of such problem molasses volatilizable in water vapour. The water vapour distillates contain, in particular, low carbon acids (C1-C10), and alkanols (C6-C7), the minimum inhibitory concentrations (m.i.c.) of which for yeast fermentation were established. This showed very high m.i.c. levels for an inhibitory effect on fermentation, which in practice are not reached by the individual carbon acid and alkanol constituents of the problem molasses. However, these acids and alcohols exhibit marked synergic effects which were confirmed by determining the m.i.c. values of mixtures. The inhibitory effect on yeast fermentation is due above all to the presence in problem molasses of butyric acid + caprilic acid + hexanol and heptanol. (orig.) [Deutsch] Ruebenmelasse, der Hauptrohstoff fuer die Melassebrennereien und Hefefabriken, zeigt in letzter Zeit immer haeufiger nachteilige Wirkungen bei der Vergaerung sowie der Qualitaet des Produkts Backhefe. Aufgrund der Tatsache, dass sich bei vielen ``Problemmelassen`` der Gaerhemmeffekt durch vorangehende Belueftung der heiss-sauren Melasseloesung deutlich vermindern, haeufig sogar gaenzlich eliminieren laesst, wurde der Schwerpunkt der vorliegenden chemisch-analytischen und biologischen Untersuchungen auf die wasserdampffluechtigen Komponenten solcher Problemmelassen gelegt. Die Wasserdampfdestillate enthalten insbesondere niedere Carbonsaeuren (C1-C10) und Alkanole (C6-C7). Ihre minimalen Hemmkonzentrationen (MHK) bei der

Kinetic study on the enzymatic esterification of octanoic acid and hexanol by immobilized Candida antarctica lipase B

DEFF Research Database (Denmark)

Lopresto, Catia Giovanna; Calabro, Vincenza; Woodley, John M.

2014-01-01

a Ping-Pong bi-bi mechanism with dead-end inhibition by both substrates and, based on the proposed model, the kinetic constants of the esterification reaction are estimated. These parameters are verified to be intrinsic – neither external nor internal mass transfer resistances are significant...

Synthesis and Tribological Studies of Branched Alcohol Derived Epoxidized Biodiesel

Directory of Open Access Journals (Sweden)

Qinggong Ren

2015-09-01

Full Text Available The optimization and kinetics of the ring-opening reaction of an epoxidized biodiesel (epoxidized rapeseed oil methyl ester (EBD with 2-ethyl hexanol (2-EH were studied. The determined optimum conditions were 4:1 2-EH/oil molar ratio, 90 °C, 18 h, and 7 wt % of Amberlyst D001 (dry catalyst; the product’s oxirane oxygen content was 0.081% with 38.32 mm2/s viscosity at 40 °C. The catalyst retained its high catalytic power after recycling five times. Furthermore, the determined non-catalyzed activation energy was 76 kJ·mol−1 and 54 kJ·mol−1 with the D001 resin catalyst. The product’s chemical structure was investigated through FT-IR and 1H NMR. The viscosity, flash point, pour point, and anti-wear properties of the product were improved compared with those of epoxidized biodiesel.

Pedologic Factors Affecting Virgin Olive Oil Quality of "Chemlali" Olive Trees (Olea europaea L.).

Science.gov (United States)

Rached, Mouna Ben; Galaverna, Gianni; Cirlini, Martina; Boujneh, Dalenda; Zarrouk, Mokhtar; Guerfel, Mokhtar

2017-08-01

The aim of this study examined the characterization of extra virgin olive oil samples from the main cultivar Chemlali, grown in five olive orchards with different soil type (Sandy, Clay, Stony, Brown, Limestone and Gypsum). Volatile compounds were studied using headspace-solid phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) technics. Moreover, the sterol profile was established using gas chromatography-mass spectrometry. 35 different volatile compounds were identified: alcohols, esters, aldehydes, ketones and hydrocarbons. The chemical composition of the volatile fraction was characterized by the preeminence of 2-hexenal (32.75%) and 1-hexanol (31.88%). Three sterols were identified and characterized. For all olive oil samples, ß-sitosterol (302.25 mg/kg) was the most abundant sterol. Interestingly, our results showed significant qualitative and quantitative differences in the levels of the volatile compounds and sterols from oils obtained from olive trees grown in different soil type.

Odorant Screening and Quantitation of Thiols in Carmenere Red Wine by Gas Chromatography-Olfactometry and Stable Isotope Dilution Assays.

Science.gov (United States)

Pavez, Carolina; Agosin, Eduardo; Steinhaus, Martin

2016-05-04

The sensory impact of thiols in Vitis vinifera 'Carmenere' red wines was evaluated. For this purpose, aroma extract dilution analysis was applied to the thiols isolated from a Carmenere red wine by affinity chromatography with a mercurated agarose gel. Results revealed the presence of four odorants, identified as 2-furanylmethanethiol, 3-sulfanylhexyl acetate, 3-sulfanyl-1-hexanol, and 2-methyl-3-sulfanyl-1-butanol, with the latter being described here for the first time in Carmenere red wines. Quantitation of the four thiols in the Carmenere wine screened by aroma extract dilution analysis and in three additional Carmenere wines by stable isotope dilution assays resulted in concentrations above the respective orthonasal odor detection threshold values. Triangle tests applied to wine model solutions with and without the addition of the four thiols showed significant differences, thus suggesting that the compounds do have the potential to influence the overall aroma of red wine.

Effect of temperature on the behavior of surface properties of alcohols in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Romero, Carmen M. [Facultad de Ciencias, Universidad Nacional de Colombia, Bogota (Colombia)], E-mail: cmromeroi@unal.edu.co; Jimenez, Eulogio [Facultade de Ciencias, Universidade da Coruna (Spain); Suarez, Felipe [Facultad de Ciencias, Universidad Nacional de Colombia, Bogota (Colombia)

2009-04-15

The influence of temperature on the behavior of surface properties of aqueous solutions has often been used to obtain information about solute structural effects on water. In this work, we present experimental results for surface tension of aqueous solutions of n-pentanol, n-hexanol, n-heptanol, and n-octanol at T = (283.15, 288.15, 293.15, 298.15, 303.15, and 308.15) K at several concentrations. The results were used to evaluate the limiting experimental slopes of surface tension with respect to mole fraction and the hydrophobicity constant of the Connors model at each temperature. The thermodynamic behavior of aqueous alcohol solutions is discussed in terms of the effect of the hydrocarbon chain on water structure. The temperature dependence of the limiting slopes of surface tension with respect to mole fraction, as well as the hydrophobicity constant derived from surface measurements, is interpreted in terms of alcohol hydration.

Selective extraction of palladium with caffeine from acidic chloride media; Sansei enkabutsu yoeki karano kafuein ni yoru parajiumu no sentakuteki chushutsu

Energy Technology Data Exchange (ETDEWEB)

Kaikake, K.; Baba, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

1999-06-10

In order to examine the possibility of caffeine as an extractant, the extraction of metal ions from acidic chloride media was studied at 298 K using the mixture solvent of chloroform and 2-ethyl-1-hexanol. Caffeine has exhibited a high selectivity for palladium (2) over base metals such as copper (2), nickel (2), and iron (3), and over precious metal such as platinum (4). The stoichiometric relation in the extraction of palladium (2) with caffeine was elucidated by examining the effects of chloride ion, hydrogen ion, and caffeine concentrations on its extractability. In addition, palladium (2) was found to be extracted selectively with caffeine from the mixture containing a 25-fold amount of platinum (4) or copper (2). The stripping of palladium (2) was performed to an extent of 80% by a single batchwise treatment with an aqueous mixture solution of hydrochloric acid and thiourea. (author)

Effect of temperature on the behavior of surface properties of alcohols in aqueous solution

International Nuclear Information System (INIS)

Romero, Carmen M.; Jimenez, Eulogio; Suarez, Felipe

2009-01-01

The influence of temperature on the behavior of surface properties of aqueous solutions has often been used to obtain information about solute structural effects on water. In this work, we present experimental results for surface tension of aqueous solutions of n-pentanol, n-hexanol, n-heptanol, and n-octanol at T = (283.15, 288.15, 293.15, 298.15, 303.15, and 308.15) K at several concentrations. The results were used to evaluate the limiting experimental slopes of surface tension with respect to mole fraction and the hydrophobicity constant of the Connors model at each temperature. The thermodynamic behavior of aqueous alcohol solutions is discussed in terms of the effect of the hydrocarbon chain on water structure. The temperature dependence of the limiting slopes of surface tension with respect to mole fraction, as well as the hydrophobicity constant derived from surface measurements, is interpreted in terms of alcohol hydration

Pre-fermentation addition of grape tannin increases the varietal thiols content in wine.

Science.gov (United States)

Larcher, Roberto; Tonidandel, Loris; Román Villegas, Tomás; Nardin, Tiziana; Fedrizzi, Bruno; Nicolini, Giorgio

2015-01-01

The recent finding that grape tannin may contain significant amount of S-glutathionylated (GSH-3MH) and S-cysteinylated (Cys-3MH) precursors of the varietal thiols 3-mercapto-1-hexanol and 3-mercaptohexyl acetate, characteristic of Sauvignon blanc wines, offers new opportunities for enhancing the tropical aroma in fermented beverages. In this study this new hypothesis was investigated: Müller Thurgau (17 samples) and Sauvignon blanc (15 samples) grapes were fermented with and without addition of a selected grape tannin. As expected, the tannin-added juices were higher in precursors, and they produced wines with increased free thiols. Preliminary informal sensory tests confirmed that in particular the Sauvignon wines produced with the tannin addition were often richer with increased "fruity/green" notes than the corresponding reference wines. This outcome confirms that grape tannin addition prior to fermentation can fortify the level of these compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

Aroma barrier properties of sodium caseinate-based films.

Science.gov (United States)

Fabra, Maria José; Hambleton, Alicia; Talens, Pau; Debeaufort, Fréderic; Chiralt, Amparo; Voilley, Andrée

2008-05-01

The mass transport of six different aroma compounds (ethyl acetate, ethyl butyrate, ethyl hexanoate, 2-hexanone, 1-hexanol, and cis-3-hexenol) through sodium caseinate-based films with different oleic acid (OA)/beeswax (BW) ratio has been studied. OA is less efficient than BW in reducing aroma permeability, which can be attributed to its greater polarity. Control film (without lipid) and films prepared with 0:100 OA/BW ratio show the lowest permeability. OA involves a decrease in aroma barrier properties of the sodium caseinate-based films due to its plasticization ability. Preferential sorption and diffusion occurs through OA instead of caseinate matrix and/or BW. The efficiency of sodium caseinate-based films to retain or limit aroma compound transfers depend on the affinity of the volatile compound to the films, which relates physicochemical interaction between volatile compound and film. Specific interactions (aroma compound-hydrocolloid and aroma compound-lipid) induce structural changes during mass transfer.

Temperature-dependent self-assembly and rheological behavior of a thermoreversible pmma-P n BA-PMMA triblock copolymer gel

Energy Technology Data Exchange (ETDEWEB)

Zabet, Mahla; Mishra, Satish; Boy, Ramiz; Walters, Keisha B.; Naskar, Amit K.; Kundu, Santanu (UO); (ORNL); (MSSU)

2017-03-25

Self-assembly and mechanical properties of triblock copolymers in a mid-block selective solvent are of interest in many applications. Herein, we report physical assembly of an ABA triblock copolymer, [PMMA–PnBA–PMMA] in two different mid-block selective solvents, n-butanol and 2-ethyl-1-hexanol. Gel formation resulting from end-block associations and the corresponding changes in mechanical properties have been investigated over a temperature range of -80 °C to 60 °C, from near the solvent melting points to above the gelation temperature. Shear-rheometry, thermal analysis, and small-angle neutron scattering data reveal formation and transition of structure in these systems from a liquid state to a gel state to a percolated cluster network with decrease in temperature. The aggregated PMMA end-blocks display a glass transition temperature. Our results provide new understanding into the structural changes of a self-assembled triblock copolymer gel over a large length scale and wide temperature range.

Correlations between phase behaviors and ionic conductivities of (ionic liquid + alcohol) systems

International Nuclear Information System (INIS)

Park, Nam Ku; Bae, Young Chan

2010-01-01

To understand the basic properties of ionic liquids (ILs), we examined the phase behavior and ionic conductivity characteristics using various compositions of different ionic liquids (1-ethyl-3-methylimidazolium hexafluorophosphate [emim] [PF6] and 1-benzyl-3-methylimidazolium hexafluorophosphate [bzmim] [PF6]) in several different alcohols (ethanol, propanol, 1-butanol, 2-butanol, and hexanol). We conducted a systematic study of the impact of different factors on the phase behavior of imidazolium-based ionic liquids in alcohols. Using a new experimental method with a liquid electrolyte system, we observed that the ionic conductivity of the ionic liquid/alcohol was sensitive to the surrounding temperature. We employed Chang et al.'s thermodynamic model [Chang et al. (1997, 1998) ] based on the lattice model. The obtained co-ordinated unit parameter from this model was used to describe the phase behavior and ionic conductivities of the given system. Good agreement with experimental data of various alcohol and ILs systems was obtained in the range of interest.

Glucose bioconversion profile in the syngas-metabolizing species Clostridium carboxidivorans.

Science.gov (United States)

Fernández-Naveira, Ánxela; Veiga, María C; Kennes, Christian

2017-11-01

Some clostridia produce alcohols (ethanol, butanol, hexanol) from gases (CO, CO 2 , H 2 ) and others from carbohydrates (e.g., glucose). C. carboxidivorans can metabolize both gases as well as glucose. However, its bioconversion profile on glucose had not been reported. It was observed that C. carboxidivorans does not follow a typical solventogenic stage when grown on glucose. Indeed, at pH 6.2, it produced first a broad range of acids (acetic, butyric, hexanoic, formic, and lactic acids), several of which are generally not found, under similar conditions, during gas fermentation. Medium acidification did not allow the conversion of fatty acids into solvents. Production of some alcohols from glucose was observed in C. carboxidivorans but at high pH rather than under acidic conditions, and the total concentration of those solvents was low. At high pH, formic acid was produced first and later converted to acetic acid, but organic acids were not metabolized at low pH. Copyright © 2017 Elsevier Ltd. All rights reserved.

New methodology for simultaneous volumetric and calorimetric measurements: Direct determination of {alpha}{sub p} and C{sub p} for liquids under pressure

Energy Technology Data Exchange (ETDEWEB)

Casas, L. M. [Departamento de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Plantier, F.; Bessieres, D. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes-UMR 5150, Universite de Pau et des Pays de l' Adour, BP 1155, 64013 Pau (France)

2009-12-15

A new batch cell has been developed to measure simultaneously both isobaric thermal expansion and isobaric heat capacity from calorimetric measurements. The isobaric thermal expansion is directly proportional to the linear displacement of an inner flexible below and the heat capacity is calculated from the calorimetric signal. The apparatus used was a commercial Setaram C-80 calorimeter and together with this type of vessels can be operated up to 20 MPa and in the temperature range of 303.15-523.15 K, In this work, calibration was carried out using 1-hexanol and subsequently both thermophysical properties were determined for 3-pentanol, 3-ethyl-3-pentanol, and 1-octanol at atmospheric pressure, 5 and 10 MPa, and from 303.15 to 423.15 K in temperature. Finally experimental values were compared with the literature in order to validate this new methodology, which allows a very accurate determination of isobaric thermal expansion and isobaric heat capacity.

Phytochemical, sensory attributes and aroma stability of dense phase carbon dioxide processed Hibiscus sabdariffa beverage during storage.

Science.gov (United States)

Ramírez-Rodrigues, Milena M; Plaza, Maria L; Azeredo, Alberto; Balaban, Murat O; Marshall, Maurice R

2012-10-01

The effect of dense phase carbon dioxide (DPCD) processing (34.5 MPa, 8% CO₂, 6.5 min, and 40 °C) on phytochemical, sensory and aroma compounds of hibiscus beverage was compared to a conventional thermal process (HTST) (75 °C for 15 s) and a control (untreated beverage) during refrigerated storage (4 °C). The overall likeability of the hibiscus beverage for all treatments was not affected by storage up to week 5. DPCD process retained more aroma volatiles as compared to HTST. Aroma profiles in the beverages were mainly composed of alcohols and aldehydes with 1-octen-3-ol, decanal, octanal, 1-hexanol, and nonanal as the compounds with the highest relative percentage peak areas. A loss of only 9% anthocyanins was observed for the DPCD processed hibiscus beverage. Phytochemical profiles in the hibiscus beverage included caffeoylquinic acids, anthocyanins, and flavonols. No major changes in total phenolics and antioxidant capacity occurred during the 14 weeks of storage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of Exogenous Abscisic Acid and Methyl Jasmonate on Anthocyanin Composition, Fatty Acids, and Volatile Compounds of Cabernet Sauvignon (Vitis vinifera L.) Grape Berries.

Science.gov (United States)

Ju, Yan-Lun; Liu, Min; Zhao, Hui; Meng, Jiang-Fei; Fang, Yu-Lin

2016-10-12

The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA) and methyl jasmonate (MeJA) on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC) and individual anthocyanins. Lipoxygenase (LOX) activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.

Density,Viscosity,Refractive Index,and Speed of Sound in Binary Mixtures of Pyridine and 1-Alkanols(C6,C7,C8,C10)at 303.15 K

Institute of Scientific and Technical Information of China (English)

ALI Anwar; TARIQ Mohd; NABI Firdosa; SHAHJAHAN

2008-01-01

The densities(ρ),viscosities(η),refractive indices(nD),and speeds of sound(u),of binary mixtures of pyridine with 1-hexanoi,1-heptanol,1-octanol and 1-decanol,including those of pure liquids,were measured over the entire composition range at 303.15 K and atmospheric pressure.From these experimental data,the values of excess molar volumes(VE),deviations in isentropic compressibilities(△ks),viscosities(△η),molar refractions(△Rm),apparent and partial molar volumes(Vφ,2 and V0φ,2 ),apparent and partial molar compressibilities(Kφ,2 and K0φ,2 ),of alkanols in pyridine and their corresponding deviations(△V and △K)were calculated.The variations of these parameters with composition of the mixtures suggest that the strength of interactions in these mixtures follow the order:1-hexanol 1-heptanol 1-octanol 1-decanol.All the excess and deviation functions were fitted to Redlich-Kister polynomial equation to determine the fitting coefficients and the standard deviations.

Analysis of volatiles from irradiated yeast extract

International Nuclear Information System (INIS)

Liao Tao; Li Xin; Zu Xiaoyan; Chen Yuxia; Geng Shengrong

2013-01-01

The method for determination volatiles from irradiated yeast extract (YE) using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed in this paper. The extraction conditions were optimized with reference to the peak area and number of volatiles as aldehyde, ketone, alcohol, acid, ester and sulfur compounds. The optimized conditions of HS-SPME for volatiles in irradiated YE were: divinyl benzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber, extration time 40 min, extraction temperature 40℃. The volatiles from YE irradiated by 0-19.8 kGy were detected using HS-SPME coupled with GC-MS. The results showed that only 15 volatiles were detected from no irradiated YE and main compounds were acetic acid, 2, 3-butanediol and 1-hexanol, 2-ethyl-. There were 40 volatiles detected from irradiated YE and the main compounds were acetic acid, phenylethyl alcohol, heptanal and nonanal. Compare to no irradiated yeast extract, the aldehyde, ketone, alkene and disulfide, dimethyl were produced by irradiating process. (authors)

Low-Temperature Reverse Microemulsion Synthesis, Characterization, and Photocatalytic Performance of Nanocrystalline Titanium Dioxide

Directory of Open Access Journals (Sweden)

Zhang Liu

2012-01-01

Full Text Available Nanocrystalline titanium dioxide (TiO2 was synthesized in microemulsions by using cetyltrimethylammonium bromide (CTAB as surfactant. In order to investigate the crystal transformation and photoactivity at low temperature, the as-prepared precipitates were aged at 65°C or calcined at various temperatures. Analyses using powder X-ray diffraction (XRD and Fourier transform infrared microscopy (FT-IR showed that precursors without aging or calcination were noncrystal and adsorbed by surfactant. After aging for 6 h, the amorphous TiO2 began to change into anatase. The obtained catalysts, which were synthesized in microemulsions with weight ratios of n-hexanol/CTAB/water as 6 : 3 : 1 and calcined at 500°C, presented the highest photocatalytic degradation rate on methyl orange (MO, while the catalysts, which were aged at 65°C for 90 h, also exhibited an outstanding photocatalytic performance and a little higher than that of the commercial titania photocatalyst Degussa P25.

A P,O,P′-tridentate mixed-donor scorpionate ligand: 6-[4,6-bis(diphenylphosphino-10H-phenoxazin-10-yl]hexan-1-ol

Directory of Open Access Journals (Sweden)

Holger B. Friedrich

2008-10-01

Full Text Available The title compound, C42H39NO2P2, is a P,O,P′-tridentate scorpionate-type ligand and has one molecule in the asymmetric unit. The angles involving the P atoms range from 100.21 (7 to 104.89 (7°. The N-hexanol group was found to be disordered and was refined over two positions with final occupancies of 0.683 (3 and 0.317 (3 which affected the C—O and C—N bond lengths. The bond lengths for C—O range from 1.402 (2 to 1.415 (2 Å and for C—N from 1.410 (2 to 1.448 (3 Å for the major disorder component; the corresponding ranges for the minor disorder component are 1.429 (3–1.408 (3 and 1.474 (3–1.474 (4 Å.

Emission of VOC's from modified rendering process

International Nuclear Information System (INIS)

Bhatti, Z.A.; Raja, I.A.; Saddique, M.; Langenhove, H.V.

2005-01-01

Rendering technique for processing of dead animal and slaughterhouse wastes into valuable products. It involves cooking of raw material and later Sterilization was added to reduce the Bovine Spongiform Encephalopathy (BSE). Studies have been carried out on rendering emission, with the normal cooking process. Our study shows, that the sterilization step in rendering process increases the emission of volatile organic compounds (VOC's). Gas samples, containing VOC's, were analyzed by the GC/MS (Gas Chromatograph and Mass Spectrometry). The most important groups of compounds- alcohols and cyclic hydrocarbons were identified. In the group of alcohol; 1-butanol, l-pentanol and l-hexanol compounds were found while in the group of cyclic hydrocarbon; methyl cyclopentane and cyclohexane compounds were detected. Other groups like aldehyde, sulphur containing compounds, ketone and furan were also found. Some compounds, like l-pentanol, 2-methyl propanal, dimethyl disulfide and dimethyl trisulfide, which belong to these groups, cause malodor. It is important to know these compounds to treat odorous gasses. (author)

Comparative study on heat pipe performance using aqueous solutions of alcohols

Energy Technology Data Exchange (ETDEWEB)

Senthilkumar, R.; Vaidyanathan, S.; Sivaraman, B. [Annamalai University, Department of Mechanical Engineering, Annamalai Nagar, Tamil Nadu (India)

2012-12-15

This paper deals with the performance characterization of heat pipes using an aqueous solution of long chain alcohols like n-Butanol, n-Pentanol, n-Hexanol and n-Heptanol as working mediums. These solutions are called as self-rewetting fluids, since these fluid mixtures possess a non-linear dependence of the surface tension with temperature. A cylindrical heat pipe made up of copper with two layers of wrapped screen is used as a wick material and partially filled with the self-rewetting fluid water mixture and tested for its heat transport capability like thermal efficiency and thermal resistance at different inclinations and input power levels. A number of tests have been performed with heat pipes, filled with various aqueous solutions of alcohols with a concentration of 2 ml/l in de-ionized water (DI water) on volume basis. The results obtained for heat pipes using self rewetting fluids show improved performances, when compared to DI water heat pipes. (orig.)

Optimization and characterization of a cemented ultimate-storage product

Science.gov (United States)

Brunner, H.

1981-12-01

The U- and Pu-containing packaging wastes can be homogeneously cemented after a washing and fragmentation process. Both finely crushed and coarsely fragmented raw wastes yield products with sufficient mechanical stability. The processability limit of the coarsely fragmented raw waste using cement paste or mortar is largely determined by the cellulose content, which is not to exceed 1.3% by weight in the end waste. Of 9 binders studied, the most corrosion-resistant products were obtained with blast-furnace slag cement, whereas poured concrete and Maxit are much less resistant in five-component brine. In the cemented product, hydrolysis of plasticizers (DOP) from plastics (PVC) occurs, leading to release of 2-ethyl-hexanol. This reaction occurs to a much lower degree with blast-furnace slag cement than with all other binders studied. The binder chosen for further tests consists of blast-furnace slag cement, concrete fluidizer and a stabilizer, and is processed at a W/C ratio of 0.43.

A safety assessment of branched chain saturated alcohols when used as fragrance ingredients

DEFF Research Database (Denmark)

Belsito, D.; Bickers, D.; Bruze, M.

2010-01-01

are between 0.001% and 1.7%, eye irritation is not a concern. The materials have no or low sensitizing potential. For individuals who are already sensitized, an elicitation reaction is possible. Due to lack of UVA/UVB light-absorbing structures, and review of phototoxic/photoallergy data, the BCSA...... are not expected to elicit phototoxicity or photoallergy. The 15 materials tested have a low order of acute toxicity. Following repeated application, seven BCSA tested were of low systemic toxicity. Studies performed on eight BCSA and three metabolites show no in vivo or in vitro genotoxicity. A valid...... carcinogenicity study showed that 2-ethyl-1-hexanol is a weak inducer of liver tumors in female mice, however, the relevance of this effect and mode of action to humans is still a matter of debate. The Panel is of the opinion that there are no safety concerns regarding BCSA under the present levels of use...

Quantifying the Contribution of Grape Hexoses to Wine Volatiles by High-Precision [U13C]-Glucose Tracer Studies

Science.gov (United States)

Nisbet, Mark A.; Tobias, Herbert J.; Brenna, J. Thomas; Sacks, Gavin L.; Mansfield, Anna Katharine

2016-01-01

Many fermentation volatiles important to wine aroma potentially arise from yeast metabolism of hexose sugars, but assessing the relative importance of these pathways is challenging due to high endogenous hexose substrate concentrations. To overcome this problem, gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure high-precision 13C/12C isotope ratios of volatiles in wines produced from juices spiked with tracer levels (0.01–1 APE) of uniformly labeled [U-13C]-glucose. The contribution of hexose to individual volatiles was determined from the degree of 13C enrichment. As expected, straight-chain fatty acids and their corresponding ethyl esters were derived almost exclusively from hexoses. Most fusel alcohols and their acetate esters were also majority hexose-derived, indicating the importance of anabolic pathways for their formation. Only two compounds were not derived primarily from hexoses (hexanol and isobutyric acid). This approach can be extended to other food systems or substrates for studying precursor–product relationships. PMID:24960193

Quantifying the contribution of grape hexoses to wine volatiles by high-precision [U¹³C]-glucose tracer studies.

Science.gov (United States)

Nisbet, Mark A; Tobias, Herbert J; Brenna, J Thomas; Sacks, Gavin L; Mansfield, Anna Katharine

2014-07-16

Many fermentation volatiles important to wine aroma potentially arise from yeast metabolism of hexose sugars, but assessing the relative importance of these pathways is challenging due to high endogenous hexose substrate concentrations. To overcome this problem, gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure high-precision (13)C/(12)C isotope ratios of volatiles in wines produced from juices spiked with tracer levels (0.01-1 APE) of uniformly labeled [U-(13)C]-glucose. The contribution of hexose to individual volatiles was determined from the degree of (13)C enrichment. As expected, straight-chain fatty acids and their corresponding ethyl esters were derived almost exclusively from hexoses. Most fusel alcohols and their acetate esters were also majority hexose-derived, indicating the importance of anabolic pathways for their formation. Only two compounds were not derived primarily from hexoses (hexanol and isobutyric acid). This approach can be extended to other food systems or substrates for studying precursor-product relationships.

Aromatically enhanced pear distillates from blanquilla and conference varieties using a packed column.

Science.gov (United States)

Arrieta-Garay, Yanine; García-Llobodanin, Laura; Pérez-Correa, José Ricardo; López-Vázquez, Cristina; Orriols, Ignacio; López, Francisco

2013-05-22

Pear distillates are generally produced from the Bartlett variety because of its rich aroma. In this study, a chemical and sensorial comparative examination of pear distillates from the three main varieties grown in Spain (Bartlett, Blanquilla, and Conference) using two distillation systems (copper Charentais alembic and packed column) was undertaken. Volatile compounds were identified by gas chromatography to differentiate the spirits according to pear variety and distillation method. The Bartlett distillates from both distillation systems possessed higher ethyl ester and acetate and lower cis-3-hexen-1-ol and 1-hexanol concentrations. Despite these differences, a sensory analysis panel could distinguish only the Bartlett alembic distillate from the alembic distillates of the other varieties. In contrast, the panel rated the packed-column distillates equally. Therefore, less aromatic pear varieties can be used to produce distillates with aromatic characteristics similar to those of the Bartlett variety if a suitable distillation process is used.

Effect of Exogenous Abscisic Acid and Methyl Jasmonate on Anthocyanin Composition, Fatty Acids, and Volatile Compounds of Cabernet Sauvignon (Vitis vinifera L. Grape Berries

Directory of Open Access Journals (Sweden)

Yan-Lun Ju

2016-10-01

Full Text Available The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA and methyl jasmonate (MeJA on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC and individual anthocyanins. Lipoxygenase (LOX activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.

Electroantennographic responses of New World screwworm to components of swormlure-4 and related compounds

International Nuclear Information System (INIS)

Cork, A.

1992-01-01

Electroantennographic (EAG) responses from New World screwworm flies were recorded as dose-response curves to the components of swormlure and to isobutyric acid, butanol, 1-hexanol, 1-octen-3-o1, 3-propylphenol and 3-methylindole. Among the swormlure components, good responses were obtained to valeric acid, phenol 4-methylphenol and indole. Only weaker responses were obtained to the butyl alcohols, dimethyldisulphide, acetic, butyric and benzoic acids. A strong response was obtained to 1-octen-3-o1, and the response to 3-methylindole was greater than that to indole. Responses of male and female flies were generally similar, except for those to dimethylsulphide and 4-methylphenol where responses fo males were greater than those of females. These studies indicate that EAG linked to gas chromatography should be a useful technique for detection of the biologically-active components in naturally-derived, volatile attractants, and suggest 1-octen-3-o1 and 3- methylindole should be tested for behavioural effects on NWS. 7 figs

Sorption of organic gases in residential bedrooms andbathrooms

Energy Technology Data Exchange (ETDEWEB)

Singer, B.C.; Hodgson, A.T.; Hotchi, T.; Ming, K.Y.; Sextro,R.G.; Wood, E.E.; Brown, N.J.

2005-01-05

Experiments were conducted to characterize organic gas sorption in residential bedrooms (n=4), bathrooms (n=2), and a furnished test chamber. Rooms were studied ''as-is'' with material surfaces and furnishings unaltered. Surface materials were characterized and areas quantified. Experiments included rapid volatilization of a volatile organic compound (VOC) mixture with the room closed and sealed for a 5-h Adsorb phase, followed by 30-min Flush and 2-h closed-room Desorb phases. The mixture included n-alkanes, aromatics, glycol ethers, 2-ethyl-1-hexanol, dichlorobenzene, and organophosphorus compounds. Measured gas-phase concentrations were fit to three variations of a mathematical model that considers sorption occurring at one surface sink and one potential embedded sink. The 2-parameter sink model tracked measurements for most compounds, but improved fits were obtained for some VOCs with a 3-parameter sink-diffusion or a 4-parameter two-sink model. Sorptive partitioning and initial adsorption rates increased with decreasing vapor pressure within each chemical class.

Batch and continuous extraction of bromelain enzyme by reversed micelles

Directory of Open Access Journals (Sweden)

Ana Maria Frattini Fileti

2009-10-01

Full Text Available The main aim of this study was to optimize the conditions for bromelain extraction by reversed micelles from pineapple juice (Ananas comosus. The purification was carried out in batch extraction and a micro-column with pulsed caps for continuous extraction. The cationic micellar solution was made of BDBAC as a surfactant, isooctane as a solvent and hexanol as a co-solvent. For the batch process, a purification factor of 3 times at the best values of surfactant agent, co-solvent and salt concentrations, pH of the back and forward extractions were, 100 mM, 10% v/v, 1 M, 3.5 and 8, respectively. For the continuous operation, independent variables optimal point was determined: ratio between light phase flow rate and total flow rate equal to 0.67 and 1 second for the time interval between the pulses. This optimal point led to a productivity of 1.29 mL/min and a purification factor of 4.96.Este trabalho teve como objetivo principal otimizar as condições para extração da bromelina do suco do abacaxi (Ananas comosus por micelas reversas. A purificação foi feita usando o processo de extração em batelada e contínuo, este último em uma micro-coluna de campânulas pulsantes. A solução micelar catiônica foi preparada com o surfactante BDBAC, i-octano como solvente e hexanol como co-solvente. Na extração em batelada encontrou-se um fator de purificação de 3 vezes, e seus melhores valores de concentração do agente surfactante, co-solvente e sal, de pH da re-extração e extração, foram respectivamente iguais a: 100 mM, 10% v/v, 1 M, 3,5 e 8. Para a operação contínua, as variáveis independentes ótimas foram: 0,67 para a razão entre as taxas de fluxos da fase leve e a total e 1 s para o intervalo de tempo entre pulsos das campânulas. Este ponto ótimo leva a uma produtividade de 1,29 mL/min e a um fator de purificação igual a 4,96.

