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Sample records for acetaldehyde acetone methanol

  1. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic marine air

    NASA Astrophysics Data System (ADS)

    Lewis, A. C.; Hopkins, J. R.; Carpenter, L. J.; Stanton, J.; Read, K. A.; Pilling, M. J.

    2005-08-01

    Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and acetaldehyde) contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene). The observations showed anomalies in the variance and abundance of acetaldehyde and acetone over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass motion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  2. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic air

    NASA Astrophysics Data System (ADS)

    Lewis, A. C.; Hopkins, J. R.; Carpenter, L. J.; Stanton, J.; Read, K. A.; Pilling, M. J.

    2005-03-01

    Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and 5 acetaldehyde) contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene). The observations showed anomalies in the variance and abundance of acetaldehyde and acetone 10 over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass mo15 tion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  3. Multiannual observations of acetone, methanol, and acetaldehyde in remote tropical atlantic air: implications for atmospheric OVOC budgets and oxidative capacity.

    PubMed

    Read, K A; Carpenter, L J; Arnold, S R; Beale, R; Nightingale, P D; Hopkins, J R; Lewis, A C; Lee, J D; Mendes, L; Pickering, S J

    2012-10-16

    Oxygenated volatile organic compounds (OVOCs) in the atmosphere are precursors to peroxy acetyl nitrate (PAN), affect the tropospheric ozone budget, and in the remote marine environment represent a significant sink of the hydroxyl radical (OH). The sparse observational database for these compounds, particularly in the tropics, contributes to a high uncertainty in their emissions and atmospheric significance. Here, we show measurements of acetone, methanol, and acetaldehyde in the tropical remote marine boundary layer made between October 2006 and September 2011 at the Cape Verde Atmospheric Observatory (CVAO) (16.85° N, 24.87° W). Mean mixing ratios of acetone, methanol, and acetaldehyde were 546 ± 295 pptv, 742 ± 419 pptv, and 428 ± 190 pptv, respectively, averaged from approximately hourly values over this five-year period. The CAM-Chem global chemical transport model reproduced annual average acetone concentrations well (21% overestimation) but underestimated levels by a factor of 2 in autumn and overestimated concentrations in winter. Annual average concentrations of acetaldehyde were underestimated by a factor of 10, rising to a factor of 40 in summer, and methanol was underestimated on average by a factor of 2, peaking to over a factor of 4 in spring. The model predicted summer minima in acetaldehyde and acetone, which were not apparent in the observations. CAM-Chem was adapted to include a two-way sea-air flux parametrization based on seawater measurements made in the Atlantic Ocean, and the resultant fluxes suggest that the tropical Atlantic region is a net sink for acetone but a net source for methanol and acetaldehyde. Inclusion of the ocean fluxes resulted in good model simulations of monthly averaged methanol levels although still with a 3-fold underestimation in acetaldehyde. Wintertime acetone levels were better simulated, but the observed autumn levels were more severely underestimated than in the standard model. We suggest that the latter may

  4. Proton transfer reactions between nitric acid and acetone, hydroxyacetone, acetaldehyde and benzaldehyde in the solid phase.

    PubMed

    Lasne, Jérôme; Laffon, Carine; Parent, Philippe

    2012-12-01

    The heterogeneous and homogeneous reactions of acetone, hydroxyacetone, acetaldehyde and benzaldehyde with solid nitric acid (HNO(3)) films have been studied with Reflection-Absorption Infrared Spectroscopy (RAIRS) under Ultra-High Vacuum (UHV) conditions in the 90-170 K temperature range. In the bulk or at the surface of the films, nitric acid transfers its proton to the carbonyl function of the organic molecules, producing protonated acetone-H(+), hydroxyacetone-H(+), acetaldehyde-H(+) and benzaldehyde-H(+), and nitrate anions NO(3)(-), a reaction not observed when nitric acid is previously hydrated [J. Lasne, C. Laffon and Ph. Parent, Phys. Chem. Chem. Phys., 2012, 14, 697]. This provides a molecular-scale description of the carbonyl protonation reaction in an acid medium, the first step of the acid-catalyzed condensation of carbonyl compounds, fuelling the growth of secondary organic aerosols (SOA) in the atmosphere.

  5. Sensitive gas chromatographic detection of acetaldehyde and acetone using a reduction gas detector

    NASA Technical Reports Server (NTRS)

    O'Hara, Dean; Singh, Hanwant B.

    1988-01-01

    The response of a newly available mercuric oxide Reduction Gas Detector (RGD-2) to subpicomole and larger quantities of acetaldehyde and acetone is tested. The RGD-2 is found to be capable of subpicomole detection for these carbonyls and is more sensitive than an FID (Flame Ionization Detector) by an order of magnitude. Operating parameters can be further optimized to make the RGD-2 some 20-40 times more sensitive than an FID. The detector is linear over a wide range and is easily adapted to a conventional gas chromatograph (GC). Such a GC-RGD-2 system should be suitable for atmospheric carbonyl measurements in clean as well as polluted environments.

  6. Acetaldehyde

    Integrated Risk Information System (IRIS)

    Acetaldehyde ; CASRN 75 - 07 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  7. Densities and refractive indices of acetone + methanol + 2-methyl-2-butanol at 298.15 K

    SciTech Connect

    Orge, B.; Iglesias, M.; Tojo, J.; Legido, J.L.

    1995-11-01

    Densities and refractive indices at 298.15 K for acetone + methanol + 2-methyl-2-butanol and the binary acetone + 2-methyl-2-butanol and methanol + 2-methyl-2-butanol mixtures have been measured as a function of the mole fraction at atmospheric pressure. Results have been correlated with analytical expressions.

  8. Molecular modeling of phase behavior and microstructure of acetone-chloroform-methanol binary mixtures.

    PubMed

    Kamath, Ganesh; Georgiev, Grigor; Potoff, Jeffrey J

    2005-10-20

    Force fields based on a Lennard-Jones (LJ) 12-6 plus point charge functional form are developed for acetone and chloroform specifically to reproduce the minimum pressure azeotropy found experimentally in this system. Point charges are determined from a CHELPG population analysis performed on an acetone-chloroform dimer. The required electrostatic surface for this dimer is determined from ab initio calculations performed with MP2 theory and the 6-31g++(3df,3pd) basis set. LJ parameters are then optimized such that the liquid-vapor coexistence curve, critical parameters, and vapor pressures are well reproduced by simulation. Histogram-reweighting Monte Carlo simulations in the grand canonical ensemble are used to determine the phase diagrams for the binary mixtures acetone-chloroform, acetone-methanol, and chloroform-methanol. The force fields developed in this work reproduce the minimum pressure azeotrope in the acetone-chloroform mixture found in experiment. The predicted azeotropic composition of x(CHCl3) = 0.77 is in fair agreement with the experimental value of x(CHCl3)expt = 0.64. The new force fields were also found to provide improved predictions of the pressure-composition behavior of acetone-methanol and chloroform-methanol when compared to other force fields commonly used for vapor-liquid equilibria calculations. NPT simulations were conducted at 300 K and 1 bar for equimolar mixtures of acetone-chloroform, acetone-methanol, and methanol-chloroform. Analysis of the microstructure reveals significant hydrogen bonding occurring between acetone and chloroform. Limited interspecies hydrogen bonding was found in the acetone-methanol or chloroform-methanol mixtures.

  9. Densities and refractive indices for acetone + methanol + 1-propanol at 298.15 K

    SciTech Connect

    Iglesias, M.; Orge, B.; Tojo, J.

    1996-03-01

    Densities and refractive indices at 298.15 K for acetone + methanol + 1-propanol and the binary acetone + 1-propanol and methanol + 1-propanol mixtures have been measured as a function of the mole fraction at atmospheric pressure. Parameters of analytical expressions which represent the composition dependences of physical properties and excess values are reported. The refractive index results are compared with estimation methods. The excess properties for the ternary mixture are compared with those estimated on the basis of binary property contributions.

  10. Uptake and Reactions of Formaldehyde, Acetaldehyde, Acetone, Propanal and Ethanol in Sulfuric Acid solutions at 200-240 K: Implications for upper tropospheric aerosol composition

    NASA Astrophysics Data System (ADS)

    Iraci, L. T.; Williams, M. B.; Axson, J.; Michelsen, R.

    2007-12-01

    The production of light absorbing, organic material in aerosol that is normally considered to be transparent in the UV and visible wavelength regions has significant implications for biogeochemical cycling and climate modelling. Production mechanisms likely involve carbonyl compounds such as formaldehyde, acetone, acetaldehyde and propanal that are present in significant quantities in the upper troposphere (UT). In this study, we have performed experiments focusing on a class of acid catalyzed carbonyl reactions, the formation of acetals. R2C=O + 2R'OH --> R2C(OR')2 + H2O Using a Knudsen cell apparatus, we have measured the rate of uptake of formaldehyde, acetaldehyde, acetone, propanal, and ethanol into sulfuric acid solutions ranging between 40-70 wt% of acid, containing 0-0.1 M of ethanol, acetone or formaldehyde at temperatures of 220-250 K. For all reactant pairs, the aldol condensation path, including self reaction, should be insignificant at the acidities studied. Evidence for reaction between organics was observed for all pairs, except those involving propanal which were likely limited by the very low solubility. We attribute enhanced uptake to the formation of acetals, such as 1,1-diethoxyethane and 2,2- diethoxypropane, among others. Enhanced uptake was observed to proceed on timescales > 1 hour and sometimes shows complex dependence on acidity that is likely related to speciation of the individual carbonyls in acidic solution. The acetal products do not absorb in the visible but are less volatile than parent molecules, allowing for accumulation in sulfuric acid particles, and enhanced uptake. Cross reactions of carbonyls with alcohols in sulfuric acid medium have not been previously measured, yet methanol and ethanol show high solubility and are present at significant concentrations in the UT. Thus even at slow reaction rates, the acetal reaction has ample starting material and proceeds under conditions common to the UT. We will present results for the

  11. Site Competition During Coadsorption of Acetone with Methanol and Water on TiO2(110)

    SciTech Connect

    Shen, Mingmin; Henderson, Michael A.

    2011-08-02

    The competitive interaction between acetone and two solvent molecules (methanol and water) for surface sites on rutile TiO2(110) was studied using temperature programmed desorption (TPD). On a vacuum reduced TiO2(110) surface, which possessed ~5% oxygen vacancy sites, excess methanol displaced preadsorbed acetone molecules to weakly bound and physisorbed desorption states below 200 K, whereas acetone was stabilized to 250 K against displacement by methanol on an oxidized surface through formation of an acetone-diolate species. These behaviors of acetone differ from the competitive interactions between acetone and water in that acetone is less susceptible to displacement by water. Examination of acetone+methanol and acetone+water multilayer combinations shows that acetone is more compatible in water-ice films than in methanol-ice films, presumably because water has greater potential as a hydrogen-bond donor than does methanol. Acetone molecules displaced from the TiO2(110) surface by water are more likely to be retained in the near-surface region, having a greater opportunity to revisit the surface, than when methanol is used as a coadsorbate. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  12. Fate of partially oxidised hydrocarbons in the UT: Reaction of OH with acetaldehyde, formaldehyde and methanol.

    NASA Astrophysics Data System (ADS)

    Sivakumaran, V.; Cameron, M.; Dillon, T. J.; Hoelscher, D.; Horowitz, A.; Crowley, J. N.

    2003-04-01

    Partially Oxidised Hydrocarbons (POH) strongly influence the formation of HOx and ozone in the upper troposphere [1]. POH are formed in the atmosphere as intermediates in the oxidation of methane non-methane hydrocarbons and are also directly emitted in the boundary layer as a result of biogenic processes and from combustion systems. Although the OH initiated oxidation is an important sink of many POH, the available kinetic data for the reaction of OH with formaldehyde, acetaldehyde and methanol relevant to upper tropospheric temperatures (210-240 K) is limited, and the measured rate constants have a large uncertainties [2]. Also there is a lack of definitive product and mechanistic data for these reactions. We present new, highly accurate rate constants for reaction of OH with formaldehyde, acetaldehyde and methanol at temperatures down to 201 K. We also present direct measurements of branching ratios to the various thermodynamically accessible product channels of these reactions. 1. Singh, H., et al., Evidence from the Pacific troposphere for large global sources of oxygenated organic compounds. Nature, 410, 2001, 1078-1081. 2. Atkinson, R., et al., Evaluated kinetic and photochemical data for atmospheric chemistry, organic species: Supplement VII. IUPAC subcommittee on gas kinetic data evaluation for atmospheric chemistry. J. Phys. Chem. Ref. Data, 28, 1999. 191-393.

  13. Microscopic roots of alcohol-ketone demixing: infrared spectroscopy of methanol-acetone clusters.

    PubMed

    Kollipost, Franz; Domanskaya, Alexandra V; Suhm, Martin A

    2015-03-19

    Infrared spectra of isolated methanol-acetone clusters up to tetramers are experimentally characterized for the first time. They show evidence for a nanometer-scale demixing trend of the cold species. In combination with quantum calculations, the mutual repulsion is demonstrated to start beyond three molecular units, whereas individual molecules still prefer to form a mixed complex.

  14. Free energy of mixing of acetone and methanol: a computer simulation investigation.

    PubMed

    Idrissi, Abdenacer; Polok, Kamil; Barj, Mohammed; Marekha, Bogdan; Kiselev, Mikhail; Jedlovszky, Pál

    2013-12-19

    The change of the Helmholtz free energy, internal energy, and entropy accompanying the mixing of acetone and methanol is calculated in the entire composition range by the method of thermodynamic integration using three different potential model combinations of the two compounds. In the first system, both molecules are described by the OPLS, and in the second system, both molecules are described by the original TraPPE force field, whereas in the third system a modified version of the TraPPE potential is used for acetone in combination with the original TraPPE model of methanol. The results reveal that, in contrast with the acetone-water system, all of these three model combinations are able to reproduce the full miscibility of acetone and methanol, although the thermodynamic driving force of this mixing is very small. It is also seen, in accordance with the finding of former structural analyses, that the mixing of the two components is driven by the entropy term corresponding to the ideal mixing, which is large enough to overcompensate the effect of the energy increase and entropy loss due to the interaction of the unlike components in the mixtures. Among the three model combinations, the use of the original TraPPE model of methanol and modified TraPPE model of acetone turns out to be clearly the best in this respect, as it is able to reproduce the experimental free energy, internal energy, and entropy of mixing values within 0.15 kJ/mol, 0.2 kJ/mol, and 1 J/(mol K), respectively, in the entire composition range. The success of this model combination originates from the fact that the use of the modified TraPPE model of acetone instead of the original one in these mixtures improves the reproduction of the entropy of mixing, while it retains the ability of the original model of excellently reproducing the internal energy of mixing.

  15. Acetone

    Integrated Risk Information System (IRIS)

    Acetone ; CASRN 67 - 64 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  16. Quality Characteristics and Quantification of Acetaldehyde and Methanol in Apple Wine Fermentation by Various Pre-Treatments of Mash

    PubMed Central

    Won, Seon Yi; Seo, Jae Soon; Kwak, Han Sub; Lee, Youngseung; Kim, Misook; Shim, Hyoung-Seok; Jeong, Yoonhwa

    2015-01-01

    The objective of this study was to compare the effects of adding lactic acid and pectinase, and chaptalization for the quality of apple wine and the production of hazardous compounds (methanol and acetaldehyde). The pH of all of the samples was below 4; therefore, mash seemed to be fermented without any issue. Total acidity was the highest in sample A due to lactic acid addition. Pre-treated groups (samples B, C, and D) showed higher total acidities than that of the control (P<0.05). Pre-treatments might influence the production of organic acids in apple wines. The control and pectinase added sample (sample B) had the lowest alcohol contents. Adding lactic acid produced more alcohol, and chaptalized samples produced more alcohol due to the addition of sugar. Adding pectinase with and without chaptalization was not effective for producing more alcohol. The control sample had significantly higher acetaldehyde content (2.39 mg/L) than the other samples (1.00~2.07 mg/L); therefore, pre-treatments for apple wine fermentation produced a lower amount of acetaldehyde. Among the pre-treated samples, samples C and D showed the lowest acetaldehyde content of 1.00 mg/L and 1.16 mg/L, respectively. On the other hand, a significantly higher amount of methanol was generated for sample A (1.03 mg/L) and sample D (1.22 mg/L) than that of the control (0.82 mg/L) (P<0.05). Adding lactic acid or chaptalization was effective in reducing methanol and acetaldehyde in apple wines. PMID:26770917

  17. Quality Characteristics and Quantification of Acetaldehyde and Methanol in Apple Wine Fermentation by Various Pre-Treatments of Mash.

    PubMed

    Won, Seon Yi; Seo, Jae Soon; Kwak, Han Sub; Lee, Youngseung; Kim, Misook; Shim, Hyoung-Seok; Jeong, Yoonhwa

    2015-12-01

    The objective of this study was to compare the effects of adding lactic acid and pectinase, and chaptalization for the quality of apple wine and the production of hazardous compounds (methanol and acetaldehyde). The pH of all of the samples was below 4; therefore, mash seemed to be fermented without any issue. Total acidity was the highest in sample A due to lactic acid addition. Pre-treated groups (samples B, C, and D) showed higher total acidities than that of the control (P<0.05). Pre-treatments might influence the production of organic acids in apple wines. The control and pectinase added sample (sample B) had the lowest alcohol contents. Adding lactic acid produced more alcohol, and chaptalized samples produced more alcohol due to the addition of sugar. Adding pectinase with and without chaptalization was not effective for producing more alcohol. The control sample had significantly higher acetaldehyde content (2.39 mg/L) than the other samples (1.00~2.07 mg/L); therefore, pre-treatments for apple wine fermentation produced a lower amount of acetaldehyde. Among the pre-treated samples, samples C and D showed the lowest acetaldehyde content of 1.00 mg/L and 1.16 mg/L, respectively. On the other hand, a significantly higher amount of methanol was generated for sample A (1.03 mg/L) and sample D (1.22 mg/L) than that of the control (0.82 mg/L) (P<0.05). Adding lactic acid or chaptalization was effective in reducing methanol and acetaldehyde in apple wines. PMID:26770917

  18. A theoretical investigation of the plausibility of reactions between ammonia and carbonyl species (formaldehyde, acetaldehyde, and acetone) in interstellar ice analogs at ultracold temperatures.

    PubMed

    Chen, Lina; Woon, David E

    2011-05-26

    We have reexamined the reaction between formaldehyde and ammonia, which was previously studied by us and other workers in modestly sized cluster calculations. Larger model systems with up to 12H(2)O were employed, and reactions of two more carbonyl species, acetaldehyde and acetone, were also carried out. Calculations were performed at the B3LYP/6-31+G** level with bulk solvent effects treated with a polarizable continuum model; limited MP2/6-31+G** calculations were also performed. We found that while the barrier for the concerted proton relay mechanism described in previous work remains modest, it is still prohibitively high for the reaction to occur under the ultracold conditions that prevail in dense interstellar clouds. However, a new pathway emerged in more realistic clusters that involves at least one barrierless step for two of the carbonyl species considered here: ammonia reacts with formaldehyde and acetaldehyde to form a partial charge transfer species in small clusters (4H(2)O) and a protonated hydroxyamino intermediate species in large clusters (9H(2)O, 12H(2)O); modest barriers that decrease sharply with cluster size are found for the analogous processes for the acetone-NH(3) reaction. Furthermore, if a second ammonia replaces one of the water molecules in calculations in the 9H(2)O clusters, deprotonation can occur to yield the same neutral hydroxyamino species that is formed via the original concerted proton relay mechanism. In at least one position, deprotonation is barrierless when zero-point energy is included. In addition to describing the structures and energetics of the reactions between formaldehyde, acetaldehyde, and acetone with ammonia, we report spectroscopic predictions of the observable vibrational features that are expected to be present in ice mixtures of different composition.

  19. A Theoretical Investigation of the Plausibility of Reactions Between Ammonia and Carbonyl Species (Formaldehyde, Acetaldehyde, and Acetone) in Interstellar Ice Analogs at Ultracold Temperatures

    NASA Technical Reports Server (NTRS)

    Chen, Lina; Woon, David E.

    2011-01-01

    We have reexamined the reaction between formaldehyde and ammonia, which was previously studied by us and other workers in modestly sized cluster calculations. Larger model systems with up to 12H2O were employed, and reactions of two more carbonyl species, acetaldehyde and acetone, were also carried out. Calculations were performed at the B3LYP/6-31+G** level with bulk solvent effects treated with a polarizable continuum model; limited MP2/6-31+G** calculations were also performed. We found that while the barrier for the concerted proton relay mechanism described in previous work remains modest, it is still prohibitively high for the reaction to occur under the ultracold conditions that prevail in dense interstellar clouds. However, a new pathway emerged in more realistic clusters that involves at least one barrierless step for two of the carbonyl species considered here: ammonia reacts with formaldehyde and acetaldehyde to form a partial charge transfer species in small clusters (4H2O) and a protonated hydroxyamino intermediate species in large clusters (9H2O, 12H2O); modest barriers that decrease sharply with cluster size are found for the analogous processes for the acetone-NH3 reaction. Furthermore, if a second ammonia replaces one of the water molecules in calculations in the 9H2O clusters, deprotonation can occur to yield the same neutral hydroxyamino species that is formed via the original concerted proton relay mechanism. In at least one position, deprotonation is barrierless when zero-point energy is included. In addition to describing the structures and energetics of the reactions between formaldehyde, acetaldehyde, and acetone with ammonia, we report spectroscopic predictions of the observable vibrational features that are expected to be present in ice mixtures of different composition.

  20. Interaction of acetone, hydroxyacetone, acetaldehyde and benzaldehyde with the surface of water ice and HNO3·3H2O ice.

    PubMed

    Lasne, Jérôme; Laffon, Carine; Parent, Philippe

    2012-01-14

    Oxygenated volatile organic compounds (OVOCs) influence the oxidative properties of the atmosphere, and their transport from the ground may occur by scavenging by the HNO(3)-rich supercooled water droplets found in polluted convective air masses. With infrared spectroscopy, we have studied the interactions of four typical atmospheric OVOCs (acetone, hydroxyacetone, acetaldehyde and benzaldehyde) with model surfaces of water ice and of trihydrated nitric acid (NAT) ice. We show that these molecules weakly adsorb on water ice and NAT by hydrogen bonding. No chemical reaction occurs between the molecules and the NAT substrate, the OVOCs remaining intact when in contact with hydrated HNO(3) in atmospheric ice clouds.

  1. Rate constants for hydrogen abstraction reactions by the hydroperoxyl radical from methanol, ethenol, acetaldehyde, toluene, and phenol.

    PubMed

    Altarawneh, Mohammednoor; Al-Muhtaseb, Ala'A H; Dlugogorski, Bogdan Z; Kennedy, Eric M; Mackie, John C

    2011-06-01

    An important step in the initial oxidation of hydrocarbons at low to intermediate temperatures is the abstraction of H by hydroperoxyl radical (HO(2)). In this study, we calculate energy profiles for the sequence: reactant + HO(2) → [complex of reactants] → transition state → [complex of products] → product + H(2)O(2) for methanol, ethenol (i.e., C(2)H(3)OH), acetaldehyde, toluene, and phenol. Rate constants are provided in the simple Arrhenius form. Reasonable agreement was obtained with the limited literature data available for acetaldehyde and toluene. Addition of HO(2) to the various distinct sites in phenol is investigated. Direct abstraction of the hydroxyl H was found to dominate over HO(2) addition to the ring. The results presented herein should be useful in modeling the lower temperature oxidation of the five compounds considered, especially at low temperature where the HO(2) is expected to exist at reactive levels. PMID:21370242

  2. Shear viscosity of polar liquid mixtures via non-equilibrium molecular dynamics: water, methanol, and acetone

    NASA Astrophysics Data System (ADS)

    Wheeler Richard, Dean R.; Rowley, L.

    Non-equilibrium molecular dynamics (NEMD) with isobaric and isokinetic controls were used to simulate the shear viscosity for binary mixtures of water, methanol and acetone, and for ternary mixtures. In all, 22 different liquid composition points were simulated at 298.15 K and 0.1 MPa. A new set of acetone potential parameters was developed, while slight variants to existing water and methanol models were used. Long range Coulombic interactions were computed with the Ewald sum adapted to Lees-Edwards boundary conditions as formulated in Wheeler, D. R., Fuller, N. G., and Rowley, R. L., 1997, Molec. Phys., 92, 55. The attractive (dispersive) part of the Lennard-Jones (LJ) interactions also was handled by a lattice sum. A hybrid mixing rule was used for the LJ cross interactions. Viscosities extrapolated to zero shear compared well with experimental results, having a mean absolute error of 14% and no errors greater than 30%. Although the simulations successfully predicted viscosity maxima for mixtures high in water content, the peak heights tended to be too low, probably due to the limitations of the water model. The results suggest that NEMD may be a viable means of estimating viscosities for polar liquid mixtures with an unrestricted number of components.

  3. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride.

    PubMed

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y Mauricio; Vrabec, Jadran

    2016-03-28

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values. PMID:27036455

  4. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y. Mauricio; Vrabec, Jadran

    2016-03-01

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values.

  5. Kinetics of the unimolecular reaction of CH2OO and the bimolecular reactions with the water monomer, acetaldehyde and acetone under atmospheric conditions.

    PubMed

    Berndt, Torsten; Kaethner, Ralf; Voigtländer, Jens; Stratmann, Frank; Pfeifle, Mark; Reichle, Patrick; Sipilä, Mikko; Kulmala, Markku; Olzmann, Matthias

    2015-08-14

    Stabilized Criegee Intermediates (sCIs) have been identified as oxidants of atmospheric trace gases such as SO2, NO2, carboxylic acids or carbonyls. The atmospheric sCI concentrations, and accordingly their importance for trace gas oxidation, are controlled by the rate of the most important loss processes, very likely the unimolecular reactions and the reaction with water vapour (monomer and dimer) ubiquitously present at high concentrations in the troposphere. In this study, the rate coefficients of the unimolecular reaction of the simplest sCI, formaldehyde oxide, CH2OO, and its bimolecular reaction with the water monomer have been experimentally determined at T = (297 ± 1) K and at atmospheric pressure by using a free-jet flow system. CH2OO was produced by the reaction of ozone with C2H4, and CH2OO concentrations were probed indirectly by detecting H2SO4 after titration with SO2. Time-resolved experiments yield a rate coefficient of the unimolecular reaction of k(uni) = (0.19 ± 0.07) s(-1), a value that is supported by quantum-chemical and statistical rate theory calculations as well as by additional measurements performed under CH2OO steady-state conditions. A rate coefficient of k(CH2OO+H2O) = (3.2 ± 1.2) × 10(-16) cm(3) molecule(-1) s(-1) has been determined for sufficiently low H2O concentrations (<10(15) molecule cm(-3)) that allow separation from the CH2OO reaction with the water dimer. In order to evaluate the accuracy of the experimental approach, the rate coefficients of the reactions with acetaldehyde and acetone were reinvestigated. The obtained rate coefficients k(CH2OO+acetald) = (1.7 ± 0.5) × 10(-12) and k(CH2OO+acetone) = (3.4 ± 0.9) × 10(-13) cm(3) molecule(-1) s(-1) are in good agreement with literature data.

  6. Effects of acetone, acetonitrile, ethanol, methanol and DMSO on cytochrome P450 in rainbow trout (Oncorhynchus mykiss) hepatic microsomes.

    PubMed

    Sakalli, Sidika; Burkina, Viktoriia; Zlabek, Vladimir; Zamaratskaia, Galia

    2015-01-01

    In vitro impacts of five organic solvents on cytochrome P450 (CYP450) enzyme activity were investigated using hepatic microsomes of rainbow trout. The rates of several CYP450-mediated reactions were investigated at solvent concentrations ranging from 0.01% to 3%. The solvents greatly affected all tested reactions. In at least 0.8% ethanol, 2% methanol or acetone, 1% acetonitrile or 3% dimethyl sulfoxide (DMSO), 7-ethoxyresorufin-O-deethylase (EROD) activity decreased and at 3% acetonitrile or ethanol, it was undetected. At 3%, all tested solvents except methanol reduced 7-benzyloxy-4-trifluoromethylcoumarin-O-debenzylase (BFCOD) activity, but at low concentrations of ethanol (2% and lower) or DMSO (1% and lower), it was induced. This was not seen with the inclusion of a pre-incubation step. p-Nitrophenolhydroxylase (PNPH) activity was not affected at concentrations below 1% DMSO, and at 2% acetonitrile it was reduced, as it was above 1% methanol or 0.5% ethanol. Acetone did not affect PNPH activity with or without a pre-incubation step. In general, the degree of inhibition was similar with and without the pre-incubation step. We conclude that the concentration of organic solvent for solubilizing the substrate and inhibitor in in vitro microsomal studies should be minimized.

  7. Acetonic and Methanolic Extracts of Heterotheca inuloides, and Quercetin, Decrease CCl4-Oxidative Stress in Several Rat Tissues

    PubMed Central

    Coballase-Urrutia, Elvia; Pedraza-Chaverri, José; Cárdenas-Rodríguez, Noemí; Huerta-Gertrudis, Bernardino; García-Cruz, Mercedes Edna; Montesinos-Correa, Hortencia; Sánchez-González, Dolores Javier; Camacho-Carranza, Rafael; Espinosa-Aguirre, Jesús Javier

    2013-01-01

    The present study was designed to test the hypothesis that the acetonic and methanolic extracts of H. inuloides prevent carbon tetrachloride-(CCl4) induced oxidative stress in vital tissues. Pretreatment with both H. inuloides extracts or quercetin attenuated the increase in serum activity of alkaline phosphatase (ALP), total bilirubin (BB), creatinine (CRE), and creatine kinase (CK), and impeded the decrease of γ-globulin (γ-GLOB) and albumin (ALB) observed in CCl4-induced tissue injury. The protective effect was confirmed by histological analysis with hematoxylin-eosin and periodic acid/Schiff's reagent. Level of lipid peroxidation was higher in the organs of rats exposed to CCl4 than in those of the animals treated with Heterohteca extracts or quercetin, and these showed levels similar to the untreated group. Pretreatment of animals with either of the extracts or quercetin also prevented the increase of 4-hydroxynonenal and 3-nitrotyrosine. Pretreatment with the plant extracts or quercetin attenuated CCl4 toxic effects on the activity of several antioxidant enzymes. The present results strongly suggest that the chemopreventive effect of the extracts used and quercetin, against CCl4 toxicity, is associated with their antioxidant properties and corroborated previous results obtained in liver tissue. PMID:23365610

  8. The enthalpies and entropies of pefloxacin dissolution in methanol, ethanol, 1-Propanol, 2-Propanol, acetone, and chloroform at 293.15-323.15 K

    NASA Astrophysics Data System (ADS)

    Zhang, C.-L.; Cui, S.-J.; Wang, Y.

    2012-12-01

    The solubilities of pefloxacin in methanol, ethanol, 1-propanol, 2-propanol, acetone, and chloroform have been determined from 293.15 to 323.15 K by a static equilibrium method. The experimental data were correlated with the modified Apelblat equation. The positive Δsol H and Δsol S for each system revealed that pefloxacin dissolution in each solvent is an entropy-driven process.

  9. Adsorptive Separation of Methanol-Acetone on Isostructural Series of Metal-Organic Frameworks M-BTC (M = Ti, Fe, Cu, Co, Ru, Mo): A Computational Study of Adsorption Mechanisms and Metal-Substitution Impacts.

    PubMed

    Wu, Ying; Chen, Huiyong; Xiao, Jing; Liu, Defei; Liu, Zewei; Qian, Yu; Xi, Hongxia

    2015-12-01

    The adsorptive separation properties of M-BTC isostructural series (M = Ti, Fe, Cu, Co, Ru, Mo) for methanol-acetone mixtures were investigated by using various computational procedures of grand canonical Monte Carlo simulations (GCMC), density functional theory (DFT), and ideal adsorbed solution theory (IAST), following with comprehensive understanding of adsorbate-metal interactions on the adsorptive separation behaviors. The obtained results showed that the single component adsorptions were driven by adsorbate-framework interactions at low pressures and by framework structures at high pressures, among which the mass effects, electrostatics, and geometric accessibility of the metal sites also played roles. In the case of methanol-acetone separation, the selectivity of methanol on M-BTCs decreased with rising pressures due to the pressure-dependent separation mechanisms: the cooperative effects between methanol and acetone hindered the separation at low pressures, whereas the competitive effects of acetone further resulted in the lower selectivity at high pressures. Among these M-BTCs, Ti and Fe analogues exhibited the highest thermodynamic methanol/acetone selectivity, making them promising for adsorptive methanol/acetone separation processes. The investigation provides mechanistic insights on how the nature of metal centers affects the adsorption properties of MOFs, and will further promote the rational design of new MOF materials for effective gas mixture separation. PMID:26581027

  10. Properties of the liquid-vapor interface of acetone-methanol mixtures, as seen from computer simulation and ITIM surface analysis.

    PubMed

    Idrissi, Abdenacer; Hantal, György; Jedlovszky, Pál

    2015-04-14

    Molecular dynamics simulations of the liquid-vapor interface of acetone-methanol mixtures of different compositions, including the two neat systems, have been performed on the canonical (N,V,T) ensemble at 293 K. The intrinsic liquid surface has been determined in terms of the Identification of the Truly Interfacial Molecules (ITIM) method. The results have revealed that the proximity of the interface influences the properties of only the first molecular layer of the liquid phase, while the second layer already turns out to be bulk-like in every respect. The two molecules are distributed uniformly along the macroscopic surface normal axis, as no strong preference for surface adsorption is shown by any of them. However, similarly to the bulk liquid phase, both molecules exhibit a marked tendency for self-association within the surface layer. Surface orientations are found to be composition independent; all the preferred orientations of both molecules correspond to the same alignment of the molecular dipole vector, which is nearly parallel to the macroscopic surface plane, declining only 10-20° from it towards the vapor phase. The surface properties are thus primarily governed by dipolar interactions, whereas hydrogen bonding within the surface layer, which decreases steadily with an increase in the acetone mole fraction, plays only a minor role in this respect.

  11. Three-dimensionally ordered and wormhole-like mesoporous iron oxide catalysts highly active for the oxidation of acetone and methanol.

    PubMed

    Xia, Yunsheng; Dai, Hongxing; Jiang, Haiyan; Zhang, Lei; Deng, Jiguang; Liu, Yuxi

    2011-02-15

    Three-dimensionally (3D) ordered and wormhole-like mesoporous iron oxides (denoted as Fe-KIT6 and Fe-CA) were respectively prepared by adopting the 3D ordered mesoporous silica KIT-6-templating and modified citric acid-complexing strategies, and characterized by a number of analytical techniques. It is shown that the Fe-KIT6-400 and Fe-CA-400 catalysts derived after 400°C-calcination possessed high surface areas (113-165 m(2)/g), high surface adsorbed oxygen concentrations, and good low-temperature reducibility, giving 90% conversion below 189 and 208°C for acetone and methanol oxidation at 20,000 mL/(g h), respectively. It is believed that the good catalytic performance of Fe-CA-400 and Fe-KIT6-400 was related to factors such as higher surface area and oxygen adspecies concentration, better low-temperature reducibility, and 3D mesoporous architecture.

  12. Comparison of the nutritional value and biological activities of the acetone, methanol and water extracts of the leaves of Solanum nigrum and Leonotis leonorus.

    PubMed

    Jimoh, F O; Adedapo, A A; Afolayan, A J

    2010-03-01

    The nutritional, phytochemical, antioxidant and antibacterial activities of the acetone, methanol and water extracts of the leaves of Solanum nigrum and Leonotis leonorus were investigated using standard analytical methods in order to assess the numerous potential of the leaves of these plants. The proximate analysis showed the that the leaves of the two plants were rich in moisture content, ash content, crude protein, crude lipid, crude fibre and carbohydrate. Elemental analysis in mg/100g (DW) indicated that the leaves contained sodium, potassium, calcium, magnesium, iron, zinc, phosphorus, copper, manganese, and nitrogen. The chemical composition in mg/100g (DW) for alkaloid, saponins, and phytate were moderate. The plants were also rich in polyphenols and had good antioxidant activities. The different extracts of the plants had activities against some of the organisms used in this study. Comparing the nutrient and chemical constituents with recommended dietary allowance (RDA) values, the results reveal that the leaves contain an appreciable amount of nutrients, minerals, and phytochemicals and low levels of toxicants. PMID:20079394

  13. Acetone poisoning

    MedlinePlus

    Dimethyl formaldehyde poisoning; Dimethyl ketone poisoning; Nail polish remover poisoning ... Acetone can be found in: Nail polish remover Some cleaning solutions Some glues, including rubber cement Some lacquers Other products may also contain acetone.

  14. Methanol

    Integrated Risk Information System (IRIS)

    Methanol ; CASRN 67 - 56 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  15. Acetone in theGlobal Troposphere: Its Possible Role as a Global Source of PAN

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; Kanakidou, M.

    1994-01-01

    Oxygenated hydrocarbons are thought to be important components of the atmosphere but, with the exception of formaldehyde, very little about their distribution and fate is known. Aircraft measurements of acetone (CH3COCH3), PAN (CH3CO3NO2) and other organic species (e. g. acetaldehyde, methanol and ethanol) have been performed over the Pacific, the southern Atlantic, and the subarctic atmospheres. Sampled areas extended from 0 to 12 km altitude over latitudes of 70 deg N to 40 deg S. All measurements are based on real time in-situ analysis of cryogenically preconcentrated air samples. Substantial concentrations of these oxygenated species (10-2000 ppt) have been observed at all altitudes and geographical locations in the troposphere. Important sources include, emissions from biomass burning, plant and vegetation, secondary oxidation of primary non-methane hydrocarbons, and man-made emissions. Direct measurements within smoke plumes have been used to estimate the biomass burning source. Photochemistry studies are used to suggest that acetone could provide a major source of peroxyacetyl radicals in the atmosphere and play an important role in sequestering reactive nitrogen. Model calculations show that acetone photolysis contributes significantly to PAN formation in the middle and upper troposphere.

  16. Alcoholic myopathy and acetaldehyde.

    PubMed

    Preedy, Victor R; Crabb, David W; Farrés, Jaume; Emery, Peter W

    2007-01-01

    Alcoholic myopathy is characterized by biochemical and morphological lesions within muscle, ranging from impairment of muscle strength and loss of lean tissue to cellular disturbances and altered gene expression. The chronic form of the disease is five times more common than cirrhosis and is characterized by selective atrophy of type 11 (anaerobic) fibres: type I (aerobic) fibres are relatively protected. Although the causative agent is known (i.e. ethanol), the intervening steps between alcohol ingestion and the development of symptoms and lesions are poorly understood. However, acetaldehyde appears to have an important role in the aetiology of the disease. For example, alcohol is a potent perturbant of muscle protein synthesis in vivo, and this effect is exacerbated by cyanamide pre-dosage, which raises acetaldehyde concentrations. Acetaldehyde alone also reduces muscle protein synthesis in vivo and proteolytic activity in vitro. The formation of acetaldehyde protein adducts is another mechanism of putative importance in alcoholic myopathy. These adducts are formed within muscle in response to either acute or chronic alcohol exposure and the adducts are located preferentially within the sarcolemmal and sub-sarcolemmal regions. However, the significance of protein adduct formation is unclear since we do not currently know the identity of the adducted muscle proteins nor whether adduction alters the biochemical or functional properties of skeletal muscle proteins.

  17. Purity Determination of Acetaldehyde in an Acetaldehyde Certified Reference Material.

    PubMed

    Yamazaki, Taichi; Watanabe, Takuro; Nakamura, Satoe; Kato, Kenji

    2015-01-01

    Acetaldehyde is regulated as a toxic substance in various fields, and the method for monitoring or analysis of acetaldehyde is important. However, handling is difficult because of the high reactivity and low boiling point of acetaldehyde. Therefore, a reference material for high purity acetaldehyde with high accuracy was not available. Although the measuring method of acetaldehyde as a reagent is published in the Japanese Industrial Standard (JIS) where the specification of acetaldehyde purity is more than 80%, the analytical method described in JIS is not enough for an accuracy purity determination method. In this research, the high precision purity determination method for development of a certified reference material (CRM) of acetaldehyde was examined. By controlling the volatility and reactivity of acetaldehyde, we established the purity determination method of acetaldehyde with a relative standard uncertainty of less than 0.3%. Furthermore, this method was applied to develop a high purity acetaldehyde CRM with an expanded uncertainty of 0.005 kg kg(-1) (k = 2). PMID:26063006

  18. Acetaldehyde: A Chemical Whose Fortunes Have Changed.

    ERIC Educational Resources Information Center

    Wittcoff, Harold A.

    1983-01-01

    Describes industrial acetaldehyde synthesis/uses, explaining why acetaldehyde usage is declining in industry. Includes a discussion of the reaction chemistry, equations, and molecular structure diagrams. (JM)

  19. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 January--31 March 1996

    SciTech Connect

    1996-04-20

    A series of CuMgCeO{sub x} catalysts have been prepared. Range of Cu dispersion, determined by N{sub 2}O titration, was 19-48% and are among the highest reported in the literature for Cu-based methanol and higher alcohol synthesis catalysts. Kinetics of MeOH and EtOH coupling reactions on Cu/ZnO and K-Cu/MgO/CeO{sub 2} catalysts indicate that Cu promotes alcohol dehydrogenation. Acetaldehyde is a reactive intermediate. High-pressure isobutanol synthesis studies have been carried out on K- and Cs-promoted Cu/MgO/CeO{sub 2} catalysts. The K promoter is more active than Cs for CO conversion, but the Cs promoter activates the C{sub 1} to C{sub 2} step more effectively. Catalysts with high alkali loading resulted in low conversions. Temperature programmed surface reaction studies of MeOH, EtOH, and acetaldehyde on MgO/CeO{sub 2}-based Cu catalysts show evolution of acetone, crotonaldehyde, methyl ethyl ketone, H2, carbon oxides. Neither EtOH nor acetaldehyde produces propionaldehyde or 1- propanol, suggesting that these C{sub 3} species can only form via reactions involving C{sub 1} and C{sub 2} oxygenate species.

  20. 27 CFR 21.93 - Acetaldehyde.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.93 Acetaldehyde. (a) Aldehyde content (as acetaldehyde). Not less than 95.0 percent by weight. (b)...

  1. 27 CFR 21.93 - Acetaldehyde.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.93 Acetaldehyde. (a) Aldehyde content (as acetaldehyde). Not less than 95.0 percent by weight. (b)...

  2. 27 CFR 21.93 - Acetaldehyde.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Acetaldehyde. 21.93 Section 21.93 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Acetaldehyde. (a) Aldehyde content (as acetaldehyde). Not less than 95.0 percent by weight. (b)...

  3. 27 CFR 21.93 - Acetaldehyde.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Acetaldehyde. 21.93 Section 21.93 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Acetaldehyde. (a) Aldehyde content (as acetaldehyde). Not less than 95.0 percent by weight. (b)...

  4. Methanol in dark clouds

    NASA Technical Reports Server (NTRS)

    Friberg, P.; Hjalmarson, A.; Madden, S. C.; Irvine, W. M.

    1988-01-01

    The first observation of methanol in cold dark clouds TMC 1, L 134 N, and B 335 is reported. In all three clouds, the relative abundance of methanol was found to be in the range of 10 to the -9th (i.e., almost an order of magnitude more abundant than acetaldehyde), with no observable variation between the clouds. Methanol emission showed a complex velocity structure; in TMC 1, clear indications of non-LTE were observed. Dimethyl ether was searched for in L 134 N; the upper limit of the column density of dimethyl ether in L 134 N was estimated to be 4 x 10 to the 12th/sq cm, assuming 5 K rotation temperature and LTE. This limit makes the abundance ratio (CH3)2O/CH3OH not higher than 1/5, indicating that dimethyl ether is not overabundant in this dark cloud.

  5. Production of acetaldehyde by Zymomonas mobilis

    SciTech Connect

    Wecker, M.S.A.; Zall, R.R.

    1987-12-01

    Mutants of Zymomonas mobilis were selected for decreased alcohol dehydrogenase activity by using consecutively higher concentration of allyl alcohol. A mutant selected by using 100 mM allyl alcohol produced acetaldehyde at a level of 4.08 g/liter when the organism was grown in aerated batch cultures on a medium containing 4.0% (wt/wt) glucose. On the basis of the amount of glucose utilized, this level of acetaldehyde production represents nearly 40% of the maximum theoretical yield. Acetaldehyde produced during growth was continuously air stripped from the reactor. Acetaldehyde present in the exhaust stream was then trapped as the acetaldehyde-bisulfite addition product in an aqueous solution of sodium bisulfite and released by treatment with base. Acetaldehyde was found to inhibit growth of Z. mobilis at concentrations as low as 0.05% (wt/wt) acetaldehyde. An acetaldehyde-tolerant mutant of Z. mobilis was isolated after both mutagenesis with nitrosoguanidine and selection in the presence of vapor-phase acetaldehyde. The production of acetaldehyde has potential advantages over that of ethanol: lower energy requirements for production separation, efficient separation of product from dilute feed streams, continuous separation of product from the reactor, and a higher marketplace value.

  6. Rubrene endoperoxide acetone monosolvate

    PubMed Central

    Shinashi, Kiyoaki; Uchida, Akira

    2012-01-01

    The title acetone solvate, C42H28O2·C3H6O [systematic name: 1,3,10,12-tetra­phenyl-19,20-dioxapenta­cyclo­[10.6.2.02,11.04,9.013,18]icosa-2(11),3,5,7,9,13,15,17-octa­ene acetone monosolvate], is a photooxygenation product of rubrene (systematic name: 5,6,11,12-tetra­phenyl­tetra­cene). The mol­ecule bends at the bridgehead atoms, which are linked by the O—O transannular bond, with a dihedral angle of 49.21 (6)° between the benzene ring and the naphthalene ring system of the tetra­cene unit. In the crystal, the rubrene mol­ecules are linked by C—H⋯O hydrogen bonds into a column along the c axis. The acetone solvent mol­ecules form a dimer around a crystallographic inversion centre through a carbon­yl–carbonyl dipolar inter­action. A C—H⋯O hydrogen bond between the rubrene and acetone mol­ecules is also observed. PMID:22590045

  7. Rubrene endoperoxide acetone monosolvate.

    PubMed

    Shinashi, Kiyoaki; Uchida, Akira

    2012-04-01

    The title acetone solvate, C(42)H(28)O(2)·C(3)H(6)O [systematic name: 1,3,10,12-tetra-phenyl-19,20-dioxapenta-cyclo-[10.6.2.0(2,11).0(4,9).0(13,18)]icosa-2(11),3,5,7,9,13,15,17-octa-ene acetone monosolvate], is a photooxygenation product of rubrene (systematic name: 5,6,11,12-tetra-phenyl-tetra-cene). The mol-ecule bends at the bridgehead atoms, which are linked by the O-O transannular bond, with a dihedral angle of 49.21 (6)° between the benzene ring and the naphthalene ring system of the tetra-cene unit. In the crystal, the rubrene mol-ecules are linked by C-H⋯O hydrogen bonds into a column along the c axis. The acetone solvent mol-ecules form a dimer around a crystallographic inversion centre through a carbon-yl-carbonyl dipolar inter-action. A C-H⋯O hydrogen bond between the rubrene and acetone mol-ecules is also observed. PMID:22590045

  8. Blood and liver acetaldehyde concentration in rats following acetaldehyde inhalation and intravenous and intragastric ethanol administration

    SciTech Connect

    Watanabe, A.; Hobara, N.; Nagashima, H.

    1986-10-01

    Ethanol is metabolized to acetaldehyde, a highly reactive product of ethanol oxidation. Ethanol might be blended with gasoline and used as a fuel in the future; biohazard of acetaldehyde inhalation must be discussed. Recent improvements in our ability to measure acetaldehyde levels in blood and various tissues have made the assessment of acetaldehyde's role in alcoholic organ intoxication possible. Blood and liver acetaldehyde concentrations in rats were reported as being linearly correlated following intragastric ethanol administration. Acetaldehyde was administered by inhalation to study its toxicity. However, liver concentrations following the inhalation was not investigated. The present communication describes the relationship between blood and liver acetaldehyde concentrations in rats following acetaldehyde inhalation and different routes of ethanol administration.

  9. Production of methanol from heat-stressed pepper and corn leaf disks

    SciTech Connect

    Anderson, J.A. . Dept. of Horticulture and Landscape Architecture)

    1994-05-01

    Early Calwonder'' pepper (Capsicum annuum L.) and Jubilee'' corn (Zea mays L.) leaf disks exposed to high temperature stress produced ethylene, ethane, methanol, acetaldehyde, and ethanol based on comparison of retention times during gas chromatography to authentic standards. Methanol, ethanol, and acetaldehyde were also identified by mass spectroscopy. Corn leaf disks produced lower levels of ethylene, ethane, and methanol, but more acetaldehyde and ethanol than pepper. Production of ethane, a by-product of lipid peroxidation, coincided with an increase in electrolyte leakage (EL) in pepper but not in corn. Compared with controls, pepper leaf disks infiltrated with linolenic acid evolved significantly greater amounts of ethane, acetaldehyde, and methanol and similar levels of ethanol. EL and volatile hydrocarbon production were not affected by fatty acid infiltration in corn. Infiltration of pepper leaves with buffers increasing in pH from 5.5 to 9.5 increased methanol production.

  10. Proton transfer in acetaldehyde and acetaldehyde-water clusters: Vacuum ultraviolet photoionization experiment and theoretical calculations

    NASA Astrophysics Data System (ADS)

    Kostko, Oleg; Troy, Tyler P.; Bandyopadhyay, Biswajit; Ahmed, Musahid

    2015-03-01

    Acetaldehyde, a probable human carcinogen and of environmental importance, upon solvation provides a test bed for understanding proton transfer pathways and catalytic mechanisms. In this study, we report on single photon vacuum ultraviolet photoionization of small acetaldehyde and acetaldehyde-water clusters. Appearance energies of protonated clusters are extracted from the experimental photoionization efficiency curves and compared to electronic structure calculations. The comparison of experimental data to computational results provides mechanistic insight into the fragmentation mechanisms of the observed mass spectra. Using deuterated water for isotopic tagging, we observe that proton transfer is mediated via acetaldehyde and not water in protonated acetaldehyde-water clusters.

  11. 27 CFR 21.93 - Acetaldehyde.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Acetaldehyde. 21.93 Section 21.93 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.93 Acetaldehyde. (a) Aldehyde content...

  12. Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

    PubMed Central

    Akgul Kalkan, Esin; Sahiner, Mehtap; Ulker Cakir, Dilek; Alpaslan, Duygu; Yilmaz, Selehattin

    2016-01-01

    Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365 nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15 cm × 4.6 mm × 3 μm) at retention time (tR) 12.10 min and flowrate of 1 mL min−1 using a (methanol/acetonitrile) water elution gradient. The methodology is simple, rapid, sensitive, and of low cost, exhibits good reproducibility, and allows the analysis of acetone in biological fluids. A calibration curve was obtained for acetone using its standard solutions in acetonitrile. Quantitative analysis of acetone in human blood was successfully carried out using this calibration graph. The applied method was validated in parameters of linearity, limit of detection and quantification, accuracy, and precision. We also present acetone as a useful tool for the HPLC-based metabolomic investigation of endogenous metabolism and quantitative clinical diagnostic analysis. PMID:27298750

  13. Methanol test

    MedlinePlus

    ... sources of methanol in the body include fruits, vegetables, and diet drinks that contain aspartame. Methanol is ... eat or drink it in toxic amounts. Methanol poisoning mainly affects the digestive system, nervous system, and ...

  14. Fate of acetone in water

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.

    1982-01-01

    The physical, chemical, and biological processes that might affect the concentration of acetone in water were investigated in laboratory studies. Processes considered included volatilization, adsorption by sediments, photodecomposition, bacterial degradation, and absorption by algae and molds. It was concluded that volatilization and bacterial degradation were the dominant processes determining the fate of acetone in streams and rivers. ?? 1982.

  15. Acetone-based cellulose solvent.

    PubMed

    Kostag, Marc; Liebert, Tim; Heinze, Thomas

    2014-08-01

    Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved.

  16. Methanol in dark clouds.

    PubMed

    Friberg, P; Madden, S C; Hjalmarson, A; Irvine, W M

    1988-01-01

    We report observations, for the first time, of the 2(0) - 1(0)A+ and E, 2(-1) - 1(-1) E, and 1(0) - 0(0)A+ lines of methanol (CH3OH) in three dark cold clouds, TMC1, L134N, and B335. The CH3OH emission is extended in these clouds and shows a complex velocity structure. Clear indications of non LTE excitation are observed in TMC 1. Estimated column densities are a few 10(13) cm-2. Although less abundant than formaldehyde (H2CO), methanol is almost an order of magnitude more abundant than acetaldehyde (CH3CHO), in these clouds. Dimethyl ether was searched for in L134N, to an upper limit of 4 10(12) cm-2 (3 sigma). Implications for dark cloud excitation and chemistry are discussed. A new, more accurate, rest frequency 96741.39(0.01) MHz is determined for the 2(0) - 1(0) A+ E line of methanol.

  17. Heterogeneous Interactions of Acetaldehyde and Sulfuric Acid

    NASA Technical Reports Server (NTRS)

    Michelsen, R. R.; Ashbourn, S. F. M.; Iraci, L. T.

    2004-01-01

    The uptake of acetaldehyde [CH3CHO] by aqueous sulfuric acid has been studied via Knudsen cell experiments over ranges of temperature (210-250 K) and acid concentration (40-80 wt. %) representative of the upper troposphere. The Henry's law constants for acetaldehyde calculated from these data range from 6 x 10(exp 2) M/atm for 40 wt. % H2SO4 at 228 K to 2 x 10(exp 5) M/atm for 80 wt. % H2SO4 at 212 K. In some instances, acetaldehyde uptake exhibits apparent steady-state loss. The possible sources of this behavior, including polymerization, will be explored. Furthermore, the implications for heterogeneous reactions of aldehydes in sulfate aerosols in the upper troposphere will be discussed.

  18. Decomposition of acetaldehyde : experiment and detailed theory.

    SciTech Connect

    Gupte, K. S.; Kiefer, J. H.; Tranter, R. S.; Klippenstein, S. J.; Harding, L. B.; Chemistry; Univ. of Illinois at Chicago

    2007-01-01

    The classic pyrolytic decomposition of acetaldehyde has been examined to the higher temperatures used in combustion and also lower pressures with 85 laser-schlieren, shock-tube measurements of density gradient covering 40-500 torr and 1550-2400 K. This work is supplemented and modeled with a CASPT2 based variable reaction coordinate RRKM prediction of the dissociation kinetics. These RRKM predictions are then incorporated in good two-dimensional master equation fits of the strong falloff seen in the laser-schlieren experiments, and also that shown in some previous shock-tube results using UV absorption of the acetaldehyde as diagnostic. The laser-schlieren data provide not only unambiguous dissociation rates but also solid indications of the secondary chemistry. Modeling of the full density gradient profiles offers good estimates of rates for H-atom abstraction from both the acetaldehyde and the HCO radical, again at high temperatures.

  19. Deployment of a Fast-GCMS System to Measure C2 to C5 Carbonyls, Methanol and Ethanol Aboard Aircraft

    NASA Technical Reports Server (NTRS)

    Apel, Eric C.

    2004-01-01

    Through funding of this proposal, a fast response gas chromatograph/mass spectrometer (FGCMS) instrument to measure less than or equal to C4 carbonyl compounds and methanol was developed for the NASA GTE TRACE-P (Global Tropospheric Experiment, Transport And Chemical Evolution Over The Pacific) mission. The system consists of four major components: sample inlet, preconcentration system, gas chromatograph (GC), and detector. The preconcentration system is a custom-built cryogen-conservative system. The GC is a compact, custom-built unit that can be temperature programmed and rapidly cooled. Detection is accomplished with an Agilent Technologies 5973 mass spectrometer. The FGCMS instrument provides positive identification because the compounds are chromatographically separated and mass selected. During TRACE-P, a sample was analyzed every 5 minutes. The FGCMS limit of detection was between 5 and 75 pptv, depending on the compound. The entire instrument package is contained in a standard NASA instrument rack (106 cm x 61 cm x 135 cm), consumes less than 1200 watts and is fully automated with LabViEW 6i. Methods were developed or producing highly accurate gas phase standards for the target compounds and for testing the system in the presence of potential interferents. This report presents data on these tests and on the general overall performance of the system in the laboratory and aboard the DC-8 aircraft during the mission. Vertical profiles for acetaldehyde, methanol, acetone, propanal, methyl ethyl ketone, and butanal from FGCMS data collected over the entire mission are also presented.

  20. Pharmacological treatments and strategies for reducing oral and intestinal acetaldehyde.

    PubMed

    Salaspuro, Ville

    2007-01-01

    Strong epidemiological, genetic and biochemical evidence indicates that local acetaldehyde exposure is a major factor behind gastrointestinal cancers especially associated with alcohol drinking and smoking. Thus, reducing the exposure to carcinogenic acetaldehyde either by decreasing the production or by eliminating acetaldehyde locally might offer a preventive strategy against acetaldehyde-induced gastrointestinal cancers. Thiol products, such as the amino acid cysteine, are known to be able to protect against acetaldehyde toxicity. Cysteine is able to bind acetaldehyde efficiently by forming a stable thiazolidine-carboxylic acid compound. Special cysteine preparations (such as lozenge and chewing gum) have already been developed to bind smoking and alcohol drinking derived acetaldehyde from the oral cavity. Most importantly, these type of drug formulations offer a novel method for intervention studies aimed to resolve the eventual role of acetaldehyde in the pathogenesis of upper digestive tract cancers. Acetaldehyde exposure could also be influenced by modifying the acetaldehyde producing microbiota. With regard to the upper digestive tract, acetaldehyde production from ingested ethanol could be significantly reduced by using an antiseptic mouthwash, chlorhexidine. In the large intestine acetaldehyde production could be markedly decreased either by reducing the Gram-negative microbes by ciprofloxacin antibiotic or by lowering the intraluminal pH by lactulose. PMID:17590993

  1. The Reactions of Acetone with the Surfaces of Uranium Dioxide Single Crystal and Thin Film

    SciTech Connect

    King,R.; Senanayake, S.; Chong, S.; Idriss, H.

    2007-01-01

    The reaction of acetone, as an example of a carbonyl compound, is studied over UO2 (1 1 1) single crystal and thin film surfaces. Over the stoichiometric single crystal surface, acetone is molecularly and weakly adsorbed with a computed activation energy for desorption in the range of 95-65 kJ/mol with pre-exponential factors between 1011 and 1013 s-1. On the contrary, acetone reacts very strongly on the O-defected single crystal and thin film surfaces. In addition to total decomposition evidence of aldolization and cyclization reactions were seen. The thin film of UO2 was studied by synchrotron light, providing high resolution photoelectron spectroscopy in the core level, and high sensitivity in the both the core and valence band regions. The U5f line was considerably enhanced at grazing angle when compared to that obtained at normal angle for the O-defected surface, showing that the surface is more reduced than the next layers. The U 4f lines indicated the presence of U cations in lower oxidation states than +4 for the O-defected surface. These lines were considerably attenuated upon adsorption of acetone, due to surface oxidation by C{double_bond}O bond dissociation. The reaction pathway for acetone on the O-defected surface is presented, and compared to that of the previously studied acetaldehyde molecule.

  2. Transport and intracellular accumulation of acetaldehyde in Saccharomyces cerevisiae

    SciTech Connect

    Stanley, G.A.; Pamment, N.B. )

    1993-06-05

    The rate of acetaldehyde efflux from yeast cells and its intracellular concentration were studied in the light of recent suggestions that acetaldehyde inhibition may be an important factor in yeast ethanol fermentations. When the medium surrounding cells containing ethanol and acetaldehyde was suddenly diluted, the rate of efflux of acetaldehyde was slow relative to the rate of ethanol efflux, suggesting that acetaldehyde, unlike ethanol, may accumulate intracellularly. Intracellular acetaldehyde concentrations were measured during high cell density fermentations, using direct injection gas chromatography to avoid the need to concentrate or disrupt the cells. Intracellular acetaldehyde concentrations substantially exceeded the extracellular concentrations throughout fermentation and were generally much higher than the acetaldehyde concentrations normally recorded in the culture broth in ethanol fermentations. The technique used was sensitive to the time taken to cool and freeze the samples. Measured intracellular acetaldehyde concentrations fell rapidly as the time taken to freeze the suspensions was extended beyond 2 s. The results add weight to recent claims that acetaldehyde toxicity is responsible for some of the effects previously ascribed to ethanol in alcohol fermentations, especially Zymomonas fermentations. Further work is required to confirm the importance of acetaldehyde toxicity under other culture conditions.

  3. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD... Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in...

  4. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  5. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  6. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  7. 21 CFR 173.210 - Acetone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice....

  8. Prebiotic synthesis of imidazole-4-acetaldehyde and histidine

    NASA Technical Reports Server (NTRS)

    Shen, Chun; Oro, J.; Yang, Lily; Miller, Stanley L.

    1987-01-01

    The prebiotic synthesis of imidazole-4-acetaldehyde and imidazole-4-glycol from erythrose and formamidine has been demonstrated as well as the prebiotic synthesis of imidazole-4-ethanol and imidazole-4-glycol from erythrose, formaldehyde, and ammonia. The maximum yields of imidazole-4-acetaldehyde, imidazole-4-ethanol, and imidazole-4-glycol obtained in these reactions are 1.6, 5.4, and 6.8 percent respectively, based on the erythrose. Imidazole-4-acetaldehyde would have been converted to histidine on the primitive earth by a Strecker synthesis, and several prebiotic reactions would convert imidazole-4-glycol and imidazole-4-ethanol to imidazole-4-acetaldehyde.

  9. Experimental and modeling study of the oxidation of acetaldehyde in an atmospheric-pressure pulsed corona discharge

    NASA Astrophysics Data System (ADS)

    Klett, C.; Touchard, S.; Vega-Gonzalez, A.; Redolfi, M.; Bonnin, X.; Hassouni, K.; Duten, X.

    2012-08-01

    This paper reports the results obtained for the degradation of acetaldehyde by an atmospheric plasma corona discharge working in a pulsed regime. It was shown that a few hundred ppm of acetaldehyde diluted in a pure N2 gas flow can be removed up to 80% by a discharge fed with an electric power lower than 1 W. Under the same conditions, adding up to 5% of O2 allowed the removal of up to 95% of the initial acetaldehyde. The main identified end products were CO2, CO and methanol. A quasi-homogeneous zero-dimensional chemical model was developed to investigate the respective efficiency of the discharge and post-discharge periods in the global removal of the pollutant. The identified main pathways of acetaldehyde degradation were quenching of N2 metastable states during plasma pulses and oxidation by O and OH radicals during the post-discharge. This latter contribution increased with input power because of ozone accumulation in the gas mixture acting as an additional oxygen reservoir.

  10. 40 CFR 721.10036 - Acetaldehyde based polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Acetaldehyde based polymer (generic... Specific Chemical Substances § 721.10036 Acetaldehyde based polymer (generic). (a) Chemical substance and... based polymer (PMN P-02-406) is subject to reporting under this section for the significant new...

  11. 40 CFR 721.10036 - Acetaldehyde based polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acetaldehyde based polymer (generic... Specific Chemical Substances § 721.10036 Acetaldehyde based polymer (generic). (a) Chemical substance and... based polymer (PMN P-02-406) is subject to reporting under this section for the significant new...

  12. 40 CFR 721.10036 - Acetaldehyde based polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acetaldehyde based polymer (generic... Specific Chemical Substances § 721.10036 Acetaldehyde based polymer (generic). (a) Chemical substance and... based polymer (PMN P-02-406) is subject to reporting under this section for the significant new...

  13. Catalytic oxidation of ethanol and acetaldehyde in supercritical carbon dioxide

    SciTech Connect

    Zhou, L.; Akgerman, A.

    1995-05-01

    Supercritical fluid (SCF) extraction has been receiving increasing attention for the remediation of environmental matrices contaminated with organic compounds. Catalytic oxidation of ethanol and acetaldehyde over a 4.45% Pt/TiO{sub 2} catalyst in supercritical carbon dioxide was studied in a 1/2 in. fixed bed reactor. Experiments for ethanol oxidation were performed at temperatures from 423 to 573 K and at a pressure of 8.96 MPa with a 5:1 molar ratio of oxygen to ethanol in the feed. Acetaldehyde oxidation was performed at temperatures from 423 to 548 K and at 8.96 MPa with an approximate 4.7:1 molar ratio of oxygen to acetaldehyde in the feed. In addition to CO{sub 2}, the complete oxidation product, acetaldehyde and trace amounts of CO were generated during ethanol oxidation, while a trace amount of CO was the only partial oxidation product during acetaldehyde oxidation. A parallel and consecutive reaction mechanism was postulated for ethanol oxidation, whereas dissociative adsorption of acetaldehyde on the catalyst surface and surface reaction rate control were postulated for acetaldehyde oxidation. The kinetic parameters in the rate expressions based on the mechanisms were obtained by fitting the experimental data with the results of the model calculation. The models were used to predict the conversion and yield for ethanol oxidation and acetaldehyde oxidation.

  14. Gene specific modifications unravel ethanol and acetaldehyde actions

    PubMed Central

    Israel, Yedy; Rivera-Meza, Mario; Karahanian, Eduardo; Quintanilla, María E.; Tampier, Lutske; Morales, Paola; Herrera-Marschitz, Mario

    2013-01-01

    Ethanol is metabolized into acetaldehyde mainly by the action of alcohol dehydrogenase in the liver, while mainly by the action of catalase in the brain. Aldehyde dehydrogenase-2 metabolizes acetaldehyde into acetate in both organs. Gene specific modifications reviewed here show that an increased liver generation of acetaldehyde (by transduction of a gene coding for a high-activity liver alcohol dehydrogenase ADH1*B2) leads to increased blood acetaldehyde levels and aversion to ethanol in animals. Similarly aversive is an increased acetaldehyde level resulting from the inhibition of liver aldehyde dehydrogenase-2 (ALDH2) synthesis (by an antisense coding gene against aldh2 mRNA). The situation is diametrically different when acetaldehyde is generated in the brain. When the brain ventral tegmental area (VTA) is endowed with an increased ability to generate acetaldehyde (by transfection of liver rADH) the reinforcing effects of ethanol are increased, while a highly specific inhibition of catalase synthesis (by transduction of a shRNA anti catalase mRNA) virtually abolishes the reinforcing effects of ethanol as seen by a complete abolition of ethanol intake in rats bred for generations as high ethanol drinkers. Data shows two divergent effects of increases in acetaldehyde generation: aversive in the periphery but reinforcing in the brain. PMID:23847486

  15. Biochemical basis of mitochondrial acetaldehyde dismutation in Saccharomyces cerevisiae.

    PubMed Central

    Thielen, J; Ciriacy, M

    1991-01-01

    As reported previously, Saccharomyces cerevisiae cells deficient in all four known genes coding for alcohol dehydrogenases (ADH1 through ADH4) produce considerable amounts of ethanol during aerobic growth on glucose. It has been suggested that ethanol production in such adh0 cells is a corollary of acetaldehyde dismutation in mitochondria. This could be substantiated further by showing that mitochondrial ethanol formation requires functional electron transport, while the proton gradient or oxidative phosphorylation does not interfere with reduction of acetaldehyde in isolated mitochondria. This acetaldehyde-reducing activity is different from classical alcohol dehydrogenases in that it is associated with the inner mitochondrial membrane and also is unable to carry out ethanol oxidation. The putative cofactor is NADH + H+ generated by a soluble, matrix-located aldehyde dehydrogenase upon acetaldehyde oxidation to acetate. This enzyme has been purified from mitochondria of glucose-grown cells. It is clearly different from the known mitochondrial aldehyde dehydrogenase, which is absent in glucose-grown cells. Both acetaldehyde-reducing and acetaldehyde-oxidizing activities are also present in the mitochondrial fraction of fermentation-proficient (ADH+) cells. Mitochondrial acetaldehyde dismutation may have some significance in the removal of surplus acetaldehyde and in the formation of acetate in mitochondria during aerobic glucose fermentation. Images FIG. 4 PMID:1938903

  16. 40 CFR 721.10036 - Acetaldehyde based polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acetaldehyde based polymer (generic... Specific Chemical Substances § 721.10036 Acetaldehyde based polymer (generic). (a) Chemical substance and... based polymer (PMN P-02-406) is subject to reporting under this section for the significant new...

