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Sample records for acetaldehyde

  1. Acetaldehyde and gastric cancer.

    Salaspuro, Mikko

    2011-04-01

    Aldehyde dehydrogenase (ALDH2) and alcohol dehydrogenase (ADH) gene polymorphisms associating with enhanced acetaldehyde exposure and markedly increased cancer risk in alcohol drinkers provide undisputable evidence for acetaldehyde being a local carcinogen not only in esophageal but also in gastric cancer. Accordingly, acetaldehyde associated with alcoholic beverages has recently been classified as a Group 1 carcinogen to humans. Microbes are responsible for the bulk of acetaldehyde production from ethanol both in saliva and Helicobacter pylori-infected and achlorhydric stomach. Acetaldehyde is the most abundant carcinogen in tobacco smoke and it readily dissolves into saliva during smoking. Many foodstuffs and 'non-alcoholic' beverages are important but unrecognized sources of local acetaldehyde exposure. The cumulative cancer risk associated with increasing acetaldehyde exposure suggests the need for worldwide screening of the acetaldehyde levels of alcoholic beverages and as well of the ethanol and acetaldehyde of food produced by fermentation. The generally regarded as safe status of acetaldehyde should be re-evaluated. The as low as reasonably achievable principle should be applied to the acetaldehyde of alcoholic and non-alcoholic beverages and food. Risk groups with ADH-and ALDH2 gene polymorphisms, H. pylori infection or achlorhydric atrophic gastritis, or both, should be screened and educated in this health issue. L-cysteine formulations binding carcinogenic acetaldehyde locally in the stomach provide new means for intervention studies. PMID:21401890

  2. Acetaldehyde adducts with hemoglobin.

    Stevens, V.J.; Fantl, W J; Newman, C B; Sims, R V; Cerami, A.; Peterson, C M

    1981-01-01

    Clinical studies on the minor hemoglobins (hemoglobin A1a-c) have suggested that a novel adduct may form in people abusing alcohol. Such patients were found to have an elevated concentration of minor hemoglobins, but normal or subnormal amounts of glycosylated hemoglobin (hemoglobin A1c) as determined by radioimmunoassay, Acetaldehyde, a reactive metabolite of ethanol, was postulated to form adducts with hemoglobin A that change its chromatographic properties. At physiological concentrations,...

  3. Acetaldehyde in the Alaskan subarctic snow pack

    F. Domine

    2009-09-01

    Full Text Available Acetaldehyde is a reactive intermediate in hydrocarbon oxidation. It is both emitted and taken up by snowpacks and photochemical and physical processes are probably involved. Understanding the reactivity of acetaldehyde in snow and its processes of physical and chemical exchanges requires the knowledge of its incorporation mechanism in snow crystals. We have performed a season-long study of the evolution of acetaldehyde concentrations in the subarctic snowpack near Fairbanks (65° N, central Alaska, which is subjected to a vigorous metamorphism due to persistent elevated temperature gradients in the snowpack, between 20 and 200°C m−1. The snowpack therefore almost entirely transforms into depth hoar. We have also analyzed acetaldehyde in a manipulated snowpack where temperature gradients were suppressed. Snow crystals there transformed much more slowly and their original shapes remained recognizable for months. The specific surface area of snow layers in both types of snowpacks was also measured. We deduce that acetaldehyde is not adsorbed onto the surface of snow crystals and that most of the acetaldehyde is probably not dissolved in the ice lattice of the snow crystals. We propose that most of the acetaldehyde measured is either trapped or dissolved within organic aerosol particles trapped in snow, or that acetaldehyde is formed by the hydrolysis of organic precursors contained in organic aerosols trapped in the snow, when the snow is melted for analysis. These precursors are probably aldehyde polymers formed within the aerosol particles by acid catalysis, but might also be biological molecules. In a laboratory experiment, acetaldehyde-di-n-hexyl acetal, representing a potential acetaldehyde precursor, was subjected to our analytical procedure and reacted to form acetaldehyde. This confirms our suggestion that acetaldehyde in snow could be produced during the melting of snow for analysis.

  4. Acetaldehyde Adducts in Alcoholic Liver Disease

    Mashiko Setshedi

    2010-01-01

    Full Text Available Chronic alcohol abuse causes liver disease that progresses from simple steatosis through stages of steatohepatitis, fibrosis, cirrhosis, and eventually hepatic failure. In addition, chronic alcoholic liver disease (ALD, with or without cirrhosis, increases risk for hepatocellular carcinoma (HCC. Acetaldehyde, a major toxic metabolite, is one of the principal culprits mediating fibrogenic and mutagenic effects of alcohol in the liver. Mechanistically, acetaldehyde promotes adduct formation, leading to functional impairments of key proteins, including enzymes, as well as DNA damage, which promotes mutagenesis. Why certain individuals who heavily abuse alcohol, develop HCC (7.2–15% versus cirrhosis (15–20% is not known, but genetics and co-existing viral infection are considered pathogenic factors. Moreover, adverse effects of acetaldehyde on the cardiovascular and hematologic systems leading to ischemia, heart failure, and coagulation disorders, can exacerbate hepatic injury and increase risk for liver failure. Herein, we review the role of acetaldehyde adducts in the pathogenesis of chronic ALD and HCC.

  5. Heterogeneous Interactions of Acetaldehyde and Sulfuric Acid

    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.

  6. Threshold photoelectron spectroscopy of acetaldehyde and acrolein

    Highlights: •High-resolution threshold photoelectron spectrum of acetaldehyde. •High-resolution threshold photoelectron spectrum of acrolein. •High-resolution total photoion yield spectrum of acetaldehyde. •High-resolution total photoion yield spectrum of acrolein. •Determination of vertical ionization potentials in acetaldehyde and acrolein. -- Abstract: High-resolution (6 meV and 12 meV) threshold photoelectron (TPE) spectra of acetaldehyde and acrolein (2-propenal) have been recorded over the valence binding energy region 10–20 eV, employing synchrotron radiation and a penetrating-field electron spectrometer. These TPE spectra are presented here for the first time. All of the band structures observed in the TPE spectra replicate those found in their conventional HeI photoelectron (PE) spectra. However, the relative band intensities are found to be dramatically different in the two types of spectra that are attributed to the different dominant operative formation mechanisms. In addition, some band shapes and their vertical ionization potentials are found to differ in the two types of spectra that are associated with the autoionization of Rydberg states in the two molecules

  7. Threshold photoelectron spectroscopy of acetaldehyde and acrolein

    Yencha, Andrew J., E-mail: ayencha@albany.edu [Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222 (United States); Siggel-King, Michele R.F. [Cockcroft Institute, Sci-Tech Daresbury, Warrrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); King, George C. [Department of Physics and Astronomy and Photon Science Institute, Manchester University, Manchester M13 9PL (United Kingdom); Malins, Andrew E.R. [Cockcroft Institute, Sci-Tech Daresbury, Warrrington WA4 4AD (United Kingdom); Eypper, Marie [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2013-04-15

    Highlights: •High-resolution threshold photoelectron spectrum of acetaldehyde. •High-resolution threshold photoelectron spectrum of acrolein. •High-resolution total photoion yield spectrum of acetaldehyde. •High-resolution total photoion yield spectrum of acrolein. •Determination of vertical ionization potentials in acetaldehyde and acrolein. -- Abstract: High-resolution (6 meV and 12 meV) threshold photoelectron (TPE) spectra of acetaldehyde and acrolein (2-propenal) have been recorded over the valence binding energy region 10–20 eV, employing synchrotron radiation and a penetrating-field electron spectrometer. These TPE spectra are presented here for the first time. All of the band structures observed in the TPE spectra replicate those found in their conventional HeI photoelectron (PE) spectra. However, the relative band intensities are found to be dramatically different in the two types of spectra that are attributed to the different dominant operative formation mechanisms. In addition, some band shapes and their vertical ionization potentials are found to differ in the two types of spectra that are associated with the autoionization of Rydberg states in the two molecules.

  8. Ethylene oxide and Acetaldehyde in hot cores

    Occhiogrosso, A; Herbst, E; Viti, S; Ward, M D; Price, S D; Brown, W A

    2014-01-01

    [Abridged] Ethylene oxide and its isomer acetaldehyde are important complex organic molecules because of their potential role in the formation of amino acids. Despite the fact that acetaldehyde is ubiquitous in the interstellar medium, ethylene oxide has not yet been detected in cold sources. We aim to understand the chemistry of the formation and loss of ethylene oxide in hot and cold interstellar objects (i) by including in a revised gas-grain network some recent experimental results on grain surfaces and (ii) by comparison with the chemical behaviour of its isomer, acetaldehyde. We test the code for the case of a hot core. The model allows us to predict the gaseous and solid ethylene oxide abundances during a cooling-down phase prior to star formation and during the subsequent warm-up phase. We can therefore predict at what temperatures ethylene oxide forms on grain surfaces and at what temperature it starts to desorb into the gas phase. The model reproduces the observed gaseous abundances of ethylene oxid...

  9. Acetaldehyde inhibition of protein synthesis in isolated rat pancreatic acini

    Exposure of isolated dispersed pancreatic acini to increasing concentrations of ethanol (5 to 500 mM) or acetaldehyde (0.5 to 100 mM) produced a progressive inhibition of [3H]leucine incorporation into both cellular (those remaining in the cell) and secretory (those released into the medium) proteins. Whereas 500 mM ethanol caused 90-95% inhibition in the synthesis of cellular and secretory proteins, the concentration of acetaldehyde needed to produce a similar inhibition was found to be 50 mM. All subsequent experiments were performed with 12.5 mM acetaldehyde, a concentration that consistently inhibited acinar protein synthesis by about 50%. The acetaldehyde-mediated inhibition of acinar protein synthesis was partially normalized when this metabolite was removed after 30 min during a 90-min incubation period. In the presence of acetaldehyde, the secretion of 3H-pulse-labeled proteins, but not amylase, trypsinogen, or chymotrypsinogen, was greatly depressed. Acetaldehyde also caused a marked reduction in [3H]uridine incorporation into acinar RNA. The entry of [3H]uridine, [3H]leucine, and [3H]aminoisobutyric acid into isolated acini was found to be slightly (15-25%) decreased by acetaldehyde. It is concluded that acetaldehyde exerts a direct toxic effect on isolated dispersed pancreatic acini as evidenced by diminution of both protein and RNA synthesis and decreased secretion of the newly synthesized proteins. This inhibitory effect of acetaldehyde could be partially reversed

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

    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.

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

    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...

  12. Mechanism of acetaldehyde-induced deactivation of microbial lipases

    Jaeger Karl E

    2011-02-01

    Full Text Available Abstract Background Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were sensitive toward acetaldehyde deactivation whereas others were insensitive; however, a general explanation of the acetaldehyde-induced inactivation mechanism is missing. Results Based on five microbial lipases from Candida rugosa, Rhizopus oryzae, Pseudomonas fluorescens and Bacillus subtilis we demonstrate that the protonation state of lysine ε-amino groups is decisive for their sensitivity toward acetaldehyde. Analysis of the diverse modification products of Bacillus subtilis lipases in the presence of acetaldehyde revealed several stable products such as α,β-unsaturated polyenals, which result from base and/or amino acid catalyzed aldol condensation of acetaldehyde. Our studies indicate that these products induce the formation of stable Michael-adducts at solvent-accessible amino acids and thus lead to enzyme deactivation. Further, our results indicate Schiff-base formation with acetaldehyde to be involved in crosslinking of lipase molecules. Conclusions Differences in stability observed with various commercially available microbial lipases most probably result from different purification procedures carried out by the respective manufacturers. We observed that the pH of the buffer used prior to lyophilization of the enzyme sample is of utmost importance. The mechanism of acetaldehyde-induced deactivation of microbial lipases involves the generation of α,β-unsaturated polyenals from acetaldehyde which subsequently form stable Michael-adducts with the

  13. Acetaldehyde-induced cytotoxicity involves induction of spermine oxidase at the transcriptional level.

    Uemura, Takeshi; Tanaka, Yuka; Higashi, Kyohei; Miyamori, Daisuke; Takasaka, Tomokazu; Nagano, Tatsuo; Toida, Toshihiko; Yoshimoto, Kanji; Igarashi, Kazuei; Ikegaya, Hiroshi

    2013-08-01

    Ethanol consumption causes serious liver injury including cirrhosis and hepatocellular carcinoma. Ethanol is metabolized mainly in the liver to acetic acid through acetaldehyde. We investigated the effect of ethanol and acetaldehyde on polyamine metabolism since polyamines are essential factors for normal cellular functions. We found that acetaldehyde induced spermine oxidase (SMO) at the transcriptional level in HepG2 cells. The levels and activities of ornithine decarboxylase (ODC) and spermidine/spermine acetyltransferase (SSAT) were not affected by acetaldehyde. Spermidine content was increased and spermine content was decreased by acetaldehyde treatment. Knockdown of SMO expression using siRNA reduced acetaldehyde toxicity. Acetaldehyde exposure increased free acrolein levels. An increase of acrolein by acetaldehyde was SMO dependent. Our results indicate that cytotoxicity of acetaldehyde involves, at least in part, oxidation of spermine to spermidine by SMO, which is induced by acetaldehyde. PMID:23707493

  14. Eclipsed Acetaldehyde as a Precursor for Producing Vinyl Alcohol

    Saadullah G. Aziz

    2012-11-01

    Full Text Available The MP2 and DFT/B3LYP methods at 6-311++G(d,p and aug-cc-pdz basis sets have been used to probe the origin of relative stability preference for eclipsed acetaldehyde over its bisected counterpart. A relative energy stability range of 1.02 to 1.20 kcal/mol, in favor of the eclipsed conformer, was found and discussed. An NBO study at these chemistry levels complemented these findings and assigned the eclipsed acetaldehyde preference mainly to the vicinal antiperiplanar hyperconjugative interactions. The tautomeric interconversion between the more stable eclipsed acetaldehyde and vinyl alcohol has been achieved through a four-membered ring transition state (TS. The obtained barrier heights and relative stabilities of eclipsed acetaldehyde and the two conformers of vinyl alchol at these model chemistries have been estimated and discussed.

  15. Photochemical and hot H atom reactions of acetaldehyde

    Photolysis and hot hydrogen atom reactions of acetaldehyde have been studied simultaneously not only with a cadmium but also with a zinc resonance lamp as the light source. Contrary to previous results, new products (acetone, ethanol, 2-propanol, ethyl acetoacetate, and diacetone alcohol) are identified in the photolysis of acetaldehyde. On the other hand, the principal products in decreasing order from the hot atom reaction with acetaldehyde have been established to be hydrogen, biacetyl, methane, carbon monoxide, and ethanol, whereas acetone and ethylene existed as minor products. A study of product quantum yields at 214 nm vs. various [CH3CHO]/[CH2S] ratios are reported. The formation of several unexpected products in these studies strongly suggested that the aldehyde functional group of acetaldehyde has an unsaturated character relative to the addition of both hydrogen atoms and methyl radicals. This latter new observation and accompanying mechanisms are discussed. 2 figures, 6 tables

  16. In vitro inhibition of 10-formyltetrahydrofolate dehydrogenase activity by acetaldehyde

    Mun, Ju-Ae; Doh, Eunjin; Min, Hyesun

    2008-01-01

    Alcoholism has been associated with folate deficiency in humans and laboratory animals. Previous study showed that ethanol feeding reduces the dehydrogenase and hydrolase activity of 10-formyltetrahydrofolate dehydrogenase (FDH) in rat liver. Hepatic ethanol metabolism generates acetaldehyde and acetate. The mechanisms by which ethanol and its metabolites produce toxicity within the liver cells are unknown. We purified FDH from rat liver and investigated the effect of ethanol, acetaldehyde an...

  17. Atmospheric Vinyl Alcohol to Acetaldehyde Tautomerization Revisited.

    Peeters, Jozef; Nguyen, Vinh Son; Müller, Jean-François

    2015-10-15

    The atmospheric oxidation of vinyl alcohol (VA) produced by photoisomerization of acetaldehyde (AA) is thought to be a source of formic acid (FA). Nevertheless, a recent theoretical study predicted a high rate coefficient k1(298 K) of ≈10(-14) cm(3) molecule(-1) s(-1) for the FA-catalyzed tautomerization reaction 1 of VA back into AA, which suggests that FA buffers its own production from VA. However, the unusually high frequency factor implied by that study prompted us to reinvestigate reaction 1 . On the basis of a high-level ab initio potential energy profile, we first established that transition state theory is applicable, and derived a k1(298 K) of only ≈2 × 10(-20) cm(3) molecule(-1) s(-1), concluding that the reaction is negligible. Instead, we propose and rationalize another important VA sink: its uptake by aqueous aerosol and cloud droplets followed by fast liquid-phase tautomerization to AA; global modeling puts the average lifetime by this sink at a few hours, similar to oxidation by OH. PMID:26722769

  18. Acetone and acetaldehyde determination in tomato juice by isotopic dilution

    Acetone and acetaldehyde content of tomato juice were determined by isotope dilution techniques. The juice is added to 14C labelled compounds, carried along by nitrogen at low pressure. The mixture of 2.4 dinitrophenylhydrazones obtained from volatile compounds is separated by thin layer chromatography on silica gel and then on alumina. A determination of radioactivity and concentration of acetone and acetaldehyde 2,4 dinitrophenylhydrazones obtained after separation and elution allow to calculate the content of these two compounds in the initial product with the same sample. This technique could be used for determination of methanol and ethanol after transformation in 3,5 dinitrobenzoates

  19. Effects of formaldehyde and acetaldehyde inhalation on rat pulmonary mechanics

    Saldiva, P.H.; do Rio Caldeira, M.P.; Massad, E.; Calheiros, D.F.; Cardoso, L.M.; Boehm, G.M.S.; Saldiva, C.D.

    1985-10-01

    Two groups of 12 male Wistar rats received either 243 ppm of acetaldehyde or 5.7 ppm of formaldehyde for 8 h a day, 5 days a week during 5 weeks. These levels represent three times the threshold limit values (TLV) for these substances in Brazilian legislation. The animals were evaluated by pulmonary function tests before and after exposure to the pollutants. The data obtained from these rats were compared with those of 12 controls, housed in identical conditions for the same length of time but breathing normal air. The results showed an increase of the functional residual capacity, residual volume, total lung capacity and respiratory frequency in the rats exposed to acetaldehyde atmosphere. The animals exposed to formaldehyde did not present pulmonary function alterations when compared with the controls. The damage caused by acetaldehyde to the peripheral regions of the lung parenchyma, affecting small airways or altering pulmonary elastic properties, is discussed. It is suggested that the Brazilian TLV for acetaldehyde (78 ppm) is not as safe as that for formaldehyde (1.6 ppm).

  20. [A gas chromatographic method for determining acetaldehyde in cadaver blood].

    Savich, V I; Valladares, Kh A; Gusakov, Iu A; Skachko, Z M

    1990-01-01

    Gas-chromatographic method of acetaldehyde detection in blood of subjects who died of alcoholic intoxication is suggested. Method is simple, does not require additional expenses, can be readily used in medicolegal practice and in difficult cases it may help the expert to make an objective conclusion on the cause of death. PMID:2087747

  1. Plant physiological and environmental controls over the exchange of acetaldehyde between forest canopies and the atmosphere

    K. Jardine

    2008-06-01

    Full Text Available We quantified fine scale sources and sinks of gas phase acetaldehyde in two forested ecosystems in the US. During the daytime, the upper canopy behaved as a net source while at lower heights, reduced emission rates or net uptake were observed. At night, uptake generally predominated thoughout the canopies. Net ecosystem emission rates were inversely related to foliar density which influenced the extinction of light and the acetaldehyde compensation point in the canopy. This is supported by branch level studies revealing much higher compensation points in the light than in the dark for poplar (Populus deltoides and holly oak (Quercus ilex implying a higher light/temperature sensitivity for acetaldehyde production relative to consumption. The view of stomata as the major pathway for acetaldehyde exchange is supported by strong linear correlations between branch transpiration rates and acetaldehyde exchange velocities for both species. In addition, natural abundance carbon isotope analysis of gas-phase acetaldehyde during poplar branch fumigation experiments revealed a significant kinetic isotope effect of 5.1±0.3‰, associated with the uptake of acetaldehyde. Similar experiments with dry dead poplar leaves showed no fractionation or uptake of acetaldehyde, confirming that this is only a property of living leaves. We suggest that acetaldehyde belongs to a potentially large list of plant metabolites where stomatal conductance can exert long term control over both emission and uptake rates due to the presence of both source(s and sink(s within the leaf which strongly buffer large changes in concentrations in the substomatal airspace due to changes in stomatal conductance. We conclude that the exchange of acetaldehyde between plant canopies and the atmosphere is fundamentally controlled by ambient acetaldehyde concentrations, stomatal conductance, and the acetaldehyde compensation point.

  2. Terahertz Spectroscopy of Deuterated Acetaldehyde: CH_2DCHO

    Margulès, L.; Motiyenko, R. A.; Coudert, L. H.; Guillemin, J.-C.

    2014-06-01

    This study follows our recent investigations about deuterated methyl-top species of complex organic molecules: methanol, methyl formate, In particular these works led the first ISM detection of HCOOCH_2D and CH_2DOCH_3. Acetaldehyde is not very abundant in the ISM, but this is a very interesting case from the spectroscopic point of view as it is an intermediate case between methyl formate and methanol. In the normal species of acetaldehyde, the barrier to internal rotation which is close to the value in methyl formate: 373 cm-1. However, the value of the Coriolis coupling constant ρ is 0.33 in acetaldehyde which is a much larger value than in methyl formate, 0.08, meaning that the coupling between the torsion and the overall rotation is more important. The sample was not a commercial one and half of its amount is the normal species which leads to a more difficult line assignment. The spectra were recorded in Lille between 75 and 950 GHz with a solid-state submillimeter-wave spectrometer. The starting point of the analysis was the centimeter-wave measurements carried out for the sym and asym- conformers. A comparison between the approach developed for deuterated methyl formate (HCOOCH_2D), based on the water dimer formalism, and that designed recently for deuterated methanola (CH_2DOH) will be presented. This work is supported by the CNES and the Action sur Projets de l'INSU, PCMI. Coudert, L. H.; et al. J. Chem. Phys., 140, (2014) 64307 Coudert, L. H.; et al. ApJ, 779, (2013) 119 Richard, C.; et al. A&A, 552, (2013) A117 Smirnov, I. A.; et al. J. Mol. Spectrosc., 295 (2014) 44 Ilyushin, V.; et al. J. Mol. Spectrosc., 255 (2009) 32 Turner, P. H.; and Cox, A. P. Chem. Phys. Lett., 42, (1976) 84 Turner, P. H.; Cox, A. P.; and Hardy, J. A. J.C.S. Farady Trans., 2, (1981) 1217

  3. Plant physiological and environmental controls over the exchange of acetaldehyde between forest canopies and the atmosphere

    K. Jardine

    2008-11-01

    Full Text Available We quantified fine scale sources and sinks of gas phase acetaldehyde in two forested ecosystems in the US. During the daytime, the upper canopy behaved as a net source while at lower heights, reduced emission rates or net uptake were observed. At night, uptake generally predominated throughout the canopies. Net ecosystem emission rates were inversely related to foliar density due to the extinction of light in the canopy and a respective decrease of the acetaldehyde compensation point. This is supported by branch level studies revealing much higher compensation points in the light than in the dark for poplar (Populus deltoides and holly oak (Quercus ilex implying a higher light/temperature sensitivity for acetaldehyde production relative to consumption. The view of stomata as the major pathway for acetaldehyde exchange is supported by strong linear correlations between branch transpiration rates and acetaldehyde exchange velocities for both species. In addition, natural abundance carbon isotope analysis of gas-phase acetaldehyde during poplar branch fumigation experiments revealed a significant kinetic isotope effect of 5.1±0.3‰ associated with the uptake of acetaldehyde. Similar experiments with dry dead poplar leaves showed no fractionation or uptake of acetaldehyde, confirming that this is only a property of living leaves. We suggest that acetaldehyde belongs to a potentially large list of plant metabolites where stomatal resistance can exert long term control over both emission and uptake rates due to the presence of both source(s and sink(s within the leaf which strongly buffer large changes in concentrations in the substomatal airspace due to changes in stomatal resistance. We conclude that the exchange of acetaldehyde between plant canopies and the atmosphere is fundamentally controlled by ambient acetaldehyde concentrations, stomatal resistance, and the compensation point which is a function of light/temperature.

  4. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Measurement methods for formaldehyde... Measurement methods for formaldehyde and acetaldehyde. (a) Formaldehyde and acetaldehyde will be measured by....140 of this chapter for formaldehyde analysis. Diluted exhaust sample volumes must be at least 15...

  5. Oxygen vacancy-assisted coupling and enolization of acetaldehyde on CeO2(111).

    Calaza, Florencia C; Xu, Ye; Mullins, David R; Overbury, Steven H

    2012-10-31

    The temperature-dependent adsorption and reaction of acetaldehyde (CH(3)CHO) on a fully oxidized and a highly reduced thin-film CeO(2)(111) surface have been investigated using a combination of reflection-absorption infrared spectroscopy (RAIRS) and periodic density functional theory (DFT+U) calculations. On the fully oxidized surface, acetaldehyde adsorbs weakly through its carbonyl O interacting with a lattice Ce(4+) cation in the η(1)-O configuration. This state desorbs at 210 K without reaction. On the highly reduced surface, new vibrational signatures appear below 220 K. They are identified by RAIRS and DFT as a dimer state formed from the coupling of the carbonyl O and the acyl C of two acetaldehyde molecules. This dimer state remains up to 400 K before decomposing to produce another distinct set of vibrational signatures, which are identified as the enolate form of acetaldehyde (CH(2)CHO¯). Furthermore, the calculated activation barriers for the coupling of acetaldehyde, the decomposition of the dimer state, and the recombinative desorption of enolate and H as acetaldehyde are in good agreement with previously reported TPD results for acetaldehyde adsorbed on reduced CeO(2)(111) [Chen et al. J. Phys. Chem. C 2011, 115, 3385]. The present findings demonstrate that surface oxygen vacancies alter the reactivity of the CeO(2)(111) surface and play a crucial role in stabilizing and activating acetaldehyde for coupling reactions. PMID:23020248

  6. Acetaldehyde alters MAP kinase signalling and epigenetic histone modifications in hepatocytes.

    Shukla, Shivendra D; Lee, Youn Ju; Park, Pil-hoon; Aroor, Annayya R

    2007-01-01

    Although both oxidative and non-oxidative metabolites of ethanol are involved in generating ethanol matabolic stress (Emess), the oxidative metabolite acetaldehyde plays a critical role in the cellular actions of ethanol. We have investigated the effects of acetaldehyde on p42/44 MAP kinase, p46/p54 c-jun N-terminal kinase (JNK1/JNK2) and p38 MAP kinase in hepatocytes. Acetaldehyde caused temporal activation of p42/44 MAPK followed by JNK, but the activation of the p42/44 MAPK was not a prerequisite for the JNK activation. Activation ofJNK1 by acetaldehyde was greater than JNK2. Ethanol and acetaldehyde activatedJNK have opposing roles; ethanol-induced JNK activation increased apoptosis whereas that by acetaldehyde decreased apoptosis. Acetaldehyde also caused histone H3 acetylation at Lys9 and phosphorylation of histone H3 at Serl0 and 28, the latter being dependent on p38 MAP kinase. Phosphorylation at Ser28 was higher than at Serl0. Thus acetaldehyde distinctively alters MAP kinase signalling and histone modifications, processes involved in transcriptional activation. PMID:17590997

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

    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

  8. EFFECT OF SOME TECHNOLOGICAL FACTORS ON THE CONTENT OF ACETALDEHYDE IN BEER

    Gunka Jonkova

    2010-10-01

    Full Text Available The purpose of this work was to examine the influence of the temperature, the pitching rate of yeast and wort composition (Free Amino Nitrogen on the content of acetaldehyde in beer. It is known, that higher fermentation temperatures stimulate the formation of acetaldehyde, as well as the higher rate of acetaldehyde reduction, leading to lower concentrations in the final beer. Beer produced with increased pitching rate of yeast (26 and 35 × 10[sup]6[/sup] cells•mL[sup]-1[/sup], contains lower quantities of acetaldehyde as compared to the control beer. Lower content of α-amino nitrogen in result of substitution of 5 to 10�0of the malt with rice, sugar or a combination of both does not lead to considerable differences in the acetaldehyde concentration in beer.