Structural Properties of Pure Simple Alcohols from Ethanol, Propanol, Butanol, Pentanol, to Hexanol: Comparing Monte Carlo Simulations with Experimental SAXS Data

Czech Academy of Sciences Publication Activity Database

Tomšič, M.; Jamnik, A.; Fritz-Popovski, G.; Glatter, O.; Vlček, Lukáš

2007-01-01

Roč. 111, č. 7 (2007), s. 1738-1751 ISSN 1520-6106 Institutional research plan: CEZ:AV0Z40720504 Keywords : alcohols * saxs * monte carlo Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.086, year: 2007

Preparation of mesoporous MnO2/C catalyst for n-hexyl acetate synthesis

International Nuclear Information System (INIS)

Yang Zeheng; Pan Yanmei; Mei Zhousheng; Zhang Weixin

2012-01-01

A mesoporous MnO 2 /C composite was prepared by impregnating self-made porous carbon spheres with manganese nitrate aqueous solution and subsequently reacting with KMnO 4 aqueous solution. It was characterized with X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), the Brunauer-Emmett-Teller (BET) surface area and the Barrett-Joyner-Halenda (BJH) pore size distribution. The as-prepared mesoporous MnO 2 /C composite was used as catalyst for the synthesis of n-hexyl acetate, and the effects of MnO 2 loading and esterification reaction parameters on the esterification rate were investigated. The results prove that MnO 2 loading has a significant effect on the catalytic activity and that the mesoporous MnO 2 /C composite exhibits high catalytic activity with an esterification rate of 96.42% under the conditions below: MnO 2 loading (73.09 wt%), catalyst dosage (0.1% in total weight), acetic acid/n-hexanol molar ratio (2:1), reaction temperature (130 °C) and reaction time (5 h).

Highly versatile fiber-based optical Fabry-Pérot gas sensor.

Science.gov (United States)

Liu, Jing; Sun, Yuze; Fan, Xudong

2009-02-16

We develop a versatile, compact, and sensitive fiber-based optical Fabry-Pérot (FP) gas sensor. The sensor probe is composed of a silver layer and a vapor-sensitive polymer layer that are sequentially deposited on the cleaved fiber endface, thus forming an FP cavity. The interference spectrum resulting from the reflected light at the silver-polymer and polymer-air interfaces changes when the polymer is exposed to gas analytes. This structure enables using any polymer regardless of the polymer refractive index (RI), which significantly enhances the sensor versatility. In experiments, we use polyethylene glycol (PEG) 400 (RI=1.465-1.469) and Norland Optical Adhesive (NOA) 81 (RI=1.53-1.56) as the gas sensing polymer and show drastically different sensor response to hexanol, methanol, and acetone. The estimated sensitivity for methanol vapor is 3.5 pm/ppm and 0.1 pm/ppm for PEG 400 and NOA 81, respectively, with a detection limit on the order of 1-10 ppm. Gas sensing for the analytes delivered in both continuous flow mode and pulsed mode is demonstrated.

Synthesis of Zn/Co/Fe-layered double hydroxide nanowires with controllable morphology in a water-in-oil microemulsion

Energy Technology Data Exchange (ETDEWEB)

Wu Hongyu; Jiao Qingze [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Zhao Yun, E-mail: zhaoyun@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Huang Silu; Li Xuefei; Liu Hongbo; Zhou Mingji [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China)

2010-02-15

The Zn/Co/Fe-layered double hydroxide nanowires were synthesized via a reverse microemulsion method by using cetyltrimethyl ammonium bromide (CTAB) /n-hexane/n-hexanol/water as Soft-Template. ZnSO{sub 4}, CoSO{sub 4}, Fe{sub 2}(SO{sub 4}){sub 3} and urea were used as raw materials. The influence of reaction temperature, time, urea concentration and Cn (molar ratio of cetyltrimethyl ammonium bromide to water) on the structure and morphology of Zn/Co/Fe-layered double hydroxides was investigated. The samples were characterized using Transmission Electron Microscopy (TEM), Inductively Coupled Plasma (ICP), X-ray Diffraction (XRD) and Infrared Absorption Spectrum (IR). The results indicate that higher temperature is beneficial to the formation of layered double hydroxides, but particles apart from nanowires could be produced if temperature is up to 120 deg. C. By varying the temperature, reaction time, urea concentration and Cn, we got the optimum conditions of synthesizing uniform Zn/Co/Fe-layered double hydroxide nanowires: 100 deg. C, more than 12 h, Cn: 30-33, urea concentration: 0.3 M.

Metabolome based volatiles profiling in 13 date palm fruit varieties from Egypt via SPME GC-MS and chemometrics.

Science.gov (United States)

Khalil, Mohammed N A; Fekry, Mostafa I; Farag, Mohamed A

2017-02-15

Dates (Phoenix dactylifera L.) are distributed worldwide as major food complement providing a source of sugars and dietary fiber as well as macro- and micronutrients. Although phytochemical analyses of date fruit non-volatile metabolites have been reported, much less is known about the aroma given off by the fruit, which is critical for dissecting sensory properties and quality traits. Volatile constituents from 13 date varieties grown in Egypt were profiled using SPME-GCMS coupled to multivariate data analysis to explore date fruit aroma composition and investigate potential future uses by food industry. A total of 89 volatiles were identified where lipid-derived volatiles and phenylpropanoid derivatives were the major components of date fruit aroma. Multivariate data analyses revealed that 2,3-butanediol, hexanal, hexanol and cinnamaldehyde contributed the most to classification of different varieties. This study provides the most complete map of volatiles in Egyptian date fruit, with Siwi and Sheshi varieties exhibiting the most distinct aroma among studied date varieties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Active disturbance rejection controller for chemical reactor

International Nuclear Information System (INIS)

Both, Roxana; Dulf, Eva H.; Muresan, Cristina I.

2015-01-01

In the petrochemical industry, the synthesis of 2 ethyl-hexanol-oxo-alcohols (plasticizers alcohol) is of high importance, being achieved through hydrogenation of 2 ethyl-hexenal inside catalytic trickle bed three-phase reactors. For this type of processes the use of advanced control strategies is suitable due to their nonlinear behavior and extreme sensitivity to load changes and other disturbances. Due to the complexity of the mathematical model an approach was to use a simple linear model of the process in combination with an advanced control algorithm which takes into account the model uncertainties, the disturbances and command signal limitations like robust control. However the resulting controller is complex, involving cost effective hardware. This paper proposes a simple integer-order control scheme using a linear model of the process, based on active disturbance rejection method. By treating the model dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. Simulation results are provided to demonstrate the effectiveness of the proposed method

Active disturbance rejection controller for chemical reactor

Energy Technology Data Exchange (ETDEWEB)

Both, Roxana; Dulf, Eva H.; Muresan, Cristina I., E-mail: roxana.both@aut.utcluj.ro [Technical University of Cluj-Napoca, 400114 Cluj-Napoca (Romania)

2015-03-10

In the petrochemical industry, the synthesis of 2 ethyl-hexanol-oxo-alcohols (plasticizers alcohol) is of high importance, being achieved through hydrogenation of 2 ethyl-hexenal inside catalytic trickle bed three-phase reactors. For this type of processes the use of advanced control strategies is suitable due to their nonlinear behavior and extreme sensitivity to load changes and other disturbances. Due to the complexity of the mathematical model an approach was to use a simple linear model of the process in combination with an advanced control algorithm which takes into account the model uncertainties, the disturbances and command signal limitations like robust control. However the resulting controller is complex, involving cost effective hardware. This paper proposes a simple integer-order control scheme using a linear model of the process, based on active disturbance rejection method. By treating the model dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. Simulation results are provided to demonstrate the effectiveness of the proposed method.

Atmospheric pressure chemical ionisation mass spectrometry analysis linked with chemometrics for food classification - a case study: geographical provenance and cultivar classification of monovarietal clarified apple juices.

Science.gov (United States)

Gan, Heng-Hui; Soukoulis, Christos; Fisk, Ian

2014-03-01

In the present work, we have evaluated for first time the feasibility of APCI-MS volatile compound fingerprinting in conjunction with chemometrics (PLS-DA) as a new strategy for rapid and non-destructive food classification. For this purpose 202 clarified monovarietal juices extracted from apples differing in their botanical and geographical origin were used for evaluation of the performance of APCI-MS as a classification tool. For an independent test set PLS-DA analyses of pre-treated spectral data gave 100% and 94.2% correct classification rate for the classification by cultivar and geographical origin, respectively. Moreover, PLS-DA analysis of APCI-MS in conjunction with GC-MS data revealed that masses within the spectral ACPI-MS data set were related with parent ions or fragments of alkyesters, carbonyl compounds (hexanal, trans-2-hexenal) and alcohols (1-hexanol, 1-butanol, cis-3-hexenol) and had significant discriminating power both in terms of cultivar and geographical origin. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Synthesis, Characterization and Catalytic Performance in the Selective Oxidation of Alcohols by Metallophthalocyanines Supported on Zinc Oxide Nanoparticles

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Amin Ebadi

2017-01-01

Full Text Available Unsubstituted phthalocyanines of Co, Fe and Mn supported on zinc oxide nanoparticles were prepared and were well characterized with X-ray diffraction and scanning electron microscopy. The oxidation of alcohols with tert-butylhydroperoxide, in the presence of metallophthalocyanines supported on zinc oxide nanoparticles was investigated. These MPc/ZnO nanocomposites were effective catalysts for the oxidation of alcohols such as cyclohexanol (83.4% conversion; 100% selectivity, benzyl alcohol (70.5% conversion; 100% selectivity and hexanol (62.3% conversion; 100% selectivity. The influences of reaction time, various metals and type of substrates and oxidants on the oxidation of alcohols were also studied, and optimized conditions were investigated. Under these reaction conditions, the activity of the catalysts decreases in the following order:  CoPc/nano-ZnO > FePc/nano-ZnO > MnPc/nano-ZnO. It shows that TBHP is more efficient oxidant due to weaker O-O bond with respect to H2O2 and the following order has been observed for the percentage of conversions of alcohols: 2º > benzylic > 1º.

Solvated electrons at elevated temperatures in different alcohols: Temperature and molecular structure effects

Energy Technology Data Exchange (ETDEWEB)

Yan, Yu [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Lin, Mingzhang [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Katsumura, Yosuke, E-mail: katsu@n.t.u-tokyo.ac.j [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Nuclear Professional School, Graduate School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Fu, Haiying; Muroya, Yusa [Nuclear Professional School, Graduate School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan)

2010-12-15

The absorption spectra of solvated electrons in pentanol, hexanol and octanol are measured from 22 to 200, 22 to 175 and 50 to150 {sup o}C, respectively, at a fixed pressure of 15 MPa, using nanosecond pulse radiolysis technique. The results show that the peak positions of the absorption spectra have a red-shift (shift to longer wavelengths) as temperature increases, similar to water and other alcohols. Including the above mentioned data, a compilation of currently available experimental data on the energy of absorption maximum (E{sub max}) of solvated electrons changed with temperature in monohydric alcohols, diols and triol is presented. E{sub max} of solvated electron is larger in those alcohols that have more OH groups at all the temperatures. The molecular structure effect, including OH numbers, OH position and carbon chain length, is investigated. For the primary alcohols with same OH group number and position, the temperature coefficient increases with increase in chain length. For the alcohols with same chain length and OH numbers, temperature coefficient is larger for the symmetric alcohols than the asymmetric ones.

Volatile Flavor Compounds Produced by Molds of Aspergillus, Penicillium, and Fungi imperfecti.

Science.gov (United States)

Kaminski, E; Stawicki, S; Wasowicz, E

1974-06-01

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.

Synthesis of 9,9,9-trideutero-1,4-dihydroxynonane mercapturic acid (d3-DHN-MA), a useful internal standard for DHN-MA urinalysis.

Science.gov (United States)

Chantegrel, B; Deshayes, C; Doutheau, A; Steghens, J P

2002-10-01

Racemic 1,4-dihydroxynonane mercapturic acid (DHN-MA) and 9,9,9-trideutero-1,4-dihydroxynonane mercapturic acid (d3-DHN-MA) are synthesized on a 400-mg scale (overall yield approximately 40%) by a two-step sequence involving Michael addition of N-acetyl-L-cysteine to methyl 4-hydroxynon-2(E)-enoate or methyl 9,9,9-trideutero-4-hydroxynon-2 (E)-enoate, followed by reduction of the intermediate adducts with lithium borohydride. The requisite starting methyl esters are obtained, respectively, from heptanal or 7,7,7-trideuteroheptanal and methyl 4-chlorophenylsulfinylacetate via a sulfoxide piperidine and carbonyl reaction described in the literature. The 7,7,7-trideuteroheptanal is easily prepared by classical methods in four steps from 6-bromo-1-hexanol. 13C NMR data indicate that DHN-MA as well as d3-DHN-MA are obtained as mixtures of four diastereomers. Preliminary results show that d3-DHN-MA could be used as an internal standard for mass spectrometric quantification of DHN-MA in human urine.

A thermodynamic approach to assess organic solute adsorption onto activated carbon in water

KAUST Repository

De Ridder, David J.; Verliefde, Arne R. D.; Heijman, Bas G J; Gelin, Simon; Pereira, Manuel Fernando Ribeiro; Rocha, Raquel P.; Figueiredo, José Luí s M; Amy, Gary L.; Van Dijk, Hans C.

2012-01-01

In this paper, the hydrophobicity of 13 activated carbons is determined by various methods; water vapour adsorption, immersion calorimetry, and contact angle measurements. The quantity and type of oxygen-containing groups on the activated carbon were measured and related to the methods used to measure hydrophobicity. It was found that the water-activated carbon adsorption strength (based on immersion calorimetry, contact angles) depended on both type and quantity of oxygen-containing groups, while water vapour adsorption depended only on their quantity. Activated carbon hydrophobicity measurements alone could not be related to 1-hexanol and 1,3-dichloropropene adsorption. However, a relationship was found between work of adhesion and adsorption of these solutes. The work of adhesion depends not only on activated carbon-water interaction (carbon hydrophobicity), but also on solute-water (solute hydrophobicity) and activated carbon-solute interactions. Our research shows that the work of adhesion can explain solute adsorption and includes the effect of hydrogen bond formation between solute and activated carbon. © 2012 Elsevier Ltd. All rights reserved.

Determination of volatile organic compounds responsible for flavour in cooked river buffalo meat

Directory of Open Access Journals (Sweden)

A. Di Luccia

2010-02-01

Full Text Available Flavour is an important consumer attractive that directly influences the success of food products on the market. The determination of odorous molecules and their identification allows to useful knowledge for producers to valorise their own products. Buffalo meat has a different chemical composition from pork and beef and requires some cautions in cooking and processing. This work aims at the identification of volatile molecules responsible for flavours in river buffalo meat. The determination was carried out by solid phase micro-extraction (SPME technique and analysed by gas chromatography coupled to mass spectrometry (GC-MS. The most relevant results were the higher odorous impact of buffalo meat and the higher content of sulphide compounds responsible for wild aroma respect to pork and beef. These results were obtained comparing the total area of peaks detected in every chromatogram. We have also found significant differences concerning the contents of pentadecane, 1-hexanol-2 ethyl, butanoic acid, furano-2-penthyl. The origin of volatile organic compounds and their influence on the river buffalo aromas were discussed.

Titanium dioxide antireflection coating for silicon solar cells by spray deposition

Science.gov (United States)

Kern, W.; Tracy, E.

1980-01-01

A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

A thermodynamic approach to assess organic solute adsorption onto activated carbon in water

KAUST Repository

De Ridder, David J.

2012-08-01

In this paper, the hydrophobicity of 13 activated carbons is determined by various methods; water vapour adsorption, immersion calorimetry, and contact angle measurements. The quantity and type of oxygen-containing groups on the activated carbon were measured and related to the methods used to measure hydrophobicity. It was found that the water-activated carbon adsorption strength (based on immersion calorimetry, contact angles) depended on both type and quantity of oxygen-containing groups, while water vapour adsorption depended only on their quantity. Activated carbon hydrophobicity measurements alone could not be related to 1-hexanol and 1,3-dichloropropene adsorption. However, a relationship was found between work of adhesion and adsorption of these solutes. The work of adhesion depends not only on activated carbon-water interaction (carbon hydrophobicity), but also on solute-water (solute hydrophobicity) and activated carbon-solute interactions. Our research shows that the work of adhesion can explain solute adsorption and includes the effect of hydrogen bond formation between solute and activated carbon. © 2012 Elsevier Ltd. All rights reserved.

Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles.

Science.gov (United States)

Li, Pengyan; Zhu, Junwei; Qin, Yuchuan

2012-08-01

Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most serious pests of Brassicaceae crops worldwide. Electrophysiological and behavioral responses of P. xylostella to green leaf volatiles (GLVs) alone or together with its female sex pheromone were investigated in laboratory and field. GLVs 1-hexanol and (Z)-3-hexen-1-ol elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relatively weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactometer experiments. (E)-2-Hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate induced attraction of males, reaching up to 50%, significantly higher than the response to the unbaited control arm. In field experiments conducted in 2008 and 2009, significantly more moths were captured in traps baited with synthetic sex pheromone with either (Z)-3-hexenyl acetate alone or a blend of (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, and (E)-2-hexenal compared with sex pheromone alone and other blend mixtures. These results demonstrated that GLVs could be used to enhance the attraction of P. xylostella males to sex pheromone-baited traps.

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

Directory of Open Access Journals (Sweden)

Harle Arti

2008-01-01

Full Text Available AbstractSulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+–malic acid chelate (0.05 M aqueous solution was studied in w/o microemulsion containing cyclohexane, Triton X-100 andn-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD, transmission electron microscope (TEM, energy dispersive spectroscopy (EDS, diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm and narrow particle size distribution (in range of 5–15 nm as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%. Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi than that of colloidal sulfur.

Production of alkyl esters from macaw palm oil by a sequential hydrolysis/esterification process using heterogeneous biocatalysts: optimization by response surface methodology.

Science.gov (United States)

Bressani, Ana Paula P; Garcia, Karen C A; Hirata, Daniela B; Mendes, Adriano A

2015-02-01

The present study deals with the enzymatic synthesis of alkyl esters with emollient properties by a sequential hydrolysis/esterification process (hydroesterification) using unrefined macaw palm oil from pulp seeds (MPPO) as feedstock. Crude enzymatic extract from dormant castor bean seeds was used as biocatalyst in the production of free fatty acids (FFA) by hydrolysis of MPPO. Esterification of purified FFA with several alcohols in heptane medium was catalyzed by immobilized Thermomyces lanuginosus lipase (TLL) on poly-hydroxybutyrate (PHB) particles. Under optimal experimental conditions (mass ratio oil:buffer of 35% m/m, reaction temperature of 35 °C, biocatalyst concentration of 6% m/m, and stirring speed of 1,000 rpm), complete hydrolysis of MPPO was reached after 110 min of reaction. Maximum ester conversion percentage of 92.4 ± 0.4% was reached using hexanol as acyl acceptor at 750 mM of each reactant after 15 min of reaction. The biocatalyst retained full activity after eight successive cycles of esterification reaction. These results show that the proposed process is a promising strategy for the synthesis of alkyl esters of industrial interest from macaw palm oil, an attractive option for the Brazilian oleochemical industry.

Fabrication of yttria microcapsules for radiotherapy from water/oil emulsion

International Nuclear Information System (INIS)

Miyazaki, Toshiki; Kai, Tomohiro; Ishida, Eiichi; Kawashita, Masakazu; Hiraoka, Masahiro

2010-01-01

Radiotherapy using ceramic microparticles that act as β-emitters after neutron bombardment is attractive as a minimally invasive option for cancer treatment. Yttria (Y 2 O 3 ) microcapsules (20-30 μm in diameter) are capable of cutting off the nutrition supply in cancer cells through an embolization effect. In the present study, Y 2 O 3 microcapsules were prepared via precipitation of yttrium hydroxide from a water/oil (W/O) emulsion and a subsequent heat treatment. The emulsion was prepared by dispersing yttrium hydroxide sol in 2-ethyl-1-hexanol. Microcapsules were obtained by an addition of the emulsion in butanol via dehydration and subsequent aggregation of the yttrium hydroxide. The effects of the rotation speed and surfactant concentration on the diameter of the particles were investigated. The diameter of the microcapsules showed a tendency to decrease with increases in rotation speed during emulsion preparation or surfactant concentration in the oil phase. A high yield of the Y 2 O 3 microcapsules with a diameter of 20-30 μm were obtained after a heat treatment at the optimized rotation speed and surfactant concentration. The obtained microcapsules showed high chemical durability in a simulated body environment. (author)

Excess molar volumes and viscosities of (1,1,2,2-tetrabromoethane + 1-alkanols) at T = (293.15 and 303.15) K

International Nuclear Information System (INIS)

Al-Hayan, M.N.M.; Abdul-latif, Abdul-Haq M.

2006-01-01

Density and viscosity measurements for binary mixtures of (1,1,2,2-tetrabromoethane + 1-pentanol, or + 1-hexanol, or + 1-heptanol, or + 1-octanol, or + 1-decanol) at T = (293.15 and 303.15) K, have been conducted at atmospheric pressure. The excess molar volumes V E , have been calculated from the experimental measurements, and the results were fitted to Redlich-Kister equation. The viscosity data were correlated with the model of Grunberg and Nissan, and McAllister four-body model. The excess molar volumes of (1,1,2,2-tetrabromoethane + 1-pentanol, or + 1-haxanol, or + 1-heptanol, or + 1-octanol) had a sigmoidal shape and the values varied from negative to positive with the increase in the molar fraction of 1,1,2,2-tetrabromoethane. The remaining binary mixture of (1,1,2,2-tetrabromoethane + 1-decanol) was positive over the entire composition range. The effects of the 1-alkanol chain length as well as the temperature on the excess molar volume have been studied. The results have been qualitatively used to explain the molecular interaction between the components of these mixtures

Detailed kinetic modeling study of n-pentanol oxidation

KAUST Repository

Heufer, Karl Alexander; Sarathy, Mani; Curran, Henry J.; Davis, Alexander C.; Westbrook, Charles K.; Pitz, William J.

2012-01-01

To help overcome the world's dependence upon fossil fuels, suitable biofuels are promising alternatives that can be used in the transportation sector. Recent research on internal combustion engines shows that short alcoholic fuels (e.g., ethanol or n-butanol) have reduced pollutant emissions and increased knock resistance compared to fossil fuels. Although higher molecular weight alcohols (e.g., n-pentanol and n-hexanol) exhibit higher reactivity that lowers their knock resistance, they are suitable for diesel engines or advanced engine concepts, such as homogeneous charge compression ignition (HCCI), where higher reactivity at lower temperatures is necessary for engine operation. The present study presents a detailed kinetic model for n-pentanol based on modeling rules previously presented for n-butanol. This approach was initially validated using quantum chemistry calculations to verify the most stable n-pentanol conformation and to obtain C-H and C-C bond dissociation energies. The proposed model has been validated against ignition delay time data, speciation data from a jet-stirred reactor, and laminar flame velocity measurements. Overall, the model shows good agreement with the experiments and permits a detailed discussion of the differences between alcohols and alkanes. © 2012 American Chemical Society.

Study of the volatile compounds from plum (Prunus domestica L. cv. Horvin and estimation of their contribution to the fruit aroma

Directory of Open Access Journals (Sweden)

Jorge Antonio Pino

2012-03-01

Full Text Available Simultaneous Distillation-Extraction (SDE and headspace-solid phase microextraction (HS-SPME combined with GC-FID and GC-MS were used to analyze volatile compounds from plum (Prunus domestica L. cv. Horvin and to estimate the most odor-active compounds by application of the Odor Activity Values (OAV. The analyses led to the identification of 148 components, including 58 esters, 23 terpenoids, 14 aldehydes, 11 alcohols, 10 ketones, 9 alkanes, 7 acids, 4 lactones, 3 phenols, and other 9 compounds of different structures. According to the results of SDE-GC-MS, SPME-GC-MS and OAV, ethyl 2-methylbutanoate, hexyl acetate, (E-2-nonenal, ethyl butanoate, (E-2-decenal, ethyl hexanoate, nonanal, decanal, (E-β-ionone, Γ-dodecalactone, (Z-3-hexenyl acetate, pentyl acetate, linalool, Γ-decalactone, butyl acetate, limonene, propyl acetate, Δ-decalactone, diethyl sulfide, (E-2-hexenyl acetate, ethyl heptanoate, (Z-3-hexenol, (Z-3-hexenyl hexanoate, eugenol, (E-2-hexenal, ethyl pentanoate, hexyl 2-methylbutanoate, isopentyl hexanoate, 1-hexanol, Γ-nonalactone, myrcene, octyl acetate, phenylacetaldehyde, 1-butanol, isobutyl acetate, (E-2-heptenal, octadecanal, and nerol are characteristic odor active compounds in fresh plums since they showed concentrations far above their odor thresholds.

Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

Science.gov (United States)

Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

1995-01-01

The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

Spectroscopic Analysis of 10MAG/LDAO Reverse Micelles to Determine Characteristic Properties and Behavioral Extrema

Science.gov (United States)

Berg, Joshua; Mawson, Cara; Norris, Zach; Nucci, Nathaniel

Reverse micelles are spontaneously organizing complexes of surfactant that encapsulate a nanoscale pool of water in a bulk non-polar solvent. Reverse micelle (RM) mixtures have a wide range of applications, including biophysical investigation of protein systems. A new RM mixture composed of decyl-1-monoglycerol (10MAG) and lauryldimethylammonium-N-oxide (LDAO) was recently described. This mixture has the potential to prove more widely applicable for use of RMs in applications that involve encapsulation of macromolecules, yet little is known about the phase behavior or size of reverse micelles created by this mixture. Data describing such behaviors for this mixture are presented here. We have used dynamic light scattering (DLS) and fluorescence spectroscopy to investigate the size and partitioning behavior of RMs in varying mixtures of 10MAG, LDAO, water, pentane, and hexanol. These data demonstrate that the 10MAG/LDAO RM mixture exhibits markedly different phase and RM size behavior than that of commonly used RM surfactant mixtures. The implications of these findings for use of the 10MAG/LDAO mix for RM applications will also be addressed. Funding provided by Rowan University.

Solid-phase extraction element based on epoxy polymer monolith for determination of polar organic compounds in aqueous media.

Science.gov (United States)

Takahashi, Tadashi; Odagiri, Kayo; Watanabe, Atsushi; Watanabe, Chuichi; Kubo, Takuya; Hosoya, Ken

2011-10-01

A solid-phase extraction element based on epoxy polymer monolith was fabricated for sorptive enrichment of polar compounds from liquid and gaseous samples. After ultrasonication of the element in an aqueous solution for a given period of time, the thermal desorption (TD) using a pyrolyzer with gas chromatography/mass spectrometry (GC/MS), in which TD temperature was programmed from 50 to 250 °C for the analytes absorbed in the element, was used to evaluate the element for basic extraction performance using the aqueous standard mixtures consisting of compounds having varied polarities such as hexanol, isoamyl acetate, linalool, furfural and decanoic acid, in concentrations ranging from 10 μg/L to 1 mg/L. Excellent linear relationships were observed for all compounds in the standard mixture, except decanoic acid. In the extraction of beverages such as red wine, the extraction element showed stronger adsorption characteristics for polar compounds such as alcohols and acids than a non-polar polydimethylsiloxane-based element. This feature is derived from the main polymer structure along with hydroxyl and amino groups present in the epoxy-based monolith polymer matrix. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In-syringe magnetic-stirring-assisted liquid-liquid microextraction for the spectrophotometric determination of Cr(VI) in waters.

Science.gov (United States)

Henríquez, Camelia; Horstkotte, Burkhard; Solich, Petr; Cerdà, Víctor

2013-08-01

A fully automated method for the determination of chromate is described. It is based on the selective reaction of Cr(VI) with diphenylcarbazide in acidic media to form a colored complex of Cr(III) with the oxidation product diphenylcarbazone. The reaction was performed within the syringe of an automatic burette containing a magnetic stirrer for homogenization of the sample and the required reagents. In-syringe stirring was made possible using a specially designed driving device placed around the syringe barrel to achieve a rotating magnetic field in the syringe, forcing the stirrer to spin. In a second step, the reaction mixture in the syringe was neutralized to allow in-syringe magnetic-stirring-assisted dispersive liquid-liquid microextraction of the complex into 125 μL of n-hexanol. After phase separation by droplet flotation over 30 s, the organic phase was propelled into a coupled spectrophotometric detection cell. The entire multistep procedure including in-system standard preparation was done within 270 s. The method was used for the analysis of natural waters, achieving average analyte recovery of 103%, a limit of detection of 0.26 μg L(-1), and a repeatability of less than 4% relative standard deviation.

Controllable synthesis, characterization and optical properties of ZnS:Mn nanoparticles as a novel biosensor

International Nuclear Information System (INIS)

Mohagheghpour, E.; Rabiee, M.; Moztarzadeh, F.; Tahriri, M.; Jafarbeglou, M.; Bizari, D.; Eslami, H.

2009-01-01

To be a suitable biolabeling agent (biosensor), the nanoparticles should have high luminescent efficiency and proper surface groups for coupling with biomolecules. In this article, high-quality ZnS:Mn nanoparticles were synthesized from quaternary W/O micro-emulsion system with different Mn% for detecting the best concentration. The addition of biotin and the subsequent specific binding events alter the dielectric environment of the nanoparticle, resulting in a spectral shift of the particle plasmon resonance. Cyclohexane was used as oil, Triton X-100 as surfactant, n-hexanol as a co-surfactant and mercaptoethanol and thioglycolic acid for the best linking of the biological part to the nanoparticle (as linking agents). Surfactant and co-surfactant produce a stable emulsion with connection to the surface of nanoparticles and prevention from contacting together. For qualitative and quantitative analyses of this product scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), inductive coupled plasma (ICP), zeta meter for measurement ZP and spectrograph techniques are used. The results showed that with reducing particle size, emission shifted to the lower wavelengths. In addition, with conjugation between avidin and biotin by mercaptoethanol in biologic media, spectral emission decreased.

Structural and phase transition changes of sodium dodecyl sulfate micellar solution in alcohols probed by small-angle neutron scattering (SANS)

Energy Technology Data Exchange (ETDEWEB)

Putra, Edy Giri Rachman [Neutron Scattering Laboratory, National Nuclear Energy Agency of Indonesia (BATAN), Gedung 40 BATAN, Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia); Patriati, Arum [Neutron Scattering Laboratory, National Nuclear Energy Agency of Indonesia (BATAN), Gedung 40 BATAN, Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia); Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Gadjah Mada, Bulaksumur, Yogyakarta 55281, Indonesia giri@batan.go.id (Indonesia)

2015-04-16

Small-angle neutron scattering (SANS) measurements on 0.3M sodium dodecyl sulfate (SDS) micellar solutions have been performed in the presence of n-alcohols, from ethanol to decanol at different alcohol concentrations, 2–10 wt%. The ellipsoid micellar structure which occurred in the 0.3M SDS in aqueous solution with the size range of 30–50 Å has different behavior at various hydrocarbon chain length and concentration of alcohols. At low concentration and short chain-length of alcohols, such as ethanol, propanol, and butanol, the size of micelles reduced and had a spherical-like structure. The opposite effect occurred as medium to long chain alcohols, such as hexanol, octanol and decanol was added into the 0.3M SDS micellar solutions. The micelles structure changed to be more elongated in major axis and then crossed the critical phase transition from micellar solution into liquid crystal phase as lamellar structure emerged by further addition of alcohols. The inter-lamellar distances were also depending on the hydrocarbon chain length and concentration of alcohols. In the meantime, the persistent micellar structures occurred in addition of medium chain of n-alcohol, pentanol at all concentrations.

Volatile organic chemicals of a shore-dwelling cyanobacterial mat community.

Science.gov (United States)

Evans, W G

1994-02-01

The main components of a cyanobacterial mat community of a hypersaline lake shore consist of edaphic, mat-forming strains (ecophenes), and littoral strains ofOscillatoria animalis Agardh andO. subbrevis Schmidle, other microorganisms associated with these cyanobacteria, several species ofBembidion (Carabidae: Coleoptera), and two halophytic flowering plants:Puccinellia nuttalliana (salt meadow grass) andSalicornia europaea rubra (samphire). The volatile organic compounds of this community are a blend of those emitted by each of these components such as the C17 alka(e)nes, geosmin, 2-methylisoborneol,β-cyclocitral,β-ionone, dimethyl sulfide, and dimethyl trisulfide of cyanobacteria and associated microorganisms; alcohols, esters, and aldehydes usually associated with flowering plants; and possibly some insect-derived esters, particularly isopropyl tetradecanoate. The dominant compounds were: C11, C13, C15, and C17 alka(e)nes, methyl esters of C16 and C18:2 acids, isopropyl tetradecanoate, heptanal, 3-octanone and 2-nonanone, the acyclic terpene linalool, and the alcohols 1-heptanol, 1-hexanol, 1-octanol, 3-hexen-1-ol, and 2-octen-1-ol. It is concluded that this community may be distinguished from related communities by its repertoire of volatile organic compounds.