  17. 40 CFR 721.10036 - Acetaldehyde based polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acetaldehyde based polymer (generic... Specific Chemical Substances § 721.10036 Acetaldehyde based polymer (generic). (a) Chemical substance and... based polymer (PMN P-02-406) is subject to reporting under this section for the significant new...

  18. Acetaldehyde photochemistry on TiO2(110)

    SciTech Connect

    Zehr, Robert T.; Henderson, Michael A.

    2008-07-01

    The ultraviolet (UV) photon induced decomposition of acetaldehyde absorbed on the oxidized retile TIO2(110) surface was studied with photon stimulated desorption (PSD) and theral programmed desorption (TPD). Acetaldehyde desorbs molecularly from TiO2(110) with minor decomposition channels yielding butene on the reduced TiO2 surface and acetate on the oxidized TiO2 surface. Acetaldehyde absorbed on oxidized TiO2(110) undergoes a facile thermal reaction to form a photoactive acetaldehyde-oxygen complex. UV irradiation of the acetaldehyde-oxygen complex resulting in the ejection of methyl radical into gas phase and conversion of the surface bound fragment to formate.

  19. Acetaldehyde Photochemistry on TiO2(110)

    SciTech Connect

    Zehr, Robert T.; Henderson, Michael A.

    2008-07-01

    The ultraviolet (UV) photon induced decomposition of acetaldehyde adsorbed on the oxidized rutile TiO2(110) surface was studied with photon stimulated desorption (PSD) and thermal programmed desorption (TPD). Acetaldehyde desorbs molecularly from TiO2(110) with minor decomposition channels yielding butene on the reduced TiO2 surface and acetate on the oxidized TiO2 surface. Acetaldehyde adsorbed on oxidized TiO2(110) undergoes a facile thermal reaction to form a photoactive acetaldehyde-oxygen complex. UV irradiation of the acetaldehyde-oxygen complex initiated photofragmentation of the complex resulting in the ejection of methyl radical into gas phase and conversion of the surface bound fragment to formate.

  20. Complex oscillations in the combustion of acetaldehyde

    SciTech Connect

    Harding, R.H.; Sevcikova, H.; Ross, J.

    1988-10-15

    Aperiodic dynamics are observed experimentally in the cool flame combustion region of acetaldehyde (ACH) in a continuous stirred tank reactor (CSTR). A gradual transition is seen, with variation of exit orifice size, from limit cycle oscillation to aperiodic variations in light emission, and then back to near periodic oscillations. We analyze this transition by calculating power spectra, autocorrelation functions, phase portraits, period distributions, and Poincare sections. The variation in peak amplitude and peak-to-peak period of the temporal variations of light emission increases during the transition. There are many initial indications of a transition to chaos. However, after an in-depth analysis, given in the following article, we ascribe the transition to the presence of a Hopf bifurcation and noise: the path traced out in the constraint space by the change in exit orifice size is nearly tangent to a Hopf bifurcation set but does not cross this set.

  1. Complex oscillations in the combustion of acetaldehyde

    NASA Astrophysics Data System (ADS)

    Harding, Robert H.; Sevčikova, Hana; Ross, John

    1988-10-01

    Aperiodic dynamics are observed experimentally in the cool flame combustion region of acetaldehyde (ACH) in a continuous stirred tank reactor (CSTR). A gradual transition is seen, with variation of exit orifice size, from limit cycle oscillation to aperiodic variations in light emission, and then back to near periodic oscillations. We analyze this transition by calculating power spectra, autocorrelation functions, phase portraits, period distributions, and Poincaré sections. The variation in peak amplitude and peak-to-peak period of the temporal variations of light emission increases during the transition. There are many initial indications of a transition to chaos. However, after an in-depth analysis, given in the following article, we ascribe the transition to the presence of a Hopf bifurcation and noise: the path traced out in the constraint space by the change in exit orifice size is nearly tangent to a Hopf bifurcation set but does not cross this set.

  2. New insights in understanding plasma-catalysis reaction pathways: study of the catalytic ozonation of an acetaldehyde saturated Ag/TiO2/SiO2 catalyst

    NASA Astrophysics Data System (ADS)

    Sauce, Sonia; Vega-González, Arlette; Jia, Zixian; Touchard, Sylvain; Hassouni, Khaled; Kanaev, Andrei; Duten, Xavier

    2015-07-01

    This paper is a preliminary study intended to straighten out the role of reactive oxygen species in the activation mechanisms occurring in a plasma driven catalysis process for acetaldehyde decomposition. For this purpose, the interaction between the surface, the pollutant and one of the main oxidative species generated by non-thermal plasma, namely ozone, was studied. Acetaldehyde catalytic ozonation over a nanostructured Ag/TiO2/SiO2 catalyst is carried out at room temperature and atmospheric pressure, and followed by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). For this, the catalyst is firstly saturated with acetaldehyde. At the end of the saturation, acetaldehyde and crotonaldehyde, its condensation product, are identified as the major adsorbed species. In a second step, the surface ozonation is carried out and three additional intermediates are identified, namely, acetone, formic acid and acetic acid. Gaseous CO, CO2, methyl formate and methyl acetate are detected at the DRIFTS outlet, evidencing the partial mineralization of the adsorbed species. A global reaction scheme is proposed for explaining the formation of those adsorbed intermediates and gaseous products. This proposed heterogeneous ozone induced chemistry has to be taken into account when associating non-thermal plasma in air to a catalyst. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  3. Piecing together the puzzle of acetaldehyde as a neuroactive agent.

    PubMed

    Correa, Mercè; Salamone, John D; Segovia, Kristen N; Pardo, Marta; Longoni, Rosanna; Spina, Liliana; Peana, Alessandra T; Vinci, Stefania; Acquas, Elio

    2012-01-01

    Mainly known for its more famous parent compound, ethanol, acetaldehyde was first studied in the 1940s, but then research interest in this compound waned. However, in the last two decades, research on acetaldehyde has seen a revitalized and uninterrupted interest. Acetaldehyde, per se, and as a product of ethanol metabolism, is responsible for many pharmacological effects which are not clearly distinguishable from those of its parent compound, ethanol. Consequently, the most recent advances in acetaldehyde's psychopharmacology have been inspired by the experimental approach to test the hypothesis that some of the effects of ethanol are mediated by acetaldehyde and, in this regard, the characterization of metabolic pathways for ethanol and the localization within discrete brain regions of these effects have revitalized the interest on the role of acetaldehyde in ethanol's central effects. Here we present and discuss a wealth of experimental evidence that converges to suggest that acetaldehyde is an intrinsically active compound, is metabolically generated in the brain and, finally, mediates many of the psychopharmacological properties of ethanol.

  4. Student Preparation of Acetone from 2-Propanol.

    ERIC Educational Resources Information Center

    Kauffman, J. M.; McKee, J. R.

    1982-01-01

    Background information, procedures, and materials needed are provided for an experiment in which acetone is produced from 2-propanol. The experiment does not use magnetic stirring, avoids the necessity for exhaustive extractions with ether, and produces a 60-percent yield of redistilled acetone within a two-and-one-half-hour laboratory period.…

  5. Multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase causing excessive acetaldehyde production from ethanol by oral streptococci.

    PubMed

    Pavlova, Sylvia I; Jin, Ling; Gasparovich, Stephen R; Tao, Lin

    2013-07-01

    Ethanol consumption and poor oral hygiene are risk factors for oral and oesophageal cancers. Although oral streptococci have been found to produce excessive acetaldehyde from ethanol, little is known about the mechanism by which this carcinogen is produced. By screening 52 strains of diverse oral streptococcal species, we identified Streptococcus gordonii V2016 that produced the most acetaldehyde from ethanol. We then constructed gene deletion mutants in this strain and analysed them for alcohol and acetaldehyde dehydrogenases by zymograms. The results showed that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol and ethanol, respectively. Two additional dehydrogenases, S-AdhA and TdhA, were identified with specificities to the secondary alcohol 2-propanol and threonine, respectively, but not to ethanol. S. gordonii V2016 did not show a detectable acetaldehyde dehydrogenase even though its adhE gene encodes a putative bifunctional acetaldehyde/alcohol dehydrogenase. Mutants with adhE deletion showed greater tolerance to ethanol in comparison with the wild-type and mutant with adhA or adhB deletion, indicating that AdhE is the major alcohol dehydrogenase in S. gordonii. Analysis of 19 additional strains of S. gordonii, S. mitis, S. oralis, S. salivarius and S. sanguinis showed expressions of up to three alcohol dehydrogenases, but none showed detectable acetaldehyde dehydrogenase, except one strain that showed a novel ALDH. Therefore, expression of multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase may contribute to excessive production of acetaldehyde from ethanol by certain oral streptococci.

  6. The combined oxidation of methanol and ethanol on silver catalysts

    SciTech Connect

    Kurina, L.N.; Gryaznov, V.M.; Gul yanova, S.G.; Plakidkin, A.A.; Vedernikov, V.I.

    1985-10-01

    The authors study the oxidation of methanol, ethanol, and mixtures of these alcohols on industrial silver-pumice and silver membrane catalysts as well as the adsorption of these alcohols on silver. The oxidation of the alcohol mixture on the industrial silver-pumice catalyst gives higher yields of both formaldehyde and acetaldehyde than in the oxidation of the alcohols taken individually. It is also shown that an increase in the rates of formaldehyde formation in the combined oxidation of methanol and ethanol was observed on the silver membrane catalyst.

  7. Mutagenic and cytotoxic activities of Limonium globuliferum methanol extracts.

    PubMed

    Eren, Yasin

    2016-10-01

    Unmonitored use of plant extractions alone or in combination with drugs may cause important health problems and toxic effects. Limonium (Plumbaginaceae) plants are known as antibacterial, anticancer and antivirus agent. But it is possible that this genus may have toxic effects. This study evaluated the mutagenic and cytotoxic effects of Limonium globuliferum (Boiss. et Heldr.) O. Kuntze (Plumbaginaceae) acetone/methanol (2:1), and methanol extracts of root, stem, and leaf. Different parts of this species were used in order to compare the mutagenic and cytotoxic effects of these parts. Ames test was carried out with S. typhimurium TA98, and TA100 strains. Strains were incubated at 37 °C for 72 h. MDBK cell line was used in MTT test. 10,000, 1000, 100, 10, 1 and 0.1 µg/plate concentrations of plant extracts were used in Ames test. 50, 25, 12.5, 6.25 and 3.125 µg/ml concentrations of root, stem and leaf acetone/methanol (2:1) and methanol extracts were used in MTT test. Ames test results indicated that only methanol leaf extract (10,000 µg/plate) had mutagenic activity. L. globuliferum root methanol extracts (3.125 and 6.25 µg/ml) increased the proliferation rates. Root acetone/methanol (2:1) extracts were found highly cytotoxic in all treatments. The results indicated that leaf extracts had lower cytotoxic effects than root and stem extracts. High concentrations of L. globuliferum stem and leaf methanol extracts showed cytotoxic activity in all treatment periods while low concentrations of the stem methanol extracts increased the proliferation rates.

  8. Photocatalyzed oxidation of ethanol and acetaldehyde in humidified air

    SciTech Connect

    Sauer, M.L.; Ollis, D.F.

    1996-02-01

    Photocatalysis is considered as a potential air treatment and purification technology. Photocatalyzed oxidation of ethanol and acetaldehyde in humidified air was carried out to establish a first complete kinetic model for a photocatalyzed multispecies network. Two photocatalysts were examined in a batch, recirculation reactor, near-UV illuminated TiO{sub 2} (anatase) coated (i) on the surface of a nonporous quartz glass plate and (ii) on a porous ceramic honeycomb monolith. The former contained only illuminated (active) surfaces, the latter consisted of substantial {open_quotes}dark{close_quotes} surfaces coated with a thin layer of illuminated (active) catalyst. Ethanol was photooxidized to acetaldehyde and formaldehyde intermediates, and eventually to carbon dioxide and water products. The catalyst and monolith surfaces adsorbed appreciable fractions of the trace ethanol, acetaldehyde, formaldehyde, carbon dioxide and water present. Ethanol, acetaldehyde, and carbon dioxide adsorption isotherms were measured on both catalysts; the formaldehyde adsorption isotherms were assumed identical to those of acetaldehyde. On the fully illuminated glass plate reactor, all four species were accounted for, and closure of a transient carbon mass balance was demonstrated. Completion of a transient carbon mass balance on the monolith reactor required inclusion of additional reaction intermediates (acetic and formic acids), which appear to reversibly accumulate on only the dark surfaces. The ethanol and acetaldehyde photocatalyzed oxidation kinetic networks were modeled using Langmuir-Hinshelwood rate forms combined with adsorption isotherms for reactant, intermediates, and product CO{sub 2}. For both the quartz plate and monolith catalysts, satisfactory kinetic models were developed to predict the entire time course of ethanol and acetaldehyde multicomponent batch conversions. 43 refs., 16 figs.

  9. Acetaldehyde exchange above a managed temperate mountain grassland.

    PubMed

    Hörtnagl, L; Bamberger, I; Graus, M; Ruuskanen, T M; Schnitzhofer, R; Walser, M; Unterberger, A; Hansel, A; Wohlfahrt, G

    2013-10-01

    An overview of acetaldehyde exchange above a managed temperate mountain grassland in Austria over four growing seasons is presented. The meadow acted as a net source of acetaldehyde in all four years, emitting between 7 and 28 mg C m(-2) over the whole growing period. The cutting of the meadow resulted in huge acetaldehyde emission bursts on the day of harvesting or one day later. During undisturbed conditions, both uptake and emission fluxes were recorded. The bidirectional nature of acetaldehyde fluxes was also reflected by clear diurnal cycles during certain time periods, indicating strong deposition processes before the 1st cut and emission towards the end of the growing season. The analysis of acetaldehyde compensation points revealed a complex relationship between ambient acetaldehyde mixing ratios and respective fluxes, significantly influenced by multiple environmental parameters and variable throughout the year. As a major finding of this study, we identified both a positive and negative correlation between concentration and flux on a daily scale, where soil temperature and soil water content were the most significant factors in determining the direction of the slope. In turn, this bidirectional relationship on a daily scale resulted in compensation points between 0.40 ppbv and 0.54 ppbv, which could be well explained by collected ancillary data. We conclude that in order to model acetaldehyde fluxes at the site in Neustift on a daily scale over longer time periods, it is crucial to know the type of relationship, i.e. the direction of the slope, between mixing ratios and fluxes on a given day.

  10. Acetaldehyde exchange above a managed temperate mountain grassland

    PubMed Central

    Hörtnagl, L.; Bamberger, I.; Graus, M.; Ruuskanen, T. M.; Schnitzhofer, R.; Walser, M.; Unterberger, A.; Hansel, A.; Wohlfahrt, G.

    2013-01-01

    An overview of acetaldehyde exchange above a managed temperate mountain grassland in Austria over four growing seasons is presented. The meadow acted as a net source of acetaldehyde in all four years, emitting between 7 and 28 mg C m−2 over the whole growing period. The cutting of the meadow resulted in huge acetaldehyde emission bursts on the day of harvesting or one day later. During undisturbed conditions, both uptake and emission fluxes were recorded. The bidirectional nature of acetaldehyde fluxes was also reflected by clear diurnal cycles during certain time periods, indicating strong deposition processes before the 1st cut and emission towards the end of the growing season. The analysis of acetaldehyde compensation points revealed a complex relationship between ambient acetaldehyde mixing ratios and respective fluxes, significantly influenced by multiple environmental parameters and variable throughout the year. As a major finding of this study, we identified both a positive and negative correlation between concentration and flux on a daily scale, where soil temperature and soil water content were the most significant factors in determining the direction of the slope. In turn, this bidirectional relationship on a daily scale resulted in compensation points between 0.40 ppbv and 0.54 ppbv, which could be well explained by collected ancillary data. We conclude that in order to model acetaldehyde fluxes at the site in Neustift on a daily scale over longer time periods, it is crucial to know the type of relationship, i.e. the direction of the slope, between mixing ratios and fluxes on a given day. PMID:24363666

  11. Biotransformation of ethanol to acetaldehyde by wild and mutant strains of methylotrophic yeast

    SciTech Connect

    Moroz, O.M.; Sibirnyi, A.A.; Ksheminskaya, G.P. |

    1995-05-01

    The conversion of ethanol to acetaldehyde by intact cells of wild and mutant strains of methylotrophic yeast Hansenula polymorpha was studied. It was established that mutations that lower the activity of aldehyde reductase and acetaldehyde dehydrogenase stimulate acetaldehyde accumulation. The highest accumulation of acetaldehyde was found in a mutant that possessed increased alcohol oxidase activity in growth on a medium with glucose. A decrease in formaldehyde dehydrogenase did not stimulate acetaldehyde accumulation. Bioconversion of ethanol to acetaldehyde was most effective at lowered temperatures due to marked suppression of catabolic alcohol oxidase inactivation, but not to the activity of this enzyme under indicated conditions. 27 refs., 4 figs., 3 tabs.

  12. Decarboxylation of Pyruvate to Acetaldehyde for Ethanol Production by Hyperthermophiles

    PubMed Central

    Eram, Mohammad S.; Ma, Kesen

    2013-01-01

    Pyruvate decarboxylase (PDC encoded by pdc) is a thiamine pyrophosphate (TPP)-containing enzyme responsible for the conversion of pyruvate to acetaldehyde in many mesophilic organisms. However, no pdc/PDC homolog has yet been found in fully sequenced genomes and proteomes of hyper/thermophiles. The only PDC activity reported in hyperthermophiles was a bifunctional, TPP- and CoA-dependent pyruvate ferredoxin oxidoreductase (POR)/PDC enzyme from the hyperthermophilic archaeon Pyrococcus furiosus. Another enzyme known to be involved in catalysis of acetaldehyde production from pyruvate is CoA-acetylating acetaldehyde dehydrogenase (AcDH encoded by mhpF and adhE). Pyruvate is oxidized into acetyl-CoA by either POR or pyruvate formate lyase (PFL), and AcDH catalyzes the reduction of acetyl-CoA to acetaldehyde in mesophilic organisms. AcDH is present in some mesophilic (such as clostridia) and thermophilic bacteria (e.g., Geobacillus and Thermoanaerobacter). However, no AcDH gene or protein homologs could be found in the released genomes and proteomes of hyperthermophiles. Moreover, no such activity was detectable from the cell-free extracts of different hyperthermophiles under different assay conditions. In conclusion, no commonly-known PDCs was found in hyperthermophiles. Instead of the commonly-known PDC, it appears that at least one multifunctional enzyme is responsible for catalyzing the non-oxidative decarboxylation of pyruvate to acetaldehyde in hyperthermophiles. PMID:24970182

  13. Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Sinha, V.; Kumar, V.; Rupakheti, M.; Panday, A.; Mahata, K. S.; Rupakheti, D.; Kathayat, B.; Lawrence, M. G.

    2015-09-01

    The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the Valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012-2013, a comprehensive study was carried out to characterize the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs by deploying a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS)-the first such deployment in South Asia. 71 ion peaks (for which measured ambient concentrations exceeded the 2 σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the Valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m/Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The highest average VOC mixing ratios during the measurement period were (in rank order): acetaldehyde (8.8 ppb), methanol (7.4 ppb), acetone (4.2 ppb), benzene (2.7 ppb), toluene (1.5 ppb), isoprene (1.1 ppb), acetonitrile (1.1 ppb), C8-aromatics (~ 1 ppb), furan (~ 0.5 ppb), and C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m/z = 69.070) and furan (m/z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde (~ 9 ppb), acetonitrile (~ 1 ppb) and isoprene (~ 1 ppb) to be among the highest reported till date. Two "new" ambient compounds namely, formamide (m/z = 46.029) and acetamide (m/z = 60.051), which can photochemically produce isocyanic

  14. Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

    NASA Astrophysics Data System (ADS)

    Sarkar, Chinmoy; Sinha, Vinayak; Kumar, Vinod; Rupakheti, Maheswar; Panday, Arnico; Mahata, Khadak S.; Rupakheti, Dipesh; Kathayat, Bhogendra; Lawrence, Mark G.

    2016-03-01

    The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012-2013, a comprehensive study was carried out to characterise the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs, by deploying a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) - the first such deployment in South Asia. In the study, 71 ion peaks (for which measured ambient concentrations exceeded the 2σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m / Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The concentration ranking in the average VOC mixing ratios during our wintertime deployment was acetaldehyde (8.8 ppb) > methanol (7.4 ppb) > acetone + propanal (4.2 ppb) > benzene (2.7 ppb) > toluene (1.5 ppb) > isoprene (1.1 ppb) > acetonitrile (1.1 ppb) > C8-aromatics ( ˜ 1 ppb) > furan ( ˜ 0.5 ppb) > C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m / z = 69.070) and furan (m / z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde ( ˜ 9 ppb), acetonitrile ( ˜ 1 ppb) and isoprene ( ˜ 1 ppb) to be among the highest reported to date. Two "new" ambient compounds, namely formamide (m / z = 46.029) and acetamide (m / z

  15. Alcohol and Acetaldehyde in Public Health: From Marvel to Menace

    PubMed Central

    Guo, Rui; Ren, Jun

    2010-01-01

    Alcohol abuse is a serious medical and social problem. Although light to moderate alcohol consumption is beneficial to cardiovascular health, heavy drinking often results in organ damage and social problems. In addition, genetic susceptibility to the effect of alcohol on cancer and coronary heart disease differs across the population. A number of mechanisms including direct the toxicity of ethanol, its metabolites [e.g., acetaldehyde and fatty acid ethyl esters (FAEEs)] and oxidative stress may mediate alcoholic complications. Acetaldehyde, the primary metabolic product of ethanol, is an important candidate toxin in developing alcoholic diseases. Meanwhile, free radicals produced during ethanol metabolism and FAEEs are also important triggers for alcoholic damages. PMID:20617031

  16. Bacterial degradation of acetone in an outdoor model stream

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

    1993-01-01

    Diurnal variations of the acetone concentration in an outdoor model stream were measured with and without a nitrate supplement to determine if the nitrate supplement would stimulate bacterial degradation of the acetone. Acetone loss coefficients were computed from the diurnal data using a fitting procedure based on a Lagrangian particle model. The coefficients indicated that bacterial degradation of the acetone was occurring in the downstream part of the stream during the nitrate addition. However, the acetone concentrations stabilized at values considerably above the limit of detection for acetone determination, in contrast to laboratory respirometer studies where the acetone concentration decreased rapidly to less than the detection limit, once bacterial acclimation to the acetone had occurred. One possible explanation for the difference in behavior was the limited 6-hour residence time of the acetone in the model stream.

  17. BIOGENIC SOURCES FOR FORMALDEHYDE AND ACETALDEHYDE DURING SUMMER MONTHS

    EPA Science Inventory

    Photochemical modeling estimated contributions to ambient concentrations of formaldehyde and acetaldehyde from biogenic emissions over the continental United States during January 2001 (Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstract A52B-0117). Results showed that maximum co...

  18. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  19. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  20. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  1. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  2. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... proportions of higher polymers, manufactured by reaction of hydrogen peroxide and acetone. (b) The additive...; or (2) approximately 0.75 gram of hydrogen peroxide equivalent per 100 grams of the additive, plus... agent in bread and roll production at not to exceed the quantity of hydrogen peroxide...

  3. [Methanol metabolism in plants].

    PubMed

    Stepanov, S S; Zolotar'ova, O K

    2011-01-01

    Methabolism of methanol in plant organisms is considered in the paper. Enzymes of consecutive oxidation of methanol and enzymes responsible for incorporation of carbon from methanol molecule to methyl groups of phospholipids, carboxylic acids and carbohydrates have been described. The peculiarity of plant organisms is in interaction of reactions of methanol transformation with pathways of photorespiration and C1-metabolism and in the capacity to use methanol carbon to form organic matter through photosynthesis. The inclusion of methanol metabolites in anabolic processes occurs at the level of formaldehyde and formiate. As a result, exogenous methanol at low concentrations can stimulate the photosynthetic efficiency of plants.

  4. Breath acetone analyzer: diagnostic tool to monitor dietary fat loss.

    PubMed

    Kundu, S K; Bruzek, J A; Nair, R; Judilla, A M

    1993-01-01

    Acetone, a metabolite of fat catabolism, is produced in excessive amounts in subjects on restricted-calorie weight-loss programs. Breath acetone measurements are useful as a motivational tool during dieting and for monitoring the effectiveness of weight-loss programs. We have developed a simple, easy-to-read method that quantifies the amount of acetone in a defined volume of exhaled breath after trapping the sample in a gas-analyzer column. The concentration of acetone, as measured by the length of a blue color zone in the analyzer column, correlates with results obtained by gas chromatography. Using the breath acetone analyzer to quantify breath acetone concentrations of dieting subjects, we established a correlation between breath acetone concentration and rate of fat loss (slope 52.2 nmol/L per gram per day, intercept 15.3 nmol/L, n = 78, r = 0.81). We also discussed the possibility of using breath acetone in diabetes management.

  5. Differential contribution of clinical amounts of acetaldehyde to skeletal and cardiac muscle dysfunction in alcoholic myopathy.

    PubMed

    Oba, Toshiharu; Maeno, Yoshitaka; Ishida, Kazuto

    2005-01-01

    Acute intoxication due to alcohol consumption has been known to elicit reversible skeletal and cardiac muscle dysfunction, or "alcoholic myopathy and cardiomyopathy". Sometimes, irreversible muscle damage can be induced after heavy alcohol drinking. Many researchers have proposed that acetaldehyde, the major oxidised product of alcohol, may be a primary factor underlying alcohol-induced muscle dysfunction. Because acetaldehyde is rapidly metabolised to acetate by aldehyde dehydrogenase (ALDH) mainly in the liver, blood concentration of acetaldehyde is maintained at a low level even after heavy alcohol intoxication. In alcoholics, blood acetaldehyde level is relatively high, probably due to hepatic inhibition of ALDH activity. Several mM of acetaldehyde have been used for studies of cardiac muscle contraction, the intracellular calcium transient, and the L-type calcium channel. In skeletal muscle, the calcium release channel/ryanodine receptor activity has been reported to be inhibited by exposure to 1 mM acetaldehyde. However, these observations were made using potentially lethal concentrations of acetaldehyde, so the hypothesis that acetaldehyde plays a crucial role on alcoholic myopathy is questionable. In this review, we will summarise the effect of alcohol and its major oxidised product, acetaldehyde, on skeletal and heart muscles and propose a toxic contribution of clinical concentrations of acetaldehyde to alcoholic myopathy. In addition, this review will include briefly the effect of acetaldehyde on diabetic cardiomyopathy.

  6. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  7. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  8. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  9. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  10. 46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is...

  11. Acetone-butanol fermentation of marine macroalgae.

    PubMed

    Huesemann, Michael H; Kuo, Li-Jung; Urquhart, Lindsay; Gill, Gary A; Roesijadi, Guri

    2012-03-01

    The objective of this study was to subject mannitol, either as a sole carbon source or in combination with glucose, and aqueous extracts of the kelp Saccharina spp., containing mannitol and laminarin, to acetone-butanol fermentation by Clostridium acetobutylicum (ATCC 824). Both mannitol and glucose were readily fermented. Mixed substrate fermentations with glucose and mannitol resulted in diauxic growth of C. acetobutylicum with glucose depletion preceding mannitol utilization. Fermentation of kelp extract exhibited triauxic growth, with an order of utilization of free glucose, mannitol, and bound glucose, presumably laminarin. The lag in laminarin utilization reflected the need for enzymatic hydrolysis of this polysaccharide into fermentable sugars. The butanol and total solvent yields were 0.12 g/g and 0.16 g/g, respectively, indicating that significant improvements are still needed to make industrial-scale acetone-butanol fermentations of seaweed economically feasible.

  12. Photodegradation of acetone in dilute aqueous solution

    SciTech Connect

    Stefan, M.I.; Bolton, J.R.

    1995-12-31

    Photochemical methods for destroying organic pollutants found in industrial wastewaters and groundwaters are being used successfully in environment treatment systems. This study focuses on acetone photodegradation in aqueous solution by UV irradiation (1 kW medium pressure Hg lamp) in the presence and absence of H{sub 2}O{sub 2}. Intermediates such as acetic and formic acids were detected. The kinetic data were evaluated and the reaction mechanisms were postulated considering the influence of oxygen concentration and pH. The generation of {sm_bullet}OH radicals from the photolysis of H{sub 2}O{sub 2} induces a faster decomposition of acetone (depending on H{sub 2}O{sub 2} concentration) than does direct photolysis.

  13. Mesoporous Silica Nanoparticle-Stabilized and Manganese-Modified Rhodium Nanoparticles as Catalysts for Highly Selective Synthesis of Ethanol and Acetaldehyde from Syngas

    SciTech Connect

    Huang, Yulin; Deng, Weihua; Guo, Enruo; Chung, Po-Wen; Chen, Senniang; Trewyn, Brian; Brown, Robert; Lin, Victor

    2012-03-30

    Well-defined and monodispersed rhodium nanoparticles as small as approximately 2 nm were encapsulated in situ and stabilized in a mesoporous silica nanoparticle (MSN) framework during the synthesis of the mesoporous material. Although both the activity and selectivity of MSN-encapsulated rhodium nanoparticles in CO hydrogenation could be improved by the addition of manganese oxide as expected, the carbon selectivity for C2 oxygenates (including ethanol and acetaldehyde) was unprecedentedly high at 74.5 % with a very small amount of methanol produced if rhodium nanoparticles were modified by manganese oxide with very close interaction.

  14. Formaldehyde and acetaldehyde emissions from residential wood combustion in Portugal

    NASA Astrophysics Data System (ADS)

    Cerqueira, Mário; Gomes, Luís; Tarelho, Luís; Pio, Casimiro

    2013-06-01

    A series of experiments were conducted to characterize formaldehyde and acetaldehyde emissions from residential combustion of common wood species growing in Portugal. Five types of wood were investigated: maritime pine (Pinus pinaster), eucalyptus (Eucalyptus globulus), cork oak (Quercus suber), holm oak (Quercus rotundifolia) and pyrenean oak (Quercus pyrenaica). Laboratory experiments were performed with a typical wood stove used for domestic heating in Portugal and operating under realistic home conditions. Aldehydes were sampled from diluted combustion flue gas using silica cartridges coated with 2,4-dinitrophenylhydrazine and analyzed by high performance liquid chromatography with diode array detection. The average formaldehyde to acetaldehyde concentration ratio (molar basis) in the stove flue gas was in the range of 2.1-2.9. Among the tested wood types, pyrenean oak produced the highest emissions for both formaldehyde and acetaldehyde: 1772 ± 649 and 1110 ± 454 mg kg-1 biomass burned (dry basis), respectively. By contrast, maritime pine produced the lowest emissions: 653 ± 151 and 371 ± 162 mg kg-1 biomass (dry basis) burned, respectively. Aldehydes were sampled separately during distinct periods of the holm oak wood combustion cycles. Significant variations in the flue gas concentrations were found, with higher values measured during the devolatilization stage than in the flaming and smoldering stages.

  15. On the Reaction Mechanism of Acetaldehyde Decomposition on Mo(110)

    SciTech Connect

    Mei, Donghai; Karim, Ayman M.; Wang, Yong

    2012-02-16

    The strong Mo-O bond strength provides promising reactivity of Mo-based catalysts for the deoxygenation of biomass-derived oxygenates. Combining the novel dimer saddle point searching method with periodic spin-polarized density functional theory calculations, we investigated the reaction pathways of a acetaldehyde decomposition on the clean Mo(110) surface. Two reaction pathways were identified, a selective deoxygenation and a nonselective fragmentation pathways. We found that acetaldehyde preferentially adsorbs at the pseudo 3-fold hollow site in the η2(C,O) configuration on Mo(110). Among four possible bond (β-C-H, γ-C-H, C-O and C-C) cleavages, the initial decomposition of the adsorbed acetaldehyde produces either ethylidene via the C-O bond scission or acetyl via the β-C-H bond scission while the C-C and the γ-C-H bond cleavages of acetaldehyde leading to the formation of methyl (and formyl) and formylmethyl are unlikely. Further dehydrogenations of ethylidene into either ethylidyne or vinyl are competing and very facile with low activation barriers of 0.24 and 0.31 eV, respectively. Concurrently, the formed acetyl would deoxygenate into ethylidyne via the C-O cleavage rather than breaking the C-C or the C-H bonds. The selective deoxygenation of acetaldehyde forming ethylene is inhibited by relatively weaker hydrogenation capability of the Mo(110) surface. Instead, the nonselective pathway via vinyl and vinylidene dehydrogenations to ethynyl as the final hydrocarbon fragment is kinetically favorable. On the other hand, the strong interaction between ethylene and the Mo(110) surface also leads to ethylene decomposition instead of desorption into the gas phase. This work was financially supported by the National Advanced Biofuels Consortium (NABC). Computing time was granted by a user project (emsl42292) at the Molecular Science Computing Facility in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). This work was financially supported

  16. The exchange of acetaldehyde between plants and the atmosphere: Stable carbon isotope and flux measurements

    NASA Astrophysics Data System (ADS)

    Jardine, Kolby Jeremiah

    The exchange of acetaldehyde between plant canopies and the atmosphere may significantly influence regional atmospheric chemistry and plant metabolism. While plants are known to both produce and consume acetaldehyde, the exchange of this compound with forested ecosystems is complicated by physical, biological, and chemical processes that range from being poorly understood to completely unknown. This precludes a quantitative understanding of acetaldehyde exchange rates between the atmosphere and the biosphere. In this study, the processes controlling the exchange of acetaldehyde with plant canopies was investigated using concentration, flux, and natural abundance 13C measurements of gas phase acetaldehyde from individual plants, soils, and entire ecosystems. Although previously only considered important in anoxic tissues, it was discovered that acetaldehyde is produced and consumed in leaves through ethanolic fermentation coupled to the pyruvate dehydrogenase bypass system under normal aerobic conditions. These coupled pathways determine the acetaldehyde compensation point, a major factor controlling its exchange with the atmosphere. Carbon isotope analysis suggests a new pathway for acetaldehyde production from plants under stress involving the peroxidation of membrane fatty acids. This pathway may be a major source of acetaldehyde to the atmosphere from plants under biotic and abiotic stresses. Plant stomata were found to be the dominant pathway for the exchange of acetaldehyde with the atmosphere with stomatal conductance influencing both emission and uptake fluxes. In addition, increasing temperature and solar radiation was found to increase the compensation point by increasing the rates of acetaldehyde production relative to consumption. Under ambient conditions, bare soil was neutral to the exchange of acetaldehyde while senescing and decaying leaves were found to be strong source of acetaldehyde to the atmosphere due to increased decomposition processes and

  17. Methanol Uptake by Low Temperature Aqueous Sulfuric Acid Solutions

    NASA Technical Reports Server (NTRS)

    Iraci, L. T.; Essin, A. M.; Golden, D. M.; Hipskind, R. Stephen (Technical Monitor)

    2001-01-01

    The global methanol budget is currently unbalanced, with source terms significantly larger than the sinks terms. To evaluate possible losses of gaseous methanol to sulfate aerosols, the solubility and reactivity of methanol in aqueous sulfuric acid solutions representative of upper tropospheric and lower stratospheric aerosols is under investigation. Methanol will partition into sulfate aerosols according to its Henry's law solubility. Using standard uptake techniques in a Knudsen cell reactor, we have measured the effective Henry's law coefficient, H*, for cold (196 - 220 K) solutions ranging between 45 and 70 wt % H2SO4. We have found that methanol solubility ranges from approx. 10(exp 5) - 10(exp 7) M/atm for UT/LS conditions. Solubility increases with decreasing temperature and with increasing sulfuric acid content. Although methanol is slightly more soluble than are acetone and formaldehyde, current data indicate that uptake by clean aqueous sulfuric acid particles will not be a significant sink for methanol in the UT/LS. These solubility measurements include uptake due to physical solvation and any rapid equilibria which are established in solution. Reaction between primary alcohols and sulfuric acid does occur, leading to the production of alkyl sulfates. Literature values for the rate of this reaction suggest that formation of CH3OSO3H is not significant over our experimental time scale for solutions below 80 wt % H2SO4. To confirm this directly, results obtained using a complementary equilibrium measurement technique will also be presented.

  18. Effect of acetaldehyde on Saccharomyces cerevisiae and Zymomonas mobilis subjected to environmental shocks

    SciTech Connect

    Stanley, G.A.; Hobley, T.J.; Pamment, N.B.

    1997-01-05

    The lag phase of Saccharomyces cerevisiae subjected to a step increase in temperature or ethanol concentration was reduced by as much as 60% when acetaldehyde was added to the medium at concentrations less than 0.1 g/L. Maximum specific growth rates were also substantially increased. Even greater proportional reductions in lag time due to acetaldehyde addition were observed for ethanol-shocked cultures of Zymomonas mobilis. Acetaldehyde had no effect on S. cerevisiae cultures started from stationary phase inocula in the absence of environmental shock and its lag-reducing effects were greater in complex medium than in a defined synthetic medium. Acetaldehyde reacted strongly with the ingredients of complex culture media. It is proposed that the effect of added acetaldehyde may be to compensate for the inability of cells to maintain transmembrane acetaldehyde gradients following an environmental shock.

  19. Adsorption and Reaction of Acetaldehyde over CeOx(111) Thin Films

    SciTech Connect

    T Chen; D Mullins

    2011-12-31

    This study reports the interaction of acetaldehyde with well-ordered CeO{sub X}(111) thin film surfaces. The fully oxidized CeO{sub 2}(111) surface shows a weak interaction with acetaldehyde with the sole desorption product (TPD) being the parent molecule at 210 K. The chemisorbed molecule binds to the surface as the {eta}{sub 1}-acetaldehyde species rather than through a bridge-bonded dioxy configuration. Acetaldehyde chemisorbs strongly on reduced CeO{sub 2-X}(111) with nonrecombinative and recombinative acetaldehyde desorbing at 405 and 550-600 K, respectively. Deoxygenation and dehydration also occur, producing ethylene and acetylene at 580 and 620 K, respectively. Acetaldehyde initially adsorbs in the {eta}{sub 1} configuration and then converts to a carbanion species with both C {double_bond} C and C {double_bond} O bond character above 300 K.

  20. Adsorption and Reaction of Acetaldehyde over CeO(X)(111) Thin Films

    SciTech Connect

    Chen, Tsung-Liang; Mahurin, Shannon Mark

    2011-01-01

    This study reports the interaction of acetaldehyde with well-ordered CeO{sub X}(111) thin film surfaces. The fully oxidized CeO{sub 2}(111) surface shows a weak interaction with acetaldehyde with the sole desorption product (TPD) being the parent molecule at 210 K. The chemisorbed molecule binds to the surface as the {eta}{sub 1}-acetaldehyde species rather than through a bridge-bonded dioxy configuration. Acetaldehyde chemisorbs strongly on reduced CeO{sub 2-X}(111) with nonrecombinative and recombinative acetaldehyde desorbing at 405 and 550-600 K, respectively. Deoxygenation and dehydration also occur, producing ethylene and acetylene at 580 and 620 K, respectively. Acetaldehyde initially adsorbs in the {eta}{sub 1} configuration and then converts to a carbanion species with both C=C and C=O bond character above 300 K.

  1. Divergent pathways of acetaldehyde and ethanol decarbonylation on the Rh(111) surface

    SciTech Connect

    Houtman, C.J.; Barteau, M.A. )

    1991-08-01

    The decomposition reactions of acetaldehyde and ethanol on the Rh(111) surface were compared in temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) experiments. The decarbonylation of acetaldehyde produced methane at 267 K in TPD. For acetaldehyde coverages less than 0.05 monolayer, no methane was desorbed, but for a coverage that saturated the first layer, methane was produced with 50% selectivity. Coadsorbing deuterium with a low coverage of acetaldehyde resulted in the enhancement of methane production. This result indicates that the selectivity to methane was partially controlled by the availability of hydrogen atoms on the surface required to hydrogenate the hydrocarbon species produced by acetaldehyde decarbonylation. Monodeuterated methane was the primary methane product observed after these coadsorption experiments. Thus it was concluded that acetaldehyde decarbonylates via a methyl migration mechanism on the Rh(111) surface. Decarbonylation of ethanol did not produce methane. The absence of methane production indicated that the decomposition of ethanol on the Rh(111) surface did not proceed via dehydrogenation to adsorbed acetaldehyde, but instead, ethanol appeared to dehydrogenate by methyl hydrogen abstraction resulting in the formation of an oxametallacycle. Since this proposed intermediate rapidly dehydrogenated to carbon monoxide and surface carbon, it was difficult to characterize spectroscopically. The existence of an ethanol decomposition pathway that does not include acetaldehyde intermediates indicates that ethanol formation on supported Rh catalysts may not be the result of acetaldehyde hydrogenation.

  2. Economic evaluation of the acetone - butanol fermentation

    SciTech Connect

    Lenz, T.G.; Morevra, A.R.

    1980-12-01

    The economics of producing acetone and 1-butanol via fermentation have been examined for a 45 X 10 to the power of 6 kg of solvents/year plant. For a molasses substrate, the total annual production costs were about $24.4 million vs. a total annual income of $36 million, with about $20 million total required capital. Molasses cost of about $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved about $11 million annually in feed costs and yielded about $7 million net additional annual revenues from protein sale. These primary differences gave an annual gross profit of about $15 million for the whey case and resulted in a discounted cash flow rate of return of 29%. It is concluded that waste based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  3. Acetone-butanol Fermentation of Marine Macroalgae

    SciTech Connect

    Huesemann, Michael H.; Kuo, Li-Jung; Urquhart, Lindsay A.; Gill, Gary A.; Roesijadi, Guritno

    2012-03-01

    Mannitol and laminarin, which are present at high concentrations in the brown macroalga Saccharina spp., a type of kelp, are potential biochemical feedstocks for butanol production. To test their bioconversion potential, aqueous extracts of the kelp Saccharina spp., mannitol, and glucose (a product of laminarin hydrolysis) were subjected to acetone-butanol fermentation by Clostridium acetobutylicum (ATCC 824). Both mannitol and glucose were readily fermented. Mixed substrate fermentations with glucose and mannitol resulted in diauxic growth of C. acetobutylicum with glucose depletion preceding mannitol utilization. Fermentation of kelp extract exhibited triauxic growth, with an order of utilization of free glucose, mannitol, and bound glucose, presumably laminarin. The lag in laminarin utilization reflected the need for enzymatic hydrolysis of this polysaccharide into fermentable sugars. The butanol and total solvent yields were 0.12 g/g and 0.16 g/g, respectively, indicating that significant improvements are still needed to make industrial-scale acetone-butanol fermentations of seaweed economically feasible.

  4. Enzymology of acetone-butanol-isopropanol formation

    SciTech Connect

    Chen, Jiann-Shin.

    1992-01-01

    The long-term goal of the project is to understand the fundamental properties of biological solvent production. Our approach is to elucidate first the molecular properties of solvent-producing enzymes and then to apply to information gained from the enzymological study to investigate control mechanisms for the solvent-producing pathways and the expression of solvent-production genes. Our research primarily involves two strains of Clostridium beijerinckii: C. Beijerinckii NRRL B593 which produces isopropanol in addition to acetone, butanol, and ethanol, and C. beijerinckii NRRL B592 which produces acetone, butanol and ethanol, but not isopropanol. In more recent studies, we also included another solvent-producing organism, Bacillus macerans. Objectives for the reporting period were: to characterize the distinct types of alcohol dehydrogenase; to purify and characterize acetoacetyl-CoA-reacting enzymes; and to clone and sequence the gene encoding the primary/secondary alcohol dehydrogenase of C beijerinckii NRRL B593 and to search for the promoter region for solvent-production genes.

  5. Excellent acetone sensing properties of porous ZnO

    NASA Astrophysics Data System (ADS)

    Liu, Chang-Bai; Liu, Xing-Yi; Wang, Sheng-Lei

    2015-01-01

    Porous ZnO was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous ZnO show that porous ZnO possesses excellent acetone gas sensing properties. The response is 35.5 at the optimum operating temperature of 320 °C to 100 ppm acetone. The response and recovery times to 50 ppm acetone are 2 s and 8 s, respectively. The lowest detecting limit to acetone is 0.25 ppm, and the response value is 3.8. Moreover, the sensors also exhibit excellent selectivity and long-time stability to acetone. Projected supported by the Project of Challenge Cup for College Students, China (Grant No. 450060497053).

  6. Acetone evaporation monitoring using a caterpillar-like microstructured fiber

    NASA Astrophysics Data System (ADS)

    Gomes, A. D.; Ferreira, M. F. S.; Moura, J. P.; André, R. M.; Silva, S. O.; Kobelke, J.; Bierlich, J.; Wondraczek, K.; Schuster, K.; Frazão, O.

    2015-09-01

    A new microstructured optical fiber is demonstrated to detect acetone evaporation by observing the time response of the reflected signal at 1550nm. The sensor consists on a caterpillar-like fiber, with a transversal microfluidic channel created with a Focused Ion Beam technique, spliced to a single-mode fiber. Different stages were visible between the dipping and the evaporation of acetone and of a mixture of water and acetone. It was also possible to detect the presence of water vapor.

  7. Apparatus and method for monitoring breath acetone and diabetic diagnostics

    DOEpatents

    Duan, Yixiang; Cao, Wenqing

    2008-08-26

    An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

  8. The Methanol Economy Project

    SciTech Connect

    Olah, George; Prakash, G. K.

    2014-02-01

    The Methanol Economy Project is based on the concept of replacing fossil fuels with methanol generated either from renewable resources or abundant natural (shale) gas. The full methanol cycle was investigated in this project, from production of methanol through bromination of methane, bireforming of methane to syngas, CO2 capture using supported amines, co-electrolysis of CO2 and water to formate and syngas, decomposition of formate to CO2 and H2, and use of formic acid in a direct formic acid fuel cell. Each of these projects achieved milestones and provided new insights into their respective fields.

  9. The detection of acetaldehyde in cold dust clouds

    NASA Technical Reports Server (NTRS)

    Matthews, H. E.; Friber, P.; Irvine, W. M.

    1985-01-01

    Observations of the 1(01)-0(00) rotational transitions of A and E state acetaldehyde are reported. The transitions were detected, for the first time in interstellar space, in the cold dust clouds TMC-1 and L134N, and in Sgr B2. This is also the first time acetaldehyde has been found in a dust cloud and is the most complex oxygen-bearing molecule yet known in this environment. A column density of 6 x 10 to the 12th/sq cm in TMC-1, comparable to many other species detected there, and an approximately equal column density in L134N are formed. In the direction of Sgr B2, the CH3CHO profile appears to consist of broad emission features from the hot molecular cloud core, together with absorption features resulting from intervening colder material. The possible detection of HC9N toward IRC + 10 deg 216 through its J = 33-32 transition is also reported. Implications for cold dust cloud chemistry and excitation are discussed.

  10. Roaming radical kinetics in the decomposition of acetaldehyde.

    SciTech Connect

    Harding, L. B.; Georgievskii, Y.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

    2010-01-01

    A novel theoretical framework for predicting the branching between roaming and bond fission channels in molecular dissociations is described and applied to the decomposition of acetaldehyde. This reduced dimensional trajectory (RDT) approach, which is motivated by the long-range nature of the roaming, bond fission, and abstraction dynamical bottlenecks, involves the propagation of rigid-body trajectories on an analytic potential energy surface. The analytic potential is obtained from fits to large-scale multireference ab initio electronic structure calculations. The final potential includes one-dimensional corrections from higher-level electronic structure calculations and for the effect of conserved mode variations along both the addition and abstraction paths. The corrections along the abstraction path play a significant role in the predicted branching. Master equation simulations are used to transform the microcanonical branching ratios obtained from the RDT simulations to the temperature- and pressure-dependent branching ratios observed in thermal decomposition experiments. For completeness, a transition-state theory treatment of the contributions of the tight transition states for the molecular channels is included in the theoretical analyses. The theoretically predicted branching between molecules and radicals in the thermal decomposition of acetaldehyde is in reasonable agreement with the corresponding shock tube measurement described in the companion paper. The prediction for the ratio of the tight to roaming contributions to the molecular channel also agrees well with results extracted from recent experimental and experimental/theoretical photodissociation studies.

  11. The detection of acetaldehyde in cold dust clouds.

    PubMed

    Matthews, H E; Friberg, P; Irvine, W M

    1985-03-15

    Observations of the 1(01) --> 0(00) rotational transitions of A and E state acetaldehyde are reported. The transitions were detected, for the first time in interstellar space, in the cold dust clouds TMC-1 and L134N, and in Sgr B2. This is also the first time acetaldehyde has been found in a dust cloud and is the most complex oxygen-bearing molecule yet known in this environment. We find a column density of 6 x 10(12) cm-2 in TMC-1, comparable to many other species detected there, and an approximately equal column density in L134N. In the direction of Sgr B2, the CH3CHO profile appears to consist of broad emission features from the hot molecular cloud core, together with absorption features resulting from intervening colder material. We also report the possible detection of HC9N toward IRC +10 degrees 216 through its J = 33 --> 32 transition. Implications for cold dust cloud chemistry and excitation are discussed.

  12. Dissociative electron attachment studies on acetone

    SciTech Connect

    Prabhudesai, Vaibhav S. Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

    2014-10-28

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H{sup −} is found to be the most dominant fragment followed by O{sup −} and OH{sup −} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup −} and O{sup −} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  13. Studies on the mechanism of acetaldehyde-mediated inhibition of rat liver transaminases.

    PubMed

    Solomon, L R

    1987-09-30

    Incubation of mitochondria-depleted rat liver homogenates with 5 mmol/l acetaldehyde at 37 degrees C for 1 h inhibited both aspartate and alanine aminotransferases by 30%. Inhibition was prevented by decreasing temperature to 4 degrees C or by preincubating homogenates with cyanate but was unaffected by cyanamide and methylpyrazole which block acetaldehyde oxidation and reduction respectively. Cyanate-sensitive acetaldehyde-mediated inhibition of purified porcine heart transaminases was also demonstrated in the presence of rat liver homogenate but not in Tris/sucrose medium. Moreover, porcine transaminases were inhibited by trichloroacetic acid extracts of rat liver homogenates previously incubated with acetaldehyde but not by extracts of homogenates incubated with both acetaldehyde and cyanate. These findings suggest that acetaldehyde-mediated transaminase inhibition requires further non-oxidative metabolism of acetaldehyde. Since transaminase activities were not restored by addition of pyridoxal 5'-phosphate to the assay systems, acetaldehyde-induced transaminase inhibition does not appear to be mediated by displacement or depletion of this B6 coenzyme. PMID:3677417

  14. The hydrogen-storing microporous silica 'Microcluster' reduces acetaldehyde contained in a distilled spirit.

    PubMed

    Kato, Shinya; Miwa, Nobuhiko

    2016-12-01

    Acetaldehyde is a detrimental substance produced in alcoholic liquor aging. We assessed an ability of hydrogen-storing microporous silica 'Microcluster' (MC+) to reduce acetaldehyde, as compared with autoclave-dehydrogenated MC+ (MC-). Acetaldehyde was quantified spectrophotometrically by an enzymatic method. Authentic acetaldehyde was treated by MC+ for 20min, and decreased from 43.4ppm to 10.9ppm, but maintained at 49.3ppm by MC-. On the other hand, acetaldehyde contained in a distilled spirit was decreased from 29.5ppm to 3.1ppm at 20min by MC+, but not decreased by MC-. Addition of MC+ or MC- to distilled water without acetaldehyde showed no seeming effect on the quantification used. Accordingly acetaldehyde in a distilled spirit is reduced to ethanol by hydrogen contained in MC+, but not by the silica moiety of MC+. Hydrogen gas of 1.2mL was released for 20min from MC+ of 0.59g in water, resulting in dissolved hydrogen of 1.09ppm and an oxidation- reduction potential of -687.0mV indicative of a marked reducing ability. Thus, MC+ has an ability to reduce acetaldehyde in a distilled spirit due to dissolved hydrogen released from MC+. PMID:27612695

  15. Removal of acetaldehyde and skatole in gas by a corona-discharge reactor

    SciTech Connect

    Sano, Noriaki; Nagamoto, Toshiki; Hamon, Hajime; Suzuki, Tetsuo; Okazaki, Morio

    1997-09-01

    Recently, ultrahigh gas purification has been important in many cases, such as, for example, (1) removal of dioxin from incineration plants, (2) complete removal of radioactive iodine compounds from nuclear fuel recycling, (3) simultaneous removal of NO{sub x} and SO{sub x} in exhaust gases from cogeneration plants, (4) removal or decomposition of chlorofluorocarbons, and (5) supply of purified gas for semiconductor industries. A corona-discharge reactor, called a deposition-type reactor, was applied to remove acetaldehyde and skatole from nitrogen and an oxygen-nitrogen mixture. In the removal from nitrogen, acetaldehyde and skatole are negatively ionized and removed by depositing at the anode surface. In simultaneous removals of acetaldehyde and skatole, it is found that skatole has a higher reactivity of electron attachment than acetaldehyde. In the removal of acetaldehyde from an oxygen-nitrogen mixture, 40 molecules of acetaldehyde were removed by one electron. The reason for the extremely high removal efficiency is considered to be based on the ozone reaction and the formation of negative-ion clusters. Stabilization energies of the negative-ion clusters were estimated by ab initio molecular orbital calculation. Skatole was removed from a nitrogen-oxygen mixture perfectly with extremely low discharge current by the ozone reaction. Simultaneous removals of acetaldehyde and skatole from a nitrogen-oxygen mixture suggest that coexisting skatole inhibits the removal of acetaldehyde.

  16. A PBPK MODEL FOR EVALUATING THE IMPACT OF ALDEHYDE DEHYDROGENASE POLYMORPHISMS ON COMPARATIVE RAT AND HUMAN NASAL TISSUE ACETALDEHYDE DOSIMETRY

    EPA Science Inventory

    ABSTRACT: Acetaldehyde is an important intermediate in chemical synthesis and a byproduct of normal oxidative metabolism of several industrially important compounds including ethanol, ethyl acetate and vinyl acetate. Chronic inhalation of acetaldehyde leads to degeneratio...

  17. A PBPK model for evaluating the impact of aldehyde dehydrogenase polymorphisms on comparative rat and human nasal tissue acetaldehyde dosimetry*

    EPA Science Inventory

    Acetaldehyde is an important intermediate in the chemical synthesis and normal oxidative metabolism of several industrially important compounds, including ethanol, ethyl acetate, and vinyl acetate. Chronic inhalation of acetaldehyde leads to degeneration of the olfactory and resp...

  18. DNA repair mutant pso2 of Saccharomyces cerevisiae is sensitive to intracellular acetaldehyde accumulated by disulfiram-mediated inhibition of acetaldehyde dehydrogenase.

    PubMed

    Brendel, M; Marisco, G; Ganda, I; Wolter, R; Pungartnik, C

    2010-01-12

    Blocking aldehyde dehydrogenase with the drug disulfiram leads to an accumulation of intracellular acetaldehyde, which negatively affects the viability of the yeast Saccharomyces cerevisiae. Mutants of the yeast gene PSO2, which encodes a protein specific for repair of DNA interstrand cross-links, showed higher sensitivity to disulfiram compared to the wild type. This leads us to suggest that accumulated acetaldehyde induces DNA lesions, including highly deleterious interstrand cross-links. Acetaldehyde induced the expression of a PSO2-lacZ reporter construct that is specifically inducible by bi- or poly-functional mutagens, e.g., nitrogen mustard and photo-activated psoralens. Chronic exposure of yeast cells to disulfiram and acute exposure to acetaldehyde induced forward mutagenesis in the yeast CAN1 gene. Disulfiram-induced mutability of a pso2Delta mutant was significantly increased over that of the isogenic wild type; however, this was not found for acetaldehyde-induced mutagenesis. Spontaneous mutability at the CAN1 locus was elevated in pso2Delta, suggesting that growth of glucose-repressed yeast produces DNA lesions that, in the absence of Pso2p-mediated crosslink repair, are partially removed by an error-prone DNA repair mechanism. The use of disulfiram in the control of human alcohol abuse increases cellular acetaldehyde pools, which, based on our observations, enhances the risk of mutagenesis and of other genetic damage.

  19. Dissociative electron attachments to ethanol and acetaldehyde: A combined experimental and simulation study

    NASA Astrophysics Data System (ADS)

    Wang, Xu-Dong; Xuan, Chuan-Jin; Feng, Wen-Ling; Tian, Shan Xi

    2015-02-01

    Dissociation dynamics of the temporary negative ions of ethanol and acetaldehyde formed by the low-energy electron attachments is investigated by using the anion velocity map imaging technique and ab initio molecular dynamics simulations. The momentum images of the dominant fragments O-/OH- and CH3- are recorded, indicating the low kinetic energies of O-/OH- for ethanol while the low and high kinetic energy distributions of O- ions for acetaldehyde. The CH3- image for acetaldehyde also shows the low kinetic energy. With help of the dynamics simulations, the fragmentation processes are qualitatively clarified. A new cascade dissociation pathway to produce the slow O- ion via the dehydrogenated intermediate, CH3CHO- (acetaldehyde anion), is proposed for the dissociative electron attachment to ethanol. After the electron attachment to acetaldehyde molecule, the slow CH3- is produced quickly in the two-body dissociation with the internal energy redistributions in different aspects before bond cleavages.

  20. Topical treatment of acne rosacea with benzoyl peroxide acetone gel.

    PubMed

    Montes, L F; Cordero, A A; Kriner, J; Loder, J; Flanagan, A D

    1983-08-01

    A group of patients with acne rosacea was treated with 5 percent benzoyl peroxide acetone gel for four weeks and then with 10 percent benzoyl peroxide acetone gel for an additional four weeks. A parallel group of patients was treated with a matching placebo (acetone gel vehicle). At the end of the first four weeks of treatment the dropout rate due to lack of improvement was 23 and 63 percent for benzoyl peroxide acetone gel and placebo, respectively. Benzoyl peroxide acetone gel was superior to placebo with respect to improvement in the overall severity of the lesions when judged by photographs, and by reduction of erythema, papules, and pustules. Results after treatment with benzoyl peroxide acetone gel were better during weeks five to eight than during weeks one to four for all lesions except telangiectasia. Benzoyl peroxide acetone gel was superior to placebo when the overall responses were compared. In addition, the benzoyl peroxide acetone gel-treated group, but not the placebo-treated group, showed a significantly better response during weeks five to eight compared to weeks one to four.

  1. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-17

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  2. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    1999-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  3. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    2001-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  4. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-24

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  5. [Effect of pyruvate, threonine, and phosphoethanolamine on acetaldehyde metabolism in rats with toxic liver injury].

    PubMed

    Pron'ko, P S; Satanovskaia, V I; Gorenshteĭn, B I; Kuz'mich, A B; Pyzhik, T N

    2002-01-01

    Pyruvate dehydrogenase, threonine aldolase and phosphoethanolamine lyase can produce acetaldehyde during normal metabolism. We studied the effect of loading with the substrates of these enzymes (pyruvate, 500 mg/kg, i.p., threonine 500 mg/kg, i.p., and phosphoethanolamine, 230 mg/kg, i.p.) on the blood concentrations of endogenous acetaldehyde and ethanol and the activities of enzymes producing and oxidizing acetaldehyde in the liver of normal rats and rats with liver injury provoked by chronic carbon tetrachloride (CCl4) treatment (0.2 ml i.p. per rat, 2 times a week during 4 weeks). Blood was collected before the treatment and then 30 min and 1 h following the administration of the substrates to intact and CCl4-treated rats. Endogenous acetaldehyde and ethanol were determined by headspace GC. The CCl4 treatment resulted in decreased liver alcohol dehydrogenase and aldehyde dehydrogenase activities and a significant elevation of liver endogenous ehtanol and a clear tendency to enhance blood acetaldehyde levels. Pyruvate increased blood endogenous acetaldehyde in CCl4-treated animals and endogenous ethanol--in the control group of animals. Threonine elevated endogenous acetaldehyde in normal rats. Phosphoethanolamine increased endogenous ethanol in the intact and CCl4 groups. At the same time, in CCl4-treated rats pyruvate administration increased the liver pyruvate dehydrogenase, threonine decreased threonine aldolase, whereas phosphoethanolamine decreased phosphoethanolamine lyase. Thus, the CCl4 effect on blood endogenous acetaldehyde and ethanol may be mediated through decreased liver ALDH and ADH activities. Liver injury promotes the accumulation of acetaldehyde, derived from physiological sources, including the degration of pyruvate and threonine by decreased acetaldehyde oxidation.

  6. Effect of Cobalt Particle Size on Acetone Steam Reforming

    SciTech Connect

    Sun, Junming; Zhang, He; Yu, Ning; Davidson, Stephen D.; Wang, Yong

    2015-06-11

    Carbon-supported cobalt nanoparticles with different particle sizes were synthesized and characterized by complementary characterization techniques such as X-ray diffraction, N-2 sorption, acetone temperature-programmed desorption, transmission electron microscopy, and CO chemisorption. Using acetone steam reforming reaction as a probe reaction, we revealed a volcano-shape curve of the intrinsic activity (turnover frequency of acetone) and the CO2 selectivity as a function of the cobalt particle size with the highest activity and selectivity observed at a particle size of approximately 12.8nm. Our results indicate that the overall performance of acetone steam reforming is related to a combination of particle-size-dependent acetone decomposition, water dissociation, and the oxidation state of the cobalt nanoparticles.

  7. Different role of filled and empty surface states in a polyfunctional molecule adsorption: Geranyl acetone on Si(111)7 x7

    NASA Astrophysics Data System (ADS)

    Carbone, M.; Comtet, G.; Dujardin, G.; Hellner, L.; Mayne, A. J.

    2002-09-01

    New perspectives in molecular electronics are opening up through controlled surface molecular synthesis. The first step of such a synthesis implies the adsorption of a polyfunctional molecule, which might use one functional group for the surface adsorption, and the other one(s) for further reactions. Here we present an adsorption study of Si(111)7 x7 of geranyl-acetone (C13H22O, E-5,9 undecadien-one) characterized by a ketone and two unconjugated double bonds. The study has been performed by temperature and coverage dependent valence band photoemission and room temperature scanning tunneling microscopy. The use of these combined techniques allows us to infer that the interaction between the geranyl acetone and the silicon surface occurs selectively through the rest atom and the carbonyl group, most likely through the oxygen atom. The geranyl acetone does not undergo any fragmentation upon adsorption Si(111)7 x7, as has been observed for smaller molecules on the same surface {acetaldehyde [Y. Bu, J. Breslin, M. C. Lin, J. Phys. Chem. B 101, 1872 (1997)] for instance}. The interaction of the chain with the surface is weak and is characterized in the STM images as a darkening of one adatom in positive bias, around the reacted rest atom.

  8. Resolving Some Paradoxes in the Thermal Decomposition Mechanism of Acetaldehyde.

    PubMed

    Sivaramakrishnan, Raghu; Michael, Joe V; Harding, Lawrence B; Klippenstein, Stephen J

    2015-07-16

    The mechanism for the thermal decomposition of acetaldehyde has been revisited with an analysis of literature kinetics experiments using theoretical kinetics. The present modeling study was motivated by recent observations, with very sensitive diagnostics, of some unexpected products in high temperature microtubular reactor experiments on the thermal decomposition of CH3CHO and its deuterated analogs, CH3CDO, CD3CHO, and CD3CDO. The observations of these products prompted the authors of these studies to suggest that the enol tautomer, CH2CHOH (vinyl alcohol), is a primary intermediate in the thermal decomposition of acetaldehyde. The present modeling efforts on acetaldehyde decomposition incorporate a master equation reanalysis of the CH3CHO potential energy surface (PES). The lowest-energy process on this PES is an isomerization of CH3CHO to CH2CHOH. However, the subsequent product channels for CH2CHOH are substantially higher in energy, and the only unimolecular process that can be thermally accessed is a reisomerization to CH3CHO. The incorporation of these new theoretical kinetics predictions into models for selected literature experiments on CH3CHO thermal decomposition confirms our earlier experiment and theory-based conclusions that the dominant decomposition process in CH3CHO at high temperatures is C-C bond fission with a minor contribution (∼10-20%) from the roaming mechanism to form CH4 and CO. The present modeling efforts also incorporate a master-equation analysis of the H + CH2CHOH potential energy surface. This bimolecular reaction is the primary mechanism for removal of CH2CHOH, which can accumulate to minor amounts at high temperatures, T > 1000 K, in most lab-scale experiments that use large initial concentrations of CH3CHO. Our modeling efforts indicate that the observation of ketene, water, and acetylene in the recent microtubular experiments are primarily due to bimolecular reactions of CH3CHO and CH2CHOH with H-atoms and have no bearing on

  9. Dietary methanol and autism.

    PubMed

    Walton, Ralph G; Monte, Woodrow C

    2015-10-01

    The authors sought to establish whether maternal dietary methanol during pregnancy was a factor in the etiology of autism spectrum disorders. A seven item questionnaire was given to women who had given birth to at least one child after 1984. The subjects were solicited from a large primary care practice and several internet sites and separated into two groups - mothers who had given birth to a child with autism and those who had not. Average weekly methanol consumption was calculated based on questionnaire responses. 550 questionnaires were completed by women who gave birth to a non-autistic child. On average these women consumed 66.71mg. of methanol weekly. 161 questionnaires were completed by women who had given birth to an autistic child. The average estimated weekly methanol consumption for this group was 142.31mg. Based on the results of the Wilcoxon rank sum-test, we see a significant difference between the reported methanol consumption rates of the two groups. This study suggests that women who have given birth to an autistic child are likely to have had higher intake of dietary sources of methanol than women who have not. Further investigation of a possible link of dietary methanol to autism is clearly warranted.

  10. Velocity-map imaging study of the photodissociation of acetaldehyde

    SciTech Connect

    Cruse, H.A.; Softley, T.P.

    2005-03-22

    Velocity-map imaging studies are reported for the photodissociation of acetaldehyde over a range of photolysis wavelengths (317.5-282.5 nm). Images are obtained for both the HCO and CH{sub 3} fragments. The mean rotational energy of both fragments increases with photodissociation energy, with a lesser degree of excitation in the CH{sub 3} fragment. The CH{sub 3} images demonstrate that the CH{sub 3} fragments are rotationally aligned with respect to the recoil direction and this is interpreted, and well modeled, on the basis of a propensity for forming CH{sub 3} fragments with M{approx}K, where M is the projection of the rotational angular momentum along the recoil direction. The origin of the CH{sub 3} rotation is conserved motion from the torsional and methyl-rocking modes of the parent molecule. Nonstatistical vibrational distributions for the CH{sub 3} fragment are obtained at higher energies.

  11. Pyrolysis of Acetaldehyde: a Fleeting Glimpse of Vinylidene

    NASA Astrophysics Data System (ADS)

    Vasilou, A. J.; Piech, K. M.; Ellison, G. B.; Golan, A.; Kostko, O.; Ahmed, M.; Osborn, D. L.; Daily, J. W.; Nimlos, M. R.; Stanton, J. F.