  9. Acetaldehyde and parkinsonism: role of CYP450 2E1

    Giovanni Umberto Corsini

    2013-06-01

    We have indicated that acetaldehyde is able to enhance the parkinsonism induced in mice by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a neurotoxin able to damage the nigrostriatal dopaminergic pathway. Similarly diethyldithiocarbamate, the main metabolite of disulfiram, a drug widely used to control alcoholism, diallylsulfide and phenylisothiocyanate also markedly enhance the toxin-related parkinsonism. All these compounds are substrate/inhibitors of CYP450 2E1 isozyme. The presence of CYP 2E1 has been detected in the dopamine neurons of rodent Substantia Nigra, but a precise function of the enzyme has not been elucidated yet. By treating CYP 2E1 knockout mice with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, the Substantia Nigra induced lesion was significantly reduced when compared with the lesion observed in wild-type animals. Several in vivo and in vitro studies led to the conclusion that CYP 2E1 may enhance the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in mice by increasing free radical production inside the dopaminergic neurons. Acetaldehyde is a good substrate for CYP 2E1 enzyme as the other substrate-inhibitors and by this way may facilitate the susceptibility of dopaminergic neurons to toxic events. The literature suggests that ethanol and/or disulfiram may be responsible for toxic parkinsonism in human and it indicates that basal ganglia are the major targets of disulfiram toxicity. A very recent study reports that there are a decreased methylation of the CYP 2E1 gene and increased expression of CYP 2E1 mRNA in Parkinson’s Disease patient brains. This study suggests that epigenetic variants of this cytochrome contribute to the susceptibility, thus confirming multiples lines of evidence which indicate a link between environmental toxins and Parkinson’s Disease.

  10. The role of acetaldehyde in pregnancy outcome after prenatal alcohol exposure.

    Hard, M L; Einarson, T R; Koren, G

    2001-08-01

    It is not known why some heavy-drinking women give birth to children with alcohol-related birth defects (ARBD) whereas others do not. The objective of this study was to determine whether the frequency of elevated maternal blood acetaldehyde levels among alcoholics is in the range of ARBD among alcoholic women. MEDLINE was searched from 1980 to 2000 using the key words acetaldehyde, pharmacokinetics, and alcoholism for controlled trials reporting blood or breath acetaldehyde levels in alcoholics and nonalcoholics. Separately, using the key words fetal alcohol syndrome, epidemiology, prevalence, incidence, and frequency, articles were identified reporting ARBD incidences among the offspring of heavy drinkers. Of 23 articles reporting acetaldehyde levels in alcoholics, four met the inclusion criteria. Forty-three studies reported on the rate of ARBD in heavy drinkers, and 14 were accepted. Thirty-four percent of heavy drinkers had a child with ARBD, and 43% of chronic alcoholics had high acetaldehyde levels. The similar frequencies of high acetaldehyde levels among alcoholics and the rates of ARBD among alcoholic women provide epidemiologic support to the hypothesis that acetaldehyde may play a major role in the cause of ARBD. PMID:11477328

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

    Halinska, A.; Frenkel, C. (Rutgers, The State Univ. of New Jersey, New Brunswick (United States))

    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.

  12. EFFECT OF SOME TECHNOLOGICAL FACTORS ON THE CONTENT OF ACETALDEHYDE IN BEER

    Gunka Jonkova; Nevjana Petkova

    2010-01-01

    The purpose of this work was to examine the influence of the temperature, the pitching rate of yeast and wort composition (Free Amino Nitrogen) on the content of acetaldehyde in beer. It is known, that higher fermentation temperatures stimulate the formation of acetaldehyde, as well as the higher rate of acetaldehyde reduction, leading to lower concentrations in the final beer. Beer produced with increased pitching rate of yeast (26 and 35 × 10[sup]6[/sup] cells•mL[sup]-1[/sup]), contains low...

  13. Comparison of Ethanol and Acetaldehyde Toxicity in Rat Astrocytes in Primary Culture

    Šarc, Lucija; Lipnik-Štangelj, Metoda

    2009-01-01

    This study compared the effects of toxicity of ethanol and its first metabolite acetaldehyde in rat astrocytes through cell viability and cell proliferation. The cells were treated with different concentrations of ethanol in the presence or absence of a catalase inhibitor 2-amino-1,2,4 triazole (AMT) or with different concentrations of acetaldehyde. Cell viability was assessed using the trypan blue test. Cell proliferation was assessed after 24 hours and after seven days of exposure to either...

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

    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

  15. Seasonal and diurnal variation in formaldehyde and acetaldehyde concentrations along a highway in Eastern Finland

    Viskari, E.-L. [University of Kuopio (Finland). Dept. of Ecology and Environmental Science; Vartiainen, M. [National Public Health Institute, Kuopio (Finland). Environmental Health, Air Research Laboratory; Pasanen, P. [University of Kuopio (Finland). Dept. of Environmental Science

    2000-07-01

    In this study the concentrations of the most important carbonyl compounds, formaldehyde and acetaldehyde, are measured in a highway environment in spring, summer and winter. Measurements were carried out in May, July and January along a two-lane highway, with daily traffic density 27 500 vehicles. Four sampling points were selected: (1) one from east and (2) west sides of the highway, (3) one at the central reservation of the highway and (4) one background site. The formaldehyde and acetaldehyde concentrations measured at both sides of a two-lane highway and at the central reservation suggest that the motor vehicle emissions are the source of these compounds throughout the year. The concentrations were, however, significantly lower at the roadsides than at the central reservation, especially in July. This could indicate rapid dilution of these compounds in the air. It is also possible that the vegetation along the roadside in summer may play a role as a sink or as a biogenic source for these compounds. The concentrations measured along the roadside in this study are comparable to those measured in polluted urban areas. The diurnal variation showed significant decrease of formaldehyde and acetaldehyde concentrations in the night indicating a decrease in primary source, i.e. traffic emissions. The seasonal variation was great as well, concentrations being lower in winter time, indicating lower secondary production of aldehydes. The formaldehyde and acetaldehyde effects on plants remains to be studied, since the formaldehyde and acetaldehyde pose a noteworthy risk to the vegetation exposed. (author)

  16. Chemistry of di-and tetrahydropyrans. Communication 4. Reaction of 4-methylenetetrahydropyran with formaldehyde and acetaldehyde

    The thermal condensation of formaldehyde with 4-methylenetetrahydropyran at 1800C leads to 4-(2'-hydroxyethyl)-5,6-dihydropyran, while an acid-catalyzed condensation leads to 1,3,9-trioxaspiro[5,5]undecane. 2,4-Dimethyl-1,3,9-trioxaspiro[5.5]undecane and 5-hydroxy-1,3-dimethyl-2,8-dioxabicyclo[4.4.0]decane were synthesized by the reaction of 4-methylenetetrahydropyran with acetaldehyde. In the cocondensation of formaldehyde and acetaldehyde with 4-methylenetetrahydropyran under acidic catalysis conditions, not only the expected 2-methyl-1,3,9-trioxaspiro[5.5]undecane, but also 5-hydroxy-1-methyl-2,8-dioxabicyclo[4.4.0]decane is formed in a comparable yield as well as products of a reaction of the olefin with acetaldehyde

  17. Artisanal alcohol production in Mayan Guatemala: Chemical safety evaluation with special regard to acetaldehyde contamination

    Kanteres, Fotis [Centre for Addiction and Mental Health (CAMH), 33 Russell Street, ARF 2035, Toronto, ON, Canada, M5S 2 S1 (Canada); Rehm, Juergen [Centre for Addiction and Mental Health (CAMH), 33 Russell Street, ARF 2035, Toronto, ON, Canada, M5S 2 S1 (Canada); Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, ON, Canada, M5T 3 M7 (Canada); Institute for Clinical Psychology and Psychotherapy, TU Dresden, Chemnitzer Strasse 46, D-01187 Dresden (Germany); Lachenmeier, Dirk W., E-mail: Lachenmeier@web.de [Chemisches und Veterinaeruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, D-76187 Karlsruhe (Germany)

    2009-11-01

    There is a lack of knowledge regarding the composition, production, distribution, and consumption of artisanal alcohol, particularly in the developing world. In Nahuala, an indigenous Mayan municipality located in highland Guatemala, heavy alcohol consumption appears to have had a significant negative impact on health, a major role in cases of violence and domestic abuse, and a link to street habitation. Cuxa, an artisanally, as well as commercially produced sugarcane alcohol, is widely consumed by heavy drinkers in this community. Cuxa samples from all distribution points in the community were obtained and chemically analyzed for health-relevant constituents and contaminants including methanol, acetaldehyde, higher alcohols, and metals. From those, only acetaldehyde was confirmed to be present in unusually high levels (up to 126 g/hl of pure alcohol), particularly in samples that were produced clandestinely. Acetaldehyde has been evaluated as 'possibly carcinogenic' and has also been identified as having significant human exposure in a recent risk assessment. This study explores the reasons for the elevated levels of acetaldehyde, through both sampling and analyses of raw and intermediary products of cuxa production, as well as interviews from producers of the clandestine alcohol. For further insight, we experimentally produced this alcohol in our laboratory, based on the directions provided by the producers, as well as materials from the town itself. Based on these data, the origin of the acetaldehyde contamination appears to be due to chemical changes induced during processing, with the major causative factors consisting of poor hygiene, aerobic working conditions, and inadequate yeast strains, compounded by flawed distillation methodology that neglects separation of the first fractions of the distillate. These results indicate a preventable public health concern for consumers, which can be overcome through education about good manufacturing practices

  18. Artisanal alcohol production in Mayan Guatemala: Chemical safety evaluation with special regard to acetaldehyde contamination

    There is a lack of knowledge regarding the composition, production, distribution, and consumption of artisanal alcohol, particularly in the developing world. In Nahuala, an indigenous Mayan municipality located in highland Guatemala, heavy alcohol consumption appears to have had a significant negative impact on health, a major role in cases of violence and domestic abuse, and a link to street habitation. Cuxa, an artisanally, as well as commercially produced sugarcane alcohol, is widely consumed by heavy drinkers in this community. Cuxa samples from all distribution points in the community were obtained and chemically analyzed for health-relevant constituents and contaminants including methanol, acetaldehyde, higher alcohols, and metals. From those, only acetaldehyde was confirmed to be present in unusually high levels (up to 126 g/hl of pure alcohol), particularly in samples that were produced clandestinely. Acetaldehyde has been evaluated as 'possibly carcinogenic' and has also been identified as having significant human exposure in a recent risk assessment. This study explores the reasons for the elevated levels of acetaldehyde, through both sampling and analyses of raw and intermediary products of cuxa production, as well as interviews from producers of the clandestine alcohol. For further insight, we experimentally produced this alcohol in our laboratory, based on the directions provided by the producers, as well as materials from the town itself. Based on these data, the origin of the acetaldehyde contamination appears to be due to chemical changes induced during processing, with the major causative factors consisting of poor hygiene, aerobic working conditions, and inadequate yeast strains, compounded by flawed distillation methodology that neglects separation of the first fractions of the distillate. These results indicate a preventable public health concern for consumers, which can be overcome through education about good manufacturing practices, as well

  19. Generation of acetyl free radicals by radiolysis: comparison of free radicals generated from acetaldehyde and ethylene-glycol

    The optical absorption spectra of the intermediates obtained by pulse radiolysis of N2O-saturated solutions of acetaldehyde or ethylene-glycol and the kinetics of their decays have been investigated. Results suggest that the OH· radical reactions with acetaldehyde or ethylene-glycol produce acetyl and formylmethyl radicals. Besides, these radicals are shown to reduce ferricytochrome c

  20. Adsorption of Chromium(VI from Aqueous Solutions by Coffee Polyphenol-Formaldehyde/Acetaldehyde Resins

    Khudbudin Mulani

    2013-01-01

    Full Text Available Removal of chromium(VI from wastewater is essential as it is toxic. Thus, removal of chromium(VI was performed using coffee polyphenol-formaldehyde/acetaldehyde resins as adsorbents. Adsorbent resins were prepared by condensation of decaffeinated coffee powder with formaldehyde/acetaldehyde and used for the removal of Cr(VI ions from aqueous solutions. A simple and sensitive solid phase extraction procedure was applied for the determination of chromium at trace levels by spectroscopic method using 1,5-diphenylcarbazide reagent. The adsorption of Cr(VI on the coffee polyphenol-formaldehyde/acetaldehyde resins was monitored by FTIR and EDX analysis. The metal adsorption parameters such as contact time, pH, Cr(VI ion concentration, and adsorbent dose were investigated. For Cr(VI, the maximum adsorption capacity of coffee polyphenol-formaldehyde resins was 98% at pH 2. The experimental results showed that Cr(VI bound strongly with coffee polyphenol-formaldehyde/acetaldehyde resins and utilization of resins could be improved greatly by reuse.

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

    Laura Font

    2013-07-01

    Full Text Available Significant evidence implicates the endogenous opioid system (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. 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. 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.

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

    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. PMID:23296804

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

    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.

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

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

    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

  6. Selective catalytic reduction of nitric oxide with acetaldehyde over NaY zeolite catalyst in lean exhaust feed

    Steady-state selective catalytic reduction (SCR) of nitric oxide (NO) was investigated under simulated lean-burn conditions using acetaldehyde (CH3CHO) as the reductant. This work describes the influence of catalyst space velocity and the impact of nitric oxide, acetaldehyde, oxygen, sulfur dioxide, and water on NOx reduction activity over NaY zeolite catalyst. Results indicate that with sufficient catalyst volume 90% NOx conversion can be achieved at temperatures relevant to light-duty diesel exhaust (150-350C). Nitric oxide and acetaldehyde react to form N2, HCN, and CO2. Oxygen is necessary in the exhaust feed stream to oxidize NO to NO2 over the catalyst prior to reduction, and water is required to prevent catalyst deactivation. Under conditions of excess acetaldehyde (C1:N>6:1) and low temperature (x conversion is apparently very high; however, the NOx conversion steadily declines with time due to catalytic oxidation of some of the stored (adsorbed) NO to NO2, which can have a significant impact on steady-state NOx conversion. With 250ppm NO in the exhaust feed stream, maximum NOx conversion at 200C can be achieved with =400ppm of acetaldehyde, with higher acetaldehyde concentrations resulting in production of acetic acid and breakthrough of NO2 causing lower NOx conversion levels. Less acetaldehyde is necessary at lower NO concentrations, while more acetaldehyde is required at higher temperatures. Sulfur in the exhaust feed stream as SO2 can cause slow deactivation of the catalyst by poisoning the adsorption and subsequent reaction of nitric oxide and acetaldehyde, particularly at low temperature

  7. Ambient temperature operated acetaldehyde vapour detection of spray deposited cobalt doped zinc oxide thin film.

    Shalini, S; Balamurugan, D

    2016-03-15

    Undoped and Co-doped ZnO thin films were prepared by a home built spray pyrolysis method. X-ray diffraction results indicate that both undoped and Co-doped ZnO have a polycrystalline nature and a preferential orientation peak in the (002) plane. From a field-emission scanning electron micrographs of annealed films, a uniform distribution of nanoparticles along with nanorods was observed. UV-Visible measurement indicated that all the films are transparent in the visible region. The electrical resistance was also reported. The acetaldehyde sensing behaviour of the prepared undoped and Co-doped ZnO thin films was studied using the chemi-resistive method at ambient temperature (∼30 °C). In the presence of 10 ppm of acetaldehyde vapour, the Co-doped ZnO thin films showed good sensing response of 74% with fast response and recovery time of 3 s and 110 s respectively. PMID:26748067

  8. ALDH2 Genotype Has No Effect on Salivary Acetaldehyde without the Presence of Ethanol in the Systemic Circulation

    Helminen, Andreas; Väkeväinen, Satu; Salaspuro, Mikko

    2013-01-01

    Background Acetaldehyde associated with alcoholic beverages was recently classified as carcinogenic (Group 1) to humans based on uniform epidemiological and biochemical evidence. ALDH2 (aldehyde dehydrogenase 2) deficient alcohol consumers are exposed to high concentrations of salivary acetaldehyde and have an increased risk of upper digestive tract cancer. However, this interaction is not seen among ALDH2 deficient non-drinkers or rare drinkers, regardless of their smoking status or consumpt...

  9. Polyamines stimulate the formation of mutagenic 1,N 2-propanodeoxyguanosine adducts from acetaldehyde

    Theruvathu, Jacob A.; Jaruga, Pawel; Nath, Raghu G.; Dizdaroglu, Miral; Brooks, P. J.

    2005-01-01

    Alcoholic beverage consumption is associated with an increased risk of upper gastrointestinal cancer. Acetaldehyde (AA), the first metabolite of ethanol, is a suspected human carcinogen, but the molecular mechanisms underlying AA carcinogenicity are unclear. In this work, we tested the hypothesis that polyamines could facilitate the formation of mutagenic α-methyl-γ-hydroxy-1,N 2-propano-2′-deoxyguanosine (Cr-PdG) adducts from biologically relevant AA concentrations. We found that Cr-PdG addu...

  10. (3s←n) REMPI of jet-cooled acetaldehyde using two laser beams

    Philis, J. G.; Kosmidis, C.

    2001-05-01

    The 3s←n Rydberg transition of acetaldehyde has been studied by a two-color experiment (545 and 272.5 nm light) by means of a TOF mass spectrometer. The recorded spectra are in close resemblance to the known one-color (2R+1) MPI spectra (364 nm). Nevertheless, the observed mass spectra are different. These differences are discussed in detail. Moreover, two-photon resonances of atomic carbon have been detected, indicating complete dissociation of some neutral fragments.

  11. Determination of free acetaldehyde in blood as the dinitrophenylhydrazone derivative by high-performance liquid chromatography.

    Lucas, D; Ménez, J F; Berthou, F; Pennec, Y; Floch, H H

    1986-10-31

    A simple and sensitive method is proposed for the measurement of acetaldehyde in human blood. Venous blood samples were collected in EDTA Vacutainer tubes, and treated immediately with 0.6 M ice-cold perchloric acid in saline. After centrifugation at 4 degrees C, the supernatants were treated with dinitrophenylhydrazine reagent. After addition of the internal standard (crotonaldehyde dinitrophenylhydrazone) and 3 M sodium acetate, the derivatives were extracted and analysed by high-performance liquid chromatography (HPLC) using an Ultrasphere ODS column. The compounds were separated using acetonitrile--water as the mobile phase and detected at 356 nm. A blank determination was carried out for each analysis and subtracted from the results. The specificity of the method was tested by UV and mass spectrometry and the purity of the derivatives by capillary gas chromatography. The recovery of blood acetaldehyde was 98%. Interference from ethanol was minimized by using the tripotassium salt of EDTA as an anticoagulant. The sensitivity of the method can be increased dramatically using microbore HPLC. The level of acetaldehyde was found to be 0.41 +/- 0.13 microM (mean +/- S.D.) for eight fasting controls and 0.91 +/- 0.73 microM for fourteen alcoholics (p less than 0.05). At 30 min after oral administration of ethanol (0.8 g/kg), the ethanol levels were 16.3 +/- 2.8 and 17.7 +/- 2.5 mM and the acetaldehyde levels were 1.67 +/- 0.35 and 3.13 +/- 2.43 microM (p less than 0.05) for the controls and alcoholics, respectively. PMID:3782415

  12. Photodissociation of acetaldehyde as a second example of the roaming mechanism

    Houston, P. L.; Kable, S. H.

    2006-01-01

    Product state distributions of the CO produced in the 308-nm photolysis of acetaldehyde show clear evidence of two dissociation mechanisms. One is attributed to the conventional transition state mechanism predicted by theory, with high rotational and translational energy of the CO and a pronounced v⊥J vector correlation. However, as much as 15% of the reaction flux proceeds via another pathway that produces low CO rotational and translational energy, very high CH4 internal energy, and no corr...

  13. Acetaldehyde Oxime, A Product Formed during the In Vivo Nitrate Reductase Assay of Soybean Leaves.

    Mulvaney, C S; Hageman, R H

    1984-09-01

    Evolution of nitrogen oxides (NO((x)), primarily as nitric oxide) from soybean (Glycine max [L.] Merr.) leaves during purged in vivo nitrate reductase assays had been reported; however, these reports were based on a method that had been used for determination of NO((x)) in air. This method also detects other N compounds. Preliminary work led us to doubt that the evolved N was nitric oxide. Studies were undertaken to identify the N compound evolved from the in vivo assay that had been reported as NO((x)). Material for identification was obtained by cryogenic trapping and fractional distillation, and by chemical trapping procedures. Mass spectrometry, ultraviolet spectroscopy, and (15)N-labeled nitrate were used to identify the compounds evolved and to determine whether these compounds were derived from nitrate. Acetaldehyde oxime was identified as the predominant N compound evolved and this compound is readily detected by the method for NO((x)) determination. Substantial quantities of acetaldehyde oxime (16.2 micromoles per gram fresh weight per hour) were evolved during the in vivo assay. Small amounts of nitrous oxide (0.63 micrograms N per gram fresh weight per hour) were evolved, but this compound is not detected as NO((x)). Acetaldehyde oxime and nitrous oxide were both produced as a result of nitrate ((15)NO(3) (-)) reduction during the assay. PMID:16663781

  14. Acetaldehyde Oxime, A Product Formed during the In Vivo Nitrate Reductase Assay of Soybean Leaves 1

    Mulvaney, Charlene S.; Hageman, Richard H.

    1984-01-01

    Evolution of nitrogen oxides (NO(x), primarily as nitric oxide) from soybean (Glycine max [L.] Merr.) leaves during purged in vivo nitrate reductase assays had been reported; however, these reports were based on a method that had been used for determination of NO(x) in air. This method also detects other N compounds. Preliminary work led us to doubt that the evolved N was nitric oxide. Studies were undertaken to identify the N compound evolved from the in vivo assay that had been reported as NO(x). Material for identification was obtained by cryogenic trapping and fractional distillation, and by chemical trapping procedures. Mass spectrometry, ultraviolet spectroscopy, and 15N-labeled nitrate were used to identify the compounds evolved and to determine whether these compounds were derived from nitrate. Acetaldehyde oxime was identified as the predominant N compound evolved and this compound is readily detected by the method for NO(x) determination. Substantial quantities of acetaldehyde oxime (16.2 micromoles per gram fresh weight per hour) were evolved during the in vivo assay. Small amounts of nitrous oxide (0.63 micrograms N per gram fresh weight per hour) were evolved, but this compound is not detected as NO(x). Acetaldehyde oxime and nitrous oxide were both produced as a result of nitrate (15NO3−) reduction during the assay. PMID:16663781

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

    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. PMID:24518311

  16. Evaluating acetaldehyde synthesis from L-14C(U)] threonine by Streptococcus thermophilus and Lactobacillus bulgaricus

    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 420C, 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 420C 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 480C was 89% lower than that of cells grown at 300C. Cell extracts from S. thermophilus MS1 possessed higher threonine aldolase activity than did those from L. bulgaricus MR1. Increased assay temperature from 30 to 420C increased threonine aldolase activity in S. thermophilus MS1

  17. Vertical fluxes and atmospheric cycling of methanol, acetaldehyde, and acetone in a coastal environment

    M. Yang

    2013-03-01

    Full Text Available We present here vertical fluxes of methanol, acetaldehyde, and acetone measured directly with eddy covariance (EC during March to July 2012 near the southwest coast of the UK. The performance of the proton-transfer reaction mass spectrometer (PTR-MS for flux measurement is characterized, with additional considerations given to the homogeneity and stationarity assumptions required by EC. Concentrations and fluxes of these compounds vary significantly with time of day and wind direction. Higher values of acetaldehyde and acetone are usually observed in the daytime and from the direction of a forested park, most likely due to light-driven emissions from terrestrial plants. Methanol concentration and flux do not demonstrate clear diel variability, suggesting sources in addition to plants. We estimate air–sea exchange and photochemical rates of these compounds, which are compared to measured vertical fluxes. For acetaldehyde, the mean (1σ concentration of 0.13 (0.02 ppb at night may be maintained by oceanic emission, while photochemical destruction outpaces production during the day. Air-sea exchange and photochemistry are probably net sinks of methanol and acetone in this region. Their nighttime concentrations of 0.46 (0.20 and 0.39 (0.08 ppb appear to be affected more by terrestrial emissions and long distance transport, respectively.

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

    A. C. Lewis

    2005-01-01

    Full Text Available 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.

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

    A. C. Lewis

    2005-03-01

    Full Text Available 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.

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

    Monakhova Yulia B; Lachenmeier Dirk W

    2011-01-01

    Abstract 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 b...

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

    Monakhova Yulia B

    2011-01-01

    Full Text Available Abstract 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

  2. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    Tingting Yan; Yan Zhao; Xia Zhang; Xiaotong Lin

    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 ...

  3. Adsorption and Photocatalytic Kinetics of Visible-Light Response N-Doped TiO2 Nanocatalyst for Indoor Acetaldehyde Removal under Dark and Light Conditions

    Yu-Hao Lin

    2016-01-01

    Full Text Available Understanding the removal nature of the indoor volatile organic compounds under realistic environment conditions would give clear guidance for the development of air purification devices. The study investigated the removal of indoor acetaldehyde using visible-light-responsive N-doped TiO2 (N-TiO2 photocatalyst under visible-light irradiation (light and in the absence of light (dark. The adsorption kinetics of acetaldehyde onto N-TiO2 followed a pseudo-second-order model. The magnitude of acetaldehyde adsorption is proportional to temperature, and the results were fitted to the Langmuir isotherm model. Moreover, the effect of initial acetaldehyde concentration and visible-light intensity on the photooxidation of acetaldehyde was well described by the Langmuir-Hinshelwood model. Results show that the mesoporous N-TiO2 catalyst had a high ability to absorb acetaldehyde in the dark condition, and then acetaldehyde was subsequently photooxidized under visible-light irradiation. The adsorption capacity was found to increase with decreasing temperature. The negative value of ΔG° and the positive value of ΔS° indicate that the adsorption of acetaldehyde onto N-TiO2 was a spontaneous process. Finally, a reaction scheme for removal process of indoor acetaldehyde by N-TiO2 was proposed.

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

    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

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

    Mann, Amanda K [ORNL; Wu, Zili [ORNL; Calaza, Florencia [Max Planck Society, Fritz Haber Institute; Overbury, Steven {Steve} H [ORNL

    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.

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

    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 (ADHES77). Interestingly, the ADHES77 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 (NH4)2SO4 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. PMID:26216639

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

    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.

  8. Acetaldehyde reinforcement and motor reactivity in newborns with or without a prenatal history of alcohol exposure

    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....

  9. Acetaldehyde reinforcement and motor reactivity in newborns with or without a prenatal history of alcohol exposure

    Samanta Mabel March; Spear, Norman E.

    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...

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

    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

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

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

    2014-01-01

    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 (CH$_3$CHO) emission towards the chemically rich protostellar shock L1157-B1, obtained at 2 mm with the IRAM Plateau de Bure interferometer. Six blueshifted CH$_3$CHO lines w...

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

    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

  13. Interaction of yeasts with the products resulting from the condensation reaction between (+)-catechin and acetaldehyde.

    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

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

    Enrique-Romero, Joan; Ceccarelli, Cecilia; Balucani, Nadia

    2016-01-01

    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 a...

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

    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.

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

    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. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways.

    Yan, Tingting; Zhao, Yan; Zhang, Xia; Lin, Xiaotong

    2016-03-01

    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

  18. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    Tingting Yan

    2016-03-01

    Full Text Available 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.

  19. Thz Spectroscopy of 13C Isotopic Species of a "weed": Acetaldehyde

    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

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

    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.

  1. Minimising the Effects of Isobaric Product Ions in SIFT-MS Quantification of Acetaldehyde, Dimethyl Sulphide and Carbon Dioxide

    Smith, D.; Chippendale, T. W. E.; Španěl, Patrik

    2013-01-01

    Roč. 9, č. 4 (2013), s. 550-557. ISSN 1573-4110 Institutional support: RVO:61388955 Keywords : selected ion flow tube mass spectrometry * SIFT-MS * acetaldehyde Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.194, year: 2013

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

    Bertheussen, Erlend; Verdaguer Casadevall, Arnau; Ravasio, Davide;

    2016-01-01

    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 mino...