The Changes in Color, Soluble Sugars, Organic Acids, Anthocyanins and Aroma Components in “Starkrimson” during the Ripening Period in China

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Yulian Liu

2016-06-01

Full Text Available “Starkrimson” is a traditional apple cultivar that was developed a long time ago and was widely cultivated in the arid region of the northern Wei River of China. However, little information regarding the quality characteristics of “Starkrimson” fruit has been reported in this area. To elucidate these characteristics, the color, soluble sugars, organic acids, anthocyanins and aroma components were measured during the ripening period through the use of high performance liquid chromatography (HPLC and gas chromatography-mass spectrometry (GC-MS. The results indicated that the changes in anthocyanin contents took place later than the changes in the Commission International Eclairage (CIE parameters. Meanwhile, cyanidin 3-galactoside (cy3-gal, fructose, sucrose, glucose and malic acid were the primary organic compounds, and 1-butanol-2-methyl-acetate, 2-hexenal and 1-hexanol were the most abundant aroma components in the skin. Furthermore, rapidly changing soluble sugars and organic acid synchronization took place in the early ripening period, while rapidly changing aroma components occurred later, on the basis of fresh weight. This result suggested that the production of aroma components might be a useful index of apple maturity.

Photocatalytic Activity and Characterization of Carbon-Modified Titania for Visible-Light-Active Photodegradation of Nitrogen Oxides

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Chun-Hung Huang

2012-01-01

Full Text Available A variety of carbon-modified titania powders were prepared by impregnation method using a commercial available titania powder, Hombikat UV100, as matrix material while a range of alcohols from propanol to hexanol were used as precursors of carbon sources. Rising the carbon number of alcoholic precursor molecule, the modified titania showed increasing visible activities of NOx photodegradation. The catalyst modified with cyclohexanol exhibited the best activities of 62%, 62%, 59%, and 54% for the total NOx removal under UV, blue, green, and red light irradiation, respectively. The high activity with long wavelength irradiation suggested a good capability of photocatalysis in full visible light spectrum. Analysis of UV-visible spectrum indicated that carbon modification promoted visible light absorption and red shift in band gap. XPS spectroscopic analysis identified the existence of carbonate species (C=O, which increased with the increasing carbon number of precursor molecule. Photoluminescence spectra demonstrated that the carbonate species suppressed the recombination rate of electron-hole pair. As a result, a mechanism of visible-light-active photocatalyst was proposed according to the formation of carbonate species on carbon-modified TiO2.

Structural and phase transition changes of sodium dodecyl sulfate micellar solution in alcohols probed by small-angle neutron scattering (SANS)

International Nuclear Information System (INIS)

Putra, Edy Giri Rachman; Patriati, Arum

2015-01-01

Small-angle neutron scattering (SANS) measurements on 0.3M sodium dodecyl sulfate (SDS) micellar solutions have been performed in the presence of n-alcohols, from ethanol to decanol at different alcohol concentrations, 2–10 wt%. The ellipsoid micellar structure which occurred in the 0.3M SDS in aqueous solution with the size range of 30–50 Å has different behavior at various hydrocarbon chain length and concentration of alcohols. At low concentration and short chain-length of alcohols, such as ethanol, propanol, and butanol, the size of micelles reduced and had a spherical-like structure. The opposite effect occurred as medium to long chain alcohols, such as hexanol, octanol and decanol was added into the 0.3M SDS micellar solutions. The micelles structure changed to be more elongated in major axis and then crossed the critical phase transition from micellar solution into liquid crystal phase as lamellar structure emerged by further addition of alcohols. The inter-lamellar distances were also depending on the hydrocarbon chain length and concentration of alcohols. In the meantime, the persistent micellar structures occurred in addition of medium chain of n-alcohol, pentanol at all concentrations

Characterization and extraction of volatile compounds from pineapple (Ananas comosus L. Merril processing residues

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Lília Calheiros de Oliveira Barretto

2013-12-01

Full Text Available The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%, followed by ketones (26%, alcohols (18%, aldehydes (9%, acids (3% and other compounds (9%. Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.

Detailed kinetic modeling study of n-pentanol oxidation

KAUST Repository

Heufer, Karl Alexander

2012-10-18

To help overcome the world\\'s dependence upon fossil fuels, suitable biofuels are promising alternatives that can be used in the transportation sector. Recent research on internal combustion engines shows that short alcoholic fuels (e.g., ethanol or n-butanol) have reduced pollutant emissions and increased knock resistance compared to fossil fuels. Although higher molecular weight alcohols (e.g., n-pentanol and n-hexanol) exhibit higher reactivity that lowers their knock resistance, they are suitable for diesel engines or advanced engine concepts, such as homogeneous charge compression ignition (HCCI), where higher reactivity at lower temperatures is necessary for engine operation. The present study presents a detailed kinetic model for n-pentanol based on modeling rules previously presented for n-butanol. This approach was initially validated using quantum chemistry calculations to verify the most stable n-pentanol conformation and to obtain C-H and C-C bond dissociation energies. The proposed model has been validated against ignition delay time data, speciation data from a jet-stirred reactor, and laminar flame velocity measurements. Overall, the model shows good agreement with the experiments and permits a detailed discussion of the differences between alcohols and alkanes. © 2012 American Chemical Society.

EFECTO DE LA TEMPERATURA SOBRE LAS PROPIEDADES VOLUMÉTRICAS DE ALCOHOLES ALIFÁTICOS EN SOLUCIONES ACUOSAS DILUIDAS.

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Carmen M. Romero

2009-05-01

Full Text Available La influencia de la temperatura sobre las propiedades volumétricas de soluciones acuosas ha sido frecuentemente usada para obtener información sobre los efectos de los distintos solutos sobre la estructura del agua.En este trabajo se presentan los resultados experimentales de densidades de soluciones acuosas diluidas de n-pentanol, n-hexanol, n-heptanol y n-octanol a 288,15; 293,15; 298,15; 303,15 y 308,15 K. Las medidas de densidad fueron realizadas en un densímetro Antón Paar de tubo vibracional (DMA 60/602 y a partir de los datos obtenidos se calcularon volúmenes de exceso, volúmenes molares aparentes y volúmenes molares parciales a dilución infinita. Para determinar el carácter hidrofóbico de los solutos empleados y su efecto sobre la estructura del agua se empleó el criterio de la segunda derivada del volumen molar parcial en función de la temperatura. Se calculó la contribución volumétrica del grupo CH2 encontrándose que tiene un valor constante en el rango de temperatura, estudiado.

In-tube extraction for the determination of the main volatile compounds in Physalis peruviana L.

Science.gov (United States)

Kupska, Magdalena; Jeleń, Henryk H

2017-01-01

An analytical procedure based on in-tube extraction followed by gas chromatography with mass spectrometry has been developed for the analysis of 24 of the main volatile components in cape gooseberry (Physalis peruviana L.) samples. According to their chemical structure, the compounds were organized into different groups: one hydrocarbon, one aldehyde, four alcohols, four esters, and 14 monoterpenes. By single-factor experiments, incubation temperature, incubation time, extraction volume, extraction strokes, extraction speed, desorption temperature, and desorption speed were determined as 60°C, 20 min, 1000 μL, 20, 50:50 μL/s, 280°C, 100 μL/s, respectively. Quantitative analysis using authentic standards and external calibration curves was performed. The limit of detection and limit of quantification for the analytical procedure were calculated. Results shown the benzaldehyde, ethyl butanoate, 2-methyl-1-butanol, 1-hexanol, 1-butanol, α-terpineol, and terpinen-4-ol were the most abundant volatile compounds in analyzed fruits (68.6-585 μg/kg). The obtained data may contribute to qualify cape gooseberry to the group of superfruits and, therefore, increase its popularity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

EKSTRAKSI ASAM SITRAT DAN ASAM OKSALAT : PENGARUH TRIOCTYLAMINE SEBAGAI EXTRACTING POWER DALAM BERBAGAI SOLVEN CAMPURAN TERHADAP KOEFISIEN DISTRIBUSI

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Mega Kasmiyatun

2012-01-01

Full Text Available Generally, liquid waste of citric acid industry containing a highly citric acid, oxalic acid, due to precipitation process of calcium citrate less completely. Liquid-liquid extraction process is this one alternative that used to recover citric acid and oxalic acid, either in the product separation process from the fermentor or the treatment of its liquid waste. In order to understand, that the extraction process can be applied both technically and economically, it needs a more study the extraction parameters. The investigation has carried out about study of the extraction of citric acid and oxalic acid used trioctyl-amine as extracting power on various mix solvent and its ratio, related to the distribution coefficient. Extraction used a separating funnel that it was shaked with using an automatic shaker, which adjusted on specific velocity during 2.5 hours. The rafinate and extract were separated by separating funnel, then they were analyzed both concentration of citric acid and oxalic acid using a high performance liquid chromatography (HPLC. The results of the research show that the mixed solvent (consist of 15% trioctyl amine, 70% dodecane, and 15% hexanol, for the extraction of citric acid  produce both the highest distribution coefficient and percentage of separation were 1.15 and 74.22%, respectively; and this were achieved for the ratio between the solvent and diluent of 2.5:1. For the extraction of oxalic acid similar result were obtained, and the value were 3.78 and 88.31%, respectively, for the ratio between solvent and diluent of 2:1.Limbah cair pabrik asam sitrat pada umumnya mengandung asam sitrat, asam oksalat, cukup tinggi akibat proses pengendapan calsium sitrat yang kurang sempurna. Proses ekstraksi cair-cair adalah salah satu alternatif yang dapat digunakan untuk pengambilan kembali asam sitrat dan asam oksalat, baik pada proses pemisahan produk yang keluar dari fermentor maupun pada proses pengolahan limbah cairnya. Untuk

Caracterização e extração de compostos voláteis de resíduos do processamento de maracujá (Passiflora edulis Sims f. flavicarpa degener Characterization and extraction of volatile compounds from passion fruit (Passiflora edulis Sims f. flavicarpa degener processing waste

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Lília Calheiros de Oliveira

2012-12-01

Full Text Available Este estudo objetivou extrair e identificar compostos voláteis presentes nos resíduos de processo de maracujá. Obtiveram-se destilados a partir de resíduos de maracujá através das técnicas de hidrodestilação simples e hidrodestilação com arraste de gás nitrogênio. Os compostos voláteis presentes nos destilados foram capturados por microextração em fase sólida, empregando-se fibra Carboxen/DVB/DMS, e identificados por cromatografia gasosa acoplada com espectrômetro de massa, usando a coluna capilar de sílica fundida CP WAX 52. Foram identificados trinta e um compostos voláteis no extrato obtido pela técnica de hidrodestilação simples, sendo os principais compostos: neral (26,19%, cinamato de metila (18,52%, linalol (16,82%, 1-undecanol (5,60%, cis-óxido de linalol (4,41%, benzaldeído (3,92% e 1-hexanol (3,48%. Para a hidrodestilação com arraste de gás nitrogênio, trinta compostos foram identificados, sendo que, em maior porcentagem de área, destacaram-se: cinamato de metila (30,41%, neral (24,46%, β-ionona (13,81%, linalol (4,0% e acido butanoico (2,19%. O presente estudo revelou que os resíduos de maracujá apresentam compostos voláteis que podem ser extraídos na forma de aromas, apresentando potencial para gerar essências naturais com valor agregado.The aim of this study was to extract and identify volatile compounds from passion fruit residues generated during processing. Distillates of passion fruit residues were obtained from the techniques of simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by solid phase microextraction with Carboxen/DVB/DMS fiber. The volatile compounds were indentified by gas chromatography with mass spectrometry using a fused sillica capillary column with a CP WAX 52 stationary phase. Thirty one compounds were indentified by simple hydrodistillation technique. The main compounds were: neral (26

Comparison of male and female emerald ash borer (Coleoptera: Buprestidae) responses to phoebe oil and (Z)-3-hexanol lures in light green prism traps

Science.gov (United States)

Gary G. Grant; Therese M. Poland; Tina Ciaramitaro; D. Barry Lyons; Gene C. Jones

2011-01-01

We conducted trapping experiments for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Michigan, USA, and Ontario, Canada, to compare unbaited light green sticky prism traps with traps baited with phoebe oil, (Z)-3-hexenol (Z3-6:OH), or blends of other green leaf volatiles (GLVs) with Z3-6:OH. Traps were placed in the...

Characterization of leaves and flowers volatile constituents of Lantana camara growing in central region of Saudi Ar

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Merajuddin Khan

2016-11-01

Full Text Available The chemical components of essential oils derived from leaves and flowers of Lantana camara growing in Saudi Arabia are analyzed for the first time using gas chromatography techniques (GC–MS, GC–FID, Co-GC, LRI determination, and database and literature searches on two different stationary phase columns (polar and nonpolar. This analysis led to the identification of total 163 compounds from leaves and flowers oils. 134 compounds were identified in the oil obtained from leaves of L. camara, whereas 127 compounds were identified in the oil obtained from flowers; these compounds account for 96.3% and 95.3% of the oil composition, respectively. The major components in the oil from leaves were cis-3-hexen-1-ol (11.3%, 1-octen-3-ol (8.7%, spathulenol (8.6%, caryophyllene oxide (7.5% and 1-hexanol (5.8%. In contrast, the major compounds in the flowers oil were caryophyllene oxide (10.6%, β-caryophyllene (9.7%, spathulenol (8.6%, γ-cadinene (5.6% and trans-β-farnesene (5.0%. To the best of our knowledge, cis-3-hexen-1-ol and 1-octen-3-ol that were identified as major components in this study have not been reported earlier from Lantana oils.

Phase equilibrium study of the binary systems (N-hexyl-3-methylpyridinium tosylate ionic liquid + water, or organic solvent)

International Nuclear Information System (INIS)

Domanska, Urszula; Krolikowski, Marek

2011-01-01

Highlights: → Synthesis, DSC, and measurements of phase equilibrium of N-hexyl-3-methylpyridinium tosylate. → Solvents used: water, alcohols, benzene, alkylbenzenes, and aliphatic hydrocarbons. → Correlation with UNIQUAC, Wilson and NRTL models. → Comparison with different tosylate-based ILs. - Abstract: The (solid + liquid) phase equilibrium (SLE) and (liquid + liquid) phase equilibrium (LLE) for the binary systems ionic liquid (IL) N-hexyl-3-methylpyridinium tosylate (p-toluenesulfonate), {([HM 3 Py][TOS] + water, or an alcohol (1-butanol, or 1-hexanol, or 1-octanol, or 1-decanol), or an aromatic hydrocarbon (benzene, toluene, or ethylbenzene, or propylbenzene), or an alkane (n-hexane, n-heptane, n-octane)} have been determined at ambient pressure using a dynamic method. Simple eutectic systems with complete miscibility in the liquid phase were observed for the systems involving water and alcohols. The phase equilibrium diagrams of IL and aromatic or aliphatic hydrocarbons exhibit eutectic systems with immiscibility in the liquid phase with an upper critical solution temperature as for most of the ILs. The correlation of the experimental data has been carried out using the UNIQUAC, Wilson and the non-random two liquid (NRTL) correlation equations. The results reported here have been compared with analogous phase diagrams reported by our group previously for systems containing the tosylate-based ILs.

Physico-chemical properties and sensory profile of durum wheat Dittaino PDO (Protected Designation of Origin) bread and quality of re-milled semolina used for its production.

Science.gov (United States)

Giannone, Virgilio; Giarnetti, Mariagrazia; Spina, Alfio; Todaro, Aldo; Pecorino, Biagio; Summo, Carmine; Caponio, Francesco; Paradiso, Vito Michele; Pasqualone, Antonella

2018-02-15

To help future quality checks, we characterized the physico-chemical and sensory properties of Dittaino bread, a sourdough-based durum wheat bread recently awarded with Protected Designation of Origin mark, along with the quality features of re-milled semolina used for its production. Semolina was checked for Falling Number (533-644s), protein content (12.0-12.3g/100gd.m.), gluten content (9.7-10.5g/100gd.m.), yellow index (18.0-21.0), water absorption (59.3-62.3g/100g), farinograph dough stability (171-327s), softening index (46-66B.U.), alveograph W (193×10 -4 -223×10 -4 J) and P/L (2.2-2.7). Accordingly, bread crumb was yellow, moderately hard (16.4-27.1N) and chewy (88.2-109.2N×mm), with low specific volume (2.28-3.03mL/g). Bread aroma profile showed ethanol and acetic acid, followed by hexanol, 3-methyl-1-butanol, 2-phenylethanol, 3-methylbutanal, hexanal, benzaldehyde, and furfural. The sensory features were dominated by a thick brown crust, with marked toasted odor, coupled to yellow and consistent crumb, with coarse grain and well-perceivable sour taste and odor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impedimetric PSA aptasensor based on the use of a glassy carbon electrode modified with titanium oxide nanoparticles and silk fibroin nanofibers.

Science.gov (United States)

Benvidi, Ali; Banaei, Maryam; Tezerjani, Marzieh Dehghan; Molahosseini, Hosein; Jahanbani, Shahriar

2017-12-14

This article describes an impedimetric aptasensor for the prostate specific antigen (PSA), a widely accepted prostate cancer biomarker. A glassy carbon electrode (GCE) was modified with titanium oxide nanoparticles (TiO 2 ) and silk fibroin nanofiber (SF) composite. The aptasensor was obtained by immobilizing a PSA-binding aptamer on the AuNP-modified with 6-mercapto-1-hexanol. The single fabrication steps were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The assay has two linear response ranges (from 2.5 fg.mL -1 to 25 pg.mL -1 , and from 25 pg.mL -1 to 25 ng.mL -1 ) and a 0.8 fg.mL -1 detection limit. After optimization of experimental conditions, the sensor is highly selective for PSA over bovine serum albumin and lysozyme. It was successfully applied to the detection of PSA in spiked serum samples. Graphical abstract Schematic of the fabrication of an aptasensor for the prostate specific antigen (PSA). It is based on the use of a glassy carbon electrode modified with gold nanoparticles and titanium oxide-silk fibroin. The immobilization process of aptamer and interaction with PSA were followed by electrochemical impedance spectroscopy technique.

Recovery of actinides from TBP-Na2Co3 scrub-waste solutions: the ARALEX process

International Nuclear Information System (INIS)

Horwitz, E.P.; Bloomquist, C.A.A.; Mason, G.W.; Leonard, R.A.; Ziegler, A.A.

1979-08-01

A flowsheet for the recovery of actinides from TBP-Na 2 CO 3 scrub-waste solutions has been developed, based on batch extraction data, and tested, using laboratory-scale countercurrent extraction techniques. The process, called the ARALEX process, uses 2-ethyl-1-hexanol (2-EHOH) to extract the TBP degradation products (HDBP and H 2 MBP) from acidified Na 2 CO 3 scrub waste leaving the actinides in the aqueous phase. Dibutyl and monobutyl phosphoric acids are attached to the 2-EHOH molecules through hydrogen bonds, which also diminish the ability of the HDBP and H 2 MBP to complex actinides. Thus all actinides remain in the aqueous raffinate. Dilute sodium hydroxide solutions can be used to back-extract the dibutyl and monobutyl phosphoric acid esters as their sodium salts. The 2-EHOH can then be recycled. After extraction of the acidified carbonate waste with 2-EHOH, the actinides may be readily extracted from the raffinate with DHDECMP or, in the case of tetra- and hexavalent actinides, with TBP. The ARALEX process can also be applied to other actinide waste streams which contain appreciable concentrations of polar organic compounds (e.g., detergents) that interfere with conventional actinide ion exchange and liquid-liquid extraction procedures. 20 figures, 6 tables

Acute poisoning with emamectin benzoate.

Science.gov (United States)

Yen, Tzung-Hai; Lin, Ja-Liang

2004-01-01

Emamectin benzoate is the 4'-deoxy-4'-epi-methyl-amino benzoate salt of avermectin B1 (abamectin), which is similar structurally to natural fermentation products of Streptomyces avermitilis. Emamectin benzoate is being developed as a newer broad-spectrum insecticide for vegetables and has a very low application rate. The mechanism of action involves stimulation of high-affinity GABA receptors and a consequent increase in membrane chloride ion permeability. Animal studies indicate a wide margin of safety because mammalian species are much less sensitive due to lower GABA receptor affinities and relative impermeability of the blood-brain barrier. Notably, the literature has not reported human exposure resulting in toxicity. This paper describes a case of acute poisoning with Proclaim insecticide (Syngenta, Taiwan), consisting of 2.15% w/w emamectin benzoate in 2, 6-bis (1, 1-dimethylethyl)-4-methyl-phenol and 1-hexanol. The clinical manifestation was transient gastrointestinal upset with endoscopy-proven gastric erosion and superficial gastritis, mild central nervous system depression, and aspiration pneumonia. No specific antidote exists for emamectin benzoate intoxication; this patient was treated successfully with gastric lavage, administration of activated charcoal, and empiric antibiotics. Drugs that enhance GABA activity such as barbiturates and benzodiazepines were avoided.

Flavor profiles of monovarietal virgin olive oils produced in the Oriental region of Morocco

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Mansouri Farid

2017-09-01

Full Text Available The purpose of this study is the evaluation of flavor profiles of monovarietal virgin olive oils (VOO produced in the Oriental region of Morocco via the characterization of volatile compounds, using SPME-GC/MS technique, and the determination of total phenolic content (colorimetric method. The study concerns oils of three European olive cultivars (Arbosana, Arbequina and Koroneiki which were recently introduced in Morocco under irrigated high-density plantation system. GC/MS aroma profiles of analyzed VOOs showed the presence of 35 volatile compounds. The major compounds in such oils are C6 compounds produced from linoleic and linolenic acids via lipoxygenase pathway such as trans-2-hexenal, cis-2-hexenal, cis-3-hexen-1-ol, trans-3-hexen-1-ol, trans-3-hexen-1-ol acetate, hexanal and 1-hexanol in different proportions depending on the cultivar (p < 0.05. In addition, statistical analyses indicate that the analyzed VOOs have different aroma profiles. Arbequina oil has a high proportion of compounds with sensory notes “green” and “sweet” giving it a fruity sensation compared to Arbosana and Koroneiki. In parallel, Arbosana and Koroneiki oils are rich in phenolic compounds and provide relatively bitter and pungent tastes to these oils.

Determining the thickness of aliphatic alcohol monolayers covalently attached to silicon oxide surfaces using angle-resolved X-ray photoelectron spectroscopy

Science.gov (United States)

Lee, Austin W. H.; Kim, Dongho; Gates, Byron D.

2018-04-01

The thickness of alcohol based monolayers on silicon oxide surfaces were investigated using angle-resolved X-ray photoelectron spectroscopy (ARXPS). Advantages of using alcohols as building blocks for the formation of monolayers include their widespread availability, ease of handling, and stability against side reactions. Recent progress in microwave assisted reactions demonstrated the ease of forming uniform monolayers with alcohol based reagents. The studies shown herein provide a detailed investigation of the thickness of monolayers prepared from a series of aliphatic alcohols of different chain lengths. Monolayers of 1-butanol, 1-hexanol, 1-octanol, 1-decanol, and 1-dodecanol were each successfully formed through microwave assisted reactions and characterized by ARXPS techniques. The thickness of these monolayers consistently increased by ∼1.0 Å for every additional methylene (CH2) within the hydrocarbon chain of the reagents. Tilt angles of the molecules covalently attached to silicon oxide surfaces were estimated to be ∼35° for each type of reagent. These results were consistent with the observations reported for thiol based or silane based monolayers on either gold or silicon oxide surfaces, respectively. The results of this study also suggest that the alcohol based monolayers are uniform at a molecular level.

Microemulsion based approach for nanospheres assembly into anisotropic nanostructures of NiMnO3 and their magnetic properties

Science.gov (United States)

Jha, Menaka; Kumar, Sandeep; Garg, Neha; Ramanujachary, Kandalam V.; Lofland, Samuel E.; Ganguli, Ashok K.

2018-02-01

The present study focuses on synthesis of anisotropic nanostructures of nickel manganese oxide (NiMnO3) obtained by thermal decomposition of nanocrystalline nickel manganese oxalate precursor, Ni0.5Mn0.5(C2O4)·2H2O which crystallized as nanorods. The synthesis of the oxalate precursor has been carried out via microemulsion-mediated process with cationic and non-ionic surfactants. The microemulsion led to reverse micelles, and the film flexibility of the micelle in presence of non-ionic surfactant (Tergitol) was reduced by increasing the chain length of the co-surfactant (1-butanol, 1-hexanol and 1-octanol) which led to the increase in reaction rate and hence increase in the aspect ratio of the nickel manganese oxalate by up to four times. However, in the presence of cationic surfactant, highly uniform nickel manganese oxalate nanorods were obtained. Further, the decomposition of the oxalate precursor was optimized to maintain the anisotropy of the rods of ternary metal oxide (NiMnO3). An electron microscopy study showed that the rods were made up of an assembly of ultrafine nanospheres. The NiMnO3 nanostructures were all ferrimagnetic with Curie temperature ranging between 437 and 467 K showing increasing saturation magnetization with increase in aspect ratio of the nanorods.

Effect of Raw Material, Pressing and Glycosidase on the Volatile Compound Composition of Wine Made From Goji Berries

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Guanshen Yuan

2016-10-01

Full Text Available This study investigated the effect of raw material, pressing, and glycosidase on the aromatic profile of goji berry wine. The free-run and the pressed juice of dried and fresh goji berries were used for wine production, whereas glycosidase was applied to wine after fermentation. Dried goji berry fermented wine exhibited much stronger fruity, floral, caramel, and herbaceous odors due to higher levels of esters, β-ionone and methionol. However, fresh berry fermented wine possessed stronger chemical notes due to higher levels of 4-ethylphenol. Pressing treatment reduced the fruity and caramel odors in these fermented wines, and fresh berry free-run juice fermented wine exhibited the least floral aroma. Glycosidase addition did not alter the aromatic composition of wines. The principal component analysis indicated that goji raw material played a primary role in differentiating the aromatic profiles of the wines due to the difference on the content of 20 esters, nine benzenes, eight aldehydes/ketones, three acids, two alcohols and six other volatiles. The content differences on isopentyl alcohol, styrene, benzyl alcohol, 1-octanol, (E-5-decen-1-ol, 1-hexanol, and β-cyclocitral resulted in the segregation of the wines with and without the pressing treatment, especially for fresh berry fermented wine.

VOCs monitoring of new materials for ceramic tiles decoration: GC–MS analysis of emissions from common vehicles and inkjet inks during firing in laboratory

International Nuclear Information System (INIS)

Ferrari, G.; Zannini, P.

2017-01-01

The decoration of ceramic tiles “ink-jet revolution” has brought significant advantages to tiles manufacturing, but the explosive diffusion, until 4–5 years ago, of this technique has not been accomplished by an adequate scientific research. Among all the features that have to be studied yet, one of the most important is the influence of the new generation inks on the total emission at ceramic chimneys. In this paper, we present a first characterization of emissions from a set of commercial inks and vehicles: they were collected by propter firing of samples in an electric kiln and analyzed by GC–MS. This study is part of a larger research project, which includes the chemical characterization and the evaluation of thermal behavior of inks and vehicles by TG-DTA and other techniques. The obtained results permit to divide common vehicles into 3 classes, depending on their thermal behavior and emissions pattern. Inks, most of which present an ester based formulation, sometimes mixed with glycols or paraffins, follow the behavior of their single components. The most common formulation leads to the presence in the emission pattern of evaporation products (2-ethylhexyl esters of lauric, myristic, decanoic and octanoic acids) and decomposition products (mainly aldehydes and 2-ethyl-1-hexanol). [es

VOCs monitoring of new materials for ceramic tiles decoration: GC–MS analysis of emissions from common vehicles and inkjet inks during firing in laboratory

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Giorgia Ferrari

2017-09-01

Full Text Available The decoration of ceramic tiles “ink-jet revolution” has brought significant advantages to tiles manufacturing, but the explosive diffusion, until 4–5 years ago, of this technique has not been accomplished by an adequate scientific research. Among all the features that have to be studied yet, one of the most important is the influence of the new generation inks on the total emission at ceramic chimneys. In this paper, we present a first characterization of emissions from a set of commercial inks and vehicles: they were collected by propter firing of samples in an electric kiln and analyzed by GC–MS. This study is part of a larger research project, which includes the chemical characterization and the evaluation of thermal behavior of inks and vehicles by TG-DTA and other techniques. The obtained results permit to divide common vehicles into 3 classes, depending on their thermal behavior and emissions pattern. Inks, most of which present an ester based formulation, sometimes mixed with glycols or paraffins, follow the behavior of their single components. The most common formulation leads to the presence in the emission pattern of evaporation products (2-ethylhexyl esters of lauric, myristic, decanoic and octanoic acids and decomposition products (mainly aldehydes and 2-ethyl-1-hexanol.

(Semi)volatile organic compounds and microbiological entities in snow during OASIS Barrow 2009

Science.gov (United States)

Ariya, P.; Kos, G.

2009-12-01

Gregor Kos (1), Nafissa Adechina (2), Dwayne Lutchmann (2) , Roya Mortazavi, and Parisa Ariya* (1), (2) (1) McGill University, Department of Atmospheric and Oceanic Sciences, 805 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada (2) McGill University, Department of Chemistry, 801 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada an active medium for the deposition of (semi-)volatile (bio)organic compounds. We collected surface snow samples during the OASIS Barrow campaign in March 2009 for analysis of semi-volatile organic compounds using solid phase microextraction and gas chromatography with mass spectrometric detection (SPME-GC/MS). Additioal gab samples were taken for analysis of non-methane hydrocarbons in air. More over, we analyzed for microbial species in air and snow. Identifed organic compounds covered a wide range of functionalities andmolecular weigts, including oxygenated reactive speces such as aldehydes (e.g., hexanal to decanal), alcohols (e.g., hexanol, octanol) and aromatic species (e.g., methyl- and ethylbenzenes). Quantification data for selected aromatic species are presented with concentrations in the upper ng/L range. We will present our preliminary data on microbiological species, and will discuss the potential mplications of the results for organic snow chemistry.

New active HIV-1 protease inhibitors derived from 3-hexanol: conformation study of the free inhibitors in crystalline state and in complex with the enzyme

Czech Academy of Sciences Publication Activity Database

Ziólkowska, N. E.; Bujacz, A.; Randad, R. S.; Erickson, J. W.; Skálová, Tereza; Hašek, Jindřich; Bujacz, G.

2012-01-01

Roč. 79, č. 5 (2012), s. 798-809 ISSN 1747-0277 R&D Projects: GA ČR GA305/07/1073; GA AV ČR IAA500500701 Institutional research plan: CEZ:AV0Z40500505 Keywords : acquired immunodeficiency syndrome * crystal structure * drug design Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.469, year: 2012

Study of the volatile compounds from plum (Prunus domestica L. cv. Horvin and estimation of their contribution to the fruit aroma Estudo de compostos voláteis de ameixa (Prunus domestica L. cv. Horvin e estimativa da sua contribuição ao aroma

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Jorge Antonio Pino

2012-03-01

Full Text Available Simultaneous Distillation-Extraction (SDE and headspace-solid phase microextraction (HS-SPME combined with GC-FID and GC-MS were used to analyze volatile compounds from plum (Prunus domestica L. cv. Horvin and to estimate the most odor-active compounds by application of the Odor Activity Values (OAV. The analyses led to the identification of 148 components, including 58 esters, 23 terpenoids, 14 aldehydes, 11 alcohols, 10 ketones, 9 alkanes, 7 acids, 4 lactones, 3 phenols, and other 9 compounds of different structures. According to the results of SDE-GC-MS, SPME-GC-MS and OAV, ethyl 2-methylbutanoate, hexyl acetate, (E-2-nonenal, ethyl butanoate, (E-2-decenal, ethyl hexanoate, nonanal, decanal, (E-β-ionone, Γ-dodecalactone, (Z-3-hexenyl acetate, pentyl acetate, linalool, Γ-decalactone, butyl acetate, limonene, propyl acetate, Δ-decalactone, diethyl sulfide, (E-2-hexenyl acetate, ethyl heptanoate, (Z-3-hexenol, (Z-3-hexenyl hexanoate, eugenol, (E-2-hexenal, ethyl pentanoate, hexyl 2-methylbutanoate, isopentyl hexanoate, 1-hexanol, Γ-nonalactone, myrcene, octyl acetate, phenylacetaldehyde, 1-butanol, isobutyl acetate, (E-2-heptenal, octadecanal, and nerol are characteristic odor active compounds in fresh plums since they showed concentrations far above their odor thresholds.As técnicas de extração-destilação simultâneas (SDE e de headspace-microextração em fase sólida (HS-SPME combinadas com GC-FID e GC-MS foram usadas para analisar compostos voláteis da ameixa (Prunus domestica L. cv. Horvin e para estimar os compostos de aroma mais ativos, pela aplicação de valores de atividade olfativa (OAV, considerando os compostos voláteis presentes no headspace da fruta. As análises levaram à identificação de 148 componentes, incluindo 58 ésteres, 23 terpenoides, 14 aldeídos, 11 álcoois, 10 cetonas, 9 alcanos, 7 ácidos, 4 lactonas, 3 fenóis e 9 outros compostos de diferentes estruturas. De acordo om os resultados de SDE

VOCs monitoring of new materials for ceramic tiles decoration: GC–MS analysis of emissions from common vehicles and inkjet inks during firing in laboratory; Monitorización de los COV de nuevos materiales para la decoración de azulejos cerámicos: análisis con GC-MS de las emisiones de vehículos comunes y de tintas digitales durante la cocción en laboratorio

Energy Technology Data Exchange (ETDEWEB)

Ferrari, G.; Zannini, P.