    2011-06-01

    The thermal decomposition of acetaldehyde has been studied in a heated silicon carbide ``microtubular reactor", with products monitored by both photoionization mass spectrometry and matrix-isolation Fourier transform infrared spectroscopy. A well-known, and observed, route of decomposition occurs when the weakest C-C bond is broken; this process leads to methyl and formyl radicals. In addition to this, we find evidence for two additional channels: CH_3CHO + Δ → H_2CCO (ketene) and CH_3CHO + Δ → C_2H_2 (acetylene), reactions that also generate molecular hydrogen and water, respectively. This talk focuses on the last pathway, which proceeds via vinyl alcohol. Evidence is presented that the high temperature unimolecular dehydration of vinyl alcohol proceeds by two mechanisms; one of these is a (1,2) elimination that directly yields acetylene, and the other is a (1,1) elimination that necessarily accesses the vinylidene isomer of C_2H_2 as an intermediate.

  12. Velocity-map imaging study of the photodissociation of acetaldehyde

    NASA Astrophysics Data System (ADS)

    Cruse, H. A.; Softley, T. P.

    2005-03-01

    Velocity-map imaging studies are reported for the photodissociation of acetaldehyde over a range of photolysis wavelengths (317.5-282.5 nm). Images are obtained for both the HCO and CH3 fragments. The mean rotational energy of both fragments increases with photodissociation energy, with a lesser degree of excitation in the CH3 fragment. The CH3 images demonstrate that the CH3 fragments are rotationally aligned with respect to the recoil direction and this is interpreted, and well modeled, on the basis of a propensity for forming CH3 fragments with M ˜K, where M is the projection of the rotational angular momentum along the recoil direction. The origin of the CH3 rotation is conserved motion from the torsional and methyl-rocking modes of the parent molecule. Nonstatistical vibrational distributions for the CH3 fragment are obtained at higher energies.

  13. Acetaldehyde involvement in ethanol's postabsortive effects during early ontogeny.

    PubMed

    March, Samanta M; Abate, P; Molina, Juan C

    2013-01-01

    Clinical and biomedical studies sustains the notion that early ontogeny is a vulnerable window to the impact of alcohol. Experiences with the drug during these stages increase latter disposition to prefer, use or abuse ethanol. This period of enhanced sensitivity to ethanol is accompanied by a high rate of activity in the central catalase system, which metabolizes ethanol in the brain. Acetaldehyde (ACD), the first oxidation product of ethanol, has been found to share many neurobehavioral effects with the drug. Cumulative evidence supports this notion in models employing adults. Nevertheless very few studies have been conducted to analyze the role of ACD in ethanol postabsorptive effects, in newborns or infant rats. In this work we review recent experimental literature that syndicates ACD as a mediator agent of reinforcing aspects of ethanol, during early ontogenetic stages. We also show a meta-analytical correlational approach that proposes how differences in the activity of brain catalase across ontogeny, could be modulating patterns of ethanol consumption.

  14. Computer modeling of cool flames and ignition of acetaldehyde

    SciTech Connect

    Cavanagh, J.; Cox, R.A. ); Olson, G. )

    1990-10-01

    A detailed mechanism for the oxidation of acetaldehyde at temperatures between 500-1000 K has been assembled using 77 elementary reactions involving 32 reactant, product, and intermediate species. Rate coefficients were taken from recent critical evaluations of experimental data. Where experimental measurements were not available, the rate parameters were estimated from the body of currently available kinetics information. The mechanism was shown to predict correctly the rates and products observed in CH{sub 3}CHO oxidation studies in a low-pressure in a stirred flow reactor and at high pressure in a rapid compression machine. The oscillatory phenomena in the flow system and the two-stage ignition observed at high pressure were satisfactorily described by the mechanism. It is shown that cool flames are caused by degenerate branching mainly by peracetic acid and that hydrogen peroxide promotes hot ignition.

  15. Acetone odor and irritation thresholds obtained from acetone-exposed factory workers and from control (occupationally unexposed) subjects.

    PubMed

    Wysocki, C J; Dalton, P; Brody, M J; Lawley, H J

    1997-10-01

    Sensitivity of olfaction (smell) and chemesthesis (irritation) was evaluated for 2-propanone (acetone) and 1-butanol in acetone-exposed workers (AEW; N = 32) during a workday and unexposed subjects (microES; N = 32). Irritation sensitivity was assessed using a method that relies on the ability of individuals to localize irritants on the body. When a volatile compound is inhaled into one nostril and air into the other, the stimulated side can be determined (lateralized) only after the concentration reaches a level that stimulates the trigeminal nerve (irritation); compounds stimulating olfaction alone cannot be lateralized. Intranasal lateralization thresholds offer an objective measure of sensory irritation elicited by volatile compounds. Test results indicated that neither olfactory nor lateralization thresholds for butanol differed between AEW and microES. Olfactory thresholds to acetone in AEW (855 ppm) were elevated relative to those of microES (41 ppm), as were lateralization thresholds (36,669 ppm and 15,758 ppm, respectively). Within AEW, level of occupational exposure was not correlated with thresholds. Other measures revealed that microES used more irritation descriptors than did AEW on trials where the acetone concentration was below the lateralization threshold. This is noteworthy because microES received lower concentrations of acetone to evaluate than did AEW. These results suggest that exposures to acetone induce changes in acetone sensitivity that are specific to acetone. The acetone concentrations eliciting sensory irritation using the lateralization technique were all well above current occupational exposure standards. The current study indicates that acetone is a weak sensory irritant and that sensory adaptation is an important factor affecting its overall irritancy. PMID:9342830

  16. An ethanolamine plasmalogen artifact formed by acetone extraction of freeze-dried tissue.

    PubMed

    Helmy, F M; Hack, M H

    1966-07-01

    Extraction of freeze-dried tissues by acetone results in the in vitro production of an acetone derivative (imine) of the ethanolamine phosphatides. Some of the properties of the acetone imine of ethanolamine plasmalogen are discussed.

  17. Role of apoptotic hepatocytes in HCV dissemination: regulation by acetaldehyde.

    PubMed

    Ganesan, Murali; Natarajan, Sathish Kumar; Zhang, Jinjin; Mott, Justin L; Poluektova, Larisa I; McVicker, Benita L; Kharbanda, Kusum K; Tuma, Dean J; Osna, Natalia A

    2016-06-01

    Alcohol consumption exacerbates hepatitis C virus (HCV) pathogenesis and promotes disease progression, although the mechanisms are not quite clear. We have previously observed that acetaldehyde (Ach) continuously produced by the acetaldehyde-generating system (AGS), temporarily enhanced HCV RNA levels, followed by a decrease to normal or lower levels, which corresponded to apoptosis induction. Here, we studied whether Ach-induced apoptosis caused depletion of HCV-infected cells and what role apoptotic bodies (AB) play in HCV-alcohol crosstalk. In liver cells exposed to AGS, we observed the induction of miR-122 and miR-34a. As miR-34a has been associated with apoptotic signaling and miR-122 with HCV replication, these findings may suggest that cells with intensive viral replication undergo apoptosis. Furthermore, when AGS-induced apoptosis was blocked by a pan-caspase inhibitor, the expression of HCV RNA was not changed. AB from HCV-infected cells contained HCV core protein and the assembled HCV particle that infect intact hepatocytes, thereby promoting the spread of infection. In addition, AB are captured by macrophages to switch their cytokine profile to the proinflammatory one. Macrophages exposed to HCV(+) AB expressed more IL-1β, IL-18, IL-6, and IL-10 mRNAs compared with those exposed to HCV(-) AB. The generation of AB from AGS-treated HCV-infected cells even enhanced the induction of aforementioned cytokines. We conclude that HCV and alcohol metabolites trigger the formation of AB containing HCV particles. The consequent spread of HCV to neighboring hepatocytes via infected AB, as well as the induction of liver inflammation by AB-mediated macrophage activation potentially exacerbate the HCV infection course by alcohol and worsen disease progression. PMID:27056722

  18. Measuring breath acetone for monitoring fat loss: Review

    PubMed Central

    2015-01-01

    Objective Endogenous acetone production is a by‐product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. Results BrAce can range from 1 ppm in healthy non‐dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. Conclusions When biologic factors are controlled, BrAce measurement provides a non‐invasive tool for monitoring the rate of fat loss in healthy subjects. PMID:26524104

  19. Acetone cluster ion beam irradiation on solid surfaces

    NASA Astrophysics Data System (ADS)

    Ryuto, H.; Kakumoto, Y.; Itozaki, S.; Takeuchi, M.; Takaoka, G. H.

    2013-11-01

    Acetone cluster ions were produced by the adiabatic expansion method without using a support gas. The acceleration voltage of the acetone cluster ion beam was from 3 to 9 kV. The sputter depths of silicon irradiated with acetone cluster ion beams increased with acceleration voltage and fluence of the acetone cluster ion beams. The sputter depth was close to that induced by the ethanol cluster ion beam accelerated at the same acceleration voltage. The sputtering yield of silicon by the acetone cluster ion beam at an acceleration voltage of 9 kV was approximately 100 times larger than that for an argon monomer ion beam at 9 keV. The sputter depths of silicon dioxide irradiated with the acetone cluster ion beams were smaller than those of silicon, but larger than those induced by ethanol cluster ion beams. The XPS analysis of silicon surface indicated that the silicon surface was more strongly oxidized by the irradiation of acetone cluster ion beam than ethanol cluster ion beam.

  20. Susceptibility to inhalation toxicity of acetaldehyde in Aldh2 knockout mice.

    PubMed

    Oyama, Tsunehiro; Isse, Toyohi; Ogawa, Masanori; Muto, Manabu; Uchiyama, Iwao; Kawamoto, Toshihiro

    2007-01-01

    In this study, we evaluated the inhalation toxicity of acetaldehyde in Aldh2 KO (Aldh -/-) mice, using pathological method. Male C57BL/6 (Aldh2 +/+) mice and Aldh -/- mice were exposed to atmospheres containing acetaldehyde at levels of 0, 125, and 500 ppm for 24 h/day during 14 days. Although the average blood acetaldehyde concentration of Aldh -/- mice was higher than that of Aldh2 +/+ mice in the acetaldehyde exposure group, observable effects by the acetaldehyde exposure on the lung and liver were not different between wild type and ALDH2 null mice. In Aldh2 -/- mice, the levels of 1) erosion of respiratory epithelium and the subepithelial hemorrhage in nose, 2) hemorrhage in nasal cavity, 3) degeneration of respiratory epithelium in larynx, pharynx and trachea, and 4) degeneration of dorsal skin were higher compared with Aldh2 +/+ mice, indicating that Aldh2 -/- mice are more acetaldehyde-sensitive than Aldh2 +/+ mice. This is the first example for studying pathological effects of Aldh2 deficiency using Aldh -/- mice exposed to a low level of acetaldehyde. PMID:17127431

  1. The effects of acetaldehyde and acrolein on muscle catabolism in C2 myotubes.

    PubMed

    Rom, Oren; Kaisari, Sharon; Aizenbud, Dror; Reznick, Abraham Z

    2013-12-01

    The toxic aldehydes acetaldehyde and acrolein were previously suggested to damage skeletal muscle. Several conditions in which exposure to acetaldehyde and acrolein is increased were associated with muscle wasting and dysfunction. These include alcoholic myopathy, renal failure, oxidative stress, and inflammation. A main exogenous source of both acetaldehyde and acrolein is cigarette smoking, which was previously associated with increased muscle catabolism. Recently, we have shown that exposure of skeletal myotubes to cigarette smoke stimulated muscle catabolism via increased oxidative stress, activation of p38 MAPK, and upregulation of muscle-specific E3 ubiquitin ligases. In this study, we aimed to investigate the effects of acetaldehyde and acrolein on catabolism of skeletal muscle. Skeletal myotubes differentiated from the C2 myoblast cell line were exposed to acetaldehyde or acrolein and their effects on signaling pathways related to muscle catabolism were studied. Exposure of myotubes to acetaldehyde did not promote muscle catabolism. However, exposure to acrolein caused increased generation of free radicals, activation of p38 MAPK, upregulation of the muscle-specific E3 ligases atrogin-1 and MuRF1, degradation of myosin heavy chain, and atrophy of myotubes. Inhibition of p38 MAPK by SB203580 abolished acrolein-induced muscle catabolism. Our findings demonstrate that acrolein but not acetaldehyde activates a signaling cascade resulting in muscle catabolism in skeletal myotubes. Although within the limitations of an in vitro study, these findings indicate that acrolein may promote muscle wasting in conditions of increased exposure to this aldehyde.

  2. Determination of breath acetone in 149 type 2 diabetic patients using a ringdown breath-acetone analyzer.

    PubMed

    Sun, Meixiu; Chen, Zhuying; Gong, Zhiyong; Zhao, Xiaomeng; Jiang, Chenyu; Yuan, Yuan; Wang, Zhennang; Li, Yingxin; Wang, Chuji

    2015-02-01

    Over 90% of diabetic patients have Type 2 diabetes. Although an elevated mean breath acetone concentration has been found to exist in Type 1 diabetes (T1D), information on breath acetone in Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous blood glucose levels were also measured using a standard diabetic-management blood-glucose meter. For the 149 T2D subjects, their exhaled breath acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of

  3. ALDH2 modulates autophagy flux to regulate acetaldehyde-mediated toxicity thresholds.

    PubMed

    Tanaka, Koji; Whelan, Kelly A; Chandramouleeswaran, Prasanna M; Kagawa, Shingo; Rustgi, Sabrina L; Noguchi, Chiaki; Guha, Manti; Srinivasan, Satish; Amanuma, Yusuke; Ohashi, Shinya; Muto, Manabu; Klein-Szanto, Andres J; Noguchi, Eishi; Avadhani, Narayan G; Nakagawa, Hiroshi

    2016-01-01

    A polymorphic mutation in the acetaldehyde dehydrogenase 2 (ALDH2) gene has been epidemiologically linked to the high susceptibility to esophageal carcinogenesis for individuals with alcohol use disorders. Mice subjected to alcohol drinking show increased oxidative stress and DNA adduct formation in esophageal epithelia where Aldh2 loss augments alcohol-induced genotoxic effects; however, it remains elusive as to how esophageal epithelial cells with dysfunctional Aldh2 cope with oxidative stress related to alcohol metabolism. Here, we investigated the role of autophagy in murine esophageal epithelial cells (keratinocytes) exposed to ethanol and acetaldehyde. We find that ethanol and acetaldehyde trigger oxidative stress via mitochondrial superoxide in esophageal keratinocytes. Aldh2-deficient cells appeared to be highly susceptible to ethanol- or acetaldehyde-mediated toxicity. Alcohol dehydrogenase-mediated acetaldehyde production was implicated in ethanol-induced cell injury in Aldh2 deficient cells as ethanol-induced oxidative stress and cell death was partially inhibited by 4-methylpyrazole. Acetaldehyde activated autophagy flux in esophageal keratinocytes where Aldh2 deficiency increased dependence on autophagy to cope with ethanol-induced acetaldehyde-mediated oxidative stress. Pharmacological inhibition of autophagy flux by chloroquine stabilized p62/SQSTM1, and increased basal and acetaldehyde-mediate oxidative stress in Aldh2 deficient cells as documented in monolayer culture as well as single-cell derived three-dimensional esophageal organoids, recapitulating a physiological esophageal epithelial proliferation-differentiation gradient. Our innovative approach indicates, for the first time, that autophagy may provide cytoprotection to esophageal epithelial cells responding to oxidative stress that is induced by ethanol and its major metabolite acetaldehyde. Defining autophagymediated cytoprotection against alcohol-induced genotoxicity in the context of

  4. ALDH2 modulates autophagy flux to regulate acetaldehyde-mediated toxicity thresholds

    PubMed Central

    Tanaka, Koji; Whelan, Kelly A; Chandramouleeswaran, Prasanna M; Kagawa, Shingo; Rustgi, Sabrina L; Noguchi, Chiaki; Guha, Manti; Srinivasan, Satish; Amanuma, Yusuke; Ohashi, Shinya; Muto, Manabu; Klein-Szanto, Andres J; Noguchi, Eishi; Avadhani, Narayan G; Nakagawa, Hiroshi

    2016-01-01

    A polymorphic mutation in the acetaldehyde dehydrogenase 2 (ALDH2) gene has been epidemiologically linked to the high susceptibility to esophageal carcinogenesis for individuals with alcohol use disorders. Mice subjected to alcohol drinking show increased oxidative stress and DNA adduct formation in esophageal epithelia where Aldh2 loss augments alcohol-induced genotoxic effects; however, it remains elusive as to how esophageal epithelial cells with dysfunctional Aldh2 cope with oxidative stress related to alcohol metabolism. Here, we investigated the role of autophagy in murine esophageal epithelial cells (keratinocytes) exposed to ethanol and acetaldehyde. We find that ethanol and acetaldehyde trigger oxidative stress via mitochondrial superoxide in esophageal keratinocytes. Aldh2-deficient cells appeared to be highly susceptible to ethanol- or acetaldehyde-mediated toxicity. Alcohol dehydrogenase-mediated acetaldehyde production was implicated in ethanol-induced cell injury in Aldh2 deficient cells as ethanol-induced oxidative stress and cell death was partially inhibited by 4-methylpyrazole. Acetaldehyde activated autophagy flux in esophageal keratinocytes where Aldh2 deficiency increased dependence on autophagy to cope with ethanol-induced acetaldehyde-mediated oxidative stress. Pharmacological inhibition of autophagy flux by chloroquine stabilized p62/SQSTM1, and increased basal and acetaldehyde-mediate oxidative stress in Aldh2 deficient cells as documented in monolayer culture as well as single-cell derived three-dimensional esophageal organoids, recapitulating a physiological esophageal epithelial proliferation-differentiation gradient. Our innovative approach indicates, for the first time, that autophagy may provide cytoprotection to esophageal epithelial cells responding to oxidative stress that is induced by ethanol and its major metabolite acetaldehyde. Defining autophagymediated cytoprotection against alcohol-induced genotoxicity in the context of

  5. Methanol Cannon Demonstrations Revisited.

    ERIC Educational Resources Information Center

    Dolson, David A.; And Others

    1995-01-01

    Describes two variations on the traditional methanol cannon demonstration. The first variation is a chain reaction using real metal chains. The second example involves using easily available components to produce sequential explosions that can be musical in nature. (AIM)

  6. The Methanol Multibeam Survey

    NASA Astrophysics Data System (ADS)

    Green, James A.; Cohen, R. J.; Caswell, J. L.; Fuller, G. A.; Brooks, K.; Burton, M. G.; Chrysostomou, A.; Diamond, P. J.; Ellingsen, S. P.; Gray, M. D.; Hoare, M. G.; Masheder, M. R. W.; McClure-Griffiths, N.; Pestalozzi, M.; Phillips, C.; Quinn, L.; Thompson, M. A.; Voronkov, M.; Walsh, A.; Ward-Thompson, D.; Wong-McSweeney, D.; Yates, J. A.; Cox, J.

    2007-03-01

    A new 7-beam methanol multibeam receiver is being used to survey the Galaxy for newly forming massive stars, that are pinpointed by strong methanol maser emission at 6.668 GHz. The receiver, jointly constructed by Jodrell Bank Observatory (JBO) and the Australia Telescope National Facility (ATNF), was successfully commissioned at Parkes in January 2006. The Parkes-Jodrell survey of the Milky Way for methanol masers is two orders of magnitude faster than previous systematic surveys using 30-m class dishes, and is the first systematic survey of the entire Galactic plane. The first 53 days of observations with the Parkes telescope have yielded 518 methanol sources, of which 218 are new discoveries. We present the survey methodology as well as preliminary results and analysis.

  7. Inhibition of acetaminophen activation by ethanol and acetaldehyde in liver microsomes

    SciTech Connect

    Chifumi Sato; Jian Liu; Happei Miyakawa; Toshihiko Nouchi; Yujiro Tanaka; Masakatsu Uchihara; Fumiaki Marumo Tokyo Medical and Dental Univ. )

    1991-01-01

    Mechanisms of the inhibitory effect of ethanol on acetaminophen hepatotoxicity are controversial. The authors studied the effects of ethanol and acetaldehyde, and oxidative metabolite of ethanol, on NADHP-dependent acetaminophen-glutathione conjugate production in liver microsomes. Ethanol at concentrations as low as 2mM prevented the conjugate production noncompetitively. Acetaldehyde also inhibited acetaminophen-glutathione conjugate production at concentrations as low as 0.1 mM that is comparable with those observed in vivo after social drinking. Acetaldehyde may be involved in ethanol-induced inhibition of acetaminophen hepatotoxicity.

  8. Acetaldehyde stimulation of net gluconeogenic carbon movement from applied malic acid in tomato fruit pericarp tissue

    SciTech Connect

    Halinska, A.; Frenkel, C. )

    1991-03-01

    Applied acetaldehyde is known to lead to sugar accumulation in fruit including tomatoes (Lycopersicon esculentum) presumably due to stimulation of gluconeogenesis. This conjecture was examined using tomato fruit pericarp discs as a test system and applied l-(U-{sup 14}C)malic acid as the source for gluconeogenic carbon mobilization. Results indicate that malic and perhaps other organic acids are carbon sources for gluconeogenesis occurring normally in ripening tomatoes. The process is stimulated by acetaldehyde apparently by attenuating the fructose-2,6-biphosphate levels. The mode of the acetaldehyde regulation of fructose-2,6-biphosphate metabolism awaits clarification.

  9. C1 Metabolism in Corynebacterium glutamicum: an Endogenous Pathway for Oxidation of Methanol to Carbon Dioxide

    PubMed Central

    Witthoff, Sabrina; Mühlroth, Alice

    2013-01-01

    Methanol is considered an interesting carbon source in “bio-based” microbial production processes. Since Corynebacterium glutamicum is an important host in industrial biotechnology, in particular for amino acid production, we performed studies of the response of this organism to methanol. The C. glutamicum wild type was able to convert 13C-labeled methanol to 13CO2. Analysis of global gene expression in the presence of methanol revealed several genes of ethanol catabolism to be upregulated, indicating that some of the corresponding enzymes are involved in methanol oxidation. Indeed, a mutant lacking the alcohol dehydrogenase gene adhA showed a 62% reduced methanol consumption rate, indicating that AdhA is mainly responsible for methanol oxidation to formaldehyde. Further studies revealed that oxidation of formaldehyde to formate is catalyzed predominantly by two enzymes, the acetaldehyde dehydrogenase Ald and the mycothiol-dependent formaldehyde dehydrogenase AdhE. The Δald ΔadhE and Δald ΔmshC deletion mutants were severely impaired in their ability to oxidize formaldehyde, but residual methanol oxidation to CO2 was still possible. The oxidation of formate to CO2 is catalyzed by the formate dehydrogenase FdhF, recently identified by us. Similar to the case with ethanol, methanol catabolism is subject to carbon catabolite repression in the presence of glucose and is dependent on the transcriptional regulator RamA, which was previously shown to be essential for expression of adhA and ald. In conclusion, we were able to show that C. glutamicum possesses an endogenous pathway for methanol oxidation to CO2 and to identify the enzymes and a transcriptional regulator involved in this pathway. PMID:24014532

  10. C1 metabolism in Corynebacterium glutamicum: an endogenous pathway for oxidation of methanol to carbon dioxide.

    PubMed

    Witthoff, Sabrina; Mühlroth, Alice; Marienhagen, Jan; Bott, Michael

    2013-11-01

    Methanol is considered an interesting carbon source in "bio-based" microbial production processes. Since Corynebacterium glutamicum is an important host in industrial biotechnology, in particular for amino acid production, we performed studies of the response of this organism to methanol. The C. glutamicum wild type was able to convert (13)C-labeled methanol to (13)CO2. Analysis of global gene expression in the presence of methanol revealed several genes of ethanol catabolism to be upregulated, indicating that some of the corresponding enzymes are involved in methanol oxidation. Indeed, a mutant lacking the alcohol dehydrogenase gene adhA showed a 62% reduced methanol consumption rate, indicating that AdhA is mainly responsible for methanol oxidation to formaldehyde. Further studies revealed that oxidation of formaldehyde to formate is catalyzed predominantly by two enzymes, the acetaldehyde dehydrogenase Ald and the mycothiol-dependent formaldehyde dehydrogenase AdhE. The Δald ΔadhE and Δald ΔmshC deletion mutants were severely impaired in their ability to oxidize formaldehyde, but residual methanol oxidation to CO2 was still possible. The oxidation of formate to CO2 is catalyzed by the formate dehydrogenase FdhF, recently identified by us. Similar to the case with ethanol, methanol catabolism is subject to carbon catabolite repression in the presence of glucose and is dependent on the transcriptional regulator RamA, which was previously shown to be essential for expression of adhA and ald. In conclusion, we were able to show that C. glutamicum possesses an endogenous pathway for methanol oxidation to CO2 and to identify the enzymes and a transcriptional regulator involved in this pathway.

  11. Toward portable breath acetone analysis for diabetes detection.

    PubMed

    Righettoni, Marco; Tricoli, Antonio

    2011-09-01

    Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO(3) nanoparticles, made by flame spray pyrolysis, as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostics. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber is discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

  12. Toward Portable Breath Acetone Analysis for Diabetes Detection

    PubMed Central

    Righettoni, Marco; Tricoli, Antonio

    2013-01-01

    Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO3 nanoparticles made by flame spray pyrolysis as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostic. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber are discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

  13. Characterisation of cellulose films regenerated from acetone/water coagulants.

    PubMed

    Geng, Hongjuan; Yuan, Zaiwu; Fan, Qingrui; Dai, Xiaonan; Zhao, Yue; Wang, Zhaojiang; Qin, Menghua

    2014-02-15

    A precooled aqueous solution of 7 wt% NaOH/12 wt% urea was used to dissolve cellulose up to a concentration of 2 wt%, which was then coagulated in an acetone/water mixture to regenerate cellulose film. The volume ratio of acetone to water (φ) had a dominant influence on film dimensional stability, film-forming ability, micromorphology, and mechanical strength. The film regenerated at φ=2.0 showed excellent performance in both dimensional stability and film-forming ability. Compared to that from pure acetone, the cellulose film from the acetone/water mixture with φ=2.0 was more densely interwoven, since the cellulosic fibrils formed during regeneration had pores with smaller average diameter. The alkali capsulated in the film during film formation could be released at quite a slow rate into the surrounding aqueous solution. The regenerated cellulose film with adjustable structure and properties may have potential applications in drug release and ultra filtration.

  14. Acetone sensor based on zinc oxide hexagonal tubes

    SciTech Connect

    Hastir, Anita Singh, Onkar Anand, Kanika Singh, Ravi Chand

    2014-04-24

    In this work hexagonal tubes of zinc oxide have been synthesized by co-precipitation method. For structural, morphological, elemental and optical analysis synthesized powders were characterized by using x-ray diffraction, field emission scanning microscope, EDX, UV-visible and FTIR techniques. For acetone sensing thick films of zinc oxide have been deposited on alumina substrate. The fabricated sensors exhibited maximum sensing response towards acetone vapour at an optimum operating temperature of 400°C.

  15. Acetaldehyde Adsorption and Reaction onCeO2(100) Thin Films

    SciTech Connect

    Mullins, David R; Albrecht, Peter M

    2013-01-01

    This study reports and compares the adsorption and dissociation of acetaldehyde on oxidized and reduced CeOX(100) thin films. Acetaldehyde reacts and decomposes on fully oxidized CeO2(100) whereas it desorbs molecularly at low temperature on CeO2(111). The primary products are CO, CO2 and water along with trace amounts of crotonaldehyde and acetylene. The acetaldehyde adsorbs as the 2-acetaldehyde species, dioxyethylene. Decomposition proceeds by dehydrogenation through acetate and enolate intermediates. The reaction pathway is similar on the reduced CeO2-X(100) surface however the inability to react with surface O on the reduced surface results in H2 rather than H2O desorption and C is left on the surface rather than producing CO and CO2. C-O bond cleavage in the enolate intermediate followed by reaction with surface H results in ethylene desorption.

  16. Rosiglitazone protects human neuroblastoma SH-SY5Y cells against acetaldehyde-induced cytotoxicity

    SciTech Connect

    Jung, Tae Woo; Lee, Ji Young; Shim, Wan Sub; Kang, Eun Seok; Kim, Soo Kyung; Ahn, Chul Woo; Lee, Hyun Chul; Cha, Bong Soo . E-mail: bscha@yumc.yonsei.ac.kr

    2006-02-03

    Acetaldehyde, an inhibitor of mitochondrial function, has been widely used as a neurotoxin because it elicits a severe Parkinson's disease-like syndrome with elevation of the intracellular reactive oxygen species level and apoptosis. Rosiglitazone, a peroxisome proliferator-activated receptor-{gamma} agonist, has been known to show various non-hypoglycemic effects, including anti-inflammatory, anti-atherogenic, and anti-apoptotic. In this study, we investigated the protective effects of rosiglitazone on acetaldehyde-induced apoptosis in human neuroblastoma SH-SY5Y cells and attempted to examine its mechanism. Acetaldehyde-induced apoptosis was moderately reversed by rosiglitazone treatment. Our results suggest that the protective effects of rosiglitazone on acetaldehyde-induced apoptosis may be ascribed to ability to induce the expression of anti-oxidant enzymes and to regulate Bcl-2 and Bax expression. These data indicate that rosiglitazone may provide a useful therapeutic strategy for the prevention of progressive neurodegenerative disease such as Parkinson's disease.

  17. Maximizing recovery of water-soluble proteins through acetone precipitation.

    PubMed

    Crowell, Andrew M J; Wall, Mark J; Doucette, Alan A

    2013-09-24

    Solvent precipitation is commonly used to purify protein samples, as seen with the removal of sodium dodecyl sulfate through acetone precipitation. However, in its current practice, protein loss is believed to be an inevitable consequence of acetone precipitation. We herein provide an in depth characterization of protein recovery through acetone precipitation. In 80% acetone, the precipitation efficiency for six of 10 protein standards was poor (ca. ≤15%). Poor recovery was also observed for proteome extracts, including bacterial and mammalian cells. As shown in this work, increasing the ionic strength of the solution dramatically improves the precipitation efficiency of individual proteins, and proteome mixtures (ca. 80-100% yield). This is obtained by including 1-30 mM NaCl, together with acetone (50-80%) which maximizes protein precipitation efficiency. The amount of salt required to restore the recovery correlates with the amount of protein in the sample, as well as the intrinsic protein charge, and the dielectric strength of the solution. This synergistic approach to protein precipitation in acetone with salt is consistent with a model of ion pairing in organic solvent, and establishes an improved method to recover proteins and proteome mixtures in high yield.

  18. Coproduction of Acetaldehyde and Hydrogen during Glucose Fermentation by Escherichia coli ▿ †

    PubMed Central

    Zhu, Huilin; Gonzalez, Ramon; Bobik, Thomas A.

    2011-01-01

    Escherichia coli K-12 strain MG1655 was engineered to coproduce acetaldehyde and hydrogen during glucose fermentation by the use of exogenous acetyl-coenzyme A (acetyl-CoA) reductase (for the conversion of acetyl-CoA to acetaldehyde) and the native formate hydrogen lyase. A putative acetaldehyde dehydrogenase/acetyl-CoA reductase from Salmonella enterica (SeEutE) was cloned, produced at high levels, and purified by nickel affinity chromatography. In vitro assays showed that this enzyme had both acetaldehyde dehydrogenase activity (68.07 ± 1.63 μmol min−1 mg−1) and the desired acetyl-CoA reductase activity (49.23 ± 2.88 μmol min−1 mg−1). The eutE gene was engineered into an E. coli mutant lacking native glucose fermentation pathways (ΔadhE, ΔackA-pta, ΔldhA, and ΔfrdC). The engineered strain (ZH88) produced 4.91 ± 0.29 mM acetaldehyde while consuming 11.05 mM glucose but also produced 6.44 ± 0.26 mM ethanol. Studies showed that ethanol was produced by an unknown alcohol dehydrogenase(s) that converted the acetaldehyde produced by SeEutE to ethanol. Allyl alcohol was used to select for mutants with reduced alcohol dehydrogenase activity. Three allyl alcohol-resistant mutants were isolated; all produced more acetaldehyde and less ethanol than ZH88. It was also found that modifying the growth medium by adding 1 g of yeast extract/liter and lowering the pH to 6.0 further increased the coproduction of acetaldehyde and hydrogen. Under optimal conditions, strain ZH136 converted glucose to acetaldehyde and hydrogen in a 1:1 ratio with a specific acetaldehyde production rate of 0.68 ± 0.20 g h−1 g−1 dry cell weight and at 86% of the maximum theoretical yield. This specific production rate is the highest reported thus far and is promising for industrial application. The possibility of a more efficient “no-distill” ethanol fermentation procedure based on the coproduction of acetaldehyde and hydrogen is discussed. PMID:21803884

  19. Acetaldehyde: A Small Organic Molecule with Big Impact on Organocatalytic Reactions.

    PubMed

    Kim, Sun Min; Kim, Young Sug; Kim, Dong Wan; Rios, Ramon; Yang, Jung Woon

    2016-02-12

    Stereocontrolled formation of carbon-carbon and carbon-heteroatom bonds through asymmetric organocatalysis is a formidable challenge for modern synthetic chemistry. Among the most significant contributions to this field are the transformations involving the use of acetaldehyde or α-heteroatom-substituted acetaldehydes for constructing valuable synthons (e.g., amino acid derivatives and hydroxycarbonyl). In this Minireview, versatile (enantioselective) organocatalytic transformations are discussed.

  20. Effects of acetaldehyde on hepatocyte glycerol uptake and cell size: implication of Aquaporin 9

    PubMed Central

    Potter, James J.; Koteish, Ayman; Hamilton, James; Liu, Xiaopu; Liu, Kun; Agre, Peter; Mezey, Esteban

    2010-01-01

    Background The effects of ethanol and acetaldehyde on uptake of glycerol and on cell size of hepatocytes and a role Aquaporin 9 (AQP9), a glycerol transport channel, were evaluated. Methods The studies were done in primary rat and mouse hepatocytes. The uptake of [14C] glycerol was determined with hepatocytes in suspension. For determination of cell size, rat hepatocytes on coated dishes were incubated with a lipophilic fluorochrome that is incorporated into the cell membrane and examined by confocal microscopy. A three dimensional z scan of the cell was performed, and the middle slice of the z scan was used for area measurements. Results Acute exposure to acetaldehyde, but not to ethanol, causes a rapid increase in the uptake of glycerol and an increase in hepatocyte size, which was inhibited by HgCl2, an inhibitor of aquaporins. This was not observed in hepatocytes from AQP9 knockout mice, nor observed by direct application of acetaldehyde to AQP9 expressed in Xenopus Laevis oocytes. Prolonged 24 hours exposure to either acetaldehyde or ethanol did not result in an increase in glycerol uptake by rat hepatocytes. Acetaldehyde decreased AQP9 mRNA and AQP9 protein, while ethanol decreased AQP9 mRNA but not AQP9 protein. Ethanol, but not acetaldehyde, increased the activities of glycerol kinase and phosphoenolpyruvate carboxykinase. Conclusions The acute effects of acetaldehyde, while mediated by AQP9, are probably influenced by binding of acetaldehyde to hepatocyte membranes and changes in cell permeability. The effects of ethanol in enhancing glucose kinase, and phosphoenolpyruvate carboxykinase leading to increased formation of glycerol-3-phosphate most likely contribute to alcoholic fatty liver. PMID:21294757

  1. Biological production of acetaldehyde from ethanol using non-growing Pichia pastoris whole cells

    SciTech Connect

    Chiang, Heien-Kun; Foutch, G.L.; Fish, W.W.

    1991-12-31

    Acetaldehyde has been produced biologically using whole-cell Pichia Pass in a semibatch fermentor. Ethanol and air were fed continuously, and the product, acetaldehyde, was removed by the air stream. Operation of the reactor exceeded 100 h, maintaining high alcohol oxidase activity. Low cell-mass concentration (9.9 g/L) minimized product inhibition. Ethanol concentration in the broth, oxygen concentration in the air, and pH were evaluated for their effects on the fermentation process.

  2. Atmospheric chemistry of toxic contaminants 2. Saturated aliphatics: Acetaldehyde, dioxane, ethylene glycol ethers, propylene oxide

    SciTech Connect

    Grosjean, D. )

    1990-11-01

    Detailed mechanisms are outlined for the chemical reactions that contribute to in-situ formation and atmospheric removal of the saturated aliphatic contaminants acetaldehyde, dioxane, ethylene glycol ethers (methyl, ethyl, n-butyl) and propylene oxide. In-situ formation is of major importance for acetaldehyde. In-situ removal involves reaction with OH (all compounds) and, for acetaldehyde, photolysis and reaction with NO{sub 3}. Acetaldehyde, dioxane, and the ethers are rapidly removed (half-lives of less than one day), leading to PAN (acetaldehyde) and to 2-oxodioxane and formaldehyde (dioxane). Reaction products of the glycol ethers include a large number of hydroxyesters, hydroxyacids, and hydroxycarbonyls. Propylene oxide reacts only slowly with OH, with an atmospheric half-life of 3 - 10 days, to yeild formaldehyde, acetaldehyde, and PAN. Uncertainties in the reaction mechanisms for dioxane, the glycol ethers, and propylene oxide are discussed and include C-C vs C-O bond scission in alkoxy radicals as well as alkoxy radical unimolecular decomposition vs reaction with oxygen.

  3. Protective Effect of Sodium Ferulate on Acetaldehyde-Treated Precision-Cut Rat Liver Slices

    PubMed Central

    Guo, Yu; Wu, Xiao-Qian; Zhang, Chun; Liao, Zhang-Xiu; Wu, Yong

    2012-01-01

    Abstract Activated hepatic stellate cells (HSCs) play a key role in hepatic fibrogenesis, and inhibition of HSC activation may prevent liver fibrosis. Acetaldehyde, the most deleterious metabolite of alcohol, triggers HSC activation in alcoholic liver injury. In the present study, we investigated the protective effect of sodium ferulate (SF), a sodium salt of ferulic acid that is rich in fruits and vegetables, on acetaldehyde-stimulated HSC activation using precision-cut liver slices (PCLSs). Rat PCLSs were co-incubated with 350 μM acetaldehyde and different concentrations of SF. Hepatotoxicity was assessed by measuring enzyme leakage and malondialdehyde content in tissue. α-Smooth muscle actin, transforming growth factor-β1, and hydroxyproline were determined to assess the activation of HSCs. In addition, matrix metalloproteinase (MMP)-1 and the tissue inhibitor of metalloproteinase (TIMP-1) were determined to evaluate collagen degradation. SF prominently prevented the enzyme leakage in acetaldehyde-treated slices and also inhibited HSC activation and collagen production stimulated by acetaldehyde. In addition, SF increased MMP-1 expression and decreased TIMP-1 expression. These results showed that SF protected PCLSs from acetaldehyde-stimulated HSC activation and liver injury, which may be associated with the attenuation of oxidative injury and acceleration of collagen degradation. PMID:22404575

  4. The total margin of exposure of ethanol and acetaldehyde for heavy drinkers consuming cider or vodka.

    PubMed

    Lachenmeier, Dirk W; Gill, Jan S; Chick, Jonathan; Rehm, Jürgen

    2015-09-01

    Heavy drinkers in Scotland may consume 1600 g ethanol per week. Due to its low price, cider may be preferred over other beverages. Anecdotal evidence has linked cider to specific health hazards beyond other alcoholic beverages. To examine this hypothesis, nine apple and pear cider samples were chemically analysed for constituents and contaminants. None of the products exceeded regulatory or toxicological thresholds, but the regular occurrence of acetaldehyde in cider was detected. To provide a quantitative risk assessment, two collectives of exclusive drinkers of cider and vodka were compared and the intake of acetaldehyde was estimated using probabilistic Monte-Carlo type analysis. The cider consumers were found to ingest more than 200-times the amount of acetaldehyde consumed by vodka consumers. The margins of exposure (MOE) of acetaldehyde were 224 for the cider and over 220,000 for vodka consumers. However, if the effects of ethanol were considered in a cumulative assessment of the combined MOE, the effect of acetaldehyde was minor and the combined MOE for both groups was 0.3. We suggest that alcohol policy priority should be given on reducing ethanol intake by measures such as minimum pricing, rather than to focus on acetaldehyde.

  5. Protective role of ALDH2 against acetaldehyde-derived DNA damage in oesophageal squamous epithelium.

    PubMed

    Amanuma, Yusuke; Ohashi, Shinya; Itatani, Yoshiro; Tsurumaki, Mihoko; Matsuda, Shun; Kikuchi, Osamu; Nakai, Yukie; Miyamoto, Shin'ichi; Oyama, Tsunehiro; Kawamoto, Toshihiro; Whelan, Kelly A; Nakagawa, Hiroshi; Chiba, Tsutomu; Matsuda, Tomonari; Muto, Manabu

    2015-01-01

    Acetaldehyde is an ethanol-derived definite carcinogen that causes oesophageal squamous cell carcinoma (ESCC). Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme that eliminates acetaldehyde, and impairment of ALDH2 increases the risk of ESCC. ALDH2 is produced in various tissues including the liver, heart, and kidney, but the generation and functional roles of ALDH2 in the oesophagus remain elusive. Here, we report that ethanol drinking increased ALDH2 production in the oesophagus of wild-type mice. Notably, levels of acetaldehyde-derived DNA damage represented by N(2)-ethylidene-2'-deoxyguanosine were higher in the oesophagus of Aldh2-knockout mice than in wild-type mice upon ethanol consumption. In vitro experiments revealed that acetaldehyde induced ALDH2 production in both mouse and human oesophageal keratinocytes. Furthermore, the N(2)-ethylidene-2'-deoxyguanosine levels increased in both Aldh2-knockout mouse keratinocytes and ALDH2-knockdown human keratinocytes treated with acetaldehyde. Conversely, forced production of ALDH2 sharply diminished the N(2)-ethylidene-2'-deoxyguanosine levels. Our findings provide new insight into the preventive role of oesophageal ALDH2 against acetaldehyde-derived DNA damage. PMID:26374466

  6. Implications of acetaldehyde-derived DNA adducts for understanding alcohol-related carcinogenesis.

    PubMed

    Balbo, Silvia; Brooks, Philip J

    2015-01-01

    Among various potential mechanisms that could explain alcohol carcinogenicity, the metabolism of ethanol to acetaldehyde represents an obvious possible mechanism, at least in some tissues. The fundamental principle of genotoxic carcinogenesis is the formation of mutagenic DNA adducts in proliferating cells. If not repaired, these adducts can result in mutations during DNA replication, which are passed on to cells during mitosis. Consistent with a genotoxic mechanism, acetaldehyde does react with DNA to form a variety of different types of DNA adducts. In this chapter we will focus more specifically on N2-ethylidene-deoxyguanosine (N2-ethylidene-dG), the major DNA adduct formed from the reaction of acetaldehyde with DNA and specifically highlight recent data on the measurement of this DNA adduct in the human body after alcohol exposure. Because results are of particular biological relevance for alcohol-related cancer of the upper aerodigestive tract (UADT), we will also discuss the histology and cytology of the UADT, with the goal of placing the adduct data in the relevant cellular context for mechanistic interpretation. Furthermore, we will discuss the sources and concentrations of acetaldehyde and ethanol in different cell types during alcohol consumption in humans. Finally, in the last part of the chapter, we will critically evaluate the concept of carcinogenic levels of acetaldehyde, which has been raised in the literature, and discuss how data from acetaldehyde genotoxicity are and can be utilized in physiologically based models to evaluate exposure risk. PMID:25427902

  7. Implications of acetaldehyde-derived DNA adducts for understanding alcohol-related carcinogenesis.

    PubMed

    Balbo, Silvia; Brooks, Philip J

    2015-01-01

    Among various potential mechanisms that could explain alcohol carcinogenicity, the metabolism of ethanol to acetaldehyde represents an obvious possible mechanism, at least in some tissues. The fundamental principle of genotoxic carcinogenesis is the formation of mutagenic DNA adducts in proliferating cells. If not repaired, these adducts can result in mutations during DNA replication, which are passed on to cells during mitosis. Consistent with a genotoxic mechanism, acetaldehyde does react with DNA to form a variety of different types of DNA adducts. In this chapter we will focus more specifically on N2-ethylidene-deoxyguanosine (N2-ethylidene-dG), the major DNA adduct formed from the reaction of acetaldehyde with DNA and specifically highlight recent data on the measurement of this DNA adduct in the human body after alcohol exposure. Because results are of particular biological relevance for alcohol-related cancer of the upper aerodigestive tract (UADT), we will also discuss the histology and cytology of the UADT, with the goal of placing the adduct data in the relevant cellular context for mechanistic interpretation. Furthermore, we will discuss the sources and concentrations of acetaldehyde and ethanol in different cell types during alcohol consumption in humans. Finally, in the last part of the chapter, we will critically evaluate the concept of carcinogenic levels of acetaldehyde, which has been raised in the literature, and discuss how data from acetaldehyde genotoxicity are and can be utilized in physiologically based models to evaluate exposure risk.

  8. Protective role of ALDH2 against acetaldehyde-derived DNA damage in oesophageal squamous epithelium

    PubMed Central

    Amanuma, Yusuke; Ohashi, Shinya; Itatani, Yoshiro; Tsurumaki, Mihoko; Matsuda, Shun; Kikuchi, Osamu; Nakai, Yukie; Miyamoto, Shin’ichi; Oyama, Tsunehiro; Kawamoto, Toshihiro; Whelan, Kelly A.; Nakagawa, Hiroshi; Chiba, Tsutomu; Matsuda, Tomonari; Muto, Manabu

    2015-01-01

    Acetaldehyde is an ethanol-derived definite carcinogen that causes oesophageal squamous cell carcinoma (ESCC). Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme that eliminates acetaldehyde, and impairment of ALDH2 increases the risk of ESCC. ALDH2 is produced in various tissues including the liver, heart, and kidney, but the generation and functional roles of ALDH2 in the oesophagus remain elusive. Here, we report that ethanol drinking increased ALDH2 production in the oesophagus of wild-type mice. Notably, levels of acetaldehyde-derived DNA damage represented by N2-ethylidene-2′-deoxyguanosine were higher in the oesophagus of Aldh2-knockout mice than in wild-type mice upon ethanol consumption. In vitro experiments revealed that acetaldehyde induced ALDH2 production in both mouse and human oesophageal keratinocytes. Furthermore, the N2-ethylidene-2′-deoxyguanosine levels increased in both Aldh2-knockout mouse keratinocytes and ALDH2-knockdown human keratinocytes treated with acetaldehyde. Conversely, forced production of ALDH2 sharply diminished the N2-ethylidene-2′-deoxyguanosine levels. Our findings provide new insight into the preventive role of oesophageal ALDH2 against acetaldehyde-derived DNA damage. PMID:26374466

  9. Increased frequencies of micronucleated reticulocytes and T-cell receptor mutation in Aldh2 knockout mice exposed to acetaldehyde.

    PubMed

    Kunugita, Naoki; Isse, Toyohi; Oyama, Tsunehiro; Kitagawa, Kyoko; Ogawa, Masanori; Yamaguchi, Tetsunosuke; Kinaga, Tsuyoshi; Kawamoto, Toshihiro

    2008-02-01

    Aldehyde dehydrogenase-2 (ALDH2) metabolizes acetaldehyde produced from ethanol into acetate and plays a major role in the oxidation of acetaldehyde in vivo. About half of all Japanese people have inactive ALDH2. We generated homozygous Aldh2 null (Aldh2-/-) mice by gene targeting knockout as a model of ALDH2-deficient humans. To investigate the mutagenicity of acetaldehyde, a micronucleus assay and a T-cell receptor (TCR) gene mutation assay were performed in Aldh2-/- mice and wild-type (Aldh2 +/+) mice exposed to acetaldehyde. The mice were continuously exposed to 125 and 500 ppm of acetaldehyde vapor for 2 weeks. Another group was orally administered 100 mg/kg once a day for 2 weeks continuously. The mice were killed after 2 weeks of exposure to acetaldehyde, and the frequency of micronucleated reticulocytes was measured by flow cytometry. We also observed the incidence of TCR gene mutations in T-lymphocytes by measuring the variant CD3(-CD4+) expression by flow cytometry. The frequency of micronucleated reticulocytes induced by acetaldehyde was significantly increased in Aldh2 -/- mice, but not in Aldh2 +/+ mice. TCR mutant frequency was also associated with acetaldehyde exposure in Aldh2-/ - mice, especially after oral administration; however, it was not associated with acetaldehyde exposure in Aldh2 +/+ mice. In conclusion, Aldh2 -/- mice showed high sensitivity in the micronuclei and TCR mutation assays compared with Aldh2 +/+ mice after exposure to acetaldehyde. PMID:18303182

  10. Putative role of brain acetaldehyde in ethanol addiction

    PubMed Central

    Deng, Xin-sheng; Deitrich, Richard A.

    2008-01-01

    The putative contribution of brain acetaldehyde (AcH) to ethanol (EtOH) tolerance and dependence (addiction) is reviewed. Although the role of AcH in EtOH addiction has been controversial, there are data showing a relationship. AcH can be formed in the brain tissues through the peroxidatic activity of catalase and by oxidation via other oxidizing enzymes such as cytochrome P-4502E1. Significant formation of AcH occurs in vitro in brain tissue at concentrations of EtOH that can be achieved by voluntary consumption of EtOH by rodents. AcH itself possesses reinforcing properties, which suggests that some of the behavioral pharmacological effects attributed to EtOH may be a result of the formation of AcH, and supports the involvement of AcH in EtOH addiction. Modulation of aldehyde dehydrogenase (ALDH) and brain catalase activity can change EtOH-related addictive behaviors presumably by changing AcH levels. Moreover, some condensation reaction products of AcH may promote some actions of EtOH and its consumption. On the basis of the findings, it can be concluded that AcH may mediate some of the CNS actions of EtOH including tolerance and dependence, although further exploration the involvement of AcH in EtOH addiction is warranted. PMID:19122804

  11. Theoretical survey of the reaction between osmium and acetaldehyde

    NASA Astrophysics Data System (ADS)

    Dai, Guo-Liang; Wang, Chuan-Feng

    2012-05-01

    The mechanism of the reaction of osmium atom with acetaldehyde has been investigated with a DFT approach. All the stationary points are determined at the UB3LYP/ sdd/6-311++G** level of the theory. Both ground and excited state potential energy surfaces are investigated in detail. The present results show that the title reaction start with the formation of a CH3CHO-metal complex followed by C-C, aldehyde C-H, C-O, and methyl C-H activation. These reactions can lead to four different products (HOsCH3 + CO, OsCO + CH4, OsCOCH3 + H, and OsO + C2H4). The minimum energy reaction path is found to involve the spin inversion in the initial reaction step. This potential energy curve-crossing dramatically affects reaction exothermic. The present results may be helpful in understanding the mechanism of the title reaction and further experimental investigation of the reaction.

  12. Acetaldehyde involvement in ethanol's postabsortive effects during early ontogeny

    PubMed Central

    March, Samanta M.; Abate, P.; Molina, Juan C.

    2013-01-01

    Clinical and biomedical studies sustains the notion that early ontogeny is a vulnerable window to the impact of alcohol. Experiences with the drug during these stages increase latter disposition to prefer, use or abuse ethanol. This period of enhanced sensitivity to ethanol is accompanied by a high rate of activity in the central catalase system, which metabolizes ethanol in the brain. Acetaldehyde (ACD), the first oxidation product of ethanol, has been found to share many neurobehavioral effects with the drug. Cumulative evidence supports this notion in models employing adults. Nevertheless very few studies have been conducted to analyze the role of ACD in ethanol postabsorptive effects, in newborns or infant rats. In this work we review recent experimental literature that syndicates ACD as a mediator agent of reinforcing aspects of ethanol, during early ontogenetic stages. We also show a meta-analytical correlational approach that proposes how differences in the activity of brain catalase across ontogeny, could be modulating patterns of ethanol consumption. PMID:23801947

  13. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    PubMed

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation. PMID:26971669

  14. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    PubMed

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation.

  15. Acetone in the atmosphere: Distribution, sources, and sinks

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; O'Hara, D.; Herlth, D.; Sachse, W.; Blake, D. R.; Bradshaw, J. D.; Kanakidou, M.; Crutzen, P. J.

    1994-01-01

    Acetone (CH3COCH3) was found to be the dominant nonmethane organic species present in the atmosphere sampled primarily over eastern Canada (0-6 km, 35 deg-65 deg N) during ABLE3B (July to August 1990). A concentration range of 357 to 2310 ppt (= 10(exp -12) v/v) with a mean value of 1140 +/- 413 ppt was measured. Under extremely clean conditions, generally involving Arctic flows, lowest (background) mixing ratios of 550 +/- 100 ppt were present in much of the troposphere studied. Correlations between atmospheric mixing ratios of acetone and select species such as C2H2, CO, C3H8, C2Cl4 and isoprene provided important clues to its possible sources and to the causes of its atmospheric variability. Biomass burning as a source of acetone has been identified for the first time. By using atmospheric data and three-dimensional photochemical models, a global acetone source of 40-60 Tg (= 10(exp 12) g)/yr is estimated to be present. Secondary formation from the atmospheric oxidation of precursor hydrocarbons (principally propane, isobutane, and isobutene) provides the single largest source (51%). The remainder is attributable to biomass burning (26%), direct biogenic emissions (21%), and primary anthropogenic emissions (3%). Atmospheric removal of acetone is estimated to be due to photolysis (64%), reaction with OH radicals (24%), and deposition (12%). Model calculations also suggest that acetone photolysis contributed significantly to PAN formation (100-200 ppt) in the middle and upper troposphere of the sampled region and may be important globally. While the source-sink equation appears to be roughly balanced, much more atmospheric and source data, especially from the southern hemisphere, are needed to reliably quantify the atmospheric budget of acetone.

  16. Acetone in the upper troposphere and lower stratosphere: Impact on trace gases and aerosols

    NASA Astrophysics Data System (ADS)

    Arnold, F.; Bürger, V.; Droste-Fanke, B.; Grimm, F.; Krieger, A.; Schneider, J.; Stilp, T.

    Upper tropospheric and lower stratospheric acetone measurements have been performed in summer and winter 1994 through 1996 at latitudes between 30°N and 75°N using ion-molecule reaction mass spectrometry. We observed very high acetone volume mixing ratios of up to 3000 pptv (parts per trillion by volume) in extended air masses and in summer when acetone destruction by photodissociation is fast. This indicates efficient transport of acetone and photochemical acetone precursors to the upper troposphere and efficient upper tropospheric formation of acetone products, especially HOx radicals and PAN. Our data indicate large HOx production from acetone which has important implications for other trace gases and aerosols.

  17. Biogenic and biomass burning sources of acetone to the troposphere

    SciTech Connect

    Atherton, C.S.

    1997-04-01

    Acetone may be an important source of reactive odd hydrogen in the upper troposphere and lower stratosphere. This source of odd hydrogen may affect the concentration of a number of species, including ozone, nitrogen oxides, methane, and others. Traditional, acetone had been considered a by-product of the photochemical oxidation of other species, and had not entered models as a primary emission. However, recent work estimates a global source term of 40-60 Tg acetone/year. Of this, 25% is directly emitted during biomass burning, and 20% is directly emitted by evergreens and other plants. Only 3% is due to anthropogenic/industrial emissions. The bulk of the remainder, 51% of the acetone source, is a secondary product from the oxidation of propane, isobutane, and isobutene. Also, while it is speculated that the oxidation of pinene (a biogenic emission) may also contribute about 6 Tg/year, this term is highly uncertain. Thus, the two largest primary sources of acetone are biogenic emission and biomass burning, with industrial/anthropogenic emissions very small in comparison.

  18. Sensor gas analyzer for acetone determination in expired air

    NASA Astrophysics Data System (ADS)

    Baranov, Vitaly V.

    2001-05-01

    Diseases and changes in the way of life change the concentration and composition of the expired air. Our adaptable gas analyzer is intended for the selective analysis of expired air and can be adapted for the solution of current diagnostic and analytical tasks by the user (a physician or a patient). Having analyzed the existing trends in the development of noninvasive diagnostics we have chosen the method of noninvasive acetone detection in expired air, where the acetone concentration correlates with blood and urine glucose concentrations. The appearance of acetone in expired air is indicative of disorders that may be caused not only by diabetes but also be wrong diet, incorrect sportsmen training etc. To control the disorders one should know the acetone concentration in the human body. This knowledge allows one to judge upon the state of the patient, choose a correct diet that will not cause damage to the patient's health, determine sportsmen training efficiency and results and solve the artificial pancreas problem. Our device provide highly accurate analysis, rapid diagnostics and authentic acetone quantification in the patient's body at any time aimed at prediction of the patient's state and assessing the efficiency of the therapy used. Clinical implementation of the device will improve the health and save lives of many thousands of diabetes sufferers.

  19. Methanol from coal

    NASA Technical Reports Server (NTRS)

    Miller, D. R.

    1978-01-01

    Economic feasibility of methanol or methyl fuel produced from coal using existing technology is discussed. Other factors considered include environmental, safety, toxicity, transportation, so storage, ease of burning, and retrofitting of present boilers. Demonstrations of its uses as a boiler fuel and as a turbine fuel are cited.

  20. Nitrate-Dependent Degradation of Acetone by Alicycliphilus and Paracoccus Strains and Comparison of Acetone Carboxylase Enzymes ▿

    PubMed Central

    Dullius, Carlos Henrique; Chen, Ching-Yuan; Schink, Bernhard

    2011-01-01

    A novel acetone-degrading, nitrate-reducing bacterium, strain KN Bun08, was isolated from an enrichment culture with butanone and nitrate as the sole sources of carbon and energy. The cells were motile short rods, 0.5 to 1 by 1 to 2 μm in size, which gave Gram-positive staining results in the exponential growth phase and Gram-negative staining results in the stationary-growth phase. Based on 16S rRNA gene sequence analysis, the isolate was assigned to the genus Alicycliphilus. Besides butanone and acetone, the strain used numerous fatty acids as substrates. An ATP-dependent acetone-carboxylating enzyme was enriched from cell extracts of this bacterium and of Alicycliphilus denitrificans K601T by two subsequent DEAE Sepharose column procedures. For comparison, acetone carboxylases were enriched from two additional nitrate-reducing bacterial species, Paracoccus denitrificans and P. pantotrophus. The products of the carboxylase reaction were acetoacetate and AMP rather than ADP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of cell extracts and of the various enzyme preparations revealed bands corresponding to molecular masses of 85, 78, and 20 kDa, suggesting similarities to the acetone carboxylase enzymes described in detail for the aerobic bacterium Xanthobacter autotrophicus strain Py2 (85.3, 78.3, and 19.6 kDa) and the phototrophic bacterium Rhodobacter capsulatus. Protein bands were excised and compared by mass spectrometry with those of acetone carboxylases of aerobic bacteria. The results document the finding that the nitrate-reducing bacteria studied here use acetone-carboxylating enzymes similar to those of aerobic and phototrophic bacteria. PMID:21841031

  1. Acetaldehyde self-administration by a two-bottle choice paradigm: consequences on emotional reactivity, spatial learning, and memory.

    PubMed

    Plescia, Fulvio; Brancato, Anna; Venniro, Marco; Maniaci, Giuseppe; Cannizzaro, Emanuele; Sutera, Flavia Maria; De Caro, Viviana; Giannola, Libero Italo; Cannizzaro, Carla

    2015-03-01

    Acetaldehyde, the first alcohol metabolite, is responsible for many pharmacological effects that are not clearly distinguishable from those exerted by its parent compound. It alters motor performance, induces reinforced learning and motivated behavior, and produces different reactions according to the route of administration and the relative accumulation in the brain or in the periphery. The effective activity of oral acetaldehyde represents an unresolved field of inquiry that deserves further investigation. Thus, this study explores the acquisition and maintenance of acetaldehyde drinking behavior in adult male rats, employing a two-bottle choice paradigm for water and acetaldehyde solution (from 0.9% to 3.2% v/v), over 8 weeks. The behavioral consequences exerted by chronic acetaldehyde intake are assessed by a set of different tests: trials in an open-field arena and elevated-plus maze provided information on both general motor and explorative activity, and anxiety-driven behavioral responses. The Morris water maze allowed the exploration of cognitive processes such as spatial learning and memory. Determination of acetaldehyde levels in the brain was carried out at the end of the drinking paradigm. Our results indicate that rats exposed for the first time to acetaldehyde at 0.9% displayed a regular and stable daily drinking pattern that reached higher values and a "peaks and drops" shaped-trend when acetaldehyde concentration was increased to 3.2%. Accordingly, an increase in acetaldehyde levels in the brain was determined compared to non-acetaldehyde drinking rats. Acetaldehyde intake during the free-choice paradigm exerted an anxiogenic response in the open-field arena and elevated-plus maze, which in turn correlates with an enhancement in cognitive flexibility and spatial orientation skills, when an adaptive response to a stressful environmental challenge was required. These findings further support the idea that acetaldehyde is indeed a centrally active and

  2. Stability of acetaldehyde-derived DNA adduct in vitro.

    PubMed

    Hori, Kimiko; Miyamoto, Shin'ichi; Yukawa, Yoshiyuki; Muto, Manabu; Chiba, Tsutomu; Matsuda, Tomonari

    2012-07-13

    Acetaldehyde (AA) derived from alcoholic beverages is a confirmed carcinogen for esophageal and head and neck cancers. AA forms various DNA adducts and is thought to play a crucial role in carcinogenesis. Transient DNA adducts are usually repaired, but the stability of AA-derived DNA adducts has not been elucidated. We investigated the stability of N(2)-ethylidene-2'-deoxyguanosine (N(2)-ethylidene-dG), a major AA-derived DNA adduct, in cultured cells. First, to determine the optimal concentration of AA for detecting N(2)-ethylidene-dG in cell culture, a dose-response study was performed using HL60 cells of the human promyelocytic leukemia cell line. An AA concentration ≥ 0.01% (1.8 mM) was required to detect N(2)-ethylidene-dG in vitro. We next examined the stability of N(2)-ethylidene-dG. After a 1 or 2h exposure to 0.01% of AA in a tightly sealed bottle, N(2)-ethylidene-dG content was measured by sensitive liquid chromatography tandem mass spectrometry immediately, 24h, and 48 h after exposure. After the 1h exposure, the mean (± SD) N(2)-ethylidene-dG contents were 12.1 ± 1.28, 8.20 ± 0.64, and 6.70 ± 0.52 adducts per 10(7) bases at each postexposure time. After the 2h exposure, N(2)-ethylidene-dG content increased to 21.4 ± 7.50, 10.5 ± 3.61, and 9.83 ± 3.90 adducts per 10(7) bases at each postexposure time. The half-life of this adduct was calculated as ∼35 h in independent experiments. These results indicate that AA exposure from daily alcohol consumption may cause DNA damage and may increase the risk of alcohol-related carcinogenesis. PMID:22683642

  3. Acetone Powder From Dormant Seeds of Ricinus communis L

    NASA Astrophysics Data System (ADS)

    Cavalcanti, Elisa D. C.; Maciel, Fábio M.; Villeneuve, Pierre; Lago, Regina C. A.; Machado, Olga L. T.; Freire, Denise M. G.

    The influence of several factors on the hydrolytic activity of lipase, present in the acetone powder from dormant castor seeds (Ricinus communis) was evaluated. The enzyme showed a marked specificity for short-chain substrates. The best reaction conditions were an acid medium, Triton X-100 as the emulsifying agent and a temperature of 30°C. The lipase activity of the acetone powder of different castor oil genotypes showed great variability and storage stability of up to 90%. The toxicology analysis of the acetone powder from genotype Nordestina BRS 149 showed a higher ricin (toxic component) content, a lower 2S albumin (allergenic compound) content, and similar allergenic potential compared with untreated seeds.

  4. Specific Anion Effects on the Kinetics of Iodination of Acetone.

    PubMed

    Lo Nostro, Pierandrea; Mazzini, Virginia; Ninham, Barry W; Ambrosi, Moira; Dei, Luigi; Baglioni, Piero

    2016-08-18

    Specific ion effects on the kinetics of iodination of acetone in an acidic medium are investigated by UV/Vis spectrophotometry as a function of nature of the acid and temperature. The results indicate that the order of the reaction with respect to acetone is practically unaffected by the composition of the acid while the value of the mixed constant k1 K increases according to the sequence HBr

  5. Acne vulgaris: treatment with topical benzoyl peroxide acetone gel.

    PubMed

    Montes, L F

    1977-05-01

    The topical effect on acne of a benzoyl peroxide acetone gel was studied over an eight week period and simultaneously compared with the effect of a benzoyl peroxide lotion and a vitamin A acid cream. The three formulations produced a significant reduction in the number of comedones. The two benzoyl peroxide formulations substantially reduced the number of papules, but this effect was not observed to a significant degree with the vitamin A acid. Burning sensation following application, a common problem with the benzoyl peroxide alcohol gels, was not reported by patients using the benzoyl peroxide acetone gel.

  6. Mechanistic understanding of hydrogenation of acetaldehyde on Au(111): A DFT investigation

    NASA Astrophysics Data System (ADS)

    Meng, Qingsen; Shen, Yongli; Xu, Jing; Ma, Xinbin; Gong, Jinlong

    2012-11-01

    This paper describes the reaction pathways for hydrogenation of acetaldehyde on atomic hydrogen pre-adsorbed Au(111) employing density functional theory (DFT) calculations. All the surface species involved in the reaction scheme have low diffusion barriers, suggesting that the rearrangement and movement of these species on the surface are facile under reaction condition. The hydroxyethyl is proposed to be the intermediate for the hydrogenation of acetaldehyde, and the activation energy for its formation is 0.37 eV. Additionally, the coupling reaction of hydroxyethyl and acetaldehyde - resulting in the formation of the ethylidene ethylene glycol (CH3C*HOCH(CH3)OH) species - also readily occurs at the reaction condition. Two-dimensional (2-D) polyacetaldehyde ((CH3CHO)2) can be easily hydrogenated to ethylidene ethylene glycol or ethoxy hemiacetal (CH3CH2OCH(CH3)O*); the latter can be converted to ethanol and acetaldehyde via further hydrogenation. As the hydrogenation products of ethylidene ethylene glycol and ethoxy hemiacetal, ethoxyethanol (CH3CH2OCH(CH3)OH) can be deeply hydrogenated to hydroxyethyl and ethanol. Our calculations also suggest that the formation of an ethoxyl intermediate is not likely, which agrees with the experimental observation that no deuterated acetaldehydes have been detected in isotopic measurements.

  7. Adsorption and Reaction of Acetaldehyde on Stoichiometric and Defective SrTiO₃(100) Surfaces

    SciTech Connect

    Wang, Li Q.; Ferris, Kim F.; Azad, Samina; Engelhard, Mark H.; Peden, Charles HF.

    2004-02-05

    The adsorption and reaction of acetaldehyde (CH{sub 3}CHO), on stoichiometric (TiO{sub 2}-terminated) and reduced SrTiO{sub 3}(100) surfaces, have been investigated using temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Acetaldehyde adsorbs molecularly on the stoichiometric SrTiO{sub 3}(100) surface that contains predominantly Ti{sup 4+} cations. The Ti{sup 4+} sites on the stoichiometric SrTiO{sub 3}(100) surface are not sufficiently active for surface reactions such as aldol condensation, as opposed to the Ti{sup 4+} ions on the TiO{sub 2}(001) surface. However, decomposition and redox reactions of acetaldehyde occur in the presence of surface defects created by Ar{sup +} sputtering. The decomposition products following reactions of acetaldehyde on the defective surface include H{sub 2}, C{sub 2}H{sub 4}, CO, C{sub 4}H{sub 6}, and C{sub 4}H{sub 8}. Reductive coupling, to produce C{sub 2}H{sub 4} and C{sub 4}H{sub 8} is the main reaction pathway for decomposition of acetaldehyde on the sputter reduced SrTiO{sub 3}(100) surface.