  3. Kinetic analysis on photocatalytic degradation of gaseous acetaldehyde, ammonia and hydrogen sulfide on nanosized porous TiO2 films

    Iis Sopyan

    2007-01-01

    Full Text Available The characteristics of the UV illumination-assisted degradation of gaseous acetaldehyde, hydrogen sulfide, and ammonia on highly active nanostructured-anatase and rutile films were investigated. It was found that the anatase film showed a higher photocatalytic activity than the counterpart did, however, the magnitude of difference in the photocatalytic activity of both films decreased in the order ammonia>acetaldehyde>hydrogen sulfide. To elucidate the reasons for the observation, the adsorption characteristics and the kinetics of photocatalytic degradation of the three reactants on both films were analyzed. The adsorption analysis examined using a simple Langmuir isotherm, showed that adsorbability on both films decreased in the order ammonia>acetaldehyde>hydrogen sulfide, which can be explained in terms of the decreasing electron-donor capacity. Acetaldehyde and ammonia adsorbed more strongly and with higher coverage on anatase film (1.2 and 5.6 molecules/nm2, respectively than on rutile (0.6 and 4.7 molecules/nm2, respectively. Conversely, hydrogen sulfide molecules adsorbed more strongly on rutile film (0.7 molecules/nm2 than on anatase (0.4 molecules/nm2. Exposure to UV light illumination brought about the photocatalytic oxidation of the three gases in contact with both TiO2 films, and the decrease in concentration were measured, and their kinetics are analyzed in terms of the Langmuir–Hinshelwood kinetic model. From the kinetic analysis, it was found that the anatase film showed the photocatalytic activities that were factors of ~8 and ~5 higher than the rutile film for the degradation of gaseous ammonia and acetaldehyde, respectively. However, the activity was only a factor of ~1.5 higher for the photodegradation of hydrogen sulfide. These observations are systematically explained by the charge separation efficiency and the adsorption characteristics of each catalyst as well as by the physical and electrochemical properties of each

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

    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 (Ppectinase 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

  5. Direct measurement of Criegee intermediate (CH2OO) reactions with acetone, acetaldehyde, and hexafluoroacetone.

    Taatjes, Craig A; Welz, Oliver; Eskola, Arkke J; Savee, John D; Osborn, David L; Lee, Edmond P F; Dyke, John M; Mok, Daniel W K; Shallcross, Dudley E; Percival, Carl J

    2012-08-14

    Criegee biradicals, i.e., carbonyl oxides, are critical intermediates in ozonolysis and have been implicated in autoignition chemistry and other hydrocarbon oxidation systems, but until recently the direct measurement of their gas-phase kinetics has not been feasible. Indirect determinations of Criegee intermediate kinetics often rely on the introduction of a scavenger molecule into an ozonolysis system and analysis of the effects of the scavenger on yields of products associated with Criegee intermediate reactions. Carbonyl species, in particular hexafluoroacetone (CF(3)COCF(3)), have often been used as scavengers. In this work, the reactions of the simplest Criegee intermediate, CH(2)OO (formaldehyde oxide), with three carbonyl species have been measured by laser photolysis/tunable synchrotron photoionization mass spectrometry. Diiodomethane photolysis produces CH(2)I radicals, which react with O(2) to yield CH(2)OO + I. The formaldehyde oxide is reacted with a large excess of a carbonyl reactant and both the disappearance of CH(2)OO and the formation of reaction products are monitored. The rate coefficient for CH(2)OO + hexafluoroacetone is k(1) = (3.0 ± 0.3) × 10(-11) cm(3) molecule(-1) s(-1), supporting the use of hexafluoroacetone as a Criegee-intermediate scavenger. The reactions with acetaldehyde, k(2) = (9.5 ± 0.7) × 10(-13) cm(3) molecule(-1) s(-1), and with acetone, k(3) = (2.3 ± 0.3) × 10(-13) cm(3) molecule(-1) s(-1), are substantially slower. Secondary ozonides and products of ozonide isomerization are observed from the reactions of CH(2)OO with acetone and hexafluoroacetone. Their photoionization spectra are interpreted with the aid of quantum-chemical and Franck-Condon-factor calculations. No secondary ozonide was observable in the reaction of CH(2)OO with acetaldehyde, but acetic acid was identified as a product under the conditions used (4 Torr and 293 K). PMID:22481381

  6. Ethanol and acetaldehyde potentiate the clastogenicity of ultraviolet light, methol methanesulfonate, mitomycin C and bleomycin in Chinese hamster ovary cells

    Ethanol itself did not induce any apparent chromosome aberrations in Chinese hamster ovary cells. However, posttreatment with ethanol potentiated the chromosome aberrations induced by ultraviolet light (UV), methyl methanesulfonate (MMS), mitomycin C (MMC) or bleomycin (BLM). Chromatid exchanges were predominantly increased in cultures treated with UV, MMS or MMC and then with ethanol, whereas chromosome breaks and chromatid exchange were the major types of aberrations increased in the cultures treated with BLM and ethanol. Posttreatment with acetaldehyde, the major metabolite of ethanol, also potentiated the chromosome aberrations induced by UV, MMS, MMC or BLM. The main types of aberrations potentiated by posttreatment with acetaldehyde were similar to those by posttreatment with ethanol. (author). 32 refs.; 3 figs.; 2 tabs

  7. Alcohol and acetaldehyde in African fermented milk mursik – A possible etiological factor for high incidence of esophageal cancer in western Kenya

    Nieminen, Mikko T.; Novak-Frazer, Lily; Collins, Rebecca; Dawsey, Sonja P.; Dawsey, Sanford M.; Abnet, Christian C.; White, Russell E.; Freedman, Neal D.; Mwachiro, Michael; Bowyer, Paul; Salaspuro, Mikko; Rautemaa, Riina

    2012-01-01

    Background Esophageal cancer is unusually frequent in western Kenya, despite the low prevalence of classical risk factors such as heavy drinking and tobacco smoking. Among Kenyans consumption of fermented milk is an old tradition. Our hypothesis is that alcohol and acetaldehyde are produced during the fermentation process and that their carcinogenic potential contributes to the high incidence of esophageal cancer. Methods Eight samples of mursik milk starter cultures were collected from different Kalenjin families in the Rift Valley province, Western Kenya. A protocol provided by the families was used for milk fermentation. Ethanol and acetaldehyde levels were measured by gas chromatography. The microbial flora in starter cultures was identified by 16S and 18S sequencing. Results 7/8 starter cultures produced mutagenic (>100 µM) levels of acetaldehyde and 4/8 starter cultures produced >1000 µM of acetaldehyde. The highest alcohol levels (mean 79.4 mM) were detected in the four fermented milks with highest acetaldehyde production. The mean number of microbial species in the starter cultures was 5 (range 2–8). Yeasts were identified in all starter cultures (mean 1.5 species/milk) but their proportion of the total microbial count varied markedly (mean 35%, range 7–90%). A combination of yeast and lactobacilli, especially Candida krusei with Lactobacillus kefiriwith the exclusion of other species, seemed to correlate with higher acetaldehyde and ethanol levels. Conclusions Significant levels of ethanol and acetaldehyde were produced during mursik fermentation. Impact When ingested several times daily the repeated exposure to carcinogenic levels of acetaldehyde may contribute to esophageal carcinogenesis. PMID:23155139

  8. An improved biosensor for acetaldehyde determination using a bienzymatic strategy at poly(neutral red) modified carbon film electrodes

    Ghica, Mariana Emilia; Pauliukaite, Rasa; Marchand, Nicolas; Devic, Eric; Brett, Christopher M. A.

    2007-01-01

    Improved biosensors for acetaldehyde determination have been developed using a bienzymatic strategy, based on a mediator-modified carbon film electrode and co-immobilisation of NADH oxidase and aldehyde dehydrogenase. Modification of the carbon film electrode with poly(neutral red) mediator resulted in a sensitive, low-cost and reliable NADH detector. Immobilisation of the enzymes was performed using encapsulation in a sol-gel matrix or cross-linking with glutaraldehyde. The bienzymatic biose...

  9. Quantitative NMR spectroscopy of binary liquid mixtures (aldehyde + alcohol) Part I: Acetaldehyde + (methanol or ethanol or 1-propanol)

    Highlights: • Formation of hemiacetal/poly(oxymethylene) hemiacetals in liquid binary mixtures. • Acetaldehyde and a low molecular alcohol (methanol or ethanol or 1-propanol). • Quantitative 13C NMR spectroscopy at temperatures between (255 and 295) K. • Hemiacetals are the predominant species. • (Acetaldehyde + methanol (50 + 50)) at 255 K: hemiacetal (polymers) >80% (≈10%). -- Abstract: Aldehydes react with alcohols to hemiacetals and poly(oxymethylene) hemiacetals. The chemical reaction equilibria of such reactions, in particular in the liquid state, can have an essential influence on the thermodynamic properties and related phenomena like, for example, on the vapour + liquid phase equilibrium. Therefore, thermodynamic models that aim to describe quantitatively such phase equilibria have to consider the chemical reaction equilibrium in the coexisting phases. This is well known in the literature for systems such as, for example, formaldehyde and methanol. However, experimental information on the chemical reaction equilibria in mixtures with other aldehydes (than formaldehyde) and alcohols is extremely scarce. Therefore, quantitative NMR spectroscopy was used to investigate the chemical reaction equilibria in binary mixtures of acetaldehyde and a single alcohol (here either methanol, ethanol or 1-propanol) at temperatures between (255 and 295) K. The results reveal that the majority of the constituents of the mixture is present as hemiacetal and the first two poly(oxymethylene) hemiacetals: in an equimolar mixture of (acetaldehyde + methanol or ethanol or 1-propanol), between about 90% at T = 255 K and about 75% at 295 K. The mole-fraction based chemical reaction equilibrium constants for the formation of those species were determined and some derived properties are reported

  10. Effect of TBZ, acetaldehyde, citral and Thymus capitatus essential oil on 'Minneola' tangelo fruit decay

    Arras, Giovanni; Piga, Antonio; Agabbio, Mario Carlo Salvatore

    1996-01-01

    Thiabendazole (TBZ), citral, acetaldehyde (AA), and Thymus capitatus essential oil-were tested for their ability to control decay on 'Minneola' tangelo fruit sprayed with a conidial suspension of Penicillium digitatum, either alone, or in combination with a low dose (100 ppm) of TBZ. TBZ at 2000 ppm was used as the standard. Thyme oil, citral and AA, all at 100 ppm (v/v), were applied under reduced pressure (0.6 bar) and heated to complete vaporisation. Control treatments were per...

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

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

    2016-01-01

    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...... 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....

  12. Cost-effectiveness analysis to assess commercial TiO2 photocatalysts for acetaldehyde degradation in air

    Verbruggen, Sammy W.; Tytgat, Tom; Van Passel, Steven; Martens, Johan A; Lenaerts, Silvia

    2014-01-01

    In the commercialisation of photocatalytic air purifiers, the performance as well as the cost of the catalytic material plays an important role. Where most comparative studies only regard the photocatalytic activity as a decisive parameter, in this study both activity and cost are taken into account. Using a cost-effectiveness analysis, six different commercially available TiO2-based catalysts are evaluated in terms of their activities in photocatalytic degradation of acetaldehyde as a model ...

  13. Evaluating acetaldehyde synthesis from L-/sup 14/C(U)) threonine by Streptococcus thermophilus and Lactobacillus bulgaricus

    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.

  14. Atmospheric formaldehyde and acetaldehyde at the campus University of Hiroshima, Japan

    Sonia Naomi Nomi

    2010-09-01

    Full Text Available Ambient levels of formaldehyde (HCHO and acetaldehyde (CH3CHO were measured at Hiroshima (Japan during spring and summer of 2005. Measurements of O3, NOx, and SO2 were simultaneously conducted, in an attempt to identify temporal profiles and sources for these aldehydes. Atmospheric aldehydes were collected using C18 silica gel cartridges coated with an acidic solution of 2, 4-dinitrophenylhydrazine (2,4-DNPH and analyzed by high performance liquid chromatography with UV/VIS detection adjusted to 360 nm. Summer concentrations were higher than spring levels. FA concentrations during spring period ranged from 0.50 to 1.05 ppb and AA concentrations ranged from 0.17 to 1.31 ppb; during summer their concentrations ranged from 1.55 to 4.12 ppb and 0. 34 to 2.03 ppb. Average FA/AA in spring and summer were 3.09 and 3.72 suggesting biogenic emissions of aldehydes. The levels of FA and AA, their temporal variations, and their concentration ratio (FA/AA indicated that photochemical reactions contributed significantly to the formation of atmospheric aldehydes at the study site.

  15. Conversion of ethanol to acetaldehyde by human placental homogenates and villi in vitro

    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 μM [1-14C]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 μM [1-14C]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

  16. Recombinant human diamine oxidase activity is not inhibited by ethanol, acetaldehyde, disulfiram, diethyldithiocarbamate or cyanamide.

    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

  17. Insights into photodissociation dynamics of acetaldehyde from ab initio calculations and molecular dynamics simulations

    In the present paper we report a theoretical study on mechanistic photodissociation of acetaldehyde (CH3CHO). Stationary structures for H2 and CO eliminations in the ground state (S0) 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 CH3CHO (265 nm1 C-C bond fission following intersystem crossing from the S1 state is the predominant channel and the minor channel, the ground-state elimination to CH4+CO after internal conversion (IC) from S1 to S0, could not be excluded. With the photon energy increasing, another pathway of IC, achieved via an S1/S0 intersection point resulting from the S1 C-C bond fission, becomes accessible and increases the yield of CH4+CO.

  18. Dissociation of acetaldehyde in intense laser field: Coulomb explosion or field-assisted dissociation?

    Dissociation of acetaldehyde in moderate strong laser field of 1013-1014 W/cm2 was investigated. Singly charged parent ion CH3CHO+ and fragmental ions CH3+, CHO+, C2H4+, O+, CH2CHO+, and H+ were produced by 800 nm laser of 100 fs pulse duration and recorded by time-of-flight mass spectrometer. The CH3+ fragment further dissociated to CH2+, CH+, and C+ ions at higher intensity. Ab initio calculated results show that the singly-, doubly-, and triply charged parent ions are stable. So, the dissociation mechanism was not due to Coulomb explosion of multicharged ion. A field-assisted dissociation (FAD) theory, which assumes that only one bond undergoes dissociation while the rest of the molecular geometry stays unchanged, was employed to treat the dissociation dynamics. Accordingly, the dressed potential energy surfaces of the ground state for the parent and the fragment ions were calculated. Corresponding quasiclassical trajectory calculations show that the bond ruptures take place in the order of C-C, C-O, and C-H, agreeing with the observation. The observed angular dependence and charge distribution of the product ions can also be interpreted by the FAD theory

  19. Dissociation of acetaldehyde in intense laser field: Coulomb explosion or field-assisted dissociation?

    Elshakre, Mohamed E.; Gao, Lirong; Tang, Xiaoping; Wang, Sufan; Shu, Yafei; Kong, Fanao

    2003-09-01

    Dissociation of acetaldehyde in moderate strong laser field of 1013-1014W/cm2 was investigated. Singly charged parent ion CH3CHO+ and fragmental ions CH3+, CHO+, C2H4+, O+, CH2CHO+, and H+ were produced by 800 nm laser of 100 fs pulse duration and recorded by time-of-flight mass spectrometer. The CH3+ fragment further dissociated to CH2+, CH+, and C+ ions at higher intensity. Ab initio calculated results show that the singly-, doubly-, and triply charged parent ions are stable. So, the dissociation mechanism was not due to Coulomb explosion of multicharged ion. A field-assisted dissociation (FAD) theory, which assumes that only one bond undergoes dissociation while the rest of the molecular geometry stays unchanged, was employed to treat the dissociation dynamics. Accordingly, the dressed potential energy surfaces of the ground state for the parent and the fragment ions were calculated. Corresponding quasiclassical trajectory calculations show that the bond ruptures take place in the order of C-C, C-O, and C-H, agreeing with the observation. The observed angular dependence and charge distribution of the product ions can also be interpreted by the FAD theory.

  20. Spectroscopic analysis, AIM, NLO and VCD investigations of acetaldehyde thiosemicarbazone using quantum mechanical simulations

    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.

  1. Detecting ethanol and acetaldehyde by simple and ultrasensitive fluorimetric methods in compound foods.

    Zachut, M; Shapiro, F; Silanikove, N

    2016-06-15

    There is a need for simple, accurate, and rapid analysis of ethanol (Eth) and acetaldehyde (AA) in a wide variety of beverages and foods. A novel enzymatic assay coupled to formation of fluorescent chromophore is presented. Eth detection was further improved by adding semicarbazide to the reaction mixture, which interacts with AA and prevents its inhibitory effect on Eth oxidation. The limits of detection of Eth (0.5 mg/L) and AA (0.9 mg/L) are comparable with the performance of modern gas chromatography techniques. The repeatability of Eth and AA detection in various foods (9% on average) was lower than that with commercial kits (23%). The high sensitivity of the developed method enables detection of AA in common foods [e.g., bio-yogurt (12.2 mg/L), and the existence of endogenous Eth (1.8 mg/L) and AA (2.0 mg/L) in bacteria-free non-fermented bovine milk], which could not measured so far by enzymatic methods. PMID:26868576

  2. Non-Saccharomyces and Saccharomyces strains co-fermentation increases acetaldehyde accumulation: effect on anthocyanin-derived pigments in Tannat red wines.

    Medina, Karina; Boido, Eduardo; Fariña, Laura; Dellacassa, Eduardo; Carrau, Francisco

    2016-07-01

    During fermentation, Saccharomyces cerevisiae releases into the medium secondary metabolic products, such as acetaldehyde, able to react with anthocyanins, producing more stable derived pigments. However, very limited reports are found about non-Saccharomyces effects on grape fermentation. In this study, six non-Saccharomyces yeast strains, belonging to the genera Metschnikowia and Hanseniaspora, were screened for their effect on red wine colour and wine-making capacity under pure culture conditions and mixed with Saccharomyces. An artificial red grape must was prepared, containing a phenolic extract of Tannat grapes that allows monitoring changes of key phenol parameters during fermentation, but without skin solids in the medium. When fermented in pure cultures, S. cerevisiae produced higher concentrations of acetaldehyde and vitisin B (acetaldehyde reaction-dependent) compared to M. pulcherrima M00/09G, Hanseniaspora guillermondii T06/09G, H. opuntiae T06/01G, H. vineae T02/05F and H. clermontiae (A10/82Fand C10/54F). However, co-fermentation of H. vineae and H. clermontiae with S. cerevisiae resulted in a significantly higher concentration of acetaldehyde compared with the pure S. cerevisiae control. HPLC-DAD-MS analysis confirmed an increased formation of vitisin B in co-fermentation treatments when compared to pure Saccharomyces fermentation, suggesting the key role of acetaldehyde. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26888345

  3. Preparation of ordered mesoporous Ag/WO3 and its highly efficient degradation of acetaldehyde under visible-light irradiation

    A highly active photocatalyst, silver loaded mesoporous WO3, was successfully synthesized by an ultrasound assisted insertion method. The photodegradation of a common air pollutant acetaldehyde was adopted to evaluate the photocatalytic performance of the as-prepared sample under visible-light irradiation. The photocatalytic activity was about three and six times higher than that of pure mesoporous WO3 and nitrogen-doped TiO2, respectively. The photocatalytic mechanism was investigated to understand the much enhanced photocatalytic activity, which was mainly attributed to the largely improved electron-hole separation in the Ag-WO3 heterojunction.

  4. Pollution Whack-a-Mole: Ambient Acetaldehyde and the Introduction of E-10 Gasoline in the Northeast

    Steiner, Christopher

    2014-01-01

    This paper uses a complicated set of phase-ins and phase-outs of oxygenated motor fuel in the Northeast to determine whether E-10 ethanol-enhanced fuel contributes to acetaldehyde air pollution over the pre-ethanol methyl tertiary-buthyl ether (MTBE) fuel. Oil companies phased out MTBE because of groundwater pollution concerns, and now E-10 is the standard fuel in EPA reformulated gas areas. Using a difference-in-difference setup, I find a small level increase but a large percentage increase ...

  5. Air-sea fluxes of methanol, acetone, acetaldehyde, isoprene and DMS from a Norwegian fjord following a phytoplankton bloom in a mesocosm experiment

    V. Sinha

    2007-01-01

    Full Text Available The ocean's influence on volatile organic compounds (VOCs in the atmosphere is poorly understood. This work characterises the oceanic emission and/or uptake of methanol, acetone, acetaldehyde, isoprene and dimethyl sulphide (DMS as a function of photosynthetically active radiation (PAR and a suite of biological parameters. The measurements were taken following a phytoplankton bloom, in May/June 2005 with a proton transfer reaction mass spectrometer (PTR-MS, from mesocosm enclosures anchored in the Raunefjord, Southern Norway. The net flux of methanol was always into the ocean, and was stronger at night. Isoprene and acetaldehyde were emitted from the ocean, correlating with light (ravcorr, isoprene=0.49; ravcorr, acetaldehyde=0.70 and phytoplankton abundance. DMS was also emitted to the air but did not correlate significantly with light (ravcorr, dms=0.01. Under conditions of high biological activity and a PAR of ~450 μmol photons m−2 s−1, acetone was emitted from the ocean, otherwise it was uptaken. The inter-VOC correlations were highest between the day time emission fluxes of acetone and acetaldehyde (rav=0.96, acetaldehyde and isoprene (rav=0.88 and acetone and isoprene (rav=0.85. The mean fluxes for methanol, acetone, acetaldehyde, isoprene and DMS were −0.26 ng m−2 s−1, 0.21 ng m−2 s−1, 0.23 ng m−2 s−1, 0.12 ng m−2 s−1 and 0.3 ng m−2 s−1, respectively. This work shows that compound specific PAR and biological dependency should be used for estimating the influence of the global ocean on atmospheric VOC budgets.

  6. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: surface tension depression and secondary organic products

    Z. Li

    2011-07-01

    Full Text Available The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS, and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. A hemiacetal sulfate ester was tentatively identified in the formaldehyde-AS system. Acetaldehyde depresses surface tension to 65(±2 dyn cm−1 in pure water and 62(±1 dyn cm−1 in AS solutions. Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9 % reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.

  7. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: surface tension depression and secondary organic products

    Li, Z.; Schwier, A. N.; Sareen, N.; McNeill, V. F.

    2011-11-01

    The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs) by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS) solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS), and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. Acetaldehyde depresses surface tension to 65(±2) dyn cm-1 in pure water (a 10% surface tension reduction from that of pure water) and 62(±1) dyn cm-1 in AS solutions (a 20.6% reduction from that of a 3.1 M AS solution). Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9% reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.

  8. Study on Streptococcus thermophilus isolated from Qula and associated characteristic of acetaldehyde and diacetyl in their fermented milk.

    Zha, Musu; Yu, Jie; Zhang, Yong; Wang, Hongmei; Bai, Na; Qin, Yanting; Liangliang, De; Liu, Wenjun; Zhang, Heping; Bilige, Menghe

    2015-01-01

    In this study, the lactic acid bacterial population of Qula cheese from the Gansu and Sichuan provinces of China were isolated and identified. Eight strains of Streptococcus thermophilus were isolated, of which five strains were selected for further characterization based on their fermentation properties. The changes in a number of parameters, including titration acidity, pH, viable counts, PrtS protease activity and the production of acetaldehyde, diacetyl and organic acid, were monitored during fermentation and the storage of fermented milks produced by the respective strain. All of the strains displaying acidifying capacity and all five fermented milks maintained high viable counts of S. thermophilus from fermentation to storage. Our study found that the changes in the monitored parameters were strain-specific and varied considerably among the five tested strains. Fermented milks produced by strain IMAU80809 had the highest concentration of acetaldehyde and were most favorable in the sensory evaluation. This study confirms that Qula cheese is a good source for isolating novel lactic acid bacterial strains with different fermentation properties, which will be very useful for further development and industrialization of traditionally fermented dairy products. PMID:26018501

  9. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: Surface tension depression and secondary organic products

    Li, Zhi; Sareen, Neha; McNeill, V Faye

    2011-01-01

    The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs) by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS) solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS), and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. A hemiacetal sulfate ester was tentatively identified in the formaldehyde-AS system. Acetaldehyde depresses surface tension to 65(\\pm2) dyn/cm in pure water and 62(\\pm1) dyn/cm in AS solutions. Surface t...

  10. Photochemical fabrication of size-controllable gold nanoparticles on chitosan and their application on catalytic decomposition of acetaldehyde

    Yu, Chung-Chin [Department of Environmental Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Nano Materials Applications R and D Center, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Yang, Kuang-Hsuan, E-mail: khy@mail.vnu.edu.tw [Department of Chemical and Materials Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Nano Materials Applications R and D Center, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Liu, Yu-Chuan [Department of Chemical and Materials Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Nano Materials Applications R and D Center, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Chen, Bo-Chuen [Department of Chemical and Materials Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China)

    2010-07-15

    In this work, we report a new pathway to prepare size-controllable gold nanoparticles (NPs) on chitosan (Ch) in aqueous solutions for improving catalytic decomposition of acetaldehyde by pure gold NPs at room temperature. First, Au substrates were cycled in deoxygenated aqueous solutions containing 0.1N NaCl and 1 g/L Ch from -0.28 to +1.22 V vs Ag/AgCl at 500 mV/s for 200 scans. Then the solutions were irradiated with UV lights of different wavelengths to prepare size-controllable Au NPs on Ch. Experimental results indicate that the particle sizes of prepared NPs are increased when UV lights with longer wavelengths were employed. The particle sizes of resulted Au NPs can be controlled from 10 to 50 nm. Moreover, the decomposition of acetaldehydes in wines can be significantly enhanced by ca. 190% of magnitude due to the contribution of the adsorption of Au NPs on Ch.

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

    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

  12. One-Pot Synthesis of (S)-Baclofen via Aldol Condensation of Acetaldehyde with Diphenylprolinol Silyl Ether Mediated Asymmetric Michael Reaction as a Key Step.

    Hayashi, Yujiro; Sakamoto, Daisuke; Okamura, Daichi

    2016-01-01

    An efficient asymmetric total synthesis of (S)-baclofen was accomplished via a one-pot operation from commercially available materials using sequential reactions, such as aldol condensation of acetaldehyde, diphenylprolinol silyl ether mediated asymmetric Michael reaction of nitromethane, Kraus-Pinnick oxidation, and Raney Ni reduction. Highly enantioenriched baclofen was obtained in one pot with a good yield over four reactions. PMID:26636719

  13. Catalytic Upgrading of Biomass-Derived Compounds via C-C Coupling Reactions. Computational and Experimental Studies of Acetaldehyde and Furan Reactions in HZSM-5

    Liu, Cong [Argonne National Lab. (ANL), Argonne, IL (United States); Evans, Tabitha J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cheng, Lei [Argonne National Lab. (ANL), Argonne, IL (United States); Nimlos, Mark R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mukarakate, Calvin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Robichaud, David J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Assary, Rajeev S. [Argonne National Lab. (ANL), Argonne, IL (United States); Curtiss, Larry A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-10-02

    These catalytic C–C coupling and deoxygenation reactions are essential for upgrading of biomass-derived oxygenates to fuel-range hydrocarbons. Detailed understanding of mechanistic and energetic aspects of these reactions is crucial to enabling and improving the catalytic upgrading of small oxygenates to useful chemicals and fuels. Using periodic density functional theory (DFT) calculations, we have investigated the reactions of furan and acetaldehyde in an HZSM-5 zeolite catalyst, a representative system associated with the catalytic upgrading of pyrolysis vapors. Comprehensive energy profiles were computed for self-reactions (i.e., acetaldehyde coupling and furan coupling) and cross-reactions (i.e., acetaldehyde + furan) of this representative mixture. Major products proposed from the computations are further confirmed using temperature controlled mass spectra measurements. Moreover, the computational results show that furan interacts with acetaldehyde in HZSM-5 via an alkylation mechanism, which is more favorable than the self-reactions, indicating that mixing furans with aldehydes could be a promising approach to maximize effective C–C coupling and dehydration while reducing the catalyst deactivation (e.g., coke formation) from aldehyde condensation.

  14. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: surface tension depression and secondary organic products

    Z. Li

    2011-11-01

    Full Text Available The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS, and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. Acetaldehyde depresses surface tension to 65(±2 dyn cm−1 in pure water (a 10% surface tension reduction from that of pure water and 62(±1 dyn cm−1 in AS solutions (a 20.6% reduction from that of a 3.1 M AS solution. Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9% reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.

  15. Formation of the thioester, N,S-diacetylcysteine, from acetaldehyde and N,N'diacetylcystine in aqueous solution with ultraviolet light

    Weber, A.L.