2017-11-01

The decoration of ceramic tiles “ink-jet revolution” has brought significant advantages to tiles manufacturing, but the explosive diffusion, until 4–5 years ago, of this technique has not been accomplished by an adequate scientific research. Among all the features that have to be studied yet, one of the most important is the influence of the new generation inks on the total emission at ceramic chimneys. In this paper, we present a first characterization of emissions from a set of commercial inks and vehicles: they were collected by propter firing of samples in an electric kiln and analyzed by GC–MS. This study is part of a larger research project, which includes the chemical characterization and the evaluation of thermal behavior of inks and vehicles by TG-DTA and other techniques. The obtained results permit to divide common vehicles into 3 classes, depending on their thermal behavior and emissions pattern. Inks, most of which present an ester based formulation, sometimes mixed with glycols or paraffins, follow the behavior of their single components. The most common formulation leads to the presence in the emission pattern of evaporation products (2-ethylhexyl esters of lauric, myristic, decanoic and octanoic acids) and decomposition products (mainly aldehydes and 2-ethyl-1-hexanol). [Spanish] La decoración de los azulejos cerámicos mediante tecnología Ink-jet ha supuesto numerosas ventajas en la producción de baldosas cerámicas, pero su rápida implantación no ha sido acompañada por una adecuada investigación científica, hasta hace 4–5 años. Entre todas las características que deberían ser estudiadas, una de las más importantes es la influencia de las nuevas tintas digitales en las emisiones totales de las chimeneas cerámicas. En este artículo presentamos una primera caracterización de las emisiones de un grupo de tintas y vehículos comerciales: las emisiones se recogieron durante la cocción en laboratorio y fueron analizadas por GC

A Facile Droplet-Chip-Time-Resolved Inductively Coupled Plasma Mass Spectrometry Online System for Determination of Zinc in Single Cell.

Science.gov (United States)

Wang, Han; Chen, Beibei; He, Man; Hu, Bin

2017-05-02

Single cell analysis is a significant research field in recent years reflecting the heterogeneity of cells in a biological system. In this work, a facile droplet chip was fabricated and online combined with time-resolved inductively coupled plasma mass spectrometry (ICPMS) via a microflow nebulizer for the determination of zinc in single HepG2 cells. On the focusing geometric designed PDMS microfluidic chip, the aqueous cell suspension was ejected and divided by hexanol to generate droplets. The droplets encapsulated single cells remain intact during the transportation into ICP for subsequent detection. Under the optimized conditions, the frequency of droplet generation is 3-6 × 10 6 min -1 , and the injected cell number is 2500 min -1 , which can ensure the single cell encapsulation. ZnO nanoparticles (NPs) were used for the quantification of zinc in single cells, and the accuracy was validated by conventional acid digestion-ICPMS method. The ZnO NPs incubated HepG2 cells were analyzed as model samples, and the results exhibit the heterogeneity of HepG2 cells in the uptake/adsorption of ZnO NPs. The developed online droplet-chip-ICPMS analysis system achieves stable single cell encapsulation and has high throughput for single cell analysis. It has the potential in monitoring the content as well as distribution of trace elements/NPs at the single cell level.

Non-destructive profiling of volatile organic compounds using HS-SPME/GC-MS and its application for the geographical discrimination of white rice.

Science.gov (United States)

Lim, Dong Kyu; Mo, Changyeun; Lee, Dong-Kyu; Long, Nguyen Phuoc; Lim, Jongguk; Kwon, Sung Won

2018-01-01

The authenticity determination of white rice is crucial to prevent deceptive origin labeling and dishonest trading. However, a non-destructive and comprehensive method for rapidly discriminating the geographical origins of white rice between countries is still lacking. In the current study, we developed a volatile organic compound based geographical discrimination method using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME/GC-MS) to discriminate rice samples from Korea and China. A partial least squares discriminant analysis (PLS-DA) model exhibited a good classification of white rice between Korea and China (accuracy = 0.958, goodness of fit = 0.937, goodness of prediction = 0.831, and permutation test p-value = 0.043). Combining the PLS-DA based feature selection with the differentially expressed features from the unpaired t-test and significance analysis of microarrays, 12 discriminatory biomarkers were found. Among them, hexanal and 1-hexanol have been previously known to be associated with the cultivation environment and storage conditions. Other hydrocarbon biomarkers are novel, and their impact on rice production and storage remains to be elucidated. In conclusion, our findings highlight the ability to rapidly discriminate white rice from Korea and China. The developed method maybe useful for the authenticity and quality control of white rice. Copyright © 2017. Published by Elsevier B.V.

Non-destructive profiling of volatile organic compounds using HS-SPME/GC–MS and its application for the geographical discrimination of white rice

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Dong Kyu Lim

2018-01-01

Full Text Available The authenticity determination of white rice is crucial to prevent deceptive origin labeling and dishonest trading. However, a non-destructive and comprehensive method for rapidly discriminating the geographical origins of white rice between countries is still lacking. In the current study, we developed a volatile organic compound based geographical discrimination method using headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME/GC–MS to discriminate rice samples from Korea and China. A partial least squares discriminant analysis (PLS-DA model exhibited a good classification of white rice between Korea and China (accuracy = 0.958, goodness of fit = 0.937, goodness of prediction = 0.831, and permutation test p-value = 0.043. Combining the PLS-DA based feature selection with the differentially expressed features from the unpaired t-test and significance analysis of microarrays, 12 discriminatory biomarkers were found. Among them, hexanal and 1-hexanol have been previously known to be associated with the cultivation environment and storage conditions. Other hydrocarbon biomarkers are novel, and their impact on rice production and storage remains to be elucidated. In conclusion, our findings highlight the ability to rapidly discriminate white rice from Korea and China. The developed method maybe useful for the authenticity and quality control of white rice.

The effects of gamma irradiation on the volatile components of desiccated coconut during storage

International Nuclear Information System (INIS)

Acevedo, T.P.; Azanza, M.P.

1989-11-01

Flavor volatiles of desiccated and irradiated desiccated coconut stored for 24 weeks at room temperature were identified and quantified by gas chromatography. Chromatograms of fresh coconut meat revealed sone esters, ketones, aldehydes and alcohols which were responsible for its fruity odor. The oily odor of fresh coconut meat was attributed to minimal amount of delta lactones. Freshly desiccated coconut contained the same volatiles responsible for the fresh fruity odor but the concentration of the delta lactones was considerably higher. The newly irradiated desiccated coconut had the highest concentration of the delta lactones with other volatiles such as ethyl caproate, 1-hexanol, and caprylic aldehyde being also present. With storage, development of oily odor to rancid odor was noted due to increasing amount of delta lactones. Corresponding decrease of volatiles responsible for the fresh fruity odor was noted as shown by the chromatographic profiles of both irradiated and unirradiated samples. Odor deterioration was more pronounced in the irradiated sample. Significant changes in moisture content, peroxide and iodine values, and free acid were observed during storage. No significant changes, however were noted in percent oil, pH and water activity. Significant difference in color, taste and general acceptability were noted at the start of storage with odor changes becoming more evident only after 4 weeks of storage. (Auth.). 69 refs.; 15 figs.; 14 tabs.; Appendix p. 90-205

Chemical characterization of the aroma of Grenache rosé wines: aroma extract dilution analysis, quantitative determination, and sensory reconstitution studies.

Science.gov (United States)

Ferreira, Vicente; Ortín, Natalia; Escudero, Ana; López, Ricardo; Cacho, Juan

2002-07-03

The aroma of a Grenache rosé wine from Calatayud (Zaragoza, Spain) has been elucidated following a strategy consisting of an aroma extract dilution analysis (AEDA), followed by the quantitative analysis of the main odorants and the determination of odor activities values (OAVs) and, finally, by a series of reconstitution and omission tests with synthetic aroma models. Thirty-eight aroma compounds were found in the AEDA study, 35 of which were identified. Twenty-one compounds were at concentrations higher than their corresponding odor thresholds. An aroma model prepared by mixing the 24 compounds with OAV > 0.5 in a synthetic wine showed a high qualitative similarity with the aroma of the rosé wine. The addition of compounds with OAV 10 was very different from that of the wine. Omission tests revealed that the most important odorant of this Grenache rosé wine was 3-mercapto-1-hexanol, with a deep impact on the wine fruity and citric notes. The synergic action of Furaneol and homofuraneol also had an important impact on wine aroma, particularly in its fruity and caramel notes. The omission of beta-damascenone, which had the second highest OAV, caused only a slight decrease on the intensity of the aroma model. Still weaker was the sensory effect caused by the omission of 10 other compounds, such as fatty acids and their ethyl esters, isoamyl acetate, and higher alcohols.

Characterization of Cr/Bentonite and HZSM-5 Zeolite as Catalysts for Ethanol Conversion to Biogasoline

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Robert Ronal Widjaya

2012-04-01

Full Text Available In this research it has been done characterization on Cr/Bentonit and Zeolit HZSM-5 catalysts for ethanol catalytic process to biogasoline (equal to gasoline. Cr/Bentonit has high acidity and resistant to a lot of moisture, so in addition to being able to processing feed which a lot of moisture (>15% from ethanol-water mixture, also it is not easy deactivated. Cr/Bentonit which is then used as the catalyst material on the process of ethanol conversion to be biogasoline and the result was compared with catalyst HZSM-5 zeolite. Several characterization methods: X-ray diffraction, Brunauer Emmett Teller (BET, thermogravimetry analysis (TGA, and catalyst activity tests using catalytic Muffler instrument and gas chromatography-mass spectrometry (GC-MS for product analysis were performed on both catalysts. From acidity measurement, it is known that acidity level of Cr/Bentonit is the highest and also from XRD result, it is known there is shift for 2theta in Cr/Bentonit, which indicates that Cr-pillar in the Bentonite can have interaction. It is also supported by BET data that shows the addition of specific surface are in Cr/Bentonite compared with natural Bentonite before pillarization. Futhermore catalyst activity test produced the results, analyzed by GC-MS, identified as butanol and also possibly formed hexanol, decane, dodecane, undecane, which are all included in gasoline range (C4 until C12.

Lipophosphoramidate-based bipolar amphiphiles: their syntheses and transfection properties.

Science.gov (United States)

Berchel, Mathieu; Le Gall, Tony; Lozach, Olivier; Haelters, Jean-Pierre; Montier, Tristan; Jaffrès, Paul-Alain

2016-03-14

Six new cationic bolaamphiphiles (also called bipolar amphiphiles, bolaform amphiphiles, or bolalipids) were readily prepared by a thiol-ene click reaction that engaged a mercapto-alcohol (mercapto-ethanol or mercapto-hexanol) and a cationic based lipophosphoramidate. The cationic lipophosphoramidates contain two lipid chains that end in an alkene group and a selected cationic polar head group (trimethylammonium, dimethyl hydroxyethyl ammonium, or methylimidazolium). These compounds were formulated in water (with or without DOPE as a colipid) to produce supramolecular aggregates. These aggregates, before (i.e. bolasomes) and after (i.e. bolaplexes) mixing with plasmid DNA (pDNA) at various charge ratios, were characterized with regard to their sizes and zeta potentials. In the case of bolasomes, the suspensions were unstable since precipitation occurred after only a few hours at room temperature. On the other hand, bolaplex formulations exhibited clearly a better colloidal stability. Then, the gene delivery properties of the cationic bolasomes were investigated using two human-derived epithelial cell lines (A549 and 16HBE). Compared to the commercially available lipofection reagent (Lipofectamine), most of the cationic bolaamphiphiles were able to efficiently transfect these cells when they were formulated with DOPE in a 1 : 1 molar ratio. We report herein that bolaamphiphiles possessing a trimethylammonium or a dimethyl hydroxyethyl ammonium head group were the most efficient in terms of transfection efficiency while exhibiting no significant cytotoxicity.

Differential involvement of glutamate-gated chloride channel splice variants in the olfactory memory processes of the honeybee Apis mellifera.

Science.gov (United States)

Démares, Fabien; Drouard, Florian; Massou, Isabelle; Crattelet, Cindy; Lœuillet, Aurore; Bettiol, Célia; Raymond, Valérie; Armengaud, Catherine

2014-09-01

Glutamate-gated chloride channels (GluCl) belong to the cys-loop ligand-gated ion channel superfamily and their expression had been described in several invertebrate nervous systems. In the honeybee, a unique gene amel_glucl encodes two alternatively spliced subunits, Amel_GluCl A and Amel_GluCl B. The expression and differential localization of those variants in the honeybee brain had been previously reported. Here we characterized the involvement of each variant in olfactory learning and memory processes, using specific small-interfering RNA (siRNA) targeting each variant. Firstly, the efficacy of the two siRNAs to decrease their targets' expression was tested, both at mRNA and protein levels. The two proteins showed a decrease of their respective expression 24h after injection. Secondly, each siRNA was injected into the brain to test whether or not it affected olfactory memory by using a classical paradigm of conditioning the proboscis extension reflex (PER). Amel_GluCl A was found to be involved only in retrieval of 1-nonanol, whereas Amel_GluCl B was involved in the PER response to 2-hexanol used as a conditioned stimulus or as new odorant. Here for the first time, a differential behavioral involvement of two highly similar GluCl subunits has been characterized in an invertebrate species. Copyright © 2014 Elsevier Inc. All rights reserved.

Analysis of volatile organic compounds in pleural effusions by headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry.

Science.gov (United States)

Huang, Zhongping; Zhang, Jie; Zhang, Peipei; Wang, Hong; Pan, Zaifa; Wang, Lili

2016-07-01

Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box-plot analysis showed that except for cyclohexanone, 2-ethyl-1-hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n-heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlled synthesis of size-tunable nickel and nickel oxide nanoparticles using water-in-oil microemulsions

International Nuclear Information System (INIS)

Kumar, Ajeet; Saxena, Amit; Shankar, Ravi; Mozumdar, Subho; De, Arnab

2013-01-01

Industrial demands have generated a growing need to synthesize pure metal and metal–oxide nanoparticles of a desired size. We report a novel and convenient method for the synthesis of spherical, size tunable, well dispersed, stable nickel and nickel oxide nanoparticles by reduction of nickel nitrate at room temperature in a TX-100/n-hexanol/cyclohexane/water system by a reverse microemulsion route. We determined that reduction with alkaline sodium borohydrate in nitrogen atmosphere leads to the formation of nickel nanoparticles, while the use of hydrazine hydrate in aerobic conditions leads to the formation of nickel oxide nanoparticles. The influence of several reaction parameters on the size of nickel and nickel oxide nanoparticles were evaluated in detail. It was found that the size can be easily controlled either by changing the molar ratio of water to surfactant or by simply altering the concentration of the reducing agent. The morphology and structure of the nanoparticles were characterized by quasi-elastic light scattering (QELS), transmission electron microscopy (TEM), x-ray diffraction (XRD), electron diffraction analysis (EDA) and energy dispersive x-ray (EDX) spectroscopy. The results show that synthesized nanoparticles are of high purity and have an average size distribution of 5–100 nm. The nanoparticles prepared by our simple methodology have been successfully used for catalyzing various chemical reactions. (paper)

FLAVOR BIOGENERATION IN MANGABA (Hancornia speciosa Gomes FRUIT

Directory of Open Access Journals (Sweden)

Narenda Narain

2007-11-01

Full Text Available Most of the volatile flavoring substances are formed during maturation of fruit when it ripens. In this study, the mangaba (Hancornia speciosa Gomes fruit was harvested at half-ripe and ripe stages of maturity and analyzed for its volatile components. The extracts were obtained from the fruit pulp by using simultaneous distillation and extraction technique. Several extraction parameters such as weight of the pulp, dilution with water, solvent volume and extraction period were standardized to obtain highly characteristic fruit aroma extracts. The extracts were analyzed for the identification of volatile compounds by using a system of high resolution gas chromatograph coupled with mass spectrometer. Eighty-six components were separated out of which 46 compounds were positively identified. The volatile flavoring substances pertaining to classes of esters and terpenes increased from 6.19 to 35.487% and from 7.51 to 10.40%, respectively. The principal volatile compounds present in the pulp of ripe mangaba fruit were isopropyl acetate (19.23%, 3-hexanol (10.74%, linalool (7.38%, ä-limonene (2.43%, 3-pentanol (3.80%, 3-ethyl 2-buten-1-ol (2.53% and furfural (1.52%. Biogeneration of mangaba flavor is mainly characterized due to the presence of compounds pertaining to esters, aldehydes and terpenes.

Miscibility and interaction between 1-alkanol and short-chain phosphocholine in the adsorbed film and micelles.

Science.gov (United States)

Takajo, Yuichi; Matsuki, Hitoshi; Kaneshina, Shoji; Aratono, Makoto; Yamanaka, Michio

2007-09-01

The miscibility and interaction of 1-hexanol (C6OH) and 1-heptanol (C7OH) with 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) in the adsorbed films and micelles were investigated by measuring the surface tension of aqueous C6OH-DHPC and aqueous C7OH-DHPC solutions. The surface density, the mean molecular area, the composition of the adsorbed film, and the excess Gibbs energy of adsorption g(H,E), were estimated. Further, the critical micelle concentration of the mixtures was determined from the surface tension versus molality curves; the micellar composition was calculated. The miscibility of the 1-alkanols and DHPC molecules in the adsorbed film and micelles was examined using the phase diagram of adsorption (PDA) and that of micellization (PDM). The PDA and the composition dependence of g(H,E) indicated the non-ideal mixing of the 1-alkanols and DHPC molecules due to the attractive interaction between the molecules in the adsorbed film, while the PDM indicated that the 1-alkanol molecules were not incorporated in the micelles within DHPC rich region. The dependence of the mean molecular area of the mixtures on the surface composition suggested that the packing property of the adsorbed film depends on the chain length of 1-alkanol: C6OH expands the DHPC adsorbed film more than C7OH.

The influence of reagent type on the kinetics of ultrafine coal flotation

Science.gov (United States)

Read, R.B.; Camp, L.R.; Summers, M.S.; Rapp, D.M.

1989-01-01

A kinetic study has been conducted to determine the influence of reagent type on flotation rates of ultrafine coal. Two ultrafine coal samples, the Illinois No. 5 (Springfield) and Pittsburgh No. 8, have been evaluated with various reagent types in order to derive the rate constants for coal (kc), ash (ka), and pyrite (kc). The reagents used in the study include anionic surfactants, anionic surfactant-alcohol mixtures, and frothing alcohols. In general, the surfactant-alcohol mixtures tend to float ultrafine coal at a rate three to four times faster than either pure alcohols or pure anionic surfactants. Pine oil, a mixture of terpene alcohols and hydrocarbons, was an exception to this finding; it exhibited higher rate constants than the pure aliphatic alcohols or other pure anionic surfactants studied; this may be explained by the fact that the sample of pine oil used (70% alpha-terpineol) acted as a frother/collector system similar to alcohol/kerosene. The separation efficiencies of ash and pyrite from coal, as evidenced by the ratios of kc/ka or kc/kp, tend to indicate, however, that commercially available surfactant-alcohol mixtures are not as selective as pure alcohols such as 2-ethyl-1-hexanol or methylisobutylcarbinol. Some distinct differences in various rate constants, or their ratios, were noted between the two coals studied, and are possibly attributable to surface chemistry effects. ?? 1989.

Inhibition of Pseudogymnoascus destructans growth from conidia and mycelial extension by bacterially produced volatile organic compounds.

Science.gov (United States)

Cornelison, Christopher T; Gabriel, Kyle T; Barlament, Courtney; Crow, Sidney A

2014-02-01

The recently identified causative agent of white-nose syndrome (WNS), Pseudogymnoascus destructans, has been implicated in the mortality of an estimated 5.5 million North American bats since its initial documentation in 2006 (Frick et al. in Science 329:679-682, 2010). In an effort to identify potential biological and chemical control options for WNS, 6 previously described bacterially produced volatile organic compounds (VOCs) were screened for anti-P. destructans activity. The compounds include decanal; 2-ethyl-1-hexanol; nonanal; benzothiazole; benzaldehyde; andN,N-dimethyloctylamine. P. destructans conidia and mycelial plugs were exposed to the VOCs in a closed air space at 15 and 4 °C and then evaluated for growth inhibition. All VOCs inhibited growth from conidia as well as inhibiting radial mycelial extension, with the greatest effect at 4 °C. Studies of the ecology of fungistatic soils and the natural abundance of the fungistatic VOCs present in these environments suggest a synergistic activity of select VOCs may occur. The evaluation of formulations of two or three VOCs at equivalent concentrations was supportive of synergistic activity in several cases. The identification of bacterially produced VOCs with anti-P. destructans activity indicates disease-suppressive and fungistatic soils as a potentially significant reservoir of biological and chemical control options for WNS and provides wildlife management personnel with tools to combat this devastating disease.

Membrane fluidization by alcohols inhibits DesK-DesR signalling in Bacillus subtilis.

Science.gov (United States)

Vaňousová, Kateřina; Beranová, Jana; Fišer, Radovan; Jemioła-Rzemińska, Malgorzata; Matyska Lišková, Petra; Cybulski, Larisa; Strzałka, Kazimierz; Konopásek, Ivo

2018-03-01

After cold shock, the Bacillus subtilis desaturase Des introduces double bonds into the fatty acids of existing membrane phospholipids. The synthesis of Des is regulated exclusively by the two-component system DesK/DesR; DesK serves as a sensor of the state of the membrane and triggers Des synthesis after a decrease in membrane fluidity. The aim of our work is to investigate the biophysical changes in the membrane that are able to affect the DesK signalling state. Using linear alcohols (ethanol, propanol, butanol, hexanol, octanol) and benzyl alcohol, we were able to suppress Des synthesis after a temperature downshift. The changes in the biophysical properties of the membrane caused by alcohol addition were followed using membrane fluorescent probes and differential scanning calorimetry. We found that the membrane fluidization induced by alcohols was reflected in an increased hydration at the lipid-water interface. This is associated with a decrease in DesK activity. The addition of alcohol mimics a temperature increase, which can be measured isothermically by fluorescence anisotropy. The effect of alcohols on the membrane periphery is in line with the concept of the mechanism by which two hydrophilic motifs located at opposite ends of the transmembrane region of DesK, which work as a molecular caliper, sense temperature-dependent variations in membrane properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Study on emission of decomposed chemicals of esters contained in PVC flooring and adhesive

Energy Technology Data Exchange (ETDEWEB)

Chino, Satoko; Ataka, Yuji [R and D Center, Yoshino Gypsum Co., Ltd., 2-1-1 Kohoku, Adachi-ku, Tokyo, 123-0872 (Japan); Kato, Shinsuke; Seo, Janghoo [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

2009-07-15

2-Ethyl-1-hexanol (2E1H) is sometimes detected in indoor air at relatively high concentrations. The emission mechanism for 2E1H is considered to be that moisture with a high pH in concrete slabs and self-leveling sub-flooring material reacts with di-2-ethylhexyl phthalate (DEHP) in the polyvinyl chloride (PVC) flooring and compounds containing the 2-ethyl-1-hexyl group in the adhesive. 2E1H is considered to be one of the causes of odor in indoor air and sick building syndrome, so it is important to clarify the 2E1H emission mechanism for IAQ. However, there are few reports on any experimentation into 2E1H emission by chemical reaction involving building materials. In this study, PVC floorings are attached using various adhesives to a self-leveling sub-flooring material that contains water, and their 2E1H emission rates are measured. Furthermore, the components of the adhesives are determined using chemical analysis. It is found that 2E1H emission rates from the floor are affected by the type of adhesive used. On the other hand, some components in the adhesives may suppress the hydrolysis of esters. The hydrolysis of polymers and residual monomers in the adhesive causes 2E1H emission from the adhesive. (author)

Influence of microemulsion chirality on chromatographic figures of merit in EKC: results with novel three-chiral-component microemulsions and comparison with one- and two-chiral-component microemulsions.

Science.gov (United States)

Kahle, Kimberly A; Foley, Joe P

2007-08-01

Novel microemulsion formulations containing all chiral components are described for the enantioseparation of six pairs of pharmaceutical enantiomers (atenolol, ephedrine, metoprolol, N-methyl ephedrine, pseudoephedrine, and synephrine). The chiral surfactant dodecoxycarbonylvaline (DDCV, R- and S-), the chiral cosurfactant S-2-hexanol, and the chiral oil diethyl tartrate (R- and S-) were combined to create four different chiral microemulsions, three of which were stable. Results obtained for enantioselectivity, efficiency, and resolution were compared for the triple-chirality systems and the single-chirality system that contained chiral surfactant only. Improvements in enantioselectivity and resolution were achieved by simultaneously incorporating three chiral components into the aggregate. The one-chiral-component microemulsion provided better efficiencies. Enantioselective synergies were identified for the three-chiral-component nanodroplets using a thermodynamic model. Additionally, two types of dual-chirality systems, chiral surfactant/chiral cosurfactant and chiral surfactant/chiral oil, were examined in terms of chromatographic figures of merit, with the former providing much better resolution. The two varieties of two-chiral-component microemulsions gave similar values for enantioselectivity and efficiency. Lastly, the microemulsion formulations were divided into categories based on the number of chiral microemulsion reagents and the average results for each pair of enantiomers were analyzed for trends. In general, enantioselectivity and resolution were enhanced while efficiency was decreased as more chiral components were used to create the pseudostationary phase (PSP).

Volatile composition of Merlot red wine and its contribution to the aroma: optimization and validation of analytical method.

Science.gov (United States)

Arcari, Stefany Grützmann; Caliari, Vinicius; Sganzerla, Marla; Godoy, Helena Teixeira

2017-11-01

A methodology for the determination of volatile compounds in red wine using headspace solid phase microextraction (HS-SPME) combined with gas chromatography-ion trap/ mass spectrometry (GC-IT/MS) and flame ionization detector (GC -FID) was developed, validated and applied to a sample of Brazilian red wine. The optimization strategy was conducted using the Plackett-Burman design for variable selection and central composite rotational design (CCRD). The response surface methodology showed that the performance of the extraction of the volatile compounds using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber is improved with no sample dilution, the addition of 30% NaCl, applying an extraction temperature of 56°C and extraction time of 55min. The qualitative method allowed the extraction and identification of 60 volatile compounds in the sample studied, notably the classes of esters, alcohols, and fatty acids. Furthermore, the method was successfully validated for the quantification of 55 volatile compounds of importance in wines and applied to twelve samples of Merlot red wine from South of Brazil. The calculation of the odor activity value (OAV) showed the most important components of the samples aroma. Ethyl isovalerate, ethyl hexanoate, 1-hexanol, octanoic acid and ethyl cinnamate had the greatest contribution to the aroma of the wines analyzed, which is predominantly fruity with the presence of herbal and fatty odors. Copyright © 2017 Elsevier B.V. All rights reserved.

A Burke-Schumann Analysis of Dual-Flame Structure Supported by a Burning Droplet

Science.gov (United States)

Nayagam, V.; Dietrich, D.; Williams, F. A.

2016-01-01

Droplet combustion experiments carried out onboard the International Space Station (ISS), using pure fuels and fuel mixtures, have shown that quasi-steady burning can be sustained by a non-traditional flame configuration, namely a "cool flame" burning in the "partial-burning" regime where both fuel and oxygen leak through the low-temperature controlled flame-sheet. Recent experiments involving large, bi-component fuel (n-decane and hexanol, 50/50 by volume) droplets at elevated pressures show that the visible, hot flame becomes extremely weak while the burning rate remains relatively high, suggesting the possibility of simultaneous presence of "cool" and "hot" flames of roughly equal importance. The radiant output from these bi-component droplets is relatively high and cannot be accounted for only by the presence of a visible hot-flame. In this analysis we explore the theoretical possibility of a dual-flame structure, where one flame lies close to the droplet surface called the "cool-flame," and other farther away from the droplet surface, termed the "hot-flame." A Burke-Schumann analysis of this dual-structure seems to indicate such flame structures are possible over a narrow range of initial conditions. Theoretical results can be compared against available experimental data for pure and bi-component fuel droplet combustion to test how realistic the model may be.

Thermal properties of ionic systems near the liquid-liquid critical point.

Science.gov (United States)

Méndez-Castro, Pablo; Troncoso, Jacobo; Pérez-Sánchez, Germán; Peleteiro, José; Romaní, Luis

2011-12-07

Isobaric heat capacity per unit volume, C(p), and excess molar enthalpy, h(E), were determined in the vicinity of the critical point for a set of binary systems formed by an ionic liquid and a molecular solvent. Moreover, and, since critical composition had to be accurately determined, liquid-liquid equilibrium curves were also obtained using a calorimetric method. The systems were selected with a view on representing, near room temperature, examples from clearly solvophobic to clearly coulombic behavior, which traditionally was related with the electric permittivity of the solvent. The chosen molecular compounds are: ethanol, 1-butanol, 1-hexanol, 1,3-dichloropropane, and diethylcarbonate, whereas ionic liquids are formed by imidazolium-based cations and tetrafluoroborate or bis-(trifluromethylsulfonyl)amide anions. The results reveal that solvophobic critical behavior-systems with molecular solvents of high dielectric permittivity-is very similar to that found for molecular binary systems. However, coulombic systems-those with low permittivity molecular solvents-show strong deviations from the results usually found for these magnitudes near the liquid-liquid phase transition. They present an extremely small critical anomaly in C(p)-several orders of magnitude lower than those typically obtained for binary mixtures-and extremely low h(E)-for one system even negative, fact not observed, up to date, for any liquid-liquid transition in the nearness of an upper critical solution temperature. © 2011 American Institute of Physics

Determination of volatile compounds in grape distillates by solid-phase extraction and gas chromatography.

Science.gov (United States)

Lukić, Igor; Banović, Mara; Persurić, Dordano; Radeka, Sanja; Sladonja, Barbara

2006-01-06

Solid-phase extraction (SPE) procedure on octadecylsilica (C18) was developed for accumulation of volatile compounds from grape distillates. The procedure was optimised for final analysis by capillary gas chromatography. At mass concentrations in model solutions ranging from 0.1 to 50 mg/l solid-phase extraction recoveries of all analytes ranged from 69% for 2-phenylethanol to 102% for capric acid, with RSD values from 2 to 9%. SPE recoveries of internal standards to be added in the sample solution prior to extraction, higher alcohols 2-ethyl-1-hexanol and 1-undecanol, were 97 and 93%, respectively, with RSD values of 3%. Detection limits of analyzed compounds in model solutions ranged from 0.011 mg/l for isoamyl acetate to 0.037 mg/l for caproic acid. Method efficiency was tested in relation to acetic acid content, volume fraction of ethanol and possible matrix effects. A significant influence of matrix on SPE efficiency for geraniol, cis-2-hexen-1-ol and cis-3-hexen-1-ol was detected. For the same reason, 2-phenylethanol could not be determined by developed SPE method in samples of grape distillates. The developed solid-phase extraction method was successfully applied to determine the differences in volatile compound content in different grape distillates produced by the distillation of crushed, pressed and fermented grapes.

Effects of Basal Defoliation on Wine Aromas: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Yu Wang

2018-03-01

Full Text Available Basal defoliation, as one of the most common viticulture management practices to modify fruit zone microclimates, has been widely applied aiming at improving wine quality. Wine aroma contributes greatly to wine quality, yet the effects of basal defoliation on wine aromas show discrepancies according to previous studies. This study is a meta-analysis performed to dissect the factors related to the influence of basal defoliation on volatile compounds in wine. Timing of basal defoliation plays an important role in the concentration of varietal aromas in wine. Pre-veraison defoliation induces an increase in β-damascenone and linalool as well as a reduction in 3-isobutyl-2-methoxypyrazine (IBMP. The effects of basal defoliation on certain volatile compounds relative to fermentation aromas in wine (1-hexanol, β-phenylethanol, 2-phenylethyl acetate, decanoic acid, and ethyl octanoate depend on grape maturity. There are also other factors, such as cultivar and climate conditions, that might be responsible for the effect of basal defoliation on wine aromas. The concentrations of isobutanol, isoamyl alcohol, hexanoic acid, and octanoic acid as well as ethyl isobutyrate, ethyl hexanoate, ethyl isovalerate, and ethyl decanoate in wine are not markedly affected by basal defoliation. Due to limited studies included in this meta-analysis, more trials are needed to confirm the current findings.

Prediction of solubilities for ginger bioactive compounds in hot water by the COSMO-RS method

Science.gov (United States)

Zaimah Syed Jaapar, Syaripah; Azian Morad, Noor; Iwai, Yoshio

2013-04-01

The solubilities in water of four main ginger bioactives, 6-gingerol, 6-shogaol, 8-gingerol and 10-gingerol, were predicted using a conductor-like screening model for real solvent (COSMO-RS) calculations. This study was conducted since no experimental data are available for ginger bioactive solubilities in hot water. The σ-profiles of these selected molecules were calculated using Gaussian software and the solubilities were calculated using the COSMO-RS method. The solubilities of these ginger bioactives were calculated at 50 to 200 °C. In order to validate the accuracy of the COSMO-RS method, the solubilities of five hydrocarbon molecules were calculated using the COSMO-RS method and compared with the experimental data in the literature. The selected hydrocarbon molecules were 3-pentanone, 1-hexanol, benzene, 3-methylphenol and 2-hydroxy-5-methylbenzaldehyde. The calculated results of the hydrocarbon molecules are in good agreement with the data in the literature. These results confirm that the solubilities of ginger bioactives can be predicted using the COSMO-RS method. The solubilities of the ginger bioactives are lower than 0.0001 at temperatures lower than 130 °C. At 130 to 200 °C, the solubilities increase dramatically with the highest being 6-shogaol, which is 0.00037 mole fraction, and the lowest is 10-gingerol, which is 0.000039 mole fraction at 200 °C.