  8. Effect of chronic acetaldehyde intoxication on ethanol tolerance and membrane fatty acids.

    PubMed

    Latge, C; Lamboeuf, Y; Roumec, C; de Saint Blanquat, G

    1987-09-01

    Recent studies have suggested that acetaldehyde participates directly in the pathogenesis of alcoholism. Its action has been attributed mainly to its physico-chemical properties. Results of direct intoxication of laboratory animals with acetaldehyde have been reported, but only for short periods of exposure and at high doses. These are probably not representative of the conditions found during alcohol intoxication. The pulmonary route of administration described here enables long term intoxication with acetaldehyde, at levels corresponding to values measured during chronic ethanol intoxication. Chronic administration of acetaldehyde during 3 weeks induced a metabolic tolerance to ethanol as tested by the sleeping time after a challenge dose of ethanol; behavioural tolerance (measured by blood alcohol levels on waking) was not observed. At the end of the intoxication, phospholipid fatty acids of erythrocyte and synaptosome membranes were also analysed. Small changes in levels of the shorter fatty acids were observed in the phosphatidyl-choline fraction. By comparison with the effects of ethanol on the same membrane preparations, only a small part of this effect can be attributed to acetaldehyde. The first metabolite of ethanol has, however, a sure effect on the pattern of fatty acid phospholipids.

  9. Dissociative electron attachments to ethanol and acetaldehyde: A combined experimental and simulation study

    SciTech Connect

    Wang, Xu-Dong; Xuan, Chuan-Jin; Feng, Wen-Ling; Tian, Shan Xi

    2015-02-14

    Dissociation dynamics of the temporary negative ions of ethanol and acetaldehyde formed by the low-energy electron attachments is investigated by using the anion velocity map imaging technique and ab initio molecular dynamics simulations. The momentum images of the dominant fragments O{sup −}/OH{sup −} and CH{sub 3}{sup −} are recorded, indicating the low kinetic energies of O{sup −}/OH{sup −} for ethanol while the low and high kinetic energy distributions of O{sup −} ions for acetaldehyde. The CH{sub 3}{sup −} image for acetaldehyde also shows the low kinetic energy. With help of the dynamics simulations, the fragmentation processes are qualitatively clarified. A new cascade dissociation pathway to produce the slow O{sup −} ion via the dehydrogenated intermediate, CH{sub 3}CHO{sup −} (acetaldehyde anion), is proposed for the dissociative electron attachment to ethanol. After the electron attachment to acetaldehyde molecule, the slow CH{sub 3}{sup −} is produced quickly in the two-body dissociation with the internal energy redistributions in different aspects before bond cleavages.

  10. Optical properties of polyaniline-coated silica spheres: aging effect in acetone

    NASA Astrophysics Data System (ADS)

    Kim, Byoung-Wu; Kim, Sang-Jo; Kang, So-Yeon; Moon, Sang-Hyeon; Park, Eun-Hye; Kang, Kwang-Sun

    2015-10-01

    Polyaniline (PAn)-coated silica spheres have been synthesized by attaching various amounts of N-[3- (trimethoxysilyl)propyl]aniline (TMSPA) and polymerizing with ammonium persulfate. The ratios of tetraethoxy orthosilicate and TMSPA were 10:1 (PAn-A), 5:1 (PAn-B), and 3:1 (PAn-C). After polymerization of the aniline moieties the -OH absorption peak drastically reduced and the new sharp peaks appeared at 1398 cm-1 and 617 cm-1 representing C-N and C-S stretching vibrations, respectively. The polymerized spheres were soaked into the acetone for three months. New absorption peak at 1712 cm-1 representing C=O stretching vibration of an ester appears after three months storage in acetone and becomes stronger with the smaller amount of PAn. Although the sphere film color is gray when it is dried, the color turned to dark when it was wetted with methanol. Complicated solvatochromic behavior was observed for whole UV-visible range depending on the solvent. The solution color changed from clear to dark brown, brown, and yellow for the PAnA, PAnB and PAnC, respectively. The absorption peaks of the dried solution for PAn-A and PAn-B at 3230, 2972, 2926, 1712, 1434/1377, and 1051 cm-1 represent C-OH, R-CH3, R2-CH2, -C=O, C-H, and Si- O-Si absorption, respectively. Photoluminescence peak of the solution shifted toward longer wavelength with the decrease the amount of PAn. The sequence of the amount of new material formation is PAn-A > PAn-B > PAn-C.

  11. Eucomic acid methanol monosolvate

    PubMed Central

    Li, Guo-Qiang; Li, Yao-Lan; Wang, Guo-Cai; Liang, Zhi-Hong; Jiang, Ren-Wang

    2011-01-01

    In the crystal structure of the title compound [systematic name: 2-hy­droxy-2-(4-hy­droxy­benz­yl)butane­dioic acid methanol monosolvate], C11H12O6·CH3OH, the dihedral angles between the planes of the carboxyl groups and the benzene ring are 51.23 (9) and 87.97 (9)°. Inter­molecular O—H⋯O hydrogen-bonding inter­actions involving the hy­droxy and carb­oxy­lic acid groups and the methanol solvent mol­ecule give a three-dimensional structure. PMID:22091200

  12. The ethanol metabolite acetaldehyde induces water and salt intake via two distinct pathways in the central nervous system of rats.

    PubMed

    Ujihara, Izumi; Hitomi, Suzuro; Ono, Kentaro; Kakinoki, Yasuaki; Hashimoto, Hirofumi; Ueta, Yoichi; Inenaga, Kiyotoshi

    2015-12-01

    The sensation of thirst experienced after heavy alcohol drinking is widely regarded as a consequence of ethanol (EtOH)-induced diuresis, but EtOH in high doses actually induces anti-diuresis. The present study was designed to investigate the introduction mechanism of water and salt intake after heavy alcohol drinking, focusing on action of acetaldehyde, a metabolite of EtOH and a toxic substance, using rats. The aldehyde dehydrogenase (ALDH) inhibitor cyanamide was used to mimic the effect of prolonged acetaldehyde exposure because acetaldehyde is quickly degraded by ALDH. Systemic administration of a high-dose of EtOH at 2.5 g/kg induced water and salt intake with anti-diuresis. Cyanamide enhanced the fluid intake following EtOH and acetaldehyde administration. Systemic administration of acetaldehyde with cyanamide suppressed blood pressure and increased plasma renin activity. Blockade of central angiotensin receptor AT1R suppressed the acetaldehyde-induced fluid intake and c-Fos expression in the circumventricular organs (CVOs), which form part of dipsogenic mechanism in the brain. In addition, central administration of acetaldehyde together with cyanamide selectively induced water but not salt intake without changes in blood pressure. In electrophysiological recordings from slice preparations, acetaldehyde specifically excited angiotensin-sensitive neurons in the CVO. These results suggest that acetaldehyde evokes the thirst sensation following heavy alcohol drinking, by two distinct and previously unsuspected mechanisms, independent of diuresis. First acetaldehyde indirectly activates AT1R in the dipsogenic centers via the peripheral renin-angiotensin system following the depressor response and induces both water and salt intake. Secondly acetaldehyde directly activates neurons in the dipsogenic centers and induces only water intake.

  13. The toxicity of methanol

    SciTech Connect

    Tephly, T.R. )

    1991-01-01

    Methanol toxicity in humans and monkeys is characterized by a latent period of many hours followed by a metabolic acidosis and ocular toxicity. This is not observed in most lower animals. The metabolic acidosis and blindness is apparently due to formic acid accumulation in humans and monkeys, a feature not seen in lower animals. The accumulation of formate is due to a deficiency in formate metabolism which is, in turn, related, in part, to low hepatic tetrahydrofolate (H{sub 4}folate). An excellent correlation between hepatic H{sub 4} folate and formate oxidation rates has been shown within and across species. Thus, humans and monkeys possess low hepatic H{sub 4}folate levels, low rates of formate oxidation and accumulation of formate after methanol. Formate, itself, produces blindness in monkeys in the absence of metabolic acidosis. In addition to low hepatic H{sub 4}folate concentrations, monkeys and humans also have low hepatic 10-formyl H{sub 4}folate dehydrogenase levels, the enzyme which is the ultimate catalyst for conversion of formate to carbon dioxide. This review presents the basis for the role of folic acid-dependent reactions in the regulation of methanol toxicity.

  14. California methanol assessment. Volume 2: Technical report

    NASA Technical Reports Server (NTRS)

    Otoole, R.; Dutzi, E.; Gershman, R.; Heft, R.; Kalema, W.; Maynard, D.

    1983-01-01

    Energy feedstock sources for methanol; methanol and other synfuels; transport, storage, and distribution; air quality impact of methanol use in vehicles, chemical methanol production and use; methanol utilization in vehicles; methanol utilization in stationary applications; and environmental and regulatory constraints are discussed.

  15. Impact of bioethanol fuel implementation in transport based on modelled acetaldehyde concentration in the urban environment.

    PubMed

    Sundvor, Ingrid; López-Aparicio, Susana

    2014-10-15

    This study shows the results obtained from emission and air dispersion modelling of acetaldehyde in the city of Oslo and associated with the circulation of bioethanol vehicles. Two scenarios of bioethanol implementation, both realistic and hypothetical, have been considered under winter conditions; 1) realistic baseline scenario, which corresponds to the current situation in Oslo where one bus line is running with bioethanol (E95; 95% ethanol-5% petrol) among petrol and diesel vehicles; and 2) a hypothetical scenario characterized by a full implementation of high-blend bioethanol (i.e. E85) as fuel for transportation, and thus an entire bioethanol fleet. The results indicate that a full implementation of bioethanol will have a certain impact on urban air quality due to direct emissions of acetaldehyde. Acetaldehyde emissions are estimated to increase by 233% and concentration levels increase up to 650% with regard to the baseline. PMID:25064718

  16. Feasibility studies of a fuel cell for cogeneration of homogeneously catalyzed acetaldehyde and electricity from ethanol

    SciTech Connect

    Malhotra, S.; Datta, R.

    1996-10-01

    The development and feasibility of a novel fuel cell for simultaneously generating electricity and homogeneously catalyzed acetaldehyde from ethanol are reported. The fuel cell is based on the supported molten-salt electrocatalysis technique that allows use of homogeneous (liquid-phase) catalysts in fuel cells for the first time. The electrocatalytic reaction combines the chemistry of the Wacker process conventionally used for acetaldehyde production from the partial oxidation of ethylene and that of the Veba-Chemie method. Nafion membranes impregnated with different electrolytic materials were used in the fuel cell as electrolytes to allow operation at reaction temperatures up to 165 C. Results obtained are comparable to those reported in the literature on partial oxidation of ethylene to acetaldehyde in a fuel cell based on conventional heterogeneous electrocatalysts.

  17. Redirection of the Reaction Specificity of a Thermophilic Acetolactate Synthase toward Acetaldehyde Formation

    PubMed Central

    Cheng, Maria; Yoshiyasu, Hayato; Okano, Kenji; Ohtake, Hisao; Honda, Kohsuke

    2016-01-01

    Acetolactate synthase and pyruvate decarboxylase are thiamine pyrophosphate-dependent enzymes that convert pyruvate into acetolactate and acetaldehyde, respectively. Although the former are encoded in the genomes of many thermophiles and hyperthermophiles, the latter has been found only in mesophilic organisms. In this study, the reaction specificity of acetolactate synthase from Thermus thermophilus was redirected to catalyze acetaldehyde formation to develop a thermophilic pyruvate decarboxylase. Error-prone PCR and mutant library screening led to the identification of a quadruple mutant with 3.1-fold higher acetaldehyde-forming activity than the wild-type. Site-directed mutagenesis experiments revealed that the increased activity of the mutant was due to H474R amino acid substitution, which likely generated two new hydrogen bonds near the thiamine pyrophosphate-binding site. These hydrogen bonds might result in the better accessibility of H+ to the substrate-cofactor-enzyme intermediate and a shift in the reaction specificity of the enzyme. PMID:26731734

  18. One-pot microbial synthesis of 2'-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase.

    PubMed

    Horinouchi, Nobuyuki; Ogawa, Jun; Kawano, Takako; Sakai, Takafumi; Saito, Kyota; Matsumoto, Seiichiro; Sasaki, Mie; Mikami, Yoichi; Shimizu, Sakayu

    2006-06-01

    A one-pot enzymatic synthesis of 2'-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase was established. Glycolysis by baker's yeast (Saccharomyces cerevisiae) generated ATP which was used to produce D: -glyceraldehyde 3-phosphate production from glucose via fructose 1,6-diphosphate. The D: -glyceraldehyde 3-phosphate produced was transformed to 2'-deoxyribonucleoside via 2-deoxyribose 5-phosphate and then 2-deoxyribose 1-phosphate in the presence of acetaldehyde and a nucleobase by deoxyriboaldolase, phosphopentomutase expressed in Escherichia coli, and a commercial nucleoside phosphorylase. About 33 mM 2'-deoxyinosine was produced from 600 mM glucose, 333 mM acetaldehyde and 100 mM adenine in 24 h. 2'-Deoxyinosine was produced from adenine due to the adenosine deaminase activity of E. coli transformants.

  19. Determination of trace amounts of formaldehyde in acetone.

    PubMed

    Huang, X H Hilda; Ip, H S Simon; Yu, Jian Zhen

    2007-12-01

    A method to quantify sub-ppm levels of formaldehyde in acetone has been developed and it is reported here. In this method, the different reactivities and stabilities of sulfite with formaldehyde and acetone are used to separate the two carbonyl compounds. Sulfite reacts with formaldehyde to form hydroxymethanesulfonate (HMS), the non-volatile and stable nature of which allows its separation from bulk acetone solvent. The resulting HMS is then converted back to formaldehyde under basic conditions, and formaldehyde is derivatized with 2,4-dinitrophenylhydrazine (DNPH) and quantified in its DNP hydrazone form using high-performance liquid chromatography-UV detection. The method detection limit at the 99% confidence level was 0.051 mg L(-1). A batch of samples can be processed within 4 h. The method has been applied to quantify the amount of formaldehyde in an analytical-grade acetone and in a commercial nail polish remover and the level of formaldehyde was found to be 0.175 and 0.184 mg L(-1), respectively. PMID:17996534

  20. NASOPHARYNGEAL CONCENTRATIONS IN THE HUMAN VOLUNTEER BREATHING ACETONE

    EPA Science Inventory

    In an effort to examine the absorption of a common chemical into the nasopharyngeal region in humans, a 57 year old male volunteer inhaled uniformly labeled 13C-acetone at 1.4 ppm for 30 min while performing different breathing maneuvers; nose inhale, nose exhale (NINE); mouth ...

  1. Genetic-epidemiological evidence for the role of acetaldehyde in cancers related to alcohol drinking.

    PubMed

    Eriksson, C J Peter

    2015-01-01

    Alcohol drinking increases the risk for a number of cancers. Currently, the highest risk (Group 1) concerns oral cavity, pharynx, larynx, esophagus, liver, colorectum, and female breast, as assessed by the International Agency for Research on Cancer (IARC). Alcohol and other beverage constituents, their metabolic effects, and alcohol-related unhealthy lifestyles have been suggested as etiological factors. The aim of the present survey is to evaluate the carcinogenic role of acetaldehyde in alcohol-related cancers, with special emphasis on the genetic-epidemiological evidence. Acetaldehyde, as a constituent of alcoholic beverages, and microbial and endogenous alcohol oxidation well explain why alcohol-related cancers primarily occur in the digestive tracts and other tissues with active alcohol and acetaldehyde metabolism. Genetic-epidemiological research has brought compelling evidence for the causality of acetaldehyde in alcohol-related cancers. Thus, IARC recently categorized alcohol-drinking-related acetaldehyde to Group 1 for head and neck and esophageal cancers. This is probably just the tip of the iceberg, since more recent epidemiological studies have also shown significant positive associations between the aldehyde dehydrogenase ALDH2 (rs671)*2 allele (encoding inactive enzyme causing high acetaldehyde elevations) and gastric, colorectal, lung, and hepatocellular cancers. However, a number of the current studies lack the appropriate matching or stratification of alcohol drinking in the case-control comparisons, which has led to erroneous interpretations of the data. Future studies should consider these aspects more thoroughly. The polymorphism phenotypes (flushing and nausea) may provide valuable tools for future successful health education in the prevention of alcohol-drinking-related cancers.

  2. In vitro expression of Candida albicans alcohol dehydrogenase genes involved in acetaldehyde metabolism.

    PubMed

    Bakri, M M; Rich, A M; Cannon, R D; Holmes, A R

    2015-02-01

    Alcohol consumption is a risk factor for oral cancer, possibly via its conversion to acetaldehyde, a known carcinogen. The oral commensal yeast Candida albicans may be one of the agents responsible for this conversion intra-orally. The alcohol dehydrogenase (Adh) family of enzymes are involved in acetaldehyde metabolism in yeast but, for C. albicans it is not known which family member is responsible for the conversion of ethanol to acetaldehyde. In this study we determined the expression of mRNAs from three C. albicans Adh genes (CaADH1, CaADH2 and CaCDH3) for cells grown in different culture media at different growth phases by Northern blot analysis and quantitative reverse transcription polymerase chain reaction. CaADH1 was constitutively expressed under all growth conditions but there was differential expression of CaADH2. CaADH3 expression was not detected. To investigate whether CaAdh1p or CaAdh2p can contribute to alcohol catabolism in C. albicans, each gene from the reference strain C. albicans SC5314 was expressed in Saccharomyces cerevisiae. Cell extracts from an CaAdh1p-expressing S. cerevisiae recombinant, but not an CaAdh2p-expressing recombinant, or an empty vector control strain, possessed ethanol-utilizing Adh activity above endogenous S. cerevisiae activity. Furthermore, expression of C. albicans Adh1p in a recombinant S. cerevisiae strain in which the endogenous ScADH2 gene (known to convert ethanol to acetaldehyde in this yeast) had been deleted, conferred an NAD-dependent ethanol-utilizing, and so acetaldehyde-producing, Adh activity. We conclude that CaAdh1p is the enzyme responsible for ethanol use under in vitro growth conditions, and may contribute to the intra-oral production of acetaldehyde.

  3. EPAC activation inhibits acetaldehyde-induced activation and proliferation of hepatic stellate cell via Rap1.

    PubMed

    Yang, Yan; Yang, Feng; Wu, Xiaojuan; Lv, Xiongwen; Li, Jun

    2016-05-01

    Hepatic stellate cells (HSCs) activation represents an essential event during alcoholic liver fibrosis (ALF). Previous studies have demonstrated that the rat HSCs could be significantly activated after exposure to 200 μmol/L acetaldehyde for 48 h, and the cAMP/PKA signaling pathways were also dramatically upregulated in activated HSCs isolated from alcoholic fibrotic rat liver. Exchange protein activated by cAMP (EPAC) is a family of guanine nucleotide exchange factors (GEFs) for the small Ras-like GTPases Rap, and is being considered as a vital mediator of cAMP signaling in parallel with the principal cAMP target protein kinase A (PKA). Our data showed that both cAMP/PKA and cAMP/EPAC signaling pathways were involved in acetaldehyde-induced HSCs. Acetaldehyde could reduce the expression of EPAC1 while enhancing the expression of EPAC2. The cAMP analog Me-cAMP, which stimulates the EPAC/Rap1 pathway, could significantly decrease the proliferation and collagen synthesis of acetaldehyde-induced HSCs. Furthermore, depletion of EPAC2, but not EPAC1, prevented the activation of HSC measured as the production of α-SMA and collagen type I and III, indicating that EPAC1 appears to have protective effects on acetaldehyde-induced HSCs. Curiously, activation of PKA or EPAC perhaps has opposite effects on the synthesis of collagen and α-SMA: EPAC activation by Me-cAMP increased the levels of GTP-bound (activated) Rap1 while PKA activation by Phe-cAMP had no significant effects on such binding. These results suggested that EPAC activation could inhibit the activation and proliferation of acetaldehyde-induced HSCs via Rap1. PMID:26854595

  4. Gene cloning, expression, and characterization of a novel acetaldehyde dehydrogenase from Issatchenkia terricola strain XJ-2.

    PubMed

    Yao, Zhengying; Zhang, Chong; Lu, Fengxia; Bie, Xiaomei; Lu, Zhaoxin

    2012-03-01

    Acetaldehyde is a known mutagen and carcinogen. Active aldehyde dehydrogenase (ALDH) represents an important mechanism for acetaldehyde detoxification. A yeast strain XJ-2 isolated from grape samples was found to produce acetaldehyde dehydrogenase with a high activity of 2.28 U/mg and identified as Issatchenkia terricola. The enzyme activity was validated by oxidizing acetaldehyde to acetate with NAD(+) as coenzyme based on the headspace gas chromatography analysis. A novel acetaldehyde dehydrogenase gene (ist-ALD) was cloned by combining SiteFinding-PCR and self-formed adaptor PCR. The ist-ALD gene comprised an open reading frame of 1,578 bp and encoded a protein of 525 amino acids. The predicted protein of ist-ALD showed the highest identity (73%) to ALDH from Pichia angusta. The ist-ALD gene was expressed in Escherichia coli, and the gene product (ist-ALDH) presented a productivity of 442.3 U/mL cells. The purified ist-ALDH was a homotetramer of 232 kDa consisting of 57 kDa-subunit according to the SDS-PAGE and native PAGE analysis. Ist-ALDH exhibited the optimal activity at pH 9.0 and 40°C, respectively. The activity of ist-ALDH was enhanced by K(+), NH4(+), dithiothreitol, and 2-mercaptoethanol but strongly inhibited by Ag(+), Hg(2+), Cu(2+), and phenylmethyl sulfonylfluoride. In the presence of NAD(+), ist-ALDH could oxidize many aliphatic, aromatic, and heterocyclic aldehydes, preferably acetaldehyde. Kinetic study revealed that ist-ALDH had a k (cat) value of 27.71/s and a k (cat)/K (m) value of 26.80 × 10(3)/(mol s) on acetaldehyde, demonstrating ist-ALDH, a catalytically active enzyme by comparing with other ALDHs. These studies indicated that ist-ALDH was a potential enzymatic product for acetaldehyde detoxification. PMID:21858493

  5. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    NASA Astrophysics Data System (ADS)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  6. A fully integrated standalone portable cavity ringdown breath acetone analyzer.

    PubMed

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  7. Acetaldehyde Induces Cytotoxicity of SH-SY5Y Cells via Inhibition of Akt Activation and Induction of Oxidative Stress

    PubMed Central

    Yan, Tingting; Zhao, Yan; Zhang, Xia

    2016-01-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. It has been shown that heavy drinking is associated with an earlier onset of neurodegenerative diseases such as Alzheimer's disease. Acetaldehyde, the most toxic metabolite of ethanol, is speculated to mediate the brain tissue damage and cognitive dysfunction induced by the chronic excessive consumption of alcohol. However, the exact mechanisms by which acetaldehyde induces neurotoxicity are not totally understood. In this study, we investigated the cytotoxic effects of acetaldehyde in SH-SY5Y cells and found that acetaldehyde induced apoptosis of SH-SY5Y cells by downregulating the expression of antiapoptotic Bcl-2 and Bcl-xL and upregulating the expression of proapoptotic Bax. Acetaldehyde treatment led to a significant decrease in the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). In addition, acetaldehyde induced the activation of p38 mitogen-activated protein kinase (MAPK) while inhibiting the activation of extracellular signal-regulated kinases (ERKs, p44/p42MAPK). Meanwhile, acetaldehyde treatment caused an increase in the production of reactive oxygen species and elevated the oxidative stress in SH-SY5Y cells. Therefore, acetaldehyde induces cytotoxicity of SH-SY5Y cells via promotion of apoptotic signaling, inhibition of cell survival pathway, and induction of oxidative stress. PMID:26649137

  8. Acetaldehyde Induces Cytotoxicity of SH-SY5Y Cells via Inhibition of Akt Activation and Induction of Oxidative Stress.

    PubMed

    Yan, Tingting; Zhao, Yan; Zhang, Xia

    2016-01-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. It has been shown that heavy drinking is associated with an earlier onset of neurodegenerative diseases such as Alzheimer's disease. Acetaldehyde, the most toxic metabolite of ethanol, is speculated to mediate the brain tissue damage and cognitive dysfunction induced by the chronic excessive consumption of alcohol. However, the exact mechanisms by which acetaldehyde induces neurotoxicity are not totally understood. In this study, we investigated the cytotoxic effects of acetaldehyde in SH-SY5Y cells and found that acetaldehyde induced apoptosis of SH-SY5Y cells by downregulating the expression of antiapoptotic Bcl-2 and Bcl-xL and upregulating the expression of proapoptotic Bax. Acetaldehyde treatment led to a significant decrease in the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). In addition, acetaldehyde induced the activation of p38 mitogen-activated protein kinase (MAPK) while inhibiting the activation of extracellular signal-regulated kinases (ERKs, p44/p42MAPK). Meanwhile, acetaldehyde treatment caused an increase in the production of reactive oxygen species and elevated the oxidative stress in SH-SY5Y cells. Therefore, acetaldehyde induces cytotoxicity of SH-SY5Y cells via promotion of apoptotic signaling, inhibition of cell survival pathway, and induction of oxidative stress.

  9. Photo-catalytic oxidation of acetone on a TiO2 powder: An in situ FTIR investigation

    SciTech Connect

    Szanyi, János; Kwak, Ja Hun

    2015-09-01

    In situ transmission infrared spectroscopy was used to investigate the photo-oxidation of acetone on a commercial, oxidized TiO2 (P25) powder catalyst under UV irradiation at ambient temperature, in the absence and presence of gas phase O2. The photochemistry of a number of organic molecules (1-butanone, methanol and acetic acid,) under the same conditions was also studied in order to identify reaction intermediates and products formed in the photo-oxidation of acetone. Under anaerobic conditions (in the absence of gas phase oxygen) limited extent of photo-oxidation of acetone took place on the oxidized TiO2 sample. In the presence of O2 in the gas phase, however, acetone was completely converted to acetates and formates, and ultimately CO2. The initial step in the sequence of photo-induced reactions is the ejection of a methyl radical, resulting in the formation of surface acetates (from the acetyl group) and formates (from the methyl radicals). Acetate ions are also converted to formates, that, in turn, photo-oxidized to CO2. Under the experimental conditions applied the accumulation of carbonates and bicarbonates were observed on the TiO2 surface as the photo-oxidation of acetone proceeded (this was also observed during the course of photo-oxidation of all the other organics studied here). When the initial radical ejection step produced hydrocarbons containing more than one C atoms (as in the case in 2-butanone and mesytil oxide), the formation of aldehydes on the catalyst surface was also observed as a result of secondary reactions. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy. JHK also acknowledges the support of this work by the 2014 Research Fund of UNIST (Ulsan National Institute of Science and Technology, Ulsan, Korea). The authors thank M

  10. Flavor threshold for acetaldehyde in milk, chocolate milk, and spring water using solid phase microextraction gas chromatography for quantification.

    PubMed

    van Aardt, M; Duncan, S E; Bourne, D; Marcy, J E; Long, T E; Hackney, C R; Heisey, C

    2001-03-01

    The detection threshold of acetaldehyde was determined on whole, lowfat, and nonfat milks, chocolate-flavored milk, and spring water. Knowledge of the acetaldehyde threshold is important because acetaldehyde forms in milk during storage as a result of light oxidation. It is also a degradation product of poly(ethylene terephthalate) during melt processing, a relatively new packaging choice for milk and water. There was no significant difference in the acetaldehyde threshold in milk of various fat contents, with thresholds ranging from 3939 to 4040 ppb. Chocolate-flavored milk and spring water showed thresholds of 10048 and 167 ppb, respectively, which compares favorably with previous studies. Solid phase microextraction (SPME) was verified as an effective method for the recovery of acetaldehyde in all media with detection levels as low as 200 and 20 ppb in milk and water, respectively, when using a polydimethyl siloxane/Carboxen SPME fiber in static headspace at 45 degrees C for 15 min.

  11. Measurement of the diffusion coefficient of acetone in succinonitrile at its melting point

    NASA Technical Reports Server (NTRS)

    Chopra, M. A.; Glicksman, M. E.; Singh, N. B.

    1988-01-01

    The diffusion coefficient of acetone in liquid succinonitrile at 331.1 K was determined using the method of McBain and Dawson (1935). Only dilute mixtures of SCN-acetone were studied. The interdiffusion constant was determined to be 0.0000127 sq cm/s and was essentially independent of the acetone concentration over the range investigated (0.5 to 18 mol pct acetone).

  12. Methanol simplifies gas processing

    SciTech Connect

    Minkkinen, A.; Jonchere, J.P.

    1997-12-31

    Recent development of a simple single solvent technology goes far to meet the complete gas processing needs. The use of methanol, as practiced in the IPFEXOL process, where it is used not only as a hydrate inhibitor and antifreeze agent but as an acid gas extraction solvent makes the complete gas processing scheme simple and probably the most cost effective as well. This paper presents several gas processing applications where water, hydrocarbon liquids and acid gases are removed from natural wellhead production gases. Water and hydrocarbon liquids removal is achieved to the extent necessary to make a pipeline transportable gas or meet downstream cryogenic processing demands. These are illustrated with recent applications of the IFPEX-1 process successfully operating today in North America and the Far East. A recent North Sea offshore project is highlighted showing the particular advantages in offshore applications. For the removal of water and hydrocarbon liquids together with a substantial quantity of not only CO{sub 2} but H{sub 2}S, the most complete methanol use scheme is presented. This is illustrated with the development of an advanced version of the IFPEX-2 process containing some innovative but simple equipment concepts which yields high pressure dry acid gases for reinjection or a high quality acid gas destined to Claus type sulfur recovery.

  13. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ACN. Both the impinger and cartridge samples must be analyzed by HPLC without additional sample... liquid chromatograph (HPLC). Standards consisting of the hydrazone derivative of formaldehyde and acetaldehyde are used to determine the response, repeatability, and limit of quantitation of the HPLC...

  14. Modeling the IR Spectra of Acetaldehyde from a New Vibrational Configuration Interaction Method

    SciTech Connect

    Begue, Didier; Pouchan, Claude

    2007-12-26

    In this paper we present a new vibrational configuration interaction method known as a parallel vibrational multiple window configuration interaction P lowbar VMWCI which generates several VCI matrices and enables the variational treatment of medium size molecular systems. Application to acetaldehyde gives a new interpretation of the MIR experimental data.

  15. Regional Sources of Atmospheric Formaldehyde and Acetaldehyde, and Implications for Atmospheric Modeling

    EPA Science Inventory

    Formaldehyde and acetaldehyde concentrations over the Eastern half of the United States are simulated with a 3-D air quality model to identify the most important chemical precursors under January and July conditions. We find that both aldehydes primarily result from photochemical...

  16. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cartridges or impingers filled with solutions of DNPH in acetonitrile (ACN) as described in §§ 86.109 and 86... for impingers containing 20 ml of absorbing solution (using more absorbing solution in the impinger... chosen for acetaldehyde and formaldehyde. (e) Other sampling and analytical techniques will be allowed...

  17. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... cartridges or impingers filled with solutions of DNPH in acetonitrile (ACN) as described in §§ 86.109 and 86... for impingers containing 20 ml of absorbing solution (using more absorbing solution in the impinger... chosen for acetaldehyde and formaldehyde. (e) Other sampling and analytical techniques will be allowed...

  18. [Effect of ethanol and acetaldehyde on the positive reinforcement structures in rats].

    PubMed

    Burov, Iu V; Borisenko, S A

    1979-01-01

    An activating action of low doses of ethanol and depressant action of acetaldehyde on the hypothalamic and septal structures of positive reinforcement was established in rat experiments using the method of self-stimulation. The relationship between ethanol activating action on these structures and its increased consumption in the conditions of free choice between ethanol and water was demonstrated.

  19. 40 CFR 721.10662 - Acetaldehyde, substituted-, reaction products with 2-butyne-1, 4-diol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acetaldehyde, substituted-, reaction...-, reaction products with 2-butyne-1, 4-diol (generic). (a) Chemical substance and significant new uses...-, reaction products with 2-butyne-1, 4-diol (PMN P-11-204) is subject to reporting under this section for...

  20. 40 CFR 721.10662 - Acetaldehyde, substituted-, reaction products with 2-butyne-1, 4-diol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acetaldehyde, substituted-, reaction...-, reaction products with 2-butyne-1, 4-diol (generic). (a) Chemical substance and significant new uses...-, reaction products with 2-butyne-1, 4-diol (PMN P-11-204) is subject to reporting under this section for...

  1. [Effect of pyrazole on the activity of acetaldehyde-producing enzymes in the liver].

    PubMed

    Gerashchenko, D Iu; Gorenshteĭn, B I; Pyzhik, T N; Ostrovskiĭ, Iu M

    1993-01-01

    Influence of pyrazole on the endogenous ethanol level and activities of acetaldehyde-producing enzymes was investigated. Drastic enhancement of the endogenous ethanol level in the blood and tissues was accompanied by an insignificant increase of phosphoethanolamine lyase activity, while activity of threonine aldolase and pyruvate dehydrogenase was unchanged.

  2. Development of industrial brewing yeast with low acetaldehyde production and improved flavor stability.

    PubMed

    Wang, Jinjing; Shen, Nan; Yin, Hua; Liu, Chunfeng; Li, Yongxian; Li, Qi

    2013-02-01

    Higher acetaldehyde concentration in beer is one of the main concerns of current beer industry in China. Acetaldehyde is always synthesized during beer brewing by the metabolism of yeast. Here, using ethanol as the sole carbon source and 4-methylpyrazole as the selection marker, we constructed a new mutant strain with lower acetaldehyde production and improved ethanol tolerance via traditional mutagenesis strategy. European Brewery Convention tube fermentation tests comparing the fermentation broths of mutant strain and industrial brewing strain showed that the acetaldehyde concentration of mutant strain was 81.67 % lower, whereas its resistant staling value was 1.0-fold higher. Owing to the mutation, the alcohol dehydrogenase activity of the mutant strain decreased to about 30 % of the wild-type strain. In the meantime, the fermentation performance of the newly screened strain has little difference compared with the wild-type strain, and there are no safety problems regarding the industrial usage of the mutant strain. Therefore, we suggest that the newly screened strain could be directly applied to brewing industry.

  3. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ACN. Both the impinger and cartridge samples must be analyzed by HPLC without additional sample... liquid chromatograph (HPLC). Standards consisting of the hydrazone derivative of formaldehyde and acetaldehyde are used to determine the response, repeatability, and limit of quantitation of the HPLC...

  4. BIOGENIC SOURCES OF FORMALDEHYDE AND ACETALDEHYDE DURING SUMMER AND WINTER CONDITIONS

    EPA Science Inventory

    Photochemical modeling estimated contributions to ambient concentrations of formaldehyde and acetaldehyde from biogenic emissions over the continental United States during January 2001 (Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstract A52B-0117). Results showed that maximum co...

  5. Involvement of the endogenous opioid system in the psychopharmacological actions of ethanol: the role of acetaldehyde

    PubMed Central

    Font, Laura; Luján, Miguel Á.; Pastor, Raúl

    2013-01-01

    Significant evidence implicates the endogenous opioid system (EOS) (opioid peptides and receptors) in the mechanisms underlying the psychopharmacological effects of ethanol. Ethanol modulates opioidergic signaling and function at different levels, including biosynthesis, release, and degradation of opioid peptides, as well as binding of endogenous ligands to opioid receptors. The role of β-endorphin and µ-opioid receptors (OR) have been suggested to be of particular importance in mediating some of the behavioral effects of ethanol, including psychomotor stimulation and sensitization, consumption and conditioned place preference (CPP). Ethanol increases the release of β-endorphin from the hypothalamic arcuate nucleus (NArc), which can modulate activity of other neurotransmitter systems such as mesolimbic dopamine (DA). The precise mechanism by which ethanol induces a release of β-endorphin, thereby inducing behavioral responses, remains to be elucidated. The present review summarizes accumulative data suggesting that the first metabolite of ethanol, the psychoactive compound acetaldehyde, could participate in such mechanism. Two lines of research involving acetaldehyde are reviewed: (1) implications of the formation of acetaldehyde in brain areas such as the NArc, with high expression of ethanol metabolizing enzymes and presence of cell bodies of endorphinic neurons and (2) the formation of condensation products between DA and acetaldehyde such as salsolinol, which exerts its actions via OR. PMID:23914161

  6. Metadoxine prevents damage produced by ethanol and acetaldehyde in hepatocyte and hepatic stellate cells in culture.

    PubMed

    Gutiérrez-Ruiz, M C; Bucio, L; Correa, A; Souza, V; Hernández, E; Gómez-Quiroz, L E; Kershenobich, D

    2001-11-01

    Metadoxine (pyridoxine-pyrrolidone carboxylate) has been reported to improve liver function tests in alcoholic patients. In the present work we have investigated the effect of metadoxine on some parameters of cellular damage in hepatocytes and hepatic stellate cells in culture treated with ethanol and acetaldehyde. HepG2 and CFSC-2G cells were treated with 50 mM ethanol or 175 microM acetaldehyde as initial concentration in the presence or absence of 10 microg ml(-1) of metadoxine. Twenty-four hours later reduced and oxidized glutathione content, lipid peroxidation damage, collagen secretion and IL-6, IL-8 and TNF- alpha secretion were determined. Our results suggest that metadoxine prevents glutathione depletion and the increase in lipid peroxidation damage caused by ethanol and acetaldehyde in HepG2 cells. In hepatic stellate cells, metadoxine prevents the increase in collagen and attenuated TNF- alpha secretion caused by acetaldehyde. Thus, metadoxine could be useful in preventing the damage produced in early stages of alcoholic liver disease as it prevents the redox imbalance of the hepatocytes and prevents TNF- alpha induction, one of the earliest events in hepatic damage. PMID:11712874

  7. Acetaldehyde formation in submerged cultures of non-film-forming species of Saccharomyces.

    PubMed

    OUGH, C S

    1961-07-01

    Three different yeasts of the species Saccharomyces cerevisiae ferment ethyl alcohol to acetaldehyde aerobically and produce "flor" character in a wine medium with submerged culture techniques. Three pounds per square inch gauge (psig) of oxygen instead of 15 psig of air permitted fermentations to proceed, though slightly slower in the series tested, and reaching slightly lower total aldehydes.

  8. Phytochemical composition, GC-MS analysis, in vitro antioxidant and antibacterial potential of clove flower bud (Eugenia caryophyllus) methanolic extract.

    PubMed

    Hemalatha, R; Nivetha, P; Mohanapriya, C; Sharmila, G; Muthukumaran, C; Gopinath, M

    2016-02-01

    Plant derived pharmacologically active compounds have gained importance in food and pharmaceutical industries. The aim of the present study is to identify and study the antioxidant, antimicrobial properties of the phytochemicals present in the crude extract of Eugenia caryophyllus flower buds. The antioxidant activity of the methanol, acetone and chloroform extract was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The methanol extract showed better radical scavenging activity than other selected solvents. Preliminary screening of phytochemicals was carried out in methanol extract and total phenol content was found high. Antibacterial activity was determined by well diffusion assay and methanol extract was found effective against Klebsiella pneumonia. FTIR and GC-MS results indicate the presence of aromatic compounds and major constituents were found to be eugenol and eugenyl acetate. Results of this study implied that Eugenia caryophyllus flower bud extract could be considered as health nutriments in food and pharmaceutical industries. PMID:27162398

  9. Economic evaluation of the acetone-butane fermentation

    SciTech Connect

    Lenz, T.G.; Moreira, A.R.

    1980-01-01

    The economics of producing acetone as 1-butanol via fermentation have been examined for a 45 x 1 kg of solvents/year plant. For a molasses substrate the total annual production costs were approximately $39 million vs. a total annual income of $36 million, with approximatley $20 million total required capital. Molasses cost of approximately $24.4 million/year was critical to these economics. Liquid whey was next evaluated as an alternative feed. Whey feed saved approximately 11 million dollars annually in feed costs and yielded approximately 8 million net additional annual revenues from protein sale. The primary differences gave an annual gross profit of approximately $15 million for the whey case and resulted in a discounted cash flow rate return of 29%. Waste-based acetone-butanol production via fermentation deserves further attention in view of the attractive whey-based economics and the excellent potential of butanol as a fuel extender, especially for diesohol blending.

  10. Effects of acetone on methyl ethyl ketone peroxide runaway reaction.

    PubMed

    Lin, Yan-Fu; Tseng, Jo-Ming; Wu, Tsung-Chih; Shu, Chi-Min

    2008-05-30

    Runaway reactions by methyl ethyl ketone peroxide (MEKPO) are an important issue in Asia, due to its unstable structure and extensive heat release during upset situations. This study employed differential scanning calorimetry (DSC) to draw the experimental data for MEKPO 31 mass% and with acetone 99 mass% on three types of heating rate of 2, 4, and 10 degrees C/min; the kinetic and safety parameters were then evaluated via curve fitting. Through the reproducible tests in each condition, the results show that acetone is not a contaminant, because it could increase the activation energy (Ea) and onset temperature (To) when combined with MEKPO, which differs from the hazard information of the material safety data sheet (MSDS).

  11. Ethanol, acetone and ammonia gas room temperature operated sensor

    NASA Astrophysics Data System (ADS)

    Singh, Iqbal; Bedi, R. K.

    2013-06-01

    CuO nanocrystalline thick films were fabricated from powder synthesized by a sol-gel auto combustion route at different pH value of the precursor solution. The gas sensing response of thick film samples towards ethanol, acetone and ammonia gases has been tested and response has been found to be higher for ammonia gas. The sensor recovers its original state after ammonia exposure.

  12. Self-Associating Behavior of Acetone in Liquid Krypton.

    PubMed

    De Beuckeleer, Liene I; Herrebout, Wouter A

    2016-02-18

    Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1).

  13. Self-Associating Behavior of Acetone in Liquid Krypton.

    PubMed

    De Beuckeleer, Liene I; Herrebout, Wouter A

    2016-02-18

    Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1). PMID:26805773

  14. Reverse osmosis application for butanol-acetone fermentation

    SciTech Connect

    Garcia, A.; Iannotti, E.L.; Fischer, J.R.

    1984-01-01

    The problems of dilute solvent concentration in butanol-acetone fermentation can be solved by using reverse osmosis to dewater the fermentation liquor. Polyamide membranes exhibited butanol rejection rates as high as 85%. Optimum rejection of butanol occurs at a pressure of approximately 5.5 to 6.5 MPa and hydraulic recoveries of 50-70%. Flux ranged from 0.5 to 1.8 l.

  15. Acetone oxidation using ozone on manganese oxide catalysts.

    PubMed

    Xi, Yan; Reed, Corey; Lee, Yong-Kul; Oyama, S Ted

    2005-09-22

    Supported manganese oxide catalysts were prepared by the impregnation of alumina foam blocks washcoated with alumina and silica. The manganese content based on the weight of the washcoats was 10 wt % calculated as MnO2. Fourier transform profiles of the Mn K-edge EXAFS spectra for these samples gave three distinctive peaks at 0.15, 0.25, and 0.32 nm and were close to the profiles of Mn3O4 and beta-MnO2. The number of surface active sites was determined through oxygen chemisorption measurements at a reduction temperature (Tred = 443 K) obtained from temperature-programmed reduction (TPR) experiments. Acetone catalytic oxidation was studied from room temperature to 573 K, and was found to be highly accelerated by the use of ozone on both catalysts with substantial reductions in the reaction temperature. The only carbon-containing product detected was CO2. The alumina-supported catalyst was found to be more active than the silica-supported catalyst in acetone and ozone conversion, with higher turnover frequencies (TOFs) for both reactions. The pressure drop through the foam was low and increased little (0.003 kPa/10 000 h(-1)) with space velocity. In situ steady-state Raman spectroscopy measurements during the acetone catalytic oxidation reaction showed the presence of an adsorbed acetone species with a C-H bond at 2930 cm(-1) and a peroxide species derived from ozone with an O-O bond at 890 cm(-1).

  16. Acetone Oxidation using Ozone on Manganese Oxide Catalysts

    SciTech Connect

    Xi,Y.; Reed, C.; Lee, Y.; Oyama, S.

    2005-01-01

    Supported manganese oxide catalysts were prepared by the impregnation of alumina foam blocks washcoated with alumina and silica. The manganese content based on the weight of the washcoats was 10 wt % calculated as MnO{sub 2}. Fourier transform profiles of the Mn K-edge EXAFS spectra for these samples gave three distinctive peaks at 0.15, 0.25, and 0.32 nm and were close to the profiles of Mn{sub 3}O{sub 4} and {beta}-MnO{sub 2}. The number of surface active sites was determined through oxygen chemisorption measurements at a reduction temperature (T{sub red} = 443 K) obtained from temperature-programmed reduction (TPR) experiments. Acetone catalytic oxidation was studied from room temperature to 573 K, and was found to be highly accelerated by the use of ozone on both catalysts with substantial reductions in the reaction temperature. The only carbon-containing product detected was CO{sub 2}. The alumina-supported catalyst was found to be more active than the silica-supported catalyst in acetone and ozone conversion, with higher turnover frequencies (TOFs) for both reactions. The pressure drop through the foam was low and increased little (0.003 kPa/10 000 h{sup -1}) with space velocity. In situ steady-state Raman spectroscopy measurements during the acetone catalytic oxidation reaction showed the presence of an adsorbed acetone species with a C-H bond at 2930 cm{sup -1} and a peroxide species derived from ozone with an O-O bond at 890 cm{sup -1}.

  17. Abundances of ethylene oxide and acetaldehyde in hot molecular cloud cores

    NASA Technical Reports Server (NTRS)

    Nummelin, A.; Dickens, J. E.; Bergman, P.; Hjalmarson, A.; Irvine, W. M.; Ikeda, M.; Ohishi, M.

    1998-01-01

    We have searched for millimetre-wave line emission from ethylene oxide (c-C2H4O) and its structural isomer acetaldehyde (CH3CHO) in 11 molecular clouds using SEST. Ethylene oxide and acetaldehyde were detected through multiple lines in the hot cores NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2. Acetaldehyde was also detected towards G10.47+0.03, G322.2+0.6, and Orion 3'N, and one ethylene oxide line was tentatively detected in G10.47+0.03. Column densities and rotational excitation temperatures were derived using a procedure which fits the observed line intensifies by finding the minimum chi 2-value. The resulting rotational excitation temperatures of ethylene oxide and acetaldehyde are in the range 16-38 K, indicating that these species are excited in the outer, cooler parts of the hot cores or that the excitation is significantly subthermal. For an assumed source size of 20", the deduced column densities are (0.6-1)x10(14) cm-2 for ethylene oxide and (2-5)x10(14) cm-2 for acetaldehyde. The fractional abundances with respect to H2 are X[c-C2H4O]=(2-6)xl0(-10), and X[CH3CHO]=(0.8-3)x10(-9). The ratio X[CH3CHO]/X[c-C2H4O] varies between 2.6 (NGC 6334F) and 8.5 (G327.3-0.6). We also detected and analysed multiple transitions of CH3OH, CH3OCH3, C2H5OH, and HCOOH. The chemical, and possibly evolutionary, states of NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2 seem to be very similar.

  18. Abundances of ethylene oxide and acetaldehyde in hot molecular cloud cores.

    PubMed

    Nummelin, A; Dickens, J E; Bergman, P; Hjalmarson, A; Irvine, W M; Ikeda, M; Ohishi, M

    1998-09-01

    We have searched for millimetre-wave line emission from ethylene oxide (c-C2H4O) and its structural isomer acetaldehyde (CH3CHO) in 11 molecular clouds using SEST. Ethylene oxide and acetaldehyde were detected through multiple lines in the hot cores NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2. Acetaldehyde was also detected towards G10.47+0.03, G322.2+0.6, and Orion 3'N, and one ethylene oxide line was tentatively detected in G10.47+0.03. Column densities and rotational excitation temperatures were derived using a procedure which fits the observed line intensifies by finding the minimum chi 2-value. The resulting rotational excitation temperatures of ethylene oxide and acetaldehyde are in the range 16-38 K, indicating that these species are excited in the outer, cooler parts of the hot cores or that the excitation is significantly subthermal. For an assumed source size of 20", the deduced column densities are (0.6-1)x10(14) cm-2 for ethylene oxide and (2-5)x10(14) cm-2 for acetaldehyde. The fractional abundances with respect to H2 are X[c-C2H4O]=(2-6)xl0(-10), and X[CH3CHO]=(0.8-3)x10(-9). The ratio X[CH3CHO]/X[c-C2H4O] varies between 2.6 (NGC 6334F) and 8.5 (G327.3-0.6). We also detected and analysed multiple transitions of CH3OH, CH3OCH3, C2H5OH, and HCOOH. The chemical, and possibly evolutionary, states of NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2 seem to be very similar.

  19. Indoor formaldehyde and acetaldehyde levels in the province of Bari, South Italy, and estimated health risk.

    PubMed

    Lovreglio, Piero; Carrus, Antonio; Iavicoli, Sergio; Drago, Ignazio; Persechino, Benedetta; Soleo, Leonardo

    2009-05-01

    Indoor and outdoor formaldehyde and acetaldehyde levels were assessed to characterize pollution in dwellings in the city and the Province of Bari, also taking into account seasonal variability, and to investigate health effects of aldehyde exposure on the general population. In 2007, passive environmental monitoring was performed, for 24 hours, in the kitchen of 59 dwellings, as well as outdoors for 27 of them. A questionnaire probing personal and home characteristics was administered to all 182 subjects habitually resident in the homes. During the period January-June 2008, formaldehyde and acetaldehyde levels were monitored monthly in 20 of the investigated dwellings inhabited only by non smokers. Indoor formaldehyde and acetaldehyde concentrations were significantly higher (16.0 +/- 8.0 and 10.7 +/- 8.8 microg m(-3)) than outdoor concentrations (4.4 +/- 1.7 and 3.4 +/- 2.0 microg m(-3)), showing a correlation between indoor levels of the two aldehydes (r = 0.41; p = 0.001). In dwellings inhabited only by non smokers, formaldehyde concentrations were higher in the presence of furniture bought new or restored less than one year before (p = 0.03). Formaldehyde and acetaldehyde levels were significantly higher in winter months than in spring-summer months (F = 2.86, p = 0.02; F = 5.39, p < 0.001) and seemed to be influenced by the time that kitchen windows were kept open. As regards the effects on human health, a low prevalence of allergic disease and no association between any irritant or allergic complaints and indoor levels of the two aldehydes was observed. In conclusion, the results showed low indoor and outdoor concentrations of formaldehyde and acetaldehyde, not generally posing a risk for human health.

  20. Pueraria lobata (Kudzu root) hangover remedies and acetaldehyde-associated neoplasm risk.

    PubMed

    McGregor, Neil R

    2007-11-01

    Recent introduction of several commercial Kudzu root (Pueraria lobata) containing hangover remedies has occurred in western countries. The available data is reviewed to assess if there are any potential concerns in relationship to the development of neoplasm if these products are used chronically. The herb Pueraria has two components that are used as traditional therapies; Pueraria lobata, the root based herb and Pueraria flos, the flower based herb. Both of these herbal components have different traditional claims and constituents. Pueraria flos, which enhances acetaldehyde removal, is the traditional hangover remedy. Conversely, Pueraria lobata is a known inhibitor of mitochondrial aldehyde dehydrogenase (ALDH2) and increases acetaldehyde. Pueraria lobata is being investigated for use as an aversion therapy for alcoholics due to these characteristics. Pueraria lobata is not a traditional hangover therapy yet has been accepted as the registered active component in many of these hangover products. The risk of development of acetaldehyde pathology, including neoplasms, is associated with genetic polymorphism with enhanced alcohol dehydrogenase (ADH) or reduced ALDH activity leading to increased acetaldehyde levels in the tissues. The chronic usage of Pueraria lobata at times of high ethanol consumption, such as in hangover remedies, may predispose subjects to an increased risk of acetaldehyde-related neoplasm and pathology. The guidelines for Disulfiram, an ALDH2 inhibitor, provide a set of guidelines for use with the herb Pueraria lobata. Pueraria lobata appears to be an inappropriate herb for use in herbal hangover remedies as it is an inhibitor of ALDH2. The recommendations for its use should be similar to those for the ALDH2 inhibitor, Disulfiram.

  1. Salivary acetaldehyde increase due to alcohol-containing mouthwash use: a risk factor for oral cancer.

    PubMed

    Lachenmeier, Dirk W; Gumbel-Mako, Szidönia; Sohnius, Eva-Maria; Keck-Wilhelm, Andrea; Kratz, Evamaria; Mildau, Gerd

    2009-08-01

    Increasing evidence suggests that acetaldehyde, the first and genotoxic metabolite of ethanol, mediates the carcinogenicity of alcoholic beverages. Ethanol is also contained in a number of ready-to-use mouthwashes typically between 5 and 27% vol. An increased risk of oral cancer has been discussed for users of such mouthwashes; however, epidemiological evidence had remained inconclusive. This study is the first to investigate acetaldehyde levels in saliva after use of alcohol-containing mouthwashes. Ready-to-use mouthwashes and mouthrinses (n = 13) were rinsed in the mouth by healthy, nonsmoking volunteers (n = 4) as intended by the manufacturers (20 ml for 30 sec). Saliva was collected at 0.5, 2, 5 and 10 min after mouthwash use and analyzed using headspace gas chromatography. The acetaldehyde content in the saliva was 41 +/- 15 microM, range 9-85 microM (0.5 min), 52 +/- 14 microM, range 11-105 microM (2 min), 32 +/- 7 microM, range 9-67 microM (5 min) and 15 +/- 7 microM, range 0-37 microM (10 min). The contents were significantly above endogenous levels and corresponding to concentrations normally found after alcoholic beverage consumption. A twice-daily use of alcohol-containing mouthwashes leads to a systemic acetaldehyde exposure of 0.26 microg/kg bodyweight/day on average, which corresponds to a lifetime cancer risk of 3E-6. The margin of exposure was calculated to be 217,604, which would be seen as a low public health concern. However, the local acetaldehyde contents in the saliva are reaching concentrations associated with DNA adduct formation and sister chromatid exchange in vitro, so that concerns for local carcinogenic effects in the oral cavity remain. PMID:19444911

  2. Effect of Coadsorbed Water on the Photodecomposition of Acetone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-06-10

    The influence of coadsorbed water on the photodecomposition of acetone on TiO2 was examined using temperature programmed desorption (TPD) and the rutile TiO2(110) surface as a model photocatalyst. Of the two major influences ascribed to water in the heterogeneous photocatalysis literature (promotion via OH radical supply and inhibition due to site blocking), only the negative influence of water was observed. As long as the total water and acetone coverage was maintained well below the first layer saturation coverage (‘1 ML’), little inhibition of acetone photodecomposition was observed. However, as the total water+acetone coverage exceeded 1 ML, acetone was preferentially displaced from the first layer to physisorbed states by water and the extent of acetone photodecomposition attenuated. The displacement originated from water compressing acetone into high coverage regions where increased acetone-acetone repulsions caused displacement from the first layer. The immediate product of acetone photodecomposition was adsorbed acetate, which occupies twice as many surface sites per molecule as compared to acetone. Since the acetate intermediate was more stable on the TiO2(110) surface than either water or acetone (as gauged by TPD) and since its photodecomposition rate was less than that of acetone, additional surface sites were not opened up during acetone photodecomposition for previously displaced acetone molecules to re-enter the first layer. Results in this study suggest that increased molecular-level repulsions between organic molecules brought about by increased water coverage are as influential in the inhibiting effect of water on photooxidation rates as are water-organic repulsions.

  3. Modeling of experimental treatment of acetaldehyde-laden air and phenol-containing water using corona discharge technique.

    PubMed

    Faungnawakij, Kajornsak; Sano, Noriaki; Charinpanitkul, Tawatchai; Tanthapanichakoon, Wiwut

    2006-03-01

    Acetaldehyde-laden air and phenol-contaminated water were experimentally treated using corona discharge reactions and gas absorption in a single water-film column. Mathematical modeling of the combined treatment was developed in this work. Efficient removal of the gaseous acetaldehyde was achieved while the corona discharge reactions produced short-lived species such as O and O- as well as ozone. Direct contact of the radicals and ions with water was known to produce aqueous OH radical, which contributes to the decomposition of organic contaminants: phenol, absorbed acetaldehyde, and intermediate byproducts in the water. The influence of initial phenol concentration ranging from 15 to 50 mg L(-1) and that of influent acetaldehyde ranging from 0 to 200 ppm were experimentally investigated and used to build the math model. The maximum energetic efficiency of TOC, phenol, and acetaldehyde were obtained at 25.6 x 10(-9) mol carbon J(-1), 25.0 x 10(-9) mol phenol J(-1), and 2.0 x 10(-9) mol acetaldehyde J(-1), respectively. The predictions for the decomposition of acetaldehyde, phenol, and their intermediates were found to be in good agreement with the experimental results. PMID:16568779

  4. Formation of 2-propanol in condensed molecular films of acetaldehyde following electron impact ionisation-induced proton transfer*

    NASA Astrophysics Data System (ADS)

    Borrmann, Tobias; Swiderek, Petra

    2016-06-01

    Experimental studies on thin condensed layers of acetaldehyde have previously revealed that electron exposure at an energy above the ionisation threshold leads to formation of 2-propanol. However, the mechanism of this reaction remained unclear. Therefore, a computational approach is used to explore the electron-induced reactions of acetaldehyde yielding 2-propanol. Starting from hydrogen-bonded dimers of acetaldehyde we show that the initial ionisation event triggers proton transfer between the two acetaldehyde moieties resulting in a hydrogen-bonded complex of a [OCCH3] radical and a protonated acetaldehyde cation. Given an excess energy of up to 0.75 eV and a favourable arrangement, a methyl radical released upon dissociation of the CC bond within the [OCCH3] radical can migrate to the carbonyl carbon of the protonated acetaldehyde cation. This produces a 2-propanol radical cation and CO. Neutral 2-propanol is then obtained by recombination with a second electron. A mechanism involving ionisation-driven proton transfer is thus proposed as pathway to the formation of 2-propanol during electron exposure of condensed layers of acetaldehyde.

  5. OTEC energy via methanol production

    SciTech Connect

    Avery, W.H.; Richards, D.; Niemeyer, W.G.; Shoemaker, J.D.

    1983-01-01

    The conceptual design of an 160 MW/sub e/ OTEC plantship has been documented; it is designed to produce 1000 tonne/day of fuel-grade methanol from coal slurry shipped to the plantship, using oxygen and hydrogen from the on-board electrolysis of water. Data and components are used that were derived by Brown and Root Development, Inc. (BARDI) in designing a barge-mounted plant to make methanol from natural gas for Litton Industries and in the design and construction of a coal-to-ammonia demonstration plant in operation at Muscle Shoals, Alabama, for the Tennessee Valley Authority (TVA). The OTEC-methanol plant design is based on the use of the Texaco gasifier and Lurgi synthesis units. The sale price of OTEC methanol delivered to port from this first-of-a-kind plant is estimated to be marginally competitive with methanol from other sources at current market prices.

  6. Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC.

    PubMed

    Oosterkamp, Margreet J; Boeren, Sjef; Atashgahi, Siavash; Plugge, Caroline M; Schaap, Peter J; Stams, Alfons J M

    2015-06-01

    Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In the proposed acetone degradation pathway, an acetone carboxylase converts acetone to acetoacetate, an AMP-dependent synthetase/ligase converts acetoacetate to acetoacetyl-CoA, and an acetyl-CoA acetyltransferase cleaves acetoacetyl-CoA to two acetyl-CoA. We also found a putative aldehyde dehydrogenase associated with acetone degradation. This enzyme functioned as a β-hydroxybutyrate dehydrogenase catalyzing the conversion of surplus acetoacetate to β-hydroxybutyrate that may be converted to the energy and carbon storage compound, poly-β-hydroxybutyrate. Accordingly, we confirmed the formation of poly-β-hydroxybutyrate in acetone-grown cells of strain BC. Our findings provide insight in nitrate-dependent acetone degradation that is activated by carboxylation of acetone. This will aid studies of similar pathways found in other microorganisms degrading acetone with nitrate or sulfate as electron acceptor.

  7. California methanol assessment. Volume 1: Summary report

    NASA Technical Reports Server (NTRS)

    Otoole, R.; Dutzi, E.; Gershman, R.; Heft, R.; Kalema, W.; Maynard, D.

    1983-01-01

    The near term methanol industry, the competitive environment, long term methanol market, the transition period, air quality impacts of methanol, roles of the public and private sectors are considered.

  8. Acetone Chemistry on Oxidized and Reduced TiO2(110)

    SciTech Connect

    Henderson, Michael A

    2004-12-09

    The chemistry of acetone on the oxidized and reduced surfaces of TiO2(110) was examined using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The reduced surface was prepared with about 7% oxygen vacancy sites by annealing in ultrahigh vacuum (UHV) at 850 K, and the oxidized surface was prepared by exposure of the reduced surface to molecular oxygen at 95 K followed by heating the surface to a variety of temperatures between 200 and 500 K. Acetone adsorbs molecularly on the reduced surface with no evidence for either decomposition or preferential binding at vacancy sites. Based on HREELS, the majority of acetone molecules adsorbed in an η¹ configuration at Ti⁴⁺ sites through interaction of lone pair electrons on the carbonyl oxygen atom. Repulsive acetone-acetone interactions shift the desorption peak from 345 K at low coverage to 175 K as the first layer saturates with a coverage of ~ 1 ML. In contrast, about 7% of the acetone adlayer decomposes when the surface is pretreated with molecular oxygen. Acetate is among the detected decomposition products, but only comprises about 1/3rd of the amount of acetone decomposed and its yield depends on the temperature at which the O₂ exposed surface was preheated to prior to acetone adsorption. Aside from the small level of irreversible decomposition, about 0.25 ML of acetone is stabilized to 375 K by coadsorbed oxygen. These acetone species exhibit an HREELS spectrum unlike that of η¹-acetone or of any other species proposed to exist from the interaction of acetone with TiO₂ powders. Based on the presence of extensive ¹⁶O/¹⁸O exchange between acetone and coadsorbed oxygen in the 375 K acetone TPD state, it is proposed that a polymeric form of acetone forms on the TiO₂(110) surface through nucleophilic attack of oxygen on the carbonyl carbon atom of acetone, and is propagated to neighboring η¹-acetone molecules. This process is initiated

  9. A shock tube and theory study of the dissociation of acetone and subsequent recombination of methyl radicals.

    SciTech Connect

    Saxena, A.; Kiefer, J. H.; Klippenstein, S. J.; Chemical Sciences and Engineering Division; Univ. of llinois at Chicago

    2009-01-01

    The dissociation of acetone: CH{sub 3}C{double_bond}OCH{sub 3} {yields} CH{sub 3}C{double_bond}O + CH{sub 3}, quickly followed by CH{sub 3}CO {yields} CH{sub 3} + CO, has been examined with Laser-Schlieren measurements in incident shock waves over 32-717 Torr and 1429-1936 K using 5% acetone dilute in krypton. A few very low pressure experiments ({approx}10 Torr) were used in a marginal effort to resolve the extremely fast vibrational relaxation of this molecule. This effort was partly motivated as a test for molecular, 'roaming methyl' reactions, and also as a source of methyl radicals to test the application of a recent high-temperature mechanism for ethane decomposition [J.H. Kiefer, S. Santhanam, N.K. Srinivasan, R.S. Tranter, S.J. Klippenstein, M.A. Oehlschlaeger, Proc. Combust. Inst. 30 (2005) 1129-1135] on the reverse methyl combination. The gradient profiles show strong initial positive gradients and following negative values fully consistent with methyl radical formation and its following recombination. Thus C-C fission is certainly a large part of the process and molecular channels cannot be responsible for more than 30% of the dissociation. Rates obtained for the C-C fission show strong falloff well fit by variable reaction coordinate transition state theory when combined with a master equation. The calculated barrier is 82.8 kcal/mol, the fitted <{Delta}E>{sub down} = 400 (T/298) cm{sup -1}, similar to what was found in a recent study of C-C fission in acetaldehyde, and the extrapolated k{sub {infinity}} = 10{sup 25.86} T{sup -2.72} exp(?87.7 (kcal/mol)/RT), which agrees with the literature rate for CH{sub 3} + CH{sub 3}CO. Large negative (exothermic) gradients appearing late from methyl combination are accurately fit in both time of onset and magnitude by the earlier ethane dissociation mechanism. The measured dissociation rates are in close accord with one earlier shock-tube study [K. Sato, Y. Hidaka, Combust. Flame 122 (2000) 291-311], but show much

  10. Insights into Acetone Photochemistry on Rutile TiO2(110). 1. Off-Normal CH3 Ejection from Acetone Diolate.

    SciTech Connect

    Petrik, Nikolay G.; Henderson, Michael A.; Kimmel, Gregory A.

    2015-06-04

    Thermal- and photon-stimulated reactions of acetone co-adsorbed with oxygen on rutile TiO2(110) surface are studied with infrared reflection-adsorption spectroscopy (IRAS) combined with temperature programmed desorption and angle-resolved photon stimulated desorption. IRAS results show that n2-acetone diolate ((CH3)2COO) is produced via thermally-activated reactions between the chemisorbed oxygen with co-adsorbed acetone. Formation of acetone diolate is also consistent with 18O / 16O isotopic exchange experiments. During UV irradiation at 30 K, CH3 radicals are ejected from the acetone diolate with a distribution that is peaked at .-. +- 66 degrees from the surface normal along the azimuth (i.e. perpendicular to the rows of bridging oxygen and Ti5c ions). This distribution is also consistent with the orientation of the C–CH3 bonds in the n2-acetone diolate on TiO2(110). The acetone diolate peaks disappear from the IRAS spectra after UV irradiation and new peaks are observed and associated with n2-acetate. The data presented here demonstrate direct signatures of the proposed earlier 2-step mechanism for acetone photooxidation on TiO2(110)

  11. Methanol crossover in direct methanol fuel cell systems.

    SciTech Connect

    Pivovar, B. S.; Bender, G.; Davey, J. R.; Zelenay, P.

    2003-01-01

    Direct methanol fuel cells (DMFCs) are currently being investigated for a number of different applications from several milliwatts to near kilowatt size scales (cell phones, laptops, auxiliary power units, etc .). Because methanol has a very high energy density, over 6000 W hr/kg, a DMFC can possibly have greatly extended lifetimes compared to the batteries, doesn't present the storage problems associated with hydrogen fuel cells and can possibly operate more efficiently and cleanly than internal combustion engines.

  12. Acetaldehyde as an intermediate in the electroreduction of carbon monoxide to ethanol on oxide-derived copper

    SciTech Connect

    Bertheussen, Erlend; Verdaguer-Casadevall, Arnau; Ravasio, Davide; Montoya, Joseph H.; Trimarco, Daniel B.; Roy, Claudie; Meier, Sebastian; Wendland, Jürgen; Nørskov, Jens K.; Stephens, Ifan E. L.; Chorkendorff, Ib

    2015-12-21

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at -0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at -0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results indicate an important step towards understanding the CO reduction mechanism on OD-Cu electrodes.

  13. Acetaldehyde as an intermediate in the electroreduction of carbon monoxide to ethanol on oxide-derived copper

    DOE PAGES

    Bertheussen, Erlend; Verdaguer-Casadevall, Arnau; Ravasio, Davide; Montoya, Joseph H.; Trimarco, Daniel B.; Roy, Claudie; Meier, Sebastian; Wendland, Jürgen; Nørskov, Jens K.; Stephens, Ifan E. L.; et al

    2015-12-21

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at -0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at -0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification.more » Our results indicate an important step towards understanding the CO reduction mechanism on OD-Cu electrodes.« less

  14. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide‐Derived Copper

    PubMed Central

    Bertheussen, Erlend; Verdaguer‐Casadevall, Arnau; Ravasio, Davide; Montoya, Joseph H.; Trimarco, Daniel B.; Roy, Claudie; Meier, Sebastian; Wendland, Jürgen; Nørskov, Jens K.