    1981-05-01

    The thioester, N,S-diacetylcysteine, is formed during the illumination of phosphate buffered (pH 7.0) aqueous solutions of acetaldehyde and N,N'-diacetylcystine with ultraviolet light. The yield of N,S-diacetylcysteine relative to N-acetylcysteine and unidentified products progressively increases as ultraviolet light below 239 nm, 253 nm and 281 nm is cut off with optical filters. When ultraviolet light below 320 nm is removed with an optical filter, there is no detectable reaction. Illumination of 0.025 M N,N'-diacetylcystine with 0.5 M and 1.0 M acetaldehyde with filtered ultraviolet light gives, respectively, 20% and 80% yields of N,S-diacetylcysteine. In the reaction with 1.0 M acetyldehyde, N-acetylcysteine forms early in the reaction and later decreases with its conversion to N,S-diacetylcysteine. The prebiotic significance of these reactions is discussed.

  16. Formation of the thioester, N,S-diacetylcysteine, from acetaldehyde and N,N'diacetylcystine in aqueous solution with ultraviolet light

    The thioester, N,S-diacetylcysteine, is formed during the illumination of phosphate buffered (pH 7.0) aqueous solutions of acetaldehyde and N,N'-diacetylcystine with ultraviolet light. The yield of N,S-diacetylcysteine relative to N-acetylcysteine and unidentified products progressively increases as ultraviolet light below 239 nm, 253 nm and 281 nm is cut off with optical filters. When ultraviolet light below 320 nm is removed with an optical filter, there is no detectable reaction. Illumination of 0.025 M N,N'-diacetylcystine with 0.5 M and 1.0 M acetaldehyde with filtered ultraviolet light gives, respectively, 20% and 80% yields of N,S-diacetylcysteine. In the reaction with 1.0 M acetyldehyde, N-acetylcysteine forms early in the reaction and later decreases with its conversion to N,S-diacetylcysteine. The prebiotic significance of these reactions is discussed. (orig.)

  17. Visible-light photodecomposition of acetaldehyde by TiO2-coated gold nanocages: plasmon-mediated hot electron transport via defect states.

    Kodiyath, Rajesh; Manikandan, Maidhily; Liu, Lequan; Ramesh, Gubbala V; Koyasu, Satoshi; Miyauchi, Masahiro; Sakuma, Yoshiki; Tanabe, Toyokazu; Gunji, Takao; Duy Dao, Thang; Ueda, Shigenori; Nagao, Tadaaki; Ye, Jinhua; Abe, Hideki

    2014-12-21

    Skeletal gold nanocages (Au NCs) are synthesized and coated with TiO2 layers (TiO2-Au NCs). The TiO2-Au NCs exhibit enhanced photodecomposition activity toward acetaldehyde under visible light (>400 nm) illumination because hot electrons are generated over the Au NCs by local surface plasmon resonance (LSPR) and efficiently transported across the metal/semiconductor interface via the defect states of TiO2. PMID:25357137

  18. Quantification of acetaldehyde and carbon dioxide in the headspace of malignant and non-malignant lung cells in vitro by SIFT-MS

    Sule-Suso, J.; Pysanenko, Andriy; Španěl, Patrik; Smith, D.

    2009-01-01

    Roč. 134, č. 12 (2009), s. 2419-2425. ISSN 0003-2654 R&D Projects: GA ČR GA202/09/0800; GA ČR GA203/09/0256 Institutional research plan: CEZ:AV0Z40400503 Keywords : acetaldehyde * SIFT-MS * carbon dioxide Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.272, year: 2009

  19. Mechanistic insights into the formation of acetaldehyde and diethyl ether from ethanol over supported VO{subx}, MoO{subx}, and WO{subx} catalysts.

    Nair, H.; Gatt, J. E.; Miller, J. T.; Baertsch, C. D. (Chemical Sciences and Engineering Division); (Purdue University)

    2011-04-01

    Catalytic pathways are described for reactions of ethanol to acetaldehyde by oxidative dehydrogenation and of ethanol to diethyl ether by condensation over VO{sub x}-Al{sub 2}O{sub 3}, MoO{sub x}-Al{sub 2}O{sub 3}, and WO{sub x}-Al{sub 2}O{sub 3}. Isotopic labeling shows that acetaldehyde formation occurs via rate-determining C-H bond cleavage of the CH{sub 2} group in an adsorbed alkoxide followed by removal of surface oxygen in a Mars and van Krevelen redox mechanism (as confirmed by in situ X-ray absorption, diffuse reflectance infra-red Fourier transform spectroscopy and UV-visible spectroscopy); diethyl ether formation occurs in parallel via coupling and condensation of two adjacent ethoxy species. Using a combination of in situ spectroscopic and kinetic analysis, catalyst properties influencing the formation of acetaldehyde and ether from the common adsorbed ethoxy intermediate are elucidated. X-ray absorption analysis during anaerobic ethanol titration is used to preclude the involvement of terminal M{double_bond}O bonds during the reaction. A study of the activity of catalysts with the same MoO{sub x} domain size on Al{sub 2}O{sub 3}, TiO{sub 2}, and CeO{sub 2} supports and binary oxides of MoO{sub x} and WO{sub x} on Al{sub 2}O{sub 3} are used to prove that the active redox oxygen for acetaldehyde formation is the oxygen atom linking the active metal oxide domain to the support oxide. Ether formation ability of the metal oxide is related to the electronegativity of the active metal atom.

  20. On the physical interpretation of torsion-rotation parameters in methanol and acetaldehyde: Comparison of global fit and ab initio results

    Equilibrium structural constants and certain torsion endash rotation interaction parameters have been determined for methanol and acetaldehyde from ab initio calculations using GAUSSIAN 94. The substantial molecular flexing which occurs in going from the bottom to the top of the torsional potential barrier can be quantitatively related to coefficients of torsion endash rotation terms having a (1-cos ampersand hthinsp;3γ) dependence on torsional angle γ. The barrier height, six equilibrium structural constants characterizing the bottom of the potential well, and six torsion endash rotation constants are all compared to experimental parameters obtained from global fits to large microwave and far-infrared data sets for methanol and acetaldehyde. The rather encouraging agreement between the Gaussian and global fit results for methanol seems both to validate the accuracy of ab initio calculations of these parameters, and to demonstrate that the physical origin of these torsion endash rotation interaction terms in methanol lies primarily in structural relaxation with torsion. The less satisfactory agreement between theory and experiment for acetaldehyde requires further study. copyright 1999 American Institute of Physics

  1. Acetaldehyde partial oxidation on the Au(111) model catalyst surface: C-C bond activation and formation of methyl acetate as an oxidative coupling product

    Karatok, Mustafa; Vovk, Evgeny I.; Shah, Asad A.; Turksoy, Abdurrahman; Ozensoy, Emrah

    2015-11-01

    Partial oxidation of acetaldehyde (CH3CHO) on the oxygen pre-covered Au(111) single crystal model catalyst was investigated via Temperature Programmed Desorption (TPD) and Temperature Programmed Reaction Spectroscopy (TPRS) techniques, where ozone (O3) was utilized as the oxygen delivery agent providing atomic oxygen to the reacting surface. We show that for low exposures of O3 and small surface oxygen coverages, two partial oxidation products namely, methyl acetate (CH3COOCH3) and acetic acid (CH3COOH) can be generated without the formation of significant quantities of carbon dioxide. The formation of methyl acetate as the oxidative coupling reaction product implies that oxygen pre-covered Au(111) single crystal model catalyst surface can activate C-C bonds. In addition to the generation of these products; indications of the polymerization of acetaldehyde on the gold surface were also observed as an additional reaction route competing with the partial and total oxidation pathways. The interplay between the partial oxidation, total oxidation and polymerization pathways reveals the complex catalytic chemistry associated with the interaction between the acetaldehyde and atomic oxygen on catalytic gold surfaces.

  2. Simultaneous removal of ethanol,acetaldehyde and nitrogen oxides over V-Pd/γ-Al2O3-TiO2 catalyst

    Zhe Li; Jing Wang; Kai He; Xia An; Wei Huang; Kechang Xie

    2011-01-01

    V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method.X-ray diffraction(XRD),N2 adsorption-desorption(BET),X-ray photoelectron spectroscopy(XPS)and catalytic removal of ethanol,acetaldehyde and nitrogen oxides at low temperature(<300℃)were used to assess the properties of the catalysts.The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol,acetaldehyde and nitrogen oxides.The conversions of ethanol,acetaldehyde and nitrogen oxides at 250℃ were 100%,74.4% and 98.7%,respectively.V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface,and possessed a larger mole fraction of V4+species and unique PdO species on the surface,which can be attributed to the strong synergistic effect among palladium,vanadium and the carriers.The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4+and Pd2+species on the surface,which might be favorable for the formation of active sites.

  3. Formaldehyde and acetaldehyde exposure mitigation in US residences: in-home measurements of ventilation control and source control.

    Hult, E L; Willem, H; Price, P N; Hotchi, T; Russell, M L; Singer, B C

    2015-10-01

    Measurements were taken in new US residences to assess the extent to which ventilation and source control can mitigate formaldehyde exposure. Increasing ventilation consistently lowered indoor formaldehyde concentrations. However, at a reference air exchange rate of 0.35 h(-1), increasing ventilation was up to 60% less effective than would be predicted if the emission rate were constant. This is consistent with formaldehyde emission rates decreasing as air concentrations increase, as observed in chamber studies. In contrast, measurements suggest acetaldehyde emission was independent of ventilation rate. To evaluate the effectiveness of source control, formaldehyde concentrations were measured in Leadership in Energy and Environmental Design (LEED)-certified/Indoor airPLUS homes constructed with materials certified to have low emission rates of volatile organic compounds (VOC). At a reference air exchange rate of 0.35 h(-1), and adjusting for home age, temperature and relative humidity, formaldehyde concentrations in homes built with low-VOC materials were 42% lower on average than in reference new homes with conventional building materials. Without adjustment, concentrations were 27% lower in the low-VOC homes. The mean and standard deviation of formaldehyde concentration was 33 μg/m(3) and 22 μg/m(3) for low-VOC homes and 45 μg/m(3) and 30 μg/m(3) for conventional. PMID:25252109

  4. Concerns regarding 24-h sampling for formaldehyde, acetaldehyde, and acrolein using 2,4-dinitrophenylhydrazine (DNPH)-coated solid sorbents

    Herrington, Jason S.; Hays, Michael D.

    2012-08-01

    There is high demand for accurate and reliable airborne carbonyl measurement methods due to the human and environmental health impacts of carbonyls and their effects on atmospheric chemistry. Standardized 2,4-dinitrophenylhydrazine (DNPH)-based sampling methods are frequently applied for measuring gaseous carbonyls in the atmospheric environment. However, there are multiple short-comings associated with these methods that detract from an accurate understanding of carbonyl-related exposure, health effects, and atmospheric chemistry. The purpose of this brief technical communication is to highlight these method challenges and their influence on national ambient monitoring networks, and to provide a logical path forward for accurate carbonyl measurement. This manuscript focuses on three specific carbonyl compounds of high toxicological interest—formaldehyde, acetaldehyde, and acrolein. Further method testing and development, the revision of standardized methods, and the plausibility of introducing novel technology for these carbonyls are considered elements of the path forward. The consolidation of this information is important because it seems clear that carbonyl data produced utilizing DNPH-based methods are being reported without acknowledgment of the method short-comings or how to best address them.

  5. Effect of acid catalysts and accelerated aging on the reaction of methanol with hydroxy-acetaldehyde in bio-oil

    Bhattacharya, P.

    2010-05-01

    Full Text Available Bio-oil is a promising alternative source of energy produced from fast pyrolysis of biomass. Increasing the viscosity of bio-oil during storage is a major problem that can be controlled by the addition of methanol or other alcohols. This paper reports the results of our investigation of the reactions of short chain alcohols with aldehydes and acids in bio-oil. The reaction of methanol with hydroxyacetaldehyde (HA to form the acetal was catalyzed by the addition of 7 x 10-4 M strong acids such as sulfuric, hydrochloric, p-toluene sulfonic acid, and methanesulfonic acid. HA formed 2,2-dimethoxyethanol (DME, and at 60 oC the equilibrium was reached in less than one hour. Smaller amounts of DME were formed in the absence of strong acid. HA, acetaldehyde, and propanal formed their corresponding acetals when reacted with methanol, ethanol, 1-propanol or 1-butanol. Esters of acetic acid and hydroxyacetic acid were observed from reactions with these same four alcohols. Other acetals and esters were observed by GC/MS analysis of the reaction products. The results from accelerated aging experiments at 90 oC suggest that the presence of methanol slows polymerization by formation of acetals and esters from low molecular weight aldehydes and organic acids.

  6. Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats.

    Fulvio ePlescia

    2013-06-01

    Full Text Available Increasing evidence focuses on acetaldehyde (ACD as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking and relapse behaviour. Drug motivational properties are highlighted in operant paradigms which include response-contingent punishment, a behavioural equivalent of compulsive drug use despite adverse consequences.The aim of this study was thus to characterize ACD motivational and rewarding properties employing an operant-conflict paradigm in which rats, trained to lever press in order to get ACD solution (0.9%, undergo extinction, reinstatement and conflict sessions, according to a modified Geller-Seifter procedur. Furthermore the role played by CB1 receptor system in modulating ACD-induced effects were investigated through the administration of CB1 receptor antagonist, AM281 (1 mg/kg, i.p. during the extinction-, relapse- and conflict experiments.Our results indicate that ACD is able to induce and maintain an operant behaviour, a high number of responses during extinction, an increase in the lever presses during the reinstatement phase, and a higher emission of punished responses during the conflict experiments, when compared to controls.The administration of AM281 is able to decrease ACD-seeking behaviour during extinction, the number of lever presses during reinstatement and to strongly decrease the punished responses for ACD. Our data strengthen the idea that ACD may be responsible for the central effects of ethanol, and pinpoint at the CB1 system as one of the neural substrates underlying its addictive properties.

  7. Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats.

    Plescia, Fulvio; Brancato, Anna; Marino, Rosa A M; Cannizzaro, Carla

    2013-01-01

    Increasing evidence focuses on acetaldehyde (ACD) as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking, and relapse behavior. Drug motivational properties are highlighted in operant paradigms which include response-contingent punishment, a behavioral equivalent of compulsive drug use despite adverse consequences. The aim of this study was thus to characterize ACD motivational and rewarding properties employing an operant-conflict paradigm in which rats, trained to lever press in order to get ACD solution (0.9%), undergo extinction, reinstatement and conflict sessions, according to a modified Geller-Seifter procedure. Furthermore, the role played by CB1 receptor system in modulating ACD-induced effects were investigated through the administration of CB1 receptor antagonist, AM281 (1 mg/kg, i.p.) during the extinction-, relapse-, and conflict-experiments. Our results indicate that ACD is able to induce and maintain an operant behavior, a high number of responses during extinction, an increase in the lever presses during the reinstatement phase, and a higher emission of punished responses during the conflict experiments, when compared to controls. The administration of AM281 is able to decrease ACD-seeking behavior during extinction, the number of lever presses during reinstatement and to strongly decrease the punished responses for ACD. Our data strengthen the idea that ACD may be responsible for the central effects of ethanol, and pinpoint at the CB1 system as one of the neural substrates underlying its addictive properties. PMID:23781180

  8. Catalytic liquid-phase oxidation of acetaldehyde to acetic acid over a Pt/CeO2-ZrO2-SnO2/γ-alumina catalyst.

    Choi, Pil-Gyu; Ohno, Takanobu; Masui, Toshiyuki; Imanaka, Nobuhito

    2015-10-01

    Pt/CeO2-ZrO2-SnO2/γ-Al2O3 catalysts were prepared by co-precipitation and wet impregnation methods for catalytic oxidation of acetaldehyde to acetic acid in water. In the present catalysts, Pt and CeO2-ZrO2-SnO2 were successfully dispersed on the γ-Al2O3 support. Dependences of platinum content and reaction time on the selective oxidation of acetaldehyde to acetic acid were investigated to optimize the reaction conditions for obtaining both high acetaldehyde conversion and highest selectivity to acetic acid. Among the catalysts, a Pt(6.4wt.%)/Ce0.68Zr0.17Sn0.15O2.0(16wt.%)/γ-Al2O3 catalyst showed the highest acetaldehyde oxidation activity. On this catalyst, acetaldehyde was completely oxidized after the reaction at 0°C for 8hr, and the selectivity to acetic acid reached to 95% and higher after the reaction for 4hr and longer. PMID:26456607

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

    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.

  10. Effect of indole-3-carbinol on ethanol-induced liver injury and acetaldehyde-stimulated hepatic stellate cells activation using precision-cut rat liver slices.

    Guo, Yu; Wu, Xiao-Qian; Zhang, Chun; Liao, Zhang-Xiu; Wu, Yong; Xia, Zheng-Yuan; Wang, Hui

    2010-12-01

    1. Indole-3-carbinol (I3C), a major indole compound found in high levels in cruciferous vegetables, shows a broad spectrum of biological activities. However, few studies have reported the effect of I3C on alcoholic liver injury. In the present study, we investigated the protective effect of I3C on acute ethanol-induced hepatotoxicity and acetaldehyde-stimulated hepatic stellate cells (HSC) activation using precision-cut liver slices (PCLS). 2. Rat PCLS were incubated with 50 mmol/L ethanol or 350 μmol/L acetaldehyde, and different concentrations (100-400 μmol/L) of I3C were added into the culture system of these two liver injury models, respectively. Hepatotoxicity was assessed by measuring enzyme leakage and malondialdehyde (MDA) content in tissue. Activities of alcoholic enzymes were also determined. α-Smooth muscle actin (α-SMA), transforming growth factor (TGF-β(1) ) and hydroxyproline (HYP) were used as indices to evaluate the activation of HSC. In addition, matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of metalloproteinase (TIMP-1) were observed to estimate collagen degradation. 3. I3C significantly reduced the enzyme leakage in ethanol-treated slices. In I3C groups, cytochrome P450 (CYP) 2E1 activities were inhibited by 40.9-51.8%, whereas alcohol dehydrogenase (ADH) activity was enhanced 1.6-fold compared with the ethanol-treated group. I3C also showed an inhibitory effect against HSC activation and collagen production stimulated by acetaldehyde. After being incubated with I3C (400 μmol/L), the expression of MMP-1 was markedly enhanced, whereas TIMP-1 was decreased. 4. These results showed that I3C protected PCLS against alcoholic liver injury, which might be associated with the regulation of ethanol metabolic enzymes, attenuation of oxidative injury and acceleration of collagen degradation. PMID:20880187

  11. Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC.

    Gezginc, Y; Topcal, F; Comertpay, S; Akyol, I

    2015-03-01

    The present study was conducted to evaluate the lactic acid- and acetaldehyde-producing abilities of lactic acid bacterial species isolated from traditionally manufactured Turkish yogurts using HPLC. The lactic acid bacterial species purified from the yogurts were the 2 most widely used species in industrial yogurt production: Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria have the ability to ferment hexose sugars homofermentatively to generate lactic acid and some carbonyl compounds, such as acetaldehyde through pyruvate metabolism. The levels of the compounds produced during fermentation influence the texture and the flavor of the yogurt and are themselves influenced by the chemical composition of the milk, processing conditions, and the metabolic activity of the starter culture. In the study, morphological, biochemical, and molecular characteristics were employed to identify the bacteria obtained from homemade yogurts produced in different regions of Turkey. A collection of 91 Strep. thermophilus and 35 L. bulgaricus strains were investigated for their lactic acid- and acetaldehyde-formation capabilities in various media such as cow milk, LM17 agar, and aerobic-anaerobic SM17 agar or de Man, Rogosa, and Sharpe agar. The amounts of the metabolites generated by each strain in all conditions were quantified by HPLC. The levels were found to vary depending on the species, the strain, and the growth conditions used. Whereas lactic acid production ranged between 0 and 77.9 mg/kg for Strep. thermophilus strains, it ranged from 0 to 103.5 mg/kg for L. bulgaricus. Correspondingly, the ability to generate acetaldehyde ranged from 0 to 105.9 mg/kg in Strep. thermophilus and from 0 to 126.9 mg/kg in L. bulgaricus. Our study constitutes the first attempt to determine characteristics of the wild strains isolated from traditional Turkish yogurts, and the approach presented here, which reveals the differences in metabolite production abilities of the

  12. Involvement of acetaldehyde in seed deterioration of some recalcitrant woody species through the acceleration of aerobic respiration.

    Akimoto, Toshiyuki; Cho, Shinya; Yoshida, Hiroshi; Furuta, Hiroaki; Esashi, Yohji

    2004-02-01

    The rate of acetaldehyde (Ald) evolution in the deterioration of recalcitrant woody seeds was investigated. Four plant species, Ligustrum japonicum, Quercus serrata, Quercus myrsinaefolia and Camellia japonica, were used for the experiments. Similar to orthodox seeds, all of the recalcitrant seeds used contained Ald in addition to methanol and ethanol, although the amount of Ald in Camellia, a typical oil seed, was very small. These volatiles were accumulated in a container in which Ligustrum and Q. serrata seeds were stored for a short period. Moreover, all of the seeds that had been previously exposed to Ald for only 6 d at 3 or 13 degrees C lost their vigor rapidly in proportion to the concentration of Ald. The occasional removal by decompression of Ald accumulated in the container prolonged the life span of Q. serrata seeds from 4 to 6 months. These findings suggest that a short life span of the hydrated recalcitrant seeds may involve Ald synthesis as in the orthodox seeds. However, the action mechanism of Ald in Ligustrum and Quercus seeds in which storage substances were polysaccharides seems to differ slightly from that in orthodox seeds, because their aerobic respiration was significantly stimulated by exposure to exogenously applied Ald. It was, therefore, thought that the rapid deterioration of some recalcitrant seeds in woody species may result from a decline in vigor, not only due to the denaturation of functional proteins by Ald as in the orthodox seeds but also due to the rapid consumption of direct substrates for the Ald-stimulated aerobic respiration and related co-enzymes within seeds. In contrast, in the oil-bearing Camellia seeds, Ald was slightly produced and their aerobic respiration was not enhanced by Ald, although they were very sensitive to Ald. Desiccation storage of Camellia seeds caused the deterioration of their outer part, which was accelerated by exogenously applied Ald, which suggests that in Camellia Ald acts only to denature the

  13. Symthesis of Methyl Hexyl Acetaldehyde by Darzems Reactiom%Darzens 反应合成甲基己基乙醛

    陈文抗

    2014-01-01

    The solvent method for synthesizing methyl hexyl acetaldehyde,under the anhydrous and alkali catalysis,methyl nonyl ketone and α - halogenated acid ester via Darzens reaction to generate α,β - epoxy acid ester,saponification, acidification,heating and decarboxylation. The optimum process conditions acquired:petroleum ether as solvent,reaction temperature for 10 ~ 15℃ for condensation,condensation rate of reached 75% ;25% NaOH solution for saponification;2% sulfuric acidhyl sulfoxide for decarboxylation,the methyl hexyl acetaldehyde must rate reached 61% .%溶剂法缩合制甲基己基乙醛,以甲基壬酮与α-卤代酸酯在无水碱催化下,通过 Darzens 反应生成α,β-环氧酸酯,经皂化、酸化、加热脱羧而得,并对该工艺进行优化,缩合反应以石油醚为溶剂,反应温度为10~15℃,缩合收率达到75%;水解反应:用25%的 NaOH 溶液;脱羧反应:用2%的硫酸,使甲基己基乙醛总收率达到61%。

  14. Fructophilic characteristics of Fructobacillus spp. may be due to the absence of an alcohol/acetaldehyde dehydrogenase gene (adhE).

    Endo, Akihito; Tanaka, Naoto; Oikawa, Yo; Okada, Sanae; Dicks, Leon

    2014-04-01

    Fructophilic strains of Leuconostoc spp. have recently been reclassified to a new genus, i.e., Fructobacillus. Members of the genus are differentiated from Leuconostoc spp. by their preference for fructose on growth, requirement of an electron acceptor for glucose metabolism, and the inability to produce ethanol from the fermentation of glucose. In the present study, enzyme activities and genes involved in ethanol production were studied, since this is the key pathway for NAD(+)/NADH cycling in heterofermentative lactic acid bacteria. Fructobacillus spp. has a weak alcohol dehydrogenase activity and has no acetaldehyde dehydrogenase activity, whereas both enzymes are active in Leuconostoc mesenteroides. The bifunctional alcohol/acetaldehyde dehydrogenase gene, adhE, was described in Leuconostoc spp., but not in Fructobacillus spp. These results suggested that, due to the deficiency of the adhE gene, the normal pathway for ethanol production is absent in Fructobacillus spp. This leads to a shortage of NAD(+), and the requirement for an electron acceptor in glucose metabolism. Fructophilic characteristics, as observed for Fructobacillus spp., are thus due to the absence of the adhE gene, and a phenotype that most likely evolved as a result of regressive evolution. PMID:24352296

  15. Spectroscopy of the ground, first and second excited torsional states of acetaldehyde from 0.05 to 1.6 THz

    Smirnov, I. A.; Alekseev, E. A.; Ilyushin, V. V.; Margulés, L.; Motiyenko, R. A.; Drouin, B. J.

    2014-01-01

    We present a new global study of the millimeter wave, submillimeter wave and THz spectra of the lowest three torsional states of acetaldehyde (CH3CHO). New measurements have been carried out between 0.05 and 1.62 THz using three different spectrometers in IRA NASU (Ukraine), PhLAM Lille (France), and JPL (USA). The new data involving torsion-rotation transitions with J up to 66 and Ka up to 22 were combined with previously published measurements and fitted using the rho-axis-method torsion-rotation Hamiltonian. The final fit used 109 parameters to give an overall weighted root-mean-square deviation of 0.69 for the dataset consisting of 8748, 6959, and 4524 transitions belonging, respectively, to the ground, first, and second excited torsional states and 1481 Δvt ≠ 0 FIR transitions belonging to the torsional vt = 0 → 1 and 1 → 2 bands of the molecule. This investigation presents more than a twofold expansion in the J quantum number and almost fourfold expansion in the frequency range coverage for the acetaldehyde rotational spectrum.

  16. Flux measurement of methanol, acetaldehyde and other oxygenated VOCs from crop harvesting using proton-transfer-reaction mass spectrometry and surface layer gradient method

    PTR-MS technique was used to measure fluxes of various VOC's including oxygenates using surface layer gradient method. The VOC concentrations and temperature were measured at heights of about 0.5 m and 3.9 m above ground at field site in St. Johann in Tirol during and after grass cutting (24th and 25th of May 2000) in order to calculate fluxes. The sensible heat flux was obtained by a sonic anemometer with turbulence data analyzer. The major crop in this part of Austria are perennial grasses used for livestock farming. We observed VOC emission fluxes including methanol and acetaldehyde as the major volatile, C5 and C6 leaf wound compounds with lesser amounts and traces of acetone and butanone. This composition of VOC's is very similar to that released from slashed pasture grass. At the same time, VOC fluxes were measured with PTR-MS and eddy covariance method. Comparing the flux data of methanol and acetaldehyde of both days have shown very similar results. (author)

  17. Effect of the allelic variants of aldehyde dehydrogenase ALDH2*2 and alcohol dehydrogenase ADH1B*2 on blood acetaldehyde concentrations

    Peng Giia-Sheun

    2009-01-01

    Full Text Available Abstract Alcoholism is a complex behavioural disorder. Molecular genetics studies have identified numerous candidate genes associated with alcoholism. It is crucial to verify the disease susceptibility genes by correlating the pinpointed allelic variations to the causal phenotypes. Alcohol dehydrogenase (ADH and aldehyde dehydrogenase (ALDH are the principal enzymes responsible for ethanol metabolism in humans. Both ADH and ALDH exhibit functional polymorphisms among racial populations; these polymorphisms have been shown to be the important genetic determinants in ethanol metabolism and alcoholism. Here, we briefly review recent advances in genomic studies of human ADH/ALDH families and alcoholism, with an emphasis on the pharmacogenetic consequences of venous blood acetaldehyde in the different ALDH2 genotypes following the intake of various doses of ethanol. This paper illustrates a paradigmatic example of phenotypic verifications in a protective disease gene for substance abuse.

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

    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

  19. Mechanistic insights into the formation of acetaldehyde and diethyl ether from ethanol over support VO{sub x}, MoO{sub x}, and WO{sub x} catalysts.

    Nair, H.; Gatt, J. E.; Miller, J. T.; Baertsch, C. D. (Chemical Sciences and Engineering Division); (Purdue Univ.)