Prediction of solubilities for ginger bioactive compounds in hot water by the COSMO-RS method

International Nuclear Information System (INIS)

Jaapar, Syaripah Zaimah Syed; Iwai, Yoshio; Morad, Noor Azian

2013-01-01

The solubilities in water of four main ginger bioactives, 6-gingerol, 6-shogaol, 8-gingerol and 10-gingerol, were predicted using a conductor-like screening model for real solvent (COSMO-RS) calculations. This study was conducted since no experimental data are available for ginger bioactive solubilities in hot water. The σ-profiles of these selected molecules were calculated using Gaussian software and the solubilities were calculated using the COSMO-RS method. The solubilities of these ginger bioactives were calculated at 50 to 200 °C. In order to validate the accuracy of the COSMO-RS method, the solubilities of five hydrocarbon molecules were calculated using the COSMO-RS method and compared with the experimental data in the literature. The selected hydrocarbon molecules were 3-pentanone, 1-hexanol, benzene, 3-methylphenol and 2-hydroxy-5-methylbenzaldehyde. The calculated results of the hydrocarbon molecules are in good agreement with the data in the literature. These results confirm that the solubilities of ginger bioactives can be predicted using the COSMO-RS method. The solubilities of the ginger bioactives are lower than 0.0001 at temperatures lower than 130 °C. At 130 to 200 °C, the solubilities increase dramatically with the highest being 6-shogaol, which is 0.00037 mole fraction, and the lowest is 10-gingerol, which is 0.000039 mole fraction at 200 °C.

Interfacial thermodynamics of water and six other liquid solvents.

Science.gov (United States)

Pascal, Tod A; Goddard, William A

2014-06-05

We examine the thermodynamics of the liquid-vapor interface by direct calculation of the surface entropy, enthalpy, and free energy from extensive molecular dynamics simulations using the two-phase thermodynamics (2PT) method. Results for water, acetonitrile, cyclohexane, dimethyl sulfoxide, hexanol, N-methyl acetamide, and toluene are presented. We validate our approach by predicting the interfacial surface tensions (IFT--excess surface free energy per unit area) in excellent agreement with the mechanical calculations using Kirkwood-Buff theory. Additionally, we evaluate the temperature dependence of the IFT of water as described by the TIP4P/2005, SPC/Ew, TIP3P, and mW classical water models. We find that the TIP4P/2005 and SPC/Ew water models do a reasonable job of describing the interfacial thermodynamics; however, the TIP3P and mW are quite poor. We find that the underprediction of the experimental IFT at 298 K by these water models results from understructured surface molecules whose binding energies are too weak. Finally, we performed depth profiles of the interfacial thermodynamics which revealed long tails that extend far into what would be considered bulk from standard Gibbs theory. In fact, we find a nonmonotonic interfacial free energy profile for water, a unique feature that could have important consequences for the absorption of ions and other small molecules.

Physico-Chemical Properties and Phase Behaviour of Pyrrolidinium-Based Ionic Liquids

Directory of Open Access Journals (Sweden)

Urszula Domańska

2010-04-01

Full Text Available A review of the relevant literature on 1-alkyl-1-methylpyrrolidinium-based ionic liquids has been presented. The phase diagrams for the binary systems of {1-ethyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate [EMPYR][CF3SO3] + water, or + 1-butanol} and for the binary systems of {1-propyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate [PMPYR][CF3SO3] + water, or + an alcohol (1-butanol, 1-hexanol, 1-octanol, 1-decanol} have been determined at atmospheric pressure using a dynamic method. The influence of alcohol chain length was discussed for the [PMPYR][CF3SO3]. A systematic decrease in the solubility was observed with an increase of the alkyl chain length of an alcohol. (Solid + liquid phase equilibria with complete miscibility in the liquid phase region were observed for the systems involving water and alcohols. The solubility of the ionic liquid increases as the alkyl chain length on the pyrrolidinium cation increases. The correlation of the experimental data has been carried out using the Wilson, UNIQUAC and the NRTL equations. The phase diagrams reported here have been compared to the systems published earlier with the 1-alkyl-1-methylpyrrolidinium-based ionic liquids. The influence of the cation and anion on the phase behaviour has been discussed. The basic thermal properties of pure ILs, i.e., melting temperature and the enthalpy of fusion, the solid-solid phase transition temperature and enthalpy have been measured using a differential scanning microcalorimetry technique.

Urinary volatile organic compounds as potential biomarkers for renal cell carcinoma

Science.gov (United States)

WANG, DONGCHUN; WANG, CHANGSONG; PI, XIN; GUO, LEI; WANG, YUE; LI, MINGJUAN; FENG, YUE; LIN, ZIWEI; HOU, WEI; LI, ENYOU

2016-01-01

Currently, there is no adequate, sensitive, reproducible, specific and noninvasive biomarker that can reliably be used to detect renal cell carcinoma (RCC). Previous studies have elucidated the urinary non-volatile metabolic profile of RCC. However, whether urinary volatile organic compound (VOC) profiles are able to identify RCC remains to be elucidated. In the present study, urine was collected from 22 patients with RCC and 25 healthy subjects. Principal component analysis and orthogonal partial least square discriminant analysis were used to compare the data of patients and healthy subjects, and preoperative and postoperative patients undergoing radical nephrectomy. In total, 11 VOC biomarkers were elevated in the RCC patients compared to the healthy subjects, which were phenol; decanal; 1,6-dioxacyclododecane-7,12-dione; 1-bromo-1-(3-methyl-1-pentenylidene)-2,2,3,3-tetramethyl-cyclopropane; nonanal; 3-ethyl-3-methylheptane; isolongifolene-5-ol; 2,5-cyclohexadiene-1,4-dione, 2,6-bis(1,1-dimethylethyl); tetradecane; aniline; and 2,6,10,14-tetramethyl-pentadecane. Three biomarkers were decreased in RCC patients: styrene, 4-heptanone and dimethylsilanediol. In preoperative patients, 2-ethyl-1-hexanol and cyclohexanone were elevated, while 6-t-butyl-2,2,9,9-tetramethyl-3,5-decadien-7-yne were decreased when compared to postoperative patients. Compared with the healthy subjects, RCC has a unique VOC profile, suggesting that VOC profiles may be a useful diagnostic assay for RCC. PMID:27347408

Viscosity and surface tension of binary systems of N,N-dimethylformamide with alkan-1-ols at different temperatures

International Nuclear Information System (INIS)

Mohammad, Abubaker A.; Alkhaldi, Khaled H.A.E.; AlTuwaim, Mohammad S.; Al-Jimaz, Adel S.

2013-01-01

Highlights: ► Physical properties of binary mixtures of DMF+1-pentanol, 1-hexanol, or 1-heptanol. ► Viscosity and surface tension were measured. ►Δη, Δσ σ and G ∗E were calculated using the experimental data. ► H σ and S σ were determined using the surface tension data. ► Semi-empirical relations were used to estimate the viscosity of liquid mixtures. - Abstract: Viscosity η and surface tension σ were measured for binary mixtures of N,N-dimethylformamide DMF with pentan-1-ol, hexan-1-ol, and heptan-1-ol at T = (298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure over the entire mole fraction range. Deviations in viscosity Δη and surface tension Δσ were calculated using experimental results. Moreover, the values of the excess Gibbs free energy of activation G ∗E , surface enthalpy H σ and surface entropy S σ of these mixtures were determined. Viscosity measurements of the binary systems were correlated with Grunberg and Nissan, the three-body and four-body McAllister expressions. Viscosity deviation, surface tension deviation and excess Gibbs energy of activation functions were fitted to the method of Redlich–Kister (R–K) polynomial to estimate the coefficients and standard deviations. The effects of chain length of alkan-1-ols and temperature on the thermodynamic properties of binary systems were studied.

Control of Evaporation Behavior of an Inkjet-Printed Dielectric Layer Using a Mixed-Solvent System

Science.gov (United States)

Yang, Hak Soon; Kang, Byung Ju; Oh, Je Hoon

2016-01-01

In this study, the evaporation behavior and the resulting morphology of inkjet-printed dielectric layers were controlled using a mixed-solvent system to fabricate uniform poly-4-vinylphenol (PVP) dielectric layers without any pinholes. The mixed-solvent system consisted of two different organic solvents: 1-hexanol and ethanol. The effects of inkjet-printing variables such as overlap condition, substrate temperature, and different printing sequences (continuous and interlacing printing methods) on the inkjet-printed dielectric layer were also investigated. Increasing volume fraction of ethanol (VFE) is likely to reduce the evaporation rate gradient and the drying time of the inkjet-printed dielectric layer; this diminishes the coffee stain effect and thereby improves the uniformity of the inkjet-printed dielectric layer. However, the coffee stain effect becomes more severe with an increase in the substrate temperature due to the enhanced outward convective flow. The overlap condition has little effect on the evaporation behavior of the printed dielectric layer. In addition, the interlacing printing method results in either a stronger coffee stain effect or wavy structures of the dielectric layers depending on the VFE of the PVP solution. All-inkjet-printed capacitors without electrical short circuiting can be successfully fabricated using the optimized PVP solution (VFE = 0.6); this indicates that the mixed-solvent system is expected to play an important role in the fabrication of high-quality inkjet-printed dielectric layers in various printed electronics applications.

Clonal differences and impact of defoliation on Sauvignon blanc (Vitis vinifera L.) wines: a chemical and sensory investigation.

Science.gov (United States)

Šuklje, Katja; Antalick, Guillaume; Buica, Astrid; Langlois, Jennifer; Coetzee, Zelmari A; Gouot, Julia; Schmidtke, Leigh M; Deloire, Alain

2016-02-01

The aim of this study, performed on Sauvignon blanc clones SB11 and SB316, grafted on the same rootstock 101-14 Mgt (Vitis riparia × V. ruperstris) and grown at two adjacent vineyards, was two-fold: (1) to study wine chemical and sensory composition of both clones within an unaltered canopy; and (2) to determine the effect of defoliation (e.g. bunch microclimate) on wine chemical and sensory composition. Orthogonal projection to latent structures discriminate analysis (OPLS-DA) was applied to the concentration profiles of volatile compounds derived from gas chromatography-mass spectrometry data. The loadings directions inferred that 3-isobutyl-2-methoxypyrazine (IBMP) discriminated control treatments (shaded fruit zone) of both clones from defoliation treatments (exposed fruit zone), whereas 3-sulfanyl-hexan-1-ol (3SH), 3-sulfanylhexyl acetate (3SHA), hexanol, hexyl hexanoate and some other esters discriminated defoliated treatments from the controls. The OPLS-DA indicated the importance of IBMP, higher alcohol acetates and phenylethyl esters, for discrimination of clone SB11 from clone SB316 irrespective of the treatment. Defoliation in the fruit zone significantly decreased perceived greenness in clone SB11 and elevated fruitier aromas, whereas in clone SB316 the effect of defoliation on wine sensory perception was less noticeable regardless the decrease in IBMP concentrations. These findings highlight the importance of clone selection and bunch microclimate to diversify produced wine styles. © 2015 Society of Chemical Industry.

Studies on the synthesis of silicoaluminophosphates and silicophosphates

International Nuclear Information System (INIS)

Han, Xue Song

2002-01-01

In this work, the study was carried out in the following two categories: a) Direct synthesis: SAPO 4 -5 and SiPO 4 -5 synthesis using various anionic templates was carried out, the synthesis was tested under different conditions; various gel compositions and different gel preparation methods were optimised. b) Modification: As-synthesised SAPO 4 -5 or AIPO 4 -5 was dealuminated by SiCl 4 or (NH 4 ) 2 SiF 6 . And P incorporation into SSZ-24 framework was also studied. SAPO 4 -5 with different silicon content in the framework was synthesised using sulphonate and sulphate species as surfactant in a hexanol/aqueous duo phase media. By using sulphonate and sulphate species as surfactants, the silicon content in the empirical formula of SAPO 4 -5 was increased to 0.511 while silicon content in the reaction gel being broadened to SiO 2 =3.0. By controlling the silicon content in the reaction gel, the silicon content in SAPO 4 -5 was controlled. SAPO 4 -15 was synthesised using tetraethyl/butyl ammonium toluene-4-sulphonate as template. SiPO 4 -15 was also synthesised by using tetraethyl ammonium toluene-4-sulphonate as template. The framework had positive charge regions contributed by Si-O-P bonding. The as-synthesised samples were analysed and characterised by using X-ray diffraction, X-ray fluorescence, Thermogravimetric analysis and Differential thermal analysis, Scanning electron microscopy etc. techniques. (author)

脱脂棉固定化脂肪酶的非水活性与稳定性%Nonaqueous Activity and Stability of Pseudomonas cepacia Lipase Immobilized on Absorbent Cotton Fiber

Institute of Scientific and Technical Information of China (English)

康洁; 王笑; 张莹; 周美娟; 丛方地; 邢克智

2017-01-01

Catalysis of lipases exists in nonaqueous media,but their catalysis with low activity and stability needs further improvement.That is one of bottleneck problems in nonaqueous enzymology.The desired strategy was that simulation on the interfacial activation of lipases,namely replacing water with macromolecule,to optimize,stabilize and disperse enzyme proteins so as to hold back denature in organic phases.Then the macromolecules should have numerous hydroxyl groups,large specific surface,inert and compatibility with enzyme proteins.Absorbent cotton fiber happened to own these characteristics and was employed as immobilization carrier to prepare immobilized Pseudomonas cepacia lipase in a mass ratio of 1 ∶ 0.9 (lipase:cotlon) by physical adsorption.In catalyzing transesterification between hexanol and vinyl acetate,the prepared cotton-lipase was 3.7 folds of native lipase in transformation ability of hexanol after 1 hour.In a catalytic cycle of 6 times and 6 hours once,the ability of immobilized and native lipases transforming substrate averagely was reduced by about 0.3％ and 2.4％,respectively.It showed that cotton-lipase had obvious increase in the nonaqueous activity,especially the stability.This study presented a way for effective enhancement of nonaqueous catalysis of lipases by immobilization method so as to meet the requirements on their applications in industry.%脂肪酶具有非水催化作用,但其非水催化活性和稳定性需进一步提高,这是非水酶学的瓶颈问题之一.理想的策略是模拟脂肪酶的界面活化机制,以大分子代替水,优化、稳定化和有效分散酶蛋白,阻止其在有机相中变性.因此,选用多羟基、比表面积大、惰性、且与酶蛋白能兼容的大分子——脱脂棉纤维,作为固定化载体,以1∶0.9的质量比,通过物理吸附,将假单胞菌脂肪酶(Pseudomonas cepacia lipase)固定在脱脂棉纤维上.在催化己醇与乙酸乙烯酯的转酯反应中,反应1h

A selected ion flow tube study of the reactions of H3O+, NO+ and O-2(+center dot) with seven isomers of hexanol in support of SIFT-MS

Czech Academy of Sciences Publication Activity Database

Smith, D.; Sovová, Kristýna; Španěl, Patrik

2012-01-01

Roč. 319, MAY 1 2012 (2012), s. 25-30 ISSN 1387-3806 R&D Projects: GA ČR GA203/09/0256 Institutional support: RVO:61388955 Keywords : selected ion flow tube mass spectrometry * proton transfer * ion molecule reaction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.142, year: 2012

A narrow pH range supports butanol, hexanol, and octanol production from syngas in a continuous co-culture of Clostridium ljungdahlii and Clostridium kluyveri with in-line product extraction

NARCIS (Netherlands)

Richter, Hanno; Molitor, Bastian; Diender, Martijn; Machado de Sousa, Diana; Angenent, Largus T.

2016-01-01

Carboxydotrophic bacteria (CTB) have received attention due to their ability to synthesize commodity chemicals from producer gas and synthesis gas (syngas). CTB have an important advantage of a high product selectivity compared to chemical catalysts. However, the product spectrum of wild-type CTB

Chemical flowsheet conditions for preparing urania spheres by internal gelation

International Nuclear Information System (INIS)

Haas, P.A.; Begovich, J.M.; Ryon, A.D.; Vavruska, J.S.

1979-01-01

Small, ceramic urania spheres can be prepared for use as nuclear fuel by internal chemical gelation of uranyl nitrate solution droplets. Decomposition of hexamethylenetetramine (HMTA) dissolved in the uranyl nitrate solution releases ammonia to precipitate hydrated UO 3 . Previously established flowsheet conditions have been improved and modified at ORNL and have been applied to prepare dense UO 2 spheres with average diameters of 1200, 300, and 30 μm. Acid-deficient uranyl nitrate (ADUN) solutions up to 3.4 M in uranium with NO 3 - /U mole ratios of 1.5 to 1.7 are prepared by dissolution of U 3 O 8 or UO 3 . Continuous mixing of metered, cooled ADUN containing urea and HMTA solutions provides a smooth, regulated flow of the temperature-sensitive feed solution. The gelation times for solution drops in organic liquids at 45 to 95 0 C depend on both the chemical reaction rates and the rates of heat transfer. The gel properties vary with temperature and other gelation variables. Gelation conditions were determined which allow easy washing, drying, firing, and sintering to produce dense UO 2 spheres of all three sizes. The 1200- and 300-μm UO 2 spheres were pepared by gelation in trichloroethylene at 50 to 65 0 C; 2-ethyl-l-hexanol was used as the gelation medium to prepare 30-μm UO 2 spheres. Washing and drying requirements were determined. The gel dried to 225 0 C contains about 95% UO 3 ; the remaining components are H 2 O, NH 3 - , which are volatilized during firing to UO 2

Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Annual report 2012/2013; Fraunhofer Institut fuer Molekularbiologie und Angewandte Oekologie (IME). Jahresbericht 2012/2013

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-03-15

The Annual report 2012/2013 of the Fraunhofer Institute for molecular biology and applied ecology includes the following contributions: (A) Molecular Biology: A technology platform for human monoclonal antibodies against malaria antigens. Reducing the cold sweetening of potatoes during cold storage. BY2 cell - free lysate: an alternative eucaryotic in vitro translation system. Automated animal cell culture. Improvement of resource-use efficiency and productivity in crop plants. Optimizing transient protein expression in tobacco using predictive models. Microbial master-cell banks for biopharmaceutical production. Development and implementation of a plant-produced vaccine against yellow fever. Insect antennae as in situ biosensors. Communal and individual immunity - their relationship in Tribolium castaneum. A Drosophila model for aging. Analysis of insect transcriptomes, Biofuels: Hexanol production with Clostridia. Application of Targeted Proteomics for Metabolic Engineering of Clostridia. The Fraunhofer Future Foundation Malaria Project. Characterization and validation of predictive human experimental pain models. FCR Center for Systems Biotechnology business areas progress report. (B) Applied Ecology: Transformation/dissolution testing of silver nanoparticles. Effect of silver nanoparticles in the context of sewage sludge used in agriculture. Feasibility of biotic ligand models for routine monitoring. Estimating reasonable application dates related to BBCH crop development stages. Bioconcentration studies with the freshwater amphipod Hyalella azteca. Fish life cycle tests: Static vs. flow-through exposure. Vulnerable fish species for risk assessment of pesticides in Europe. Ecotoxicological testing of armor stones in mesocosms. The effect of wild yeast in traditional wines. Lifestock metabolism studies at Fraunhofer IME. Column generated concentrations of highly-lipophilic test substances.

Synthesis and characterization of oleic acid surface modified magnetic iron oxide nanoparticles by using biocompatible w/o microemulsion for heavy metal removal

Science.gov (United States)

Rose, Laili Che; Suhaimi, Hamdan; Mamat, Mazidah; Lik, Thang Zhe

2017-09-01

Oleic acid modified magnetic iron oxide nanoparticles (OA-MIONs) was prepared for removal of Cu2+ ion from aqueous solution. OA-MIONs was prepared by W/O microemulsion template which composed of mixed non-ionic surfactants and 1-hexanol as emulsifier. The effect of weight ratio of the constituent of microemulsion template on the physical and chemical properties of OA-MIONs was studied by characterization using Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) analysis. FT-IR spectra showed that all templates shared similar chemical structure with slight difference in the peak intensity. Scanning electron micrograph illustrated that the OA-MIONs synthesized via template with the lowest weight ratio of emulsifier to heptane had a more regular spherical shape and was well-distributed. XRD had confirmed that the identity of synthesized OA-MIONs was Fe3O4. Based on the characterization result, the template with lowest weight ratio of emulsifier to heptane was chosen for the heavy metal adsorption study. The adsorption capacity OA-MIONs as a function of pH, contact time and adsorbent dosage were studied. The adsorption process reached equilibrium for 90 minutes and successfully adsorbed 43% of Cu2+ ion from aqueous solution. The adsorption behavior was well described by Langmuir isotherm. The maximum adsorption capacity was determined and found to be 555.56 mg/g. The value of Langmuir equilibrium parameter, RL was found between 0 and 1, suggested that a favorable monolayer adsorption process had taken out.

Enhanced percutaneous permeability of diclofenac using a new U-type dilutable microemulsion.

Science.gov (United States)

Shevachman, Marina; Garti, Nissim; Shani, Arnon; Sintov, Amnon C

2008-04-01

Enhanced systemic absorption in vivo and percutaneous penetration in vitro was demonstrated after transdermal administration of diclofenac sodium formulated in U-type microemulsion. Diclofenac sodium was solubilized in a typical four-component system consisting of an oil, polyoxyethylene-10EO-oleyl alcohol (Brij 96V) as the surfactant, and 1-hexanol along water dilution line W46 (40 wt % surfactant and 60 wt % oil phase before water titration). Viscosity and small angle X-ray scattering measurements have evidenced bicontinuous structures within water fractions of 0.25 and 0.5 along the dilution line. Self-diffusion NMR studies showed that drug molecules accumulated in the interfacial film and, to some extent, dissolved in the oil. Relative to a commercial macro-emulsion cream (Voltaren Emulgel), microemulsions containing paraffin oil or isopropyl myristate increased the in vivo transdermal penetration rate of diclofenac by two order of magnitude, whereas the rat plasma levels were increased by one order of magnitude. The in vitro data obtained from excised rat skin were comparable to the in vivo results, but suffered from discrepancies from the ideal in vivo-in vitro correlation, which might be explained by optimal in vitro conditions of perfusion and hydration. It has also been found that when jojoba oil is formulated as the oil phase in the microemulsion, the penetration rate of the drug decreases significantly. Based on the three-dimensional structure of jojoba oil, the wax is presumed to prevent the drug from being freely diffused into the skin while migrating from the interfacial film into the continuous oil phase.

The behaviour of organic solvents containing C5-BTBP and CyMe4-BTBP at low irradiation doses

International Nuclear Information System (INIS)

Retegan, T.; Fermvik, A.; Skarnemark, G.; Foreman, M.R.S.

2007-01-01

Low doses of gamma radiation were given to four different solvents containing C5-BTBP and CyMe 4 -BTBP, each molecule dissolved both in cyclohexanone and hexanol. Four corresponding solvents were kept unirradiated and used as references for the extraction experiments. Multiple samples were taken from both the irradiated solutions and the reference solutions at certain time intervals. The samples were used in extraction experiments with the radionuclides 241 Am and 152 Eu. The protection against radiolysis of the extracting molecules by the diluent used for dissolution without adding a scavenger molecule was checked. The interplay between the diluent and the side group of the extracting molecule for protection against radiolysis was also studied by keeping the same type of core molecule for binding to the metal ions and varying the diluent and side group. The results were unexpected. The presence of a cyclic molecule as both a side group or diluent seems to keep the extraction of europium almost unaffected by radiolysis, while americium behaves differently from solvent to solvent. The diluent alone does not protect the extracting molecule. In some of the studied systems there is a distinct change in the extraction behaviour of Am between the irradiated and reference solutions, an effect that is however only present at the beginning of the experimental series. At later times the difference in distribution ratios between the irradiated and reference solution is constant. This phenomenon is found only when the side group and diluent are structurally dissimilar. (orig.)

Two-chiral-component microemulsion electrokinetic chromatography-chiral surfactant and chiral oil: part 1. dibutyl tartrate.

Science.gov (United States)

Kahle, Kimberly A; Foley, Joe P

2007-06-01

The first simultaneous use of a chiral surfactant and a chiral oil for microemulsion EKC (MEEKC) is reported. Six stereochemical combinations of dodecoxycarbonylvaline (DDCV: R, S, or racemic, 2.00% w/v), racemic 2-hexanol (1.65% v/v), and dibutyl tartrate (D, L, or racemic, 1.23% v/v) were examined as chiral pseudostationary phases (PSPs) for the separation of six pairs of pharmaceutical enantiomers: pseudoephedrine, ephedrine, N-methyl ephedrine, metoprolol, synephrine, and atenolol. Subtle differences were observed for three chromatographic figures of merit (alpha(enant), alpha(meth), k) among the chiral microemulsions; a moderate difference was observed for efficiency (N) and elution range. Dual-chirality microemulsions provided both the largest and smallest enantioselectivities, due to small positive and negative synergies between the chiral microemulsion components. For the ephedrine family of compounds, dual-chiral microemulsions with surfactant and oil in opposite stereochemical configurations provided higher enantioselectivities than the single-chiral component microemulsion (RXX), whereas dual-chiral microemulsions with surfactant and oil in the same stereochemical configurations provided lower enantioselectivities than RXX. Slight to moderate enantioselective synergies were confirmed using a thermodynamic model. Efficiencies observed with microemulsions comprised of racemic dibutyl tartrate or dibutyl-D-tartrate were significantly higher than those obtained with dibutyl-L-tartrate, with an average difference in plate count of about 25 000. Finally, one two-chiral-component microemulsion (RXS) provided significantly better resolution than the remaining one- and two-chiral-component microemulsions for the ephedrine-based compounds, but only slightly better or equivalent resolution for non-ephedrine compounds.

Antimicrobial Potential and Chemical Characterization of Serbian Liverwort (Porella arboris-vitae: SEM and TEM Observations

Directory of Open Access Journals (Sweden)

Amit Kumar Tyagi

2013-01-01

Full Text Available The chemical composition of Porella arboris-vitae extracts was determined by solid phase microextraction, gas chromatography-mass spectrometry (SPME GC-MS, and 66 constituents were identified. The dominant compounds in methanol extract of P. arboris-vitae were β-caryophyllene (14.7%, α-gurjunene (10.9%, α-selinene (10.8%, β-elemene (5.6%, γ-muurolene (4.6%, and allo-aromadendrene (4.3% and in ethanol extract, β-caryophyllene (11.8%, α-selinene (9.6%, α-gurjunene (9.4%, isopentyl alcohol (8.8%, 2-hexanol (3.7%, β-elemene (3.7%, allo-aromadendrene (3.7%, and γ-muurolene (3.3% were the major components. In ethyl acetate extract of P. arboris-vitae, undecane (11.3%, β-caryophyllene (8.4%, dodecane (6.4%, α-gurjunene (6%, 2-methyldecane (5.1%, hemimellitene (4.9%, and D-limonene (3.9% were major components. The antimicrobial activity of different P. arboris-vitae extracts was evaluated against selected food spoilage microorganisms using microbroth dilution method. The Minimal Inhibitory Concentration (MIC varied from 0.5 to 1.5 mg/mL and 1.25 to 2 mg/mL for yeast and bacterial strains, respectively. Significant morphological and ultrastructural alterations due to the effect of methanolic and ethanolic P. arboris-vitae extracts on S. Enteritidis have also been observed by scanning electron microscope and transmission electron microscope, respectively. The results provide the evidence of antimicrobial potential of P. arboris-vitae extracts and suggest its potential as natural antimicrobial agents for food preservation.

Behavioral responses of the diamondback moth, Plutella xylostella, to green leaf volatiles of Brassica oleracea subsp. capitata.

Science.gov (United States)

Reddy, G V; Guerrero, A

2000-12-01

Green leaf volatiles (GLVs) from Brassica oleracea subsp. capitata L. have been identified as 1-hexanol, (Z)-3-hexen-1-ol, 1-hexen-3-ol, hexanal, (E)-2-hexenal, hexyl acetate, and (Z)-3-hexenyl acetate, by their mass spectra and retention times in comparison with authentic samples. No isothiocyanates were found in the extract. The activity of these chemicals has been determined on mated and unmated males and females of the diamondback moth (DBM) Plutella xylostella in the laboratory (wind tunnel) and in the field. On unmated males, mixtures of (Z)-3-hexenyl acetate, (E)-2-hexenal, and (Z)-3-hexen-1-ol with the pheromone induced attractant/arresting behavior in 80-100% of the males tested, significantly higher than the effect induced by the pheromone alone. On mated males and unmated females the effect of the GLVs alone or in combination with the pheromone was poor, while on mated females these compounds elicited upwind flight and arresting behavior in 40-60% of the females assayed. There was no synergism when these chemicals were mixed with the pheromone. In the field, (Z)-3-hexenyl acetate, the most active GLV in laboratory tests, when mixed with the pheromone in 1:1 ratio, enhanced 6-7-fold the number of females and 20-30% the number of males caught by traps over those baited with the pheromone alone. Our results indicate that the enhancement of the attraction of both males and females of the DBM to traps baited with pheromone blended with the relatively inexpensive and environmentally safe (Z)-3-hexenyl acetate may be important for future control strategies of the pest.

Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system

Energy Technology Data Exchange (ETDEWEB)

Serna-Galvis, Efraím A.; Silva-Agredo, Javier [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Giraldo-Aguirre, Ana L. [Grupo de Diseño y Formulación de Medicamentos, Cosméticos y Afines (DYFOMECO), Facultad de Química Farmacéutica, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Torres-Palma, Ricardo A., E-mail: ricardo.torres@udea.edu.co [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

2015-08-15

Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20–60 W), dissolved gas (air, Ar and He), pH (3–11) and initial concentration of fluoxetine (2.9–162.0 μmol L{sup −1}). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe{sup 2+}) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. - Highlights: • The pharmaceutical fluoxetine was effectively eliminated upon ultrasonic action. • Ultrasonic power, dissolved gas, pH and concentration of fluoxetine were evaluated. • Fe{sup 2+}, sodium nitrate or nitric acid had a positive effect on the FLX degradation. • More hydrophobic or volatile compounds than fluoxetine diminished the efficiency. • A sonochemical-biological combined process led to the total mineralization of FLX.

"Fooling fido"--chemical and behavioral studies of pseudo-explosive canine training aids.

Science.gov (United States)

Kranz, William D; Strange, Nicholas A; Goodpaster, John V

2014-12-01

Genuine explosive materials are traditionally employed in the training and testing of explosive-detecting canines so that they will respond reliably to these substances. However, challenges arising from the acquisition, storage, handling, and transportation of explosives have given rise to the development of "pseudo-explosive" training aids. These products attempt to emulate the odor of real explosives while remaining inert. Therefore, a canine trained on a pseudo-explosive should respond to its real-life analog. Similarly, a canine trained on an actual explosive should respond to the pseudo-explosive as if it was real. This research tested those assumptions with a focus on three explosives: single-base smokeless powder, 2,4,6-trinitrotoluene (TNT), and a RDX-based plastic explosive (Composition C-4). Using gas chromatography-mass spectrometry with solid phase microextraction as a pre-concentration technique, we determined that the volatile compounds given off by pseudo-explosive products consisted of various solvents, known additives from explosive formulations, and common impurities present in authentic explosives. For example, simulated smokeless powders emitted terpenes, 2,4-dinitrotoluene, diphenylamine, and ethyl centralite. Simulated TNT products emitted 2,4- and 2,6-dinitrotoluene. Simulated C-4 products emitted cyclohexanone, 2-ethyl-1-hexanol, and dimethyldinitrobutane. We also conducted tests to determine whether canines trained on pseudo-explosives are capable of alerting to genuine explosives and vice versa. The results show that canines trained on pseudo-explosives performed poorly at detecting all but the pseudo-explosives they are trained on. Similarly, canines trained on actual explosives performed poorly at detecting all but the actual explosives on which they were trained.

Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

Energy Technology Data Exchange (ETDEWEB)

Jambon, C

1962-07-01

After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

Novel graphene papers with sporadic alkyl brushes on the basal plane as a high-capacity flexible anode for lithium ion batteries

International Nuclear Information System (INIS)

Oh, Kyung Min; Cho, Sung-Woo; Kim, Gyeong-Ok; Ryu, Kwang-Sun; Jeong, Han Mo

2014-01-01

Graphene paper that exhibits an excellent stabilized capacity, as high as 1300 mAh g −1 at a current rate of 60 mA g −1 , as a lithium ion battery anode is fabricated and evaluated. The few-layer graphene used to make the graphene paper is prepared via the thermal reduction of graphite oxide. The graphene is then modified by a novel method utilizing inherent defects, namely epoxy groups, on the graphene as active sites for a reaction with methanol, 1-butanol, 1-hexanol, and 1-octanol. The density values and X-ray diffraction patterns obtained for the graphene paper demonstrate that the alkyl brushes on the graphene sheets expand the d-spacing and hinder close restacking of the sheets, thereby inducing the formation of extra cavities within the paper. This loose packing due to the alkyl brushes increases sensitively as the alkyl chain length of the alcohol becomes longer. The lithium ion insertion capacity of a graphene paper electrode at the first cycle also increases with the alkyl chain length. However, fading of the capacity at early charge/discharge cycles is accelerated by the modification process because of electrolyte penetration into the gallery and the acceleration of protective solid electrolyte interface film formation due to looser packing. The paper composed of graphene modified with 1-butanol rather than shorter or longer alcohols exhibits the best reversible storage capacity, more than two-fold higher when compared to that of pristine graphene paper, due to a compromise between two conflicting effects on the reversible storage capacity by long alkyl brushes. The tensile properties and electrical conductivity of the graphene papers are also examined

Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets

Science.gov (United States)

Kremer, J.; Kilzer, A.; Petermann, M.