    2015-01-01

    Abstract Oxide‐derived copper (OD‐Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace‐gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD‐Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at −0.33 V (vs. RHE). We show that acetaldehyde forms at low steady‐state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results represent an important step towards understanding the CO reduction mechanism on OD‐Cu electrodes. PMID:26692282

  15. Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

    PubMed

    Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

    2014-11-26

    We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

  16. Molybdenum disulfide catalyzed tungsten oxide for on-chip acetone sensing

    NASA Astrophysics Data System (ADS)

    Li, Hong; Ahn, Sung Hoon; Park, Sangwook; Cai, Lili; Zhao, Jiheng; He, Jiajun; Zhou, Minjie; Park, Joonsuk; Zheng, Xiaolin

    2016-09-01

    Acetone sensing is critical for acetone leak detection and holds a great promise for the noninvasive diagnosis of diabetes. It is thus highly desirable to develop a wearable acetone sensor that has low cost, miniature size, sub-ppm detection limit, great selectivity, as well as low operating temperature. In this work, we demonstrate a cost-effective on-chip acetone sensor with excellent sensing performances at 200 °C using molybdenum disulfide (MoS2) catalyzed tungsten oxide (WO3). The WO3 based acetone sensors are first optimized via combined mesoscopic nanostructuring and silicon doping. Under the same testing conditions, our optimized mesoporous silicon doped WO3 [Si:WO3(meso)] sensor shows 2.5 times better sensitivity with ˜1000 times smaller active device area than the state-of-art WO3 based acetone sensor. Next, MoS2 is introduced to catalyze the acetone sensing reactions for Si:WO3(meso), which reduces the operating temperature by 100 °C while retaining its high sensing performances. Our miniaturized acetone sensor may serve as a wearable acetone detector for noninvasive diabetes monitoring or acetone leakage detection. Moreover, our work demonstrates that MoS2 can be a promising nonprecious catalyst for catalytic sensing applications.

  17. Acetone PLIF concentration measurements in a submerged round turbulent jet

    NASA Astrophysics Data System (ADS)

    Kravtsov, Z. D.; Chikishev, L. M.; Dulin, V. M.

    2016-10-01

    Transport of passive scalar in near-field of a submerged turbulent jet, was studied experimentally by using the planar laser-induced fluorescence technique. The jet issued from a round pipe with the inner diameter and length of 21 mm and 700 mm, respectively. Three cases of Reynolds numbers were studied: Re=3000, 6000, and 9000. Vapor of acetone, mixed to the jet flow, served as a passive fluorescent tracer. The paper describes data processing utilized to convert intensity of fluorescence images to the instantaneous concentration.

  18. Photocatalytic and thermal catalytic oxidation of acetaldehyde on Pt/TiO{sub 2}

    SciTech Connect

    Falconer, J.L.; Magrini-Bair, K.A.

    1998-10-01

    Low concentrations of acetaldehyde in air (60 ppm) were oxidized over TiO{sub 2} (Degussa P25) and 0.5% Pt/TiO{sub 2} catalysts from 24 to 200 C by photocatalytic and thermal catalytic reactions. On Pt/TiO{sub 2}, the contribution by photocatalytic oxidation (PCO) is a maximum at 140 C, where conversion is 2.8 times that at 24 C. Titania without Pt deactivates rapidly during PCO at elevated temperature due to a thermal catalytic reaction that takes place in parallel with PCO, but the addition of Pt dramatically slows deactivation. Apparently, Pt supplies spillover oxygen onto the TiO{sub 2}, and the oxygen oxidizes the acetaldehyde decomposition products in a dark reaction. Deactivated TiO{sub 2} without Pt was regenerated by PCO at room temperature. Seven distinct reactions (photocatalytic and thermal catalytic) are identified on Pt/TiO{sub 2}.

  19. Heterocyclic acetals from glycerol and acetaldehyde in Port wines: evolution with aging.

    PubMed

    da Silva Ferreira, Antonio Cesar; Barbe, Jean-Christophe; Bertrand, Alain

    2002-04-24

    In Port wine, isomers of glycerol and acetaldehyde acetals have been found at total contents ranging from 9.4 to 175.3 mg/L. During oxidative aging, the concentrations of the 5-hydroxy-2-methyl-1,3-dioxane and 4-hydroxymethyl-2-methyl-1,3-dioxolane isomers increased with time showing a linear correlation (r > 0.95). The flavor threshold for the mixture of the four isomers was evaluated in wine at 100 mg/L. Thus, it is expected that they contribute to "old Port wine" aroma in wines older than 30 years. Experiments with model solutions and wine clearly demonstrated that SO(2) combines with acetaldehyde and blocks the acetalization reaction. PMID:11958622

  20. Modification of carbonic anhydrase II with acetaldehyde, the first metabolite of ethanol, leads to decreased enzyme activity

    PubMed Central

    Bootorabi, Fatemeh; Jänis, Janne; Valjakka, Jarkko; Isoniemi, Sari; Vainiotalo, Pirjo; Vullo, Daniela; Supuran, Claudiu T; Waheed, Abdul; Sly, William S; Niemelä, Onni; Parkkila, Seppo

    2008-01-01

    Background Acetaldehyde, the first metabolite of ethanol, can generate covalent modifications of proteins and cellular constituents. However, functional consequences of such modification remain poorly defined. In the present study, we examined acetaldehyde reaction with human carbonic anhydrase (CA) isozyme II, which has several features that make it a suitable target protein: It is widely expressed, its enzymatic activity can be monitored, its structural and catalytic properties are known, and it contains 24 lysine residues, which are accessible sites for aldehyde reaction. Results Acetaldehyde treatment in the absence and presence of a reducing agent (NaBH3(CN)) caused shifts in the pI values of CA II. SDS-PAGE indicated a shift toward a slightly higher molecular mass. High-resolution mass spectra of CA II, measured with and without NaBH3(CN), indicated the presence of an unmodified protein, as expected. Mass spectra of CA II treated with acetaldehyde revealed a modified protein form (+26 Da), consistent with a "Schiff base" formation between acetaldehyde and one of the primary NH2 groups (e.g., in lysine side chain) in the protein structure. This reaction was highly specific, given the relative abundance of over 90% of the modified protein. In reducing conditions, each CA II molecule had reacted with 9–19 (14 on average) acetaldehyde molecules (+28 Da), consistent with further reduction of the "Schiff bases" to substituted amines (N-ethyllysine residues). The acetaldehyde-modified protein showed decreased CA enzymatic activity. Conclusion The acetaldehyde-derived modifications in CA II molecule may have physiological consequences in alcoholic patients. PMID:19036170

  1. Spectrophotometric study and potentiometric titration between sulfite and nitrite ions using acetaldehyde complex of nitroprusside as a carrier

    SciTech Connect

    Ahmed, Y.Z.; Abd-Elmottalb, M.

    1985-11-01

    A complex between sodium nitroprusside (NP) and acetaldehyde of 1:1 in aqueous solution of pH 10 has been prepared and used as an analytical reagent for the spectrophotometric determination of sulfite and nitrite ions. Nitrite ion can be titrated against sulfite ion and vise versa in equivalent amounts with high accuracy in the presence of the acetaldehyde complex of nitroprusside as a carrier using a potentiometric titration technique. 9 references, 3 figures, 2 tables.

  2. Zonal distribution of protein-acetaldehyde adducts in the liver of rats fed alcohol for long periods.

    PubMed

    Lin, R C; Zhou, F C; Fillenwarth, M J; Lumeng, L

    1993-10-01

    Acetaldehyde, a highly reactive intermediate of alcohol metabolism, has been shown to form adducts with liver proteins in rats fed alcohol for long periods. In this report, the zonal distribution of liver protein-acetaldehyde adducts that formed in vivo was studied by means of histoimmunostaining. Rats were pair-fed alcohol-containing and alcohol-free AIN'76 liquid diets for 2 or 11 wk before they were killed and subjected to whole body perfusion with paraformaldehyde. Each liver was cut into 60-microns-thick slices. Slices were first treated with 10% hydrogen peroxide to eliminate endogenous peroxidase activity. They were then incubated sequentially with rabbit antihemocyanin-acetaldehyde adduct, goat antirabbit serum IgG and rabbit peroxidase-antiperoxidase complex. The liver slices were stained with diaminobenzidine and counterstained with methylgreen. In the livers of rats fed alcohol for 2 wk, peroxidase activity was evident in the perivenous zone but not the periportal zone. No staining was obtained when the primary antibody had been preabsorbed with immobilized hemocyanin-acetaldehyde adduct or if the liver slices were incubated with the unimmunized rabbit IgG. Slight staining of the perivenous zone was seen in the livers of control rats, presumably because of minimal protein-acetaldehyde adduct formation emanating from endogenous acetaldehyde. When rats were fed alcohol for longer periods (e.g., 11 wk), protein-acetaldehyde adducts were still seen predominantly in the perivenous zone, but the distribution pattern was more diffuse than that observed in the livers of rats fed alcohol for only 2 wk. More liver cells produced protein-acetaldehyde adducts when rats were fed the alcohol-containing diet supplemented with cyanamide.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Methanol Oxidation on Pt3Sn(111) for Direct Methanol Fuel Cells: Methanol Decomposition.

    PubMed

    Lu, Xiaoqing; Deng, Zhigang; Guo, Chen; Wang, Weili; Wei, Shuxian; Ng, Siu-Pang; Chen, Xiangfeng; Ding, Ning; Guo, Wenyue; Wu, Chi-Man Lawrence

    2016-05-18

    PtSn alloy, which is a potential material for use in direct methanol fuel cells, can efficiently promote methanol oxidation and alleviate the CO poisoning problem. Herein, methanol decomposition on Pt3Sn(111) was systematically investigated using periodic density functional theory and microkinetic modeling. The geometries and energies of all of the involved species were analyzed, and the decomposition network was mapped out to elaborate the reaction mechanisms. Our results indicated that methanol and formaldehyde were weakly adsorbed, and the other derivatives (CHxOHy, x = 1-3, y = 0-1) were strongly adsorbed and preferred decomposition rather than desorption on Pt3Sn(111). The competitive methanol decomposition started with the initial O-H bond scission followed by successive C-H bond scissions, (i.e., CH3OH → CH3O → CH2O → CHO → CO). The Brønsted-Evans-Polanyi relations and energy barrier decomposition analyses identified the C-H and O-H bond scissions as being more competitive than the C-O bond scission. Microkinetic modeling confirmed that the vast majority of the intermediates and products from methanol decomposition would escape from the Pt3Sn(111) surface at a relatively low temperature, and the coverage of the CO residue decreased with an increase in the temperature and decrease in partial methanol pressure.

  4. The Distribution of Astronomical Aldehydes - the Case for Extended Emission of Acetaldehyde (CH3CHO).

    NASA Astrophysics Data System (ADS)

    Burkhardt, Andrew; Loomis, Ryan; Dollhopf, Niklaus M.; Corby, Joanna F.; Remijan, Anthony

    2014-06-01

    With the advent of new broadband spectral line interferometric observations, we can now begin to fully characterize the spectra and distribution of complex organic molecules that have been largely ignored since their original detections using single dish telescopes. First detected in 1973, acetaldehyde (CH_3CHO) has been detected in numerous sources including TMC-1, Sgr B2(N) and Orion KL (Gottlieb et al 1973; Mathews et al. 1984; Johansson et al. 1991); yet its distribution within these sources is still not well known. Unlike a number of other molecules observed in these regions, acetaldehyde is not observed to be concentrated in hot core regions toward Sgr B2(N), but to have an extended distribution, a trait shared by other aldehydes (Hollis et al. 2001; Chengalur and Kanekar, 2003). An extended distribution may indicate formation through gas phase ion molecule reactions, or that the distribution is a result of non-thermal processes liberating the molecule off grain surfaces. Meanwhile, a compact distribution may indicate warm grain surface chemistry with subsequent desorption by thermal processes. Spatial maps will also help determine abundance correlations with other related molecules such as formic acid, aiding in the investigation of formation routes. In this talk, we present multiple transition maps of acetaldehyde toward Orion KL using both CARMA and the ALMA Band 6 Science Verification data which show evidence of an extended distribution of acetaldehyde, suggesting a similar formation chemistry in Orion KL as suggested by Chengular and Kanekar (2003) towards Sgr B2(N). In addition, spatial correlations to other molecules in the region will be shown, possibly suggesting a common formation chemistry for some aldehydes.

  5. Permanent draft genome of acetaldehyde degradation bacterium, Shewanella sp. YQH10.

    PubMed

    Liu, Yang; Shang, Xiexie; Zeng, Runying

    2015-02-01

    Shewanella sp. YQH10 isolated from mangrove sediment, was a novel species of Shewanella, which has the ability to degrade acetaldehyde. Here, we present an annotated draft genome sequence of Shewanella sp. YQH10, which contains 4,215,794 bp with a G + C content of 48.1%. This information regarding the genetic basis of this bacterium can greatly advance our understanding of the physiology of this species.

  6. Enzymic conversion of ethanol to acetaldehyde as a model recovery system

    SciTech Connect

    Kierstan, M.

    1982-10-01

    Ethanol is readily produced by use of traditional fermentation processes using yeasts, and more recently by use of immobilized cell systems. However, the product concentrations obtained in these systems are limited by the inhibitory effects on the microorganisms of the product, ethanol. Furthermore, the dilute product concentrations thus obtained combined with the relatively high boiling point of ethanol result in systems which require a high degree of energy input for product recovery. Recent advances in genetic engineering techniques offer opportunities for improving the characteristics of the yeasts used in ethanol production. These techniques also provide the potential for improving the production yields of microbial enzymes for specific applications. With this consideration in mind work was undertaken on an enzymic system for removal from a fermentation media of an ethanol product which also results in upgrading of the product. Conversion of ethanol to acetaldehyde can be achieved without the involvement of nicotinamide cofactors by use of the enzyme alcohol oxidase obtainable from Candida boidinii. The product acetaldehyde has a relatively low boiling point (21 degrees C) and, therefore, readily evaporates from systems operating above this temperature. This is compatible with normal operating temperatures for ethanol production. The acetaldehyde so produced can then be readily condensed and be utilized or chemically converted to other products. The production of acetaldehyde is accompanied by production of hydrogen peroxide. The effect of the removal of this product, by the use of catalase, on the primary process was also investigated. The system outlined has potential for development into an immobilized enzyme or cell system which may be made compatible with an immobilized Saccharomyces cerevisiae system for improved efficiency of glucose utilization.

  7. Methanol related deaths in Edirne.

    PubMed

    Azmak, Derya

    2006-01-01

    In this retrospective autopsy study, a detailed analysis of methanol related deaths in Trakya region of Turkey is presented and departmental autopsy records, toxicology and histopathology results are analyzed. We found that methanol poisonings comprise 2.83% of all forensic autopsies (n:18), 88.8% of the cases were male, most of the victims were aged between 41 and 45. Blood methanol concentrations range widely from 55 to 479 mg per 100ml. Ethyl alcohol was detected in 44.4% of the cases. Most of the cases died in hospital and were poisoned through the consumption of alcoholic beverages from illicit sources and colognes. It is important for physicians to be aware of methanol poisoning symptoms and for forensic pathologists to obtain samples for toxicology during autopsies. Some preventative strategies including to routine control of the stores, to prevent the production of illegal alcoholic beverages, etc. should be developed.

  8. Impairment of aldehyde dehydrogenase 2 increases accumulation of acetaldehyde-derived DNA damage in the esophagus after ethanol ingestion

    PubMed Central

    Yukawa, Yoshiyuki; Ohashi, Shinya; Amanuma, Yusuke; Nakai, Yukie; Tsurumaki, Mihoko; Kikuchi, Osamu; Miyamoto, Shin’ichi; Oyama, Tsunehiro; Kawamoto, Toshihiro; Chiba, Tsutomu; Matsuda, Tomonari; Muto, Manabu

    2014-01-01

    Ethanol and its metabolite, acetaldehyde, are the definite carcinogens for esophageal squamous cell carcinoma (ESCC), and reduced catalytic activity of aldehyde dehydrogenase 2 (ALDH2), which detoxifies acetaldehyde, increases the risk for ESCC. However, it remains unknown whether the ALDH2 genotype influences the level of acetaldehyde-derived DNA damage in the esophagus after ethanol ingestion. In the present study, we administered ethanol orally or intraperitoneally to Aldh2-knockout and control mice, and we quantified the level of acetaldehyde-derived DNA damage, especially N2-ethylidene-2’-deoxyguanosine (N2-ethylidene-dG), in the esophagus. In the model of oral ethanol administration, the esophageal N2-ethylidene-dG level was significantly higher in Aldh2-knockout mice compared with control mice. Similarly, in the model of intraperitoneal ethanol administration, in which the esophagus is not exposed directly to the alcohol solution, the esophageal N2-ethylidene-dG level was also elevated in Aldh2-knockout mice. This result indicates that circulating ethanol-derived acetaldehyde causes esophageal DNA damage, and that the extent of damage is influenced by knockout of Aldh2. Taken together, our findings strongly suggest the importance of acetaldehyde-derived DNA damage which is induced in the esophagus of individuals with ALDH2 gene impairment. This provides a physiological basis for understanding alcohol-related esophageal carcinogenesis. PMID:24959382

  9. Impairment of aldehyde dehydrogenase 2 increases accumulation of acetaldehyde-derived DNA damage in the esophagus after ethanol ingestion.

    PubMed

    Yukawa, Yoshiyuki; Ohashi, Shinya; Amanuma, Yusuke; Nakai, Yukie; Tsurumaki, Mihoko; Kikuchi, Osamu; Miyamoto, Shin'ichi; Oyama, Tsunehiro; Kawamoto, Toshihiro; Chiba, Tsutomu; Matsuda, Tomonari; Muto, Manabu

    2014-01-01

    Ethanol and its metabolite, acetaldehyde, are the definite carcinogens for esophageal squamous cell carcinoma (ESCC), and reduced catalytic activity of aldehyde dehydrogenase 2 (ALDH2), which detoxifies acetaldehyde, increases the risk for ESCC. However, it remains unknown whether the ALDH2 genotype influences the level of acetaldehyde-derived DNA damage in the esophagus after ethanol ingestion. In the present study, we administered ethanol orally or intraperitoneally to Aldh2-knockout and control mice, and we quantified the level of acetaldehyde-derived DNA damage, especially N(2) -ethylidene-2'-deoxyguanosine (N(2) -ethylidene-dG), in the esophagus. In the model of oral ethanol administration, the esophageal N(2) -ethylidene-dG level was significantly higher in Aldh2-knockout mice compared with control mice. Similarly, in the model of intraperitoneal ethanol administration, in which the esophagus is not exposed directly to the alcohol solution, the esophageal N(2) -ethylidene-dG level was also elevated in Aldh2-knockout mice. This result indicates that circulating ethanol-derived acetaldehyde causes esophageal DNA damage, and that the extent of damage is influenced by knockout of Aldh2. Taken together, our findings strongly suggest the importance of acetaldehyde-derived DNA damage which is induced in the esophagus of individuals with ALDH2 gene impairment. This provides a physiological basis for understanding alcohol-related esophageal carcinogenesis. PMID:24959382

  10. Pretreatment of rice straw using a butanone or an acetaldehyde dilute solution explosion for producing ethanol.

    PubMed

    Zhang, Jian; Zhang, Wen-Xue; Yang, Jian; Liu, Yue-Hong; Zhong, Xia; Wu, Zheng-Yun; Kida, Kenji; Deng, Yu

    2012-04-01

    Ethanol conversion from rice straw using butanone and acetaldehyde dilute solution explosions was evaluated based on the optimization of pure water explosion. To decrease residual inhibitor content, the exploded slurry was dried and investigated at different temperature. Using a 0.9-mol/L butanone solution explosion, with the explosion pressure set at 3.1 MPa, the residence time at 7 min, the dried rice straw-to-water ratio at 1:3 (w/w), and the exploded slurry drying temperuture at 90 °C for 8 h, the yields of total sugar, glucose, and xylose were 85%, 88%, 82% (w/w), respectively, and the ethanol productivity was 26.0 g/100 g rice straw dry matter. Moreover, 0.5-mol/L acetaldehyde dilute solution explosion improved the efficiency of enzymatic hydrolysis (EH) and simultaneous saccharification and co-fermentation (SSCF), and the residual inhibitors had negligible effects on EH and SSCF after detoxification by drying. The results suggested that compared with pure water explosions, the use of butanone and of acetaldehyde dilute solution explosions lowered the explosive temperature and improved the sugar yield, although relative crystallinity of the rice straw dry matter was increased after the explosion. PMID:22371064

  11. Risk assessment for the Italian population of acetaldehyde in alcoholic and non-alcoholic beverages.

    PubMed

    Paiano, Viviana; Bianchi, Giancarlo; Davoli, Enrico; Negri, Eva; Fanelli, Roberto; Fattore, Elena

    2014-07-01

    Acetaldehyde is a naturally-occurring carcinogenic compound, present in different food items, especially in alcoholic beverages. The aims of this study were to measure acetaldehyde concentration in different beverages consumed in Italy and to estimate the potential cancer risk. The analytical procedure was based on headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS), using the isotopic dilution method. The margin of exposure (MOE) approach of the European Food Safety Authority (EFSA) was used for risk characterisation. The highest concentrations (median, min-max) were detected in grappa samples (499, 23.4-1850mg/l), followed by fruit-based liqueurs and spirits (62.0, 5.23-483mg/l) and wine (68.0, 18.1-477mg/l); the lowest were detected in gin (0.91, 0.78-1.90mg/l). The lowest MOE was estimated for high wine consumers (69). These results suggest that regulatory measures and consumer guidance may be necessary for acetaldehyde in beverages.

  12. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    PubMed Central

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U.; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol. PMID:26788255

  13. Astrochemistry at work in the L1157-B1 shock: acetaldehyde formation

    NASA Astrophysics Data System (ADS)

    Codella, C.; Fontani, F.; Ceccarelli, C.; Podio, L.; Viti, S.; Bachiller, R.; Benedettini, M.; Lefloch, B.

    2015-04-01

    The formation of complex organic molecules (COMs) in protostellar environments is a hotly debated topic. In particular, the relative importance of the gas phase processes as compared to a direct formation of COMs on the dust grain surfaces is so far unknown. We report here the first high-resolution images of acetaldehyde (CH3CHO) emission towards the chemically rich protostellar shock L1157-B1, obtained at 2 mm with the IRAM Plateau de Bure interferometer. Six blueshifted CH3CHO lines with Eu = 26-35 K have been detected. The acetaldehyde spatial distribution follows the young (˜ 2000 yr) outflow cavity produced by the impact of the jet with the ambient medium, indicating that this COM is closely associated with the region enriched by iced species evaporated from dust mantles and released into the gas phase. A high CH3CHO relative abundance, 2-3 × 10-8, is inferred, similarly to what found in hot corinos. Astrochemical modelling indicates that gas phase reactions can produce the observed quantity of acetaldehyde only if a large fraction of carbon, of the order of 0.1 per cent, is locked into iced hydrocarbons.

  14. Effects of acetaldehyde and acrolein on blood pressure in guanethidine-pretreated hypertensive rats

    SciTech Connect

    Green, M.A.; Egle, J.L. Jr.

    1983-06-15

    These experiments were undertaken to study the effect of the interaction of the antihypertensive agent guanethidine and two aldehydes possessing sympathomimetic activity on the blood pressure of spontaneously hypertensive rats (SHR). Acetaldehyde, when administered iv to acutely guanethidine-pretreated (15 mg/kg) SHRs under urethane anesthesia, caused a potentiated pressor response in the dose range of 3 to 40 mg/kg. When administered iv to chronically guanethidine-pretreated SHRs, a pressor response was noted at low doses and a depressor response at high doses. Acrolein (0.05 to 0.5 mg/kg) produced a pressor response at low doses and a depressor response at high doses in both acutely and chronically guanethidine-pretreated SHRs. Pressor responses, particularly to acetaldehyde, may be due to an enlarged tyramine-releasable pool, hyperreactivity of alpha adrenergic receptors of SHRs, or guanethidine inhibition of norepinephrine reuptake. Depressor responses to high doses of aldehydes may be attributed to vagal stimulation or direct vasodilation. It is concluded that there is a significant interaction between the aldehydes and guanethidine which may have implications for someone undergoing treatment with guanethidine for hypertension while being exposed to acetaldehyde and related compounds from ethanol and tobacco smoke.

  15. Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of acetaldehyde

    NASA Astrophysics Data System (ADS)

    Al-Ghamdi, Saleh; Kathuria, Ajay; Abiad, Mohamad; Auras, Rafael

    2016-10-01

    Gamma cyclodextrin (γ-CD) metal organic frameworks (CDMOFs) were synthesized by coordinating γ-CDs with potassium hydroxide (KOH), referred hereafter as CDMOF-a, and potassium benzoate (C7H5KO2), denoted as CDMOF-b. The obtained CDMOF structures were characterized using nitrogen sorption isotherm, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). High surface areas were achieved by the γ-CD based MOF structures where the Langmuir specific surface areas (SSA) of CDMOF-a and CDMOF-b were determined as 1376 m2 g-1 and 607 m2 g-1; respectively. The dehydrated CDMOF structures demonstrated good thermal stability up to 250 °C as observed by the TGA studies. XRD results for CDMOF-a and CDMOF-b reveal a body centered-cubic (BCC) and trigonal crystal system; respectively. Due to its accessible porous structure and high surface area, acetaldehyde was successfully encapsulated in CDMOF-b. During the release kinetic studies, we observed peak release of 53 μg of acetaldehyde per g of CDMOF-b, which was 100 times greater than previously reported encapsulation in β-CD. However, aldol condensation reaction occurred during encapsulation of acetaldehyde into CDMOF-a. This research work demonstrates the potential to encapsulate volatile organic compounds in CDMOF-b, and their associated release for applications including food, pharmaceuticals and packaging.

  16. Effects of using oxygenated fuels on carbon monoxide, formaldehyde and acetaldehyde concentrations in Denver

    SciTech Connect

    Anderson, L.G.; Lanning, J.A.; Wilkes, E.; Jones, R.H.; Wolfe, P.

    1997-12-31

    Oxygenated fuels have been used during the winters in Denver since January 1988, in an attempt to reduce the atmospheric concentration of carbon monoxide. The authors began monitoring ambient concentrations of formaldehyde and acetaldehyde in Denver in December 1987 and have continued that monitoring every winter since. They now have nine seasons of ambient carbonyl data that coincide with oxygenated fuels usage. The authors will present results of the continuing analyses of atmospheric concentration data for CO collected in the Denver area, to determine the effectiveness of the program for reducing ambient CO. The program has been found to have near zero effect at the downtown Denver site, and 5%--12% reductions at several other sites. The formaldehyde and acetaldehyde concentration data will be analyzed to determine the effects of changing oxygenate concentration and composition on carbonyl concentrations. No significant effects have been found on either the concentrations of formaldehyde or acetaldehyde. The authors have also begun analyses of Colorado mandated IM240 emissions test data for CO and NO{sub x} for tests done during an oxygenated fuels period (January, February, November and December 1995) and a nonoxygenated fuels period (April through September 1995). A preliminary analysis of data for more than 100,000 vehicles suggests that oxygenated fuels lead to a reduction of CO emissions of about 13.4% and an increase of NO{sub x} emissions of about 14.6%, as a test fleet weighted average.

  17. Effect of chloral hydrate and acetaldehyde on mitochondrial preparations from sweet potato.

    PubMed

    Pierpoint, W S; Laties, G G

    1966-01-01

    The inhibitory effects of chloral hydrate and acetaldehyde have been studied on oxidations performed by mitochondrial preparations of sweet potatoes (Ipomea batatas). With a variety of substrates, chloral acts very like amytal but only between a fifth and a tenth as effectively; it affects those reactions which would be expected to depend on the oxidation of intramitochondrial DPNH, more than the oxidation of succinate or of added DPNH. It also acts like amytal when oxygen is replaced by other electron accepting agents. It is more effective, for example, against the malate reduction of cytochrome c than against the malate reduction of 2:6-dichlorophenol-indophenol.Inhibitions producd by acetaldehyde are more complex. Some DPN-dependent oxidations, especially those of pyruvate and alpha-keto-glutarate, are strongly inhibited, while that of citrate is not.It is suggested that chloral affects the electron transport sequence of sweet potato mitochondria at a similar locus to amytal. Although the present work fails to provide unambiguous evidence that acetaldehyde acts in the same manner, experiments described in the literature have been interpreted in this way.

  18. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes.

    PubMed

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  19. Acetone-Assisted Oxygen Vacancy Diffusion on TiO2(110)

    SciTech Connect

    Xia, Yaobiao; Zhang, Bo; Ye, Jingyun; Ge, Qingfeng; Zhang, Zhenrong

    2012-10-18

    We have studied the dynamic relationship between acetone and bridge-bonded oxygen (Ob) vacancy (VO) defect sites on the TiO2(110)-1 × 1 surface using scanning tunneling microscopy (STM) and density function theory (DFT) calculations. We report an adsorbate-assisted VO diffusion mechanism. The STM images taken at 300 K show that acetone preferably adsorbs on the VO site and is mobile. The sequential isothermal STM images directly show that the mobile acetone effectively migrates the position of VO by a combination of two acetone diffusion channels: one is the diffusion along the Ob row and moving as an alkyl group, which heals the initial VO; another is the diffusion from the Ob row to the fivecoordinated Ti4+ row and then moving along the Ti4+ row as an acetone, which leaves a VO behind. The calculated acetone diffusion barriers for the two channels are comparable and agree with experimental results.

  20. Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

    USGS Publications Warehouse

    Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

    1988-01-01

    The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

  1. Quantitation of an Acetaldehyde Adduct in Human Leukocyte DNA and the Effect of Smoking Cessation

    PubMed Central

    Chen, Li; Wang, Mingyao; Villalta, Peter W.; Luo, Xianghua; Feuer, Rachel; Jensen, Joni; Hatsukami, Dorothy K.; Hecht, Stephen S.

    2008-01-01

    Acetaldehyde is one of the most prevalent carcinogens in cigarette smoke. It is also a major metabolite of ethanol and is found widely in the human diet and environment. Acetaldehyde DNA adducts are critical for its carcinogenic properties. The role of acetaldehyde DNA adducts in human cancer related to tobacco and alcohol exposure could be investigated with a suitable biomarker. Therefore, in this study we have developed a method for analysis of the major DNA adduct of acetaldehyde, N2-ethylidene-dGuo (1), in human leukocyte DNA. Leukocyte DNA was subjected to enzyme hydrolysis in the presence of NaBH3CN, which converts adduct 1 to N2-ethyl-dGuo (2). [15N5]N2-ethyl-dGuo was used as internal standard. After solid phase extraction, N2-ethyl-dGuo was quantified by LC-ESI-MS/MS-SRM. The method was sensitive, accurate, and precise, and applicable to low microgram amounts of DNA. It was applied to investigate the effect of smoking cessation on levels of adduct 1, measured as adduct 2. Twenty-five smokers who were only light drinkers were eligible for the study. Levels of adduct 2 were quantified at two baseline time points separated by one week, and again after four weeks of abstinence from smoking and alcohol consumption. The mean (± S.D.) levels of adduct 2 measured in the leukocytes of the smokers were 1310 ± 1720 (range 124 – 7700) and 1120 ± 1140 (range 138 – 5760) fmol/μmol dGuo at the two baseline points and 705 ± 438 (range 111 – 1530) fmol/μmol dGuo after 4 weeks of cessation. The median level of adduct 2 decreased significantly by 28% upon quitting smoking (P = 0.02). These results demonstrate that the major acetaldehyde DNA adduct can be reliably quantified by MS/MS methods in human leukocyte DNA and that cigarette smoking has a modest but significant effect on its levels. PMID:17226933

  2. Substrate Specificity of the Purified Primary Alcohol Dehydrogenases from Methanol-Oxidizing Bacteria

    PubMed Central

    Sperl, George T.; Forrest, Hugh S.; Gibson, David T.

    1974-01-01

    Hyphomicrobium strain WC, Pseudomonas strain TP-1, and Pseudomonas strain W1 are capable of growth on methanol as the sole source of carbon and energy. Methanol-grown cells of each organism contain a primary alcohol dehydrogenase that has been purified to homogeneity. Each enzyme has a molecular weight of 120,000 and shows an in vitro requirement for phenazine methosulfate and ammonium ions for enzymatic activity. Normal aliphatic alcohols are oxidized rapidly by each enzyme. The presence of a methyl group on the carbon atom adjacent to the primary alcohol group lowers the enzymatic activity. This effect is reduced as the methyl substituent is moved further away from the hydroxyl group. The effect of other substituents on enzymatic activity is reported. Methanol, formaldehyde, and to a limited extent acetaldehyde are oxidized by the primary alcohol dehydrogenases. Higher aldehydes are not oxidized. A possible explanation for this specificity, with regard to aldehydes, is presented in terms of degree of hydration of the aldehyde. Images PMID:4828309

  3. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, July 1--September 30, 1995

    SciTech Connect

    Eglesia, E.

    1995-10-24

    Mechanistic and kinetic studies of methanol and ethanol coupling reactions on Cs/Cu/ZnO and Cu/ZnO/MnO catalysts using isotopically-labeled compounds have confirmed that coupling reactions proceed via intermediate dehydrogenation of alcohols to aldehydes. Ethanol coupling reactions are much faster than those of methanol because ethanol forms a more thermodynamically favored intermediate (acetaldehyde), with aldol condensation pathways kinetically available for chain growth. Cs decreases the rate of formation of aldehydes in alcohol dehydrogenation reaction and inhibits the undesired conversion of methanol and ethanol to synthesis gas (CO/H{sub 2}). Construction and start-up of the Catalytic Microreactor Unit (CMRU) for high pressure isobutanol synthesis studies have been completed. Initial certification runs have reproduced catalytic CO conversion rates on a standard APCI material (Cs/Cu/ZnO/Al{sub 2}O{sub 3}). Condensation of higher alcohols in the transfer lines appears to be responsible for the observed low apparent selectivity to higher alcohols. The design and construction of the Temperature-Programmed Surface Reaction (TPSR) Unit for the study of the adsorption and reaction properties of alcohols and other oxygenates on isobutanol, synthesis catalysts and components is complete. The reduction of CuO powder and of a Cs/Cu/ZnO catalyst were used to certify the apparatus before proceeding with alcohol adsorption and reaction studies.

  4. Fabrication of a SnO2-based acetone gas sensor enhanced by molecular imprinting.

    PubMed

    Tan, Wenhu; Ruan, Xiaofan; Yu, Qiuxiang; Yu, Zetai; Huang, Xintang

    2015-01-01

    This work presents a new route to design a highly sensitive SnO2-based sensor for acetone gas enhanced by the molecular imprinting technique. Unassisted and acetone-assisted thermal synthesis methods are used to synthesis SnO2 nanomaterials. The prepared SnO2 nanomaterials have been characterized by X-ray powder diffraction, scanning electron microscopy and N2 adsorption-desorption. Four types of SnO2 films were obtained by mixing pure deionized water and liquid acetone with the two types of as-prepared powders, respectively. The acetone gas sensing properties of sensors coated by these films were evaluated. Testing results reveal that the sensor coated by the film fabricated by mixing liquid acetone with the SnO2 nanomaterial synthesized by the acetone-assisted thermal method exhibits the best acetone gas sensing performance. The sensor is optimized for the smooth adsorption and desorption of acetone gas thanks to the participation of acetone both in the procedure of synthesis of the SnO2 nanomaterial and the device fabrication, which results in a distinct response-recovery behavior.

  5. Short-term salivary acetaldehyde increase due to direct exposure to alcoholic beverages as an additional cancer risk factor beyond ethanol metabolism

    PubMed Central

    2011-01-01

    Background An increasing body of evidence now implicates acetaldehyde as a major underlying factor for the carcinogenicity of alcoholic beverages and especially for oesophageal and oral cancer. Acetaldehyde associated with alcohol consumption is regarded as 'carcinogenic to humans' (IARC Group 1), with sufficient evidence available for the oesophagus, head and neck as sites of carcinogenicity. At present, research into the mechanistic aspects of acetaldehyde-related oral cancer has been focused on salivary acetaldehyde that is formed either from ethanol metabolism in the epithelia or from microbial oxidation of ethanol by the oral microflora. This study was conducted to evaluate the role of the acetaldehyde that is found as a component of alcoholic beverages as an additional factor in the aetiology of oral cancer. Methods Salivary acetaldehyde levels were determined in the context of sensory analysis of different alcoholic beverages (beer, cider, wine, sherry, vodka, calvados, grape marc spirit, tequila, cherry spirit), without swallowing, to exclude systemic ethanol metabolism. Results The rinsing of the mouth for 30 seconds with an alcoholic beverage is able to increase salivary acetaldehyde above levels previously judged to be carcinogenic in vitro, with levels up to 1000 μM in cases of beverages with extreme acetaldehyde content. In general, the highest salivary acetaldehyde concentration was found in all cases in the saliva 30 sec after using the beverages (average 353 μM). The average concentration then decreased at the 2-min (156 μM), 5-min (76 μM) and 10-min (40 μM) sampling points. The salivary acetaldehyde concentration depends primarily on the direct ingestion of acetaldehyde contained in the beverages at the 30-sec sampling, while the influence of the metabolic formation from ethanol becomes the major factor at the 2-min sampling point. Conclusions This study offers a plausible mechanism to explain the increased risk for oral cancer associated with

  6. Rapid starting methanol reactor system

    DOEpatents

    Chludzinski, Paul J.; Dantowitz, Philip; McElroy, James F.

    1984-01-01

    The invention relates to a methanol-to-hydrogen cracking reactor for use with a fuel cell vehicular power plant. The system is particularly designed for rapid start-up of the catalytic methanol cracking reactor after an extended shut-down period, i.e., after the vehicular fuel cell power plant has been inoperative overnight. Rapid system start-up is accomplished by a combination of direct and indirect heating of the cracking catalyst. Initially, liquid methanol is burned with a stoichiometric or slightly lean air mixture in the combustion chamber of the reactor assembly. The hot combustion gas travels down a flue gas chamber in heat exchange relationship with the catalytic cracking chamber transferring heat across the catalyst chamber wall to heat the catalyst indirectly. The combustion gas is then diverted back through the catalyst bed to heat the catalyst pellets directly. When the cracking reactor temperature reaches operating temperature, methanol combustion is stopped and a hot gas valve is switched to route the flue gas overboard, with methanol being fed directly to the catalytic cracking reactor. Thereafter, the burner operates on excess hydrogen from the fuel cells.

  7. Effect of acetone accumulation on structure and dynamics of lipid membranes studied by molecular dynamics simulations.

    PubMed

    Posokhov, Yevgen O; Kyrychenko, Alexander

    2013-10-01

    The modulation of the properties and function of cell membranes by small volatile substances is important for many biomedical applications. Despite available experimental results, molecular mechanisms of action of inhalants and organic solvents, such as acetone, on lipid membranes remain not well understood. To gain a better understanding of how acetone interacts with membranes, we have performed a series of molecular dynamics (MD) simulations of a POPC bilayer in aqueous solution in the presence of acetone, whose concentration was varied from 2.8 to 11.2 mol%. The MD simulations of passive distribution of acetone between a bulk water phase and a lipid bilayer show that acetone favors partitioning into the water-free region of the bilayer, located near the carbonyl groups of the phospholipids and at the beginning of the hydrocarbon core of the lipid membrane. Using MD umbrella sampling, we found that the permeability barrier of ~0.5 kcal/mol exists for acetone partitioning into the membrane. In addition, a Gibbs free energy profile of the acetone penetration across a bilayer demonstrates a favorable potential energy well of -3.6 kcal/mol, located at 15-16Å from the bilayer center. The analysis of the structural and dynamics properties of the model membrane revealed that the POPC bilayer can tolerate the presence of acetone in the concentration range of 2.8-5.6 mol%. The accumulation of the higher acetone concentration of 11.2 mol% results, however, in drastic disordering of phospholipid packing and the increase in the membrane fluidity. The acetone molecules push the lipid heads apart and, hence, act as spacers in the headgroup region. This effect leads to the increase in the average headgroup area per molecule. In addition, the acyl tail region of the membrane also becomes less dense. We suggest, therefore, that the molecular mechanism of acetone action on the phospholipid bilayer has many common features with the effects of short chain alcohols, DMSO, and

  8. Evaluating the Potential Importance of Monoterpene Degradation for Global Acetone Production

    NASA Astrophysics Data System (ADS)

    Kelp, M. M.; Brewer, J.; Keller, C. A.; Fischer, E. V.

    2015-12-01

    Acetone is one of the most abundant volatile organic compounds (VOCs) in the atmosphere, but estimates of the global source of acetone vary widely. A better understanding of acetone sources is essential because acetone serves as a source of HOx in the upper troposphere and as a precursor to the NOx reservoir species peroxyacetyl nitrate (PAN). Although there are primary anthropogenic and pyrogenic sources of acetone, the dominant acetone sources are thought to be from direct biogenic emissions and photochemical production, particularly from the oxidation of iso-alkanes. Recent work suggests that the photochemical degradation of monoterpenes may also represent a significant contribution to global acetone production. We investigate that hypothesis using the GEOS-Chem chemical transport model. In this work, we calculate the emissions of eight terpene species (α-pinene, β-pinene, limonene, Δ3-carene, myrcene, sabinene, trans-β-ocimene, and an 'other monoterpenes' category which contains 34 other trace species) and couple these with upper and lower bound literature yields from species-specific chamber studies. We compare the simulated acetone distributions against in situ acetone measurements from a global suite of NASA aircraft campaigns. When simulating an upper bound on yields, the model-to-measurement comparison improves for North America at both the surface and in the upper troposphere. The inclusion of acetone production from monoterpene degradation also improves the ability of the model to reproduce observations of acetone in East Asian outflow. However, in general the addition of monoterpenes degrades the model comparison for the Southern Hemisphere.

  9. An analysis of human response to the irritancy of acetone vapors.

    PubMed

    Arts, J H E; Mojet, J; van Gemert, L J; Emmen, H H; Lammers, J H C M; Marquart, J; Woutersen, R A; Feron, V J

    2002-01-01

    Studies on the irritative effects of acetone vapor in humans and experimental animals have revealed large differences in the lowest acetone concentration found to be irritative to the respiratory tract and eyes. This has brought on much confusion in the process of setting occupational exposure limits for acetone. A literature survey was carried out focusing on the differences in results between studies using subjective (neuro)behavioral methods (questionnaires) and studies using objective measurements to detect odor and irritation thresholds. A critical review of published studies revealed that the odor detection threshold of acetone ranges from about 20 to about 400 ppm. Loss of sensitivity due to adaptation and/or habituation to acetone odor may occur, as was shown in studies comparing workers previously exposed to acetone with previously unexposed subjects. It further appeared that the sensory irritation threshold of acetone lies between 10,000 and 40,000 ppm. Thus, the threshold for sensory irritation is much higher than the odor detection limit, a conclusion that is supported by observations in anosmics, showing a ten times higher irritation threshold level than the odor threshold found in normosmics. The two-times higher sensory irritation threshold observed in acetone-exposed workers compared with previously nonexposed controls can apart from adaptation be ascribed to habituation. An evaluation of studies on subjectively reported irritation at acetone concentrations < 1000 ppm shows that perception of odor intensity, information bias, and exposure history (i.e., habituation) are confounding factors in the reporting of irritation thresholds and health symptoms. In conclusion, subjective measures alone are inappropriate for establishing sensory irritation effects and sensory irritation threshold levels of odorants such as acetone. Clearly, the sensory irritation threshold of acetone should be based on objective measurements. PMID:11852913

  10. Expression of Clostridium acetobutylicum ATCC 824 Genes in Escherichia coli for Acetone Production and Acetate Detoxification

    PubMed Central

    Bermejo, Lourdes L.; Welker, Neil E.; Papoutsakis, Eleftherios T.

    1998-01-01

    A synthetic acetone operon (ace4) composed of four Clostridium acetobutylicum ATCC 824 genes (adc, ctfAB, and thl, coding for the acetoacetate decarboxylase, coenzyme A transferase, and thiolase, respectively) under the control of the thl promoter was constructed and was introduced into Escherichia coli on vector pACT. Acetone production demonstrated that ace4 is expressed in E. coli and resulted in the reduction of acetic acid levels in the fermentation broth. Since different E. coli strains vary significantly in their growth characteristics and acetate metabolism, ace4 was expressed in three E. coli strains: ER2275, ATCC 11303, and MC1060. Shake flask cultures of MC1060(pACT) produced ca. 2 mM acetone, while both strains ER2275(pACT) and ATCC 11303(pACT) produced ca. 40 mM acetone. Glucose-fed cultures of strain ATCC 11303(pACT) resulted in a 150% increase in acetone titers compared to those of batch shake flask cultures. External addition of sodium acetate to glucose-fed cultures of ATCC 11303(pACT) resulted in further increased acetone titers. In bioreactor studies, acidic conditions (pH 5.5 versus 6.5) improved acetone production. Despite the substantial acetone evaporation due to aeration and agitation in the bioreactor, 125 to 154 mM acetone accumulated in ATCC 11303(pACT) fermentations. These acetone titers are equal to or higher than those produced by wild-type C. acetobutylicum. This is the first study to demonstrate the ability to use clostridial genes in nonclostridial hosts for solvent production. In addition, acetone-producing E. coli strains may be useful hosts for recombinant protein production in that detrimental acetate accumulation can be avoided. PMID:9501448

  11. Kinetics of cytochrome P450 2E1-catalyzed oxidation of ethanol to acetic acid via acetaldehyde.

    PubMed

    Bell-Parikh, L C; Guengerich, F P

    1999-08-20

    The P450 2E1-catalyzed oxidation of ethanol to acetaldehyde is characterized by a kinetic deuterium isotope effect that increases K(m) with no effect on k(cat), and rate-limiting product release has been proposed to account for the lack of an isotope effect on k(cat) (Bell, L. C., and Guengerich, F. P. (1997) J. Biol. Chem. 272, 29643-29651). Acetaldehyde is also a substrate for P450 2E1 oxidation to acetic acid, and k(cat)/K(m) for this reaction is at least 1 order of magnitude greater than that for ethanol oxidation to acetaldehyde. Acetic acid accounts for 90% of the products generated from ethanol in a 10-min reaction, and the contribution of this second oxidation has been overlooked in many previous studies. The noncompetitive intermolecular kinetic hydrogen isotope effects on acetaldehyde oxidation to acetic acid ((H)(k(cat)/K(m))/(D)(k(cat)/K(m)) = 4.5, and (D)k(cat) = 1.5) are comparable with the isotope effects typically observed for ethanol oxidation to acetaldehyde, and k(cat) is similar for both reactions, suggesting a possible common catalytic mechanism. Rapid quench kinetic experiments indicate that acetic acid is formed rapidly from added acetaldehyde (approximately 450 min(-1)) with burst kinetics. Pulse-chase experiments reveal that, at a subsaturating concentration of ethanol, approximately 90% of the acetaldehyde intermediate is directly converted to acetic acid without dissociation from the enzyme active site. Competition experiments suggest that P450 2E1 binds acetic acid and acetaldehyde with relatively high K(d) values, which preclude simple tight binding as an explanation for rate-limiting product release. The existence of a rate-determining step between product formation and release is postulated. Also proposed is a conformational change in P450 2E1 occurring during the course of oxidation and the discrimination of P450 2E1 between acetaldehyde and its hydrated form, the gem-diol. This multistep P450 reaction is characterized by kinetic

  12. Adsorption and Reaction of Acetaldehyde on Stoichiometric and Defective SrTiO{sub 3}(100) Surfaces

    SciTech Connect

    Wang, Li Q.; Ferris, Kim F.; Azad, Samina; Engelhard, Mark H.; Peden, Charles HF.

    2004-02-05

    The adsorption and reaction of acetaldehyde (CH{sub 3}CHO), on stoichiometric (TiO{sub 2}-terminated) and reduced SrTiO{sub 3}(100) surfaces, have been investigated using temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Acetaldehyde adsorbs molecularly on the stoichiometric SrTiO{sub 3}(100) surface that contains predominantly Ti{sup 4+} cations. The Ti{sup 4+} sites on the stoichiometric SrTiO{sub 3}(100) surface are not sufficiently active for surface reactions such as aldol condensation, as opposed to the Ti{sup 4+} ions on the TiO{sub 2}(001) surface. However, decomposition and redox reactions of acetaldehyde occur in the presence of surface defects created by Ar{sup +} sputtering. The decomposition products following reactions of acetaldehyde on the defective surface include H{sub 2}, C{sub 2}H{sub 4}, CO, C{sub 4}H{sub 6} and C{sub 4}H{sub 8}. Reductive coupling, to produce C{sub 2}H{sub 4} and C{sub 4}H{sub 8}, is the main reaction pathway for decomposition of acetaldehyde on the sputter reduced SrTiO{sub 3}(100) surface.

  13. Adsorption and Reaction of Acetaldehyde on Shape-Controlled CeO2 Nanocrystals: Elucidation of Structure-function Relationships

    SciTech Connect

    Mann, Amanda K; Wu, Zili; Calaza, Florencia; Overbury, Steven {Steve} H

    2014-01-01

    CeO2 cubes with {100} facets, octahedra with {111} facets, and wires with highly defective structures were utilized to probe the structure-dependent reactivity of acetaldehyde. Using temperature-programmed desorption (TPD), temperature-programmed surface reactions (TPSR), and in situ infrared spectroscopy it was found that acetaldehyde desorbs unreacted or undergoes reduction, coupling, or C-C bond scission reactions depending on the surface structure of CeO2. Room temperature FTIR indicates that acetaldehyde binds primarily as 1-acetaldehyde on the octahedra, in a variety of conformations on the cubes, including coupling products and acetate and enolate species, and primarily as coupling products on the wires. The percent consumption of acetaldehyde follows the order of wires > cubes > octahedra. All the nanoshapes produce the coupling product crotonaldehyde; however, the selectivity to produce ethanol follows the order wires cubes >> octahedra. The selectivity and other differences can be attributed to the variation in the basicity of the surfaces, defects densities, coordination numbers of surface atoms, and the reducibility of the nanoshapes.

  14. Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77.

    PubMed

    Tsuji, Kohsei; Yoon, Ki-Seok; Ogo, Seiji

    2016-03-01

    Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHE(S77)). Interestingly, the ADHE(S77) was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH(4))(2)SO(4) without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHES77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHES77 may play a pivotal role in modulating intracellular acetaldehyde concentration.

  15. [Adsorption characteristics of acetone and butanone onto honeycomb ZSM-5 molecular sieve].

    PubMed

    Du, Juan; Luan, Zhi-Qiang; Xie, Qiang; Ye, Ping-Wei; Li, Kai; Wang, Xi-Qin

    2013-12-01

    Adsorption capacity of acetone and acetone-butanone mixture onto honeycomb ZSM-5 molecular sieve was measured in this paper, and the influences of relative humidity, initial adsorbate concentration and airflow velocity on the adsorption process were investigated. Besides, adsorption performance parameters were calculated by Wheeler's equation. The results showed that relative humidity had no obvious influence on the acetone adsorption performance, which suggests that this material has good hydrophobic ability; in the low concentration range, the dynamic saturated adsorption capacity of acetone increased with the increase of initial concentration, but in the occasion of high concentration of acetone gas (more than 9 mg x L(-1)), the dynamic saturated adsorption capacity maintained at a certain level and did not vary with the increase of initial concentration; the increase of air flow velocity resulted in significant increase of acetone adsorption rate constant, at the same time the critical layer thickness of the adsorbent bed also increased significantly. In the cases of acetone-butanone mixture, the adsorption capacity of butanone onto ZSM-5 was clearly higher than that of acetone.

  16. Increased microsomal interaction with iron and oxygen radical generation after chronic acetone treatment.

    PubMed

    Puntarulo, S; Cederbaum, A I

    1988-01-12

    In vivo administration of acetone influences a variety of reactions catalyzed by rat liver microsomes. The effect of chronic treatment with acetone (1% acetone in the water for 10-12 days) on interaction with iron and subsequent oxygen radical generation by liver microsomes was evaluated. Microsomes from the acetone-treated rats displayed elevated rates of H2O2 generation, an increase in iron-dependent lipid peroxidation, and enhanced chemiluminescence upon the addition of t-butylhydroperoxide. The ferric EDTA-catalyzed production of formaldehyde from DMSO or of ethylene from 2-keto-4-thiomethylbutyrate was increased 2-fold after acetone treatment. This increase in hydroxyl radical generation was accompanied by a corresponding increase in NADPH utilization and was sensitive to inhibition by catalase and a competitive scavenger, ethanol, but not to superoxide dismutase. In vitro addition of acetone to microsomes had no effect on oxygen radical generation. Associated with the chronic acetone treatment was a 2-fold increase in the microsomal content of cytochrome P-450 and in the activity of NADPH-cytochrome-P-450 reductase. It appears that increased oxygen radical generation by microsomes after chronic acetone treatment reflects the increase in the major enzyme components which comprise the mixed-function oxidase system.

  17. What is in that drink: the biological actions of ethanol, acetaldehyde, and salsolinol.

    PubMed

    Deehan, Gerald A; Brodie, Mark S; Rodd, Zachary A

    2013-01-01

    Alcohol abuse and alcoholism represent substantial problems that affect a large portion of individuals throughout the world. Extensive research continues to be conducted in an effort to identify the biological basis of the reinforcing properties of alcohol in order to develop effective pharmacotherapeutic and behavioral interventions. One theory that has developed within the alcohol field over the past four decades postulates that the reinforcing properties of alcohol are due to the action of the metabolites/products of alcohol within the central nervous system (CNS). The most extreme version of this theory suggests that the biologically active metabolites/products of alcohol, created from the breakdown from alcohol, are the ultimate source of the reinforcing properties of alcohol. The contrary theory proposes that the reinforcing properties of alcohol are mediated completely through the interaction of the ethanol molecule with several neurochemical systems within the CNS. While there are scientific findings that offer support for both of these stances, the reinforcing properties of alcohol are most likely generated through a complex series of peripheral and central effects of both alcohol and its metabolites. Nonetheless, the development of a greater understanding for how the metabolites/products of alcohol contribute to the reinforcing properties of alcohol is an important factor in the development of efficacious pharmacotherapies for alcohol abuse and alcoholism. This chapter is intended to provide a historical perspective of the role of acetaldehyde (the first metabolite of alcohol) in alcohol reinforcement as well as review the basic research literature on the effects of acetaldehyde (and acetaldehyde metabolites/products) within the CNS and how these function with regard to alcohol reward.

  18. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, October 1--December 31, 1995

    SciTech Connect

    Iglesia, E.

    1996-01-10

    A series of Cu{sub 0.5}CeMe(II)O{sub x} catalysts (Me refers to Group II alkali earth elements) have been prepared by coprecipitating the corresponding metal nitrates with potassium carbonate. The bulk composition of the catalyst has been determined by atomic absorption (AA) analysis. High-pressure isobutanol synthesis studies have been carried out over a standard BASF Cs-promoted Cu/ZnO/Al{sub 2}O{sub 3} catalyst. At a CO conversion level of 32%, the isobutanol carbon selectivity is about 5%; whereas that of methanol is 40.2%. A 100% selectivity sum has now been obtained as a result of using response factors measured by the laboratory. The reactions of ethanol and acetic acid over a number of catalysts have been investigated using a temperature programmed surface reaction (TPSR) technique. Ethanol and acetone are the only desorption products observed over Cs-promoted Cu/ZnO/Al{sub 2}O{sub 3} catalysts. Surface acetate ion is believed to be the precursor for acetone formation. Over calcined hydrotalcites, i.e., MgO/Al{sub 2}O{sub 3}, ethylene is formed instead of acetone. The amount of ethylene formed decreases as Mg/Al ratio increases, suggesting a role of aluminum ions in ethanol dehydration reactions.

  19. Millimeter and submillimeter wave spectra of mono-13C-acetaldehydes

    NASA Astrophysics Data System (ADS)

    Margulès, L.; Motiyenko, R. A.; Ilyushin, V. V.; Guillemin, J. C.

    2015-07-01

    Context. The acetaldehyde molecule is ubiquitous in the interstellar medium of our galaxy, and due to its dense and complex spectrum, large dipole moment, and several low-lying torsional states, acetaldehyde is considered to be a "weed" molecule for radio astronomy observations. Mono-13C acetaldehydes 13CH3CHO and CH313CHO are likely to be identified in astronomical surveys, such as those available with the very sensitive ALMA telescope. Laboratory measurements and analysis of the millimeter and submillimeter-wave spectra are the prerequisites for the successful radioastronomical search for the new interstellar molecular species, as well as for new isotopologs of already detected interstellar molecules. Aims: In this context, to provide reliable predictions of 13CH3CHO and CH313CHO spectra in millimeter and submillimeter wave ranges, we study rotational spectra of these species in the frequency range from 50 to 945 GHz. Methods: The spectra of mono-13C acetaldehydes were recorded using the spectrometer based on Schottky-diode frequencymultiplication chains in the Lille laboratory. The rotational spectra of 13CH3CHO and CH313CHO molecules were analyzed using the Rho axis method. Results: In the recorded spectra we have assigned 6884 for the 13CH3CHO species and 6458 for CH313CHO species new rotational transitions belonging to the ground, first, and second excited torsional states. These measurements were fitted together with previously published data to the Hamiltonian models that use 91 and 87 parameters to achieve overall weighted rms deviations 0.88 for the 13CH3CHO species and 0.95 for CH313CHO. On the basis of the new spectroscopic results, predictions of transition frequencies in the frequency range up to 1 THz with J ≤ 60 and Ka ≤ 20 are presented for both isotopologs. Full Tables 3-6 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/579/A46

  20. Influence of pyruvate, threonine and phosphoethanolamine on activities of some acetaldehyde-producing enzymes.

    PubMed

    Gerashchenko, D; Gorenshtein, B; Pyzhik, T; Ostrovsky, Y u

    1993-07-01

    Threonine (50 mg/100 g, i.p.) leads to increased hepatic threonine aldolase activity in rats, although endogenous ethanol concentrations remain stable. After pyruvate administration (50 mg/100 g, i.p.), endogenous blood ethanol levels are raised within 30 min, but return to normal at 60 min. The activity of threonine aldolase is decreased in the liver, whereas phosphoethanolamine lyase and pyruvate dehydrogenase activities remain unchanged. Phosphoethanolamine administration (23 mg/100 g, i.p.) did not change the endogenous ethanol concentration or pyruvate dehydrogenase, threonine aldolase and phosphoethanolamine lyase activities. Pyruvate appears to be a better precursor of acetaldehyde than threonine or phosphoethanolamine.

  1. Detection of acetone processing of castor bean mash for forensic investigation of ricin preparation methods.

    PubMed

    Kreuzer, Helen W; Wahl, Jon H; Metoyer, Candace N; Colburn, Heather A; Wahl, Karen L

    2010-07-01

    Samples containing the toxic castor bean protein ricin have been recently seized in connection with biocriminal activity. Analytical methods that enable investigators to determine how the samples were prepared and to match seized samples to potential source materials are needed. One commonly described crude ricin preparation method is acetone extraction of crushed castor beans. Here, we describe the use of solid-phase microextraction and headspace analysis to determine whether castor beans were processed by acetone extraction. We prepared acetone-extracted castor bean mash, along with controls of unextracted mash and mash extracted with nonacetone organic solvents. Samples of acetone-extracted mash and unextracted mash were stored in closed containers for up to 109 days at both room temperature and -20 degrees C, and in open containers at room temperature for up to 94 days. Acetone-extracted bean mash could consistently be statistically distinguished from controls, even after storage in open containers for 94 days. PMID:20345778

  2. Integration of stable isotope and trace contaminant concentration for enhanced forensic acetone discrimination

    SciTech Connect

    Moran, James J.; Ehrhardt, Christopher J.; Wahl, Jon H.; Kreuzer, Helen W.; Wahl, Karen L.

    2013-07-18

    We analyzed 21 neat acetone samples from 15 different suppliers to demonstrate the utility of a coupled stable isotope and trace contaminant strategy for distinguishing forensically-relevant samples. By combining these two pieces of orthogonal data we could discriminate all of the acetones that were produced by the 15 different suppliers. Using stable isotope ratios alone, we were able to distinguish 9 acetone samples, while the remaining 12 fell into four clusters with highly similar signatures. Adding trace chemical contaminant information enhanced discrimination to 13 individual acetones with three residual clusters. The acetones within each cluster shared a common manufacturer and might, therefore, not be expected to be resolved. The data presented here demonstrates the power of combining orthogonal data sets to enhance sample fingerprinting and highlights the role disparate data could play in future forensic investigations.

  3. Boron nitride nanotube based nanosensor for acetone adsorption: a DFT simulation.

    PubMed

    Ganji, Masoud Darvish; Rezvani, Mahyar

    2013-03-01

    We have investigated the adsorption properties of acetone on zigzag single-walled BNNTs using density functional theory (DFT) calculations. The results obtained show that acetone is strongly bound to the outer surface of a (5,0) BNNT on the top site directly above the boron atom, with a binding energy of -96.16 kJ mol(-1) and a B-O binding distance of 1.654 Å. Our first-principles calculations also predict that the ability of zigzag BNNTs to adsorb acetone is significantly stronger than the corresponding ability of zigzag CNTs. A comparative investigation of BNNTs with different diameters indicated that the ability of the side walls of the tubes to adsorb acetone decreases significantly for nanotubes with larger diameters. Furthermore, the stability of the most stable acetone/BNNT complex was tested using ab initio molecular dynamics simulation at room temperature. PMID:23179768

  4. An acetone bio-sniffer (gas phase biosensor) enabling assessment of lipid metabolism from exhaled breath.

    PubMed

    Ye, Ming; Chien, Po-Jen; Toma, Koji; Arakawa, Takahiro; Mitsubayashi, Kohji

    2015-11-15

    Several volatile organic compounds (VOCs) are released from human breath or skin. Like chemical substances in blood or urine, some of these vapors can provide valuable information regarding the state of the human body. A highly sensitive acetone biochemical gas sensor (bio-sniffer) was developed and used to measure exhaled breath acetone concentration, and assess lipid metabolism based on breath acetone analysis. A fiber-optic biochemical gas sensing system was constructed by attaching a flow-cell with nicotinamide adenine dinucleotide (NADH)-dependent secondary alcohol dehydrogenase (S-ADH) immobilized membrane onto a fiber-optic NADH measurement system. The NADH measurement system utilizes an ultraviolet-light emitting diode with peak emission of 335 nm as an excitation light source. NADH is consumed by the enzymatic reaction of S-ADH, and the consumption is proportional to the concentration of acetone vapor. Phosphate buffer which contained NADH was circulated into the flow-cell to rinse products and the excessive substrates from the optode. The change of fluorescent emitted from NADH is analyzed by the PMT. Hence, fluorescence intensity decreased as the acetone concentration increased. The relationship between fluorescence intensity and acetone concentration was identified from 20 ppb to 5300 ppb. This interval included the concentration of acetone vapor in the breath of healthy people and those suffering from disorders of carbohydrate metabolism. Finally, the acetone bio-sniffer was used to measure breath acetone during an exercise stress test on an ergometer after a period of fasting. The concentration of acetone in breath was shown to significantly increase after exercise. This biosensor allows rapid, highly sensitive and selective measurement of lipid metabolism.

  5. An acetone bio-sniffer (gas phase biosensor) enabling assessment of lipid metabolism from exhaled breath.

    PubMed

    Ye, Ming; Chien, Po-Jen; Toma, Koji; Arakawa, Takahiro; Mitsubayashi, Kohji

    2015-11-15

    Several volatile organic compounds (VOCs) are released from human breath or skin. Like chemical substances in blood or urine, some of these vapors can provide valuable information regarding the state of the human body. A highly sensitive acetone biochemical gas sensor (bio-sniffer) was developed and used to measure exhaled breath acetone concentration, and assess lipid metabolism based on breath acetone analysis. A fiber-optic biochemical gas sensing system was constructed by attaching a flow-cell with nicotinamide adenine dinucleotide (NADH)-dependent secondary alcohol dehydrogenase (S-ADH) immobilized membrane onto a fiber-optic NADH measurement system. The NADH measurement system utilizes an ultraviolet-light emitting diode with peak emission of 335 nm as an excitation light source. NADH is consumed by the enzymatic reaction of S-ADH, and the consumption is proportional to the concentration of acetone vapor. Phosphate buffer which contained NADH was circulated into the flow-cell to rinse products and the excessive substrates from the optode. The change of fluorescent emitted from NADH is analyzed by the PMT. Hence, fluorescence intensity decreased as the acetone concentration increased. The relationship between fluorescence intensity and acetone concentration was identified from 20 ppb to 5300 ppb. This interval included the concentration of acetone vapor in the breath of healthy people and those suffering from disorders of carbohydrate metabolism. Finally, the acetone bio-sniffer was used to measure breath acetone during an exercise stress test on an ergometer after a period of fasting. The concentration of acetone in breath was shown to significantly increase after exercise. This biosensor allows rapid, highly sensitive and selective measurement of lipid metabolism. PMID:26079672

  6. The Role of Acetaldehyde in Ethanol-Induced Elevation of the Neuroactive Steroid 3α-hydroxy-5α-pregnan-20-one in Rats

    PubMed Central

    Boyd, Kevin N.; O’Buckley, Todd K.; Morrow, A. Leslie

    2011-01-01

    Background Systemic ethanol administration increases neuroactive steroid levels that increase ethanol sensitivity. Acetaldehyde is a biologically active compound that may contribute to behavioral and rewarding effects of ethanol. We investigated the role of acetaldehyde in ethanol–induced elevations of 3α-hydroxy-5α-pregnan-20-one (3α,5α-THP) levels in cerebral cortex. Methods Male Sprague-Dawley rats were administered ethanol and plasma acetaldehyde concentrations were measured by gas chromatography to determine relevant concentrations. Rats were then administered acetaldehyde directly, acetaldehyde plus cyanamide to block its degradation, or ethanol in the presence of inhibitors of ethanol metabolism, to determine effects on 3α,5α-THP levels in cerebral cortex. Results Ethanol administration (2 g/kg) to rats results in a peak acetaldehyde concentration of 6-7 μM at 10 minutes that remains stable for the duration of the time points tested. Direct administration of acetaldehyde eliciting this plasma concentration does not increase cerebral cortical 3α,5α-THP levels and inhibition of ethanol-metabolizing enzymes to modify acetaldehyde formation does not alter ethanol–induced 3α,5α-THP levels. However, higher doses of acetaldehyde (75 and 100 mg/kg), in the presence of cyanamide to prevent its metabolism, are capable of increasing cortical 3α,5α-THP levels. Conclusions Physiological concentrations of acetaldehyde are not responsible for ethanol-induced increases in 3α,5α-THP, but a synergistic role for acetaldehyde with ethanol may contribute to increases in 3α,5α-THP levels and ethanol sensitivity. PMID:18652594

  7. Multi-Walled Carbon Nanotubes as a Catalyst for Gas-Phase Oxidation of Ethanol to Acetaldehyde.

    PubMed

    Wang, Jia; Huang, Rui; Feng, Zhenbao; Liu, Hongyang; Su, Dangsheng

    2016-07-21

    Multi-walled carbon nanotubes (CNTs) were directly used as a sustainable and green catalyst to convert ethanol into acetaldehyde in the presence of molecular oxygen. The C=O groups generated on the nanocarbon surface were demonstrated as active sites for the selective oxidation of ethanol to acetaldehyde. The transformation of disordered carbon debris on the CNT surface to ordered graphitic structures induced by thermal-treatment significantly enhanced the stability of the active C=O groups, and thus the catalytic performance. A high reactivity with approximately 60 % ethanol conversion and 93 % acetaldehyde selectivity was obtained over the optimized CNT catalyst at 270 °C. More importantly, the catalytic performance was quite stable even after 500 h, which is comparable with a supported gold catalyst. The robust catalytic performance displayed the potential application of CNTs in the industrial catalysis field. PMID:27282126

  8. Air Breathing Direct Methanol Fuel Cell

    DOEpatents

    Ren; Xiaoming

    2003-07-22

    A method for activating a membrane electrode assembly for a direct methanol fuel cell is disclosed. The method comprises operating the fuel cell with humidified hydrogen as the fuel followed by running the fuel cell with methanol as the fuel.