    2011-04-01

    Catalytic pathways are described for reactions of ethanol to acetaldehyde by oxidative dehydrogenation and of ethanol to diethyl ether by condensation over VO{sub x}-Al{sub 2}O{sub 3}, MoO{sub x}-Al{sub 2}O{sub 3}, and WO{sub x}-Al{sub 2}O{sub 3}. Isotopic labeling shows that acetaldehyde formation occurs via rate-determining C-H bond cleavage of the CH{sub 2} group in an adsorbed alkoxide followed by removal of surface oxygen in a Mars and van Krevelen redox mechanism (as confirmed by in situ X-ray absorption, diffuse reflectance infra-red Fourier transform spectroscopy and UV-visible spectroscopy); diethyl ether formation occurs in parallel via coupling and condensation of two adjacent ethoxy species. Using a combination of in situ spectroscopic and kinetic analysis, catalyst properties influencing the formation of acetaldehyde and ether from the common adsorbed ethoxy intermediate are elucidated. X-ray absorption analysis during anaerobic ethanol titration is used to preclude the involvement of terminal MO bonds during the reaction. A study of the activity of catalysts with the same MoO{sub x} domain size on Al{sub 2}O{sub 3}, TiO{sub 2}, and CeO{sub 2} supports and binary oxides of MoO{sub x} and WO{sub x} on Al{sub 2}O{sub 3} are used to prove that the active redox oxygen for acetaldehyde formation is the oxygen atom linking the active metal oxide domain to the support oxide. Ether formation ability of the metal oxide is related to the electronegativity of the active metal atom.

  20. Ethanol-induced oxidative stress and acetaldehyde formation in rat mammary tissue: Potential factors involved in alcohol drinking promotion of breast cancer

    Recent studies from our laboratory provided evidence that part of the carcinogenic effects of ethanol consumption might be related to its in situ metabolism at cytosolic and microsomal levels, to the mutagen acetaldehyde and to hydroxyl and 1-hydroxyethyl radicals. In this work, we report on our experiments where Sprague-Dawley female rats were exposed to the standard Lieber and De Carli diet for 28 days. We observed: the induction of the (xanthineoxidoreductase mediated) cytosolic and microsomal (lipoxygenase mediated) pathways of ethanol metabolism; promotion of oxidative stress as shown by increased formation of lipid hydroperoxides; delay in the t-butylhydroperoxide induced chemiluminiscence, and a significant decrease in protein sulfhydryls. In addition, the epithelial cells showed ultrastructural alterations consisting of markedly irregular nuclei, with frequent invaginations at the level of the nuclear envelope, condensation of chromatin around the inner nuclear membrane, and marked dilatation of the nuclear pores showing filamentous material exiting to the cytoplasm. In conclusion, the presence in mammary epithelial cells of cytosolic and microsomal pathways of ethanol bioactivation to carcinogenic and to tumorigenic metabolites might play a role in alcohol promotion of breast cancer

  1. Hydrogen bonding interaction of small acetaldehyde clusters studied with core-electron excitation spectroscopy in the oxygen K-edge region

    In order to examine inner-shell electron excitation spectra of molecular clusters with strong multipole interactions, excitation spectra and time-of-flight (TOF) fragment-mass spectra of small acetaldehyde (AA) clusters have been studied under the beam conditions. The TOF spectra at the oxygen K-edge region showed an intense growth of the protonated clusters, MnH+ (M=CH3CHO) in the cluster beams. 'cluster-specific' excitation spectra could be generated by monitoring partial-ion-yields of the protonated clusters. The most intense band of O1s→π*CO was found to shift to a higher energy by 0.15 eV relative to the monomer band upon clusterization. X-ray absorption spectra (XAS) were also calculated for the representative dimer configurations using a computer modelling program based on the density functional theory. The XAS prediction for the most stable (non-planar) configuration was found to give a close comparison with the cluster-band shift observed. The band shift was interpreted as being due to the HOMO-LUMO interaction within the complex where a contribution of vibrationally blue-shifting hydrogen bonding could be identified.

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

    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. PMID:26159709

  3. Liquid-Phase Aldol Condesation of Acetaldehyde and Its Kinetics%乙醛液相羟醛缩合反应工艺和动力学

    伍艳辉; 任伟丽; 梁泽磊; 刘仲能; 吴高胜

    2013-01-01

    考察了KOH,NaOH,Na2CO3,NaOH和Na2CO3混合碱,三乙胺及阴离子交换树脂在乙醛缩合反应过程中的催化性能,以及反应体系的pH值和温度对反应的影响.结果表明,以Na2CO3为催化剂有利于维持反应体系pH稳定,当反应体系pH值为11~12,反应温度35℃时,反应转化率和选择性较高.在不同温度和pH值时进行动力学研究,得到pH值分别为10.4,11.0和11.4的动力学方程和相应的参数,其中pH值为11.4时,反应活化能最小.%The catalytic performance of different catalysts, KOH, NaOH, Na2CO3, mixed alkalis of NaOH and Na2CO3, triethylamine, and anionic exchange resin, in aldol condensation of acetaldehyde, were examined. The effects of solution pH level and reaction temperature on the reaction extent were investigated. The results indicate that a relatively constant pH level could be maintained with Na2CO3 as the catalyst. The reaction has a high conversion and a high selectivity at the reaction temperature of 35 ℃ and the pH range of 11-12. Kinetic studies were then carried out with Na2CO3 as the catalyst at different reaction temperatures and pH levels. The kinetic equations and the corresponding parameters were finally obtained for pH level of 10.4, 11.0, and 11.4, respectively. The activation energy at pH value of 11.4 is the lowest.

  4. Solvent Effects on Nuclear Magnetic Resonance 2J(C,Hf and 1J(C,Hf Spin–Spin Coupling Constants in Acetaldehyde

    Angel Esteban

    2003-02-01

    Full Text Available Abstract: The known solvent dependence of 1J(Cc,Hf and 2J(C1,Hf couplings in acetaldehyde is studied from a theoretical viewpoint based on the density functional theory approach where the dielectric solvent effect is taken into account with the polarizable continuum model. The four terms of scalar couplings, Fermi contact, paramagnetic spin orbital, diamagnetic spin orbital and spin dipolar, are calculated but the solvent effect analysis is restricted to the first term since for both couplings it is by far the dominant contribution. Experimental trends of Δ1J(Cc,Hf and Δ2J(C1,Hf Vs ε (the solvent dielectric constant are correctly reproduced although they are somewhat underestimated. Specific interactions between solute and solvent molecules are studied for dimethylsulfoxide, DMSO, solutions considering two different one-to-one molecular complexes between acetaldehyde and DMSO. They are determined by interactions of type C=O---H---C and S=O---H---C, and the effects of such interactions on 1J(Cc,Hf and 2J(C1,Hf couplings are analyzed. Even though only in a semiquantitative way, it is shown that the effect of such interactions on the solvent effects, of Δ1J(Cc,Hf and Δ2J(C1,Hf, tend to improve the agreement between calculated and experimental values. These results seem to indicate that a continuum dielectric model has not enough flexibility for describing quantitatively solvent effects on spin-spin couplings. Apparently, even for relatively weak hydrogen bonding, the contribution from “direct” interactions is of the same order of magnitude as the “dielectric” effect.

  5. GC Determination of Acetaldehyde, Acrolein and Acrylonitrile in Water with Purge and Trap Technique%吹扫捕集-气相色谱法测定水中乙醛、丙烯醛、丙烯腈

    陆文娟; 王晋宇; 陈玲瑚; 赵辰

    2011-01-01

    Purge and trap technique was applied in the GC determination of acetaldehyde, acrolein and acrylonitrile in water. The analytes were purged, trapped and thermodesorbed using the Trap Vocarb 3000, and determined by CR2 with flame ionization detector (FID). Linear relationships between values of peak area and mass concentration of acetaldehyde, acrolein and acrylonitrile obtained were same in the range of 0. 020--0.20 mg·L^-1 , with detection limits (3S/N) of 0. 005, 0. 010, 0. 001mg·L^-1 respectively. Tests for recovery and precision were made by standard addition method, values of recovery found were in the range of 90. 0%-110.0% and values of RSD's (n=7) were less than 50%.%提出了吹扫捕集-气相色谱法测定水中乙醛、丙烯醛和丙烯腈的分析方法。样品用Trap Vocarb 3000捕集阱吹扫、捕集及热解析后,用气相色谱法氢火焰离子化检测器分析。3种化合物的质量浓度在0.020~0.20mg·L^-1的相同范围内与其峰面积呈线性关系,方法的检出限(3S/N)分别为0.005,0.010,0.001mg·L^-。标准加入回收率在90.0%~110.0%之间,相对标准偏差(n=7)均小于5%。

  6. 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

    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

  7. Impact of engineered Streptococcus thermophilus trains overexpressing glyA gene on folic acid and acetaldehyde production in fermented milk Impacto de linhagens de Streptococcus thermophilus com aumento da expressão do gene glyA na produção de ácido folico e acetaldeído em leite fermentado

    Ana Carolina Sampaio Dória Chaves

    2003-11-01

    Full Text Available The typical yogurt flavor is caused by acetaldehyde produced through many different pathways by the yogurt starter bacteria L. bulgaricus and S. thermophilus. The attention was focused on one specific reaction for acetaldehyde and folic acid formation catalyzed by serine hydroxymethyltransferase (SHMT, encoded by the glyA gene. In S. thermophilus, this enzyme SHMT also plays the typical role of the enzyme threonine aldolase (TA that is the interconvertion of threonine into glycine and acetaldehyde. The behavior of engineered S. thermophilus strains in milk fermentation is described, folic acid and acetaldehyde production were measured and pH and counts were followed. The engineered S. thermophilus strains StA2305 and StB2305, have the glyA gene (encoding the enzyme serine hydroxymethyltransferase overexpressed. These engineered strains showed normal growth in milk when it was supplemented with Casitione. When they were used in milk fermentation it was observed an increase in folic acid and in acetaldehyde production by StA2305 and for StB2305 it was noticed a significative increase in folic acid formation.O acetaldeído, responsável pelo sabor e aroma característicos de iogurte, é produzido por diferentes vias metabólicas pelas bactérias lácticas: Streptococcus thermophilus (S. thermophilus e Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus. Neste trabalho, a atenção foi focada especificamente na reação para a formação de acetaldeído e de ácido fólico, catalisada pela enzima serina hidroximetil transferase (SHMT, codificada pelo gene glyA. A enzima SHMT catalisa diversas reações e, no caso da bactéria S. thermophilus, ela exerce também a atividade característica da enzima treonina aldolase (TA, definida como a interconversão do aminoácido treonina em glicina e acetaldeído. Foram construídas linhagens de S. thermophilus (StA2305 e StB2305 com super expressão do gene glyA. Estas linhagens modificadas apresentaram

  8. Acetaldehyde dehydrogenase 2 activation inhibits myocardial ischemia-reperfusion injury in senescent rats%激活乙醛脱氢酶2抑制老年大鼠心肌缺血再灌注损伤

    邢媛; 殷玥; 石曌玲; 李晨; 王博文; 王衍帅; 高峰; 马恒

    2013-01-01

    Objective Aging heart shows significantly reduced tolerance to myocardial ischemia/reperfusion (I/R) injury, so senescent heart is prone to be damaged by the injury. This study was designed to investigate the protective effect of acetaldehyde dehydrogenase 2 (ALDH2) agonist Alda-1 in aging rats after myocardial I/R injury. Methods A total of 40 aging male Sprague Dawley (SD) rats (at an age of 20 to 22 months) were randomized into I/R group (I/R) and Alda-1 group (I/R + Alda). Another 40 adult rats at an age of 3 to 4 months served as adult control. Rat acute myocardial I/R model was established by ligation of left anterior descending artery for 30min followed by reperfusion for 4h. Alda-l(16mg/kg) and normal saline at the same volume were intravenously infused at a flow rate of 2ml/(kg · h) into the left ventricle of corresponding rats in 5min before reperfusion. The left ventricular pressure was monitored at the same time. At the end of 4 hours reperfusion, ALDH2 activity, reactive oxygen species (ROS) production, and protein carbonylation in the myocardial tissue were measured. Serum level of lactate dehydrogenase (LDH) was tested. Results A significant decrease in ALDH2 activity was observed in the aging hearts, but this effect was blocked by Alda-1. Compared with the adult hearts, myocardial I/R injury was significantly aggravated in aging hearts, which were evidenced by reduced ± LVdP/dtmax and increased serum level of LDH (P < 0.05). ALDH2 activator infusion during reperfusion effectively suppressed the above mentioned ischemic injury in the aging hearts (P < 0.05). Furthermore, protein carbonylation and ROS production in the myocardium were increased in the aging hearts compared with the adult hearts (P < 0.05), which was attenuated by Alda-1 treatment. Conclusion Activating myocardial ALDH2 significantly improves the resistance ability to myocardial I/R injury in aging heart. ALDH2-induced cardiac protection may be through suppressing myocardial I

  9. Effect of caffeine on signaling transduction of TGF-β1 and CTGF in hepatic stellate cell-T6 stimulated by acetaldehyde%咖啡因对乙醛诱导的HSC-T6中TGF-β1,CTGF信号转导通路的影响

    管文婕; 吕雄文; 杨万枝; 李俊

    2012-01-01

    Objective To explore the effect of caffeine on proliferation in hepatic stellate cell stimulated by acetaldehyde and its signaling pathway of TGF-β and CTGF. Methods Trials are divided into normal group( regular training ), model group, adenosine receptor group,which were given caffeine( 4 mmol · L-1 ),adenosine A2A receptor antagonist ZM241385( 1 μmol · L-1 ),adenosine A2A receptor agonists CGS21680( 1 μmol · L-1 ),caffeine + CGS21680,ZM241385 + CGS21680 and HSC-T6 respectively,stimulated by acetaldehyde after 1 h,before continueing to cultivate 48 h. The protein expression of a-SMA was analyzed by immunocytochemistry methods. The mR-NA expressions of TGF-β1 and CTGF were measured by RT-PCR. The protein expression of CTGF was analyzed by western blot methods. Results Caffeine or ZM241385 treatment inhibited the increase expressions of TGF-β1, CTGF, α-SMA in the HSC-T6,likewise,as with CGS21680 plus caffeine or ZM241385 groups, caffeine or ZM241385 prevented the adenosine A2A receptor agonist from stimulating an increase in hepatic stellate cell. Conclusion Caffeine can suppress the activation of α-SMA in HSC-T6 stimulated by acetaldehyde. Caffeine treatment inhibited the increase expressions of TGF-βl and CTGF in the HSC-T6,the mechanisms of which may be related to the expression of adenosine A2A receptor.%目的 探讨咖啡因(caffeine)对乙醛诱导的大鼠肝星状细胞系(Hepatic Stellate Cell-T6,HSC-T6)中转化生长因子-β1(Transforming Growth Factor-β1,TGF-β1),结缔组织生长因子(Connective Tissue Growth Factor,CTGF)信号转导通路的影响.方法 实验设正常组(常规培养),模型组及腺苷受体(Adenosine Receptor,AR)调节剂干预组.分别给予caffeine(4 mmol·L-1)[1-2],腺苷A2A受体拮抗剂ZM241385(1 μmol·L-1)[3],腺苷A2A受体激动剂CGS21680(1 μmol·L-1)[3],caffeine+CGS21680,ZM241385+CGS21680 与HSC-T6共同培养,1 h后加入终浓度200 μmol·L-1的乙醛刺激(每12 h补充1次),继续培养48 h.采

  10. Candida yeasts and carcinogenic acetaldehyde in upper digestive tract carcinogenesis

    Nieminen, Mikko

    2014-01-01

    Cancers of the upper digestive tract (oral, pharyngeal, laryngeal, oesophageal and stomach) are among the ten most common cancers worldwide and are associated with high mortality and morbidity. Despite improved treatment strategies, the prognosis of these cancers remains poor. The main aetiological factors for the upper digestive tract cancers are alcohol consumption and smoking. Dietary and genetic factors can also contribute to an increased risk. Alcohol consumption, smoking and poor oral h...

  11. Quantification by SIFT-MS of acetaldehyde released by lung cells in a 3D model

    Rutter, A. V.; Chippendale, T. W. E.; Yang, Y.; Španěl, Patrik; Smith, D.; Sule-Suso, J.

    2013-01-01

    Roč. 138, č. 1 (2013), s. 91-95. ISSN 0003-2654 Institutional support: RVO:61388955 Keywords : tube mass spectrometry * volatile organic compounds * in-vitro Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.906, year: 2013

  12. Ethanol-derived acetaldehyde: pleasure and pain of alcohol mechanism of action.

    Marco Diana

    2013-07-01

    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.

  13. Water and acetaldehyde in HH212: The first hot corino in Orion

    Codella, C; Cabrit, S; Podio, L; Bachiller, R; Fontani, F; Gusdorf, A; Lefloch, B; Leurini, S; Tafalla, M

    2016-01-01

    Aims: Using the unprecedented combination of high resolution and sensitivity offered by ALMA, we aim to investigate whether and how hot corinos, circumstellar disks, and ejected gas are related in young solar-mass protostars. Methods: We observed CH$_3$CHO and deuterated water (HDO) high-excitation ($E_{\\rm u}$ up to 335 K) lines towards the Sun-like protostar HH212--MM1. Results: For the first time, we have obtained images of CH$_3$CHO and HDO emission in the inner $\\simeq$ 100 AU of HH212. The multifrequency line analysis allows us to contrain the density ($\\geq$ 10$^{7}$ cm$^{-3}$), temperature ($\\simeq$ 100 K), and CH$_3$CHO abundance ($\\simeq$ 0.2--2 $\\times$ 10$^{-9}$) of the emitting region. The HDO profile is asymmetric at low velocities ($\\leq$ 2 km s$^{-1}$ from $V_{\\rm sys}$). If the HDO line is optically thick, this points to an extremely small ($\\sim$ 20--40 AU) and dense ($\\ge$ 10$^{9}$ cm$^{-3}$) emitting region. Conclusions: We report the first detection of a hot corino in Orion. The HDO asymm...

  14. Water and acetaldehyde in HH212: The first hot corino in Orion

    Codella, C.; Ceccarelli, C.; Cabrit, S.; Gueth, F.; Podio, L.; Bachiller, R.; Fontani, F.; Gusdorf, A.; Lefloch, B.; Leurini, S.; Tafalla, M.

    2016-02-01

    Aims: Using the unprecedented combination of high resolution and sensitivity offered by ALMA, we aim to investigate whether and how hot corinos, circumstellar disks, and ejected gas are related in young solar-mass protostars. Methods: We observed CH3CHO and deuterated water (HDO) high-excitation (Eu up to 335 K) lines towards the Sun-like protostar HH212-MM1. Results: For the first time, we have obtained images of CH3CHO and HDO emission in the inner ≃100 AU of HH212. The multifrequency line analysis allows us to contrain the density (≥107 cm-3), temperature (≃100 K), and CH3CHO abundance (≃0.2-2 × 10-9) of the emitting region. The HDO profile is asymmetric at low velocities (≤2 km s-1 from Vsys). If the HDO line is optically thick, this points to an extremely small (~20-40 AU) and dense (≥109 cm-3) emitting region. Conclusions: We report the first detection of a hot corino in Orion. The HDO asymmetric profile indicates a contribution of outflowing gas from the compact central region, possibly associated with a dense disk wind.

  15. Genetic determinants of both ethanol and acetaldehyde metabolism influence alcohol hypersensitivity and drinking behaviour among Scandinavians

    Linneberg, A; Gonzalez-Quintela, A; Vidal, C;

    2010-01-01

    Although hypersensitivity reactions following intake of alcoholic drinks are common in Caucasians, the underlying mechanisms and clinical significance are not known. In contrast, in Asians, alcohol-induced asthma and flushing have been shown to be because of a single nucleotide polymorphism (SNP...

  16. Azo dyes photobleaching and operando FTIR study of acetaldehyde photoinduced decomposition on bismuth doped titania

    Henych, Jiří; Štengl, Václav; Mattsson, A.; Österlund, L.

    Thessaloniki: Aristotle University of Thessaloniki, 2014, 41 PC-2-4. [European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications (SPEA) /8./. Thessaloniki (GR), 25.6.2014-28.6.2014] Institutional support: RVO:61388980 Keywords : bismuth doped titania * photocatalytic Subject RIV: CA - Inorganic Chemistry

  17. Relative tropospheric photolysis rates of acetaldehyde and formaldehyde measured at the European Photoreactor Facility

    Nilsson, Elna Johanna Kristina; Bache-Andreassen, Lihn; Johnson, Matthew Stanley;

    2009-01-01

    The photolysis rates of HCHO, DCDO, CH3CHO, and CH3CDO are studied by long-path FTIR spectroscopy in natural tropospheric conditions at the European Photoreactor Facility (EUPHORE) in Valencia, Spain. Average relative photolysis rates jHCHO/jDCDO ) 3.15 ( 0.08 and jCH3CHO/jCH3CDO ) 1.26 ( 0.03 are...

  18. VizieR Online Data Catalog: Mono-13C acetaldehydes mm/submm wave spectra (Margules+,

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

    2015-06-01

    This paper is a continuation of a series of studies conducted in PhLAM Lille (France) that are devoted to the investigations of the spectra of different isotopic species of astrophysical molecules. We present a new study of the 13CH3CHO and CH313CHO spectra with measurements and analysis extended up to 945GHz. (6 data files).

  19. Roaming is the dominant mechanism for molecular products in acetaldehyde photodissociation

    Heazlewood, Brianna R.; Jordan, Meredith J. T.; Kable, Scott H.; Selby, Talitha M.; Osborn, David L.; Shepler, Benjamin C.; Braams, Bastiaan J.; Joel M. Bowman

    2008-01-01

    Reaction pathways that bypass the conventional saddle-point transition state (TS) are of considerable interest and importance. An example of such a pathway, termed “roaming,” has been described in the photodissociation of H2CO. In a combined experimental and theoretical study, we show that roaming pathways are important in the 308-nm photodissociation of CH3CHO to CH4 + CO. The CH4 product is found to have extreme vibrational excitation, with the vibrational distribution peaked at ≈95% of the...

  20. Real-time trace gas sensing of ethylene, propanal and acetaldehyde from human skin in vivo.

    Moeskops, B.W.M.; Steeghs, M.M.L.; Swam, K. van; Cristescu, S.M.; Scheepers, P.T.J.; Harren, F.J.M.

    2006-01-01

    Trace gases emitted by human skin in vivo are monitored non-invasively and in real time using laser-based photoacoustic detection and proton-transfer reaction mass spectrometry. A small quartz cuvette is placed on the skin to create a headspace from which a carrier gas transports the skin emissions

  1. Azo dyes photobleaching and operando FTIR study of acetaldehyde photoinduced decomposition on bismuth doped titania

    Henych, Jiří; Štengl, Václav; Mattsson, A.; Österlund, L.

    Thessaloniki : Aristotle University of Thessaloniki, 2014. s. 101. [European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications (SPEA) /8./. 25.6.2014-28.6.2014, Thessaloniki] Institutional support: RVO:61388980 Keywords : bismuth doped titania Subject RIV: CA - Inorganic Chemistry

  2. Quantification of Acetaldehyde Released by Lung Cancer Cells in vintro Using Selected Ion Flow Tube Mass Spectrometry

    Smith, D.; Wang, T.; Sule-Suso, J.; Španěl, Patrik; El Haj, A.

    2003-01-01

    Roč. 17, - (2003), s. 845-850. ISSN 0951-4198 R&D Projects: GA ČR GA202/03/0827; GA ČR GA203/02/0737 Institutional research plan: CEZ:AV0Z4040901 Keywords : stage ranal-failure * trace gas-analysis * quantitative-analysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.789, year: 2003

  3. Oscillatory Ignitions and Cool Flames Accompanying the Non-Isothermal Oxidation of Acetaldehyde in a Well Stirred, Flow Reactor

    Gray, P.; Griffiths, J. F.; Hasko, S. M.; Lignola, P.-G.

    1981-02-01

    At the various boundaries between the five regions, sharp jumps occur from one kind of behaviour to another. At three segments of the boundary, there is hysteresis, the jumps occurring at different temperatures during heating (I --> II, III or IV) and cooling (II, III or IV --> I) traverses. There are thus regions of bistability, where identical external conditions - vessel temperatures, reactant pressures and flow rates - can give rise to alternative states inside the reactor. The two non-oscillatory, stationary states have different characters: I is a stable node and V is a stable focus. In region I, the reaction rate increases with temperature; but in region V, both reaction rate and extent of self-heating show a near-zero or negative temperature-coefficient.

  4. Effect of the allelic variants of aldehyde dehydrogenase ALDH2*2 and alcohol dehydrogenase ADH1B*2 on blood acetaldehyde concentrations

    Peng Giia-Sheun; Yin Shih-Jiun

    2009-01-01

    Abstract Alcoholism is a complex behavioural disorder. Molecular genetics studies have identified numerous candidate genes associated with alcoholism. It is crucial to verify the disease susceptibility genes by correlating the pinpointed allelic variations to the causal phenotypes. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes responsible for ethanol metabolism in humans. Both ADH and ALDH exhibit functional polymorphisms among racial populations; the...

  5. 乙醇脱氢制备乙醛适宜温度的选择%Discussion on Optimum Temperature for Dehydrogenation of Ethanol to Acetaldehyde

    丁爱军; 王金龙

    2011-01-01

    从化学热力学角度探讨乙醇直接脱氢和氧化脱氢的反应属性,认为直接脱氢的反应温度应高于322.5℃.说明决定反应温度的相关要素,对化学教学中相应的反应温度提出建议.

  6. In Situ FTIR Spectroscopy Study of the Photodegradation of Acetaldehyde and azo Dye Photobleaching on Bismuth-Modified TiO2

    Henych, Jiří; Štengl, Václav; Mattsson, A.; Österlund, L.

    2015-01-01

    Roč. 91, č. 1 (2015), s. 48-58. ISSN 0031-8655 Institutional support: RVO:61388980 Keywords : TITANIUM-DIOXIDE PHOTOCATALYSTS * RAY PHOTOELECTRON-SPECTROSCOPY * DOPED TIO2 * SURFACE * ADSORPTION Subject RIV: CA - Inorganic Chemistry Impact factor: 2.266, year: 2014

  7. Technical Note: Concerns regarding 24-h sampling for formaldehyde, acetaldehyde, and acrolein using 2,4-dinitrophenylhydrazine (DNPH)-coated solid sorbents

    A wide variety of natural and anthropogenic sources emit airborne carbonyls such as aldehydes (RCHO) and ketones (R1COR2). Vegetation, food, forest fires, fossil fuel combustion, disinfectants, fumigants, preservatives, and resins are a few examples of primary carbonyl sources. T...

  8. Study on Aldol Condensation of Acetaldehyde and Formaldehyde%甲醛、乙醛气相缩合生成丙烯醛的研究

    杨菊群

    2008-01-01

    对SiO2及其用碱土金属、稀土金属修饰的混合氧化物催化剂进行了表征,并研究了其对甲醛、乙醛缩合生成丙烯醛的催化性能,详细考察了甲醛、乙醛的摩尔比;反应温度;投料速度对乙醛的转化率和生成丙烯醛的选择性等的影响.

  9. The thiocarbamate disulphide drug, disulfiram induces osteopenia in rats by inhibition of osteoblast function due to suppression of acetaldehyde dehydrogenase activity.