2018-01-01

Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

Energy Technology Data Exchange (ETDEWEB)

Jambon, C

1962-07-01

After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

Two-chiral component microemulsion EKC - chiral surfactant and chiral oil. Part 2: diethyl tartrate.

Science.gov (United States)

Kahle, Kimberly A; Foley, Joe P

2007-08-01

In this second study on dual-chirality microemulsions containing a chiral surfactant and a chiral oil, a less hydrophobic and lower interfacial tension chiral oil, diethyl tartrate, is employed (Part 1, Foley, J. P. et al.., Electrophoresis, DOI: 10.1002/elps.200600551). Six stereochemical combinations of dodecoxycarbonylvaline (DDCV: R, S, or racemic, 2.00% w/v), racemic 2-hexanol (1.65% v/v), and diethyl tartrate (D, L, or racemic, 0.88% v/v) were examined as pseudostationary phases (PSPs) for the enantioseparation of six chiral pharmaceutical compounds: pseudoephedrine, ephedrine, N-methyl ephedrine, metoprolol, synephrine, and atenolol. Average efficiencies increased with the addition of a chiral oil to R-DDCV PSP formulations. Modest improvements in resolution and enantioselectivity (alpha(enant)) were achieved with two-chiral-component systems over the one-chiral-component microemulsion. Slight enantioselective synergies were confirmed using a thermodynamic model. Results obtained in this study are compared to those obtained in Part 1 as well as those obtained with chiral MEEKC using an achiral, low-interfacial-tension oil (ethyl acetate). Dual-chirality microemulsions with the more hydrophobic oil dibutyl tartrate yielded, relative to diethyl tartrate, higher efficiencies (100,000-134,000 vs. 80,800-94,300), but lower resolution (1.64-1.91 vs. 2.08-2.21) due to lower enantioselectivities (1.060-1.067 vs. 1.078-1.081). Atenolol enantiomers could not be separated with the dibutyl tartrate-based microemulsions but were partially resolved using diethyl tartrate microemulsions. A comparable single-chirality microemulsion based on the achiral oil ethyl acetate yielded, relative to diethyl tartrate, lower efficiency (78 300 vs. 91 600), higher resolution (1.99 vs. 1.83), and similar enantioselectivities.

Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system

International Nuclear Information System (INIS)

Serna-Galvis, Efraím A.; Silva-Agredo, Javier; Giraldo-Aguirre, Ana L.; Torres-Palma, Ricardo A.

2015-01-01

Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20–60 W), dissolved gas (air, Ar and He), pH (3–11) and initial concentration of fluoxetine (2.9–162.0 μmol L −1 ). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe 2+ ) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. - Highlights: • The pharmaceutical fluoxetine was effectively eliminated upon ultrasonic action. • Ultrasonic power, dissolved gas, pH and concentration of fluoxetine were evaluated. • Fe 2+ , sodium nitrate or nitric acid had a positive effect on the FLX degradation. • More hydrophobic or volatile compounds than fluoxetine diminished the efficiency. • A sonochemical-biological combined process led to the total mineralization of FLX

In-syringe-stirring: A novel approach for magnetic stirring-assisted dispersive liquid–liquid microextraction

International Nuclear Information System (INIS)

Horstkotte, Burkhard; Suárez, Ruth; Solich, Petr; Cerdà, Víctor

2013-01-01

Graphical abstract: -- Highlights: •We propose a new automatic magnetic stirring assisted dispersive liquid–liquid microextraction. •It allows the extraction of aluminum from seawater and freshwater samples within less than 4 min. •The method was applicable to the natural samples. -- Abstract: For the first time, the use of a magnetic stirrer within the syringe of an automated syringe pump and the resulting possible analytical applications are described. A simple instrumentation following roughly the one from sequential injection analyzer systems is used in combination with an adaptor, which is placed onto the barrel of a glass syringe. Swirling around the longitudinal axis of the syringe and holding two strong neodymium magnets, it causes a rotating magnetic field and serves as driver for a magnetic stirring bar placed inside of the syringe. In a first study it was shown that this approach leads to a sealed but also automatically adaptable reaction vessel, the syringe, in which rapid and homogeneous mixing of sample with the required reagents within short time can be carried out. In a second study in-a-syringe magnetic stirring-assisted dispersive liquid–liquid microextraction (MSA-DLLME) was demonstrated by the application of the analyzer system to fluorimetric determination of aluminum in seawater samples using lumogallion. A linear working range up to 1.1 μmol L −1 and a limit of detection of 6.1 nmol L −1 were found. An average recovery of 106.0% was achieved for coastal seawaters with a reproducibility of 4.4%. The procedure lasted 210 s including syringe cleaning and only 150 μL of hexanol and 4.1 mL of sample were required

Volatile composition and sensory profile of Cantharellus cibarius Fr. as affected by drying method.

Science.gov (United States)

Politowicz, Joanna; Lech, Krzysztof; Sánchez-Rodríguez, Lucía; Szumny, Antoni; Carbonell-Barrachina, Ángel A

2017-12-01

In this work, the influence of different drying methods on the aroma composition and sensory quality of chanterelle mushrooms (Cantharellus cibarius Fr.) was evaluated. The drying methods tested were convective drying (CD), freeze drying (FD), vacuum microwave drying (VMD) and a combination of convective pre-drying and vacuum microwave finish drying (CPD-VMFD). Analyses of fresh and dried chanterelle samples by HS-SPME and GC/MS and GC-FID showed the presence of 39 volatile compounds at different concentrations. The most abundant compounds in fresh chanterelle were 1-hexanol (33.4 μg per 100 g dry basis (db)), 1-octen-3-ol (80.2 μg per 100 g db) and 2-octen-1-ol (19.3 μg per 100 g db). The results showed that fresh and dried chanterelle contained very low levels of aroma compounds; however, the highest contents of volatile compounds were found in samples after (i) CD at 80 °C (129 μg per 100 g db), (ii) CPD-VMFD at 70 °C-480/240 W (136 μg per 100 g db) and (iii) CPD-VMFD at 80 °C-480/240 W (136 μg per 100 g db). The best dehydration methods, which resulted in high contents of volatile compounds and appropriate sensory quality, according to descriptive sensory analysis and PCA tools, were CD at 70 and 80 °C. Besides, these methods led to spongy dried mushrooms with high intensities of fresh, mushroom ID, with proper color and without intense shrinkage. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Odor experiences during preimaginal stages cause behavioral and neural plasticity in adult honeybees

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Gabriela eRamirez

2016-06-01

Full Text Available In eusocial insects, experiences acquired during the development have long-term consequences on mature behavior. In the honeybee that suffers profound changes associated with metamorphosis, the effect of odor experiences at larval instars on the subsequent physiological and behavioral response is still unclear. To address the impact of preimaginal experiences on the adult honeybee, colonies containing larvae were fed scented food. The effect of the preimaginal experiences with the food odor was assessed in learning performance, memory retention and generalization in 3-5- and 17-19-day-old bees, in the regulation of their expression of synaptic-related genes and in theperception and morphology of their antennae. Three-5 day old bees that experienced 1-hexanol (1-HEX as food scent responded more to the presentation of the odor during the 1-HEX conditioning than control bees (i.e. bees reared in colonies fed unscented food. Higher levels of PER to 1-HEX in this group also extent to HEXA, the most perceptually similar odor to the experienced one that we tested. These results were not observed for the group tested at older ages. In the brain of young adults, larval experiences triggered similar levels of neurexins and neuroligins expression, two proteins that have been involved in synaptic formation after associative learning. At the sensory periphery, the experience did not alter the number of the olfactory sensilla placoidea, but did reduce the electrical response of the antennae to the experienced and novel odor. Our study provides a new insight into the effects of preimaginal experiences in the honeybee and the mechanisms underlying olfactory plasticity at larval stage of holometabolous insects.

The influence of the different techniques of maceration on the aromatic and phenolic profile of the Busuioacă de Bohotin wine

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Tartian Alexandru C.

2017-01-01

Full Text Available The main objective of the present study is to evaluate the influence of the maceration techniques on the volatile and phenolic compounds content of the wines obtained from an autochthonous aromatic variety from Romania. For this study, a pink biotype of the Busuioacă de Bohotin variety from the Huşi vineyard was used. The wine samples were obtained by applying five types of maceration: Classic maceration (V1; S1, Thermo-maceration (V2; S2, Microwave maceration (V3; S3, Ultrasound maceration (V4; S4 and Cryo-maceration (V5; S5. The results of the aromatic profile of the wine samples obtained from Busuioacă de Bohotin variety, indicated that the wine samples obtained through cryo-maceration and classic maceration contained a large variety of volatile compounds, namely: alcohols (1-propanol; 2-methyl-1-propanol, 3-methyl-1-butanol, 1-hexanol, phenethyl alcohol e.g., esters (ethyl octanoate; ethyl caprylate; ethyl lactate; ethyl benzoate; ethyl palmitate e.g. terpenoid compounds (α-terpineol, linalool, hotrienol, citronellol, nerol, geraniol and so an. Among alcohols, phenethyl alcohol, which is responsible for floral aroma of roses and is typical for the Busuioacă de Bohotin wine, was found in large quantities in wine samples V1 (4.3 mmol/L and S5 (5.53 mmol/L. Terpene compounds and their oxides were identified with elevated levels for linalool (cis- and trans- and also nerol- as well as linalool-oxide. Analysing the phenolic compounds, it was observed that the total polyphenol index and Folin-Ciocâlteu index expressed higher values for the wine samples V1 and V3. Concerning the total anthocyanins and tannins content, the wine samples obtained had low amounts of this compounds.

Chemical composition and vascular and intestinal smooth muscle relaxant effects of the essential oil from Psidium guajava fruit.

Science.gov (United States)

Rasheed, Hafiz Majid; Khan, Taous; Wahid, Fazli; Khan, Rasool; Shah, Abdul Jabbar

2016-11-01

Psidium guajava L. (Myrtaceae) is widely used in traditional medicine for the treatment of various ailments including cardiovascular and gastrointestinal disorders. The current study investigated the chemical composition and cardiovascular and gastrointestinal effects of the essential oil of P. guajava. The chemical composition of the essential oil was investigated using gas chromatography-mass spectrometry (GC-MS) technique. The biological activity of the essential oil was tested on rabbit aorta and jejunum. All changes in isometric tension were recorded through a force transducer coupled with a bridge amplifier data acquisition system. GC-MS analysis showed the presence of butanoic acid methyl ester, 3-methyl glutaric anhydride, 1-butanol, 3-hexenal, cinnamyl alcohol, 1-hexanol and hexane as the major components. In isolated rabbit aorta preparations, the essential oil showed vasorelaxation at doses of 3-10 mg/mL against high K +  and phenylephrine pre-contractions with EC 50 values of 5.52 (5-6.04) and 6.23 mg/mL (5.0-7.46). The essential oil inhibited spontaneous and high K +  induced contractions in isolated rabbit jejunum with EC 50 values of 0.84 (0.3-1.38) and 0.71 mg/mL (0.3-1.12) and shifted Ca  +   2 concentration curves to the right, similar to verapamil, suggesting spasmolytic activity mediated possibly through Ca  +   2 channel blockade. In summary, the data indicated the presence of seven different phytoconstituents in the essential oil of P. guajava and calcium channel blocking activity, which provides a pharmacological base to the traditional use of P. guajava in cardiovascular and gastrointestinal disorders. Further studies are suggested to explore the molecular nature of these effects.

Factors Influencing TCE Anaerobic Dechlorination Investigated via Simulations of Microcosm Experiments

Science.gov (United States)

Mao, X.; Harkness, M.; Lee, M. D.; Mack, E. E.; Dworatzek, S.; Acheson, C.; McCarty, P.; Barry, D. A.; Gerhard, J. I.

2006-12-01

SABRE (Source Area BioREmediation) is a public-private consortium whose charter is to determine if enhanced anaerobic bioremediation can result in effective and quantifiable treatment of chlorinated solvent DNAPL source areas. The focus of this 4-year, $5.7 million research project is a field site in the United Kingdom containing a TCE DNAPL source area. In preparation, a microcosm study was performed to determine the optimal combination of factors to support reductive dechlorination of TCE in site soil and groundwater. The study consisted of 168 bottles distributed between four laboratories (Dupont, GE, SiREM, and Terra Systems) and tested the impact of six carbon substrates (lactate, acetate, methanol, SRS (soybean oil), hexanol, butyl acetate), bioaugmentation with KB-1 bacterial culture, three TCE levels (100 mg/L, 400 mg/L, and 800 mg/L) and two sulphate levels (200 mg/L, >500 mg/L) on TCE dechlorination. This research presents a numerical model designed to simulate the main processes occurring in the microcosms, including substrate fermentation, sequential dechlorination, toxic inhibition, and the influence of sulphate concentration. In calibrating the model to over 60 of the microcosm experiments, lumped parameters were employed to quantify the effect of key factors on the conversion rate of each chlorinated ethene in the TCE degradation sequence. Results quantify the benefit (i.e., increased stepwise dechlorination rate) due to both bioaugmentation and the presence of higher sulphate concentrations. Competitive inhibition is found to increase in significance as TCE concentrations increase; however, inclusion of Haldane inhibition is not supported. Over a wide range of experimental conditions and dechlorination steps, SRS appears to induce relatively little hydrogen limitation, thereby facilitating relatively quick conversion of TCE to ethene. In general, hydrogen limitation is found to increase with increasing TCE concentration and with bioaugmentation, and

Polyvinyl alcohol-immobilized Phanerochaete chrysosporium and its application in the bioremediation of composite-polluted wastewater

Energy Technology Data Exchange (ETDEWEB)

Huang, Zhenzhen [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Chen, Guiqiu, E-mail: gqchen@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Chen, Anwei [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Zuo, Yanan; Guo, Zhi; Tan, Qiong [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Song, Zhongxian [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500 (China); Niu, Qiuya [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

2015-05-30

Graphical abstract: Schematic diagram of polyvinyl alcohol-immobilized Phanerochaete chrysosporium beads (PPBs) for Cd(II) removal and 2,4-DCP degradation. - Highlights: • PVA-immobilized P. chrysosporium beads (PPBs) were fit for wastewater treatment. • Removal rates of Cd(II) and 2,4-DCP at optimum conditions were up to 78% and 95.4%. • 2,4-DCP removal rates were beyond 90% with varying initial 2,4-DCP concentrations. • PVA was vital to Cd(II) removal besides the function groups in P. chrysosporium. • Maximum recovery of the Cd(II)-laden PPBs after reuse three times was 98.9%. - Abstract: A novel biosorbent, polyvinyl alcohol (PVA)-immobilized Phanerochaete chrysosporium, was applied to the bioremediation of composite-polluted wastewater, containing both cadmium and 2,4-dichlorophenol (2,4-DCP). The optimum removal efficiency achieved was 78% for Cd(II) and 95.4% for 2,4-DCP at initial concentrations of 20 mg/L Cd(II) and 40 mg/L 2,4-DCP. PPBs had significantly enhanced the resistance of P. chrysosporium to 2,4-DCP, leading to the degradation rates of 2,4-DCP beyond 90% with varying initial 2,4-DCP concentrations. This research demonstrated that 2,4-DCP and secreted proteins might be used as carbon and nitrogen sources by PVA-immobilized P. chrysosporium beads (PPBs) for Cd(II) removal. Fourier transform infrared spectroscopy analysis showed that hydroxyl and carboxyl groups on the surface of PPBs were dominant in Cd(II) binding. The mechanism underlying the degradation of 2,4-DCP into fumaric acid and 1-hexanol was investigated. The adsorption–desorption studies indicated that PPBs kept up to 98.9% of desorption efficiency over three cycles.

Fabrication of novel nanoporous array anodic alumina solid-phase microextraction fiber coating and its potential application for headspace sampling of biological volatile organic compounds

International Nuclear Information System (INIS)

Zhang Zhuomin; Wang Qingtang; Li Gongke

2012-01-01

Highlights: ► Nanoporous array anodic alumina (NAAA) SPME coating was originally prepared. ► NAAA SPME coating achieved excellent enrichment capability and selectivity for VOCs. ► NAAA SPME coating can be applied for the headspace sampling of biological VOCs. - Abstract: In the study, nanoporous array anodic alumina (NAAA) prepared by a simple, rapid and stable two-step anodic oxidization method was introduced as a novel solid-phase microextraction (SPME) fiber coating. The regular nanoporous array structure and chemical composition of NAAA SPME fiber coating was characterized and validated by scanning electron microscopy and energy dispersive spectroscopy, respectively. Compared with the commercial polydimethylsiloxane (PDMS) SPME fiber coating, NAAA SPME fiber coating achieved the higher enrichment capability (1.7–4.7 folds) for the mixed standards of volatile organic compounds (VOCs). The selectivity for volatile alcohols by NAAA SPME fiber coating demonstrated an increasing trend with the increasing polarity of alcohols caused by the gradually shortening carbon chains from 1-undecanol to 1-heptanol or the isomerization of carbon chains of some typical volatile alcohols including 2-ethyl hexanol, 1-octanol, 2-phenylethanol, 1-phenylethanol, 5-undecanol, 2-undecanol and 1-undecanol. Finally, NAAA SPME fiber coating was originally applied for the analysis of biological VOCs of Bailan flower, stinkbug and orange peel samples coupled with gas chromatography–mass spectrometry (GC–MS) detection. Thirty, twenty-seven and forty-four VOCs of Bailan flower, stinkbug and orange peel samples were sampled and identified, respectively. Moreover, the contents of trace 1-octanol and nonanal of real orange peel samples were quantified for the further method validation with satisfactory recoveries of 106.5 and 120.5%, respectively. This work proposed a sensitive, rapid, reliable and convenient analytical method for the potential study of trace and small molecular

Identification and field evaluation of fermentation volatiles from wine and vinegar that mediate attraction of spotted wing Drosophila, Drosophila suzukii.

Science.gov (United States)

Cha, Dong H; Adams, Todd; Rogg, Helmuth; Landolt, Peter J

2012-11-01

Previous studies suggest that olfactory cues from damaged and fermented fruits play important roles in resource recognition of polyphagous spotted wing Drosophila flies (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). They are attracted to fermented sweet materials, such as decomposing fruits but also wines and vinegars, and to ubiquitous fermentation volatiles, such as acetic acid and ethanol. Gas chromatography coupled with electroantennographic detection (GC-EAD), gas chromatography-mass spectrometry (GC-MS), two-choice laboratory bioassays, and field trapping experiments were used to identify volatile compounds from wine and vinegar that are involved in SWD attraction. In addition to acetic acid and ethanol, consistent EAD responses were obtained for 13 volatile wine compounds and seven volatile vinegar compounds, with all of the vinegar EAD-active compounds also present in wine. In a field trapping experiment, the 9-component vinegar blend and 15-component wine blend were similarly attractive when compared to an acetic acid plus ethanol mixture, but were not as attractive as the wine plus vinegar mixture. In two-choice laboratory bioassays, 7 EAD-active compounds (ethyl acetate, ethyl butyrate, ethyl lactate, 1-hexanol, isoamyl acetate, 2-methylbutyl acetate, and ethyl sorbate), when added singly to the mixture at the same concentrations tested in the field, decreased the attraction of SWD to the mixture of acetic acid and ethanol. The blends composed of the remaining EAD-active chemicals, an 8-component wine blend [acetic acid + ethanol + acetoin + grape butyrate + methionol + isoamyl lactate + 2-phenylethanol + diethyl succinate] and a 5-component vinegar blend [acetic acid + ethanol + acetoin + grape butyrate + 2-phenylethanol] were more attractive than the acetic acid plus ethanol mixture, and as attractive as the wine plus vinegar mixture in both laboratory assays and the field trapping experiment. These results indicate that these

Use of solid phase microextraction to identify volatile organic compounds in brazilian wines from different grape varieties

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Natália Cristina Morais Fernandes

Full Text Available Abstract The Brazilian wine industry has shown significant growth in recent years and the insertion of new concepts, such as geographical indications as signs of quality, has placed Brazil in tune with the tendencies of world wine production. The aim of this work was to apply the Solid Phase Microextraction technique in combination with Gas Chromatography-Mass Spectrometry to study Brazilian wines made from different grape varieties, in order to separate and identify their volatile organic compounds. These substances were identified by comparisons between the spectra obtained with those presented in the NIST library database, and by comparisons with linear retention indices and literature data. The amounts of the compounds were calculated based on the total peak areas of the chromatograms. Forty-seven volatile compounds were identified and grouped into alcohols, aldehydes, fatty acids, esters, hydrocarbons, ketones and terpenes. Most of them belonged to the ester function, conferring a fruity aroma on the wines. The alcohols may have originated from the yeast metabolism, contributing to the alcoholic and floral aromas. Ethyl lactate, 1-hexanol and diethyl maleate were identified in all the varieties, except Merlot. Decanal, methyl citronellate, (E-2-hexenyl-3-methylbutyrate were only found in Merlot, while 2,3-butanediol was only present in the Tannat wines. 2-Phenylethanol was present in all varieties and is recognized as giving pleasant rose and honey attributes to wines. This study showed that the volatile profile of red wines is mainly characterized by esters and higher alcohols. The statistical analysis of the comparison of averages showed a greater amount of averages significantly different in the relative areas of Merlot wine. The Principal Component Analysis showed one grouping composed only of the Merlot wine samples, and this was probably related to the existence of the volatile organic compounds that were specifically identified in

Various Bee Pheromones Binding Affinity, Exclusive Chemosensillar Localization, and Key Amino Acid Sites Reveal the Distinctive Characteristics of Odorant-Binding Protein 11 in the Eastern Honey Bee, Apis cerana.

Science.gov (United States)

Song, Xin-Mi; Zhang, Lin-Ya; Fu, Xiao-Bin; Wu, Fan; Tan, Jing; Li, Hong-Liang

2018-01-01

Odorant-binding proteins (OBPs) are the critical elements responsible for binding and transporting odors and pheromones in the sensitive olfactory system in insects. Honey bees are representative social insects that have complex odorants and pheromone communication systems relative to solitary insects. Here, we first cloned and characterized OBP11 ( AcerOBP11 ), from the worker bees antennae of Eastern honey bee, Apis cerana . Based on sequence and phylogenetic analysis, most sequences homologous to AcerOBP11 belong to the typical OBPs family. The transcriptional expression profiles showed that AcerOBP11 was expressed throughout the developmental stages and highly specifically expressed in adult antennae. Using immunofluorescence localization, AcerOBP11 in worker bee's antennae was only localized in the sensilla basiconica (SB) near the fringe of each segment. Fluorescence ligand-binding assay showed that AcerOBP11 protein had strong binding affinity with the tested various bee pheromones components, including the main queen mandibular pheromones (QMPs), methyl p-hydroxybenzoate (HOB), and ( E )-9-oxo-2-decanoic acid (9-ODA), alarm pheromone (n-hexanol), and worker pheromone components. AcerOBP11 also had strong binding affinity to plant volatiles, such as 4-Allylveratrole. Based on the docking and site-directed mutagenesis, two key amino acid residues (Ile97 and Ile140) were involved in the binding of AcerOBP11 to various bee pheromones. Taken together, we identified that AcerOBP11 was localized in a single type of antennal chemosensilla and had complex ligand-binding properties, which confer the dual-role with the primary characteristics of sensing various bee pheromones and secondary characteristics of sensing general odorants. This study not only prompts the theoretical basis of OBPs-mediated bee pheromones recognition of honey bee, but also extends the understanding of differences in pheromone communication between social and solitary insects.

Various Bee Pheromones Binding Affinity, Exclusive Chemosensillar Localization, and Key Amino Acid Sites Reveal the Distinctive Characteristics of Odorant-Binding Protein 11 in the Eastern Honey Bee, Apis cerana

Directory of Open Access Journals (Sweden)

Xin-Mi Song

2018-04-01

Full Text Available Odorant-binding proteins (OBPs are the critical elements responsible for binding and transporting odors and pheromones in the sensitive olfactory system in insects. Honey bees are representative social insects that have complex odorants and pheromone communication systems relative to solitary insects. Here, we first cloned and characterized OBP11 (AcerOBP11, from the worker bees antennae of Eastern honey bee, Apis cerana. Based on sequence and phylogenetic analysis, most sequences homologous to AcerOBP11 belong to the typical OBPs family. The transcriptional expression profiles showed that AcerOBP11 was expressed throughout the developmental stages and highly specifically expressed in adult antennae. Using immunofluorescence localization, AcerOBP11 in worker bee's antennae was only localized in the sensilla basiconica (SB near the fringe of each segment. Fluorescence ligand-binding assay showed that AcerOBP11 protein had strong binding affinity with the tested various bee pheromones components, including the main queen mandibular pheromones (QMPs, methyl p-hydroxybenzoate (HOB, and (E-9-oxo-2-decanoic acid (9-ODA, alarm pheromone (n-hexanol, and worker pheromone components. AcerOBP11 also had strong binding affinity to plant volatiles, such as 4-Allylveratrole. Based on the docking and site-directed mutagenesis, two key amino acid residues (Ile97 and Ile140 were involved in the binding of AcerOBP11 to various bee pheromones. Taken together, we identified that AcerOBP11 was localized in a single type of antennal chemosensilla and had complex ligand-binding properties, which confer the dual-role with the primary characteristics of sensing various bee pheromones and secondary characteristics of sensing general odorants. This study not only prompts the theoretical basis of OBPs-mediated bee pheromones recognition of honey bee, but also extends the understanding of differences in pheromone communication between social and solitary insects.

Impaired sense of smell in a Drosophila Parkinson's model.

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Simone Poddighe

Full Text Available Parkinson's disease (PD is one of the most common neurodegenerative disease characterized by the clinical triad: tremor, akinesia and rigidity. Several studies have suggested that PD patients show disturbances in olfaction at the earliest onset of the disease. The fruit fly Drosophila melanogaster is becoming a powerful model organism to study neurodegenerative diseases. We sought to use this system to explore olfactory dysfunction, if any, in PINK1 mutants, which is a model for PD. PINK1 mutants display many important diagnostic symptoms of the disease such as akinetic motor behavior. In the present study, we describe for the first time, to the best of our knowledge, neurophysiological and neuroanatomical results concerning the olfactory function in PINK1 mutant flies. Electroantennograms were recorded in response to synthetic and natural volatiles (essential oils from groups of PINK1 mutant adults at three different time points in their life cycle: one from 3-5 day-old flies, from 15-20 and from 27-30 days. The results obtained were compared with the same age-groups of wild type flies. We found that mutant adults showed a decrease in the olfactory response to 1-hexanol, α-pinene and essential oil volatiles. This olfactory response in mutant adults decreased even more as the flies aged. Immunohistological analysis of the antennal lobes in these mutants revealed structural abnormalities, especially in the expression of Bruchpilot protein, a marker for synaptic active zones. The combination of electrophysiological and morphological results suggests that the altered synaptic organization may be due to a neurodegenerative process. Our results indicate that this model can be used as a tool for understanding PD pathogensis and pathophysiology. These results help to explore the potential of using olfaction as a means of monitoring PD progression and developing new treatments.

Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate

Energy Technology Data Exchange (ETDEWEB)

Chow, Tina Kuo Fung [Univ. of California, Berkeley, CA (United States)

1992-05-01

The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25°C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB^-, with all complexes containing only one NPB^- per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH)₄^- (aq.), i.e. the complexation constants increase with increasing number of -OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB^-) at higher concentrations. The -OH group on the NPB^- which is left uncomplexed after one solute molecule had bound to the other two -OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA⁺ can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB^-. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.

Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate. [1,2-propanediol

Energy Technology Data Exchange (ETDEWEB)

Chow, Tina Kuo Fung.

1992-05-01

The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25{degree}C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB{sup {minus}}, with all complexes containing only one NPB{sup {minus}} per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH){sub 4}{sup {minus}} (aq.), i.e. the complexation constants increase with increasing number of {minus}OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB{sup {minus}}) at higher concentrations. The {minus}OH group on the NPB{sup {minus}} which is left uncomplexed after one solute molecule had bound to the other two {minus}OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA{sup +} can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB{sup {minus}}. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.

Fabrication of novel nanoporous array anodic alumina solid-phase microextraction fiber coating and its potential application for headspace sampling of biological volatile organic compounds

Energy Technology Data Exchange (ETDEWEB)

Zhang Zhuomin [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Wang Qingtang [Key Laboratory of Analysis and Detection for Food Safety of Ministry of Education, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350002 (China); Li Gongke, E-mail: cesgkl@mail.sysu.edu.cn [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

2012-05-21

Highlights: Black-Right-Pointing-Pointer Nanoporous array anodic alumina (NAAA) SPME coating was originally prepared. Black-Right-Pointing-Pointer NAAA SPME coating achieved excellent enrichment capability and selectivity for VOCs. Black-Right-Pointing-Pointer NAAA SPME coating can be applied for the headspace sampling of biological VOCs. - Abstract: In the study, nanoporous array anodic alumina (NAAA) prepared by a simple, rapid and stable two-step anodic oxidization method was introduced as a novel solid-phase microextraction (SPME) fiber coating. The regular nanoporous array structure and chemical composition of NAAA SPME fiber coating was characterized and validated by scanning electron microscopy and energy dispersive spectroscopy, respectively. Compared with the commercial polydimethylsiloxane (PDMS) SPME fiber coating, NAAA SPME fiber coating achieved the higher enrichment capability (1.7-4.7 folds) for the mixed standards of volatile organic compounds (VOCs). The selectivity for volatile alcohols by NAAA SPME fiber coating demonstrated an increasing trend with the increasing polarity of alcohols caused by the gradually shortening carbon chains from 1-undecanol to 1-heptanol or the isomerization of carbon chains of some typical volatile alcohols including 2-ethyl hexanol, 1-octanol, 2-phenylethanol, 1-phenylethanol, 5-undecanol, 2-undecanol and 1-undecanol. Finally, NAAA SPME fiber coating was originally applied for the analysis of biological VOCs of Bailan flower, stinkbug and orange peel samples coupled with gas chromatography-mass spectrometry (GC-MS) detection. Thirty, twenty-seven and forty-four VOCs of Bailan flower, stinkbug and orange peel samples were sampled and identified, respectively. Moreover, the contents of trace 1-octanol and nonanal of real orange peel samples were quantified for the further method validation with satisfactory recoveries of 106.5 and 120.5%, respectively. This work proposed a sensitive, rapid, reliable and convenient

[Indoor air pollution by volatile organic compounds in large buildings: pollution levels and remaining issues after revision of the Act on Maintenance of Sanitation in Buildings in 2002].

Science.gov (United States)

Sakai, Kiyoshi; Kamijima, Michihiro; Shibata, Eiji; Ohno, Hiroyuki; Nakajima, Tamie

2010-09-01

This study aimed to clarify indoor air pollution levels of volatile organic compounds (VOCs), especially 2-ethyl-1-hexanol (2E1H) in large buildings after revising of the Act on Maintenance of Sanitation in Buildings in 2002. We measured indoor air VOC concentrations in 57 (97%) out of a total of 61 large buildings completed within one year in half of the area of Nagoya, Japan, from 2003 through 2007. Airborne concentrations of 13 carbonyl compounds were determined with diffusion samplers and high-performance liquid chromatography, and of the other 32 VOCs with diffusion samplers and gas chromatography with a mass spectrometer. Formaldehyde was detected in all samples of indoor air but the concentrations were lower than the indoor air quality standard value set in Japan (100 microg/m3). Geometric mean concentrations of the other major VOCs, namely toluene, xylene, ethylbenzene, styrene, p-dichlorobenzene and acetaldehyde were also low. 2E1H was found to be one of the predominating VOCs in indoor air of large buildings. A few rooms in a small number of buildings surveyed showed high concentrations of 2E1H, while low concentrations were observed in most rooms of those buildings as well as in other buildings. It was estimated that about 310 buildings had high indoor air pollution levels of 2E1H, with increase during the 5 years from 2003 in Japan. Indoor air pollution levels of VOCs in new large buildings are generally good, although a few rooms in a small number of buildings showed high concentrations in 2E1H, a possible causative chemical in sick building symptoms. Therefore, 2E1H needs particular attention as an important indoor air pollutant.

Electrochemical genoassays on gold-coated magnetic nanoparticles to quantify genetically modified organisms (GMOs) in food and feed as GMO percentage.