  9. Formation of halogenated acetones in the lower troposphere

    NASA Astrophysics Data System (ADS)

    Sattler, Tobias; Wittmer, Julian; Krause, Torsten; Schöler, Heinz Friedrich; Kamilli, Katharina; Held, Andreas; Zetzsch, Cornelius; Ofner, Johannes; Atlas, Elliot

    2015-04-01

    Western Australia is a semi-/arid region that is heavily influenced by climate change and agricultural land use. The area is known for its saline lakes with a wide range of hydrogeochemical parameters and consists of ephemeral saline and saline groundwater fed lakes with a pH range from 2.5 to 7.1. In 2012 a novel PTFE-chamber was setup directly on the lakes. The 1.5 m³ cubic chamber was made of UV transparent PTFE foil to permit photochemistry while preventing dilution of the air due to lateral wind transport. This experimental setup allows linking measured data directly to the chemistry of and above the salt lakes. Air samples were taken using stainless steel canisters and measured by GC-MS/ECD. Sediment, crust and water samples were taken for investigation of potential VOC and VOX emissions in the laboratory using GC-MS. Several lakes were investigated and canister samples were taken over the day to see diurnal variations. The first samples were collected at 6 a.m. and from this time every 2 hours a canister was filled with chamber air. Concentrations of chloroacetone up to 15 ppb and of bromoacetone up to 40 ppb in the air samples were detected. The concentrations vary over the day and display their highest values around noon. Soil and water samples showed a variety of highly volatile and semi-volatile VOC/VOX but no halogenated acetones. An abiotic formation of these VOC/VOX seems conclusive due to iron-catalysed reactions below the salt crust [1]. The salt crust is the interface through which VOC/VOX pass from soil/groundwater to the atmosphere where they were photochemically altered. This explains the finding of halo acetones only in the air samples and not in water and soil samples measured in the laboratory. The main forming pathway for these haloacetones is the direct halogenation due to atomic chlorine and bromine above the salt lakes [2]. A minor pathway is the atmospheric degradation of chloropropane and bromopropane [3]. These halopropanes were found

  10. Acetone and Water on TiO₂ (110): Competition for Sites

    SciTech Connect

    Henderson, Michael A.

    2005-04-12

    The competitive interaction between acetone and water for surface sites on TiO? (110) was examined using temperature programmed desorption (TPD). Two surface pretreatment methods were employed, one involving vacuum reduction of the surface by annealing at 850 K in ultrahigh vacuum (UHV) and another involving surface oxidation with molecular oxygen. In the former case the surface possessed about 7% oxygen vacancy sites and in the latter reactive oxygen species (adatoms and molecules) were deposited on the surface as a result of oxidative filling of vacancy sites. On the reduced surface, excess water displaced all but about 20% of a saturated d6-acetone first layer to physisorbed desorption states, whereas about 40% of the first layer d6-acetone was stabilized on the oxidized surface against displacement by water through a reaction between oxygen and d6-acetone. The displacement of acetone on both surface is explained in terms of the relative desorption energies of each molecule on the clean surface and role of intermolecular repulsions in shifting their respective desorption features to lower temperatures with increasing coverage. Although first layer water desorbs from TiO? (110) at slightly lower temperature (275 K) than submonolayer coverages of d6-acetone (340 K), intermolecular repulsions between d6-acetone molecules shift its leading edge for desorption to 170 K as the first layer is saturated In contrast, the desorption leading edge for first layer water (with or without coadsorbed d6-acetone) was at 210 K. This small difference in the onsets for d6-acetone and water desorption resulted in the majority of d6-acetone being compressed into islands by water and eventually displaced from the first layer when excess water was adsorbed. On the oxidized surface the species resulting from reaction of d6-acetone and oxygen was not influence by increasing water coverages. This species was stable on the clean surface up to 375 K (well past the first layer water TPD

  11. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

    PubMed

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-07-30

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D

  12. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

    PubMed

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D

  13. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management

    PubMed Central

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no “best-practice method” for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T

  14. Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

    SciTech Connect

    Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

    2006-01-01

    Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

  15. Shock Tube Measurement for the Dissociation Rate Constant of Acetaldehyde Using Sensitive CO Diagnostics.

    PubMed

    Wang, Shengkai; Davidson, David F; Hanson, Ronald K

    2016-09-01

    The rate constant of acetaldehyde thermal dissociation, CH3CHO = CH3 + HCO, was measured behind reflected shock waves at temperatures of 1273-1618 K and pressures near 1.6 and 0.34 atm. The current measurement utilized sensitive CO diagnostics to track the dissociation of CH3CHO via oxygen atom balance and inferred the title rate constant (k1) from CO time histories obtained in pyrolysis experiments of 1000 and 50 ppm of CH3CHO/Ar mixtures. By using dilute test mixtures, the current study successfully suppressed the interferences from secondary reactions and directly determined the title rate constant as k1(1.6 atm) = 1.1 × 10(14) exp(-36 700 K/T) s(-1) over 1273-1618 K and k1(0.34 atm) = 5.5 × 10(12) exp(-32 900 K/T) s(-1) over 1377-1571 K, with 2σ uncertainties of approximately ±30% for both expressions. Example simulations of existing reaction mechanisms updated with the current values of k1 demonstrated substantial improvements with regards to the acetaldehyde pyrolysis chemistry. PMID:27523494

  16. Oxidation of Ethanol to Acetaldehyde over Na-promoted vanadium oxide catalysts

    SciTech Connect

    Chimentao, Ricardo J.; Herrera, Jose L.; Kwak, Ja Hun; Medina, Francesc; Wang, Yong; Peden, Charles HF

    2007-11-20

    Sodium-promoted vanadium oxide catalysts supported on MCM-41 and TiO2 (anatase) were investigated for the partial oxidation of ethanol to acetaldehyde. The catalysts were prepared by incipient wetness impregnation with a vanadium oxide content of 6 wt. %. The experimental characterization was performed by X-ray diffraction (XRD), N2 adsorption, temperature programmed reduction (TPR), and diffuse reflectance UV-Vis. Temperature programmed oxidation (TPO) was also used to identify carbon deposits on the spent catalysts. The presence of sodium plays a strong role in the dispersion and reducibility of the vanadium species as detected by TPR analysis and optical absorption spectroscopy. While sodium addition increases the dispersion of the VOx species, its presence also decreases their reducibility. Additionally, TPO of the spent catalysts revealed that an increase in the Na loading decreases the carbon deposition during reaction. In the case of the catalysts supported on MCM-41, these modifications were mirrored by a change in the activity and selectivity to acetaldehyde. Additionally, on the VOx/TiO2 catalysts the catalytic activity decreased with increasing sodium content in the catalyst. A model in which sodium affects dispersion, reducibility and also acidity of the supported-vanadia species is proposed to explain all these observations.

  17. Acetaldehyde Content and Oxidative Stress in the Deleterious Effects of Alcohol Drinking on Rat Uterine Horn

    PubMed Central

    Buthet, Lara Romina; Maciel, María Eugenia; Quintans, Leandro Néstor; Rodríguez de Castro, Carmen; Costantini, Martín Hernán; Castro, José Alberto

    2013-01-01

    After alcohol exposure through a standard Lieber and De Carli diet for 28 days, a severe atrophy in the rat uteirne horn was observed, accompanied by significant alterations in its epithelial cells. Microsomal pathway of acetaldehyde production was slightly increased. Hydroxyl radicals were detected in the cytosolic fraction, and this was attributed to participation of xanthine oxidoreductase. They were also observed in the microsomal fraction in the presence of NADPH generating system. No generation of 1-hydroxyethyl was evidenced. The t-butylhydroperoxide-induced chemiluminescence analysis of uterine horn homogenates revealed a significant increase in the chemiluminiscence emission due to ethanol exposure. In the animals repeatedly exposed to alcohol, sulfhydryl content from uterine horn proteins was decreased, but no significant changes were observed in the protein carbonyl content from the same samples. Minor but significant decreasing changes were observed in the GSH content accompanied by a tendency to decrease in the GSH/GSSG ratio. A highly significant finding was the diminished activity content of glutathione peroxidase. Results suggest that acetaldehyde accumulation plus the oxidative stress may play an additional effect to the alcohol-promoted hormonal changes in the uterus reported by others after chronic exposure to alcohol. PMID:24348548

  18. Shewanella mangrovi sp. nov., an acetaldehyde-degrading bacterium isolated from mangrove sediment.

    PubMed

    Liu, Yang; Shang, Xie-Xie; Yi, Zhi-Wei; Gu, Li; Zeng, Run-Ying

    2015-08-01

    A taxonomic study was carried out on strain YQH10T, which was isolated from mangrove sediment collected from Zhangzhou, China during the screening of acetaldehyde-degrading bacteria. Cells of strain YQH10T were Gram-stain-negative rods and pale brown-pigmented. Growth was observed at salinities from 0 to 11% and at temperatures from 4 to 42 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YQH10T is affiliated to the genus Shewanella, showing the highest similarity with Shewanella haliotis DW01T (95.7%) and other species of the genus Shewanella (91.4-95.6 %). The principal fatty acids were iso-C15 : 0 and C17 : 1ω8c. The major respiratory quinone was Q-8. The polar lipids comprised phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA had a G+C content of 48.3 mol%. Strain YQH10T can completely degrade 0.02% (w/v) acetaldehyde on 2216E at 28 °C within 48 h. Based on these phenotypic and genotypic data, strain YQH10T represents a novel species of the genus Shewanella, for which the name Shewanella mangrovi sp. nov. is proposed. The type strain is YQH10T ( = MCCC 1A00830T = JCM 30121T). PMID:25957050

  19. Shewanella mangrovi sp. nov., an acetaldehyde-degrading bacterium isolated from mangrove sediment.

    PubMed

    Liu, Yang; Shang, Xie-Xie; Yi, Zhi-Wei; Gu, Li; Zeng, Run-Ying

    2015-08-01

    A taxonomic study was carried out on strain YQH10T, which was isolated from mangrove sediment collected from Zhangzhou, China during the screening of acetaldehyde-degrading bacteria. Cells of strain YQH10T were Gram-stain-negative rods and pale brown-pigmented. Growth was observed at salinities from 0 to 11% and at temperatures from 4 to 42 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YQH10T is affiliated to the genus Shewanella, showing the highest similarity with Shewanella haliotis DW01T (95.7%) and other species of the genus Shewanella (91.4-95.6 %). The principal fatty acids were iso-C15 : 0 and C17 : 1ω8c. The major respiratory quinone was Q-8. The polar lipids comprised phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA had a G+C content of 48.3 mol%. Strain YQH10T can completely degrade 0.02% (w/v) acetaldehyde on 2216E at 28 °C within 48 h. Based on these phenotypic and genotypic data, strain YQH10T represents a novel species of the genus Shewanella, for which the name Shewanella mangrovi sp. nov. is proposed. The type strain is YQH10T ( = MCCC 1A00830T = JCM 30121T).

  20. The (impossible?) formation of acetaldehyde on the grain surfaces: insights from quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Enrique-Romero, J.; Rimola, A.; Ceccarelli, C.; Balucani, N.

    2016-06-01

    Complex Organic Molecules (COMs) have been detected in the interstellar medium (ISM). However, it is not clear whether their synthesis occurs on the icy surfaces of interstellar grains or via a series of gas-phase reactions. As a test case of the COMs synthesis in the ISM, we present new quantum chemical calculations on the formation of acetaldehyde (CH3CHO) from the coupling of the HCO and CH3 radicals, both in gas phase and on water ice surfaces. The binding energies of HCO and CH3 on the amorphous water ice were also computed (2333 and 734 K, respectively). Results indicate that, in gas phase, the products could be either CH3CHO, CH4 + CO, or CH3OCH, depending on the relative orientation of the two radicals. However, on the amorphous water ice, only the CH4 + CO product is possible due to the geometrical constraints imposed by the water ice surface. Therefore, acetaldehyde cannot be synthesized by the CH3 + HCO coupling on the icy grains. We discuss the implications of these results and other cases, such as ethylene glycol and dimethyl ether, in which similar situations can occur, suggesting that formation of these molecules on the grain surfaces might be unlikely.

  1. Centrilobular distribution of acetaldehyde and collagen in the ethanol-fed micropig.

    PubMed

    Halsted, C H; Villanueva, J; Chandler, C J; Ruebner, B; Munn, R J; Parkkila, S; Niemelä, O

    1993-10-01

    We established a new animal model of alcoholic liver disease in the micropig, a species that consumes ethanol voluntarily in the diet. Ten micropigs were pair-fed diets containing 40% of calories as ethanol or cornstarch with identical amounts of fat, protein and micronutrients for 12 mo. Liver histopathology in the ethanol-fed pigs included steatonecrosis in all five and interstitial and perivenous fibrosis in three. Electron microscopy showed Ito-cell transformation with perisinusoidal collagen accumulation. Acetaldehyde adducts were found by immunofluorescence in the centrilobular region and were focused in perivenous zone 3 of all ethanol-fed animals. Protein and triglyceride levels were increased, whereas vitamin A and iron levels were decreased in liver homogenates from ethanol-fed animals. Thus, in this new animal model of alcoholism, ethanol feeding produced the features of alcoholic liver disease concurrent with hepatic deficiency of selected nutrients. Histological and immunofluorescent studies provide in vivo evidence that perivenous collagen deposition is linked to ethanol metabolism and acetaldehyde production.

  2. Interaction of yeasts with the products resulting from the condensation reaction between (+)-catechin and acetaldehyde.

    PubMed

    Lopez-Toledano, Azahara; Villaño-Valencia, Debora; Mayen, Manuel; Merida, Julieta; Medina, Manuel

    2004-04-21

    The condensation reaction between (+)-catechin and acetaldehyde was studied in model solutions in the presence and absence yeasts in order to evaluate its contribution to color changes in fermented drinks such as white wine. On the basis of the results, the yeasts retain the oligomers produced in the reaction, their retention ability increasing for higher polymerization degrees. As a result, the color of model solutions, measured as the absorbance at 420 nm, was found to decrease after the addition of yeasts. On the other hand, the yeasts exhibited no inhibitory effect on the condensation reaction, which took place at the same rate in their presence and absence. At acidity levels and reactant concentrations similar to those in wine, with acetaldehyde in high concentration as it is present in sherry wines, the reaction was found to occur very slowly. Taking into account that Yeasts are present during most of the winemaking process; consequently, they retain oligomers, and the studied reaction could mainly contribute to the alteration of the color of white wine after bottling. PMID:15080649

  3. Enhanced methanol utilization in direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2001-10-02

    The fuel utilization of a direct methanol fuel cell is enhanced for improved cell efficiency. Distribution plates at the anode and cathode of the fuel cell are configured to distribute reactants vertically and laterally uniformly over a catalyzed membrane surface of the fuel cell. A conductive sheet between the anode distribution plate and the anodic membrane surface forms a mass transport barrier to the methanol fuel that is large relative to a mass transport barrier for a gaseous hydrogen fuel cell. In a preferred embodiment, the distribution plate is a perforated corrugated sheet. The mass transport barrier may be conveniently increased by increasing the thickness of an anode conductive sheet adjacent the membrane surface of the fuel cell.

  4. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

  5. Determination of acetone and methyl ethyl ketone in water

    USGS Publications Warehouse

    Tai, D.Y.

    1978-01-01

    Analytical procedures for the determination of acetone and methyl ethyl ketone in water samples were developed. Concentrations in the milligram-per-liter range were determined by injecting an aqueous sample into the analysis system through an injection port, trapping the organics on Tenax-GC at room temperature, and thermally desorbing the organics into a gas chromatograph with a flame ionization detector for analysis. Concentrations in the microgram-per-liter range were determined by sweeping the headspace vapors over a water sample at 50C, trapping on Tenax-GC, and thermally desorbing the organics into the gas chromatograph. The precision for two operators of the milligram-per-liter concentration procedure, expressed as the coefficient of variation, was generally less than 2 percent for concentrations ranging from 16 to 160 milligrams per liter. The precision from two operators of the microgram-per-liter concentration procedure was between 2 and 4 percent for concentrations of 20 and 60 micrograms per liter. (Woodard-USGS)

  6. Biochemical activities of acetone extracts of Hyssopus angustifolius.

    PubMed

    Alinezhad, Heshmatollah; Baharfar, Robabeh; Zare, Mahboobeh; Azimi, Razieh; Nabavi, Seyed Fazel; Nabavi, Seyed Mohammad

    2012-01-01

    Antioxidant and antihemolytic activities of acetone extracts of Hyssopus angustifolius flowers, leaf and stems were investigated employing different in vitro and ex vivo assay systems. IC50, for 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical-scavenging activity were 239.4 +/- 8.4 microg/mL for flowers, 357.8 +/- 11.1 microg/mL for stems and 182.5 +/- 7.5 microg/mL for leaf. All extracts showed moderate nitric oxide scavenging activity. The leaf extract exhibited better hydrogen peroxide scavenging and Fe2+ chelating activity than the others (IC50 were 261.0 +/- 6.2 microg/mL for hydrogen peroxide and 534.0 +/- 9.9 microg/mL for Fe3+ chelating activity). The extracts exhibited good antioxidant activity in linoleic acid peroxidation system and weak reducing power ability. The leaf extract showed better antihemolytic activity than the flower and stem (IC50 = 65.7 +/- 1.8 microg/mL).

  7. Derivatization reaction-based surface-enhanced Raman scattering (SERS) for detection of trace acetone.

    PubMed

    Zheng, Ying; Chen, Zhuo; Zheng, Chengbin; Lee, Yong-Ill; Hou, Xiandeng; Wu, Li; Tian, Yunfei

    2016-08-01

    A facile method was developed for determination of trace volatile acetone by coupling a derivatization reaction to surface-enhanced Raman scattering (SERS). With iodide modified Ag nanoparticles (Ag IMNPs) as the SERS substrate, acetone without obvious Raman signal could be converted to SERS-sensitive species via a chemical derivatization reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH). In addition, acetone can be effectively separated from liquid phase with a purge-sampling device and then any serious interference from sample matrices can be significantly reduced. The optimal conditions for the derivatization reaction and the SERS analysis were investigated in detail, and the selectivity and reproducibility of this method were also evaluated. Under the optimal conditions, the limit of detection (LOD) for acetone was 5mgL(-1) or 0.09mM (3σ). The relative standard deviation (RSD) for 80mgL(-1) acetone (n=9) was 1.7%. This method was successfully used for the determination of acetone in artificial urine and human urine samples with spiked recoveries ranging from 92% to 110%. The present method is convenient, sensitive, selective, reliable and suitable for analysis of trace acetone, and it could have a promising clinical application in early diabetes diagnosis. PMID:27216660

  8. Adsorption and Reaction of Acetone over CeOX(111) Thin Films

    SciTech Connect

    Mullins, David R; Senanayake, Sanjaya D; Gordon, Wesley O; Overbury, Steven {Steve} H

    2009-01-01

    This study reports the interaction of acetone (CH3COCH3), the simplest ketone, with well ordered CeO2(111) thin film surfaces. The fully oxidized CeO2(111) surface shows a weak interaction with acetone with the sole desorption product (TPD) being acetone at 210 K. The chemisorbed molecule binds to the surface as the ?1-acetone species rather than through a bridge-bonded dioxy-configuration. Exposure of a CeO2(111) surface to acetone at 600K removes oxygen as CO and results in the conversion of Ce4+ to Ce3+. Acetone chemisorbs strongly on reduced CeO2-x(111) with molecular acetone desorbing near 500 K. Decomposition also occurs with H2 desorbing between 450 and 600 K and C reacting with O in the ceria to desorb above 650 K. A stable species exists from 200 to 500 K on the reduced surface that has three unique types of C. High resolution C 1s XPS spectra indicate these are Ce-CH2, C-CH3 and C-O species. C k-edge NEXAFS indicates the presence of C{double_bond}C and C{double_bond}O bonds. It is postulated that the intermediate is a carbanion bonded through both O and C atoms to Ce cations.

  9. Derivatization reaction-based surface-enhanced Raman scattering (SERS) for detection of trace acetone.

    PubMed

    Zheng, Ying; Chen, Zhuo; Zheng, Chengbin; Lee, Yong-Ill; Hou, Xiandeng; Wu, Li; Tian, Yunfei

    2016-08-01

    A facile method was developed for determination of trace volatile acetone by coupling a derivatization reaction to surface-enhanced Raman scattering (SERS). With iodide modified Ag nanoparticles (Ag IMNPs) as the SERS substrate, acetone without obvious Raman signal could be converted to SERS-sensitive species via a chemical derivatization reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH). In addition, acetone can be effectively separated from liquid phase with a purge-sampling device and then any serious interference from sample matrices can be significantly reduced. The optimal conditions for the derivatization reaction and the SERS analysis were investigated in detail, and the selectivity and reproducibility of this method were also evaluated. Under the optimal conditions, the limit of detection (LOD) for acetone was 5mgL(-1) or 0.09mM (3σ). The relative standard deviation (RSD) for 80mgL(-1) acetone (n=9) was 1.7%. This method was successfully used for the determination of acetone in artificial urine and human urine samples with spiked recoveries ranging from 92% to 110%. The present method is convenient, sensitive, selective, reliable and suitable for analysis of trace acetone, and it could have a promising clinical application in early diabetes diagnosis.

  10. Adsorption and Reaction of Acetone over CeOx(111) Thin Films

    SciTech Connect

    Senanayake, S.; Gordon, W; Overbury, S; Mullins, D

    2009-01-01

    This study reports the interaction of acetone (CH{sub 3}COCH{sub 3}), the simplest ketone, with well ordered CeO2(111) thin film surfaces. The fully oxidized CeO{sub 2}(111) surface shows a weak interaction with acetone with the sole desorption product (TPD) being acetone at 210 K. The chemisorbed molecule binds to the surface as the 1-acetone species rather than through a bridge-bonded dioxy-configuration. Exposure of a CeO{sub 2}(111) surface to acetone at 600K removes oxygen as CO and results in the conversion of Ce{sup 4+} to Ce{sup 3+}. Acetone chemisorbs strongly on reduced CeO{sub 2-x}(111) with molecular acetone desorbing near 500 K. Decomposition also occurs with H{sub 2} desorbing between 450 and 600 K and C reacting with O in the ceria to desorb above 650 K. A stable species exists from 200 to 500 K on the reduced surface that has three unique types of C. High resolution C 1s XPS spectra indicate these are Ce-CH{sub 2}, C-CH{sub 3} and C-O species. C k-edge NEXAFS indicates the presence of C{double_bond}C and C{double_bond}O bonds. It is postulated that the intermediate is a carbanion bonded through both O and C atoms to Ce cations.

  11. A cross-sectional study of breath acetone based on diabetic metabolic disorders.

    PubMed

    Li, Wenwen; Liu, Yong; Lu, Xiaoyong; Huang, Yanping; Liu, Yu; Cheng, Shouquan; Duan, Yixiang

    2015-02-26

    Breath acetone is a known biomarker for diabetes mellitus in breath analysis. In this work, a cross-sectional study of breath acetone based on clinical metabolic disorders of type 2 diabetes mellitus (T2DM) was carried out. Breath acetone concentrations of 113 T2DM patients and 56 apparently healthy individuals were measured at a single time point. Concentrations varied from 0.22 to 9.41 ppmv (mean 1.75 ppmv) for T2DM, which were significantly higher than those for normal controls (ranged from 0.32 to 1.96 ppmv, mean 0.72 ppmv, p = 0.008). Observations in our work revealed that breath acetone concentrations elevated to different degrees, along with the abnormality of blood glucose, glycated hemoglobin (HbA1c), triglyceride and cholesterol. Breath acetone showed obviously positive correlations with blood ketone and urine ketone. Possible metabolic relations between breath acetone and diabetic disorders were also discussed. This work aimed at giving an overall assessment of breath acetone from the perspective of clinical parameters for type 2 diabetes.

  12. Catalytic function of the mycobacterial binuclear iron monooxygenase in acetone metabolism.

    PubMed

    Furuya, Toshiki; Nakao, Tomomi; Kino, Kuniki

    2015-10-01

    Mycobacteria such as Mycobacterium smegmatis strain mc(2)155 and Mycobacterium goodii strain 12523 are able to grow on acetone and use it as a source of carbon and energy. We previously demonstrated by gene deletion analysis that the mimABCD gene cluster, which encodes a binuclear iron monooxygenase, plays an essential role in acetone metabolism in these mycobacteria. In the present study, we determined the catalytic function of MimABCD in acetone metabolism. Whole-cell assays were performed using Escherichia coli cells expressing the MimABCD complex. When the recombinant E. coli cells were incubated with acetone, a product was detected by gas chromatography (GC) analysis. Based on the retention time and the gas chromatography-mass spectrometry (GC-MS) spectrum, the reaction product was identified as acetol (hydroxyacetone). The recombinant E. coli cells produced 1.02 mM of acetol from acetone within 24 h. Furthermore, we demonstrated that MimABCD also was able to convert methylethylketone (2-butanone) to 1-hydroxy-2-butanone. Although it has long been known that microorganisms such as mycobacteria metabolize acetone via acetol, this study provides the first biochemical evidence for the existence of a microbial enzyme that catalyses the conversion of acetone to acetol.

  13. Interactions of ionic liquids and acetone: thermodynamic properties, quantum-chemical calculations, and NMR analysis.

    PubMed

    Ruiz, Elia; Ferro, Victor R; Palomar, Jose; Ortega, Juan; Rodriguez, Juan Jose

    2013-06-20

    The interactions between ionic liquids (ILs) and acetone have been studied to obtain a further understanding of the behavior of their mixtures, which generally give place to an exothermic process, mutual miscibility, and negative deviation of Raoult's law. COSMO-RS was used as a suitable computational method to systematically analyze the excess enthalpy of IL-acetone systems (>300), in terms of the intermolecular interactions contributing to the mixture behavior. Spectroscopic and COSMO-RS results indicated that acetone, as a polar compound with strong hydrogen bond acceptor character, in most cases, establishes favorable hydrogen bonding with ILs. This interaction is strengthened by the presence of an acidic cation and an anion with dispersed charge and non-HB acceptor character in the IL. COSMO-RS predictions indicated that gas-liquid and vapor-liquid equilibrium data for IL-acetone systems can be finely tuned by the IL selection, that is, acting on the intermolecular interactions between the molecular and ionic species in the liquid phase. NMR measurements for IL-acetone mixtures at different concentrations were also carried out. Quantum-chemical calculations by using molecular clusters of acetone and IL species were finally performed. These results provided additional evidence of the main role played by hydrogen bonding in the behavior of systems containing ILs and HB acceptor compounds, such as acetone. PMID:23688030

  14. Protein precipitation of diluted samples in SDS-containing buffer with acetone leads to higher protein recovery and reproducibility in comparison with TCA/acetone approach.

    PubMed

    Santa, Cátia; Anjo, Sandra I; Manadas, Bruno

    2016-07-01

    Proteomic approaches are extremely valuable in many fields of research, where mass spectrometry methods have gained an increasing interest, especially because of the ability to perform quantitative analysis. Nonetheless, sample preparation prior to mass spectrometry analysis is of the utmost importance. In this work, two protein precipitation approaches, widely used for cleaning and concentrating protein samples, were tested and compared in very diluted samples solubilized in a strong buffer (containing SDS). The amount of protein recovered after acetone and TCA/acetone precipitation was assessed, as well as the protein identification and relative quantification by SWATH-MS yields were compared with the results from the same sample without precipitation. From this study, it was possible to conclude that in the case of diluted samples in denaturing buffers, the use of cold acetone as precipitation protocol is more favourable than the use of TCA/acetone in terms of reproducibility in protein recovery and number of identified and quantified proteins. Furthermore, the reproducibility in relative quantification of the proteins is even higher in samples precipitated with acetone compared with the original sample.

  15. Comment on "Can existing models quantitatively describe the mixing behavior of acetone with water" [J. Chem. Phys. 130, 124516 (2009)].

    PubMed

    Kang, Myungshim; Perera, Aurelien; Smith, Paul E

    2009-10-21

    A recent publication indicated that simulations of acetone-water mixtures using the KBFF model for acetone indicate demixing at mole fractions less than 0.28 of acetone, in disagreement with experiment and two previously published studies. Here, we indicate some inconsistancies in the current study which could help to explain these differences. PMID:20568888

  16. Evaluation of Tribulus terrestris Linn (Zygophyllaceae) acetone extract for larvicidal and repellence activity against mosquito vectors.

    PubMed

    Singh, S P; Raghavendra, K; Singh, R K; Mohanty, S S; Dash, A P

    2008-12-01

    Acetone extracts of leaves and seeds from the Tribulus terrestris (Zygophyllaceae) were tested against mature and immature different mosquito vectors under laboratory condition. The extract showed strong larvicidal, properties 100 per cent mortality in the 3rd-instar larvae was observed in the bioassays with An. culicifacies Giles species A, An. stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti Linn, against 200 ppm of the leaf acetone extract and 100 ppm seed acetone extract. The LC50 values of leaf acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 117, 124, 168 and 185 ppm respectively. The LC50 values of seed acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 100, 72, 91 and 91 ppm respectively. It is confirmed from the LC50 values that the seed acetone extract of T. terrestris is more effective compared to leaf extracts. A significant (P<0.004) higher concentration of acetone extract leaf was required to kill equal number of larvae i.e. against acetone extract of seed. The seed acetone extract showed strong repellent activity against adults mosquitoes. Per cent protection obtained against Anopheles culicifacies species A 100% repellency in 1 h, 6 h; Anopheles stephensi 100% repellency in 0 h, 4 h, 6 h; and Culex quinquefasciatus 100% repellency in 0 h, 2 h, 4 h, at 10% concentration respectively. Against Deet- 2.5% An. culicifacies Giles species A has shown 100% repellency in 1 h, 2 h, 6 h, An. stephensi Liston 99% repellency in 4 h, and Culex quinquefasciatus Say has shown 100% repellency in 1 h, 2 h.

  17. Chronic effects of acetone on the fathead minnow (Pimephales promelas) during early life-stage development

    SciTech Connect

    Mank, M.; Swigert, J.

    1995-12-31

    A 28-day post-hatch early life-stage development toxicity test was conducted to determine the chronic effects of acetone on the fathead minnow (Pimephales promelas). In this study, less than 24-hour old fathead minnow embryos were exposed to 0.25, 0.50, 1.0, 2.0, and 4.0 mL acetone/L and a negative control for a 4-day pre-hatch period and 28 days following hatch. During the pre-hatch period, no adverse effects on embryo survival or hatching success were observed in any of the treatment groups tested when compared to the negative control. From completion of matching to test termination, fathead minnows exposed to 4.0 mL acetone/L, experienced reduced survival, a statistically significant reduction in growth and impairment of critical behavioral functions when compared to the negative control group. Growth of fathead minnows exposed to 2.0 mL acetone/L also experienced a statistically significant effect upon growth when compared to the negative control, however, survival and behavior were not affected during the post-hatch period. Survival, growth, and behavior of fathead minnows exposed to 0.25, 0.50, and 1.0 mL acetone/L from hatching to test termination was comparable to the control group. The no observed effect concentration (NOEC) for fathead minnows exposed to acetone during early life-stage development was 1.0 mL acetone/L, and the lowest observed effect concentration (LOEC) was 2.0 mL acetone/L. The maximum acceptable toxicant concentration (MATC) was calculated to be 1.4 mL acetone/L.

  18. Evaluation of Tribulus terrestris Linn (Zygophyllaceae) acetone extract for larvicidal and repellence activity against mosquito vectors.

    PubMed

    Singh, S P; Raghavendra, K; Singh, R K; Mohanty, S S; Dash, A P

    2008-12-01

    Acetone extracts of leaves and seeds from the Tribulus terrestris (Zygophyllaceae) were tested against mature and immature different mosquito vectors under laboratory condition. The extract showed strong larvicidal, properties 100 per cent mortality in the 3rd-instar larvae was observed in the bioassays with An. culicifacies Giles species A, An. stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti Linn, against 200 ppm of the leaf acetone extract and 100 ppm seed acetone extract. The LC50 values of leaf acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 117, 124, 168 and 185 ppm respectively. The LC50 values of seed acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 100, 72, 91 and 91 ppm respectively. It is confirmed from the LC50 values that the seed acetone extract of T. terrestris is more effective compared to leaf extracts. A significant (P<0.004) higher concentration of acetone extract leaf was required to kill equal number of larvae i.e. against acetone extract of seed. The seed acetone extract showed strong repellent activity against adults mosquitoes. Per cent protection obtained against Anopheles culicifacies species A 100% repellency in 1 h, 6 h; Anopheles stephensi 100% repellency in 0 h, 4 h, 6 h; and Culex quinquefasciatus 100% repellency in 0 h, 2 h, 4 h, at 10% concentration respectively. Against Deet- 2.5% An. culicifacies Giles species A has shown 100% repellency in 1 h, 2 h, 6 h, An. stephensi Liston 99% repellency in 4 h, and Culex quinquefasciatus Say has shown 100% repellency in 1 h, 2 h. PMID:19579717

  19. Characteristics of acetone cluster ion beam for surface processing and modification

    NASA Astrophysics Data System (ADS)

    Ryuto, H.; Kakumoto, Y.; Takeuchi, M.; Takaoka, G. H.

    2014-02-01

    An acetone cluster ion beam was produced by the adiabatic expansion method without using helium as a support gas. The cluster source for the production of ethanol clusters was replaced with that sealed with metal gaskets. The Laval nozzle for the production of ethanol clusters was also replaced with a stainless steel conical nozzle. The cluster size distributions of the acetone cluster ion beams had mean values approximately at 2 × 103 molecules and increased with source pressure. The typical beam current density of the acetone cluster ion beam was approximately 0.5 μA/cm2.

  20. Characteristics of acetone cluster ion beam for surface processing and modification.

    PubMed

    Ryuto, H; Kakumoto, Y; Takeuchi, M; Takaoka, G H

    2014-02-01

    An acetone cluster ion beam was produced by the adiabatic expansion method without using helium as a support gas. The cluster source for the production of ethanol clusters was replaced with that sealed with metal gaskets. The Laval nozzle for the production of ethanol clusters was also replaced with a stainless steel conical nozzle. The cluster size distributions of the acetone cluster ion beams had mean values approximately at 2 × 10(3) molecules and increased with source pressure. The typical beam current density of the acetone cluster ion beam was approximately 0.5 μA/cm(2).

  1. Effects of ALDH2 Genotype, PPI Treatment and L-Cysteine on Carcinogenic Acetaldehyde in Gastric Juice and Saliva after Intragastric Alcohol Administration

    PubMed Central

    Maejima, Ryuhei; Iijima, Katsunori; Kaihovaara, Pertti; Hatta, Waku; Koike, Tomoyuki; Imatani, Akira; Shimosegawa, Tooru; Salaspuro, Mikko

    2015-01-01

    Acetaldehyde (ACH) associated with alcoholic beverages is Group 1 carcinogen to humans (IARC/WHO). Aldehyde dehydrogenase (ALDH2), a major ACH eliminating enzyme, is genetically deficient in 30–50% of Eastern Asians. In alcohol drinkers, ALDH2-deficiency is a well-known risk factor for upper aerodigestive tract cancers, i.e., head and neck cancer and esophageal cancer. However, there is only a limited evidence for stomach cancer. In this study we demonstrated for the first time that ALDH2 deficiency results in markedly increased exposure of the gastric mucosa to acetaldehyde after intragastric administration of alcohol. Our finding provides concrete evidence for a causal relationship between acetaldehyde and gastric carcinogenesis. A plausible explanation is the gastric first pass metabolism of ethanol. The gastric mucosa expresses alcohol dehydrogenase (ADH) enzymes catalyzing the oxidation of ethanol to acetaldehyde, especially at the high ethanol concentrations prevailing in the stomach after the consumption of alcoholic beverages. The gastric mucosa also possesses the acetaldehyde-eliminating ALDH2 enzyme. Due to decreased mucosal ALDH2 activity, the elimination of ethanol-derived acetaldehyde is decreased, which results in its accumulation in the gastric juice. We also demonstrate that ALDH2 deficiency, proton pump inhibitor (PPI) treatment, and L-cysteine cause independent changes in gastric juice and salivary acetaldehyde levels, indicating that intragastric acetaldehyde is locally regulated by gastric mucosal ADH and ALDH2 enzymes, and by oral microbes colonizing an achlorhydric stomach. Markedly elevated acetaldehyde levels were also found at low intragastric ethanol concentrations corresponding to the ethanol levels of many foodstuffs, beverages, and dairy products produced by fermentation. A capsule that slowly releases L-cysteine effectively eliminated acetaldehyde from the gastric juice of PPI-treated ALDH2-active and ALDH2-deficient subjects. These

  2. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    PubMed Central

    Yan, Tingting; Zhao, Yan; Zhang, Xia; Lin, Xiaotong

    2016-01-01

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde on the expression of Bcl-2 family proteins, preventing the reduction of anti-apoptotic protein Bcl-2 and the increase of pro-apoptotic protein Bak induced by acetaldehyde. Further analyses showed that astaxanthin treatment inhibited acetaldehyde-induced reduction of the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). Astaxanthin treatment also prevented acetaldehyde-induced increase of the level of activated p38 mitogen-activated protein kinase (MAPK) and decrease of the level of activated extracellular signal-regulated kinases (ERKs). Activation of Akt/CREB pathway promotes cell survival and is involved in the upregulation of Bcl-2 gene. P38MAPK plays a critical role in apoptotic events while ERKs mediates the inhibition of apoptosis. Thus, astaxanthin may inhibit acetaldehyde-induced apoptosis through promoting the activation of Akt/CREB and ERKs and blocking the activation of p38MAPK. In addition, astaxanthin treatment suppressed the oxidative stress induced by acetaldehyde and restored the antioxidative capacity of SH-SY5Y cells. Therefore, astaxanthin may protect cells against acetaldehyde-induced cytotoxicity through maintaining redox balance and modulating apoptotic and survival signals. The results suggest that astaxanthin treatment may be beneficial for preventing neurotoxicity associated with acetaldehyde and excessive alcohol consumption. PMID:26978376

  3. Uptake measurements of acetaldehyde on solid ice surfaces and on solid/liquid supercooled mixtures doped with HNO3 in the temperature range 203-253 K.

    PubMed

    Petitjean, M; Mirabel, Ph; Le Calvé, S

    2009-04-30

    Uptake of acetaldehyde on ice surfaces has been investigated over the temperature range 203-253 K using a coated wall flow tube coupled to a mass spectrometric detection. The experiments were conducted on pure ice surfaces and on liquid/solid ice mixture both doped with nitric acid (0.063, 0.63, and 6.3 wt %). Uptake of acetaldehyde on these surfaces was always found to be totally reversible whatever the experimental conditions were. The number of acetaldehyde molecules adsorbed per surface unit was conventionally plotted as a function of acetaldehyde concentration in the gas phase. Although the amounts of acetaldehyde adsorbed on solid ice surfaces (pure and HNO(3)-doped ice) were approximately similar and rather limited, the number of acetaldehyde molecules taken up on the HNO(3)-doped solid ice/liquid mixtures are significantly higher, up to 1 or 2 orders of magnitudes compared to pure ice surfaces. At 213 K for example and for low concentrations of acetaldehyde (<1 x 10(13) molecule cm(-3)), the amount of acetaldehyde molecules taken up on solid/liquid doped surfaces is 3.3 and 8.8 times higher than those measured on pure ice respectively for 0.063 and 0.63 wt % of HNO(3). The huge quantities of acetaldehyde taken up by liquid-/solid-doped mixtures are likely dissolved in the nonhomogeneous liquid part of the surfaces according to the Henry's law equilibrium. As a consequence, up to about 10% of acetaldehyde may be scavenged by supercooled liquid droplets of convective clouds in the upper troposphere.

  4. The direct methanol fuel cell

    SciTech Connect

    Halpert, G.; Narayanan, S.R.; Frank, H.

    1995-08-01

    This presentation describes the approach and progress in the ARPA-sponsored effort to develop a Direct Methanol, Liquid-Feed Fuel Cell (DMLFFC) with a solid Polymer Electrolyte Membrane (PEM) for battery replacement in small portable applications. Using Membrane Electrode Assemblies (MEAs) developed by JPL and Giner, significant voltage was demonstrated at relatively high current densities. The DMLFFC utilizes a 3 percent aqueous solution of methanol that is oxidized directly in the anode (fuel) chamber and oxygen (air) in the cathode chamber to produce water and significant power. The only products are water and CO{sub 2}. The ARPA effort is aimed at replacing the battery in the BA 5590 military radio.

  5. Methanol production method and system

    DOEpatents

    Chen, Michael J.; Rathke, Jerome W.

    1984-01-01

    Ethanol is selectively produced from the reaction of methanol with carbon monoxide and hydrogen in the presence of a transition metal carbonyl catalyst. Methanol serves as a solvent and may be accompanied by a less volatile co-solvent. The solution includes the transition metal carbonyl catalysts and a basic metal salt such as an alkali metal or alkaline earth metal formate, carbonate or bicarbonate. A gas containing a high carbon monoxide to hydrogen ratio, as is present in a typical gasifer product, is contacted with the solution for the preferential production of ethanol with minimal water as a byproduct. Fractionation of the reaction solution provides substantially pure ethanol product and allows return of the catalysts for reuse.

  6. Withanolide artifacts formed in methanol.

    PubMed

    Cao, Cong-Mei; Zhang, Huaping; Gallagher, Robert J; Timmermann, Barbara N

    2013-11-22

    Methanol solutions of the main withanolides (6-8) naturally present in Physalis longifolia yielded five artificial withanolides (1-5), including three new compounds (1-3). Withanolides 1 and 2 were identified as intramolecular Michael addition derivatives, while withanolides 3-5 were the result of intermolecular Michael addition. A comprehensive literature investigation was conducted to identify potential withanolide Michael addition artifacts isolated from Solanaceous species to date.

  7. Studies on methanol - oxidizing yeast. III. Enzyme.

    PubMed

    Volfová, O

    1975-01-01

    Oxidation of methanol, formaldehyde and formic acid was studied in cells and cell-free extract of the yeast Candida boidinii No. 11Bh. Methanol oxidase, an enzyme oxidizing methanol to formaldehyde, was formed inducibly after the addition of methanol to yeast cells. The oxidation of methanol by cell-free extract was dependent on the presence of oxygen and independent of any addition of nicotine-amide nucleotides. Temperature optimum for the oxidation of methanol to formaldehyde was 35 degrees C, pH optimum was 8.5. The Km for methanol was 0.8mM. The cell-free extract exhibited a broad substrate specificity towards primary alcohols (C1--C6). The activity of methanol oxidase was not inhibited by 1mM KCN, EDTA or monoiodoacetic acid. The strongest inhibitory action was exerted by p-chloromercuribenzoate. Both the cells and the cell-free extract contained catalase which participated in the oxidation of methanol to formaldehyde; the enzyme was constitutively formed by the yeast. The pH optimum for the degradation of H2O2 was in the same range as the optimum for methanol oxidation, viz. at 8.5. Catalase was more resistant to high pH than methanol oxidase. The cell-free extract contained also GSH-dependent NAD-formaldehyde dehydrogenase with Km = 0.29mM and NAD-formate dehydrogenase with Km = 55mM. PMID:240764

  8. Direct methanol fuel cell and system

    DOEpatents

    Wilson, Mahlon S.

    2004-10-26

    A fuel cell having an anode and a cathode and a polymer electrolyte membrane located between anode and cathode gas diffusion backings uses a methanol vapor fuel supply. A permeable polymer electrolyte membrane having a permeability effective to sustain a carbon dioxide flux equivalent to at least 10 mA/cm.sup.2 provides for removal of carbon dioxide produced at the anode by reaction of methanol with water. Another aspect of the present invention includes a superabsorpent polymer material placed in proximity to the anode gas diffusion backing to hold liquid methanol or liquid methanol solution without wetting the anode gas diffusion backing so that methanol vapor from the liquid methanol or liquid methanol-water solution is supplied to the membrane.

  9. Amidic and acetonic cryoprotectants improve cryopreservation of volvocine green algae.

    PubMed

    Nakazawa, A; Nishii, I

    2012-01-01

    A number of volvocalean green algae species were subjected to a two-step cryopreservation protocol with various cryoprotectants. Potential cryoprotectants were methanol (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N-methylformamide, and hydroxyacetone (HA). We confirmed prior reports that MeOH was effective for cryopreserving Chlamydomonas, but did not work well for larger volvocaleans such as Volvox. In contrast, DMF and HA were effective for both unicellular and multicellular representatives. When we used a cold-inducible transposon to probe Southern blots of Volvox DNA samples taken before and after storage for one month in LN, we could detect no differences, indicating that the genome had remained relatively stable and that the transposon had not been induced by the cryopreservation procedure. We believe these methods will facilitate long-term storage of several volvocine algal species, including Volvox strains harboring transposon-induced mutations of developmental interest. PMID:22825787

  10. The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment

    PubMed Central

    Scheer, Marc A.; Schneider, Katrina J.; Finnigan, Rochelle L.; Maloney, Eamon P.; Wells, Mark A.; Clemens, Dahn L.

    2016-01-01

    Background: Hepatocytes metabolize the vast majority of ingested ethanol. This metabolic activity results in hepatic toxicity and impairs the ability of hepatocytes to replicate. Previous work by our group has shown that ethanol metabolism results in a G2/M cell cycle arrest. The intent of these studies was to discern the roles of acetaldehyde and reactive oxygen, two of the major by-products of ethanol metabolism, in the G2/M cell cycle arrest. Methods: To investigate the role of ethanol metabolites in the cell cycle arrest, VA-13 and VL-17A cells were used. These are recombinant Hep G2 cells that express alcohol dehydrogenase or alcohol dehydrogenase and cytochrome P450 2E1, respectively. Cells were cultured with or without ethanol, lacking or containing the antioxidants N-acetylcysteine (NAC) or trolox, for three days. Cellular accumulation was monitored by the DNA content of the cultures. The accumulation of the cyclin-dependent kinase, Cdc2 in the inactive phosphorylated form (p-Cdc2) and the cyclin-dependent kinase inhibitor p21 were determined by immunoblot analysis. Results: Cultures maintained in the presence of ethanol demonstrated a G2/M cell cycle arrest that was associated with a reduction in DNA content and increased levels of p-Cdc2 and p21, compared with cells cultured in its absence. Inclusion of antioxidants in the ethanol containing media was unable to rescue the cells from the cell cycle arrest or these ethanol metabolism-mediated effects. Additionally, culturing the cells in the presence of acetaldehyde alone resulted in increased levels of p-Cdc2 and p21. Conclusions: Acetaldehyde produced during ethanol oxidation has a major role in the ethanol metabolism-mediated G2/M cell cycle arrest, and the concurrent accumulation of p21 and p-Cdc2. Although reactive oxygen species are thought to have a significant role in ethanol-induced hepatocellular damage, they may have a less important role in the inability of hepatocytes to replace dead or damaged

  11. Thz Spectroscopy of 13C Isotopic Species of a "weed": Acetaldehyde

    NASA Astrophysics Data System (ADS)

    Margulès, L.; Motiyenko, R. A.; Guillemin, J.-C.

    2011-06-01

    Our studies of the isotopic species of 13C and D isotopologues of methyl formate (HCOOCH_3), have allowed the detection of more than 600 lines in Orion. This confirms that many observed U-lines are coming from isotopic species of one of the most abundant molecules in space. Since its first detection in 1976 in SgrB2 and in Orion A, acetaldehyde (CH_3CHO) was detected in many other numerous objects. If its deuterated species (CD_3CHO and CH_3CDO) have been previously studied in the millimeterwave range, the data concerning the 13C species are limited to few lines measured in 1957 up to 40 GHz. In this context we decided to study the 13C species of acetaldehyde. Acetaldehyde molecule displays a large amplitude motion: the hindered rotation of the methyl group with respect to the rest of the molecule. The analysis is performed with the Rho Axis Method. Recent versions of the codes include high orders term in order to reproduce the observed frequencies for large quantum numbers values as J-values as high as 70a,b,. Measurements and analysis of the rotational spectra of 13C isotopic species are in progress in Lille with a solid-state submillimetre-wave spectrometer (50-950 GHz), the first results will be presented. This work is supported by the contract ANR-08-BLAN-0054 and by the Programme National de Physico-Chimie du Milieu Interstellaire (PCMI-CNRS). Carvajal, M.; Margulès, L.; Tercero, B.; et al.A&A 500, (2009) 1109 Margulès, L.; Huet, T. R.; Demaison J.; et al.,ApJ 714, (2010) 1120. Ikeda, M.; Ohishi, M.; Nummelin, A.; et al., ApJ, 560, (2001) 792 Kleiner, I.; Lopez, J.-C.; Blanco, S.; et al.J. Mol. Spectrosc. 197, (1999) 275 Elkeurti M.; Coudert, L. H.; Medvedev, I. R.; et al.J. Mol. Spectrosc. 263, (2010) 145 Kilb, R.W.; Lin, C.C.; and Wilson, E.B.J. Chem. Phys. 26, (1957) 1695 Kleiner, I. J. Mol. Spectrosc. 260, (2010) 1 Ilyushin, V.V.; Kryvda, A; and Alekseev, E;J. Mol. Spectrosc. 255, (2009) 32

  12. Biomarkers of Exposure and Effect in Human Lymphoblastoid TK6 Cells Following [13C2]-Acetaldehyde Exposure

    PubMed Central

    Swenberg, James A.

    2013-01-01

    The dose-response relationship for biomarkers of exposure (N2-ethylidene-dG adducts) and effect (cell survival and micronucleus formation) was determined across 4.5 orders of magnitude (50nM–2mM) using [13C2]-acetaldehyde exposures to human lymphoblastoid TK6 cells for 12h. There was a clear increase in exogenous N 2-ethylidene-dG formation at exposure concentrations ≥ 1µM, whereas the endogenous adducts remained nearly constant across all exposure concentrations, with an average of 3.0 adducts/107 dG. Exogenous adducts were lower than endogenous adducts at concentrations ≤ 10µM and were greater than endogenous adducts at concentrations ≥ 250µM. When the endogenous and exogenous adducts were summed together, statistically significant increases in total adduct formation over the endogenous background occurred at 50µM. Cell survival and micronucleus formation were monitored across the exposure range and statistically significant decreases in cell survival and increases in micronucleus formation occurred at ≥ 1000µM. This research supports the hypothesis that endogenously produced reactive species, including acetaldehyde, are always present and constitute the majority of the observed biological effects following very low exposures to exogenous acetaldehyde. These data can replace default assumptions of linear extrapolation to very low doses of exogenous acetaldehyde for risk prediction. PMID:23425604

  13. Effect of oxygen on the conversion of acetaldehyde in homogeneous plasmas of N2/O2/CH3CHO mixtures

    NASA Astrophysics Data System (ADS)

    Faider, W.; Pasquiers, S.; Blin-Simiand, N.; Magne, L.

    2013-12-01

    A photo-triggered discharge producing a homogeneous plasma was used to investigate, experimentally and with the help of a self-consistent 0D model, the decomposition processes of acetaldehyde (concentration up to 0.5%) in N2/O2/CH3CHO mixtures containing up to 20% oxygen, at a total pressure of 460 mbar. This work follows a previous one about N2/CH3CHO, having provided the necessary data about the quenching of the N2 metastable states by the acetaldehyde molecule. For the condition of the experiment, it was shown that oxygen has a weak influence on the acetaldehyde removal. Nevertheless, the kinetic reactions involved drastically change when the oxygen percentage is increased. Quenching reactions gradually give way to oxidation reactions by O(3P) and OH. Oxidation by OH dominates for a high acetaldehyde concentration or a high oxygen percentage. Moreover, CH3 is an important primary compound for the formation of CH4 and C2H6. Ethane is less populated than methane in the whole range of oxygen percentage values studied, and there are still hydrocarbon molecules in the gas mixture at 20% oxygen. This is well explained by the adopted kinetic scheme.

  14. Replacement of the initial steps of ethanol metabolism in Saccharomyces cerevisiae by ATP-independent acetylating acetaldehyde dehydrogenase.

    PubMed

    Kozak, Barbara U; van Rossum, Harmen M; Niemeijer, Matthijs S; van Dijk, Marlous; Benjamin, Kirsten; Wu, Liang; Daran, Jean-Marc G; Pronk, Jack T; van Maris, Antonius J A

    2016-03-01

    In Saccharomyces cerevisiae ethanol dissimilation is initiated by its oxidation and activation to cytosolic acetyl-CoA. The associated consumption of ATP strongly limits yields of biomass and acetyl-CoA-derived products. Here, we explore the implementation of an ATP-independent pathway for acetyl-CoA synthesis from ethanol that, in theory, enables biomass yield on ethanol that is up to 40% higher. To this end, all native yeast acetaldehyde dehydrogenases (ALDs) were replaced by heterologous acetylating acetaldehyde dehydrogenase (A-ALD). Engineered Ald(-) strains expressing different A-ALDs did not immediately grow on ethanol, but serial transfer in ethanol-grown batch cultures yielded growth rates of up to 70% of the wild-type value. Mutations in ACS1 were identified in all independently evolved strains and deletion of ACS1 enabled slow growth of non-evolved Ald(-) A-ALD strains on ethanol. Acquired mutations in A-ALD genes improved affinity-Vmax/Km for acetaldehyde. One of five evolved strains showed a significant 5% increase of its biomass yield in ethanol-limited chemostat cultures. Increased production of acetaldehyde and other by-products was identified as possible cause for lower than theoretically predicted biomass yields. This study proves that the native yeast pathway for conversion of ethanol to acetyl-CoA can be replaced by an engineered pathway with the potential to improve biomass and product yields.

  15. Quantitative Determination of Acetaldehyde in Foods Using Automated Digestion with Simulated Gastric Fluid Followed by Headspace Gas Chromatography

    PubMed Central

    Uebelacker, Michael; Lachenmeier, Dirk W.

    2011-01-01

    Acetaldehyde (ethanal) is a genotoxic carcinogen, which may occur naturally or as an added flavour in foods. We have developed an efficient method to analyze the compound in a wide variety of food matrices. The analysis is conducted using headspace (HS) gas chromatography (GC) with flame ionization detector. Using a robot autosampler, the samples are digested in full automation with simulated gastric fluid (1 h at 37°C) under shaking, which frees acetaldehyde loosely bound to matrix compounds. Afterwards, an aliquot of the HS is injected into the GC system. Standard addition was applied for quantification to compensate for matrix effects. The precision of the method was sufficient (<3% coefficient of variation). The limit of detection was 0.01 mg/L and the limit of quantification was 0.04 mg/L. 140 authentic samples were analyzed. The acetaldehyde content in apples was 0.97 ± 0.80 mg/kg, orange juice contained 3.86 ± 2.88 mg/kg. The highest concentration was determined in a yoghurt (17 mg/kg). A first-exposure estimation resulted in a daily acetaldehyde intake of less than 0.1 mg/kg bodyweight from food, which is considerably lower than the exposures from alcohol consumption or tobacco smoking. PMID:21747735

  16. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 April--30 June 30 1996

    SciTech Connect

    1996-07-25

    A series of CuMgCeO{sub x} catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. Kinetic studies of methanol and ethanol coupling reactions on K-Cu/MgO/CeO{sub 2} and MgO/CeO{sub 2} catalysts indicate that Cu enhances the rates of alcohol dehydrogenation. The cross-coupling reactions of acetaldehyde and {sup 13}C-labeled methanol produce singly-labeled propionaldehyde, suggesting that it forms by the condensation of acetaldehyde and a reactive intermediate derived from methanol. Isobutyraldehyde, a precursor to isobutanol, forms via the condensation of propionaldehyde and a reactive C{sub 1} intermediate resulting from methanol. CO{sub 2}, one of the reaction products, poisons both basic and metal sites on Ce-containing CuMgO{sub x} catalysts, resulting in decreases in the rates of both alcohol dehydrogenation (Cu sites) and chain-growth condensation reactions (basic sites). CO{sub 2} inhibits ethanol dehydrogenation on both low-Cu and high-Cu CuMgCeO{sub x} catalysts; however, CO{sub 2} has no effect on the activity of low-Cu Ce-free Cu-MgO{sub x} catalysts, suggesting that the Cu on CuMgCeO{sub x} catalysts is more likely to be oxidized by CO{sub 2} to Cu{sup +} species that can be subsequently stabilized by CeO{sub 2}. CO{sub 2} effects on high-pressure isobutanol synthesis from CO/H{sub 2} have been studied on low- and high-Cu CuMgCeO{sub x} catalysts at 320{degrees}C and 4.5 MPa. CO{sub 2} addition and removal on low- and high-Cu catalysts show similar directional effects on CO conversion. CO conversion is lower at all space velocities in the presence of CO{sub 2}, and removal Of CO{sub 2} from the feed partially recovers CO conversion. CO{sub 2} decreases methanol and isobutanol productivities on both catalysts. Addition of 1-propanol to CO/H{sub 2} feed increases isobutanol production, suggesting that 1-propanol is a precursor to isobutanol.

  17. DFT study on the chemical sensitivity of C3N nanotubes toward acetone

    NASA Astrophysics Data System (ADS)

    Bagheri, Zargham

    2016-02-01

    Potential application of single-walled C3N nanotubes was investigated as chemical sensors for acetone molecules based on the density functional theory calculations. It was found that the pristine nanotube weakly adsorbs an acetone molecule with the adsorption energy of - 9.7 kcal/mol, and its electronic properties are not sensitive to this molecule. By replacing a C atom with a Si atom, the nanotube becomes a p-type semiconductor. The adsorption energy of the acetone molecule on the Si-doped nanotube becomes much more negative (Ead=-67.4 kcal/mol). The adsorption process leads to a sizable increase in the resistance of the Si-doped tube, thereby, it can show the presence of acetone molecule, creating an electronic signal. Also, the sensitivity of these devices can be controlled by the doping level of Si atoms. By increasing the number of dopant atoms from 1 to 4, the sensitivity is gradually increased.

  18. Preparation of spherical optical microresonators and their resonance spectra in air and gaseous acetone

    NASA Astrophysics Data System (ADS)

    Matějec, Vlastimil; Todorov, Filip; Jelínek, Michal; Fibrich, Martin; Chomát, Miroslav; Kubeček, Vaclav; Barton, Ivo; Martan, Tomas; Berková, Daniela

    2012-02-01

    This paper deals with the preparation of spherical silica whispering-gallery-mode (WGM) microresonators and with their resonance spectra measured in air and in acetone vapors. Spherical microresonators with a diameter ranging from 320 to 360 micrometers have been prepared by heating the tip of a silica fiber by a hydrogen-oxygen burner. Details of this preparation are shown on spherical and spheroidal microresonators. The prepared microspheres were excited by a fiber taper and their resonance spectra were measured and Q factors estimated. Changes in the resonance spectra of the microspheres due to their contact with acetone vapor heated to 55 °C or with liquid acetone have been observed. These changes are explained by interaction of acetone with silica and by temperature changes of the microspheres.

  19. Electrocatalytic reduction of acetone in a proton-exchange-membrane reactor: a model reaction for the electrocatalytic reduction of biomass.

    PubMed

    Green, Sara K; Tompsett, Geoffrey A; Kim, Hyung Ju; Bae Kim, Won; Huber, George W

    2012-12-01

    Acetone was electrocatalytically reduced to isopropanol in a proton-exchange-membrane (PEM) reactor on an unsupported platinum cathode. Protons needed for the reduction were produced on the unsupported Pt-Ru anode from either hydrogen gas or electrolysis of water. The current efficiency (the ratio of current contributing to the desired chemical reaction to the overall current) and reaction rate for acetone conversion increased with increasing temperature or applied voltage for the electrocatalytic acetone/water system. The reaction rate and current efficiency went through a maximum with respect to acetone concentration. The reaction rate for acetone conversion increased with increasing temperature for the electrocatalytic acetone/hydrogen system. Increasing the applied voltage for the electrocatalytic acetone/hydrogen system decreased the current efficiency due to production of hydrogen gas. Results from this study demonstrate the commercial feasibility of using PEM reactors to electrocatalytically reduce biomass-derived oxygenates into renewable fuels and chemicals. PMID:22961747

  20. Electrocatalytic reduction of acetone in a proton-exchange-membrane reactor: a model reaction for the electrocatalytic reduction of biomass.

    PubMed

    Green, Sara K; Tompsett, Geoffrey A; Kim, Hyung Ju; Bae Kim, Won; Huber, George W

    2012-12-01

    Acetone was electrocatalytically reduced to isopropanol in a proton-exchange-membrane (PEM) reactor on an unsupported platinum cathode. Protons needed for the reduction were produced on the unsupported Pt-Ru anode from either hydrogen gas or electrolysis of water. The current efficiency (the ratio of current contributing to the desired chemical reaction to the overall current) and reaction rate for acetone conversion increased with increasing temperature or applied voltage for the electrocatalytic acetone/water system. The reaction rate and current efficiency went through a maximum with respect to acetone concentration. The reaction rate for acetone conversion increased with increasing temperature for the electrocatalytic acetone/hydrogen system. Increasing the applied voltage for the electrocatalytic acetone/hydrogen system decreased the current efficiency due to production of hydrogen gas. Results from this study demonstrate the commercial feasibility of using PEM reactors to electrocatalytically reduce biomass-derived oxygenates into renewable fuels and chemicals.

  1. Preparation and photocatalytic properties of TiO2/mica composite for acetaldehyde degradation

    NASA Astrophysics Data System (ADS)

    Ozawa, Masakuni; Matui, Hidetomo; Suzuki, Suguru

    2016-01-01

    TiO2/mica composite was prepared by mixing mica and acidic solution of hydrolyzed titanium tetraisopropoxide, and characterized by X-ray diffraction (XRD), thermogravimetry and differential thermal analysis (TG-DTA), and N2 adsorption measurement. The results of experiments showed that the material had a catalytic composite powder structure containing pillared fragments with TiO2 after calcination at 300-800 °C. The resulting TiO2/mica exhibited good thermal stability, as indicated by its porosity and surface area, and interlayer stability of powders after calcination at 800 °C. The photocatalytic performances of these porous mica/TiO2 composites were evaluated by gaseous acetaldehyde degradation. The superior photocatalyic property was demonstrated and the maximum removal efficiency was up to 99% within 90 min, and the reaction kinetics was discussed.

  2. The laboratory spectrum of acetaldehyde at 1 millimeter (230-325 GHz)

    NASA Technical Reports Server (NTRS)

    Barclay, W. L., Jr.; Anderson, M. A.; Ziurys, L. M.; Kleiner, I.; Hougen, J. T.

    1993-01-01

    The rotational spectrum of acetaldehyde (CH3CHO) in the frequency range 230-325 GHz has been measured in the laboratory using millimeter/submillimeter direct absorption spectroscopy. Over 250 transition frequencies are presented for this molecule for both A and E symmetry species in its ground (upsilon(sub t) = 0) and first excited (upsilon(sub t) = 1) torsional state, with experimental uncertainties of +/- 50 kHz. The data were fitted with a model involving an internal rotation potential function, which typically reproduces the measured frequencies to nu(sub obs) - nu(sub calc) less than or approximately 50 kHz for both ground and upsilon(sub t) = 1 state. These newly measured rest frequencies should aid in the identification of interstellar CH3CHO and in spectral line assignments for millimeter-band scans.

  3. Validation and Determination of the Contents of Acetaldehyde and Formaldehyde in Foods.

    PubMed

    Jeong, Hye-Seung; Chung, Hyun; Song, Sang-Hoon; Kim, Cho-Il; Lee, Joon-Goo; Kim, Young-Suk

    2015-09-01

    The aim of this study was to develop an efficient quantitative method for the determination of acetaldehyde (AA) and formaldehyde (FA) contents in solid and liquid food matrices. The determination of those compounds was validated and performed using gas chromatography-mass spectrometry combined by solid phase micro-extraction after derivatization with O-(2,3,4,5,6-pentafluoro-benzyl)-hydroxylamine hydrochloride. Validation was carried out in terms of limit of detection, limit of quantitation, linearity, precision, and recovery. Then their contents were analyzed in various food samples including 15 fruits, 22 milk products, 31 alcohol-free beverages, and 13 alcoholic beverages. The highest contents of AA and FA were determined in a white wine (40,607.02 ng/g) and an instant coffee (1,522.46 ng/g), respectively. PMID:26483886

  4. Theoretical study on the mechanism and kinetics of acetaldehyde and hydroperoxyl radical: An important atmospheric reaction

    NASA Astrophysics Data System (ADS)

    Farnia, Solaleh; Vahedpour, Morteza; Abedi, Mostafa; Farrokhpour, Hossein

    2013-09-01

    A systematic theoretical study was performed on the mechanism and kinetics of the atmospheric reaction of acetaldehyde (CH3CHO) and hydroperoxyl radical (HO2) in the gas phase. The DFT-B3LYP/6-311++G(3df,3pd) and CCSD(T)/6-311++G(d,p) methods were employed for calculations. Based on the calculations, this reaction leads to four different products through radical addition and hydrogen abstraction mechanisms which are very important in atmospheric and combustion chemistry. The favorable reaction paths begin with α-hydroxyethylperoxy radical, CH3CH(OO)OH, in a exothermic process and finally leads to the product P1 (CH3COOH + OH). The overall rate constants for favorite reaction paths have been calculated at different temperatures (200-2500 K).

  5. Validation and Determination of the Contents of Acetaldehyde and Formaldehyde in Foods

    PubMed Central

    Jeong, Hye-Seung; Chung, Hyun; Song, Sang-Hoon; Kim, Cho-Il; Lee, Joon-Goo

    2015-01-01

    The aim of this study was to develop an efficient quantitative method for the determination of acetaldehyde (AA) and formaldehyde (FA) contents in solid and liquid food matrices. The determination of those compounds was validated and performed using gas chromatography-mass spectrometry combined by solid phase micro-extraction after derivatization with O-(2,3,4,5,6-pentafluoro-benzyl)-hydroxylamine hydrochloride. Validation was carried out in terms of limit of detection, limit of quantitation, linearity, precision, and recovery. Then their contents were analyzed in various food samples including 15 fruits, 22 milk products, 31 alcohol-free beverages, and 13 alcoholic beverages. The highest contents of AA and FA were determined in a white wine (40,607.02 ng/g) and an instant coffee (1,522.46 ng/g), respectively. PMID:26483886

  6. Evaluation of acetone vapors toxicity on Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae) eggs.

    PubMed

    Pourmirza, Ali Asghr; Nasab, Fershteh Sadeghi; Zadeh, Abas Hossein

    2007-08-01

    The efficacy of acetone vapors against carefully aged eggs of Plodia interpunctella (Hubner) at 17+/-1 and 27+/-1 degrees C at different dosage levels of acetone over various exposure times was determined. Acetone was found to be toxic to Indian meal moth eggs. Considerable variation in the susceptibility of different age groups of eggs was apparent in the fiducial limits of the LD50 values. An inverse relationship between LD50 values and exposure times was observed in age groups of tested eggs. At 27+/-1 degrees C and 24 h exposure period, eggs aged 1-2 day-old were more tolerant to acetone than other age groups, followed by 0-1 day-old, 2-3 day-old and 3-4 day-old eggs. A similar pattern of susceptibility of eggs was observed at 72 h exposure. In all bioassays, eggs exposed to higher dosages of acetone developed at smaller rate. This was significant for the eggs, which were exposed to the highest dosage for 24 h. Increasing the temperature from 17+/-1 to 27+/-1 degrees C greatly increased the efficacy of acetone. At 27+/-1 degrees C eggs of P. interpunctella were killed by less than one-third of the dosage required for control at 17+/-1 degrees C. Acetone achieved 50% mortality with a dosage of 82.76 mg L(-1) in 1-2 day-old eggs at 27+/-1 degrees C. At this temperature hatching was retarded and greatly diminished when eggs aged 1-2 day-old were exposed to 80 mg L(-1) of acetone for the 24 h exposure period. There was no evidence of a hatch delay longer than the time spent under vapors for eggs exposed at 17+/-1 or 27+/-1 degrees C, indicating that some development must have occurred under fumigation.

  7. Upper Bound for Neutron Emission from Sonoluminescing Bubbles in Deuterated Acetone

    SciTech Connect

    Camara, C. G.; Putterman, S. J.; Hopkins, S. D.; Suslick, K. S.