    Mittal, Monika; Khan, Kainat; Pal, Subhashis; Porwal, Konica; China, Shyamsundar Pal; Barbhuyan, Tarun K; Baghel, Khemraj S; Rawat, Tara; Sanyal, Sabyasachi; Bhadauria, Smrati; Sharma, Vishnu L; Chattopadhyay, Naibedya

    2014-05-01

    Dithiocarbamates (DTC), a sulfhydryl group containing compounds, are extensively used by humans that include metam and thiram due to their pesticide properties, and disulfiram (DSF) as an alcohol deterrent. We screened these DTC in an osteoblast viability assay. DSF exhibited the highest cytotoxicity (IC50 488nM). Loss in osteoblast viability and proliferation was due to induction of apoptosis via G1 arrest. DSF treatment to osteoblasts reduced glutathione (GSH) levels and exogenous addition of GSH prevented DSF-induced reactive oxygen species generation and osteoblast apoptosis. DSF also inhibited osteoblast differentiation in vitro and in vivo, and the effect was associated with inhibition of aldehyde dehydrogenase (ALDH) activity. Out of various ALDH isozymes, osteoblasts expressed only ALDH2 and DSF downregulated its transcript as well as activity. Alda-1, a specific activator of ALDH2, stimulated osteoblast differentiation. Subcutaneous injection of DSF over the calvarium of new born rats reduced the differentiation phenotype of calvarial osteoblasts but increased the mRNA levels of Runx-2 and osteocalcin. DSF treatment at a human-equivalent dose of 30 mg/kg p.o. to adult Sprague Dawley rats caused trabecular osteopenia and suppressed the formation of mineralized nodule by bone marrow stromal cells. Moreover, DSF diminished bone regeneration at the fracture site. In growing rats, DSF diminished growth plate height, primary and secondary spongiosa, mineralized osteoid and trabecular strength. Substantial decreased bone formation was also observed in the cortical site of these rats. We conclude that DSF has a strong osteopenia inducing effect by impairing osteoblast survival and differentiation due to the inhibition of ALDH2 function. PMID:24496638

  10. Kinetics and Isotope Patterns of Ethanol and Acetaldehyde Emissions from Yeast Fermentations of Glucose and Glucose-6,6-d2 Using Selected Ion Flow Tube Mass Spectrometry: A Case Study

    Smith, D.; Wang, T.; Španěl, Patrik

    2002-01-01

    Roč. 16, č. 1 (2002), s. 69-76. ISSN 0951-4198 R&D Projects: GA ČR GA203/00/0632 Institutional research plan: CEZ:AV0Z4040901 Keywords : selected ion flow tube mass spectrometry * stable isotope * yeast fermentation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.372, year: 2002

  11. Reaction of the oximes of aliphatic aldehydes and ketones with alkoxyethenes

    In the reaction of acetone oxime with alkyl vinyl ethers in the presence of zinc chloride variable amounts of acetone 0,0'-(2-propylidene)dioxime, acetaldehyde dialkyl acetal, acetaldehyde 0-(1-alkoxyethyl)oxide, and acetone 0-(1-alkoxy-1-methylethyl)oxime, depending on the reaction conditions, are formed in addition to acetone 0-(1-alkoxyethyl)oxime (the initial addition product). In the reaction of acetaldehyde oxime with alkyl vinyl ethers in the presence of zinc chloride acetaldehyde oxime with alkyl vinyl ethers in the presence of zinc chloride acetaldehyde dialkyl acetal was isolated in addition to acetaldehyde 0-(1-alkoxyethyl)oxime. A mechanism for the formation of the obtained compounds is proposed

  12. Sequence Classification: 390200 [

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|31794711|ref|NP_857204.1| PROBABLE ACETA...LDEHYDE DEHYDROGENASE (ACETALDEHYDE DEHYDROGENASE || http://www.ncbi.nlm.nih.gov/protein/31794711 ...

  13. Sequence Classification: 399976 [

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15610671|ref|NP_218052.1| PROBABLE ACETA...LDEHYDE DEHYDROGENASE (ACETALDEHYDE DEHYDROGENASE || http://www.ncbi.nlm.nih.gov/protein/15610671 ...

  14. Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate

    Jørgensen, Betina; Christiansen, Sofie Egholm; Thomsen, M.L.D.;

    2007-01-01

    oxygen-assisted) dehydrogenation of ethanol to produce acetaldehyde. It also is concluded that most of the CO2 formed as a byproduct in the reaction results from the absorbed intermediate in the dehydrogenation of ethanol to produce acetaldehyde. By varying the amount of water in the reaction mixture...

  15. Transport of trace contaminants through porous media

    Madey, R.

    1975-01-01

    Research accomplishments in the following areas are discussed: (1) the calibration of the gas chromatograph for acetaldehyde and ethanol; (2) the development of data reduction and analysis methods; (3) the generation and analysis of experimental data for the transport of 100 ppm acetaldehyde through a cylindrical bed packed with activated carbon granules; (4) the generation and analysis of experimental data for the transport of 100 ppm ethanol through a cylindrical bed packed with activated carbon granules; and (5) a comparison of the volume adsorption capacity of activated carbon for 100 ppm concentrations of acetaldehyde, ethanol, and acetone. Activities in progress and planned activities are reviewed.

  16. Kinetics of acetic acid synthesis from ethanol over a Cu/SiO2 catalyst

    Voss, Bodil; Schjødt, Niels Christian; Grunwaldt, Jan-Dierk;

    2011-01-01

    The dehydrogenation of ethanol via acetaldehyde for the synthesis of acetic acid over a Cu based catalyst in a new process is reported. Specifically, we have studied a Cu on SiO2 catalyst which has shown very high selectivity to acetic acid via acetaldehyde compared to competing condensation routes....... The dehydrogenation experiments were carried out in a flow through lab scale tubular reactor. Based on 71 data sets a power law kinetic expression has been derived for the description of the dehydrogenation of acetaldehyde to acetic acid. The apparent reaction order was 0.89 with respect to water and...

  17. Electrocatalytic Activity of Pt/C Electrodes for Ethanol Oxidation in Vapor Phase

    LIANG Hong; YE Dai-qi; LIN Wei-ming

    2005-01-01

    High performance platinized-carbon electrodes have been developed for the electrocatalytic oxidation of ethanol to acetaldehyde in electrogenerative processes. A load current density of the electrode can be achieved as high as 600 mA per square centimeter for oxygen reducing in 3 mol/L sulfuric acid with a good stability. With these electrodes and sulfuric acid as an electrolyte in fuel cells, ethanol vapor carried by nitrogen gas can be oxidized selectively to acetaldehyde. Selectivity of acetaldehyde depends on the potential of the cell and the feed rate of ethanol vapor and it can be more than 80% under optimized conditions. The initial product of ethanol oxidized on a platinized-carbon electrode is acetaldehyde and the ethanol oxidation mechanism is discussed.

  18. 21 CFR 172.712 - 1,3-Butylene glycol.

    2010-04-01

    ...: (a) It is prepared by the aldol condensation of acetaldehyde followed by catalytic hydrogenation. (b... reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the Office...

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

    Anderson, J.A. (Oklahoma State Univ., Stillwater, OK (United States). 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.

  20. The mechanism for the rhodium-catalyzed decarbonylation of aldehydes: A combined experimental and theoretical study

    Fristrup, Peter; Kreis, Michael; Palmelund, Anders; Norrby, Per-Ola; Madsen, Robert

    2008-01-01

    The mechanism for the rhodium-catalyzed decarbonylation of aldehydes was investigated by experimental techniques (Hammett studies and kinetic isotope effects) and extended by a computational study (DFT calculations). For both benzaldehyde and phenyl acetaldehyde derivatives, linear Hammett plots...

  1. Effects of 20 Selected Fruits on Ethanol Metabolism: Potential Health Benefits and Harmful Impacts

    Zhang, Yu-Jie; Wang, Fang; Zhou, Yue; Li, Ya; Zhou, Tong; Zheng, Jie; Zhang, Jiao-jiao; Li, Sha; Xu, Dong-Ping; Li, Hua-Bin

    2016-01-01

    The consumption of alcohol is often accompanied by other foods, such as fruits and vegetables. This study is aimed to investigate the effects of 20 selected fruits on ethanol metabolism to find out their potential health benefits and harmful impacts. The effects of the fruits on ethanol metabolism were characterized by the concentrations of ethanol and acetaldehyde in blood, as well as activities of alcohol dehydrogenase and acetaldehyde dehydrogenase in liver of mice. Furthermore, potential ...

  2. Genetic Changes To Optimize Carbon Partitioning between Ethanol and Biosynthesis in Ethanologenic Escherichia coli†

    Underwood, S. A.; Zhou, S; Causey, T. B.; Yomano, L. P.; Shanmugam, K T; Ingram, L O

    2002-01-01

    The production of ethanol from xylose by ethanologenic Escherichia coli strain KO11 was improved by adding various medium supplements (acetate, pyruvate, and acetaldehyde) that prolonged the growth phase by increasing cell yield and volumetric productivity (approximately twofold). Although added pyruvate and acetaldehyde were rapidly metabolized, the benefit of these additives continued throughout fermentation. Both additives increased the levels of extracellular acetate through different mec...

  3. Ethanol-induced oxidative stress: basic knowledge

    Comporti, Mario; Signorini, Cinzia; Leoncini, Silvia; Gardi, Concetta; Ciccoli, Lucia; Giardini, Anna; Vecchio, Daniela; Arezzini, Beatrice

    2009-01-01

    After a general introduction, the main pathways of ethanol metabolism (alcohol dehydrogenase, catalase, coupling of catalase with NADPH oxidase and microsomal ethanol-oxidizing system) are shortly reviewed. The cytochrome P450 isoform (CYP2E1) specifically involved in ethanol oxidation is discussed. The acetaldehyde metabolism and the shift of the NAD/NADH ratio in the cellular environment (reductive stress) are stressed. The toxic effects of acetaldehyde are mentioned. The ethanol-induced ox...

  4. The Products of the Thermal Decomposition of CH3CHO

    Vasiliou, AnGayle

    2011-01-01

    We have used a heated 2 cm x 1 mm SiC microtubular (mu tubular) reactor to decompose acetaldehyde: CH3CHO + DELTA --> products. Thermal decomposition is followed at pressures of 75 - 150 Torr and at temperatures up to 1700 K, conditions that correspond to residence times of roughly 50 - 100 mu sec in the mu tubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: VUV photoionization mass spectroscopy (PIMS) and infrared (IR) absorption spectroscop...

  5. Quantitative DEMS study of ethanol oxidation: effect of surface structure and Sn surface modification.

    Mostafa, Ehab; Abd-El-Latif, Abd-El-Aziz A; Ilsley, Richard; Attard, Gary; Baltruschat, Helmut

    2012-12-14

    Using the dual thin layer flow through cell, a semi-quantitative analysis of the volatile products during the electrooxidation of adsorbed and bulk solution of 0.01 M ethanol at polycrystalline platinum, smooth, roughened and Sn modified Pt(11,1,1), Pt(311) electrodes has been done by on-line differential electrochemical mass spectroscopy (DEMS). In addition to the current efficiency of CO(2), that of acetaldehyde was determined as a function of the flow rate. At polycrystalline platinum, ethanol oxidation produces only acetaldehyde; the amount of acetaldehyde further oxidized to acetic acid is negligible due to convection conditions. For comparison and for calibration purposes, i-propanol oxidation was examined for which acetone is the only oxidation product. At Pt(11,1,1), the main oxidation product is acetaldehyde. At Pt(311), in addition to acetaldehyde, acetic acid was also formed. Surface modification with Sn did not increase the reactivity of Pt(11,1,1) instead it led to inhibition of the ethanol oxidation. In the case of Pt(311), the onset potential of oxidation was shifted negatively by 0.2 V in the presence of Sn. The results of the potentiostatic measurements showed that this shift is not associated with the production of CO(2); rather acetic acid and acetaldehyde are the main oxidation products. PMID:23108295

  6. Hypothesis of demodicidosis rosacea flushing etiopathogenesis.

    Robledo, Mary Ann; Orduz, Mariana

    2015-04-01

    Most of the patients with erythematotelangiectatic rosacea are characterized by flushing, oedema and telangiectasia. The etiopathogenesis of the flushing in rosacea patients is unknown. Clinically the flushing in rosacea is similar to the "Asian flushing syndrome". Most Asians have an overactive alcohol dehydrogenase (ADH) that tends to break down alcohol into acetaldehyde faster. People with "Asians flushing syndrome" have a genetic disorder with the Aldehyde Dehydrogenase 2(∗)2 (ALDH2(∗)2) allele. This is the reason why they do not metabolize very well the acetaldehyde that comes from the alcohol, which means that acetaldehyde takes much longer to clear from their blood. ALDH2 enzyme is primarily responsible for oxidation of acetaldehyde derived from ethanol metabolism, as well as oxidation of various other endogenous and exogenous aldehydes. Acetaldehyde produces the vasodilatation in the "Asian flushing syndrome". The antibodies against the GroEl chaperonin protein, a 62-kDa heat shock protein were found in the Bacillus oleronius isolated from Demodex mites, in rosacea patients. The GroEl chaperonin protein is a protein that plays a key role in normal folding of ALDH2. If the GroEl chaperonin antibodies found in patients with rosacea, cross react with the human GroEl chaperonin protein, they will not fold normally the ALDH2, and then the enzyme will not metabolize the acetaldehyde. Many of the patients with rosacea have a concomitant infection with Helicobacter pylori in their stomach. The H.pylori produces high amounts of acetaldehyde, which comes from their metabolism of ethanol or carbohydrates. As a result, high amounts of acetaldehyde will circulate for longer time in the blood, until the liver CYP2E1(p450) enzyme system finally metabilizes the acetaldehyde, during that period of time the patients will experience a flushing as well as the people with the "Asian flushing syndrome" suffer when they drink ethanol. To prove the hypothesis it is necessary

  7. Fancd2 counteracts the toxic effects of naturally produced aldehydes in mice.

    Langevin, Frédéric; Crossan, Gerry P; Rosado, Ivan V; Arends, Mark J; Patel, Ketan J

    2011-07-01

    Reactive aldehydes are common carcinogens. They are also by-products of several metabolic pathways and, without enzymatic catabolism, may accumulate and cause DNA damage. Ethanol, which is metabolised to acetaldehyde, is both carcinogenic and teratogenic in humans. Here we find that the Fanconi anaemia DNA repair pathway counteracts acetaldehyde-induced genotoxicity in mice. Our results show that the acetaldehyde-catabolising enzyme Aldh2 is essential for the development of Fancd2(-/-) embryos. Nevertheless, acetaldehyde-catabolism-competent mothers (Aldh2(+/-)) can support the development of double-mutant (Aldh2(-/-)Fancd2(-/-)) mice. However, these embryos are unusually sensitive to ethanol exposure in utero, and ethanol consumption by postnatal double-deficient mice rapidly precipitates bone marrow failure. Lastly, Aldh2(-/-)Fancd2(-/-) mice spontaneously develop acute leukaemia. Acetaldehyde-mediated DNA damage may critically contribute to the genesis of fetal alcohol syndrome in fetuses, as well as to abnormal development, haematopoietic failure and cancer predisposition in Fanconi anaemia patients. PMID:21734703

  8. Evidence for the formation of an enamine species during aldol and Michael-type addition reactions promiscuously catalyzed by 4-oxalocrotonate tautomerase.

    Poddar, Harshwardhan; Rahimi, Mehran; Geertsema, Edzard M; Thunnissen, Andy-Mark W H; Poelarends, Gerrit J

    2015-03-23

    The enzyme 4-oxalocrotonate tautomerase (4-OT), which has a catalytic N-terminal proline residue (Pro1), can promiscuously catalyze various carbon-carbon bond-forming reactions, including aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde, and Michael-type addition of acetaldehyde to a wide variety of nitroalkenes to yield valuable γ-nitroaldehydes. To gain insight into how 4-OT catalyzes these unnatural reactions, we carried out exchange studies in D2 O, and X-ray crystallography studies. The former established that H-D exchange within acetaldehyde is catalyzed by 4-OT and that the Pro1 residue is crucial for this activity. The latter showed that Pro1 of 4-OT had reacted with acetaldehyde to give an enamine species. These results provide evidence of the mechanism of the 4-OT-catalyzed aldol and Michael-type addition reactions in which acetaldehyde is activated for nucleophilic addition by Pro1-dependent formation of an enamine intermediate. PMID:25728471

  9. Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

    Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

    1999-01-01

    There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

  10. Conversion of Biomass-Derived Small Oxygenates over HZSM-5 and its Deactivation Mechanism

    Ramasamy, Karthikeyan K.; Gerber, Mark A.; Flake, Matthew D.; Zhang, He; Wang, Yong

    2014-02-28

    HZSM-5 catalyst deactivation was studied using aqueous feed mixtures containing ethanol, ethanol+ acetic acid, ethanol+ethyl acetate, or ethanol+acetaldehyde in a fixed bed reactor at 360°C and 300psig. Compared to ethanol alone experiment, addition of other oxygenates reduced catalyst life in the order of: ethyl acetateacetaldehyde. Based on the liquid product and the spent catalyst analyses from the individual ethanol, acetaldehyde, acetic acid, and ethyl acetate feed, the presence of acetaldehyde appears to produce high molecular weight aromatic compounds which deactivate the catalyst through a pore-blocking mechanism. Acetic acid deactivates the catalyst through an active site poisoning mechanism or strong adsorption of acetate intermediates on the active sites (hydroxyl groups). Ethanol deactivates the catalyst primarily through its pore-blocking mechanism, but the rate of ethanol deactivation is orders of magnitude slower than that of acetaldehyde. Ethyl acetate hydrolyzes to form acetic acid and ethanol which deactivate the catalyst through its respective mechanisms. In addition, each functional group of oxygenates requires different active sites/catalysts and different operating conditions due to competitive adsorptions on active sites for their conversion to the desired products. Therefore, it is necessary to pre-treat the mixture of oxygenates to produce a feed stream containing the same or similar functional group compounds before converting the feed stream to hydrocarbon compounds over HZSM-5 catalyst.

  11. Analysis of reactive aldehydes formed from the irradiated skin lipid, triolein

    One of the major skin lipids, triolein, was irradiated by 300 nm uv light under conditions approximately those at the skin surface exposed to sunlight for different periods of time. Irradiated samples were analyzed for acrolein, formaldehyde, and acetaldehyde by gas chromatography. Acrolein formed was derivatized to more stable 1-methyl-2-pyrazoline with N-methylhydrazine and analyzed by a nitrogen-phosphorus specific detector. Formaldehyde and acetaldehyde formed were reacted with cysteamine to give thiazolidine and 2-methylthiazolidine, respectively and analyzed by a flame photometric sulfur specific detector. The maximum amount of acrolein (1.05 nmol/mg triolein) was formed after 6 hr irradiation. The maximum quantities of formaldehyde (6 nmol/mg triolein) and acetaldehyde (2.71 nmol/mg triolein) were formed after 12 hr irradiation. Both formaldehyde and acrolein have been known to cause skin irritation in the levels of 1 ppM

  12. Computational fluid dynamics simulation of ethanol steam reforming in catalytic wall microchannels

    Uriz, I.; Arzamendi, G.; López, E.; Llorca Piqué, Jordi; Gandía, L.M.

    2011-01-01

    A three-dimensional computational fluid dynamics (CFD) simulation study of the ethanol steam reforming (ESR) in microreactors with square channels has been carried out. A phenomenological kinetic model describing the ESR on a Co3O4–ZnO catalyst has been established and implemented in the CFD codes. This model includes the ethanol dehydrogenation to acetaldehyde, ethanol decomposition to CO and CH4, acetaldehyde steam reforming to H2 and CO2 and water–gas shift as the reactions des...

  13. Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

    Baggetto, L G; Lehninger, A L

    1987-05-29

    Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented. PMID:3593337

  14. Cellulosic ethanol production via consolidated bioprocessing at 75 °C by engineered Caldicellulosiruptor bescii

    Chung, Daehwan; Cha, Minseok; Snyder, Elise N.; Elkins, James G.; Guss, Adam M.; Westpheling, Janet

    2015-01-01

    Background The C. bescii genome does not encode an acetaldehyde/alcohol dehydrogenase or an acetaldehyde dehydrogenase and no ethanol production is detected in this strain. The recent introduction of an NADH-dependent AdhE from C. thermocellum (Fig. 1a) in an ldh mutant of this strain resulted in production of ethanol from un-pretreated switchgrass, but the thermolability of the C. thermocellum AdhE at the optimum growth temperature of C. bescii (78 °C) meant that ethanol was not produced abo...

  15. Dynamic modeling of a three-stage low-temperature ethanol reformer for fuel cell application

    Garcia, Vanesa M.; Serra, Maria [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo; Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2009-07-01

    A low-temperature ethanol reformer based on a cobalt catalyst for the production of hydrogen has been designed aiming the feed of a fuel cell for an autonomous low-scale power production unit. The reformer comprises three stages: ethanol dehydrogenation to acetaldehyde and hydrogen over SnO{sub 2} followed by acetaldehyde steam reforming over Co(Fe)/ZnO catalyst and water gas shift reaction. Kinetic data have been obtained under different experimental conditions and a dynamic model has been developed for a tubular reformer loaded with catalytic monoliths for the production of the hydrogen required to feed a 1 kW PEMFC. (author)

  16. Aldehyde dehydrogenase 2 (ALDH2) and glutathione S-transferase M1 (GSTM1) polymorphisms in relation to oral cancer risk among Malaysians

    Karen-Ng, L. P.; Ghani, W. M. N.; Vimmitra, A.; Yuen, K. M.; Tan, H S; Lim, S. J.; Abraham, M. T.; Rahman, Z. A. A.; Tay, K. K.; Mustafa, W. M. W.; Jalil, N; Norlida, A.; Cheong, S. C.; Zain, R. B.

    2011-01-01

    Introduction: ALDH2 is an enzyme involved in major oxidative pathway of alcohol metabolism while GSTM1 is a drug-metabolizing enzyme of acetaldehyde. It has been reported that the mutant ALDH2 allele and the absence of GSTM1 contributes to increased oral cancer risk due to reduced acetaldehyde metabolism. This study aims to determine ALDH2 and GSTM1 polymorphisms and its association with oral cancer risk. Method: An unmatched case-control study was conducted using 163 oral cancer patients and...

  17. Dynamic Aspects of Alcoholic Fermentation of Rice Seedlings in Response to Anaerobiosis and to Complete Submergence: Relationship to Submergence Tolerance

    BOAMFA, E. I.; RAM, P. C.; Jackson, M B; Reuss, J.; Harren, F.J.M.

    2003-01-01

    Rice plants are severely damaged by complete submergence. This is a problem in rice farming and could be the result, in part, of tissue anoxia imposed by a reduced availability of oxygen. To investigate this possibility we monitored alcoholic fermentation products as markers for tissue anaerobiosis using sensitive laser‐based spectroscopy able to sense ethanol and acetaldehyde down to 3 nl l–1 and 0·1 nl l–1, respectively. Acetaldehyde emission began within 0·5 h of imposing an oxygen‐free ga...

  18. Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States

    R. Sommariva

    2008-06-01

    Full Text Available Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM. The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40–60% for all species, except acetic acid.

    The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24–28% and i-propanol (<15% and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK is mostly produced from the oxidation of n-butane (20–30% and 3-methylpentane (<40%. Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6–23% and 5–25% of acetaldehyde photochemical formation. The results highlight the importance of long-chain alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

  19. Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States

    R. Sommariva

    2011-07-01

    Full Text Available Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM. The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40–60 % for all species, except acetic acid.

    The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24–28 % and i-propanol (<15 % and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK is mostly produced from the oxidation of n-butane (20–30 % and 3-methylpentane (<40 %. Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6–23 % and 5–25 % of acetaldehyde photochemical formation. The results highlight the importance of alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

  20. Principal component analysis of UV-VIS-NIR transmission spectra of Moldavian matured wine distillates

    Khodasevich, Mikhail A.; Trofimova, Darya V.; Nezalzova, Elena I.

    2011-02-01

    Principal component analysis of UV-VIS-NIR transmission spectra of matured wine distillates (1-40 years aged) produced by three Moldavian manufacturers allows to characterize with sufficient certainty the eleven chemical parameters of considered alcoholic beverages: contents of acetaldehyde, ethyl acetate, furfural, vanillin, syringic aldehyde and acid, etc.

  1. Reaction of tobacco smoke aldehydes with human hemoglobin.

    Hoberman, H D; San George, R C

    1988-01-01

    Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and acrolein, all of which are constituents of tobacco smoke, were reacted in 5 mM concentration with the purified major fraction of normal adult human hemoglobin (hemoglobin Ao) in 1 mM concentration. A cigarette smoke condensate, diluted to contain 5 mM total aldehydes, was also reacted with 1 mM hemoglobin Ao. Cationic exchange high-performance liquid chromatography (HPLC) showed that the products formed from simple aliphatic aldehydes, with the exception of formaldehyde, were analogues of those formed from acetaldehyde, earlier shown by us to be imidazolidinone derivatives, that is, cyclic addition products of the N-terminal aminoamide function of alpha and beta chains. Formaldehyde and acrolein produced a heterogeneous mixture of derivatives including cross-linked hemoglobin dimers. The greater proportion of modified hemoglobins produced by condensate aldehydes resembled those formed from acetaldehyde, the most abundant aldehyde in the condensate. A smaller fraction consisted of cross-linked hemoglobin dimers, presumably due to the action of formaldehyde. Mass spectrometric and HPLC analyses of the 2,4-dinitrophenylhydrazones precipitated from the condensate documented the presence of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, furfural, and methylfurfural. The toxicity of aldehydes is briefly discussed in the context of the findings of this study. PMID:3236330

  2. 40 CFR Table 7 to Subpart Vvvvvv... - Partially Soluble HAP

    2010-07-01

    ...-Dichlorobenzene 106467 11. 2-Nitropropane 79469 12. 4-Methyl-2-pentanone (MIBK) 108101 13. Acetaldehyde 75070 14...-Trichloroethane (methyl chloroform) 71556 2. 1,1,2,2-Tetrachloroethane 79345 3. 1,1,2-Trichloroethane 79005 4. 1,1-Dichloroethylene (vinylidene chloride) 75354 5. 1,2-Dibromoethane 106934 6. 1,2-Dichloroethane......

  3. 75 FR 8575 - Testing of Certain High Production Volume Chemicals; Third Group of Chemicals

    2010-02-25

    ...). Method B (ASTM E 1147-92(2005)--liquid chromatography) (Ref. 20). Method C (40 CFR 799.6756--generator... Method B: ASTM E or C. 1147-92(2005) log Kow range > 4- (liquid 6: Method B or C. chromatography). log... substances, benzene, 1,2-dimethyl-3-nitro-acetaldehyde (CAS No. 83-41-0); tar oils, coal (CAS No....

  4. Guide On Analysis Of Dangerous And Harmful Object

    This book lists the dangerous and harmful object, which are Acetaldehyde, Acetic acid, Acetone, Acrolein, Aldrin Ammonia, Arsenic, Asphalt, Barium, Benzene, Benzyl chloride, Butane, Butylamine, Butyl mercaptan, Cadmium, Cadmium chloride, Cadmium nitrate, Cadmium sulfate, Calcium, Calcium carbonate, Calcium chloride, Calcium cyanamide, Calcium oxide, Captan, Carbon black, Carbon dioxide, Carbon disulfide, Catechol, Chlordane, Chlorine, Chlorine dioxide, Chlorine trifluoride and Chloroacetic acid.

  5. Sequence Classification: 891284 [

    Full Text Available TMB Non-TMH Non-TMB TMB Non-TMB TMB >gi|6321524|ref|NP_011601.1| Minor isoform of pyruvate decar ... ruvate to acetaldehyde, regulation is glucose- and ethanol -dependent, involved in amino acid catabolism; Pdc6 ...

  6. Methanol as fuel: evaluation of atmosphere contamination

    With the beginning of methanol use as automotive fuel in Sao Paulo city, 1990, were realized special measurements of methanol, formaldehyde, ethanol and acetaldehyde in atmosphere. Other indicators of air quality as carbon and ozone monoxide were also observed in this study. (C.M.)

  7. Gas-Phase Oxidation of Aqueous Ethanol by Nanoparticle Vanadia/Anatase Catalysts

    Jørgensen, Betina; Kristensen, Steffen Buus; Kunov-Kruse, Andreas Jonas;

    2009-01-01

    The gas-phase oxidation of aqueous ethanol with dioxygen has been examined with a new nanoparticle V2O5/TiO2 catalyst. Product selectivity could to a large extent be controlled by small alterations of reaction parameters, allowing production of acetaldehyde at a selectivity higher than 90%, near ...

  8. (S)-1-[(S)-4-Benzyl-2-thioxothia­zolidin-3-yl]-3-hydroxy­butan-1-one

    Jian-hong Yang; Cui-fen Lu; Zu-xing Chen; Gui-chun Yang

    2007-01-01

    The title compound, C14H17NO2S2, was synthesized by asymmetric aldol condensation of N-acylthiazolidinethione with acetaldehyde. In the molecule, the thiazolidine five-membered ring assumes an envelope conformation. Intermolecular C—H...O and intramolecular O—H...O and C—H...S hydrogen bonding helps to stabilize the structure.

  9. (S-1-[(S-4-Benzyl-2-thioxothiazolidin-3-yl]-3-hydroxybutan-1-one

    Jian-hong Yang

    2008-01-01

    Full Text Available The title compound, C14H17NO2S2, was synthesized by asymmetric aldol condensation of N-acylthiazolidinethione with acetaldehyde. In the molecule, the thiazolidine five-membered ring assumes an envelope conformation. Intermolecular C—H...O and intramolecular O—H...O and C—H...S hydrogen bonding helps to stabilize the structure.