Science.gov (United States)

Plácido, Alexandra; Pereira, Clara; Guedes, Alexandra; Barroso, M Fátima; Miranda-Castro, Rebeca; de-Los-Santos-Álvarez, Noemí; Delerue-Matos, Cristina

2018-07-01

The integration of nanomaterials in the field of (bio)sensors has allowed developing strategies with improved analytical performance. In this work, ultrasmall core-shell Fe 3 O 4 @Au magnetic nanoparticles (MNPs) were used as the platform for the immobilization of event-specific Roundup Ready (RR) soybean and taxon-specific DNA sequences. Firstly, monodisperse Fe 3 O 4 MNPs were synthesized by thermal decomposition and subsequently coated with a gold shell through reduction of Au(III) precursor on the surface of the MNPs in the presence of an organic capping agent. This nanosupport exhibited high colloidal stability, average particle size of 10.2 ± 1.3 nm, and spherical shape. The covalent immobilization of ssDNA probe onto the Au shell of the Fe 3 O 4 @Au MNPs was achieved through a self-assembled monolayer (SAM) created from mixtures of alkane thiols (6-mercapto-1-hexanol and mercaptohexanoic acid). The influence of the thiols ratio on the electrochemical performance of the resulting electrochemical genoassays was studied, and remarkably, the best analytical performance was achieved for a pure mercaptohexanoic acid SAM. Two quantification assays were designed; one targeting an RR sequence and a second targeting a reference soybean gene, both with a sandwich format for hybridization, signaling probes labelled with fluorescein isothiocyanate (FITC), enzymatic amplification and chronoamperometric detection at screen-printed carbon electrodes (SPCE). The magnetogenoassays exhibited linear ranges from 0.1 to 10.0 nM and from 0.1 to 5.0 nM with similar detection limits of 0.02 nM and 0.05 nM for the event-specific (RR) and the taxon-specific (lectin) targets, respectively. The usefulness of the approach was demonstrated by its application to detect genetically modified organisms (GMOs) in feed and food. Copyright © 2018 Elsevier B.V. All rights reserved.

Mucuna pruriens (Velvet bean) rescues motor, olfactory, mitochondrial and synaptic impairment in PINK1B9 Drosophila melanogaster genetic model of Parkinson's disease.

Science.gov (United States)

Poddighe, Simone; De Rose, Francescaelena; Marotta, Roberto; Ruffilli, Roberta; Fanti, Maura; Secci, Pietro Paolo; Mostallino, Maria Cristina; Setzu, Maria Dolores; Zuncheddu, Maria Antonietta; Collu, Ignazio; Solla, Paolo; Marrosu, Francesco; Kasture, Sanjay; Acquas, Elio; Liscia, Anna

2014-01-01

The fruit fly Drosophila melanogaster (Dm) mutant for PTEN-induced putative kinase 1 (PINK1B9) gene is a powerful tool to investigate physiopathology of Parkinson's disease (PD). Using PINK1B9 mutant Dm we sought to explore the effects of Mucuna pruriens methanolic extract (Mpe), a L-Dopa-containing herbal remedy of PD. The effects of Mpe on PINK1B9 mutants, supplied with standard diet to larvae and adults, were assayed on 3-6 (I), 10-15 (II) and 20-25 (III) days old flies. Mpe 0.1% significantly extended lifespan of PINK1B9 and fully rescued olfactory response to 1-hexanol and improved climbing behavior of PINK1B9 of all ages; in contrast, L-Dopa (0.01%, percentage at which it is present in Mpe 0.1%) ameliorated climbing of only PINK1B9 flies of age step II. Transmission electron microscopy analysis of antennal lobes and thoracic ganglia of PINK1B9 revealed that Mpe restored to wild type (WT) levels both T-bars and damaged mitochondria. Western blot analysis of whole brain showed that Mpe, but not L-Dopa on its own, restored bruchpilot (BRP) and tyrosine hydroxylase (TH) expression to age-matched WT control levels. These results highlight multiple sites of action of Mpe, suggesting that its effects cannot only depend upon its L-Dopa content and support the clinical observation of Mpe as an effective medication with intrinsic ability of delaying the onset of chronic L-Dopa-induced long-term motor complications. Overall, this study strengthens the relevance of using PINK1B9 Dm as a translational model to study the properties of Mucuna pruriens for PD treatment.

Mucuna pruriens (Velvet bean) Rescues Motor, Olfactory, Mitochondrial and Synaptic Impairment in PINK1B9 Drosophila melanogaster Genetic Model of Parkinson’s Disease

Science.gov (United States)

Ruffilli, Roberta; Fanti, Maura; Secci, Pietro Paolo; Mostallino, Maria Cristina; Setzu, Maria Dolores; Zuncheddu, Maria Antonietta; Collu, Ignazio; Solla, Paolo; Marrosu, Francesco; Kasture, Sanjay; Acquas, Elio; Liscia, Anna

2014-01-01

The fruit fly Drosophila melanogaster (Dm) mutant for PTEN-induced putative kinase 1 (PINK1B9) gene is a powerful tool to investigate physiopathology of Parkinson's disease (PD). Using PINK1B9 mutant Dm we sought to explore the effects of Mucuna pruriens methanolic extract (Mpe), a L-Dopa-containing herbal remedy of PD. The effects of Mpe on PINK1B9 mutants, supplied with standard diet to larvae and adults, were assayed on 3–6 (I), 10–15 (II) and 20–25 (III) days old flies. Mpe 0.1% significantly extended lifespan of PINK1B9 and fully rescued olfactory response to 1-hexanol and improved climbing behavior of PINK1B9 of all ages; in contrast, L-Dopa (0.01%, percentage at which it is present in Mpe 0.1%) ameliorated climbing of only PINK1B9 flies of age step II. Transmission electron microscopy analysis of antennal lobes and thoracic ganglia of PINK1B9 revealed that Mpe restored to wild type (WT) levels both T-bars and damaged mitochondria. Western blot analysis of whole brain showed that Mpe, but not L-Dopa on its own, restored bruchpilot (BRP) and tyrosine hydroxylase (TH) expression to age-matched WT control levels. These results highlight multiple sites of action of Mpe, suggesting that its effects cannot only depend upon its L-Dopa content and support the clinical observation of Mpe as an effective medication with intrinsic ability of delaying the onset of chronic L-Dopa-induced long-term motor complications. Overall, this study strengthens the relevance of using PINK1B9 Dm as a translational model to study the properties of Mucuna pruriens for PD treatment. PMID:25340511

Mucuna pruriens (Velvet bean rescues motor, olfactory, mitochondrial and synaptic impairment in PINK1B9 Drosophila melanogaster genetic model of Parkinson's disease.

Directory of Open Access Journals (Sweden)

Simone Poddighe

Full Text Available The fruit fly Drosophila melanogaster (Dm mutant for PTEN-induced putative kinase 1 (PINK1B9 gene is a powerful tool to investigate physiopathology of Parkinson's disease (PD. Using PINK1B9 mutant Dm we sought to explore the effects of Mucuna pruriens methanolic extract (Mpe, a L-Dopa-containing herbal remedy of PD. The effects of Mpe on PINK1B9 mutants, supplied with standard diet to larvae and adults, were assayed on 3-6 (I, 10-15 (II and 20-25 (III days old flies. Mpe 0.1% significantly extended lifespan of PINK1B9 and fully rescued olfactory response to 1-hexanol and improved climbing behavior of PINK1B9 of all ages; in contrast, L-Dopa (0.01%, percentage at which it is present in Mpe 0.1% ameliorated climbing of only PINK1B9 flies of age step II. Transmission electron microscopy analysis of antennal lobes and thoracic ganglia of PINK1B9 revealed that Mpe restored to wild type (WT levels both T-bars and damaged mitochondria. Western blot analysis of whole brain showed that Mpe, but not L-Dopa on its own, restored bruchpilot (BRP and tyrosine hydroxylase (TH expression to age-matched WT control levels. These results highlight multiple sites of action of Mpe, suggesting that its effects cannot only depend upon its L-Dopa content and support the clinical observation of Mpe as an effective medication with intrinsic ability of delaying the onset of chronic L-Dopa-induced long-term motor complications. Overall, this study strengthens the relevance of using PINK1B9 Dm as a translational model to study the properties of Mucuna pruriens for PD treatment.

Sustained Dye Release Using Poly(urea-urethane)/Cellulose Nanocrystal Composite Microcapsules.

Science.gov (United States)

Yoo, Youngman; Martinez, Carlos; Youngblood, Jeffrey P

2017-02-14

The aim of this study is to develop methods to reinforce polymeric microspheres with cellulose nanocrystals (CNCs) to make eco-friendly microcapsules for a variety of applications such as medicines, perfumes, nutrients, pesticides, and phase change materials. Surface hydrophobization treatments for CNCs were performed by grafting poly(lactic acid) oligomers and fatty acids (FAs) to enhance the dispersion of nanoparticles in the polymeric shell. Then, a straightforward process is demonstrated to design sustained release microcapsules by the incorporation of the modified CNCs (mCNCs) in the shell structure. The combination of the mCNC dispersion with subsequent interfacial polyurea (PU) to form composite capsules as well as their morphology, composition, mechanical properties, and release rates were examined in this study. The PU microcapsules embedded with the mCNC were characterized by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The morphologies of the microcapsules were characterized by optical microscopy (OM) and scanning electron microscope (SEM). The rupture stress and failure behavior of the microcapsules were determined through single-capsule compression tests. Oil-soluble Sudan II dye solution in mineral oil was utilized as a model hydrophobic fill, representing other latent fills with low partition coefficients, and their encapsulation efficiency was measured spectroscopically. The release rates of the encapsulated dye from the microcapsules were examined spectroscopically by both ethanol and 2-ethyl-1-hexanol medium at room temperature. The concentration of released dye was determined by using UV-vis absorption spectrometry (UV-vis). The mCNC embedded poly(urea-urethane) capsules have strong and dense walls, which function as excellent barriers against leakage due to their extended diffusion path length and ensure enough mechanical strength from rupture for handling or postprocessing.

Use of Torulaspora delbrueckii Co-fermentation With Two Saccharomyces cerevisiae Strains With Different Aromatic Characteristic to Improve the Diversity of Red Wine Aroma Profile.

Science.gov (United States)

Zhang, Bo-Qin; Luan, Yu; Duan, Chang-Qing; Yan, Guo-Liang

2018-01-01

The use of selected Saccharomyces and non- Saccharomyces strains as mixed starters has advantages over pure fermentation due to achieving wine products with distinctive and diversified aroma expected by consumers. To obtain a way to improve the aroma diversity and increase the differentiation of wine product, in this study, the aromatic effect of multi-culture of indigenous Torulaspora delbrueckii ( TD 12), simultaneous and sequential inoculation with two Saccharomyces strains (indigenous icewine yeast SC 45 and commercial yeast BDX) with different enological characteristics were investigated in laboratory-scale 20 L fermenter, respectively. The results showed that T. delbrueckii co-fermented with different S. cerevisiae strain could generate diversified physicochemical and aromatic quality of wine as evidenced by PCA. Mixed fermentation of SC 45/ TD 12 produced higher contents of higher alcohol (3-methyl-1-pentanol and phenylethyl alcohol), ethyl esters (ethyl decanoate and ethyl butanoate), terpenes and phenylacetaldehyde with less fatty acids (hexanoic acid, octanoic acid) and acetic acid, while BDX/ TD 12 generated more C 6 alcohol (1-hexanol) and acetate esters (ethyl acetate and isoamyl acetate). Compared to simultaneous inoculation, sequential inoculation could achieve higher aroma diversity, and generate higher intensity of fruity, flowery and sweet attributes of wine as assessed by calculating the odor activity values. The different S. cerevisiae strain and inoculation method in alcoholic fermentation could further influence the formations of aromatic compounds in malolactic fermentation. Our results highlighted the importance of S. cerevisiae strain in shaping the aromatic quality of wine in mixed fermentation, and also suggested that using different S. cerevisiae strains with distinct aromatic characteristics co-fermentation with specific non- Saccharomyces strain is a potential way to increase the aromatic diversity and quality of wine product, which

Aqueous zymography screening of matrix metalloproteinase activity and inhibition based on colorimetric gold nanoparticles.

Science.gov (United States)

Chuang, Yao-Chen; Huang, Wei-Ting; Chiang, Pin-Hsuan; Tang, Meng-Che; Lin, Chih-Sheng

2012-02-15

An optical gold nanoparticles (AuNPs)-based method was fabricated for the rapid detection of matrix metalloproteinase (MMP) activity and screening potential MMP inhibitors without sophisticated instruments. The diagnosis platform was composed of AuNPs, particular MMP substrates and 6-mercapto-1-hexanol (MCH). The functionalized AuNPs were subjected to specific MMP digestion, and the MMP found the substrate on AuNPs, such that the AuNPs lost shelter and MCH increased the attraction force between AuNPs. Consequently, AuNPs aggregation and a color change from red to purple with increasing MMP concentration were observed. The surface plasmon resonance (SPR) of the formed AuNPs allowed for the quantitative detection of MMP activity. A sensitive linear correlation existed between the absorbance and the activity of the MMPs, which ranged from 10 ng/mL to 700 ng/mL in NTTC buffer and plasma samples. The proposed colorimetric method could be accomplished in a homogeneous solution with one-step operation in 30 min and has been successfully applied to the determination of particular MMP activity in plasma samples, in which the results are consistent with substrate zymography. This technology may become a simple platform for parallel screening a number of inhibitors and offer an alternative method to studying the efficiency of inhibitors for suppressing MMP activity. The absorbance ratio at 625 nm and 525 nm (A(625)/A(525)) confirmed the efficiency of the inhibitors as observed in substrate zymography. The IC(50) of ONO-4817 and galardin for MMP-1, MMP-2 and MMP-7 determined by the proposed colorimetric method was similar to the results of substrate zymography. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Differences in volatile profiles of Cabernet Sauvignon grapes grown in two distinct regions of China and their responses to weather conditions.

Science.gov (United States)

Xu, Xiao-Qing; Liu, Bin; Zhu, Bao-Qing; Lan, Yi-Bin; Gao, Yuan; Wang, Dong; Reeves, Malcolm J; Duan, Chang-Qing

2015-04-01

Volatile compounds are considered important for plants to communicate with each other and interact with their environments. Most wine-producing regions in China feature a continental monsoon climate with hot-wet summers and dry-cold winters, giving grapes markedly different growing environments compared to the Mediterranean or oceanic climates described in previous reports. This study focused on comparing the volatile profiles of Vitis vinifera L. cv. Cabernet Sauvignon berries from two regions with distinct climate characteristics: Changli has a warm and semi-humid summer, and Gaotai has a cool-arid summer and a cold winter. The relationship between meteorological metrics and the concentrations of grape volatiles were also examined. In harvested grapes, benzyl alcohol, phenylethyl alcohol, 1-hexanol and 1-octen-3-ol were more abundant in the Changli berries, while hexanal, heptanal, 2-methoxy-3-isobutylpyrazine, and (E)-β-damascenone presented higher levels in the Gaotai berries. The fluctuation in the accumulation of volatile compounds observed during berry development was closely correlated with variations in short-term weather (weather in a week), especially rainfall. The concentration of some volatiles, notably aliphatic aldehydes, was significantly related to diurnal temperature differences. The variability during berry development of concentrations for compounds such as C6 volatile compounds, 2-methoxy-3-isobutylpyrazine and (E)-β-damascenone strongly depended upon weather conditions. This work expands our knowledge about the influence of continental monsoon climates on volatile compounds in developing grape berries. It will also improve the comprehension of the plant response to their surrounding environments through the accumulation of volatiles. The results will help growers to alter viticultural practices according to local conditions to improve the aromatic quality of grapes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Polyvinyl alcohol-immobilized Phanerochaete chrysosporium and its application in the bioremediation of composite-polluted wastewater

International Nuclear Information System (INIS)

Huang, Zhenzhen; Chen, Guiqiu; Zeng, Guangming; Chen, Anwei; Zuo, Yanan; Guo, Zhi; Tan, Qiong; Song, Zhongxian; Niu, Qiuya

2015-01-01

Graphical abstract: Schematic diagram of polyvinyl alcohol-immobilized Phanerochaete chrysosporium beads (PPBs) for Cd(II) removal and 2,4-DCP degradation. - Highlights: • PVA-immobilized P. chrysosporium beads (PPBs) were fit for wastewater treatment. • Removal rates of Cd(II) and 2,4-DCP at optimum conditions were up to 78% and 95.4%. • 2,4-DCP removal rates were beyond 90% with varying initial 2,4-DCP concentrations. • PVA was vital to Cd(II) removal besides the function groups in P. chrysosporium. • Maximum recovery of the Cd(II)-laden PPBs after reuse three times was 98.9%. - Abstract: A novel biosorbent, polyvinyl alcohol (PVA)-immobilized Phanerochaete chrysosporium, was applied to the bioremediation of composite-polluted wastewater, containing both cadmium and 2,4-dichlorophenol (2,4-DCP). The optimum removal efficiency achieved was 78% for Cd(II) and 95.4% for 2,4-DCP at initial concentrations of 20 mg/L Cd(II) and 40 mg/L 2,4-DCP. PPBs had significantly enhanced the resistance of P. chrysosporium to 2,4-DCP, leading to the degradation rates of 2,4-DCP beyond 90% with varying initial 2,4-DCP concentrations. This research demonstrated that 2,4-DCP and secreted proteins might be used as carbon and nitrogen sources by PVA-immobilized P. chrysosporium beads (PPBs) for Cd(II) removal. Fourier transform infrared spectroscopy analysis showed that hydroxyl and carboxyl groups on the surface of PPBs were dominant in Cd(II) binding. The mechanism underlying the degradation of 2,4-DCP into fumaric acid and 1-hexanol was investigated. The adsorption–desorption studies indicated that PPBs kept up to 98.9% of desorption efficiency over three cycles

Use of Torulaspora delbrueckii Co-fermentation With Two Saccharomyces cerevisiae Strains With Different Aromatic Characteristic to Improve the Diversity of Red Wine Aroma Profile

Directory of Open Access Journals (Sweden)

Bo-Qin Zhang

2018-04-01

Full Text Available The use of selected Saccharomyces and non-Saccharomyces strains as mixed starters has advantages over pure fermentation due to achieving wine products with distinctive and diversified aroma expected by consumers. To obtain a way to improve the aroma diversity and increase the differentiation of wine product, in this study, the aromatic effect of multi-culture of indigenous Torulaspora delbrueckii (TD12, simultaneous and sequential inoculation with two Saccharomyces strains (indigenous icewine yeast SC45 and commercial yeast BDX with different enological characteristics were investigated in laboratory-scale 20 L fermenter, respectively. The results showed that T. delbrueckii co-fermented with different S. cerevisiae strain could generate diversified physicochemical and aromatic quality of wine as evidenced by PCA. Mixed fermentation of SC45/TD12 produced higher contents of higher alcohol (3-methyl-1-pentanol and phenylethyl alcohol, ethyl esters (ethyl decanoate and ethyl butanoate, terpenes and phenylacetaldehyde with less fatty acids (hexanoic acid, octanoic acid and acetic acid, while BDX/TD12 generated more C6 alcohol (1-hexanol and acetate esters (ethyl acetate and isoamyl acetate. Compared to simultaneous inoculation, sequential inoculation could achieve higher aroma diversity, and generate higher intensity of fruity, flowery and sweet attributes of wine as assessed by calculating the odor activity values. The different S. cerevisiae strain and inoculation method in alcoholic fermentation could further influence the formations of aromatic compounds in malolactic fermentation. Our results highlighted the importance of S. cerevisiae strain in shaping the aromatic quality of wine in mixed fermentation, and also suggested that using different S. cerevisiae strains with distinct aromatic characteristics co-fermentation with specific non-Saccharomyces strain is a potential way to increase the aromatic diversity and quality of wine product, which

Use of Torulaspora delbrueckii Co-fermentation With Two Saccharomyces cerevisiae Strains With Different Aromatic Characteristic to Improve the Diversity of Red Wine Aroma Profile

Science.gov (United States)

Zhang, Bo-Qin; Luan, Yu; Duan, Chang-Qing; Yan, Guo-Liang

2018-01-01

The use of selected Saccharomyces and non-Saccharomyces strains as mixed starters has advantages over pure fermentation due to achieving wine products with distinctive and diversified aroma expected by consumers. To obtain a way to improve the aroma diversity and increase the differentiation of wine product, in this study, the aromatic effect of multi-culture of indigenous Torulaspora delbrueckii (TD12), simultaneous and sequential inoculation with two Saccharomyces strains (indigenous icewine yeast SC45 and commercial yeast BDX) with different enological characteristics were investigated in laboratory-scale 20 L fermenter, respectively. The results showed that T. delbrueckii co-fermented with different S. cerevisiae strain could generate diversified physicochemical and aromatic quality of wine as evidenced by PCA. Mixed fermentation of SC45/TD12 produced higher contents of higher alcohol (3-methyl-1-pentanol and phenylethyl alcohol), ethyl esters (ethyl decanoate and ethyl butanoate), terpenes and phenylacetaldehyde with less fatty acids (hexanoic acid, octanoic acid) and acetic acid, while BDX/TD12 generated more C6 alcohol (1-hexanol) and acetate esters (ethyl acetate and isoamyl acetate). Compared to simultaneous inoculation, sequential inoculation could achieve higher aroma diversity, and generate higher intensity of fruity, flowery and sweet attributes of wine as assessed by calculating the odor activity values. The different S. cerevisiae strain and inoculation method in alcoholic fermentation could further influence the formations of aromatic compounds in malolactic fermentation. Our results highlighted the importance of S. cerevisiae strain in shaping the aromatic quality of wine in mixed fermentation, and also suggested that using different S. cerevisiae strains with distinct aromatic characteristics co-fermentation with specific non-Saccharomyces strain is a potential way to increase the aromatic diversity and quality of wine product, which could provide

Effects of UVA (320-400 nm) on the barrier characteristics of the skin

International Nuclear Information System (INIS)

McAuliffe, D.J.; Blank, I.H.

1991-01-01

The stratum corneum serves as the major barrier to the entrance of most molecules into the skin. In the studies presented here, the effects of UVA radiation (320-400 nm) on the barrier capacity of human stratum corneum were examined. Penetration of a homologous series of primary alcohols through unirradiated (control) and UVA-irradiated (test) human epidermis was determined in vitro. Permeability constants, kp, were calculated. Mean ratios of permeability constants for UVA-irradiated and unirradiated epidermis (mean kp test)/(mean kp control) ranged from 2.3 to 3.0 for methanol and from 2.2 to 2.5 for ethanol. These mean ratios were determined using different pieces of epidermis from the same piece of skin for test and control samples. When kp control and kp test were determined on the same piece of epidermis on successive days, the ratios (kp test/kp control) were similar to the mean ratios determined on different pieces of epidermis. For other primary alcohols, propanol, butanol, hexanol, and heptanol, UVA radiation did not alter their permeability constants significantly. Partition coefficients, Km, were determined for ethanol and heptanol using UVA-irradiated and unirradiated stratum corneum. For ethanol, irradiation resulted in a 1.5 to 2.6 times increase in Km. For heptanol, irradiation caused no change in Km. These results demonstrate that the barrier capacity of stratum corneum for small, polar, primary alcohols is diminished (permeability increases) and for higher molecular weight less polar alcohols, is unaffected by small doses of UVA radiation. This increased permeability of small polar alcohols through human skin may be due to enhanced partitioning into UVA-irradiated stratum corneum, which was not apparent for a higher molecular weight less polar alcohol

Optimisation and Characterisation of Anti-Fouling Ternary SAM Layers for Impedance-Based Aptasensors

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Anna Miodek

2015-09-01

Full Text Available An aptasensor with enhanced anti-fouling properties has been developed. As a case study, the aptasensor was designed with specificity for human thrombin. The sensing platform was developed on screen printed electrodes and is composed of a self-assembled monolayer made from a ternary mixture of 15-base thiolated DNA aptamers specific for human thrombin co-immobilised with 1,6-hexanedithiol (HDT and further passivated with 1-mercapto-6-hexanol (MCH. HDT binds to the surface by two of its thiol groups forming alkyl chain bridges and this architecture protects from non-specific attachment of molecules to the electrode surface. Using Electrochemical Impedance Spectroscopy (EIS, the aptasensor is able to detect human thrombin as variations in charge transfer resistance (Rct upon protein binding. After exposure to a high concentration of non-specific Bovine Serum Albumin (BSA solution, no changes in the Rct value were observed, highlighting the bio-fouling resistance of the surface generated. In this paper, we present the optimisation and characterisation of the aptasensor based on the ternary self-assembled monolayer (SAM layer. We show that anti-fouling properties depend on the type of gold surface used for biosensor construction, which was also confirmed by contact angle measurements. We further studied the ratio between aptamers and HDT, which can determine the specificity and selectivity of the sensing layer. We also report the influence of buffer pH and temperature used for incubation of electrodes with proteins on detection and anti-fouling properties. Finally, the stability of the aptasensor was studied by storage of modified electrodes for up to 28 days in different buffers and atmospheric conditions. Aptasensors based on ternary SAM layers are highly promising for clinical applications for detection of a range of proteins in real biological samples.

Organic Compounds Complexify Transport in the Amargosa Desert—The Case for Phytotritiation

Science.gov (United States)

Stonestrom, D. A.; Luo, W.; Andraski, B. J.; Baker, R. J.; Maples, S.; Mayers, C. J.; Young, M. B.

2014-12-01

Civilian low-level radioactive waste containing organic compounds was disposed in 2- to 15-m deep unlined trenches in a 110-m deep unsaturated zone at the present-day USGS Amargosa Desert Research Site. Tritium represents the plurality of disposed activity. A plume of gas-phase contaminants surrounds the disposal area, with 60 distinct volatile organic compounds (VOCs) identified to date. The distribution of tritiated water in the unsaturated zone surrounding the disposal area is highly enigmatic, with orders of magnitude separating observed levels from those predicted by multiphase models of mass and energy transport. Peaks of tritium and VOCs are coincidently located in sediments tens of meters below the root zone, suggesting abiotic stratigraphic control on lateral transport at depth. Surprisingly, the highest observed levels of tritium occur at a depth of about 1.5 m, the base of the creosote-bush plant-community root zone, where levels of waste-derived VOCs are low (approaching atmospheric levels). Bulk water-vapor samples from shallow and deep unsaturated-zone profile hot spots were trapped as water ice in cold fingers immersed in dry ice-isopropyl alcohol filled Dewar flasks, then melted and sequentially extracted by purge-and-trap VOC degassing followed by elution through activated carbon solid-phase extraction (SPE) cartridges. Analysis of tritium activities and mass spectrometer results indicate that over 98% of tritium activity at depth is present as water, whereas about 15% of basal root zone tritium activity is present as organic compounds trapped with the water. Of these, the less-volatile compound group removed by SPE accounted for about 85% of the organic tritium activity, with mass spectrometry identifying 2-ethyl-1-hexanol as the principal compound removed. This plant-produced fatty alcohol is ubiquitous in the root zone of creosote-bush communities and represents a family of hydroxyl-containing plant produced compounds that give the plants their

Volatile Compounds and Sensory Profiles of Monovarietal Virgin Olive Oil from Buža, Črna and Rosinjola Cultivars in Istria (Croatia

Directory of Open Access Journals (Sweden)

Barbara Sladonja

2012-01-01

Full Text Available The volatile compounds found in virgin olive oil, mainly C6 and C5 volatile compounds biogenerated from polyunsaturated fatty acids through the lipoxygenase pathway, are responsible for their particular aroma. The composition of volatile compounds in olive oil depends on the cultivar, the ripening degree of the fruits and processing conditions. Among many different autochthonous cultivars in Istria (Croatia, some of the most prevalent are Buža, Črna and Rosinjola. The volatiles and sensory characteristics of their monovarietal virgin olive oil are little known. Therefore, fruits from these three cultivars were handpicked at the same ripening degree and processed under the same conditions. Quantitative descriptive sensory analysis of monovarietal virgin olive oil was carried out by the panel. Volatile composition was evaluated by headspace solid phase microextraction-gas chromatography, previously optimized and validated. The main parameters affecting effectiveness, time and temperature of extraction were optimized. The extraction procedure showed detection and quantification limits, as well as linear ranges adequate for the analysis of selected volatile compounds. Good precision was obtained both in terms of intra-day repeatability (relative standard deviations generally lower than 7 % and inter-day precision. The tested types of monovarietal olive oil showed different volatile profiles, although E-2-hexenal was the main compound in all samples. Buža oil was the richest in total C6 and C5 volatile compounds. The results show that the most important contributors to the olive oil aroma (odour activity value >1.0 were 1-penten-3-one, E-2-hexenal, hexanal, hexanol, Z-3-hexen-1-ol and Z-2-penten-1-ol. These chemical findings were compared with those provided by the panel test. Buža had the highest intensity of sensory characteristic 'other ripe fruits' and Rosinjola had the highest intensity of sensory characteristic 'bitter'. All results show

Evolution of potent odorants within the volatile metabolome of high-quality hazelnuts (Corylus avellana L.): evaluation by comprehensive two-dimensional gas chromatography coupled with mass spectrometry.

Science.gov (United States)

Rosso, Marta Cialiè; Liberto, Erica; Spigolon, Nicola; Fontana, Mauro; Somenzi, Marco; Bicchi, Carlo; Cordero, Chiara

2018-01-09

Within the pattern of volatiles released by food products (volatilome), potent odorants are bio-active compounds that trigger aroma perception by activating a complex array of odor receptors (ORs) in the regio olfactoria. Their informative role is fundamental to select optimal post-harvest and storage conditions and preserve food sensory quality. This study addresses the volatile metabolome from high-quality hazelnuts (Corylus avellana L.) from the Ordu region (Turkey) and Tonda Romana from Italy, and investigates its evolution throughout the production chain (post-harvest, industrial storage, roasting) to find functional correlations between technological strategies and product quality. The volatile metabolome is analyzed by headspace solid-phase microextration combined with comprehensive two-dimensional gas chromatography and mass spectrometry. Dedicated pattern recognition, based on 2D data (targeted fingerprinting), is used to mine analytical outputs, while principal component analysis (PCA), Fisher ratio, hierarchical clustering, and analysis of variance are used to find decision makers among the most informative chemicals. Low-temperature drying (18-20 °C) has a decisive effect on quality; it correlates negatively with bacteria and mold metabolic activity, nut viability, and lipid oxidation products (2-methyl-1-propanol, 3-methyl-1-butanol, 2-ethyl-1-hexanol, 2-octanol, 1-octen-3-ol, hexanal, octanal and (E)-2-heptanal). Protective atmosphere storage (99% N 2 -1% O 2 ) effectively limits lipid oxidation for 9-12 months after nut harvest. The combination of optimal drying and storage preserves the aroma potential; after roasting at different shelf-lives, key odorants responsible for malty and buttery (2- and 3-methylbutanal, 2,3-butanedione and 2,3-pentanedione), earthy (methylpyrazine, 2-ethyl-5-methyl pyrazine and 3-ethyl-2,5-dimethyl pyrazine) and caramel-like and musty notes (2,5-dimethyl-4-hydroxy-3(2H)-furanone - furaneol and acetyl pyrrole) show no

Development of a dynamic headspace solid-phase microextraction procedure coupled to GC-qMSD for evaluation the chemical profile in alcoholic beverages

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, F.; Caldeira, M. [Centro de Quimica da Madeira, Departamento de Quimica, Universidade da Madeira, Campus Universitario da Penteada, 9000-390 Funchal (Portugal); Camara, J.S. [Centro de Quimica da Madeira, Departamento de Quimica, Universidade da Madeira, Campus Universitario da Penteada, 9000-390 Funchal (Portugal)], E-mail: jsc@uma.pt

2008-02-18

In the present study, a simple and sensitive methodology based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography with quadrupole mass detection (GC-qMSD), was developed and optimized for the determination of volatile (VOCs) and semi-volatile (SVOCs) compounds from different alcoholic beverages: wine, beer and whisky. Key experimental factors influencing the equilibrium of the VOCs and SVOCs between the sample and the SPME fibre, as the type of fibre coating, extraction time and temperature, sample stirring and ionic strength, were optimized. The performance of five commercially available SPME fibres was evaluated and compared, namely polydimethylsiloxane (PDMS, 100 {mu}m); polyacrylate (PA, 85 {mu}m); polydimethylsiloxane/divinylbenzene (PDMS/DVB, 65 {mu}m); carboxen{sup TM}/polydimethylsiloxane (CAR/PDMS, 75 {mu}m) and the divinylbenzene/carboxen on polydimethylsiloxane (DVB/CAR/PDMS, 50/30 {mu}m) (StableFlex). An objective comparison among different alcoholic beverages has been established in terms of qualitative and semi-quantitative differences on volatile and semi-volatile compounds. These compounds belong to several chemical families, including higher alcohols, ethyl esters, fatty acids, higher alcohol acetates, isoamyl esters, carbonyl compounds, furanic compounds, terpenoids, C13-norisoprenoids and volatile phenols. The optimized extraction conditions and GC-qMSD, lead to the successful identification of 44 compounds in white wines, 64 in beers and 104 in whiskys. Some of these compounds were found in all of the examined beverage samples. The main components of the HS-SPME found in white wines were ethyl octanoate (46.9%), ethyl decanoate (30.3%), ethyl 9-decenoate (10.7%), ethyl hexanoate (3.1%), and isoamyl octanoate (2.7%). As for beers, the major compounds were isoamyl alcohol (11.5%), ethyl octanoate (9.1%), isoamyl acetate (8.2%), 2-ethyl-1-hexanol (5.9%), and octanoic acid (5.5%). Ethyl

Development of a dynamic headspace solid-phase microextraction procedure coupled to GC-qMSD for evaluation the chemical profile in alcoholic beverages

International Nuclear Information System (INIS)

Rodrigues, F.; Caldeira, M.; Camara, J.S.