    2007-02-09

    An experimental search for nuclear fusion inside imploding bubbles of degassed deuterated acetone at 0 degree sign C driven by a 15 atm sound field and seeded with a neutron generator reveals an upper bound that is a factor of 10 000 less than the signal reported by Taleyarkhan et al. The strength of our upper bound is limited by the weakness of sonoluminescence, which we ascribe to the relatively high vapor pressure of acetone.

  8. The Marangoni convection induced by acetone desorption from the falling soap film

    NASA Astrophysics Data System (ADS)

    Sha, Yong; Li, Zhangyun; Wang, Yongyi; Huang, Jiali

    2012-05-01

    By means of the falling soap film tunnel and the Schlieren optical method, the Marangoni convection were observed directly in the immediate interfacial neighborhood during the desorption process of acetone from the falling soap film. Moreover, the hydraulic characteristics of the falling soap film tunnel, the acetone concentration, the surface tension of the soap liquid and the mass transfer has been investigated in details through the experimental or theoretical method.

  9. KI-catalyzed α-acyloxylation of acetone with carboxylic acids.

    PubMed

    Wu, Ya-Dong; Huang, Bei; Zhang, Yue-Xin; Wang, Xiao-Xu; Dai, Jian-Jun; Xu, Jun; Xu, Hua-Jian

    2016-07-01

    The KI-catalyzed reaction of acetone with aromatic carboxylic acids is achieved, leading to α-acyloxycarbonyl compounds in good to excellent yields under mild reaction conditions. The present method exhibits good functional-group compatibility. Notably, this reaction system is even suitable for cinnamic acid, 3-phenylpropiolic acid and 4-phenylbutanoic acid. A kinetic isotope effect (KIE) study indicates that C-H cleavage of the acetone is the rate-limiting step in the catalytic cycle. PMID:27251323

  10. Malondialdehyde-acetaldehyde (MAA) adducted proteins bind to scavenger receptor A in airway epithelial cells.

    PubMed

    Berger, John P; Simet, Samantha M; DeVasure, Jane M; Boten, Jessica A; Sweeter, Jenea M; Kharbanda, Kusum K; Sisson, Joseph H; Wyatt, Todd A

    2014-08-01

    Co-exposure to cigarette smoke and ethanol generates malondialdehyde and acetaldehyde, which can subsequently lead to the formation of aldehyde-adducted proteins. We have previously shown that exposure of bronchial epithelial cells to malondialdehyde-acetaldehyde (MAA) adducted protein increases protein kinase C (PKC) activity and proinflammatory cytokine release. A specific ligand to scavenger receptor A (SRA), fucoidan, blocks this effect. We hypothesized that MAA-adducted protein binds to bronchial epithelial cells via SRA. Human bronchial epithelial cells (BEAS-2B) were exposed to MAA-adducted protein (either bovine serum albumin [BSA-MAA] or surfactant protein D [SPD-MAA]) and SRA examined using confocal microscopy, fluorescent activated cell sorting (FACS), and immunoprecipitation. Differentiated mouse tracheal epithelial cells (MTEC) cultured by air-liquid interface were assayed for MAA-stimulated PKC activity and keratinocyte-derived chemokine (KC) release. Specific cell surface membrane dye co-localized with upregulated SRA after exposure to MAA for 3-7 min and subsided by 20 min. Likewise, MAA-adducted protein co-localized to SRA from 3 to 7 min with a subsequent internalization of MAA by 10 min. These results were confirmed using FACS analysis and revealed a reduced mean fluorescence of SRA after 3 min. Furthermore, increased amounts of MAA-adducted protein could be detected by Western blot in immunoprecipitated SRA samples after 3 min treatment with MAA. MAA stimulated PKCε-mediated KC release in wild type, but not SRA knockout mice. These data demonstrate that aldehyde-adducted proteins in the lungs rapidly bind to SRA and internalize this receptor prior to the MAA-adducted protein stimulation of PKC-dependent inflammatory cytokine release in airway epithelium.

  11. Acetonitrile and N-Chloroacetamide Formation from the Reaction of Acetaldehyde and Monochloramine.

    PubMed

    Kimura, Susana Y; Vu, Trang Nha; Komaki, Yukako; Plewa, Michael J; Mariñas, Benito J

    2015-08-18

    Nitriles and amides are two classes of nitrogenous disinfection byproducts (DBPs) associated with chloramination that are more cytotoxic and genotoxic than regulated DBPs. Monochloramine reacts with acetaldehyde, a common ozone and free chlorine disinfection byproduct, to form 1-(chloroamino)ethanol. Equilibrium (K1) and forward and reverse rate (k1,k-1) constants for the reaction between initial reactants and 1-(chloroamino)ethanol were determined between 2 and 30 °C. Activation energies for k1 and k-1 were 3.04 and 45.2 kJ·mol(-1), respectively, and enthalpy change for K1 was -42.1 kJ·mol(-1). In parallel reactions, 1-(chloroamino)ethanol (1) slowly dehydrated (k2) to (chloroimino)ethane that further decomposed to acetonitrile and (2) was oxidized (k3) by monochloramine to produce N-chloroacetamide. Both reactions were acid/base catalyzed, and rate constants were characterized at 10, 18, and 25 °C. Modeling for drinking water distribution system conditions showed that N-chloroacetamide and acetonitrile concentrations were 5-9 times higher at pH 9.0 compared to 7.8. Furthermore, acetonitrile concentration was found to form 7-10 times higher than N-chloroacetamide under typical monochloramine and acetaldehyde concentrations. N-chloroacetamide cytotoxicity (LC50 = 1.78 × 10(-3) M) was comparable to dichloroacetamide and trichloroacetamide, but less potent than N,2-dichloroacetamide and chloroacetamide. While N-chloroacetamide was not found to be genotoxic, N,2-dichloroacetamide genotoxic potency (5.19 × 10(-3) M) was on the same order of magnitude as chloroacetamide and trichloroacetamide.

  12. A Diode Laser Study of the Catalytic Oxidation Dynamics of Acetaldehyde on Polycrystalline Platinum

    NASA Astrophysics Data System (ADS)

    Edington, Sean Coleman

    The catalytic oxidation of acetaldehyde on platinum was studied using a flow reactor equipped with a tunable diode laser absorption spectrometer and a quadrupole mass spectrometer. Reaction mixtures containing this molecule in varying proportion with oxygen and with argon as a carrier gas were flowed over a polycrystalline platinum mesh, which was resistively heated to different temperatures between 700 and 1000 K. The products of these reactions were monitored using mass spectrometry and the state-resolved spectra of CO 2 produced were collected using high-resolution tunable diode laser absorption spectroscopy. These data were analyzed to yield information about the dynamics of the reaction. Results indicate that production of CO and CO2 by this reaction proceeds via two distinct pathways. Acetaldehyde adsorbed on the surface decomposes to acetyl, which in turn decomposes CO and CHx. The adsorbed CO so prepared desorbs to yield the bulk of CO generated across all reaction conditions and also yields CO2 with a relatively deactivated asymmetric stretching mode under conditions of high temperature and low oxygen coverage. The acetyl-derived CHx dehydrogenates to yield surface carbon and H adatoms. Total oxidation of this surface carbon is the primary source of CO2 produced under all reaction conditions except those mentioned previously and is found to yield products with a preferentially excited asymmetric stretch. Combination of the CHx-derived H adatoms with surface oxygen drives the production of water by this reaction. During the course of the work described here, two notable improvements were made to our experimental apparatus. The first of these was the modification of the data acquisition process to significantly improve the signal-to-noise ratio achievable by our laser spectrometer with no increase in data collection time. The second was the development of data analysis software which significantly improved the efficiency and thoroughness of the process by

  13. Acetaldehyde as an underestimated risk factor for cancer development: role of genetics in ethanol metabolism

    PubMed Central

    Stickel, Felix

    2009-01-01

    Chronic ethanol consumption is a strong risk factor for the development of certain types of cancer including those of the upper aerodigestive tract, the liver, the large intestine and the female breast. Multiple mechanisms are involved in alcohol-mediated carcinogenesis. Among those the action of acetaldehyde (AA), the first metabolite of ethanol oxidation is of particular interest. AA is toxic, mutagenic and carcinogenic in animal experiments. AA binds to DNA and forms carcinogenic adducts. Direct evidence of the role of AA in alcohol-associated carcinogenesis derived from genetic linkage studies in alcoholics. Polymorphisms or mutations of genes coding for AA generation or detoxifying enzymes resulting in elevated AA concentrations are associated with increased cancer risk. Approximately 40% of Japanese, Koreans or Chinese carry the AA dehydrogenase 2*2 (ALDH2*2) allele in its heterozygous form. This allele codes for an ALDH2 enzyme with little activity leading to high AA concentrations after the consumption of even small amounts of alcohol. When individuals with this allele consume ethanol chronically, a significant increased risk for upper alimentary tract and colorectal cancer is noted. In Caucasians, alcohol dehydrogenase 1C*1 (ADH1C*1) allele encodes for an ADH isoenzyme which produces 2.5 times more AA than the corresponding allele ADH1C*2. In studies with moderate to high alcohol intake, ADH1C*1 allele frequency and rate of homozygosity was found to be significantly associated with an increased risk for cancer of the upper aerodigestive tract, the liver, the colon and the female breast. These studies underline the important role of acetaldehyde in ethanol-mediated carcinogenesis. PMID:19847467

  14. On apparent quantized transition-state thresholds in the photofragmentation of acetaldehyde

    NASA Astrophysics Data System (ADS)

    King, Rollin A.; Allen, Wesley D.; Schaefer, Henry F.

    2000-04-01

    Recent photofragmentation experiments have observed stepwise increases in the dissociation rate for CH3CHO (T1)→CH3 (X˜ 2A2″)+HCO (X˜ 2A') as a function of excitation energy. In accord with the Rice-Ramsperger-Kassel-Marcus (RRKM) form of transition-state theory, these steps were interpreted as corresponding to vibrational levels of the fragmentation transition state on the triplet surface. We have investigated this acetaldehyde dissociation using coupled cluster (CC) and density functional (DFT) methods with [C,O/H] atomic-orbital basis sets ranging in quality from [4s2p1d/2s1p] to [6s5p4d3f2g1h/5s4p3d2 f1g]. A high-level focal point analysis, along with harmonic force field computations, results in predictions of the dissociation energy, D0=1583 cm-1, and the association barrier height, V0*=3149 cm-1. With a basis set of triple-ζ plus double-polarization plus f(TZ2Pf ) quality, the DFT method UB3LYP and the CC method RCCSD predict barrier frequencies of 355i cm-1 and 516i cm-1, respectively, while the empirical value inferred from RRKM models is only 60i cm-1. The RRKM-derived frequencies for the degrees of freedom orthogonal to the reaction path are more reasonable but still not in convincing agreement with electronic structure theory. Thus, while the experimental steps in the dissociation rate of acetaldehyde (as well as ketene) have yet to be satisfactorily explained, proven ab initio methods provide strong evidence that simple RRKM fits to the k(E) profile provide misleading vibrational frequencies of the transition state on the corresponding triplet potential energy surface.

  15. Diffusion behaviour of the acetaldehyde scavenger 2-aminobenzamide in polyethylene terephthalate for beverage bottles.

    PubMed

    Franz, Roland; Gmeiner, Margit; Gruner, Anita; Kemmer, Diana; Welle, Frank

    2016-01-01

    Polyethylene terephthalate (PET) bottles are widely used as packaging material for natural mineral water. However, trace levels of acetaldehyde can migrate into natural mineral water during the shelf life and might influence the taste of the PET bottled water. 2-Aminobenzamide is widely used during PET bottle production as a scavenging agent for acetaldehyde. The aim of this study was the determination of the migration kinetics of 2-aminobenzamide into natural mineral water as well as into 20% ethanol. From the migration kinetics, the diffusion coefficients of 2-aminobenzamide in PET at 23 and 40°C were determined to be 4.2 × 10(-)(16) and 4.2 × 10(-)(15) cm(2) s(-1), respectively. The diffusion coefficient for 20% ethanol at 40°C was determined to be 7.7 × 10(-)(15) cm(2) s(-1), which indicates that 20% ethanol is causing swelling of the PET polymer. From a comparison of migration values between 23 and 40°C, acceleration factors of 9.7 when using water as contact medium and 18.1 for 20% ethanol as simulant can be derived for definition of appropriate accelerated test conditions at 40°C. The European Union regulatory acceleration test based on 80 kJ mol(-1) as conservative activation energy overestimates the experimentally determined acceleration rates by a factor of 1.6 and 3.1, respectively. PMID:26666986

  16. Mechanism of anaerobic ether cleavage: conversion of 2-phenoxyethanol to phenol and acetaldehyde by Acetobacterium sp.

    PubMed

    Speranza, Giovanna; Mueller, Britta; Orlandi, Maximilian; Morelli, Carlo F; Manitto, Paolo; Schink, Bernhard

    2002-04-01

    2-Phenoxyethanol is converted into phenol and acetate by a strictly anaerobic Gram-positive bacterium, Acetobacterium strain LuPhet1. Acetate results from oxidation of acetaldehyde that is the early product of the biodegradation process (Frings, J., and Schink, B. (1994) Arch. Microbiol. 162, 199-204). Feeding experiments with resting cell suspensions and 2-phenoxyethanol bearing two deuterium atoms at either carbon of the glycolic moiety as substrate demonstrated that the carbonyl group of the acetate derives from the alcoholic function and the methyl group derives from the adjacent carbon. A concomitant migration of a deuterium atom from C-1 to C-2 was observed. These findings were confirmed by NMR analysis of the acetate obtained by fermentation of 2-phenoxy-[2-(13)C,1-(2)H(2)]ethanol, 2-phenoxy-[1-(13)C,1-(2)H(2)]ethanol, and 2-phenoxy-[1,2-(13)C(2),1-(2)H(2)]ethanol. During the course of the biotransformation process, the molecular integrity of the glycolic unit was completely retained, no loss of the migrating deuterium occurred by exchange with the medium, and the 1,2-deuterium shift was intramolecular. A diol dehydratase-like mechanism could explain the enzymatic cleavage of the ether bond of 2-phenoxyethanol, provided that an intramolecular H/OC(6)H(5) exchange is assumed, giving rise to the hemiacetal precursor of acetaldehyde. However, an alternative mechanism is proposed that is supported by the well recognized propensity of alpha-hydroxyradical and of its conjugate base (ketyl anion) to eliminate a beta-positioned leaving group.

  17. Diffusion behaviour of the acetaldehyde scavenger 2-aminobenzamide in polyethylene terephthalate for beverage bottles

    PubMed Central

    Franz, Roland; Gmeiner, Margit; Gruner, Anita; Kemmer, Diana; Welle, Frank

    2016-01-01

    ABSTRACT Polyethylene terephthalate (PET) bottles are widely used as packaging material for natural mineral water. However, trace levels of acetaldehyde can migrate into natural mineral water during the shelf life and might influence the taste of the PET bottled water. 2-Aminobenzamide is widely used during PET bottle production as a scavenging agent for acetaldehyde. The aim of this study was the determination of the migration kinetics of 2-aminobenzamide into natural mineral water as well as into 20% ethanol. From the migration kinetics, the diffusion coefficients of 2-aminobenzamide in PET at 23 and 40°C were determined to be 4.2 × 10− 16 and 4.2 × 10− 15 cm2 s–1, respectively. The diffusion coefficient for 20% ethanol at 40°C was determined to be 7.7 × 10− 15 cm2 s–1, which indicates that 20% ethanol is causing swelling of the PET polymer. From a comparison of migration values between 23 and 40°C, acceleration factors of 9.7 when using water as contact medium and 18.1 for 20% ethanol as simulant can be derived for definition of appropriate accelerated test conditions at 40°C. The European Union regulatory acceleration test based on 80 kJ mol–1 as conservative activation energy overestimates the experimentally determined acceleration rates by a factor of 1.6 and 3.1, respectively. PMID:26666986

  18. Metabolic methanol: molecular pathways and physiological roles.

    PubMed

    Dorokhov, Yuri L; Shindyapina, Anastasia V; Sheshukova, Ekaterina V; Komarova, Tatiana V

    2015-04-01

    Methanol has been historically considered an exogenous product that leads only to pathological changes in the human body when consumed. However, in normal, healthy individuals, methanol and its short-lived oxidized product, formaldehyde, are naturally occurring compounds whose functions and origins have received limited attention. There are several sources of human physiological methanol. Fruits, vegetables, and alcoholic beverages are likely the main sources of exogenous methanol in the healthy human body. Metabolic methanol may occur as a result of fermentation by gut bacteria and metabolic processes involving S-adenosyl methionine. Regardless of its source, low levels of methanol in the body are maintained by physiological and metabolic clearance mechanisms. Although human blood contains small amounts of methanol and formaldehyde, the content of these molecules increases sharply after receiving even methanol-free ethanol, indicating an endogenous source of the metabolic methanol present at low levels in the blood regulated by a cluster of genes. Recent studies of the pathogenesis of neurological disorders indicate metabolic formaldehyde as a putative causative agent. The detection of increased formaldehyde content in the blood of both neurological patients and the elderly indicates the important role of genetic and biochemical mechanisms of maintaining low levels of methanol and formaldehyde.

  19. Acetone and isopropanol in ruminal fluid and feces of lactating dairy cows.

    PubMed

    Sato, Hiroshi; Shiogama, Yumiko

    2010-03-01

    Acetone and its metabolite isopropanol are produced by gut microbes as well as by the host's metabolism. To evaluate the production of acetone and isopropanol in alimentary tracts, a total of 80 pair-samples of feces and ruminal fluid were taken in lactating dairy cows that had been fed silage-containing diets. Acetone and isopropanol were analyzed, together with ethanol and volatile fatty acids (VFAs). Isopropanol was detected in 57 fecal and all the ruminal samples; however, the ruminal isopropanol and ethanol concentrations were distinctly lower than those in the feces. Acetone was detected in 13 fecal and 53 ruminal samples; however, there was no significant difference in acetone concentrations between the feces and the ruminal fluid. The group with higher fecal isopropanol concentration showed higher fecal proportions of acetate accompanied by low proportion of minor VFA, which consisted of isobutyrate and iso- and n-valerate. In the group with higher ruminal isopropanol concentration, ethanol concentration was higher; the ruminal VFA profiles showed only a negligible difference. Fecal and ruminal ethanol concentrations were not affected by feed ethanol. Thus, the colon showed an accelerated alcoholic fermentation compared with the rumen of dairy cows; however, acetone was present at higher frequency in the rumen than in the feces.

  20. Fermentation and genomic analysis of acetone-uncoupled butanol production by Clostridium tetanomorphum.

    PubMed

    Gong, Fuyu; Bao, Guanhui; Zhao, Chunhua; Zhang, Yanping; Li, Yin; Dong, Hongjun

    2016-02-01

    In typical acetone-butanol-ethanol (ABE) fermentation, acetone is the main by-product (50 % of butanol mass) of butanol production, resulting in a low yield of butanol. It is known that some Clostridium tetanomorphum strains are able to produce butanol without acetone in nature. Here, we described that C. tetanomorphum strain DSM665 can produce 4.16 g/L butanol and 4.98 g/L ethanol at pH 6.0, and 9.81 g/L butanol and 1.01 g/L ethanol when adding 1 mM methyl viologen. Butyrate and acetate could be reassimilated and no acetone was produced. Further analysis indicated that the activity of the acetate/butyrate:acetoacetyl-CoA transferase responsible for acetone production is lost in C. tetanomorphum DSM665. The genome of C. tetanomorphum DSM665 was sequenced and deposited in DDBJ, EMBL, and GenBank under the accession no. APJS00000000. Sequence analysis indicated that there are no typical genes (ctfA/B and adc) that are typically parts of an acetone synthesis pathway in C. tetanomorphum DSM665. This work provides new insights in the mechanism of clostridial butanol production and should prove useful for the design of a high-butanol-producing strain.

  1. Adsorption study of acetone on acid-doped ice surfaces between 203 and 233 K.

    PubMed

    Journet, E; Le Calvé, S; Mirabel, Ph

    2005-07-28

    Adsorption studies of acetone on pure ice surfaces obtained by water freezing or deposition or on frozen ice surfaces doped either with HNO3 or H2SO4 have been performed using a coated wall flow tube coupled to a mass spectrometric detection. The experiments were conducted over the temperature range 203-233 K and freezing solutions containing either H2SO4 (0.2 N) or HNO3 (0.2-3 N). Adsorption of acetone on these ice surfaces was always found to be totally reversible whatever were the experimental conditions. The number of acetone molecules adsorbed per ice surface unit N was conventionally plotted as a function of acetone concentration in the gas phase. For the same conditions, the amount of acetone molecules adsorbed on pure ice obtained by deposition are about 3-4 times higher than those measured on frozen ice films, H2SO4-doped ice surfaces lead to results comparable to those obtained on pure ice. On the contrary, N increases largely with increasing concentrations of nitric acid in ice surfaces, up to about 300 times under our experimental conditions and for temperatures ranging between 213 and 233 K. Finally, the results are discussed and used to reestimate the partitioning of acetone between the ice and gas phases in clouds of the upper troposphere.

  2. Design and Operation of an Electrochemical Methanol Concentration Sensor for Direct Methanol Fuel Cell Systems

    NASA Technical Reports Server (NTRS)

    Narayanan, S. R.; Valdez, T. I.; Chun, W.

    2000-01-01

    The development of a 150-Watt packaged power source based on liquid feed direct methanol fuel cells is being pursued currently at the Jet propulsion Laboratory for defense applications. In our studies we find that the concentration of methanol in the fuel circulation loop affects the electrical performance and efficiency the direct methanol fuel cell systems significantly. The practical operation of direct methanol fuel cell systems, therefore, requires accurate monitoring and control of methanol concentration. The present paper reports on the principle and demonstration of an in-house developed electrochemical sensor suitable for direct methanol fuel cell systems.

  3. Recent Studies on Methanol Crossover in Liquid-Feed Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Narayanan, S. R.

    2000-01-01

    In this work, the effects of methanol crossover and airflow rates on the cathode potential of an operating direct methanol fuel cell are explored. Techniques for quantifying methanol crossover in a fuel cell and for separating the electrical performance of each electrode in a fuel cell are discussed. The effect of methanol concentration on cathode potential has been determined to be significant. The cathode is found to be mass transfer limited when operating on low flow rate air and high concentrations of methanol. Improvements in cathode structure and operation at low methanol concentration have been shown to result in improved cell performance.

  4. Towards a methanol economy based on homogeneous catalysis: methanol to H2 and CO2 to methanol.

    PubMed

    Alberico, E; Nielsen, M

    2015-04-21

    The possibility to implement both the exhaustive dehydrogenation of aqueous methanol to hydrogen and CO2 and the reverse reaction, the hydrogenation of CO2 to methanol and water, may pave the way to a methanol based economy as part of a promising renewable energy system. Recently, homogeneous catalytic systems have been reported which are able to promote either one or the other of the two reactions under mild conditions. Here, we review and discuss these developments.

  5. Development of an LC-MS/MS method for studying migration characteristics of acetaldehyde in polyethylene terephthalate (PET)-packed mineral water.

    PubMed

    Baumjohann, Nina; Harms, Diedrich

    2015-01-01

    During storage, acetaldehyde migration from polyethylene terephthalate (PET) bottles can affect the quality of mineral water even in the low µg l(-1) range negatively, as it features a fruity or plastic-like off-flavour. For a sensitive and fast analysis of acetaldehyde in mineral water, a new analysis method of 2,4-dinitrophenylhydrazine (DNPH) derivatisation followed by HPLC-electrospray tandem mass spectrometry (ESI-MS/MS) was developed. Acetaldehyde was directly derivatised in the mineral water sample avoiding extraction and/or pre-concentration steps and then analysed by reversed-phase HPLC-ESI-MS/MS using multiple reaction monitoring mode (MRM). Along with method development, the optimum molar excess of DNPH in contrast to acetaldehyde was studied for the mineral water matrix, because no specific and robust data were yet available for this critical parameter. Best results were obtained by using a calibration via the derivatisation reaction. Without any analyte enrichment or extraction, an LOD of 0.5 µg l(-1) and an LOQ of 1.9 µg l(-1) were achieved. Using the developed method, mineral water samples packed in PET bottles from Germany were analysed and the correlation between the acetaldehyde concentration and other characteristics of the samples was evaluated illustrating the applicability of the method. Besides a relationship between bottle size and CO2 content of the mineral water and acetaldehyde migration, a correlation with acetaldehyde migration and the material composition of the bottle, e.g. recycled PET, was noted. Investigating the light influence on the acetaldehyde migration with a newly developed, reproducible light exposure setup, a significant increase of the acetaldehyde concentration in carbonated mineral water samples was observed. PMID:26258902

  6. Methods of conditioning direct methanol fuel cells

    DOEpatents

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

    Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

  7. Propane Clathrate Hydrate Formation Accelerated by Methanol.

    PubMed

    Amtawong, Jaruwan; Guo, Jin; Hale, Jared S; Sengupta, Suvrajit; Fleischer, Everly B; Martin, Rachel W; Janda, Kenneth C

    2016-07-01

    The role of methanol as both an inhibitor and a catalyst for the formation of clathrate hydrates (CHs) has been a topic of intense study. We report a new quantitative study of the kinetics of propane CH formation at 253 K from the reaction of propane gas with <75 μm ice particles that have been doped with varying amounts of methanol. We find that methanol significantly accelerates the formation reaction with quite small doping quantities. Even for only 1 methanol molecule per 10 000 water molecules, the maximum uptake rate of propane into CHs is enhanced and the initiation pressure is reduced. These results enable more efficient production of CHs for gas storage. This remarkable acceleration of the CH formation reaction by small quantities of methanol may place constraints on the mechanism of the inhibition effect observed under other conditions, usually employing much larger quantities of methanol. PMID:27275862

  8. A novel process for methanol synthesis

    SciTech Connect

    Tierney, J.W.; Wender, I.

    1992-01-28

    A bench-scale reactor is being used to conduct studies of the conversion of synthesis gas to methanol by a novel process. In previous reports, we provided evidence for a two step reaction in series: the carbonylation of methanol to methyl formate taking place in a non-equilibrium region in the vicinity of the copper chromite surface, and the hydrogenolysis of methyl formate to methanol taking place on the surface of the copper chromite. The synergism between the two catalysts enhances the rate of methanol formation. In this quarter, we tested several copper chromites (with different surface areas and stabilizing agents) on the rate of methanol synthesis. It seems likely that pore diffusion limitations control the hydrogenolysis reaction since the rate of methanol formation is proportional to the square root of the copper chromite surface area. Elemental analyses using Inductively Coupled Plasma analysis and pore size distribution analysis of copper chromite were carried out.

  9. Asymptomatic blood methanol in emergency room patients.

    PubMed

    Wargotz, E S; Werner, M

    1987-06-01

    Over a four-month period, methanol was found in the blood of 18 patients among 687 sequential emergency room admissions screened for alcohols by gas chromatography. In the patients with positive results, blood ethanol ranged from 6 to 570 mg/dL (1.3-123.7 mmol/L), blood methanol from 2.3 to 4.0 mg/dL (0.72-1.25 mmol/L). Methanol exposure during preparation of the sampling site or in the course of specimen handling, ingestion of denatured alcohol, as well as methanol production from the metabolism of aspartame are ruled out as causes for these findings. The authors conclude that endogenous methanol production is the probable major cause, while methanol as a fermentation congener may be a contributory minor cause.

  10. Acetone and Water on TiO₂(110): H/D Exchange

    SciTech Connect

    Henderson, Michael A.

    2005-04-12

    Isotopic H/D exchange between coadsorbed acetone and water on the TiO?(110) surface was examined using temperature programmed desorption (TPD) as a function of coverage and two surface pretreatments (oxidation and reduction). Coadsorbed acetone and water interact repulsively on reduced TiO?(110) based on results from the companion paper to this study, with water exerting a greater influence in destabilizing acetone and acetone having only a nominal influence on water. Despite the repulsive interaction between these coadsorbates, about 0.02 ML of a 1 ML d6-acetone on the reduced surface exhibits H/D exchange with coadsorbed water, with the exchange occurring exclusively in the high temperature region of the d?-acetone TPD spectrum at {approx}340 K. The effect was confirmed with combinations of d?-acetone and D?O. The extent of exchange decreased on the reduced surface with water coverages above {approx}0.3 ML due to the ability of water to displace coadsorbed acetone from first layer sites to the multilayer. In contrast, the extent of exchange increased by a factor of 3 when the surface was pre-oxidized prior to coadsorption. In this case, there was no evidence for the negative influence of high water coverages on the extent of H/D exchange. Comparison of the TPD spectra from the exchange products (either d?- or d?-acetone depending on the coadsorption pairing) suggests that, in addition to the 340 K exchange process seen on the reduced surface, a second exchange process was observed on the oxidized surface at {approx}390 K. In both cases (oxidized and reduced), desorption of the H/D exchange products appeared to be reaction limited and to involve the influence of OH/OD groups (or water formed during recombinative desorption of OH/OD groups) instead of molecularly adsorbed water. The 340 K exchange process is assigned to reaction at step sites and the 390 K exchange process is attributed to the influence of oxygen adatoms deposited during surface oxidation. The H

  11. Method of steam reforming methanol to hydrogen

    DOEpatents

    Beshty, Bahjat S.

    1990-01-01

    The production of hydrogen by the catalyzed steam reforming of methanol is accomplished using a reformer of greatly reduced size and cost wherein a mixture of water and methanol is superheated to the gaseous state at temperatures of about 800.degree. to about 1,100.degree. F. and then fed to a reformer in direct contact with the catalyst bed contained therein, whereby the heat for the endothermic steam reforming reaction is derived directly from the superheated steam/methanol mixture.

  12. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

  13. Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

    PubMed

    Quirk, Emma; Doggett, Adrian; Bretnall, Alison

    2014-08-01

    Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA.

  14. Bioinduced Room-Temperature Methanol Reforming.

    PubMed

    Heim, Leo E; Thiel, Daniel; Gedig, Christian; Deska, Jan; Prechtl, Martin H G

    2015-08-24

    Imitating nature's approach in nucleophile-activated formaldehyde dehydrogenation, air-stable ruthenium complexes proved to be exquisite catalysts for the dehydrogenation of formaldehyde hydrate as well as for the transfer hydrogenation to unsaturated organic substrates at loadings as low as 0.5 mol %. Concatenation of the chemical hydrogen-fixation route with an oxidase-mediated activation of methanol gives an artificial methylotrophic in vitro metabolism providing methanol-derived reduction equivalents for synthetic hydrogenation purposes. Moreover, for the first time methanol reforming at room temperature was achieved on the basis of this bioinduced dehydrogenation path delivering hydrogen gas from aqueous methanol.

  15. Methanol-Resistant Oxygen-Reduction Catalysts for Direct Methanol Fuel Cells

    NASA Astrophysics Data System (ADS)

    Shukla, A. K.; Raman, R. K.

    2003-08-01

    Methanol oxidation in the cathode compartment of the fuel cell, which occurs during the oxygen-reduction reaction on Pt-based cathodes, constitutes a significant performance loss in the direct methanol fuel cells. Over the past decade, four types of methanol-resistant oxygen-reduction catalysts have been developed to circumvent this problem. Among these, transition-metal chalcogenides, and in particular RuSe, have shown effective selectivity to oxygen-reduction reaction in the presence of methanol. These catalysts not only can enhance the performance of the conventional direct methanol fuel cells but also could provide a route to develop mixed-reactants direct methanol fuel cells, which could be highly cost-effective in comparison with the conventional direct methanol fuel cells. This article is a brief update on the preparation, characterization, and implications of methanol-resistant oxygen-reduction catalysts.

  16. Selective clean-up applicable to aqueous acetone extracts for the determination of carbendazim and thiabendazole in fruits and vegetables by high-performance liquid chromatography with UV detection.

    PubMed

    Di Muccio, A; Girolimetti, S; Attard Barbini, D; Pelosi, P; Generali, T; Vergori, L; De Merulis, G; Leonelli, A; Stefanelli, P

    1999-02-12

    Fungicide residues in vegetables (benomyl, carbendazim, thiabendazole) are analyzed through a clean-up procedure that uses a portion of the aqueous acetone extract prepared for multiresidue methodology. A portion of the aqueous acetone extract (equivalent to 5 g of vegetables) is loaded onto an Extrelut-20 cartridge (the cartridge is filled with a coarse, large-pore diatomaceous material). Then, acetone is partially removed by an upward stream of nitrogen at 2l/min for 30 min. Benzimidazolic fungicides are recovered by percolating the cartridge with 100 ml of 0.1 M phosphoric acid solution, which also serves to convert benomyl to carbendazim. The percolating acid solution is drained on-line through a strong cation-exchange (SCX) solid-phase extraction cartridge with the aid of a slight vacuum. Benzimidazolic fungicides are retained on the SCX cartridge. The phosphoric acid solution is discarded together with the washings of the SCX cartridge, i.e., water followed by methanol-water (75:25), that remove unwanted coextractives. Finally, benzimidazolic fungicides are recovered by eluting the SCX cartridge with methanol-ammonium formate buffer (75:25). The final extract is then analyzed by reversed-phase HPLC with UV detection. Recoveries from crops such as apples, lettuce, strawberries and citrus fruits are generally greater than 80% and no interferences were observed. The clean-up is simple and straightforward, requires only disposable items, water solutions and a few milliliters of solvent and a minimum number of manipulations, and does not require concentration steps or electrical equipment. PMID:10074700

  17. Dark- and photoreactions of ethanol and acetaldehyde over TiO{sub 2}/carbon molecular sieve fibers

    SciTech Connect

    Reztsova, T.; Chang, C.H.; Idriss, H.; Koresh, J.

    1999-07-01

    TiO{sub 2} has been synthesized within the pores of carbon molecular sieve fibers (CMSF) in order to grow particles of quantum size. TiO{sub 2}/CMSF characteristics were followed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV-vis diffuse reflectance. XPS showed that all Ti cations are in a +4 oxidation state. The reduction profile of Ti cations (made by preferential O anion removal due to Ar{sup +} sputtering), as evidenced by Ti{sup +x}/Ti{sup +4} cations, is very similar to that already observed for well-defined TiO{sub 2} surfaces. The absence of XRD pattern indicated that TiO{sub 2} particles are in an amorphous form. UV-vis diffuse reflectance showed a considerably blue shift ({Delta}E = 0.6--0.7 eV) of the band gap of TiO{sub 2}/CMSF when compared to TiO{sub 2} (anatase). This shift translates an average particle radius of 15 {+-} 2 {angstrom}. Larger TiO{sub 2} particles, outside the CMSF nanopores, are, however, observed by TEM. Dark- and photoreactions of ethanol and acetaldehyde have been investigated over TiO{sub 2}/CMSF by steady state kinetics and temperature programmed desorption in UHV conditions, as well as in batch conditions at atmospheric pressure. UHV-steady state ethanol reactions have shown eightfold increase in the reaction rate at 573 K in the presence of UV when compared to dark reactions at the same temperatures. The rate constants ratio k{sub 2}K{sub 2}/k{sub 1}K{sub 1}, for the photoreactions of ethanol, is ca. 40 times higher for TiO{sub 2}/CMSF than for TiO{sub 2} (powder) indicating the high selectivity of the former toward total conversion of ethanol to CO{sub 2} with minor accumulation of acetaldehyde (k{sub 1}K{sub 1} and k{sub 2}K{sub 2} are the rate constants for ethanol to acetaldehyde and acetaldehyde to CO{sub 2}, respectively). Evidence of C-C bond dissociation is given by formaldehyde desorption during UV-acetaldehyde-TPD over TiO{sub 2}/CMSF under UHV conditions. Moreover, UV-acetaldehyde

  18. Biogeochemical Cycle of Methanol in Anoxic Deep-Sea Sediments

    PubMed Central

    Yanagawa, Katsunori; Tani, Atsushi; Yamamoto, Naoya; Hachikubo, Akihiro; Kano, Akihiro; Matsumoto, Ryo; Suzuki, Yohey

    2016-01-01

    The biological flux and lifetime of methanol in anoxic marine sediments are largely unknown. We herein reported, for the first time, quantitative methanol removal rates in subsurface sediments. Anaerobic incubation experiments with radiotracers showed high rates of microbial methanol consumption. Notably, methanol oxidation to CO2 surpassed methanol assimilation and methanogenesis from CO2/H2 and methanol. Nevertheless, a significant decrease in methanol was not observed after the incubation, and this was attributed to the microbial production of methanol in parallel with its consumption. These results suggest that microbial reactions play an important role in the sources and sinks of methanol in subseafloor sediments. PMID:27301420

  19. Acetone laser-induced fluorescence for temperature and multiparameter imaging in gaseous flows

    NASA Astrophysics Data System (ADS)

    Thurber, Mark Clinton

    1999-10-01

    Acetone (CH3COCH3) is an excellent tracer for planar laser-induced fluorescence (PLIF) imaging in gaseous flows due to its low toxicity, high vapor pressure, and accessible absorption (225-320 nm) and fluorescence (350-550 nm) features. A fluorescence yield limited by rapid intersystem crossing reduces the importance of collisional effects. Since the initial work of Lozano (1992), acetone PLIF has been applied with quantitative success in studies of gas-phase mixing under isothermal, isobaric conditions. More recently, improved understanding of acetone fluorescence dependences has opened up possibilities for new diagnostics across a range of conditions. Through modeling and experimental measurement of fluorescence dependences, the current work aims to make existing diagnostics more quantitative and to allow development of new diagnostics for other parameters, in particular temperature. To this end, temperature dependences of fluorescence are measured at excitation wavelengths across the acetone absorption spectrum. Fluorescence per unit acetone mole fraction decreases significantly with increasing temperature for short wavelengths (248 and 266 nm) and weakly (308 nm) or not at all (320 nm) for longer wavelengths. These effects are related to changes in absorption cross-section and fluorescence yield with temperature. A quantitative multistep decay model of fluorescence yield explains the observed temperature and wavelength functionalities and also predicts effects of pressure and composition. Measurements of pressure and composition dependences of acetone fluorescence between 0.5 and 16 atm, with excitation at 248, 266, and 308 nm, are found to agree with model predictions. A mild fluorescence quenching effect of oxygen is observed, which the model, with slight modification, can explain as well. Temperature and multiparameter imaging diagnostics are made possible by the improved understanding of acetone photophysical behavior. Excitation at 248 or 266 nm is

  20. Breath acetone monitoring by portable Si:WO3 gas sensors

    PubMed Central

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

    2013-01-01

    Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (~20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

  1. Recovery and reuse of spent acetone via a mobile solvent recovery unit

    SciTech Connect

    Townsend, M.W.

    1996-11-01

    The Monsanto Chemical Company operates a plastics and resins plant located in Addyston, Ohio. The process equipment requires routine rinsing with technical grade acetone between batches. Due to the volumes of spent acetone generated and the associated RCRA hazardous waste regulations, the plant sought to recycle and reuse the acetone to reduce the purchase cost of virgin acetone and the cost of spent acetone disposal. One of the first options explored was package unit distillation units. The cost of these units was in the $20--$30,000 range in 1989 dollars. Even though the cost of a package unit was not deemed unreasonable, there were additional costs and concerns that led to elimination of this option. The unit would have required additional manpower to operate and maintain, i.e., at least a fraction of an operator and mechanic. For plant safety reasons, it was desired to operate this package unit outside the production building, thus construction of an outbuilding would have added to the expense of the project. Additionally, there were concerns of package unit reliability. During this evaluation, tractor-trailer mounted distillation units were discovered. The portable units were equipped with either thin-film evaporator technology capable of processing 240 to 480 gallons per hour, or pot still (batch) distillation technology capable of rates from 120 to 240 gallons per hour. Both units were constructed of stainless steel.

  2. Field Demonstration of Acetone Pretreatment and Composting of Particulate-TNT-Contaminated Soil

    SciTech Connect

    Radtke, Corey William; Smith, D.; Owen, S.; Roberto, Francisco Figueroa

    2002-02-01

    Solid fragments of explosives in soil are common in explosives testing and training areas. In this study we initially sieved the upper 6 in of contaminated soil through a 3-mm mesh, and found 2, 4, 6-trinitrotoluene (TNT) fragments. These contributed to an estimated concentration of 1.7 kg per cubic yard soil, or for 2000 ppm TNT in the soil. Most of the fragments ranged 4 mm to 10 mm diameter in size, but explosives particles weighing up to 56 g (about 4 cm diameter) were frequently observed. An acetone pretreatment/composting system was then demonstrated at field scale. The amount of acetone required for a TNT-dissolving slurry process was controlled by the viscosity of the soil/acetone mix rather than the TNT dissolution rate. The amount needed was estimated at about 55 gallons acetone per cubic yard soil. Smaller, 5- to 10-mm-diameter fragments went into solution in less than 15 min at a mixer speed of 36 rpm, with a minimum of 2 g TNT going into solution per 30 min for the larger chunks. The slurries were than mixed with compost starting materials and composted in a vented 1 yd3 container. After 34 days incubation time TNT was below the site-specific regulatory threshold of 44 ppm. TNT metabolites and acetone were also below their regulatory thresholds established for the site.

  3. Dielectric barrier discharge micro-plasma emission spectrometry for the detection of acetone in exhaled breath.

    PubMed

    Yang, Ting; Gao, Dong-Xue; Yu, Yong-Liang; Chen, Ming-Li; Wang, Jian-Hua

    2016-01-01

    Acetone is a predominant volatile organic compound (VOC) in the exhaled breath and a promising biomarker for diabetes and ketoacidosis. A non-thermal micro-plasma generated in a planar dielectric barrier discharge (DBD) is used as a radiation source for the excitation of gaseous acetone followed by its quantification with optical emission spectrometry (OES). Gaseous acetone can be directly sampled, while liquid acetone is evaporated by heated tungsten coil and then introduced into the DBD micro-plasma by a helium carrier flow for performing optical emission and detection at a 519 nm emission line. In the present study, the exhaled breath is collected and transferred into aqueous medium for sampling. With a sampling volume of 7 μL in a micro-drop, a linear range of 40-1600 mg L(-1) is obtained along with a detection limit of 44 ng and a precision of 5.7% RSD. The present system is successfully applied to the determination of breath acetone for both diabetic patients and healthy volunteers.

  4. Study of the exhaled acetone in type 1 diabetes using quantum cascade laser spectroscopy.

    PubMed

    Reyes-Reyes, Adonis; Horsten, Roland C; Urbach, H Paul; Bhattacharya, Nandini

    2015-01-01

    The acetone concentration exhaled in the breath of three type 1 diabetes patients (two minors and one adult) and one healthy volunteer is studied using a quantum cascade laser-based spectroscopic system. Using the acetone signature between 1150 and 1250 cm(-1) and a multiline fitting method, the concentration variations on the order of parts per billion by volume were measured. Blood glucose and ketone concentrations in blood measurements were performed simultaneously to study their relation with acetone in exhaled breath. We focus on personalized studies to better understand the role of acetone in diabetes. For each volunteer, we performed a series of measurements over a period of time, including overnight fastings of 11 ± 1 h and during ketosis-hyperglycemia events for the minors. Our results highlight the importance of performing personalized studies because the response of the minors to the presence of ketosis was consistent but unique for each individual. Also, our results emphasize the need for performing more studies with T1D minors, because the acetone concentration in the breath of the minors differs, with respect to those reported in the literature, which are based on adults.

  5. Breath acetone monitoring by portable Si:WO3 gas sensors.

    PubMed

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E

    2012-08-13

    Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO(3) nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20ppb) with short response (10-15s) and recovery times (35-70s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80-90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

  6. Photochemical degradation of citrate buffers leads to covalent acetonation of recombinant protein therapeutics

    PubMed Central

    Valliere-Douglass, John F; Connell-Crowley, Lisa; Jensen, Randy; Schnier, Paul D; Trilisky, Egor; Leith, Matt; Follstad, Brian D; Kerr, Jennifer; Lewis, Nathan; Vunnum, Suresh; Treuheit, Michael J; Balland, Alain; Wallace, Alison

    2010-01-01

    Novel acetone and aldimine covalent adducts were identified on the N-termini and lysine side chains of recombinant monoclonal antibodies. Photochemical degradation of citrate buffers, in the presence of trace levels of iron, is demonstrated as the source of these modifications. The link between degradation of citrate and the observed protein modifications was conclusively established by tracking the citrate decomposition products and protein adducts resulting from photochemical degradation of isotope labeled 13C citrate by mass spectrometry. The structure of the acetone modification was determined by nuclear magnetic resonance (NMR) spectroscopy on modified–free glycine and found to correspond to acetone linked to the N-terminus of the amino acid through a methyl carbon. Results from mass spectrometric fragmentation of glycine modified with an acetone adduct derived from 13C labeled citrate indicated that the three central carbons of citrate are incorporated onto protein amines in the presence of iron and light. While citrate is known to stoichiometrically decompose to acetone and CO2 through various intermediates in photochemical systems, it has never been shown to be a causative agent in protein carbonylation. Our results point to a previously unknown source for the generation of reactive carbonyl species. This work also highlights the potential deleterious impact of trace metals on recombinant protein therapeutics formulated in citrate buffers. PMID:20836085

  7. Vibrational Excitation of Both Products of the Reaction of CN Radicals with Acetone in Solution

    PubMed Central

    2015-01-01

    Transient electronic and vibrational absorption spectroscopy unravel the mechanisms and dynamics of bimolecular reactions of CN radicals with acetone in deuterated chloroform solutions. The CN radicals are produced by ultrafast ultraviolet photolysis of dissolved ICN. Two reactive forms of CN radicals are distinguished by their electronic absorption bands: “free” (uncomplexed) CN radicals, and “solvated” CN radicals that are complexed with solvent molecules. The lifetimes of the free CN radicals are limited to a few picoseconds following their photolytic production because of geminate recombination to ICN and INC, complexation with CDCl3 molecules, and reaction with acetone. The acetone reaction occurs with a rate coefficient of (8.0 ± 0.5) × 1010 M–1 s–1 and transient vibrational spectra in the C=N and C=O stretching regions reveal that both the nascent HCN and 2-oxopropyl (CH3C(O)CH2) radical products are vibrationally excited. The rate coefficient for the reaction of solvated CN with acetone is 40 times slower than for free CN, with a rate coefficient of (2.0 ± 0.9) × 109 M–1 s–1 obtained from the rise in the HCN product v1(C=N stretch) IR absorption band. Evidence is also presented for CN complexes with acetone that are more strongly bound than the CN–CDCl3 complexes because of CN interactions with the carbonyl group. The rates of reactions of these more strongly associated radicals are slower still. PMID:26192334

  8. Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp.

    PubMed

    Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa

    2015-08-01

    Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples.

  9. Vibrational Excitation of Both Products of the Reaction of CN Radicals with Acetone in Solution.

    PubMed

    Dunning, Greg T; Preston, Thomas J; Greaves, Stuart J; Greetham, Gregory M; Clark, Ian P; Orr-Ewing, Andrew J

    2015-12-17

    Transient electronic and vibrational absorption spectroscopy unravel the mechanisms and dynamics of bimolecular reactions of CN radicals with acetone in deuterated chloroform solutions. The CN radicals are produced by ultrafast ultraviolet photolysis of dissolved ICN. Two reactive forms of CN radicals are distinguished by their electronic absorption bands: "free" (uncomplexed) CN radicals, and "solvated" CN radicals that are complexed with solvent molecules. The lifetimes of the free CN radicals are limited to a few picoseconds following their photolytic production because of geminate recombination to ICN and INC, complexation with CDCl3 molecules, and reaction with acetone. The acetone reaction occurs with a rate coefficient of (8.0 ± 0.5) × 10(10) M(-1) s(-1) and transient vibrational spectra in the C═N and C═O stretching regions reveal that both the nascent HCN and 2-oxopropyl (CH3C(O)CH2) radical products are vibrationally excited. The rate coefficient for the reaction of solvated CN with acetone is 40 times slower than for free CN, with a rate coefficient of (2.0 ± 0.9) × 10(9) M(-1) s(-1) obtained from the rise in the HCN product v1(C═N stretch) IR absorption band. Evidence is also presented for CN complexes with acetone that are more strongly bound than the CN-CDCl3 complexes because of CN interactions with the carbonyl group. The rates of reactions of these more strongly associated radicals are slower still. PMID:26192334

  10. Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

    PubMed

    Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

    2016-09-30

    A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well. PMID:27629480

  11. Destruction of acetone using a small-scale arcjet plasma torch

    SciTech Connect

    Snyder, H.R.; Fleddermann, C.B.; Gahl, J.M.

    1996-12-31

    A small-scale thermal plasma torch has been constructed to determine the feasibility of its use to dispose of hazardous solvent wastes. The system has been studied using acetone as a test compound. The plasma jet is generated using argon and a commercial AC/DC welding supply. The system is operated using torch currents ranging from 50 to 200 A and solvent flow rates in the range 0--200 ml/h. Oxygen is added to alter the chemistry occurring in the reaction chamber. The destruction of acetone and the relative amounts of the reaction by-products are monitored using a residual gas analyzer. The pyrolysis products consist primarily of CO, CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and other C{sub x}H{sub y} radicals when no oxygen is added to the system. By adding oxygen to the system, thermal oxidation processes occur that increase the production of CO{sub 2} and significantly decrease the amount of acetone in the exhaust gases. This paper includes data on the destruction efficiency of acetone as a function of solvent flow rate, torch power, argon flow rate and oxygen injection rate. The results indicate that greater than 99% destruction efficiency of acetone can be achieved with addition of oxygen to the reaction mixture using an arcjet current of 75 A.

  12. Detection of Acetone Processing of Castor Bean Mash for Forensic Investigation of Ricin Preparation Methods

    SciTech Connect

    Kreuzer-Martin, Helen W.; Wahl, Jon H.; Metoyer, Candace N.; Colburn, Heather A.; Wahl, Karen L.

    2010-07-01

    The toxic protein ricin is of concern as a potential biological threat agent (BTA) Recently, several samples of ricin have been seized in connection with biocriminal activity. Analytical methods are needed that enable federal investigators to determine how the samples were prepared, to match seized samples to potential source materials, and to identify samples that may have been prepared by the same method using the same source materials. One commonly described crude ricin preparation method is acetone extraction of crushed castor beans. Here we describe the use of solid-phase microextraction and headspace analysis of crude ricin preparation samples to determine whether they were processed by acetone extraction. In all cases, acetone-extracted bean mash could be distinguished from un-extracted mash or mash extracted with other organic solvents. Statistical analysis showed that storage in closed containers for up to 109 days had no effect on acetone signal intensity. Signal intensity in acetone-extracted mash decreased during storage in open containers, but extracted mash could still be distinguished from un-extracted mash after 94 days.

  13. Dielectric barrier discharge micro-plasma emission spectrometry for the detection of acetone in exhaled breath.

    PubMed

    Yang, Ting; Gao, Dong-Xue; Yu, Yong-Liang; Chen, Ming-Li; Wang, Jian-Hua

    2016-01-01

    Acetone is a predominant volatile organic compound (VOC) in the exhaled breath and a promising biomarker for diabetes and ketoacidosis. A non-thermal micro-plasma generated in a planar dielectric barrier discharge (DBD) is used as a radiation source for the excitation of gaseous acetone followed by its quantification with optical emission spectrometry (OES). Gaseous acetone can be directly sampled, while liquid acetone is evaporated by heated tungsten coil and then introduced into the DBD micro-plasma by a helium carrier flow for performing optical emission and detection at a 519 nm emission line. In the present study, the exhaled breath is collected and transferred into aqueous medium for sampling. With a sampling volume of 7 μL in a micro-drop, a linear range of 40-1600 mg L(-1) is obtained along with a detection limit of 44 ng and a precision of 5.7% RSD. The present system is successfully applied to the determination of breath acetone for both diabetic patients and healthy volunteers. PMID:26695309

  14. On apparent quantized transition-state thresholds in the photofragmentation of acetaldehyde

    SciTech Connect

    King, Rollin A.; Allen, Wesley D.; Schaefer, Henry F. III

    2000-04-01

    Recent photofragmentation experiments have observed stepwise increases in the dissociation rate for CH{sub 3}CHO (T{sub 1}){yields}CH{sub 3} (X(tilde sign) {sup 2}A{sub 2}{sup ''})+HCO (X(tilde sign) {sup 2}A{sup '}) as a function of excitation energy. In accord with the Rice-Ramsperger-Kassel-Marcus (RRKM) form of transition-state theory, these steps were interpreted as corresponding to vibrational levels of the fragmentation transition state on the triplet surface. We have investigated this acetaldehyde dissociation using coupled cluster (CC) and density functional (DFT) methods with [C,O/H] atomic-orbital basis sets ranging in quality from [4s2p1d/2s1p] to [6s5p4d3f2g1h/5s4p3d2 f1g]. A high-level focal point analysis, along with harmonic force field computations, results in predictions of the dissociation energy, D{sub 0}=1583 cm{sup -1}, and the association barrier height, V{sub 0}{sup *}=3149 cm{sup -1}. With a basis set of triple-{zeta} plus double-polarization plus f(TZ2Pf ) quality, the DFT method UB3LYP and the CC method RCCSD predict barrier frequencies of 355i cm{sup -1} and 516i cm{sup -1}, respectively, while the empirical value inferred from RRKM models is only 60i cm{sup -1}. The RRKM-derived frequencies for the degrees of freedom orthogonal to the reaction path are more reasonable but still not in convincing agreement with electronic structure theory. Thus, while the experimental steps in the dissociation rate of acetaldehyde (as well as ketene) have yet to be satisfactorily explained, proven ab initio methods provide strong evidence that simple RRKM fits to the k(E) profile provide misleading vibrational frequencies of the transition state on the corresponding triplet potential energy surface. (c) 2000 American Institute of Physics.

  15. Synthesis and Characterisation of Porous Titania-Silica Composite Aerogel for NO(x) and Acetaldehyde Removal.

    PubMed

    Lee, Kwang Young; Park, Se Min; Kim, Jong Beom; El Saliby, Ibrahim; Shahid, Mohammad; Kim, Geon-Joong; Shon, Ho Kyong; Kim, Jong-Ho

    2016-05-01

    In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide. PMID:27483782

  16. Synthesis and Characterisation of Porous Titania-Silica Composite Aerogel for NO(x) and Acetaldehyde Removal.

    PubMed

    Lee, Kwang Young; Park, Se Min; Kim, Jong Beom; El Saliby, Ibrahim; Shahid, Mohammad; Kim, Geon-Joong; Shon, Ho Kyong; Kim, Jong-Ho

    2016-05-01

    In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide.

  17. Developmental and Reproductive Toxicology of Methanol

    EPA Science Inventory

    Methanol is a high production volume chemical used as a feedstock for chemical syntheses and as a solvent and fuel additive. Methanol is acutely toxic to humans, causing acidosis, blindness in death at high dosages, but its developmental and reproductive toxicity in humans is poo...

  18. Methanol Steam Reforming for Hydrogen Production

    SciTech Connect

    Palo, Daniel R.; Dagle, Robert A.; Holladay, Jamie D.

    2007-09-11

    Review article covering developments in methanol steam reforming in the context of PEM fuel cell power systems. Subjects covered include methanol background, use, and production, comparison to other fuels, power system considerations, militrary requirements, competing technologies, catalyst development, and reactor and system development and demonstration.

  19. Mechanisms of site-specific photochemistry following core-shell ionization of chemically inequivalent carbon atoms in acetaldehyde (ethanal)

    NASA Astrophysics Data System (ADS)

    Zagorodskikh, Sergey; Eland, John H. D.; Zhaunerchyk, Vitali; Mucke, Melanie; Squibb, Richard J.; Linusson, Per; Feifel, Raimund

    2016-09-01

    Site-specific fragmentation upon 1s photoionisation of acetaldehyde has been studied using synchrotron radiation and a multi-electron-ion coincidence technique based on a magnetic bottle. Experimental evidence is presented that bond rupture occurs with highest probability in the vicinity of the initial charge localisation and possible mechanisms are discussed. We find that a significant contribution to site-specific photochemistry is made by different fragmentation patterns of individual quantum states populated at identical ionisation energies.

  20. Flame front imaging in an internal-combustion engine simulator by laser-induced fluorescence of acetaldehyde.

    PubMed

    Arnold, A; Becker, H; Suntz, R; Monkhouse, P; Wolfrum, J; Maly, R; Pfister, W

    1990-08-01

    Acetaldehyde has been used as a fluorescent dopant for two-dimensional imaging of the flame front in an internalcombustion-engine simulator. The molecule was excited with a XeCl-laser-light sheet at 308 nm, and broadband fluorescence centered at 400 nm was detected. In this way, the flame front could be marked by mapping regions of unburned gas. Also, the intake process into the engine could be followed.

  1. Pharmacological recruitment of aldehyde dehydrogenase 3A1 (ALDH3A1) to assist ALDH2 in acetaldehyde and ethanol metabolism in vivo

    PubMed Central

    Chen, Che-Hong; Cruz, Leslie A.; Mochly-Rosen, Daria

    2015-01-01

    Correcting a genetic mutation that leads to a loss of function has been a challenge. One such mutation is in aldehyde dehydrogenase 2 (ALDH2), denoted ALDH2*2. This mutation is present in ∼0.6 billion East Asians and results in accumulation of toxic acetaldehyde after consumption of ethanol. To temporarily increase metabolism of acetaldehyde in vivo, we describe an approach in which a pharmacologic agent recruited another ALDH to metabolize acetaldehyde. We focused on ALDH3A1, which is enriched in the upper aerodigestive track, and identified Alda-89 as a small molecule that enables ALDH3A1 to metabolize acetaldehyde. When given together with the ALDH2-specific activator, Alda-1, Alda-89 reduced acetaldehyde-induced behavioral impairment by causing a rapid reduction in blood ethanol and acetaldehyde levels after acute ethanol intoxication in both wild-type and ALDH2-deficient, ALDH2*1/*2, heterozygotic knock-in mice. The use of a pharmacologic agent to recruit an enzyme to metabolize a substrate that it usually does not metabolize may represent a novel means to temporarily increase elimination of toxic agents in vivo. PMID:25713355

  2. The effect of SO2 on the production of ethanol, acetaldehyde, organic acids, and flavor volatiles during industrial cider fermentation.

    PubMed

    Herrero, Mónica; García, Luis A; Díaz, Mario

    2003-05-21

    SO(2) is widely used in cider fermentation but also in other alcoholic beverages such as wine. Although the authorized limit is 200 ppm total SO(2), the International Organizations recommend its total elimination or at least reduction due to health concerns. Addition of SO(2) to apple juice at levels frequently used in industrial cidermaking (100 mg/L) induced significantly higher acetaldehyde production by yeast than that obtained without SO(2). Although the practical implications of acetaldehyde evolution under cidermaking conditions has been overcome by research and few data are available, this compound reached levels in two 2000 L bioreactors that may have prevented the occurrence of simultaneous alcoholic and malolactic fermentation. It was observed that malolactic fermentation had a positive effect promoting reduction of acetaldehyde levels in cider fermented with juice, SO(2)-treated or not. The addition of SO(2) clearly delayed malolactic fermentation comparing to the control, affecting not the onset of the malolactic fermentation but the rate of malic acid degradation. This compound, however, had a stimulatory effect on alcoholic fermentation.

  3. Nucleoside adducts are formed by cooperative reaction of acetaldehyde and alcohols: possible mechanism for the role of ethanol in carcinogenesis.

    PubMed

    Fraenkel-Conrat, H; Singer, B

    1988-06-01

    The exocyclic amino groups of ribonucleosides and deoxyribonucleosides react rapidly at ambient temperature with acetaldehyde and alcohols to yield mixed acetals [--NH--CH(CH3)OR]. Nucleotides and nucleoside di- and triphosphates also react. Depending on the nucleoside used and on the relative amounts of aldehyde, alcohol, and water, preparative reactions reach equilibrium with yields up to 75% in a few hours. The structures have been confirmed by fast atom bombardment MS and proton NMR. Half-lives at 37 degrees C have been determined, and maximum stability is in the pH range of 7.5-9.5. In the absence of alcohol, acetaldehyde-nucleoside adducts could be isolated at 4 degrees C, but these were too unstable to characterize except for their UV spectra, also at 4 degrees C. Ethanol is often present in human blood and tissues, and acetaldehyde is its initial metabolic product, as well as being formed by many other metabolic processes. Both chemicals have separately been implicated in carcinogenic and other cytopathologic processes, but no cooperative mechanism has been proposed. The reactions reported here are of biological concern because they also occur in dilute aqueous solution. These findings supply a mechanism by which ethanol can be covalently bound to nucleic acids under physiological conditions.

  4. Taraxerone enhances alcohol oxidation via increases of alcohol dehyderogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities and gene expressions.

    PubMed

    Sung, Chang-Keun; Kim, Seung-Mi; Oh, Chang-Jin; Yang, Sun-A; Han, Byung-Hee; Mo, Eun-Kyoung

    2012-07-01

    The present study, taraxerone (d-friedoolean-14-en-3-one) was isolated from Sedum sarmentosum with purity 96.383%, and its enhancing effects on alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities were determined: EC(50) values were 512.42 ± 3.12 and 500.16 ± 3.23 μM for ADH and ALDH, respectively. In order to obtain more information on taraxerone related with the alcohol metabolism, 40% ethanol (5 mL/kg body weight) with 0.5-1mM of taraxerone were administered to mice. The plasma alcohol and acetaldehyde concentrations of taraxerone-treated groups were significantly lowered than those of the control group (p<0.01): approximately 20-67% and 7-57% lowered for plasma alcohol and acetaldehyde, respectively. Compare to the control group, the ADH and ALDH expressions in the liver tissues were abruptly increased in the taraxerone-treated groups after ethanol exposure. In addition, taraxerone prevented catalase, superoxide dismutase, and reduced glutathione concentrations from the decrease induced by ethanol administration with the concentration dependent manner.

  5. Adsorption, Coadsorption and Reaction of Acetaldehyde and NO₂ on Na-Y,FAU: an in situ FTIR Investigation

    SciTech Connect

    Szanyi, Janos; Kwak, Ja Hun; Moline, Ryan A.; Peden, Charles HF

    2004-11-04

    The adsorption of acetaldehyde and its co-adsorption and reaction with NO₂ were investigated on a Na-Y, FAU zeolite using in situ FTIR spectroscopy. Acetaldehyde adsorbs strongly over Na-Y and desorbs molecularly at around 400K with very limited extent of condensation or polymerization. Reaction between CH₃CHO and NO₂ takes place in co-adsorption experiments even at 300K. In the initial step, acetaldehyde is oxidized to acetic acid accompanied by the formation of NO, which can be observed as N2O₃ formed via a further reaction between NO and NO₂. The key intermediates in the overall NOx reduction in this process are nitro- and nitrosomethane, which form in the next step. Their decomposition and further reaction with adsorbed NOx species lead to the formation of HCN, HNCO, N₂O, CO₂ and organic nitrile species identified by their characteristic IR vibrational signatures. At 473K, the reaction between adsorbed CH₃CHO and NO₂ is very fast. The results seem to suggest a mechanism in which N-N bond formation takes place among ionic nitrogen containing species (NO⁺ and CN⁻ or NCO⁻). No evidence has been found to suggest the participation of NHx⁺NOy⁻ type species in the N⁻N bond formation under the experimental conditions of this study.

  6. Ethanol formation in adh0 mutants reveals the existence of a novel acetaldehyde-reducing activity in Saccharomyces cerevisiae.

    PubMed Central

    Drewke, C; Thielen, J; Ciriacy, M

    1990-01-01

    A strain of Saccharomyces cerevisiae has been constructed which is deficient in the four alcohol dehydrogenase (ADH) isozymes known at present. This strain (adh0), being irreversibly mutated in the genes ADH1, ADH3, and ADH4 and carrying a point mutation in the gene ADH2 coding for the glucose-repressible isozyme ADHII, still produces up to one third of the theoretical maximum yield of ethanol in a homofermentative conversion of glucose to ethanol. Analysis of the glucose metabolism of adh0 cells shows that the lack of all known ADH isozymes results in the formation of glycerol as a major fermentation product, accompanied by a significant production of acetaldehyde and acetate. Treatment of glucose-growing adh0 cells with the respiratory-chain inhibitor antimycin A leads to an immediate cessation of ethanol production, demonstrating that ethanol production in adh0 cells is dependent on mitochondrial electron transport. Reduction of acetaldehyde to ethanol in isolated mitochondria could also be demonstrated. This reduction is apparently linked to the oxidation of acetaldehyde to acetate. Preliminary data suggest that this novel type of ethanol formation in S. cerevisiae is associated with the inner mitochondrial membrane. Images PMID:2193925

  7. Evaluating acetaldehyde synthesis from L-/sup 14/C(U)) threonine by Streptococcus thermophilus and Lactobacillus bulgaricus

    SciTech Connect

    Wilkins, D.W.; Schmidt, R.H.; Shireman, R.B.; Smith, K.L.; Jezeski, J.J.

    1986-05-01

    To evaluate the synthesis of acetaldehyde from threonine during growth of yogurt cultures, Streptococcus thermophilus MS1 and Lactobacillus bulgaricus MR1 were grown in defined medium in which 10% of the total threonine was composed of L-(carbon-14(U))threonine. Acetaldehyde production was monitored by formation of 2,4-dinitrophenylhydrazone followed by separation and analysis using high performance liquid chromatography. After growth for 8 h at 42/sup 0/C, approximately 2.0% of the total acetaldehyde (780.4 nmol) produced was from L-(carbon-14)threonine. Threonine aldolase activity was determined in cell-free extracts from S. thermophilus and L. bulgaricus grown in Elliker broth. Increasing incubation temperature from 30 to 42/sup 0/C decreased threonine aldolase activity in cells of the streptococcus harvested after 8 h of incubation. Effect of incubation temperature was more dramatic in cells harvested after 18 h where the activity of cells grown at 48/sup 0/C was 89% lower than that of cells grown at 30/sup 0/C. Cell extracts from S. thermophilus MS1 possessed higher threonine aldolase activity than did those from L. bulgaricus MR1. Increased assay temperature from 30 to 42/sup 0/C increased threonine aldolase activity in S. thermophilus MS1.

  8. Measurement of Fuel Concentration Profile at Leading Edge of Lifted Flame with Acetone Laser-Induced Fluorescence

    NASA Astrophysics Data System (ADS)

    Hirota, Mitsutomo; Sekine, Kazushi; Hashimoto, Kouta; Saiki, Atsushi; Takahashi, Hidemi; Masuya, Goro

    This is a study of the leading-edge characteristics of a methane-air triple flame. Few experiment results are available for physical examination of such characteristics, so further experimental investigations are strongly needed to understand the stability mechanism in a mixture with a steep concentration gradient. To this end, we measured concentration profiles at the leading edge of a flame using acetone laser-induced fluorescence (acetone LIF). The results demonstrated that the lifted height of the flame changed when acetone was added to the mixture and correlated well with increased C2 radical behind the flame edge. However, the OH radical luminous intensity, measured with a spectroscope, did not change with addition of acetone. Moreover, the burning velocity obtained by the Bunsen-burner method remained constant when acetone was added to the mixture. Therefore, acetone had little influence on burning intensity. Acetone LIF can thus be employed to measure the local concentration gradient at the leading edge of a flame. The acetone LIF signals could be corrected to consider the thermal effect by using silicone oil vanishing-plane data. From the corrected acetone LIF data, the width between the lean and rich flammability limits (flammability limit width) in the flow upstream of the flame with a steep concentration gradient was clearly observed and could be quantitatively compared with the recent numerical results.

  9. Using acetone as solvent to study removal of anthracene in soil inhibits microbial activity and alters nitrogen dynamics.