  10. Asymmetric catalytic synthesis of the proposed structure of trocheliophorolide B

    Trost, Barry M.; Quintard, Adrien

    2012-01-01

    A concise catalytic asymmetric synthesis of the proposed structure of Trocheliophorolide B is reported. The synthetic sequence notably features an asymmetric acetaldehyde alkynylation, Ru-catalyzed alder-ene reaction and Zn-ProPhenol ynone aldol condensation. Comparison with the reported data suggests a miss-assignment of the natural product structure.

  11. Evidence for the Formation of an Enamine Species during Aldol and Michael-type Addition Reactions Promiscuously Catalyzed by 4-Oxalocrotonate Tautomerase

    Poddar, Harshwardhan; Rahimi, Mehran; Geertsema, Edzard; Thunnissen, Andy; Poelarends, Gerrit

    2015-01-01

    The enzyme 4-oxalocrotonate tautomerase (4-OT), which has a catalytic N-terminal proline residue (Pro1), can promiscuously catalyze various carbon–carbon bond-forming reactions, including aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde, and Michael-type addition of aceta

  12. One-pot synthesis of quinaldine derivatives by using microwave irradiation without any solvent - A green chemistry approach

    Javad Safari; Sayed Hossein Banitaba; Sepehr Sadegh Samiei

    2009-07-01

    A convenient and efficient procedure for synthesis of quinaldine derivatives has been developed by a simple one-pot reaction of aniline derivatives and acetaldehyde on the surface of neutral alumina impregnated with hydrochloric acid under microwave irradiation without any solvent according to green chemistry.

  13. Regulated and unregulated emissions from an internal combustion engine operating on ethanol-containing fuels

    Poulopoulos, S. G.; Samaras, D. P.; Philippopoulos, C. J.

    In the present work, the effect of ethanol addition to gasoline on regulated and unregulated emissions is studied. A 4-cylinder OPEL 1.6 L internal combustion engine equipped with a hydraulic brake dynamometer was used in all the experiments. For exhaust emissions treatment a typical three-way catalyst was used. Among the various compounds detected in exhaust emissions, the following ones were monitored at engine and catalyst outlet: methane, hexane, ethylene, acetaldehyde, acetone, benzene, 1,3-butadiene, toluene, acetic acid and ethanol. Addition of ethanol in the fuel up to 10% w/w had as a result an increase in the Reid vapour pressure of the fuel, which indicates indirectly increased evaporative emissions, while carbon monoxide tailpipe emissions were decreased. For ethanol-containing fuels, acetaldehyde emissions were appreciably increased (up to 100%), especially for fuel containing 3% w/w ethanol. In contrast, aromatics emissions were decreased by ethanol addition to gasoline. Methane and ethanol were the most resistant compounds to oxidation while ethylene was the most degradable compound over the catalyst. Ethylene, methane and acetaldehyde were the main compounds present at engine exhaust while methane, acetaldehyde and ethanol were the main compounds in tailpipe emissions for ethanol fuels after the catalyst operation.

  14. Interaction between ADH1C Arg272Gln and alcohol intake in relation to breast cancer risk suggests that ethanol is the causal factor in alcohol related breast cancer

    Benzon Larsen, Signe; Vogel, Ulla Birgitte; Christensen, Jane;

    2010-01-01

    Alcohol is a risk factor for breast cancer. We wanted to determine if ADH polymorphisms which modify the rate of ethanol oxidation to acetaldehyde, were associated with breast cancer risk. We matched 809 postmenopausal breast cancer cases with 809 controls, nested within the prospective Diet...

  15. Experimental research on photocatalytic oxidation air purification technology applied to aircraft cabins

    Sun, Yuexia; Fang, Lei; Wyon, David P.;

    2005-01-01

    by oxida-tion in the PCO units tested. However, some intermediate products, such as Formaldehyde and Acetaldehyde, were detected. Physiological measurements did not show any significant effects of the two PCO units. Both positive and negative effects of using PCO units on subjec-tive assessments were...

  16. 21 CFR 184.1005 - Acetic acid.

    2010-04-01

    ... carbohydrates or by organic synthesis. The principal synthetic methods currently employed are oxidation of acetaldehyde derived from ethylene, liquid phase oxidation of butane, and reaction of carbon monoxide with..._regulations/ibr_locations.html. (c) The ingredient is used as a curing and pickling agent as defined in §...

  17. Evaluation of vinyl laurate in a battery of in vitro and in vivo tests for genotoxicity.

    van Acker, Frédérique; Messinger, Horst; Bär, Albert

    2015-06-01

    Vinyl laurate is a potential residual monomer in chewing gum base formulated with polyvinyl acetate vinyl laurate copolymer (PVAcVL). The genotoxic potential of vinyl laurate was examined in a battery of in vitro and in vivo genotoxicity tests. Vinyl laurate was not mutagenic in Ames tests. In addition, it was not mutagenic in the HPRT mutation assay in L5178Y cells. An in vitro mammalian chromosome aberration assay performed in CHO cells was equivocal. Vinyl laurate and/or its metabolites were not clastogenic in the mouse bone marrow micronucleus test. Kinetic data indicate that VL is metabolised to acetaldehyde and lauric acid. Both metabolites are well known and have been studied previously. Model calculations show, that any exposure to acetaldehyde from the consumption of PVAcVL containing chewing gum will remain far below levels of acetaldehyde exposure from food in which acetaldehyde occurs naturally. Direct exposure to VL will primarily be at the site of entry. The lack of toxicity in a 90-day repeated dose toxicity test, performed with VL doses up to approximately 3000 times higher than the maximal VL intake from the consumption of a typical piece of chewing gum, demonstrates a high safety margin. PMID:25445001

  18. 46 CFR 154.1720 - Indirect refrigeration.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression....

  19. Mass balance evaluation of alcohol emission from cattle feed

    Silage on dairy farms has been recognized as an important source of volatile organic compounds (VOCs) to the atmosphere, and therefore a contributor to tropospheric ozone. Considering reactivity and likely emission rates, ethanol, 1-propanol, and acetaldehyde probably make the largest contribution t...

  20. 77 FR 20817 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    2012-04-06

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... literature searches for IRIS assessments; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of literature searches for acetaldehyde (75-07-0) and...

  1. 40 CFR 60.707 - Chemicals affected by subpart RRR.

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Chemicals affected by subpart RRR. 60.707 Section 60.707 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS....707 Chemicals affected by subpart RRR. Chemical CAS No. 1 Acetaldehyde 75-07-0 Acetic acid...

  2. Contribution of carbonyl photochemistry to aging of atmospheric secondary organic aerosol

    Mang, Stephen A.; Henricksen, Dana K.; Bateman, Adam P.;

    2008-01-01

    in situ by infrared cavity ring-down spectroscopy. A number of additional gas-phase products of SOA photodegradation were observed by gas chromatography, including methane, ethene, acetaldehyde, acetone, methanol, and I-butene. The absorption spectrum of SOA material collected onto CaF, windows was...

  3. Atmospheric ethanol in London and the potential impacts of future fuel formulations.

    Dunmore, Rachel E; Whalley, Lisa K; Sherwen, Tomás; Evans, Mathew J; Heard, Dwayne E; Hopkins, James R; Lee, James D; Lewis, Alastair C; Lidster, Richard T; Rickard, Andrew R; Hamilton, Jacqueline F

    2016-07-18

    There is growing global consumption of non-fossil fuels such as ethanol made from renewable biomass. Previous studies have shown that one of the main air quality disadvantages of using ethanol blended fuels is a significant increase in the production of acetaldehyde, an unregulated and toxic pollutant. Most studies on the impacts of ethanol blended gasoline have been carried out in the US and Brazil, with much less focus on the UK and Europe. We report time resolved measurements of ethanol in London during the winter and summer of 2012. In both seasons the mean mixing ratio of ethanol was around 5 ppb, with maximum values over 30 ppb, making ethanol currently the most abundant VOC in London air. We identify a road transport related source, with 'rush-hour' peaks observed. Ethanol is strongly correlated with other road transport-related emissions, such as small aromatics and light alkanes, and has no relationship to summer biogenic emissions. To determine the impact of road transport-related ethanol emission on secondary species (i.e. acetaldehyde and ozone), we use both a chemically detailed box model (incorporating the Master Chemical Mechanism, MCM) and a global and nested regional scale chemical transport model (GEOS-Chem), on various processing time scales. Using the MCM model, only 16% of the modelled acetaldehyde was formed from ethanol oxidation. However, the model significantly underpredicts the total levels of acetaldehyde, indicating a missing primary emission source, that appears to be traffic-related. Further support for a primary emission source comes from the regional scale model simulations, where the observed concentrations of ethanol and acetaldehyde can only be reconciled with the inclusion of large primary emissions. Although only constrained by one set of observations, the regional modelling suggests a European ethanol source similar in magnitude to that of ethane (∼60 Gg per year) and greater than that of acetaldehyde (∼10 Gg per year). The

  4. Red ginseng relieves the effects of alcohol consumption and hangover symptoms in healthy men: a randomized crossover study.

    Lee, Mi-Hyang; Kwak, Jung Hyun; Jeon, Gayoung; Lee, Jong-Won; Seo, Jang-Ho; Lee, Hoon-Sang; Lee, Jong Ho

    2014-03-01

    Heavy drinking causes hangover symptoms, because the action of alcohol dehydrogenase forms acetaldehyde, which is metabolized by acetaldehyde dehydrogenase into acetate. Red ginseng shows positive effects on alcohol metabolism in animal studies. We investigated the effects of red ginseng on relieving alcohol and hangover symptoms in 25 healthy men in a randomized crossover study. At each visit (0, 1, and 2 weeks), the subjects drank 100 mL whiskey (40% alcohol) and either 100 mL water or 100 mL of a 0.321 mg mL(-1) red ginseng anti-hangover drink (RGD). We took blood samples periodically until 240 min after alcohol consumption, and we investigated the blood profiles, alcohol levels, and acetaldehyde levels. We also measured anthropometric parameters, expiratory air-alcohol levels, and hangover symptoms. The plasma alcohol concentrations within the RGD group were significantly lower than those within the placebo group after 30 min (p = 0.002), 45 min (p = 0.016), and 60 min (p = 0.009); the areas under the response curves revealed a positive effect of RGD (p = 0.051). Furthermore, the expiratory alcohol concentration was significantly lower after 30 min (p = 0.005) and 60 min (p = 0.065), and the areas under the response curves (p = 0.058) likewise revealed a positive effect of RGD. The plasma acetaldehyde level was significantly elevated at 120 min (p = 0.020), but the areas under the response curves showed a similar trend (p = 0.054). While the plasma acetaldehyde concentration slightly increased, the RGD showed positive effects on hangover symptoms. Considering the reduction of plasma alcohol levels, expiratory concentrations, and hangover severity, we conclude that red ginseng relieves the symptoms of alcohol hangover. PMID:24458173

  5. Flooding effects on plant physiology and VOC emissions from Amazonian tree species from two different flooding environments: Varzea and Igapo

    Bracho Nunez, A.; Knothe, N.; Liberato, M. A. R.; Schebeske, G.; Ciccioli, P.; Piedade, M. T. F.; Kesselmeier, J.

    2009-04-01

    A land area of 300.000 km² in the Amazon basin is subjected to a continuous flooding pulse, being flooded for 210 days a-1 on an average (Junk et al. 1993). To survive the flooding period vegetation has developed several morphological, anatomical and physiological strategies to mitigate the produced stress due to root anoxia. One of the strategies is fermentation of sucrose in the roots to comply with the energy demand under anoxia. The resulting toxic metabolite ethanol is transported through the transpiration stream to the leaves and can be directly emitted into the atmosphere or converted to acetaldehyde and/or acetate, still volatile enough to be partly released. We investigated short-term and long-term flooding effects on physiology and VOC emission by plant species from várzea and igapó and observed ethanol and acetaldehyde emissions from the várzea species Vatairea guianensis after one day of flooding, which decreased considerably within the next three days. The same species from igapó showed no acetaldehyde emission and much lower emission rates of ethanol, than the várzea species. In contrast Hevea spruceana from both várzea and igapó showed no ethanol or acetaldehyde emissions. After long term flooding (2 months) we did not find any emissions of acetaldehyde or ethanol from all plant species investigated. However, isoprene and monoterpene emissions were clearly affected, showing a significant decrease. Carbon dioxide assimilation was not affected by short term flooding, but declined after two months root anoxia in the case of Hevea spruceana.

  6. Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of selected organic compounds

    Al-Ghamdi, Saleh

    Cyclodextrin metal organic frameworks (CDMOFs) with different types of cyclodextrins (CDs) (i.e., Alpha, Beta and Gamma-CD) and coordination potassium ion sources (KOH) CDMOF-a and (C7H5KO2) CDMOF-b were synthesized and fully characterized. The physical and thermal properties of the successfully produced CDMOFs were evaluated using N2 gas sorption, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The N2 gas sorption isotherm revealed high uptake into the micropores (330 cm3.g -1 for Gamma-CDMOF-a) to macropore (125 cm3.g -1 for Gamma-CDMOF-b) structures with isotherm types I and II for Gamma-CDMOFs and Alpha-CDMOFs, respectively. The Langmuir specific surface area (SSA) of Gamma-CDMOF-a (1376 m2.g-1) was significantly higher than the SSA of Alpha-CDMOF-a (289 m2.g -1) and Beta-CDMOF-a (54 m2.g-1). The TGA of dehydrated CDMOF crystals showed the structures were thermally stable up to 300 °C. The XRD of the Gamma-CDMOFs and Alpha-CDMOFs showed a highly face-centered-cubic symmetrical structure. An Aldol condensation reaction occurred during the encapsulation of acetaldehyde, hexanal, trans-2-hexenal, and ethanol into Gamma-CDMOF-a, with a SSA of 1416 m2.g -1. However, Gamma-CDMOF-b with a SSA of 499 m2.g -1 was successfully used to encapsulate acetaldehyde. The maximum release of acetaldehyde from CDMOF-b was 53 mug of acetaldehyde per g of CDMOF, which is greater than previously reported acetaldehyde encapsulation on Beta-CD inclusion complexes.

  7. Glass fibers and vapor phase components of cigarette smoke as cofactors in experimental respiratory tract carcinogenesis

    Feron, V.J.; Kuper, C.F.; Spit, B.J.; Reuzel, P.G.; Woutersen, R.A.

    1985-01-01

    Syrian golden hamsters were given intratracheal instillations of glass fibers with or without BP suspended in saline, once a fortnight for 52 weeks; the experiment was terminated at week 85. No tumors of the respiratory tract were observed in hamsters treated with glass fibers alone. There was no indication that glass fibers enhanced the development of respiratory tract tumors induced by BP. In another study Syrian golden hamsters were exposed to fresh air or to a mixture of 4 major vapor phase components of cigarette smoke, viz. isoprene (800----700 ppm), methyl chloride (1000----900 ppm), methyl nitrite (200----190 ppm) and acetaldehyde (1400----1200 ppm) for a period of at most 23 months. Some of the animals were also given repeated intratracheal instillations of BP or norharman in saline. Laryngeal tumors were found in 7/31 male and 6/32 female hamsters exposed only to the vapor mixture, whereas no laryngeal tumors occurred in controls. The tumor response of the larynx most probably has to be ascribed entirely to the action of acetaldehyde. Simultaneous treatment with norharman or BP did not affect the tumor response of the larynx. Acetaldehyde may occur in the vapor phase of cigarette smoke at levels up to 2000 ppm. Chronic inhalation exposure of rats to acetaldehyde at levels of 0 (controls), 750, 1500 or 3000----1000 ppm resulted in a high incidence of nasal carcinomas, both squamous cell carcinomas of the respiratory epithelium and adenocarcinomas of the olfactory epithelium. It was discussed that acetaldehyde may significantly contribute to the induction of bronchogenic cancer by cigarette smoke in man.

  8. Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

    J. C. Gong

    2010-08-01

    Full Text Available Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein in a central Beijing site in the summer and early fall of 2008 (from June to October. Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions. In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5. These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

  9. Evaluation of a Combined Ultraviolet Photocatalytic Oxidation(UVPCO)/Chemisorbent Air Cleaner for Indoor Air Applications

    Hodgson, Alfred T.; Destaillats, Hugo; Hotchi, Toshifumi; Fisk,William J.

    2007-02-01

    We previously reported that gas-phase byproducts of incomplete oxidation were generated when a prototype ultraviolet photocatalytic oxidation (UVPCO) air cleaner was operated in the laboratory with indoor-relevant mixtures of VOCs at realistic concentrations. Under these conditions, there was net production of formaldehyde and acetaldehyde, two important indoor air toxicants. Here, we further explore the issue of byproduct generation. Using the same UVPCO air cleaner, we conducted experiments to identify common VOCs that lead to the production of formaldehyde and acetaldehyde and to quantify their production rates. We sought to reduce the production of formaldehyde and acetaldehyde to acceptable levels by employing different chemisorbent scrubbers downstream of the UVPCO device. Additionally, we made preliminary measurements to estimate the capacity and expected lifetime of the chemisorbent media. For most experiments, the system was operated at 680-780 m{sup 3}/h (400-460 cfm). A set of experiments was conducted with common VOCs introduced into the UVPCO device individually and in mixture. Compound conversion efficiencies and the production of formaldehyde and acetaldehyde were determined by comparison of compound concentrations upstream and downstream of the reactor. There was general agreement between compound conversions efficiencies determined individually and in the mixture. This suggests that competition among compounds for active sites on the photocatalyst surface will not limit the performance of the UVPCO device when the total VOC concentration is low. A possible exception was the very volatile alcohols, for which there were some indications of competitive adsorption. The results also showed that formaldehyde was produced from many commonly encountered VOCs, while acetaldehyde was generated by specific VOCs, particularly ethanol. The implication is that formaldehyde concentrations are likely to increase when an effective UVPCO air cleaner is used in

  10. Evaluation of volatile compounds and free fatty acids in set types yogurts made of ewes', goats' milk and their mixture using two different commercial starter cultures during refrigerated storage.

    Güler, Zehra; Gürsoy-Balcı, Alev Canan

    2011-08-01

    Six different types of yogurt were manufactured from Damascus goat milk, Awassi ewe milk and a mixture of equal portions of the 2 species of milk using 2 types of commercial yogurt cultures (CH-1 and YF-3331). Yogurts were chemically analysed at 1, 7, 14 and 21days of storage. Results showed that cultures significantly affected acetaldehyde (Pmilk significantly influenced acetaldehyde (Pmilk yogurt made with culture YF-3331, and increased during storage, while the levels of medium-chain free fatty acids, except for decanoic acid, were unchanged and the amount of long-chain free fatty acids decreased during storage. Cultures used and types of milk had no effect on long-chain free fatty acids in yogurts. PMID:25214097

  11. A coniferyl aldehyde dehydrogenase gene from Pseudomonas sp. strain HR199 enhances the conversion of coniferyl aldehyde by Saccharomyces cerevisiae.

    Adeboye, Peter Temitope; Olsson, Lisbeth; Bettiga, Maurizio

    2016-07-01

    The conversion of coniferyl aldehyde to cinnamic acids by Saccharomyces cerevisiae under aerobic growth conditions was previously observed. Bacteria such as Pseudomonas have been shown to harbor specialized enzymes for converting coniferyl aldehyde but no comparable enzymes have been identified in S. cerevisiae. CALDH from Pseudomonas was expressed in S. cerevisiae. An acetaldehyde dehydrogenase (Ald5) was also hypothesized to be actively involved in the conversion of coniferyl aldehyde under aerobic growth conditions in S. cerevisiae. In a second S. cerevisiae strain, the acetaldehyde dehydrogenase (ALD5) was deleted. A prototrophic control strain was also engineered. The engineered S. cerevisiae strains were cultivated in the presence of 1.1mM coniferyl aldehyde under aerobic condition in bioreactors. The results confirmed that expression of CALDH increased endogenous conversion of coniferyl aldehyde in S. cerevisiae and ALD5 is actively involved with the conversion of coniferyl aldehyde in S. cerevisiae. PMID:27070284

  12. Development of hierarchically porous cobalt oxide for enhanced photo-oxidation of indoor pollutants

    Porous cobalt oxide was successfully prepared by precipitation of cobalt hydroxide followed by low temperature thermal decomposition. The morphologies of the resultant oxides remained as the corresponding hydroxides, although the morphology of cobalt hydroxides was greatly influenced by the precursor salts. The cobalt oxides with average crystal size less than 20 nm were characterized by X-ray diffraction, scanning electron microscope, BET surface area, and XPS analysis. The photocatalytic activities of the various cobalt oxides morphologies were investigated by comparing the photo-degradation of acetaldehyde under simulated solar illumination. Relative to their low order structures and reference titania samples, the hierarchical nanostructures of cobalt oxide showed excellent abilities to rapidly degrade acetaldehyde, a model air pollutant. This was attributed to the unique nature of these hierarchical cobalt oxide nanoassemblies, which contained many catalytically active reaction sites and open pores

  13. Preparation and Evaluation of Transdermal Drug Delivery System of Etoricoxib Using Modified Chitosan

    Wahid, A.; Sridhar, B. K.; Shivakumar, S.

    2008-01-01

    In the present investigation chitosan has been chemically modified by treating with two different aldehydes like acetaldehyde and propionaldehyde to form Schiff’s bases. Schiff’s bases of chitosan with acetaldehyde and propionaldehyde were named as polymer A and polymer B, respectively. Fourier Transform Infra Red (FTIR) spectral data have confirmed the reaction carried out on chitosan. Drug free polymeric films of chitosan, chemically modified chitosan and chitosan/hydroxypropylmethylcellulose blend were prepared and evaluated for various physicochemical characters. Further, the films were incorporated with anti-inflammatory drug, etoricoxib using glycerol as plasticizer. The drug loaded films were cross-linked with sodium citrate and studied for permeation characteristics across dialysis membrane and rat skin. All the films were evaluated for bursting strength, swelling index, moisture uptake, thickness uniformity, drug content uniformity, tensile strength, percent elongation at break, percent flatness, water vapour transmission rate and in vitro drug permeation study. PMID:20046770

  14. Biosynthesis of l-phenylacetyl carbinol from locally isolated yeasts

    In the present study, 250 yeast strains were isolated from samples of different natural sources as cane-molasses, decaying vegetables and bagasse using glucose enriched medium. Among these, 106 strains showed no growth in acetaldehyde (1 g/l) supplemented yeast extract-peptone dextrose plates during qualitative screening. In the course of quantitative screening, 64 acetaldehyde tolerants gave almost negligible L-PAC production (=0.5 g/l) using glucose-peptone medium in shake flasks. A comparatively better L-PAC production was observed with the rest of strains. The isolate Saccharomyces cerevisiae GCU-36 exhibited higher L-PAC production (2.58 g/l). However, lower sugar consumption and subsequent biomass formation was noted. Therefore, yeast GCU-36 was selected as a hyper producer of L-PAC in batch culture. (author)

  15. Torsional symmetry dependence of S1 dynamics in molecules that under methyl internal rotation

    the single-rovibronic-level fluorescence of intermediate-case molecules that undergo methyl internal rotation is strongly influenced by the torsional symmetry of the lowest excited singlet state (S1). The most dramatic example of such symmetry dependence comes from the recent finding that the intensities of the e-e transitions in the high-resolution S1 left-arrow S0 fluorescence excitation spectra of jet-cooled acetaldehyde become very weak relative to the a-a transitions at higher beam temperatures. In this study, they rationalize this remarkable torsional symmetry dependence of electronic relaxation in acetaldehyde on the basis of internal-overall rotation coupling that leads to symmetry-selective increase in the density of states for singlet-triplet coupling. Related observations by others on aliphatic carbonyls and diazabenzenes are also discussed within the context of the coupling between the internal and overall rotation

  16. Effect of oxidoreduction potential on aroma biosynthesis by lactic acid bacteria in nonfat yogurt.

    Martin, F; Cachon, R; Pernin, K; De Coninck, J; Gervais, P; Guichard, E; Cayot, N

    2011-02-01

    The aim of this study was to investigate the effect of oxidoreduction potential (Eh) on the biosynthesis of aroma compounds by lactic acid bacteria in non-fat yogurt. The study was done with yogurts fermented by Lactobacillus bulgaricus and Streptococcus thermophilus. The Eh was modified by the application of different gaseous conditions (air, nitrogen, and nitrogen/hydrogen). Acetaldehyde, dimethyl sulfide, diacetyl, and pentane-2,3-dione, as the major endogenous odorant compounds of yogurt, were chosen as tracers for the biosynthesis of aroma compounds by lactic acid bacteria. Oxidative conditions favored the production of acetaldehyde, dimethyl sulfide, and diketones (diacetyl and pentane-2,3-dione). The Eh of the medium influences aroma production in yogurt by modifying the metabolic pathways of Lb. bulgaricus and Strep. thermophilus. The use of Eh as a control parameter during yogurt production could permit the control of aroma formation. PMID:21257030

  17. Study of the electrooxidation of ethanol on hydrophobic electrodes by DEMS and HPLC

    The electrochemical oxidation of ethanol in alkaline solution has been studied on Cu-PVC electrode and Ni/Cu-PVC composite electrodes modified by ruthenium nanoparticles. The techniques used were cyclic voltammetry (CV), steady-state potentiostatic method, on line differential electrochemical mass spectrometry (DEMS), and high-performance liquid chromatography (HPLC). The chemical products: acetaldehyde and acetic acid were detected measuring the proper mass charge (m/z) ratios. These products were also confirmed by HPLC. The surface modification of composite electrodes by ruthenium nanoparticles promotes the formation of acetaldehyde. As shown by DEMS, the surface modification shifts the onset potential for oxygen evolution reaction on the Cu-PVC composite electrode towards more anodic values

  18. A theoretical study for one-dimensional modeling for VOC in a catalytic converter

    Chauhan, S.; Sharma, L.; Srivastava, V. K.

    2010-07-01

    Modeling for catalytic oxidation of a volatile organic compound, acetaldehyde for the purpose of controlling tail-pipe emissions from vehicular exhaust was carried out. The model developed was one-dimensional unsteady state model, using mass and energy balance equations to predict results for acetaldehyde conversion in an adiabatic monolith operating under warm-up conditions. The equations consisted of a set of partial differential equations that are coupled and solved using Backward Implicit Scheme. Analysis of the behavior of the converter during warm up period was carried out and it was observed that the warm up was faster for a fresh catalyst and this warm up period could be reduced by introducing hot incoming exhaust gas at higher temperature.

  19. Recent observations of organic molecules in nearby cold, dark interstellar clouds

    Suzuki, H.; Ohishi, M.; Morimoto, M.; Kaifu, N.; Friberg, P.

    1985-01-01

    Recent investigations of the organic chemistry of relatively nearby cold, dark interstellar clouds are reported. Specifically, the presence of interstellar tricarbon monoxide (C3O) in Taurus Molecular Cloud 1 (TMC-1) is confirmed. The first detection in such regions of acetaldehyde (CH3CHO), the most complex oxygen-containing organic molecule yet found in dark clouds is reported, as well as the first astronomical detection of several molecular rotational transitions, including the J = 18-17 and 14-13 transitions of cyanodiacetylene (HC5N), the 1(01)-0(00) transition of acetaldehyde, and the J = 5-4 transition of C3O. A significant upper limit is set on the abundance of cyanocarbene (HCCN) as a result of the first reported interstellar search for this molecule.

  20. Dynamic modeling and controllability analysis of an ethanol reformer for fuel cell application

    Garcia, Vanesa M.; Serra, Maria; Riera, Jordi [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain); Planta Piloto de Ingenieria Quimica (CONICET-UNS), Camino de la Carrindanga km7, 8000 Bahia Blanca (Argentina); Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2010-09-15

    This work presents a controllability analysis of a low temperature ethanol reformer based on a cobalt catalyst for fuel cell application. The study is based on a non-linear dynamic model of a reformer which operates in three separate stages: ethanol dehydrogenation to acetaldehyde and hydrogen, acetaldehyde steam reforming, and water-gas-shift reaction. The controllability analysis is focused on the rapid dynamics due to mass balances and is based on a linearization of the complex non-linear model of the reformer. RGA, CN and MRI analysis tools are applied to the linear model suggesting that a good performance can be obtained with decentralized control for frequencies up to 0.1 rad s{sup -1}. (author)

  1. Prebiotic synthesis of histidine

    Shen, C.; Yang, L.; Miller, S. L.; Oro, J.