2008-01-01

In the present study, a simple and sensitive methodology based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography with quadrupole mass detection (GC-qMSD), was developed and optimized for the determination of volatile (VOCs) and semi-volatile (SVOCs) compounds from different alcoholic beverages: wine, beer and whisky. Key experimental factors influencing the equilibrium of the VOCs and SVOCs between the sample and the SPME fibre, as the type of fibre coating, extraction time and temperature, sample stirring and ionic strength, were optimized. The performance of five commercially available SPME fibres was evaluated and compared, namely polydimethylsiloxane (PDMS, 100 μm); polyacrylate (PA, 85 μm); polydimethylsiloxane/divinylbenzene (PDMS/DVB, 65 μm); carboxen TM /polydimethylsiloxane (CAR/PDMS, 75 μm) and the divinylbenzene/carboxen on polydimethylsiloxane (DVB/CAR/PDMS, 50/30 μm) (StableFlex). An objective comparison among different alcoholic beverages has been established in terms of qualitative and semi-quantitative differences on volatile and semi-volatile compounds. These compounds belong to several chemical families, including higher alcohols, ethyl esters, fatty acids, higher alcohol acetates, isoamyl esters, carbonyl compounds, furanic compounds, terpenoids, C13-norisoprenoids and volatile phenols. The optimized extraction conditions and GC-qMSD, lead to the successful identification of 44 compounds in white wines, 64 in beers and 104 in whiskys. Some of these compounds were found in all of the examined beverage samples. The main components of the HS-SPME found in white wines were ethyl octanoate (46.9%), ethyl decanoate (30.3%), ethyl 9-decenoate (10.7%), ethyl hexanoate (3.1%), and isoamyl octanoate (2.7%). As for beers, the major compounds were isoamyl alcohol (11.5%), ethyl octanoate (9.1%), isoamyl acetate (8.2%), 2-ethyl-1-hexanol (5.9%), and octanoic acid (5.5%). Ethyl decanoate (58

Purification and characterization of an extracellular lipase from a thermophilic Rhizopus oryzae strain isolated from palm fruit.

Science.gov (United States)

Hiol; Jonzo; Rugani; Druet; Sarda; Comeau

2000-03-01

We have isolated a lipolytic strain from palm fruit that was identified as a Rhizopus oryzae. Culture conditions were optimized and highest lipase production amounting to 120 U/ml was achieved after 4 days of cultivation. The extracellular lipase was purified 1200-fold by ammonium sulfate precipitation, sulphopropyl-Sepharose chromatography, Sephadex G 75 gel filtration and a second sulphopropyl-Sepharose chromatography. The specific activity of the purified enzyme was 8800 U/mg. The lipolytic enzyme has a molecular mass of 32 kDa by SDS-polyacrylamide gel electrophoresis and gel filtration. The enzyme exhibited a single band in active polyacrylamide gel electrophoresis and its isoelectric point was 7.6. Analysis of Rhizopus oryzae lipase by RP-HPLC confirmed the homogeneity of the enzyme preparation. Determination of the N-terminal sequence over 19 amino acid residues showed a high homology with lipases of the same genus. The optimum pH for enzyme activity was 7.5. Lipase was stable in the pH range from 4.5 to 7.5. The optimum temperature for lipase activity was 35 degrees C and about 65% of its activity was retained after incubation at 45 degrees C for 30 min. The lipolytic enzyme was inhibited by Triton X100, SDS, and metal ions such as Fe(3+), Cu(2+), Hg(2+) and Fe(2+). Lipase activity against triolein was enhanced by sodium cholate or taurocholate. The purified lipase had a preference for the hydrolysis of saturated fatty acid chains (C(8)-C(18)) and a 1, 3-position specificity. It showed a good stability in organic solvents and especially in long chain-fatty alcohol. The enzyme poorly hydrolyzed triacylglycerols containing n-3 polyunsaturated fatty acids, and appeared as a suitable biocatalyst for selective esterification of sardine free fatty acids with hexanol as substrate. About 76% of sardine free fatty acids were esterified after 30 h reaction whereas 90% of docosahexaenoic acid (DHA) was recovered in the unesterified fatty acids.

Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/ITMS and GC/MSn

Science.gov (United States)

Furton, Kenneth G.; Harper, Ross J.; Perr, Jeannette M.; Almirall, Jose R.

2003-09-01

A comprehensive study and comparison is underway using biological detectors and instrumental methods for the rapid detection of ignitable liquid residues (ILR) and high explosives. Headspace solid phase microextraction (SPME) has been demonstrated to be an effective sampling method helping to identify active odor signature chemicals used by detector dogs to locate forensic specimens as well as a rapid pre-concentration technique prior to instrumental detection. Common ignitable liquids and common military and industrial explosives have been studied including trinitrotoluene, tetryl, RDX, HMX, EGDN, PETN and nitroglycerine. This study focuses on identifying volatile odor signature chemicals present, which can be used to enhance the level and reliability of detection of ILR and explosives by canines and instrumental methods. While most instrumental methods currently in use focus on particles and on parent organic compounds, which are often involatile, characteristic volatile organics are generally also present and can be exploited to enhance detection particularly for well-concealed devices. Specific examples include the volatile odor chemicals 2-ethyl-1-hexanol and cyclohexanone, which are readily available in the headspace of the high explosive composition C-4; whereas, the active chemical cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) is not. The analysis and identification of these headspace 'fingerprint' organics is followed by double-blind dog trials of the individual components using certified teams in an attempt to isolate and understand the target compounds to which dogs are sensitive. Studies to compare commonly used training aids with the actual target explosive have also been undertaken to determine their suitability and effectiveness. The optimization of solid phase microextraction (SPME) combined with ion trap mobility spectrometry (ITMS) and gas chromatography/mass spectrometry/mass spectrometry (GC/MSn) is detailed including interface development

Influence of gold nanoparticles of varying size in improving the lipase activity within cationic reverse micelles.

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Maiti, Subhabrata; Das, Dibyendu; Shome, Anshupriya; Das, Prasanta Kumar

2010-02-08

Herein, we report the effect of gold nanoparticles (GNPs) in enhancing lipase activity in reverse micelles of cetyltrimethylammonium bromide (CTAB)/water/isooctane/n-hexanol. The size and concentration of the nanoparticles were varied and their specific roles were assessed in detail. An overall enhancement of activity was observed in the GNP-doped CTAB reverse micelles. The improvement in activity becomes more prominent with increasing concentration and size of the GNPs (0-52 microM and ca. 3-30 nm, respectively). The observed highest lipase activity (k(2)=1070+/-12 cm(3) g(-1) s(-1)) in GNP-doped CTAB reverse micelles ([GNP]: 52 microm, ca. 20 nm) is 2.5-fold higher than in CTAB reverse micelles without GNPs. Improvement in the lipase activity is only specific to the GNP-doped reverse micellar media, whereas GNP deactivates and structurally deforms the enzyme in aqueous media. The reason for this activation is probably due to the formation of larger-sized reverse micelles in which the GNP acts as a polar core and the surfactants aggregate around the nanoparticle ('GNP pool') instead of only water. Lipase at the augmented interface of the GNP-doped reverse micelle showed improved activity because of enhancement in both the substrate and enzyme concentrations and increased flexibility in the lipase conformation. The extent of the activation is greater in the case of the larger-sized GNPs. A correlation has been established between the activity of lipase and its secondary structure by using circular dichroism and FTIR spectroscopic analysis. The generalized influence of GNP is verified in the reverse micelles of another surfactant, namely, cetyltripropylammonium bromide (CTPAB). TEM, dynamic light scattering (DLS), and UV/Vis spectroscopic analysis were utilized to characterize the GNPs and the organized aggregates. For the first time, CTAB-based reverse micelles have been found to be an excellent host for lipase simply by doping with appropriately sized GNPs.

Volatile profile of elderberry juice: Effect of lactic acid fermentation using L. plantarum, L. rhamnosus and L. casei strains.

Science.gov (United States)

Ricci, Annalisa; Cirlini, Martina; Levante, Alessia; Dall'Asta, Chiara; Galaverna, Gianni; Lazzi, Camilla

2018-03-01

In this study we explored, for the first time, the lactic acid fermentation of elderberry juice (EJ). A total of 15 strains isolated from dairy and plant matrices, belonging to L. plantarum, L. rhamnosus and L. casei, were used for fermentations. The volatile profile of started and unstarted EJ was characterized by HS-SPME/GC-MS technique after 48h of fermentation and 12days of storage at 4°C. All L. plantarum and L. rhamnosus strains exhibited a good capacity of growth while not all L. casei strains showed the same ability. The aromatic profile of fermented juices was characterized by the presence of 82 volatile compounds pertaining to different classes: alcohols, terpenes and norisoprenoids, organic acids, ketones and esters. Elderberry juice fermented with L. plantarum strains showed an increase of total volatile compounds after 48h while the juices fermented with L. rhamnosus and L. casei exhibited a larger increase after the storage. The highest concentration of total volatile compounds were observed in EJ fermented with L. plantarum 285 isolated from dairy product. Ketones increased in all fermented juices both after fermentation and storage and the most concentrated were acetoin and diacetyl. The organic acids were also affected by lactic acid fermentation and the most abundant acids detected in fermented juices were acetic acid and isovaleric acid. Hexanol, 3-hexen-1-ol (Z) and 2-hexen-1-ol (E) were positively influenced during dairy lactic acid bacteria strains fermentation. The most represented esters were ethyl acetate, methyl isovalerate, isoamyl isovalerate and methyl salicylate, all correlated with fruit notes. Among terpenes and norisoprenoids, β-damascenone resulted the main representative with its typical note of elderberry. Furthermore, coupling obtained data with multivariate statistical analyses, as Principal Component Analysis (PCA) and Classification Trees (CT), it was possible to relate the characteristic volatile profile of samples with

Use of microextraction by packed sorbent directly coupled to an electron ionization single quadrupole mass spectrometer as an alternative for non-separative determinations.

Science.gov (United States)

Casas Ferreira, Ana María; Moreno Cordero, Bernardo; Pérez Pavón, José Luis

2017-02-01

Sometimes it is not necessary to separate the individual compounds of a sample to resolve an analytical problem, it is enough to obtain a signal profile of the sample formed by all the components integrating it. Within this strategy, electronic noses based on the direct coupling of a headspace sampler with a mass spectrometer (HS-MS) have been proposed. Nevertheless, this coupling is not suitable for the analysis of non-volatile compounds. In order to propose an alternative to HS-MS determinations for non-volatile compounds, here we present the first 'proof of concept' use of the direct coupling of microextraction by packed sorbents (MEPS) to a mass spectrometer device using an electron ionization (EI) and a single quadrupole as ionization source and analyzer, respectively. As target compounds, a set of analytes with different physic-chemical properties were evaluated (2-ethyl-1-hexanol, styrene, 2-heptanone, among others). The use of MEPS extraction present many advantages, such as it is fast, simple, easy to automate and requires small volumes of sample and organic solvents. Moreover, MEPS cartridges are re-usable as samples can be extracted more than 100 times using the same syringe. In order to introduce into the system all the elution volume from the MEPS extraction, a programmable temperature vaporizer (PTV) is proposed as the injector device. Results obtained with the proposed methodology (MEPS-PTV/MS) were compared with the ones obtained based on the separative scheme, i.e. using gas chromatography separation (MEPS-PTV-GC/MS), and both methods provided similar results. Limits of detection were found to be between 3.26 and 146.6μgL -1 in the non-separative scheme and between 0.02 and 1.72μgL -1 when the separative methodology was used. Repeatability and reproducibility were evaluated with values below 17% in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of Biodiesel from the Oily Content of Marine Green Alga Ulva fasciata

International Nuclear Information System (INIS)

Khan, A. M.; Fatima, N.

2015-01-01

The present study is focused on the chemical transformation of oils derived from the marine green alga Ulva fasciata Delile to biodiesel. The transesterification of algal oil was performed with a variety of alcohols using Na metal and NaOH as catalysts. Transesterification of algal oil by mechanical stirring yielded significant biodiesel within an hour at 60 degree C with NaOH and at room temperature with Na metal. In addition, microwave irradiated transesterification produced significant amount of biodiesel with NaOH and Na metal within 1-5 minutes. However, reaction of sodium metal in microwave oven was highly exothermic and uncontrollable that could also damage the radiation source. The reactivity order of alcohols was found to be methanol > ethanol > benzyl alcohol > 1-propanol > 1-butanol > 1-pentanol > 1-hexanol > 2-propanol. Isopropyl alcohol was found to be least reactive due to steric hindrance. Benzyl alcohol was found to be more reactive than 1-propyl alcohol due to the electron withdrawing effect of benzene ring. The highest % conversion of FAME and FAEE were found to be 97% and 98% respectively using Na metal through mechanical stirring. Biodiesel production was confirmed by thin layer chromatography (TLC). Furthermore, the fuel properties including density, kinematics viscosity, high heating value, acid value, free fatty acid (%), cloud point and pour point of U. fasciata oil and all the esters were determined and compared with the standard limits of biodiesel. Fatty acid methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 1-pentyl and 1-hexyl esters showed the fuel properties within the biodiesel standard limits therefore all of them were considered as the substitute of biodiesel. On the other hand, the fuel properties of benzyl ester were found to be above the limits of biodiesel specifications and thus it could not be considered as biodiesel. This research article will be helpful to overcome the current challenges of energy crisis, global warming and

La consommation de propylène en Europe occidentale Propylene Consumption in Western Europe

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Barraqué M.

2006-11-01

Full Text Available Les besoins de l'Europe occidentale en propylène utilisé en pétrochimie sont actuellement de 7,4. 10 puissance 6 t/an. Au cours des prochaines années, le taux de progression moyen de la consommation devrait être de l'ordre de 1,8%/an; ainsi en 1995, la pétrochimie européenne utiliserait environ 8,7. 10 puissance 6 t de propylène. L'essentiel de la progression de cette consommation sera dû au fort accroissement de la production de polypropylène et à un degré moindre de l'oxyde de propylène, de l'isopropanol et de l'éthyl-2 hexanol. Par contre les débouchés représentés par l'acrylonitrile et le cumène resteront pratiquement stables. La consommation de propylène dans les productions de butanols devrait diminuer. La part des besoins en propylène satisfaite par les vapocraqueurs européens qui est en 1986 de 82 %, devrait être inférieure à 75 % en 1995. Il sera de plus en plus nécessaire de se tourner vers d'autres sources d'approvisionnement. En 1986 les raffineries européennes ont produit 1,05. 10 puissance 6 t de propylène utilisé en pétrochimie et les importations ont atteint 0,3. 10 puissance 6 t. En 1995 la différence entre la consommation et la production des vapocraqueurs pourrait dépasser 2,0. 10 puissance 6 t. Il semble peu probable que les unités de craquage catalytique puissent combler le déficit sauf si les rendements en propylène augmentent très notablement. On peut s'attendre à la construction de splitters propylène/propane et à une augmentation des importations. D'autre part, en raison de la tension qui risque d'apparaître sur les prix du propylène, l'intérêt de certaines voies de synthèse actuellement considérées comme non rentables pourrait augmenter; ces nouvelles voies sont : - la déshydrogénation du propane déjà considérée dans d'autres régions (Mexique, Indonésie, Malaisie; - la métathèse entre l'éthylène et les butènes-2, pouvant eux-mêmes être produits à partir d

Hot and cold water infusion aroma profiles of Hibiscus sabdariffa: fresh compared with dried.

Science.gov (United States)

Ramírez-Rodrigues, M M; Balaban, M O; Marshall, M R; Rouseff, R L

2011-03-01

Calyxes from the Roselle plant (Hibiscus sabdariffa L.) were used to prepare cold (22 °C for 4 h) and hot (98 °C for 16 min) infusions/teas from both fresh and dried forms. Aroma volatiles were extracted using static headspace SPME and analyzed using GC-MS and GC-O with 2 different columns (DB-5 and DB-Wax). Totals of 28, 25, 17, and 16 volatiles were identified using GC-MS in the dried hot extract (DHE), dried cold extract (DCE), fresh hot extract (FHE), and fresh cold extract (FCE) samples, respectively. In terms of total GC-MS peak areas DHE ≫ DCE > FHE ≫ FCE. Nonanal, decanal, octanal, and 1-octen-3-ol were among the major volatiles in all 4 beverage types. Thirteen volatiles were common to all 4 teas. Furfural and 5-methyl furfural were detected only in dried hibiscus beverages whereas linalool and 2-ethyl-1-hexanol were detected only in beverages from fresh hibiscus. In terms of aroma active volatiles, 17, 16, 13, and 10 aroma active volatiles were detected for DHE, DCE, FHE, and FCE samples, respectively. The most intense aroma volatiles were 1-octen-3-one and nonanal with a group of 4 aldehydes and 3 ketones common to all samples. Dried samples contained dramatically higher levels of lipid oxidation products such as hexanal, nonanal, and decanal. In fresh hibiscus extracts, linalool (floral, citrus) and octanal (lemon, citrus) were among the highest intensity aroma compounds but linalool was not detected in any of the dried hibiscus extracts. Hibiscus teas/infusions are one of the highest volume specialty botanical products in international commerce. The beverage is consumed for both sensory pleasure and health attributes and is prepared a number of ways throughout the world. Although color and taste attributes have been examined, little information is known about its aroma volatiles and no other study has compared extractions from both fresh and dried as well as extraction temperature differences. This is also, apparently, the first study to identify

Mesophilic and psychrotrophic bacteria from meat and their spoilage potential in vitro and in beef.

Science.gov (United States)

Ercolini, Danilo; Russo, Federica; Nasi, Antonella; Ferranti, Pasquale; Villani, Francesco

2009-04-01

Mesophilic and psychrotrophic populations from refrigerated meat were identified in this study, and the spoilage potential of microbial isolates in packaged beef was evaluated by analyzing the release of volatile organic compounds (VOC) by gas chromatography-mass spectrometry (GC/MS). Fifty mesophilic and twenty-nine psychrotrophic isolates were analyzed by random amplified polymorphic DNA-PCR, and representative strains were identified by 16S rRNA gene sequencing. Carnobacterium maltaromaticum and C. divergens were the species most frequently found in both mesophilic and psychrotrophic populations. Acinetobacter baumannii, Buttiauxella spp. and Serratia spp. were identified among the mesophilic isolates, while Pseudomonas spp. were commonly identified among the psychrotrophs. The isolates were further characterized for their growth at different temperatures and their proteolytic activity in vitro on meat proteins extracts at 7 degrees C. Selected proteolytic strains of Serratia proteamaculans, Pseudomonas fragi, and C. maltaromaticum were used to examine their spoilage potential in situ. Single strains of these species and mixtures of these strains were used to contaminate beef chops that were packed and stored at 7 degrees C. At time intervals up to 1 month, viable counts were determined, and VOC were identified by GC/MS. Generally, the VOC concentrations went to increase during the storage of the contaminated meats, and the profiles of the analyzed meat changed dramatically depending on the contaminating microbial species. About 100 volatiles were identified in the different contaminated samples. Among the detected volatiles, some specific molecules were identified only when the meat was contaminated by a specific microbial species. Compounds such as 2-ethyl-1-hexanol, 2-buten-1-ol, 2-hexyl-1-octanol, 2-nonanone, and 2-ethylhexanal were detectable only for C. maltaromaticum, which also produced the highest number of aldehydes, lactones, and sulfur compounds. The

Thermophysical properties and phase equilibria study of the binary systems {l_brace}N-hexylquinolinium bis(trifluoromethylsulfonyl)imide + aromatic hydrocarbons, or an alcohol{r_brace}

Energy Technology Data Exchange (ETDEWEB)

Domanska, Urszula, E-mail: ula@ch.pw.edu.p [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Thermodynamic Research Unit, School of Chemical Engineering, University of KwaZulu-Natal, Howard College Campus, King George V Avenue, Durban 4001 (South Africa); Zawadzki, Maciej [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Zwolinska, Magdalena [Department of Ergonomics, Laboratory of Thermal Loads, Central Institute for Labour Protection-National Research Institute, Czerniakowska 16, 00-701 Warsaw (Poland)

2011-05-15

Research highlights: We synthesized new ionic liquid, [HQuin][NTf{sub 2}] with low viscosity, and low density. We found high heat capacity, high enthalpy of melting and low melting temperature. HQuin][NTf{sub 2}] is proposed for possible use in the phase change materials (PCM). We examine phase equilibrium changes, SLE and LLE with hydrocarbons and alcohols. [HQuin][NTf{sub 2}] may be proposed as entrainer for the separation proceses. - Abstract: The new quinolinium ionic liquid has been synthesised as a continuation of our work with quinolinium-based ionic liquids (ILs). The work includes specific basic characterisation of synthesized compounds: N-hexylquinolinium bromide, [HQuin][Br] and N-hexylquinolinium bis{l_brace}(trifluoromethyl)sulfonyl{r_brace}imide [HQuin][NTf{sub 2}] by NMR spectra, elementary analysis and water content. The basic thermal properties of the pure [HQuin][NTf{sub 2}] i.e. melting and glass-transition temperatures, the enthalpy of fusion as well as heat capacity have been measured using a differential scanning microcalorimetry technique (DSC) and thermal analysis instrument (TA). Densities and viscosities were determined as a function of temperature. Phase equilibria for the binary systems: {l_brace}[HQuin][NTf{sub 2}]) + aromatic hydrocarbon (benzene, or toluene, or ethylbenzene, or n-propylbenzene), or an alcohol (1-butanol, or 1-hexanol, or 1-octanol, or 1-decanol){r_brace} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (270 to 320) K. For all the binary systems with benzene and alkylbenzenes, the eutectic diagrams were observed with immiscibility gap in the liquid phase beginning from (0.13 to 0.28) mole fraction of the IL with very high an upper critical solution temperature (UCST). For mixtures with alcohols, the complete miscibility was observed for 1-butanol and immiscibility with UCST in the liquid phase for the remaining alcohols. The typical

Chemical Composition, Antimicrobial and Antioxidant Activities of the Flower Volatile Oils of Fagopyrum esculentum, Fagopyrum tataricum and Fagopyrum Cymosum

Directory of Open Access Journals (Sweden)

Jianglin Zhao

2018-01-01

Full Text Available The purpose of this study was to investigate the chemical composition and biological activity of the volatile oils (VOs from the flowers of three buckwheat species, Fagopyrum esculentum, Fagopyrum tataricum and Fagopyrum cymosum. The VOs were obtained from the fresh buckwheat flowers by hydrodistillation, and were analyzed for their chemical composition by gas chromatography-mass spectrometry (GC-MS. Nonanoic acid (7.58%, (E-3-hexen-1-ol (6.52%, and benzothiazole (5.08% were the major constituents among the 28 identified components which accounted for 92.89% of the total oil of F. esculentum. 2-Pentadecanone (18.61%, eugenol (17.18%, 1,2-benzenedicarboxylic acid, bis(2-methylpropyl ester (13.19%, and (E,E-farnesylacetone (7.15% were the major compounds among the 14 identified components which accounted for 88.48% of the total oil of F. tataricum. Eugenol (12.22%, (E-3-hexen-1-yl acetate (8.03%, linalool oxide (7.47%, 1-hexanol (7.07%, and benzothiazole (6.72% were the main compounds of the 20 identified components which accounted for 90.23% of the total oil of F. cymosum. The three VOs were screened to have broad spectrum antibacterial activity with minimum inhibitory concentration (MIC values ranged from 100.0 μg/mL to 800.0 μg/mL against the tested bacteria, and their median inhibitory concentration (IC50 values were from 68.32 μg/mL to 452.32 μg/mL. Xanthomonas vesicatoria was the most sensitive bacterium. Moreover, the flower VOs of F. esculentum, F. tataricum and F. cymosum also exhibited noteworthy antioxidant capacity with the IC50 value of 354.15 μg/mL, 210.63 μg/mL, and 264.92 μg/mL for the 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging assay, and the value of 242.06 μg/mL, 184.13 μg/mL, and 206.11 μg/mL respectively for the β-carotene-linoleic bleaching test. These results suggested the volatile oils of buckwheat flowers could be potential resource of natural antimicrobial and antioxidant agents.

Low fermentation pH is a trigger to alcohol production, but a killer to chain elongation

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Ramon eGanigué

2016-05-01

Full Text Available Gasification of organic wastes coupled to syngas fermentation allows the recovery of carbon in the form of commodity chemicals, such as carboxylates and biofuels. Acetogenic bacteria ferment syngas to mainly two-carbon compounds, although a few strains can also synthesize four-, and six-carbon molecules. In general, longer carbon chain products have a higher biotechnological (and commercial value due to their higher energy content and their lower water solubility. However, de-novo synthesis of medium-chain products from syngas is quite uncommon in bacteria. An alternative to de-novo synthesis is bioproduction of short-chain products (C2 and C4, and their subsequent elongation to C4, C6 or C8 through reversed β-oxidation metabolism. This two-step synergistic approach has been successfully applied for the production of up to C8 compounds, although, the accumulation of alcohols in these mixed cultures remained below detection limits. The present work investigates the production of higher alcohols from syngas by open mixed cultures (OMC. A syngas-fermenting community was enriched from sludge of an anaerobic digester for a period of 110 days in a lab-scale reactor. At the end of this period, stable production of ethanol and butanol was obtained. C6 compounds were only transiently produced at the beginning of the enrichment phase, during which Clostridium kluyveri, a bacterium able to carry out carbon chain elongation, was detected in the community. Further experiments showed pH as a critical parameter to maintain chain elongation activity in the co-culture. Production of C6 compounds was recovered by preventing fermentation pH to decrease below pH 4.5-5. Finally, experiments showed maximal production of C6 compounds (0.8 g/L and alcohols (1.7 g/L of ethanol, 1.1 g/L of butanol and 0.6 g/L of hexanol at pH 4.8. In conclusion, low fermentation pH is critical for the production of alcohols, although detrimental to C. kluyveri. Fine control of

Tailoring the key fuel properties using different alcohols (C2–C6) and their evaluation in gasoline engine

International Nuclear Information System (INIS)

Masum, B.M.; Masjuki, H.H.; Kalam, M.A.; Palash, S.M.; Wakil, M.A.; Imtenan, S.

2014-01-01

Highlights: • Optimized C 2 –C 6 alcohols–gasoline blends achieved better properties than E15. • Optimum blends improved torque and reduced BSFC than that of E15 fuel. • Higher peak in-cylinder pressure obtained for alcohol gasoline blends. • Compared to E15, optimum blends reduced BSCO, BSHC and BSNOx emission. - Abstract: The use of ethanol as a fuel for internal combustion engines has been given much attention mostly because of its possible environmental and long-term economical advantages over fossil fuel. Higher carbon number alcohols, such as propanol, butanol, pentanol and hexanol also have the potential to use as alternatives as they have higher energy content, octane number and can displace more petroleum gasoline than that of ethanol. Therefore, this study focuses on improvement of different physicochemical properties using multiple alcohols at different ratios compared to that of the ethanol–gasoline blend (E10/E15). To optimize the properties of multiple alcohol–gasoline blends, properties of each fuel were measured. An optimization tool of Microsoft Excel “Solver” was used to find out the optimum blend. Three optimum blends with maximum heating value (MaxH), maximum research octane number (MaxR) and maximum petroleum displacement (MaxD) are selected for testing in a four cylinder gasoline engine. Tests were conducted under the wide open throttle condition with varying speeds and compared results with that of E15 (Ethanol 15% with gasoline 85%) as well as gasoline. Optimized blends have shown higher brake torque than gasoline. In the terms of BSFC (Brake specific fuel consumption), optimized blends performed better than that of E15. In-cylinder pressure started to rise earlier for all alcohol–gasoline blends than gasoline. The peak in-cylinder pressure and peak heat release rate obtained higher for alcohol gasoline blend than that of gasoline. On the other hand, the use of optimized blends reduces BSCO (Brake specific carbon

Alcohol combustion chemistry

KAUST Repository

Sarathy, Mani

2014-10-01

Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

Metal ion extractant in microemulsions: where solvent extraction and surfactant science meet

International Nuclear Information System (INIS)

Bauer, C.

2011-01-01

-surfactants. The compositions of the C8G1/TBP and C8G1/n-hexanol interfacial mixed films obtained experimentally were confirmed by the prediction of a model based on the molecular geometrical parameters. We furthermore exploit the interfacial properties of these molecules to control the kinetics of liquid-liquid extraction and attempt a 'solvent free' ion separation using flotation. (author) [fr

In vivo functional expression of a screened P. aeruginosa chaperone-dependent lipase in E. coli

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Wu Xiangping

2012-09-01

Full Text Available Abstract Background Microbial lipases particularly Pseudomonas lipases are widely used for biotechnological applications. It is a meaningful work to design experiments to obtain high-level active lipase. There is a limiting factor for functional overexpression of the Pseudomonas lipase that a chaperone is necessary for effective folding. As previously reported, several methods had been used to resolve the problem. In this work, the lipase (LipA and its chaperone (LipB from a screened strain named AB which belongs to Pseudomonas aeruginosa were overexpressed in E. coli with two dual expression plasmid systems to enhance the production of the active lipase LipA without in vitro refolding process. Results In this work, we screened a lipase-produced strain named AB through the screening procedure, which was identified as P. aeruginosa on the basis of 16S rDNA. Genomic DNA obtained from the strain was used to isolate the gene lipA (936 bp and lipase specific foldase gene lipB (1023 bp. One single expression plasmid system E. coli BL21/pET28a-lipAB and two dual expression plasmid systems E. coli BL21/pETDuet-lipA-lipB and E. coli BL21/pACYCDuet-lipA-lipB were successfully constructed. The lipase activities of the three expression systems were compared to choose the optimal expression method. Under the same cultured condition, the activities of the lipases expressed by E. coli BL21/pET28a-lipAB and E. coli BL21/pETDuet-lipA-lipB were 1300 U/L and 3200 U/L, respectively, while the activity of the lipase expressed by E. coli BL21/pACYCDuet-lipA-lipB was up to 8500 U/L. The lipase LipA had an optimal temperature of 30°C and an optimal pH of 9 with a strong pH tolerance. The active LipA could catalyze the reaction between fatty alcohols and fatty acids to generate fatty acid alkyl esters, which meant that LipA was able to catalyze esterification reaction. The most suitable fatty acid and alcohol substrates for esterification were octylic acid and hexanol

Low temperature absorption chiller - Report from a project in the programs Climate 21 and 'More efficient refrigeration and heat pump systems. Final report; Laagtemperaturdriven absorptionskylmaskin - Rapport oever ett projekt inom programmen Klimat 21 och Effektivare Kyl- och Vaermepumpssystem. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Fredrik Setterwall [Fredrik Setterwall Konsult AB, Sollentuna (Sweden); Andersson, Mikael [AB Berglunds Rostfria, Boden (Sweden); Glebov, Dmitrey; Martin, Viktoria [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Technology

2005-06-01

An absorption chiller with a 1.15 MW cooling effect has been designed in a collaboration project comprising university, industry and end-user. This chiller is designed to run on district heating (70-90 deg C), and its layout and function differs from conventional absorption chillers as outlined below. The chiller's heat transfer surfaces may be installed horizontally or vertically, resulting in flexibility in system design. In a conventional absorption chiller, these surfaces are always horizontally aligned. The high-pressure and low-pressure parts of the chiller may be placed independently of each other. In a conventional chiller, the high-pressure part must always be placed on top of the low-pressure part. To enable the flexibility in design and system layout, this chiller is equipped with four internal pumps instead of only two in conventional design. The increased number of pumps leads to an increase of the installed electrical power for internal pumps. The electrical power for the internal pumps is however only a small fraction of the totally installed electrical power. The main part is utilized for pumping of cooling water and coolant. This low temperature driven, single-effect chiller has a high coefficient of performance (COP). The 'first generation machine' installed at Chalmers University of Technology has a COP equal to 0.75 at full load. Through the control strategy used, the chiller can maintain a high COP even at part load. Because of the high COP, the electricity consumption of the cooling water pump is kept low. To lower the size of the absorber and generator, the chiller is equipped with extra plate heat exchangers to cool the strong solution before the absorber, and preheat the weak solution before the generator. To increase the heat transfer rate, a new additive (2-methyl-penthanol) has been tested. As compared to the conventional heat transfer additive (2-ethyl-hexanol), the heat transfer enhancement was 20% higher with the new

Extraction and Identification of Secondary Metabolites Produced by Trichoderma atroviridae (6022 and Evaluating of their Antifungal Effects

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M. Shahiri Tabarestani

2017-08-01

. According to mass spectra library, 61 compounds such as some alkanes, alkenes, phenolic, alcoholic, terpenoid and aromatic compounds have been detected by 4 processes that among them, alkanes had the highest frequency. Many important compounds with the antifungal effect such as iso-amyl-alcohol, 2-ethyl-1-hexanol, 1-pentanol, stearic acid, palmitic acid, bis (2-ethylhexyl phthalate, di-n-octyl phthalate have been identified. So, inhibitory effects of isolate 6022 are related to these compounds. Conclusions: Secondary metabolites of the biocontrol fungus Trichoderma have been involved in different biological processes such as biocontrol or communication between fungi and their living environment. These fungi have antibiotic activity against plant pathogenic fungi, so the requirement for monitoring Trichoderma VOCs profiles has been offered. The results showed that isolate 6022 has the potential for controlling above mentioned pathogens so it can be the suitable alternative for chemical toxins. This method is simple for extraction of the secondary metabolites, under laboratory conditions and studied in Iran for the first time.