    PubMed

    Núñez, Edgar Vázquez; Rodríguez, Viviana; Gaytán, Alejandro García; Luna-Guido, Marco; Betancur-Galvis, Liliana A; Marsch, Rodolfo; Dendooven, Luc

    2009-08-01

    Acetone is often used as a carrier to contaminate soil with polycyclic aromatic hydrocarbons (PAHs) and then to study the factors that control their removal. Acetone is an organic solvent that might affect soil processes. An alkaline saline (Texcoco soil) and an agricultural soil (Acolman soil) were amended with or without acetone, nitrogen + phosphorus (NP), and contaminated with anthracene at 520 mg/kg soil while emissions of CO2 and N2O and concentrations of NH4+, NO2(-) and NO3(-) were monitored. The CO2 emission rate decreased greater than 10 times in the soils amended with acetone. Emission of N2O decreased 70 times in the Acolman soil amended with acetone and NP and 5 times in the Texcoco soil. The concentration of NH4+ decreased in the unamended Acolman and Texcoco soil but increased when acetone was added in the first and remained constant in the latter. Acetone inhibited the increase in the amount of NO3(-) in the Acolman soil but not in the Texcoco soil. It was found that microbial activity as evidenced by the emission of CO2, nitrification, and production of N2O were inhibited by acetone. The amount of acetone used as solvent should thus be kept to a minimum, but it can be assumed that its effect on soil processes will be temporary, as microorganisms are known to repopulate soil quickly.

  10. Increased blood concentration of isopropanol in ketotic dairy cows and isopropanol production from acetone in the rumen.

    PubMed

    Sato, Hiroshi

    2009-08-01

    To evaluate acetone and isopropanol metabolism in bovine ketosis, the blood concentrations of isopropanol, acetone, plasma 3-hydroxybutyrate (3-HB) and other metabolites were analyzed in 12 healthy controls and 15 ketotic dairy cows including fatty liver and inferior prognosis after laparotomy for displaced abomasum. In ruminal fluid taken from 6 ketotic cows, ruminal isopropanol and acetone were also analyzed. Ketotic cows showed higher concentrations of isopropanol, acetone, 3-HB and nonesterified fatty acid, and higher activities of aspartate transaminase and gamma-glutamyl transferase than control cows. Blood samples had higher concentration of isopropanol accompanied by increased acetone. In the ketotic cows, acetone was detected not only in blood but also in ruminal fluid, while higher ruminal isopropanol did not necessarily accompany its elevation in the blood. Using 2 steers with rumen cannula, all ruminal content was emptied and then substituted with artificial saliva to evaluate the importance of ruminal microbes in isopropanol production. Under each condition of intact and emptied rumen, acetone was infused into the rumen and blood isopropanol was analyzed. The elevation in the blood isopropanol concentration after acetone infusion was markedly inhibited by the emptying. Here, increased blood concentrations of isopropanol and acetone were observed in ketotic cows, and the importance of ruminal microbes in isopropanol production was confirmed.

  11. High-sensitivity detection of triacetone triperoxide (TATP) and its precursor acetone

    NASA Astrophysics Data System (ADS)

    Dunayevskiy, Ilya; Tsekoun, Alexei; Prasanna, Manu; Go, Rowel; Patel, C. Kumar N.

    2007-09-01

    Triacetone triperoxide (C9H18O6, molecular mass of 222.24 g/mol) (TATP) is a powerful explosive that is easy to synthesize using commonly available household chemicals, acetone, and hydrogen peroxide 1 2. Because of the simplicity of its synthesis, TATP is often the explosive of choice for terrorists, including suicide bombers. For providing safety to the population, early detection of TATP and isolation of such individuals are essential. We report unambiguous, high-sensitivity detection of TATP and its precursor, acetone, using room-temperature quantum cascade laser photoacoustic spectroscopy (QCL-PAS). The available sensitivity is such that TATP, carried on a person (at a nominal body temperature of 37 °C), should be detectable at some distance. The combination of demonstrated detection of TATP and acetone should be ideal for screening at airports and other public places for providing increased public safety.

  12. Detection of Interstellar Acetone toward the Orion-KL Hot Core

    NASA Astrophysics Data System (ADS)

    Friedel, D. N.; Snyder, L. E.; Remijan, Anthony J.; Turner, B. E.

    2005-10-01

    We present the first detection of interstellar acetone [(CH3)2CO] toward the high-mass star-forming region Orion-KL and the first detection of vibrationally excited (CH3)2CO in the interstellar medium (ISM). Using the BIMA array, 28 emission features that can be assigned to 54 acetone transitions were detected. Furthermore, 37 of these transitions have not been previously observed in the ISM. The observations also show that the acetone emission is concentrated toward the hot core region of Orion-KL, contrary to the distribution of other large oxygen-bearing molecules. From our rotational temperature diagram, we find a beam-averaged (CH3)2CO column density of [2.0(0.3)-8.0(1.2)]×1016 cm-2 and a rotational temperature of 176(48)-194(66) K.

  13. Mid-Infrared vibrational spectra of discrete acetone-ligated cerium hydroxide cations

    SciTech Connect

    G. S. Groenewold; A. K. Gianotto; K. C. Cossel; M. J. Van Stipdonk; J. Oomens; N. Polfer; W. A. De JOng; M. E. McIllwain

    2007-02-01

    Cerium (III) hydroxy reactive sites are responsible for several important heterogeneous catalysis processes, and understanding the reaction chemistry of substrate molecules like CO, H2O, and CH3OH as they occur in heterogeneous media is a challenging task. We report here the first infrared spectra of model gas-phase cerium complexes and use the results as a benchmark to assist evaluation of the accuracy of ab initio calculations. Complexes containing [CeOH]2+ ligated by three- and four-acetone molecules were generated by electrospray ionization and characterized using wavelength-selective infrared multiple photon dissociation (IRMPD). The C=O stretching frequency for the [CeOH(acetone)4]2+ species appeared at 1650 cm-1 and was red-shifted by 90 cm-1 compared to unligated acetone. The magnitude of this shift for the carbonyl frequency was even greater for the [CeOH(acetone)3]2+ complex: the IRMPD peak consisted of two dissociation channels, an initial elimination of acetone at 1635 cm-1, and elimination of acetone accompanied by a serial charge separation producing [CeO(acetone)]+ at 1599 cm-1, with the overall frequency centered at 1616 cm-1. The increasing red shift observed as the number of acetone ligands decreases from four to three is consistent with transfer of more electron density per ligand in the less coordinated complexes. The lower frequency measured for the elimination/charge separation process is likely due to anharmonicity resulting from population of higher vibrational states. The C-C stretching frequency in the complexes is also influenced by coordination to the metal: it is blue-shifted compared to bare acetone, indicating a slight strengthening of the C-C bond in the complex, with the intensity of the absorption decreasing with decreasing ligation. Density functional theory (DFT) calculations using three different functionals (LDA, B3LYP, and PBE0) are used to predict the infrared spectra of the complexes. Calculated frequencies for the carbonyl

  14. Mid-Infrared Vibrational Spectra of Discrete Acetone-Ligated Cerium Hydroxide Cations

    SciTech Connect

    Groenewold, G. S.; Gianotto, Anita K.; Cossel, Kevin C.; Van Stipdonk, Michael J.; Oomens, Jos; Polfer, Nick; Moore, D.T.; De Jong, Wibe A.; McIIwain, Michael E.

    2007-02-15

    Cerium (III) hydroxy reactive sites are responsible for several important heterogeneous catalysis processes, and understanding the reaction chemistry of substrate molecules like CO, H2O, and CH3OH as they occur in heterogeneous media is a challenging task. We report here the first infrared spectra of model gas-phase cerium complexes and use the results as a benchmark to assist evaluation of the accuracy of ab initio calculations. Complexes containing [CeOH]2+ ligated by three- and four-acetone molecules were generated by electrospray ionization and characterized using wavelength-selective infrared multiple photon dissociation (IRMPD). The C=O stretching frequency for the [CeOH(acetone)4]2+ species appeared at 1650 cm-1 and was red-shifted by 90 cm-1 compared to unligated acetone. The magnitude of this shift for the carbonyl frequency was even greater for the [CeOH(acetone)3]2+ complex: the IRMPD peak consisted of two dissociation channels, an initial elimination of acetone at 1635 cm-1, and elimination of acetone accompanied by a serial charge separation producing [CeO(acetone)]+ at 1599 cm-1, with the overall frequency centered at 1616 cm-1. The increasing red shift observed as the number of acetone ligands decreases from four to three is consistent with transfer of more electron density per ligand in the less coordinated complexes. The lower frequency measured for the elimination/charge separation process is likely due to anharmonicity resulting from population of higher vibrational states. The C-C stretching frequency in the complexes is also influenced by coordination to the metal: it is blue-shifted compared to bare acetone, indicating a slight strengthening of the C-C bond in the complex, with the intensity of the absorption decreasing with decreasing ligation. Density functional theory (DFT) calculations using three different functionals (LDA, B3LYP, and PBE0) are used to predict the infrared spectra of the complexes. Calculated frequencies for the carbonyl

  15. Thiamine pyrophosphate stimulates acetone activation by Desulfococcus biacutus as monitored by a fluorogenic ATP analogue.

    PubMed

    Gutiérrez Acosta, Olga B; Hardt, Norman; Hacker, Stephan M; Strittmatter, Tobias; Schink, Bernhard; Marx, Andreas

    2014-06-20

    Acetone can be degraded by aerobic and anaerobic microorganisms. Studies with the strictly anaerobic sulfate-reducing bacterium Desulfococcus biacutus indicate that acetone degradation by these bacteria starts with an ATP-dependent carbonylation reaction leading to acetoacetaldehyde as the first reaction product. The reaction represents the second example of a carbonylation reaction in the biochemistry of strictly anaerobic bacteria, but the exact mechanism and dependence on cofactors are still unclear. Here, we use a novel fluorogenic ATP analogue to investigate its mechanism. We find that thiamine pyrophosphate is a cofactor of this ATP-dependent reaction. The products of ATP cleavage are AMP and pyrophosphate, providing first insights into the reaction mechanism by indicating that the reaction proceeds without intermediate formation of acetone enol phosphate.

  16. Mobility and molecular ions of dimethyl methyl phosphonate, methyl salicylate and acetone

    NASA Astrophysics Data System (ADS)

    Nowak, D. M.

    1983-06-01

    The mobilities of positive and negative reactant ions are reported for (H2O)nH(+); (H2O)2O2 and (H2O)2CO3(-) ion clusters. The formation of positive DMMP monomer and dimer is reported, and equilbria molecular reactions are reported. Acetone is reported as forming a dimer at 81 ppb with a reduced mobility (K sub o) of 1.82, Methyl salicylate is shown to form a protonated and hydrated positive monomer. Mixtures of DMMP and methyl salicylate with acetone showed a substantial change in DMMP ion clustering and little or no change in the methyl salicylate mobility spectra. Negative ions were not observed for DMMP, methyl salicylate, acetone and the mixtures under the conditions reported.

  17. Acetone-Linked Peptides: A Convergent Approach for Peptide Macrocyclization and Labeling.

    PubMed

    Assem, Naila; Ferreira, David J; Wolan, Dennis W; Dawson, Philip E

    2015-07-20

    Macrocyclization is a broadly applied approach for overcoming the intrinsically disordered nature of linear peptides. Herein, it is shown that dichloroacetone (DCA) enhances helical secondary structures when introduced between peptide nucleophiles, such as thiols, to yield an acetone-linked bridge (ACE). Aside from stabilizing helical structures, the ketone moiety embedded in the linker can be modified with diverse molecular tags by oxime ligation. Insights into the structure of the tether were obtained through co-crystallization of a constrained S-peptide in complex with RNAse S. The scope of the acetone-linked peptides was further explored through the generation of N-terminus to side chain macrocycles and a new approach for generating fused macrocycles (bicycles). Together, these studies suggest that acetone linking is generally applicable to peptide macrocycles with a specific utility in the synthesis of stabilized helices that incorporate functional tags.

  18. Demonstration of a mid-infrared cavity enhanced absorption spectrometer for breath acetone detection.

    PubMed

    Ciaffoni, Luca; Hancock, Gus; Harrison, Jeremy J; van Helden, Jean-Pierre H; Langley, Cathryn E; Peverall, Robert; Ritchie, Grant A D; Wood, Simon

    2013-01-15

    A high-resolution absorption spectrum of gaseous acetone near 8.2 μm has been taken using both Fourier transform and quantum cascade laser (QCL)-based infrared spectrometers. Absolute absorption cross sections within the 1215-1222 cm(-1) range have been determined, and the spectral window around 1216.5 cm(-1) (σ = 3.4 × 10(-19) cm(2) molecule(-1)) has been chosen for monitoring trace acetone in exhaled breath. Acetone at sub parts-per-million (ppm) levels has been measured in a breath sample with a precision of 0.17 ppm (1σ) by utilizing a cavity enhanced absorption spectrometer constructed from the QCL source and a linear, low-volume, optical cavity. The use of a water vapor trap ensured the accuracy of the results, which have been corroborated by mass spectrometric measurements.

  19. High-sensitivity detection of triacetone triperoxide (TATP) and its precursor acetone.

    PubMed

    Dunayevskiy, Ilya; Tsekoun, Alexei; Prasanna, Manu; Go, Rowel; Patel, C Kumar N

    2007-09-01

    Triacetone triperoxide (C(9)H(18)O(6), molecular mass of 222.24 g/mol) (TATP) is a powerful explosive that is easy to synthesize using commonly available household chemicals, acetone, and hydrogen peroxide 1 2. Because of the simplicity of its synthesis, TATP is often the explosive of choice for terrorists, including suicide bombers. For providing safety to the population, early detection of TATP and isolation of such individuals are essential. We report unambiguous, high-sensitivity detection of TATP and its precursor, acetone, using room-temperature quantum cascade laser photoacoustic spectroscopy (QCL-PAS). The available sensitivity is such that TATP, carried on a person (at a nominal body temperature of 37 degrees C), should be detectable at some distance. The combination of demonstrated detection of TATP and acetone should be ideal for screening at airports and other public places for providing increased public safety.

  20. Decomposition of acetone by hydrogen peroxide/ozone process in a rotating packed contactor.

    PubMed

    Ku, Young; Huang, Yun-Jen; Chen, Hua-Wei; Hou, Wei-Ming

    2011-07-01

    The direct use of ozone (O3) in water and wastewater treatment processes is found to be inefficient, incomplete, and limited by the ozone transfer between the gas-liquid interface because of its low solubility and instability in aqueous solutions. Therefore, rotating packed contactors were introduced to improve the transfer of ozone from the gaseous phase to the solution phase, and the effect of several reaction parameters were investigated on the temporal variations of acetone concentration in aqueous solution. The decomposition rate constant of acetone was enhanced by increasing the rotor speed from 450 to 1800 rpm. Increasing the hydrogen peroxide (H2O2)/O3 molar ratios accelerated the decomposition rate until a certain optimum H2O2/O3 molar ratio was reached; further addition of H2O2 inhibited the decomposition of acetone, possibly because excessive amounts of H2O2 added might serve as a scavenger to deplete hydroxyl free radicals.

  1. Acetone Sensing Properties of a Gas Sensor Composed of Carbon Nanotubes Doped With Iron Oxide Nanopowder

    PubMed Central

    Tan, Qiulin; Fang, Jiahua; Liu, Wenyi; Xiong, Jijun; Zhang, Wendong

    2015-01-01

    Iron oxide (Fe2O3) nanopowder was prepared by a precipitation method and then mixed with different proportions of carbon nanotubes. The composite materials were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. A fabricated heater-type gas sensor was compared with a pure Fe2O3 gas sensor under the influence of acetone. The effects of the amount of doping, the sintering temperature, and the operating temperature on the response of the sensor and the response recovery time were analyzed. Experiments show that doping of carbon nanotubes with iron oxide effectively improves the response of the resulting gas sensors to acetone gas. It also reduces the operating temperature and shortens the response recovery time of the sensor. The response of the sensor in an acetone gas concentration of 80 ppm was enhanced, with good repeatability. PMID:26569253

  2. Ethanol-derived acetaldehyde: pleasure and pain of alcohol mechanism of action

    PubMed Central

    Muggironi, Giulia; Fois, Giulia R.; Diana, Marco

    2013-01-01

    Acetaldehyde (ACD), the first metabolite of ethanol (EtOH), has been implicated in several actions of alcohol, including its reinforcing effects. Previously considered an aversive compound, ACD was useful in alcoholic’s pharmacological treatment aimed at discouraging alcohol drinking. However, it has recently been shown that EtOH-derived ACD is necessary for EtOH-induced place preference and self-administration, thereby suggesting a possible involvement of ACD in EtOH motivational properties. In addition, EtOH-stimulating properties on DA neurons are prevented by pharmacological blockade of local catalase H2O2 system, the main metabolic step for biotransformation of EtOH into ACD within the central nervous system. It was further shown that pretreatment with thiol compounds, like L-Cysteine or D-Penicillamine, reduced EtOH and ACD-induced motivational effects, in fact preventing self-administration of both EtOH and ACD, thus suggesting a possible role for ACD as a biomarker useful in evaluating potential innovative treatments of alcohol abuse. These findings suggest a key role of ACD in the EtOH reinforcing effects. In the present paper we review the role of EtOH-derived ACD in the reinforcing effects of EtOH and the possibility that ACD may serve as a therapeutically targetable biomarker in the search for novel treatments in alcohol abuse and alcoholism. PMID:23882197

  3. Recombinant human diamine oxidase activity is not inhibited by ethanol, acetaldehyde, disulfiram, diethyldithiocarbamate or cyanamide.

    PubMed

    Bartko, Johann; Gludovacz, Elisabeth; Petroczi, Karin; Borth, Nicole; Jilma, Bernd; Boehm, Thomas

    2016-08-01

    Human diamine oxidase (hDAO, EC 1.4.3.22) is the key enzyme in the degradation of extracellular histamine. Consumption of alcohol is a known trigger of mast cell degranulation in patients with mast cell activation syndrome. Ethanol may also interfere with enzymatic histamine degradation, but reports on the effects on DAO activity are controversial. There are also conflicting reports whether disulfiram, an FDA-approved agent in the treatment of alcohol dependence, inhibits DAO. We therefore investigated the inhibitory potential of ethanol and disulfiram and their metabolites on recombinant human DAO (rhDAO) in three different assay systems. Relevant concentrations of ethanol, acetaldehyde, and acetate did not inhibit rhDAO activity in an in vitro assay system using horseradish peroxidase (HRP) -mediated luminol oxidation. The aldehyde dehydrogenase (ALDH; EC 1.2.1.3) inhibitors cyanamide and its dimer dicyanamide also had no effect on DAO activity. In one assay system, the irreversible ALDH inhibitor disulfiram and its main metabolite diethyldithiocarbamate seemed to inhibit DAO activity. However, the decreased product formation was not due to a direct block of DAO activity but resulted from inhibition of peroxidase employed in the coupled system. Our in vitro data do not support a direct blocking effect of ethanol, disulfiram, and their metabolites on DAO activity in vivo. PMID:27401969

  4. Insights into photodissociation dynamics of acetaldehyde from ab initio calculations and molecular dynamics simulations

    SciTech Connect

    Chen Shilu; Fang Weihai

    2009-08-07

    In the present paper we report a theoretical study on mechanistic photodissociation of acetaldehyde (CH{sub 3}CHO). Stationary structures for H{sub 2} and CO eliminations in the ground state (S{sub 0}) have been optimized with density functional theory method, which is followed by the intrinsic reaction coordinate and ab initio molecular dynamics calculations to confirm the elimination mechanism. Equilibrium geometries, transition states, and intersection structures for the C-C and C-H dissociations in excited states were determined by the complete-active-space self-consistent field (CASSCF) method. Based on the CASSCF optimized structures, the potential energy profiles for the dissociations were refined by performing the single-point calculations using the multireference configuration interaction method. Upon the low-energy irradiation of CH{sub 3}CHO (265 nm<{lambda}<318 nm), the T{sub 1} C-C bond fission following intersystem crossing from the S{sub 1} state is the predominant channel and the minor channel, the ground-state elimination to CH{sub 4}+CO after internal conversion (IC) from S{sub 1} to S{sub 0}, could not be excluded. With the photon energy increasing, another pathway of IC, achieved via an S{sub 1}/S{sub 0} intersection point resulting from the S{sub 1} C-C bond fission, becomes accessible and increases the yield of CH{sub 4}+CO.

  5. Photodissociation of acetaldehyde and the absolute photoionization cross section of HCO.

    SciTech Connect

    Shubert, V. A.; Pratt, S. T.

    2010-01-01

    Photodissociation of acetaldehyde (CH{sub 3}CHO) at 266 nm produced CH{sub 3} and HCO radicals, and single-photon vacuum ultraviolet ionization was used to record velocity map ion images of both CH{sub 3}{sup +} and HCO{sup +}. Comparison of the translational energy distributions from both species indicates that secondary fragmentation of HCO is negligible for 266 nm photodissociation. Thus, the relative photoion signals for CH{sub 3}{sup +} and HCO{sup +} in the mass spectrometer, combined with the recently measured absolute photoionization cross section of CH{sub 3}, allowed the determination of the absolute photoionization cross section of HCO ({sigma}(HCO) = 4.8 {+-} {sub 1.5}{sup 2.0}, 5.9 {+-} {sub 1.6}{sup 2.2}, and 3.7 {+-} {sub 1.2}{sup 1.6} Mb at 10.257, 10.304, and 10.379 eV, respectively). The observed values are quite small but consistent with the similarly small value at threshold for the isoelectronic species NO. This behavior is discussed in terms of the character of the HOMO in both molecules.

  6. Acetaldehyde metabolism by brain mitochondria from UChA and UChB rats.

    PubMed

    Quintanilla, M E; Tampier, L

    1995-01-01

    The acetaldehyde (AcH) oxidizing capacity of total brain homogenates from the genetically high-ethanol consumer (UChB) appeared to be greater than that of the low-ethanol consumer (UChA) rats. To gain further information about this strain difference, the activity of aldehyde dehydrogenase (AIDH) in different subcellular fractions of whole brain homogenates from naive UChA and UChB rat strains of both sexes has been studied by measuring the rate of AcH disappearance and by following the reduction of NAD to NADH. The results demonstrated that the higher capacity of brain homogenates from UChB rats to oxidize AcH when compared to UChA ones was because the UChB mitochondrial low Km AIDH exhibits a much greater affinity for NAD than that of the UChA rats, as evidenced by four-to fivefold differences in the Km values for NAD. But the dehydrogenases from both strains exhibited a similar maximum rate at saturating NAD concentrations. Because intact brain mitochondria isolated from UChB rats oxidized AcH at a higher rate than did mitochondria from UChA rats only in state 4, but not in state 3, this strain difference in AIDH activity might be restricted in vivo to NAD disposition.

  7. Hypersensitivities for acetaldehyde and other agents among cancer cells null for clinically relevant Fanconi anemia genes.

    PubMed

    Ghosh, Soma; Sur, Surojit; Yerram, Sashidhar R; Rago, Carlo; Bhunia, Anil K; Hossain, M Zulfiquer; Paun, Bogdan C; Ren, Yunzhao R; Iacobuzio-Donahue, Christine A; Azad, Nilofer A; Kern, Scott E

    2014-01-01

    Large-magnitude numerical distinctions (>10-fold) among drug responses of genetically contrasting cancers were crucial for guiding the development of some targeted therapies. Similar strategies brought epidemiological clues and prevention goals for genetic diseases. Such numerical guides, however, were incomplete or low magnitude for Fanconi anemia pathway (FANC) gene mutations relevant to cancer in FANC-mutation carriers (heterozygotes). We generated a four-gene FANC-null cancer panel, including the engineering of new PALB2/FANCN-null cancer cells by homologous recombination. A characteristic matching of FANCC-null, FANCG-null, BRCA2/FANCD1-null, and PALB2/FANCN-null phenotypes was confirmed by uniform tumor regression on single-dose cross-linker therapy in mice and by shared chemical hypersensitivities to various inter-strand cross-linking agents and γ-radiation in vitro. Some compounds, however, had contrasting magnitudes of sensitivity; a strikingly high (19- to 22-fold) hypersensitivity was seen among PALB2-null and BRCA2-null cells for the ethanol metabolite, acetaldehyde, associated with widespread chromosomal breakage at a concentration not producing breaks in parental cells. Because FANC-defective cancer cells can share or differ in their chemical sensitivities, patterns of selective hypersensitivity hold implications for the evolutionary understanding of this pathway. Clinical decisions for cancer-relevant prevention and management of FANC-mutation carriers could be modified by expanded studies of high-magnitude sensitivities.

  8. Polymerization of Formaldehyde and Acetaldehyde on Ordered (WO3)3 Films on Pt(111)

    SciTech Connect

    Li, Zhenjun; Zhang, Zhenrong; Kay, Bruce D.; Dohnalek, Zdenek

    2011-05-19

    Polymerization of formaldehyde, H2CO, and acetaldehyde, CH3CHO, was studied under ultrahigh vacuum conditions on a model catalyst consisting of an ultra-thin WO3 film supported on Pt(111). The onset of polymerization is observed at very low temperatures of 70 and 80 K for H2CO and CH3CHO, respectively, as documented by the evolution of the IRAS spectra. The amount of polymer increases with increasing coverage and saturates at 5 and 8 monolayers (ML) for the H2CO and CH3CHO multilayer films that are thicker than 10 and 15 ML, respectively. Upon heating, the polymers decompose around 250 and 190 K for H2CO and CH3CHO, respectively, as evidenced mass spectrometrically by the desorption of their monomers and oligomers into the gas phase. The heats of H2CO and CH3CHO sublimation and polymerization determined based on our experiments are in good agreement with previously published values.

  9. Thz Spectroscopy of Acetaldehyde and Search of 13C Species in Orion

    NASA Astrophysics Data System (ADS)

    Margulès, L.; Motiyenko, R. A.; Ilyushin, V. V.; Tercero, B.; Cernicharo, J.; Guillemin, J.-C.

    2012-06-01

    Acetaldehyde (CH_3CHO) is one of the high priority complex organic molecules for the astrophysical community. There is a lack of data concerning the 13C species since the measurements are limited to 40 GHz up to date. This molecule displays a large amplitude motion: the hindered rotation of the methyl group with respect to the rest of the molecule. The analysis is performed with RAM36 code which used the Rho Axis Method. Last year we presented the analysis of the millimeterwave spectra of the 13CH_3CHO species. We extended the analysis to the THz range of the vibrational ground state for both species. We are also analyzing the first torsional state (≈140 cm-1) for two reasons: first, this permits to remove correlation between parameters. Second, this state contribute to the partition function even at ISM temperature (100--150 K) since there is an influence on the column density determined in case of detection. The searches of these isotopomers are in progress in ORION. This work was supported by the CNES and the Action sur Projets de l'INSU, PCMI. This work was also done under the ANR-08-BLAN-0054. Kilb, R.W.; Lin, C.C.; and Wilson, E.B. J. Chem. Phys. 26, (1957) 1695 Ilyushin, V.V. et al J. Mol. Spectrosc. 259, (2010) 26 Margules, L. et al. FA07, 66th International Symposium on Molecular Spectroscopy (2011)

  10. Acetaldehyde reinforcement and motor reactivity in newborns with or without a prenatal history of alcohol exposure.

    PubMed

    March, Samanta M; Culleré, Marcela E; Abate, Paula; Hernández, José I; Spear, Norman E; Molina, Juan C

    2013-01-01

    Animal models have shown that early ontogeny seems to be a period of enhanced affinity to ethanol. Interestingly, the catalase system that transforms ethanol (EtOH) into acetaldehyde (ACD) in the brain, is more active in the perinatal rat compared to adults. ACD has been found to share EtOH's behavioral effects. The general purpose of the present study was to assess ACD motivational and motor effects in newborn rats as a function of prenatal exposure to EtOH. Experiment 1 evaluated if ACD (0.35 μmol) or EtOH (0.02 μmol) supported appetitive conditioning in newborn pups prenatally exposed to EtOH. Experiment 2 tested if prenatal alcohol exposure modulated neonatal susceptibility to ACD's motor effects (ACD dose: 0, 0.35 and 0.52 μmol). Experiment 1 showed that EtOH and ACD supported appetitive conditioning independently of prenatal treatments. In Experiment 2, latency to display motor activity was altered only in neonates prenatally treated with water and challenged with the highest ACD dose. Prenatal EtOH experience results in tolerance to ACD's motor activity effects. These results show early susceptibility to ACD's appetitive effects and attenuation of motor effects as a function of prenatal history with EtOH, within a stage in development where brain ACD production seems higher than later in life.

  11. Acetaldehyde reinforcement and motor reactivity in newborns with or without a prenatal history of alcohol exposure

    PubMed Central

    March, Samanta M.; Culleré, Marcela E.; Abate, Paula; Hernández, José I.; Spear, Norman E.; Molina, Juan C.

    2013-01-01

    Animal models have shown that early ontogeny seems to be a period of enhanced affinity to ethanol. Interestingly, the catalase system that transforms ethanol (EtOH) into acetaldehyde (ACD) in the brain, is more active in the perinatal rat compared to adults. ACD has been found to share EtOH's behavioral effects. The general purpose of the present study was to assess ACD motivational and motor effects in newborn rats as a function of prenatal exposure to EtOH. Experiment 1 evaluated if ACD (0.35 μmol) or EtOH (0.02 μmol) supported appetitive conditioning in newborn pups prenatally exposed to EtOH. Experiment 2 tested if prenatal alcohol exposure modulated neonatal susceptibility to ACD's motor effects (ACD dose: 0, 0.35 and 0.52 μmol). Experiment 1 showed that EtOH and ACD supported appetitive conditioning independently of prenatal treatments. In Experiment 2, latency to display motor activity was altered only in neonates prenatally treated with water and challenged with the highest ACD dose. Prenatal EtOH experience results in tolerance to ACD's motor activity effects. These results show early susceptibility to ACD's appetitive effects and attenuation of motor effects as a function of prenatal history with EtOH, within a stage in development where brain ACD production seems higher than later in life. PMID:23785319

  12. Spectroscopic analysis, AIM, NLO and VCD investigations of acetaldehyde thiosemicarbazone using quantum mechanical simulations

    NASA Astrophysics Data System (ADS)

    Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Govindarajan, M.; Gnanamuthu, S. Joshua; Pandian, G. V.

    2016-08-01

    The prepared Acetaldehyde thiosemicarbazone (ATSC) have been investigated by both the experimental and theoretical methods; through this work, the essentiality of elucidation of molecular fragments source linear and non-linear optical properties was explored. The stability of the structure and entire calculations have been performed on HF and B3LYP methods with 6-311++G(d,p) level of basis set. The Mulliken charge profile, electronic, optical and hyper polarizability analyses have been carried out in order to evaluate nonlinear optical (NLO) performance of the present compound. The exact optical location of the ATSC was determined by executing UV-Visible calculations on TDSCF method. The existence of the molecular group for the inducement and tuning of NLO properties were thoroughly investigated by performing fundamental vibrational investigation. The optical energy transformation among frontier molecular levels has been described in UV-Visible region. The Gibbs energy coefficient of thermodynamic functions was monitored in different temperature and it was found constant irrespective of temperatures. The appearance of different chemical environment of H and C was monitored from the 1H and 13C NMR spectra. The vibrational optical polarization characteristics with respect to molecular composition in the compound have been studied by VCD spectrum. The bond critical point, Laplacian of electron density, electron kinetic energy density and total electron energy density have calculated and analysed using AIM study.

  13. Conversion of ethanol to acetaldehyde by human placental homogenates and villi in vitro

    SciTech Connect

    Blomquist, C.H.; Lindemann, N.J.; Hakanson, E.Y.

    1986-03-01

    The authors have previously reported that placental villi in vitro metabolize acetaldehyde (Ach), and that Ach forms adducts with placental subcellular fractions. In the experiments reported here the authors have investigated the capacity of placental homogenates and villi to generate Ach from ethanol (EtOH). When placental homogenates (0.5 g wet weight) prepared in 50 mM Tris. pH 7.5, were incubated with 20 ..mu..M (1-/sup 14/C)ethanol and an NADP- generating system, Ach was formed at the rate of 0.18 nmol/h/g wet weight of tissue, based on counts trappable with semicarbazide. NAD was as effective as NADP. Omission of cofactor resulted in a 69% decrease in activity. The addition of a human serum ultrafiltrate (25,000 m.w. cut-off) to 20% had no effect on Ach formation, whole serum at 20% reduced reaction by 60%. Sodium azide at 40 mM completely abolished Ach formation, 1,10-phenanthroline at 0.4 mM inhibited approximately 50%. In contrast, no Ach formation was detected when 1.0-g fragments of villous tissue were incubated with 20 ..mu..M (1-/sup 14/C)EtOH. The data suggest that villous tissue is capable of Ach formation by a catalase-like activity, but the capacity of intact villi for EtOH oxidation is low.

  14. Behavioral and biochemical evidence of the role of acetaldehyde in the motivational effects of ethanol

    PubMed Central

    Peana, Alessandra T.; Acquas, Elio

    2013-01-01

    Since Chevens' report, in the early 50's that his patients under treatment with the aldehyde dehydrogenase inhibitor, antabuse, could experience beneficial effects when drinking small volumes of alcoholic beverages, the role of acetaldehyde (ACD) in the effects of ethanol has been thoroughly investigated on pre-clinical grounds. Thus, after more than 25 years of intense research, a large number of studies have been published on the motivational properties of ACD itself as well as on the role that ethanol-derived ACD plays in the effects of ethanol. Accordingly, in particular with respect to the motivational properties of ethanol, these studies were developed following two main strategies: on one hand, were aimed to challenge the suggestion that also ACD may exert motivational properties on its own, while, on the other, with the aid of enzymatic manipulations or ACD inactivation, were aimed to test the hypothesis that ethanol-derived ACD might have a role in ethanol motivational effects. Furthermore, recent evidence significantly contributed to highlight, as possible mechanisms of action of ACD, its ability to commit either dopaminergic and opioidergic transmission as well as to activate the Extracellular signal Regulated Kinase cascade transduction pathway in reward-related brain structures. In conclusion, and despite the observation that ACD seems also to have inherited the elusive nature of its parent compound, the behavioral and biochemical evidence reviewed points to ACD as a neuroactive molecule able, on its own and as ethanol metabolite, to exert motivational effects. PMID:23874276

  15. Relationship of O2 Photodesorption in Photooxidation of Acetone on TiO2

    SciTech Connect

    Henderson, Michael A.

    2008-07-31

    Organic photooxidation on TiO2 invariably involves the coexistence of organic species with oxygen on the surface at the same time. In the case of acetone and oxygen, both species exhibit their own interesting photochemistry on TiO2, but interdependences between the two are not understood. In this study, a rutile TiO2(110) surface possessing 7% surface oxygen vacancy sites is used as a model surface to probe the relationship between O2 photodesorption and acetone photodecomposition. Temperature programmed desorption (TPD) and photon stimulated desorption (PSD) measurements indicate that coadsorbed oxygen is essential to acetone photodecomposition on this surface, however the form of oxygen (molecular and dissociative) is not known. The first steps in acetone photodecomposition on TiO2(110) involve thermal activation with oxygen to form an acetone diolate ((CH3)2COO) species followed by photochemical decomposition to adsorbed acetate (CH3COO) and an ejected CH3 radical that is detected in PSD. Depending on the surface conditions, O2 PSD is also observed during the latter process. However, the time scales for the two PSD events (CH3 and O2) are quite different, withthe former occurring at ~10 times faster than the latter. By varying the preheating conditions or performing pre-irradiation on an O2 exposed surface, it becomes clear that the two PSD events are uncorrelated. That is, the O2 species responsible for O2 PSD is not a significant participant in the photochemistry of acetone on TiO2(110) and likely originates from a minority form of O2 on the surface. The CH3 and O2 PSD events do not appear to be in competition with each other suggesting either that ample charge carriers exist under the experimental conditions employed or that different charge carriers or excitation mechanisms are involved.

  16. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, October 1, 1996--December 30, 1996

    SciTech Connect

    1997-03-01

    A series of MgO-based Cu catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. The bulk composition of the catalyst has been measured by atomic absorption (AA) analysis and the Cu dispersion has been determined by N{sub 2}O titration at 363 K. Kinetic studies of ethanol coupling reactions on Cu{sub 0.5}Mg{sub 5}CeO{sub x} and 1.0 wt % K-Cu{sub 0.5}Mg{sub 5}CeO{sub x} catalyst indicates that at similar steady-state acetaldehyde concentrations, the presence of K increases the rates of base-catalyzed aldol coupling reactions to acetone and butyraldehyde. Aldol coupling chain growth reaction rates on 1.2 wt % K-Cu{sub 7.5}Mg{sub 5}CeO{sub x} are higher than on 1.0 wt % K-Cu{sub 0.5}Mg{sub 5}CeO{sub x} even though basic site densities are similar on both samples, suggesting that Cu metal sites are also involved in rate-determining steps required for condensation reactions. Cu appears to enhance the desorption of H{sub 2} via the migration of H species from basic to Cu sites and makes the basic sites available for subsequent C-H bond activation steps. Addition of CO{sub 2} decreases the rate of base-catalyzed chain growth reaction to acetone, but does not affect the rate of ethanol dehydrogenation reaction on Cu metal sites

  17. Selective photocatalytic reduction of CO2 to methanol in CuO-loaded NaTaO3 nanocubes in isopropanol

    PubMed Central

    Xiang, Tianyu; Chen, Jingshuai; Wang, Yuwen; Yin, Xiaohong; Shao, Xiao

    2016-01-01

    Summary A series of NaTaO3 photocatalysts were prepared with Ta2O5 and NaOH via a hydrothermal method. CuO was loaded onto the surface of NaTaO3 as a cocatalyst by successive impregnation and calcination. The obtained photocatalysts were characterized by XRD, SEM, UV–vis, EDS and XPS and used to photocatalytically reduce CO2 in isopropanol. This worked to both absorb CO2 and as a sacrificial reagent to harvest CO2 and donate electrons. Methanol and acetone were generated as the reduction product of CO2 and the oxidation product of isopropanol, respectively. NaTaO3 nanocubes loaded with 2 wt % CuO and synthesized in 2 mol/L NaOH solution showed the best activity. The methanol and acetone yields were 137.48 μmol/(g·h) and 335.93 μmol/(g·h), respectively, after 6 h of irradiation. Such high activity could be attributed to the good crystallinity, morphology and proper amount of CuO loading, which functioned as reductive sites for selective formation of methanol. The reaction mechanism was also proposed and explained by band theory. PMID:27335766

  18. Engineering Escherichia coli for methanol conversion.

    PubMed

    Müller, Jonas E N; Meyer, Fabian; Litsanov, Boris; Kiefer, Patrick; Potthoff, Eva; Heux, Stéphanie; Quax, Wim J; Wendisch, Volker F; Brautaset, Trygve; Portais, Jean-Charles; Vorholt, Julia A

    2015-03-01

    Methylotrophic bacteria utilize methanol and other reduced one-carbon compounds as their sole source of carbon and energy. For this purpose, these bacteria evolved a number of specialized enzymes and pathways. Here, we used a synthetic biology approach to select and introduce a set of "methylotrophy genes" into Escherichia coli based on in silico considerations and flux balance analysis to enable methanol dissimilation and assimilation. We determined that the most promising approach allowing the utilization of methanol was the implementation of NAD-dependent methanol dehydrogenase and the establishment of the ribulose monophosphate cycle by expressing the genes for hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi). To test for the best-performing enzymes in the heterologous host, a number of enzyme candidates from different donor organisms were selected and systematically analyzed for their in vitro and in vivo activities in E. coli. Among these, Mdh2, Hps and Phi originating from Bacillus methanolicus were found to be the most effective. Labeling experiments using (13)C methanol with E. coli producing these enzymes showed up to 40% incorporation of methanol into central metabolites. The presence of the endogenous glutathione-dependent formaldehyde oxidation pathway of E. coli did not adversely affect the methanol conversion rate. Taken together, the results of this study represent a major advancement towards establishing synthetic methylotrophs by gene transfer.

  19. The bi-directional exchange of oxygenated VOCs between a loblolly pine (Pinus taeda) plantation and the atmosphere

    NASA Astrophysics Data System (ADS)

    Karl, T.; Harley, P.; Guenther, A.; Rasmussen, R.; Baker, B.; Jardine, K.; Nemitz, E.

    2005-11-01

    Using new in-situ field observations of the most abundant oxygenated VOCs (methanol, acetaldehyde, acetone, C3/C4 carbonyls, MVK+MAC and acetic acid) we were able to constrain emission and deposition patterns above and within a loblolly pine (Pinus taeda) plantation with a sweetgum (Liquidambar styraciflua) understory. During the day canopy scale measurements showed significant emission of methanol and acetone, while methyl vinyl ketone and methacrolein, acetaldehyde and acetic acid were mainly deposited during the day. All oxygenated compounds exhibited strong losses during the night that could not be explained by conventional dry deposition parameterizations. Accompanying leaf level measurements indicated substantial methanol and acetone emissions from loblolly pine. The exchange of acetaldehyde was more complex. Laboratory measurements made on loblolly pine needles indicated that acetaldehyde may be either emitted or taken up depending on ambient concentrations, with the compensation point increasing exponentially with temperature, and that mature needles tended to emit more acetaldehyde than younger needles. Canopy scale measurements suggested mostly deposition. Short-term (approx. 2 h) ozone fumigation in the laboratory had no detectable impact on post-exposure emissions of methanol and acetone, but decreased the exchange rates of acetaldehyde. The emission of a variety of oxygenated compounds (e.g. carbonyls and alcohols) was triggered or significantly enhanced during laboratory ozone fumigation experiments. These results suggest that higher ambient ozone levels in the future might enhance the biogenic contribution of some oxygenated compounds. Those with sufficiently low vapor pressures may potentially influence secondary organic aerosol growth. Compounds recently hypothesized to be primarily produced in the canopy atmosphere via ozone plus terpenoid-type reactions can also originate from the oxidation reaction of ozone with leaf surfaces and inside the leaf

  20. The bi-directional exchange of oxygenated VOCs between a loblolly pine (Pinus taeda) plantation and the atmosphere

    NASA Astrophysics Data System (ADS)

    Karl, T.; Harley, P.; Baker, B.; Jardine, K.; Nemitz, E.; Guenther, A.

    2005-08-01

    Using new in-situ field observations of the most abundant oxygenated VOCs (methanol, acetaldehyde, acetone, C3/C4 carbonyls, MVK+MAC and acetic acid) we were able to constrain emission and deposition patterns above and within a loblolly pine (Pinus taeda) plantation with a sweetgum (Liquidambar styraciflua) understory. Canopy scale measurements showed significant emission of methanol and acetone, while MVK+MAC, acetaldehyde and acetic acid were mainly deposited during the day. All oxygenated compounds exhibited strong losses during the night that could not be explained by conventional dry deposition parameterizations. Accompanying leaf level measurements indicated that methanol and acetone were primarily emitted from loblolly pine. The exchange of acetaldehyde was more complex. Laboratory measurements made on loblolly pine needles indicated that acetaldehyde may be either emitted or taken up depending on ambient concentrations, with the compensation point increasing exponentially with temperature, and that older needles tended to emit more acetaldehyde than younger needles. Canopy scale measurements suggested mostly deposition. Short-time (approx. 2 h) ozone fumigation had no detectable impact on post-exposure emissions of methanol and acetone, but modified the exchange rates of acetaldehyde. The emission of a variety of oxygenated compounds (e.g. carbonyls and alcohols) was triggered or significantly enhanced during ozone fumigation. These results suggest that increasing ozone levels in the future might enhance the biogenic contribution of some oxygenated compounds; those with sufficiently low vapor pressures may potentially influence secondary organic aerosol growth. Compounds recently hypothesized to be primarily produced in the canopy atmosphere via ozone plus terpenoid-type reactions can also originate from the reaction of ozone with leaf surfaces. This needs to be taken into account when scaling up very reactive biogenic compounds.

  1. Ion-paired extraction of cephalosporins in acetone prior to their analysis by capillary liquid chromatography in environmental water and meat samples.

    PubMed

    Quesada-Molina, Carolina; García-Campaña, Ana M; del Olmo-Iruela, Monsalud

    2013-10-15

    Ion-pair extraction of cephalosporins from aqueous solution into acetone by the addition of ammonium sulfate to a 1:2 (v/v) acetone-water solvent was carried out followed by their determination using reversed-phase capillary liquid chromatography. The analytes included are cephoperazone, cefquinome, cephalexin, cephapirin, cephaloniun, cephamandole, cephazolin and cephadroxile. In order to form the ion-pair, hexadecyltrimethylammonium bromide (CTAB) was selected as cationic ion-pairing agent at a concentration of 0.9 mM using 10mM phosphate buffer at pH 8 as the optimum condition for the aqueous solution. The applied methodology, named salting-out assisted liquid/liquid extraction (SALLE) involves the use of 1.25 g of ammonium sulfate as salting-out agent. The separation of cephalosporins using a Luna C18 (150 mm × 0.3mm, 5 µm, 100 Å) column was achieved under the following conditions: a gradient program combining solvent A (0.1% formic acid in water, pH 4) and solvent B (acetonitrile-methanol (50:50, v/v)), at a flow rate of 20 µl min(-1), column temperature 35°C and injection volume 7 µl with UV detection at 250 nm. The limits of quantification for the studied compounds were between 4.3 and 22.7 μg/L for water samples and 4.1 and 73.3 μg/kg in the case of beef samples, lower than the maximum residue limits permitted by the EU for this kind of food. The developed methodology has demonstrated its suitability for the analysis of these widely applied antibiotics in environmental water and meat samples, including beef and pork muscle, with high sensitivity, precision and satisfactory recoveries.

  2. Application of acetone acetals as water scavengers and derivatization agents prior to the gas chromatographic analysis of polar residual solvents in aqueous samples.

    PubMed

    van Boxtel, Niels; Wolfs, Kris; Van Schepdael, Ann; Adams, Erwin

    2015-12-18

    The sensitivity of gas chromatography (GC) combined with the full evaporation technique (FET) for the analysis of aqueous samples is limited due to the maximum tolerable sample volume in a headspace vial. Using an acetone acetal as water scavenger prior to FET-GC analysis proved to be a useful and versatile tool for the analysis of high boiling analytes in aqueous samples. 2,2-Dimethoxypropane (DMP) was used in this case resulting in methanol and acetone as reaction products with water. These solvents are relatively volatile and were easily removed by evaporation enabling sample enrichment leading to 10-fold improvement in sensitivity compared to the standard 10μL FET sample volumes for a selection of typical high boiling polar residual solvents in water. This could be improved even further if more sample is used. The method was applied for the determination of residual NMP in an aqueous solution of a cefotaxime analogue and proved to be considerably better than conventional static headspace (sHS) and the standard FET approach. The methodology was also applied to determine trace amounts of ethylene glycol (EG) in aqueous samples like contact lens fluids, where scavenging of the water would avoid laborious extraction prior to derivatization. During this experiment it was revealed that DMP reacts quantitatively with EG to form 2,2-dimethyl-1,3-dioxolane (2,2-DD) under the proposed reaction conditions. The relatively high volatility (bp 93°C) of 2,2-DD makes it possible to perform analysis of EG using the sHS methodology making additional derivatization reactions superfluous.

  3. Advanced direct methanol fuel cells. Final report

    SciTech Connect

    Hamdan, Monjid; Kosek, John A.

    1999-11-01

    The goal of the program was an advanced proton-exchange membrane (PEM) for use as the electrolyte in a liquid feed direct methanol fuel cell which provides reduced methanol crossover while simultaneously providing high conductivity and low membrane water content. The approach was to use a membrane containing precross-linked fluorinated base polymer films and subsequently to graft the base film with selected materials. Over 80 different membranes were prepared. The rate of methanol crossover through the advanced membranes was reduced 90%. A 5-cell stack provided stable performance over a 100-hour life test. Preliminary cost estimates predicted a manufacturing cost at $4 to $9 per kW.

  4. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-phenol reaction products and phenol, potassium sodium salts. 721.10238 Section 721.10238 Protection of..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  5. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-phenol reaction products and phenol, potassium sodium salts. 721.10238 Section 721.10238 Protection of..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  6. 40 CFR 721.10238 - Formaldehyde, polymers with acetone-phenol reaction products and phenol, potassium sodium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-phenol reaction products and phenol, potassium sodium salts. 721.10238 Section 721.10238 Protection of..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts. (a) Chemical substance..., polymers with acetone-phenol reaction products and phenol, potassium sodium salts (PMN P-09-147; CAS...

  7. Neurotoxicity associated with occupational exposure to acetone, methyl ethyl ketone, and cyclohexanone.

    PubMed

    Mitran, E; Callender, T; Orha, B; Dragnea, P; Botezatu, G

    1997-01-01

    The neurotoxic effects of acetone, methyl ethyl ketone (MEK), and cyclohexanone on Romanian workers and the impact of those effects on industry environmental standards have been controversial subjects. To scientifically substantiate the standards, a study was conducted on three groups of workers to determine the changes induced by ketone solvents on the central and peripheral nervous systems. Groups of exposed workers and matched controls were studied for each solvent: acetone, 71 exposed and 86 controls from a coin printing factory; MEK, 41 exposed and 63 controls from a cable factory; and cyclohexanone, 75 exposed and 85 controls from a furniture factory. The subjects' mean age was 36 years. The mean length of exposure was 14 years. Study participants completed a questionnaire, responded to questions about alcohol consumption, submitted to a clinical examination, submitted samples for identification of biological exposure markers, and underwent motor nerve conduction velocity and neurobehavioral tests. Results showed that workers exposed to acetone were most affected in terms of human performance and evidence of neurotoxicity, followed by workers exposed to MEK and workers exposed to cyclohexanone. On the basis of the results, it was proposed that the 6-hr permissible exposure limits for acetone, MEK, and cyclohexanone be reduced to less than 500, 200, and 150 mg/m3, respectively.

  8. A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

    PubMed

    Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

    2015-11-01

    Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed.

  9. Photooxidation of Isopropanol and Acetone Using TiO(sub 2) Suspension and UV Light

    SciTech Connect

    El-Morsi, Taha; Nanny, Mark A.

    2004-03-31

    Small polar organic compounds such as alcohols, ketones and aldehydes are highly soluble and do not adsorb strongly to the TiO2 surface and, therefore, may be fairly resistant to photocatalytic degradation. Photodegradation of an aqueous solution of isopropanol and its resulting photodegradation product acetone was investigated as a function of TiO2 substrate concentrations and solution ionic strength and pH. In the presence of 2g/L TiO2, isopropanol completely disappeared within 3 hrs, resulting in the nearly complete transformation into acetone. Subsequent photodegradation of acetone occurred at a much slower rate and resulted in complete mineralization. Increasing the pH slightly decreased the photodegradation rate. Conversely, the degradation rate was enhanced slightly by increasing the ionic strength. The presence of tetranitromethane decreased the isopropanol degradation significantly. This result, combined with the minimal degree of adsorption of isopropanol and acetone onto the surface of the photocatalyst, suggests that the photodegradation pathway occurs via free OH radicals in bulk solution rather than on the catalyst surface.

  10. Chemical-specific adjustment factors for intraspecies variability of acetone toxicokinetics using a probabilistic approach.

    PubMed

    Mörk, Anna-Karin; Johanson, Gunnar

    2010-07-01

    Human health risk assessment has begun to depart from the traditional methods by replacement of the default assessment factors by more reasonable, data-driven, so-called chemical-specific adjustment factors (CSAFs). This study illustrates a scheme for deriving CSAFs in the general and occupationally exposed populations by quantifying the intraspecies toxicokinetic variability in surrogate dose using probabilistic methods. Acetone was used as a model substance. The CSAFs were derived by Monte Carlo simulation, combining a physiologically based pharmacokinetic model for acetone, probability distributions of the model parameters from a Bayesian analysis of male volunteer experimental data, and published distributions of physiological and anatomical parameters for females and children. The simulations covered how factors such as age, gender, endogenous acetone production, and fluctuations in workplace air concentration and workload influence peak and average acetone levels in blood, used as surrogate doses. According to the simulations, CSAFs of 2.1, 2.9, and 3.8 are sufficient to cover the differences in surrogate dose at the upper 90th, 95th, and 97.5th percentile, respectively, of the general population. However, higher factors were needed to cover the same percentiles of children. The corresponding CSAFs for the occupationally exposed population were 1.6, 1.8, and 1.9. The methodology presented herein allows for derivation of CSAFs not only for populations as a whole but also for subpopulations of interest. Moreover, various types of experimental data can readily be incorporated in the model. PMID:20400482

  11. Assessment of in situ butanol recovery by vacuum during acetone butanol ethanol (ABE) fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol fermentation is product limiting due to butanol toxicity to microbial cells. Butanol (boiling point: 118 deg C) boils at a greater temperature than water (boiling point: 100 deg C) and application of vacuum technology to integrated acetone-butanol-ethanol (ABE) fermentation and recovery may ...

  12. Synthesis and antimalarial activity of dihydroperoxides and tetraoxanes conjugated with bis(benzyl)acetone derivatives.

    PubMed

    Franco, Lucas Lopardi; de Almeida, Mauro Vieira; E Silva, Luiz Francisco Rocha; Vieira, Pedro Paulo Ribeiro; Pohlit, Adrian Martin; Valle, Marcelo Siqueira

    2012-05-01

    Dihydroperoxides and tetraoxanes derived from symmetrically substituted bis(arylmethyl)acetones were synthesized in modest to good yields using several methods. Three of these compounds exhibit an important in vitro antimalarial activity (1.0 μm ≤ IC(50)  ≤ 5.0 μm) against blood forms of the human malaria parasite Plasmodium falciparum.

  13. NOX2 amplifies acetaldehyde-mediated cardiomyocyte mitochondrial dysfunction in alcoholic cardiomyopathy.

    PubMed

    Brandt, Moritz; Garlapati, Venkata; Oelze, Matthias; Sotiriou, Efthymios; Knorr, Maike; Kröller-Schön, Swenja; Kossmann, Sabine; Schönfelder, Tanja; Morawietz, Henning; Schulz, Eberhard; Schultheiss, Heinz-Peter; Daiber, Andreas; Münzel, Thomas; Wenzel, Philip

    2016-01-01

    Alcoholic cardiomyopathy (ACM) resulting from excess alcohol consumption is an important cause of heart failure (HF). Although it is assumed that the cardiotoxicity of the ethanol (EtOH)-metabolite acetaldehyde (ACA) is central for its development and progression, the exact mechanisms remain obscure. Murine cardiomyocytes (CMs) exposed to ACA or EtOH showed increased superoxide (O2(•-)) levels and decreased mitochondrial polarization, both being normalized by NADPH oxidase (NOX) inhibition. C57BL/6 mice and mice deficient for the ACA-degrading enzyme mitochondrial aldehyde dehydrogenase (ALDH-2(-/-)) were fed a 2% EtOH diet for 5 weeks creating an ACA-overload. 2% EtOH-fed ALDH-2(-/-) mice exhibited a decreased cardiac function, increased heart-to-body and lung-to-body weight ratios, increased cardiac levels of the lipid peroxidation product malondialdehyde (MDA) as well as increased NOX activity and NOX2/glycoprotein 91(phox) (NOX2/gp91(phox)) subunit expression compared to 2% EtOH-fed C57BL/6 mice. Echocardiography revealed that ALDH-2(-/-)/gp91(phox-/-) mice were protected from ACA-overload-induced HF after 5 weeks of 2% EtOH-diet, demonstrating that NOX2-derived O2(•-) contributes to the development of ACM. Translated to human pathophysiology, we found increased gp91(phox) expression in endomyocardial biopsies of ACM patients. In conclusion, ACM is promoted by ACA-driven mitochondrial dysfunction and can be improved by ablation of NOX2/gp91(phox). NOX2/gp91(phox) therefore might be a potential pharmacological target to treat ACM. PMID:27624556

  14. Density functional theory study of acetaldehyde hydrodeoxygenation on MoO3

    SciTech Connect

    Mei, Donghai; Karim, Ayman M.; Wang, Yong

    2011-04-06

    Periodic spin-polarized density functional theory calculations were performed to investigate acetaldehyde (CH3CHO) hydrodeoxygenation on the reduced molybdenum trioxide (MoO3) surface. The perfect O-terminated α-MoO3(010) surface is reduced to generate an oxygen defect site in the presence of H2. H2 dissociatively adsorbs at the surface oxygen sites forming two surface hydroxyls, which can recombine into a water molecule weakly bound at the Mo site. A terminal oxygen (Ot) defect site thus forms after water desorption. CH3CHO adsorbs at the O-deficient Mo site via either the sole O-Mo bond or the O-Mo and the C-O double bonds. The possible reaction pathways of the adsorbed CH3CHO with these two configurations were thoroughly examined using the dimer searching method. Our results show that the ideal deoxygenation of CH3CHO leading to ethylene (C2H4) on the reduced MoO3(010) surface is feasible. The adsorbed CH3CHO first dehydrogenate into CH2CHO by reacting with a neighboring terminal Ot. The hydroxyl (OtH) then hydrogenates CH2CHO into CH2CH2O to complete the hydrogen transfer cycle with an activation barrier of 1.39 eV. The direct hydrogen transfer from CH3CHO to CH2CH2O is unlikely due to the high barrier of 2.00 eV. The produced CH2CH2O readily decomposes into C2H4 that directly releases to the gas phase, and regenerates the Ot atom on the Mo site. As a result, the reduced MoO3(010) surface is reoxidized to the perfect MoO3(010) surface after CH3CHO deoxygenation. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  15. Assignment, Fit, and Theoretical Discussion of the v10 Band of Acetaldehyde Near 509 cm-1

    SciTech Connect

    Kleiner, Isabelle; Moazzen-Ahmadi, N.; McKellar, A.R. W.; Blake, Thomas A.; Sams, Robert L.; Sharpe, Steven W.; Moruzzi, Giovanni; Hougen, Jon T.

    2008-12-01

    The lowest small-amplitude vibration in acetaldehyde (CH3CHO) is the in-plane aldehyde scissors mode v10 at 509 cm-1. This mode lies about 175 cm-1 above the top of the barrier to internal rotation of the methyl group and is relatively well separated from other small-amplitude vibrational states (the next fundamental occurring more than 250 cm-1 higher). It thus provides an excellent example of an isolated small-amplitude fundamental (bright state) embedded in a bath of dark states. Since the bath states at these energies are not too dense, and since they arise purely from states of the large-amplitude torsional vibration of the methyl rotor, a detailed spectroscopic analysis of interactions between the bright state and the bath states should be possible. This paper represents the first step toward that goal. We have assigned several thousand transitions in the v10 band (J < 28, K< 12), and have carried out a simultaneous fit of 2400 of these transitions (J < 15, K< 9) with over 8100 transitions to the torsional bath state levels. Three vibration-torsion interactions, which give rise to rather global level shifts of the order of 1 cm-1 in the v10 levels, have been identified and quantitatively fit. A number of vibration-torsion-rotation interactions, which give rise to localized (avoided-crossing) shifts in v10 have also been determined. The present analysis indicates the need for reliable spectroscopic information on more of the torsional bath states in the immediate vicinity of the v10 levels. Possible ways of obtaining such information in future studies are considered.

  16. Direct observation of roaming radicals in the thermal decomposition of acetaldehyde.

    SciTech Connect

    Sivaramakrishnan, R.; Michael, J. V.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

    2010-01-21

    The thermal dissociation of acetaldehyde has been studied with the reflected shock tube technique using H(D)-atom atomic resonance absorption spectrometry detection. The use of an unreversed light source yields extraordinarily sensitive H atom detection. As a result, we are able to measure both the total decomposition rate and the branching to radical versus molecular channels. This branching provides a direct measure of the contribution from the roaming radical mechanism since the contributions from the usual tight transition states are predicted by theory to be negligible. The experimental observations also provide a measure of the rate coefficient for H + CH{sub 3}CHO. Another set of experiments employing C{sub 2}H{sub 5}I as an H-atom source provides additional data for this rate coefficient that extends to lower temperature. An evaluation of the available experimental results for H + CH{sub 3}CHO can be expressed by a three-parameter Arrhenius expression as k = 7.66 x 10{sup -20}T{sup 2.75} exp((-486 K)/T) cm{sup 3} molecule{sup -1} s{sup -1} (298-1415 K). Analogous experiments employing C{sub 2}D{sub 5}I as a D-atom source allow for the study of the isotopically substituted reaction. The present experiments are the only direct measure for this reaction rate constant, and the results can be expressed by an Arrhenius expression as k = 5.20 x 10{sup -10} exp((-4430 K)/T) cm{sup 3} molecule{sup -1} s{sup -1} (1151-1354 K). The H/D + CH{sub 3}CHO reactions are also studied with ab initio transition-state theory, and the results are in remarkably good agreement with the current experimental data.

  17. Effect of Acetaldehyde Intoxication and Withdrawal on NPY Expression: Focus on Endocannabinoidergic System Involvement.

    PubMed

    Plescia, Fulvio; Brancato, Anna; Marino, Rosa Anna Maria; Vita, Carlotta; Navarra, Michele; Cannizzaro, Carla

    2014-01-01

    Acetaldehyde (ACD), the first alcohol metabolite, plays a pivotal role in the rewarding, motivational, and addictive properties of the parental compound. Many studies have investigated the role of ACD in mediating neurochemical and behavioral effects induced by alcohol administration, but very little is known about the modulation of neuropeptide systems following ACD intoxication and withdrawal. Indeed, the neuropeptide Y (NPY) system is altered during alcohol withdrawal in key regions for cerebrocortical excitability and neuroplasticity. The primary goal of this research was to investigate the effects of ACD intoxication and withdrawal by recording rat behavior and by measuring NPY immunoreactivity in hippocampus and NAcc, two brain regions mainly involved in processes which encompass neuroplasticity in alcohol dependence. Furthermore, on the basis of the involvement of endocannabinoidergic system in alcohol and ACD reinforcing effects, the role of the selective CB1 receptor antagonist AM281 in modulating NPY expression during withdrawal was assessed. Our results indicate that (i) ACD intoxication induced a reduction in NPY expression in hippocampus and NAcc; (ii) symptoms of physical dependence, similar to alcohol's, were scored at 12 h from the last administration of ACD; and (iii) NPY levels increased in early and prolonged acute withdrawal in both brain regions examined. The administration of AM281 was able to blunt signs of ACD-induced physical dependence, to modulate NPY levels, and to further increase NPY expression during ACD withdrawal both in hippocampus and NAcc. In conclusion, the present study shows that complex plastic changes take place in NPY system during ACD intoxication and subsequent withdrawal in rat hippocampal formation and NAcc. The pharmacological inhibition of CB1 signaling could counteract the neurochemical imbalance associated with ACD, and alcohol withdrawal, likely boosting the setting up of homeostatic functional recovery.

  18. Sequential acetaldehyde production, lipid peroxidation, and fibrogenesis in micropig model of alcohol-induced liver disease.

    PubMed

    Niemelä, O; Parkkila, S; Ylä-Herttuala, S; Villanueva, J; Ruebner, B; Halsted, C H

    1995-10-01

    The pathogenesis of alcohol-induced liver disease involves the adverse effects of ethanol metabolites and oxidative tissue injury. Previous studies indicated that covalent protein adducts with reactive aldehydes may be formed in alcohol consumers. To study the role of such protein adducts in the development of liver injury, we examined the sequential appearances of adducts of the ethanol metabolite acetaldehyde (AA) and of two products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxynonenol (HNE), in ethanol-fed micropigs. Immunohistochemical stainings using specific antibodies that recognize epitopes of each adduct were performed from liver biopsy specimens obtained at 1, 5, and 12 months from micropigs fed either control diet (n = 5) or ethanol-containing diets (n = 5). After 1 month on the ethanol diet, AA and MDA adducts were observed primarily in the perivenous regions co-localizing with each other and coinciding with increased concentrations of serum aminotransferase markers of liver injury. HNE adducts were usually less intense and more diffuse, and were also seen in some biopsy specimens from control animals. Although the most intense staining reactions at 5 months remained in zone 3, a more widespread distribution was usually seen together with increased evidence of steatonecrosis and focal inflammation. In terminal biopsies at 12 months, perivenous fibrosis was present in three of five biopsy specimens. More extensive pericentral and intralobular fibrosis was noted in one micropig fed ethanol for 21 months. These studies demonstrate that covalent adducts of proteins with reactive aldehydes are formed in early phases of alcohol-induced liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. NOX2 amplifies acetaldehyde-mediated cardiomyocyte mitochondrial dysfunction in alcoholic cardiomyopathy

    PubMed Central

    Brandt, Moritz; Garlapati, Venkata; Oelze, Matthias; Sotiriou, Efthymios; Knorr, Maike; Kröller-Schön, Swenja; Kossmann, Sabine; Schönfelder, Tanja; Morawietz, Henning; Schulz, Eberhard; Schultheiss, Heinz-Peter; Daiber, Andreas; Münzel, Thomas; Wenzel, Philip

    2016-01-01

    Alcoholic cardiomyopathy (ACM) resulting from excess alcohol consumption is an important cause of heart failure (HF). Although it is assumed that the cardiotoxicity of the ethanol (EtOH)-metabolite acetaldehyde (ACA) is central for its development and progression, the exact mechanisms remain obscure. Murine cardiomyocytes (CMs) exposed to ACA or EtOH showed increased superoxide (O2•−) levels and decreased mitochondrial polarization, both being normalized by NADPH oxidase (NOX) inhibition. C57BL/6 mice and mice deficient for the ACA-degrading enzyme mitochondrial aldehyde dehydrogenase (ALDH-2−/−) were fed a 2% EtOH diet for 5 weeks creating an ACA-overload. 2% EtOH-fed ALDH-2−/− mice exhibited a decreased cardiac function, increased heart-to-body and lung-to-body weight ratios, increased cardiac levels of the lipid peroxidation product malondialdehyde (MDA) as well as increased NOX activity and NOX2/glycoprotein 91phox (NOX2/gp91phox) subunit expression compared to 2% EtOH-fed C57BL/6 mice. Echocardiography revealed that ALDH-2−/−/gp91phox−/− mice were protected from ACA-overload-induced HF after 5 weeks of 2% EtOH-diet, demonstrating that NOX2-derived O2•− contributes to the development of ACM. Translated to human pathophysiology, we found increased gp91phox expression in endomyocardial biopsies of ACM patients. In conclusion, ACM is promoted by ACA-driven mitochondrial dysfunction and can be improved by ablation of NOX2/gp91phox. NOX2/gp91phox therefore might be a potential pharmacological target to treat ACM. PMID:27624556

  20. The influence of B-complex vitamins upon the prolongation of prothrombin time by acetaldehyde.

    PubMed

    Catazaro, Jonathan R; Brecher, Arthur S

    2013-07-01

    Alcoholism plays a major role in the insufficient utilization or deficiency of the vitamin B-complex molecules, and the pathologies resulting therefrom. Thiamine, pyridoxamine, and folic acid, each contain primary amine functional groups, whereas nicotinamide and vitamin B12 contain amide groups, each of which are potential reactants with acetaldehyde (AcH), the primary intermediate in the metabolism of ethanol. In this current study, it is reported that prothrombin time (PT), which is prolonged in a fraction of the alcoholic population, can be modified (in the laboratory) when several B-complex vitamins and AcH are added successively to human plasma or are premixed prior to the addition to plasma. Particularly, thiamine, pyridoxamine, and folic acid, at 0.01 mol/l, when added successively with 44.7 mmol/l AcH to plasma, or when premixed prior to addition to plasma, produced a marked reduction in the anticoagulant effect of AcH. Nicotinamide had no effect on PT nor did mixtures with AcH effect PT. However, NAD, which contains a primary amine in its AMP moiety, reacted with AcH, lowering the latter's anticoagulant activity upon addition to plasma. Vitamin B12 did not affect PT. Interestingly, successive mixtures of vitamin B12 and AcH to plasma resulted in a small but statistically significant increase (P≤0.05) in the anticoagulant effect of AcH, whereas premixtures had no statistically significant effect (P>0.05). The decrease in anticoagulant activity of AcH in the presence of B-complex vitamins and NAD suggests that the primary amines in these molecules may form Schiff bases with AcH, thereby lowering both the free AcH concentration as well as the ability of the free vitamins/coenzymes to partake in essential physiological reactions.