    1990-01-01

    The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

  2. Infrared Absorption Spectroscopy and Chemical Kinetics of Free Radicals, Final Technical Report

    Curl, Robert F.; Glass, Graham P.

    2004-11-01

    This research was directed at the detection, monitoring, and study of the chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. Work on the reaction of OH with acetaldehyde has been completed and published and work on the reaction of O({sup 1}D) with CH{sub 4} has been completed and submitted for publication. In the course of our investigation of branching ratios of the reactions of O({sup 1}D) with acetaldehyde and methane, we discovered that hot atom chemistry effects are not negligible at the gas pressures (13 Torr) initially used. Branching ratios of the reaction of O({sup 1}D) with CH{sub 4} have been measured at a tenfold higher He flow and fivefold higher pressure.

  3. Preparation and evaluation of transdermal drug delivery system of etoricoxib using modified chitosan

    Wahid A

    2008-01-01

    Full Text Available In the present investigation chitosan has been chemically modified by treating with two different aldehydes like acetaldehyde and propionaldehyde to form Schiff′s bases. Schiff′s bases of chitosan with acetaldehyde and propionaldehyde were named as polymer A and polymer B, respectively. Fourier Transform Infra Red (FTIR spectral data have confirmed the reaction carried out on chitosan. Drug free polymeric films of chitosan, chemically modified chitosan and chitosan/hydroxypropylmethylcellulose blend were prepared and evaluated for various physicochemical characters. Further, the films were incorporated with anti-inflammatory drug, etoricoxib using glycerol as plasticizer. The drug loaded films were cross-linked with sodium citrate and studied for permeation characteristics across dialysis membrane and rat skin. All the films were evaluated for bursting strength, swelling index, moisture uptake, thickness uniformity, drug content uniformity, tensile strength, percent elongation at break, percent flatness, water vapour transmission rate and in vitro drug permeation study.

  4. Declinol, a Complex Containing Kudzu, Bitter Herbs (Gentian, Tangerine Peel) and Bupleurum, Significantly Reduced Alcohol Use Disorders Identification Test (AUDIT) Scores in Moderate to Heavy Drinkers: A Pilot Study

    Kushner, Steven; HAN, DAVID; Oscar-Berman, Marlene; B. William Downs; Margaret A. Madigan; Giordano, John; Beley, Thomas; Jones, Scott; Barh, Debmayla; Simpatico, Thomas; Dushaj, Kristina; Lohmann, Raquel; Braverman, Eric R; Schoenthaler, Stephen; Ellison, David

    2013-01-01

    It is well established that inherited human aldehyde dehydrogenase 2 (ALDH-2) deficiency reduces the risk for alcoholism. Kudzu plants and extracts have been used for 1,000 years in traditional Chinese medicine to treat alcoholism. Kudzu contains daidzin, which inhibits ALDH-2 and suppresses heavy drinking in rodents. Decreased drinking due to ALDH-2 inhibition is attributed to aversive properties of acetaldehyde accumulated during alcohol consumption. However not all of the anti-alcohol prop...

  5. Tissue damage and nutritional factors in experimental respiratory tract (Co-)carcinogenesis.

    Reuzel, P G; Feron, V.J.; Spit, B J; Beems, R. B.; Kroes, R.

    1983-01-01

    Cofactors involved in respiratory tract carcinogenesis were studied in Syrian golden hamsters or in rats using benzo(a)pyrene as the carcinogenic agent. These factors included severe tissue damage induced by electro-coagulation, glass fibers administered by intratracheal instillation, acetaldehyde as irritant vapor, food restriction, and nutrients such as vitamin A and saturated and unsaturated fats. In addition, the effects of a combined exposure to four different major gaseous cigarette smo...

  6. Acetate Causes Alcohol Hangover Headache in Rats

    Maxwell, Christina R.; Rebecca Jay Spangenberg; Hoek, Jan B.; Silberstein, Stephen D.; Oshinsky, Michael L.

    2010-01-01

    BACKGROUND: The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. METHODS: We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. RESULTS: Ethanol initially decreased sensitivity to mechanical stimuli on the face (ana...

  7. Natural Products for the Prevention and Treatment of Hangover and Alcohol Use Disorder

    Fang Wang; Ya Li; Yu-Jie Zhang; Yue Zhou; Sha Li; Hua-Bin Li

    2016-01-01

    Alcoholic beverages such as beer, wine and spirits are widely consumed around the world. However, alcohol and its metabolite acetaldehyde are toxic and harmful to human beings. Chronic alcohol use disorder or occasional binge drinking can cause a wide range of health problems, such as hangover, liver damage and cancer. Some natural products such as traditional herbs, fruits, and vegetables might be potential dietary supplements or medicinal products for the prevention and treatment of the pro...

  8. Alcohol-Induced Alterations in Hepatic Microtubule Dynamics Can Be Explained by Impaired Histone Deacetylase 6 Function

    Shepard, Blythe D.; Joseph, Rohan A.; Kannarkat, George T.; Rutledge, Tara M.; Dean J. Tuma; Tuma, Pamela L.

    2008-01-01

    We have been using polarized, hepatic WIF-B cells to examine ethanol-induced liver injury. These cells polarize in culture and maintain numerous liver-specific activities including the ability to metabolize alcohol. Previously, we found that microtubules were more highly acetylated and more stable in ethanol-treated WIF-B cells and that increased microtubule acetylation required ethanol metabolism and was likely mediated by acetaldehyde. This study was aimed at identifying the mechanism respo...

  9. Serum low density lipoprotein of alcoholic patients is chemically modified in vivo and induces apolipoprotein E synthesis by macrophages.

    Lin, R C; Dai, J; Lumeng, L; Zhang, M Y

    1995-01-01

    This work was carried out to investigate the effect of alcohol drinking on serum LDL. Agarose gel electrophoresis showed that LDL samples from alcoholic patients without serious liver disease were more negatively charged and moved faster toward the cathode than LDL from nondrinking control subjects. Rabbit antibodies raised by using keyhole limpet hemocyanin modified in vitro by 4-hydroxynonenal or by acetaldehyde as immunogens reacted more strongly with patients' LDL than with control LDL, i...

  10. Soluble aldehyde dehydrogenase and metabolism of aldehydes by soybean bacteroids.

    Peterson, J. B.; LaRue, T A

    1982-01-01

    A soluble aldehyde dehydrogenase (EC 1.2.1.3) was partially purified from Rhizobium japonicum bacteroids and from free-living R. japonicum 61A76. The enzyme was activated by NAD+, NADH, and dithiothreitol, and it reduced NAD(P)+. Acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, and succinic semialdehyde were substrates. The Km for straight-chain aldehydes decreased with increasing carbon chain length. The aldehyde dehydrogenase was inhibited by 6-cyanopurine, but not by metronidazo...

  11. Effect of Lactobacillus pentosus-Fermented Artemisiae Argi Folium on Nitric Oxide Production of Macrophage impaired with Various Toxicants

    Wansu Park

    2009-01-01

    Objectives : The purpose of this study is to investigate the effect of Water Extract from Lactobacillus pentosus-fermented ARTEMISIAE ARGI FOLIUM (AFL) on nitric oxide production of mouse macrophage Raw 264.7 cells impaired by various toxicants such as gallic acid, EtOH, nicotine, acetaminophen, and acetaldehyde. Methods : ARTEMISIAE ARGI FOLIUM was fermented with Lactobacillus pentosus and extracted by water. Nitric oxide production of mouse macrophage Raw 264.7 cells was measured by Grie...

  12. MPI spectroscopy in the region of the 3p Rydberg state of some cycloketones

    Kosmidis, C.; Boulakis, G.; Bolovinos, A.; Tsekeris, P.; Brint, P.

    1992-03-01

    The two-photon resonance three photon ionization spectra of cyclopentanone, cyclohexanone and cycloheptanone in the region of the 3p Rydberg state have been recorded, analysed and compared with the one-photon absorption spectra. A new 3p origin is identified for cyclopentanone. The absence from the MPI spectra of a sharp spectral feature that is observed in the absorption spectra is discussed. Photochemical generation of acetaldehyde is observed at high laser intensities and possible mechanisms for this are considered.

  13. Effects of ADH2 Overexpression in Saccharomyces bayanus during Alcoholic Fermentation▿

    Maestre, Oscar; García-Martínez, Teresa; Peinado, Rafael A.; Mauricio, Juan C.

    2007-01-01

    The effect of overexpression of the gene ADH2 on metabolic and biological activity in Saccharomyces bayanus V5 during alcoholic fermentation has been evaluated. This gene is known to encode alcohol dehydrogenase II (ADH II). During the biological aging of sherry wines, where yeasts have to grow on ethanol owing to the absence of glucose, this isoenzyme plays a prominent role by converting the ethanol into acetaldehyde and producing NADH in the process. Overexpression of the gene ADH2 during a...

  14. The Inhibition effect of Yoghurt Starter Culture Metabolites

    ASLIM, Belma; BEYATLI, Yavuz

    2000-01-01

    In this study effect of some separate and combined metabolic compounds produced by lactic acid were tested on food pathogenic and contaminant microorgnasms. For this study, five strains of each Lactobacillus bulgaricus and Streptococcus thermophilus were used. The inhibition effects of the metabolic products (lactic acid, hydrogen peroxide, acetaldehyde, diacetyl) produced by the stains on test bacteria ( Staphylococcus aureus, Escherichia coli) were determined. Also, a random combination...

  15. Interaction of alcohol and smoking in the pathogenesis of upper digestive tract cancers - possible chemoprevention with cysteine

    Salaspuro, Ville

    2006-01-01

    Background: Alcohol consumption and smoking are the main causes of upper digestive tract cancers. These risk factors account for over 75% of all cases in developed countries. Epidemiological studies have shown that alcohol and tobacco interact in a multiplicative way to the cancer risk, but the pathogenetic mechanism behind this is poorly understood. Strong experimental and human genetic linkage data suggest that acetaldehyde is one of the major factors behind the carcinogenic effect. In the ...

  16. Nutraceutical strategies for ameliorating the toxic effects of alcohol.

    McCarty, Mark F

    2013-04-01

    Rodent studies reveal that oxidative stress, much of it generated via induction/activation of NADPH oxidase, is a key mediator of a number of the pathogenic effects of chronic ethanol overconsumption. The highly reactive ethanol metabolite acetaldehyde is a key driver of this oxidative stress, and doubtless works in other ways to promote alcohol-induced pathology. Effective antioxidant measure may therefore be useful for mitigating the adverse health consequences of alcohol consumption; spirulina may have particular utility in this regard, as its chief phycochemical phycocyanobilin has recently been shown to function as an inhibitor of certain NADPH oxidase complexes, mimicking the physiological role of its chemical relatives biliverdin/bilirubin in this respect. Moreover, certain nutraceuticals, including taurine, pantethine, and lipoic acid, may have the potential to boost the activity of the mitochondrial isoform of aldehyde dehydrogenase, ALDH-2, accelerating conversion of acetaldehyde to acetate (which arguably has protective health effects). Little noticed clinical studies conducted nearly three decades ago reported that pre-ingestion of either taurine or pantethine could blunt the rise in blood acetaldehyde following ethanol consumption. Other evidence suggests that lipoic acid may function within mitochondria to maintain aldehyde dehydrogenase in a reduced active conformation; the impact of this agent on ethanol metabolism has however received little or no study. Studies evaluating the impact of nutracetical strategies on prevention of hangovers - which likely are mediated by acetaldehyde - may represent a quick, low-cost way to identify nutraceutical regimens that merit further attention for their potential impact on alcohol-induced pathology. Measures which boost or preserve ALDH-2 activity may also have important antioxidant potential, as this enzyme functions physiologically to protect cells from toxic aldehydes generated by oxidant stress. PMID

  17. Bradykinetic alcohol dehydrogenases make yeast fitter for growth in the presence of allyl alcohol

    Plapp, Bryce V.; Lee, Ann Ting-I.; Khanna, Aditi; Pryor, John M.

    2012-01-01

    Previous studies showed that fitter yeast (Saccharomyces cerevisiae) that can grow by fermenting glucose in the presence of allyl alcohol, which is oxidized by alcohol dehydrogenase I (ADH1) to toxic acrolein, had mutations in the ADH1 gene that led to decreased ADH activity. These yeast may grow more slowly due to slower reduction of acetaldehyde and a higher NADH/NAD+ ratio, which should decrease the oxidation of allyl alcohol. We determined steady-state kinetic constants for three yeast AD...

  18. Irradiation effect on the reaction of mixture of carbon monoxide and hydrogen, (3)

    A series of our studies on radiation chemical reaction of CO and H2 mixture indicated that several organic compounds were produced by electron beam irradiation and the amounts of the products increased with increasing pressure and also increased when the irradiation was carried out under circulation. The present study was carried out in an attempt to investigate whether the amounts of the products increase when the mixture is irradiated under circulation at elevated pressure. For this purpose, a reaction apparatus, which can irradiated the mixture up to 10,000 Torr under circulation, was built and the experiments were carried out on the amounts of products as functions of pressure, irradiation time, gas composition, temperature and dose rate. G values of most compounds were found to increased with increasing pressure under circulation. Among the products, the reaction conditions giving high yield of acetaldehyde were studied in detail, since this compound is considered to be one of the most important intermediate compounds in C1 chemistry. The maximum G value of acetaldehyde was 2.9 which was obtained at 8,000 Torr, 55 CO mol%, 2 x 1019 eV.g-1.sec-1, 1.3 x 1020 eV.g-1 and 22 0C. The selectivity favored this compounds in all organic compounds was 57 mol% at the conversion rate of 0.8 %. In order to elucidate the reaction paths of formation and disappearance of acetaldehyde, the amounts of products were determined for the mixture with or without the presence of small amounts of acetadehyde. The results indicate that acetaldehyde formed by irradiation from

  19. Analysis of DNA adducts of some low molecular weight aldehydes : Methods development and application in human biomonitoring

    Fang, Jia-Long

    1997-01-01

    Doctoral Thesis present at the Karolinska Institute, 1997 Center for Nutrition and Toxicology Departrnent of Biosciences at NOVUM Karolinska Institute 141 57 Huddinge Malondialdehyde (MA), acetaldehyde (Aa) and methylglyoxal (MG) are ubiquitously present in the environment and endogenously forrned in animals and humans. They have been shown to be genotoxic and to readily react with DNA to form DNA adducts under physiological conditions. The present studies ...

  20. Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

    Akira Yasutake; Jin Ping Cheng; Masako Kiyono; Shimpei Uraguchi; Xiaojie Liu; Kyoko Miura; Yoshiaki Yasuda; Nikolay Mashyanov

    2011-01-01

    A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air o...

  1. Photocatalytic TiO2 thin films for air cleaning : Effect of facet orientation, chemical functionalization, and reaction conditions

    Stefanov, Bozhidar

    2015-01-01

    Poor indoor air quality is a source of adverse health effects. TiO2 coatings deposited on well-illuminated surfaces, such as window panes, can be used to fully mineralize indoor air pollutants by photocatalysis. In such applications it is important to ensure stable photocatalytic activity for a wide range of operating conditions, such as relative humidity and temperature, and to avoid deactivation of the catalyst. In this thesis photocatalytic removal of the indoor-pollutant acetaldehyde (CH3...

  2. First-pass gastric mucosal metabolism of ethanol is negligible in the rat.

    SMITH, T; DeMaster, E G; Furne, J K; Springfield, J; Levitt, M D

    1992-01-01

    Ethanol metabolism by gastric alcohol dehydrogenase (ADH) is thought to be an important determinant of peripheral ethanol time-concentration curves (AUCs) in rats and humans. We quantitated this metabolism in rats by measuring the gastric absorption of oral ethanol (0.25 g/kg) and the gastric venous-arterial (V-A) difference of ethanol versus ethanol metabolites (acetate, acetaldehyde, and bicarbonate). Over 1 h, approximately 20% of the ethanol was absorbed from the stomach and 70% was empti...

  3. Nucleic acid molecules conferring enhanced ethanol tolerance and microorganisms having enhanced tolerance to ethanol

    Brown, Steven; Guss, Adam; Yang, Shihui; Karpinets, Tatiana; Lynd, Lee; Shao, Xiongjun

    2014-01-14

    The present invention provides isolated nucleic acid molecules which encode a mutant acetaldehyde-CoA/alcohol dehydrogenase or mutant alcohol dehydrogenase and confer enhanced tolerance to ethanol. The invention also provides related expression vectors, genetically engineered microorganisms having enhanced tolerance to ethanol, as well as methods of making and using such genetically modified microorganisms for production of biofuels based on fermentation of biomass materials.

  4. Monomolecular hydrogen elimination in C2H5OH vapor produced by CO2 IR laser pulses

    The authors examine the scope for the formation of acetaldehyde as a result of ethanol vapor photolysis by infrared multiphoton excitation and consequent isomerization via a series of probable reaction channels. The infrared source is a carbon dioxide laser. To estimate the relative probabilities of the channels they perform quantum-chemical calculations by the MINDO/3 method and vary all the independent degrees of freedom

  5. Real-world driving speciated VOC hot start missions of the 2001 French passenger car fleet

    FLANDRIN, Y; Vidon, R; Cazier, F.; Hue, S.; DECHAUX, JC; Nollet, V.

    2001-01-01

    A 25 passenger cars sample was selected on the basis of a 2001 year French fleet prediction. Various types of vehicle technologies, i.e. diesel and petrol cars both equipped with or without catalyst, were tested on a chassis dynamometer with constant volume sampling for regulated emissions and individual Volatile Organic Compounds determination. A particular emphasis has been placed on toxic and/or photochemically reactive compounds such as benzene, formaldehyde, acetaldehyde and 1,3-b...

  6. Ethanol prevents development of destructive arthritis

    Jonsson, Ing-Marie; Verdrengh, Margareta; Brisslert, Mikael; Lindblad, Sofia; Bokarewa, Maria; Islander, Ulrika; Carlsten, Hans; Ohlsson, Claes; Nandakumar, Kutty Selva; Holmdahl, Rikard; Tarkowski, Andrej

    2006-01-01

    Environmental factors are thought to play a major role in the development of rheumatoid arthritis. Because the use of ethanol is widespread, we assessed the role of ethanol intake on the propensity to develop chronic arthritis. Collagen type II-immunized mice were given water or water containing 10% (vol/vol) ethanol or its metabolite acetaldehyde. Their development of arthritis was assessed, as well as the impact of ethanol on leukocyte migration and activation of intracellular transcription...

  7. Effects of ethanol on hepatic cellular replication and cell cycle progression

    Clemens, Dahn L.

    2007-01-01

    Ethanol is a hepatotoxin. It appears that the liver is the target of ethanol induced toxicity primarily because it is the major site of ethanol metabolism. Metabolism of ethanol results in a number of biochemical changes that are thought to mediate the toxicity associated with ethanol abuse. These include the production of acetaldehyde and reactive oxygen species, as well as an accumulation of nicotinamide adenine dinucleotide (NADH). These biochemical changes are associated with the accumula...

  8. Alcohol Dehydrogenase Accentuates Ethanol-Induced Myocardial Dysfunction and Mitochondrial Damage in Mice: Role of Mitochondrial Death Pathway

    GUO Rui; Ren, Jun

    2010-01-01

    Objectives Binge drinking and alcohol toxicity are often associated with myocardial dysfunction possibly due to accumulation of the ethanol metabolite acetaldehyde although the underlying mechanism is unknown. This study was designed to examine the impact of accelerated ethanol metabolism on myocardial contractility, mitochondrial function and apoptosis using a murine model of cardiac-specific overexpression of alcohol dehydrogenase (ADH). Methods ADH and wild-type FVB mice were acutely chall...

  9. Aldehyde dehydrogenase 2 and head and neck cancer: a meta-analysis implementing a Mendelian randomization approach.

    Boccia, Stefania; Hashibe, Mia; Gallì, Paola; De Feo, Emma; Asakage, Takahiro; Hashimoto, Tomoko; Hiraki, Akio; Katoh, Takahiko; Nomura, Takeshi; Yokoyama, Akira; van Duijn, Cornelia M; Ricciardi, Gualtiero; Boffetta, Paolo

    2009-01-01

    Alcohol drinking at high doses is a risk factor for head and neck cancer, and exposure to acetaldehyde, the principle metabolite of alcohol, is supposed to account for the increased risk. Individuals homozygous for the 2 variant allele of aldehyde dehydrogenase 2 (ALDH2) are unable to metabolize acetaldehyde, which prevents them from alcohol drinking, whereas 1 2 have 6-fold higher blood acetaldehyde concentration postalcohol consumption with respect to 1 1. According to the concept of Mendelian randomization, because this polymorphism is distributed randomly during gamete formation, its association with head and neck cancer should be not confounded by smoking. We carried out a meta-analysis of ALDH2 and head and neck cancer searching for relevant studies on Medline and Embase up to January 31, 2008, and investigated the consistency between the expected odds ratio (OR) among drinkers from the largest pooled analysis among never smokers and the observed OR from this meta-analysis by an interaction test. Six studies were selected (945 cases, 2,917 controls). The OR of head and neck cancer among 2 2 was 0.53 [95% confidence interval (95% CI), 0.28-1.00] relative to 1 1 and 1.83 (95% CI, 1.21-2.77) among 1 2. The expected OR for head and neck cancer due to alcohol intake among 1 1 was 1.38 (95% CI, 0.88-2.17) and the observed OR among 1 1 compared with 2*2 from this meta-analysis was 1.88 (95% CI, 1.00-3.57; P for interaction = 0.43). Besides showing the effectiveness of the Mendelian randomization approach, these findings support the theory that alcohol increases head and neck cancer risk through the carcinogenic action of acetaldehyde. PMID:19124505

  10. Ethanolamine utilization in Vibrio alginolyticus

    Khatri Neelam; Khatri Indu; Subramanian Srikrishna; Raychaudhuri Saumya

    2012-01-01

    Abstract Ethanolamine is used as an energy source by phylogenetically diverse bacteria including pathogens, by the concerted action of proteins from the eut-operon. Previous studies have revealed the presence of eutBC genes encoding ethanolamine-ammonia lyase, a key enzyme that breaks ethanolamine into acetaldehyde and ammonia, in about 100 bacterial genomes including members of gamma-proteobacteria. However, ethanolamine utilization has not been reported for any member of the Vibrio genus. O...

  11. Comparative Genomics of Ethanolamine Utilization▿ † ‡

    Tsoy, Olga; Ravcheev, Dmitry; Mushegian, Arcady

    2009-01-01

    Ethanolamine can be used as a source of carbon and nitrogen by phylogenetically diverse bacteria. Ethanolamine-ammonia lyase, the enzyme that breaks ethanolamine into acetaldehyde and ammonia, is encoded by the gene tandem eutBC. Despite extensive studies of ethanolamine utilization in Salmonella enterica serovar Typhimurium, much remains to be learned about EutBC structure and catalytic mechanism, about the evolutionary origin of ethanolamine utilization, and about regulatory links between t...

  12. Comparative genomics of ethanolamine utilization

    Tsoy, Olga; Ravcheev, Dmitry; Mushegian, Arcady

    2009-01-01

    Ethanolamine can be used as a source of carbon and nitrogen by phylogenetically diverse bacteria. Ethanolamine-ammonia lyase, the enzyme that breaks ethanolamine into acetaldehyde and ammonia, is encoded by the gene tandem eutBC. Despite extensive studies of ethanolamine utilization in Salmonella enterica serovar Typhimurium, much remains to be learned about EutBC structure and catalytic mechanism, about the evolutionary origin of ethanolamine utilization, and about regulatory links between t...

  13. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Teodora Emilia RUSU COLDEA; Carmen SOCACIU; Maria PARV; Vodnar, Dan

    2011-01-01

    In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear) were characterized by gas-chromatography (GC-FID). There were collected 26 samples from different locations of Transylvania (Romania), all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, ...

  14. Improving photocatalysts towards innovative market applications: an economic analysis

    Deckers, Nathalie

    2011-01-01

    This work examines the commercial viability of titanium dioxide semiconductor catalysts which are activated under the influence of UV light to degrade acetaldehyde (type of VOC) into H2O and CO2. Firstly, variables influencing the quantity demanded of this technology are listed. Attention has especially been paid to its broad competitive environment. Both its direct (gas-phase filters and ozone generators) and its indirect competitors (source control and ventilation measures) are determined. ...

  15. Eletroxidação do etanol em eletrodos de Ti/IrO2 Electro-oxidation of ethanol in Ti/IrO2

    CARLOS H. V. FIDELIS; Paulo M. Donate; Adalgisa R. de Andrade

    2001-01-01

    It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed ...

  16. Eletroxidação do etanol em eletrodos de Ti/IrO2

    Fidelis Carlos H.V.; Donate Paulo M.; Andrade Adalgisa R. de

    2001-01-01

    It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed ...

  17. Teores de compostos orgânicos em cachaças produzidas na região norte fluminense - Rio de Janeiro Organic compounds contents in cachaças produced in the northern Rio de Janeiro State - RJ

    Leandro Marelli de Souza; Karla Silva Ferreira; Luís César Passoni; Alice Barreto Bevitori; Karen Vieira Melo; Arivaldo Ribeiro Viana

    2009-01-01

    This work aimed to quantify some organic compounds in "cachaças" (sugar cane spirit). The ethyl alcohol was quantified by densimetry, after distillation. The acetic acid, methyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, isoamyl alcohol (mixture of 2-methyl-butyl and 3-methyl-butyl), ethyl acetate and acetaldehyde were determined by gas chromatography; and the furfural, 5-hydroxy-methylfurfural and acrolein by high efficiency liquid chromatography. From the 30 samples analy...

  18. Silica-Titania Composite (STC)'s Performance in the Photocatalytic Oxidation of Polar VOCs

    Levine, Lanfang H.; Coutts, Janelle; Richards, Jeffrey; Mazyck, David; Mazyck, David

    2011-01-01

    The objective of this paper is to determine the performance of a Silica-Titania Composite (STC) in the photocatalytic oxidation (PCO) of polar VOCs for potential applications in trace contaminant control within space habitats such as the ISS and CEV Orion. Tests were carried out in a bench scale STC-packed annular reactor under continuous illumination by either a UV-C germicidal lamp(lambda (sub max) = 254 nm) or UV-A fluorescent BLB (lambda(sub max) = 365 nm) for the removal of ethanol (a predominant polar VOC in the ISS cabin). The STC's performance was evaluated in terms of the ethanol mineralization rate, mineralization efficiency, and the extent of its oxidation intermediate (acetaldehyde) formation in response to the type of light source (photon energy and photon flux) and relative humidity (RH) implemented. Results demonstrated that acetaldehyde was the only quantifiable intermediate in the effluent under UV illumination, but was not found in the dark adsorption experiments. The mineralization rate increased with an increase in photon energy (UV-C greater than UV-A), even though both lamps were adjusted to emit the same incident photon flux, and also increased with increasing photon flux. However, photonic efficiency decreased as the photon flux increased. More importantly, a higher photon flux gave rise to a lower effluent acetaldehyde concentration. The effect of RH on PCO was complex and intriguing because it affected both physical adsorption and photocatalytic oxidation. In general, increasing RH caused a decrease in adsorption capacity for ethanol and reduced the mineralization efficiency with a concomitant higher acetaldehyde evolution rate. The effect of RH was less profound than that of photon flux.

  19. Impact of smoking on lung cancer risk is stronger in those with the homozygous aldehyde dehydrogenase 2 null allele in a Japanese population.

    Park, Ji Young; Matsuo, Keitaro; Suzuki, Takeshi; Ito, Hidemi; Hosono, Satoyo; Kawase, Takakazu; Watanabe, Miki; Oze, Isao; Hida, Toyoaki; Yatabe, Yasushi; Mitsudomi, Tetsuya; Takezaki, Toshiro; Tajima, Kazuo; Tanaka, Hideo

    2010-04-01

    The main lifestyle contributor to acetaldehyde exposure is the drinking of alcoholic beverages, but tobacco smoke also makes some contribution. Although acetaldehyde is associated with upper aerodigestive tract cancer risk, in accordance with genetically determined acetaldehyde metabolism, it is unclear whether lung cancer, a representative smoking-related cancer, is associated with acetaldehyde or genes impacting its metabolism. We conducted a case-control study to examine possible interaction between smoking and aldehyde dehydrogenase 2 (ALDH2) Glu504Lys polymorphism (rs671) on the risk of lung cancer in Japanese. Subjects were 718 lung cancer cases and 1416 non-cancer controls enrolled in the Hospital-based Epidemiologic Research Program at Aichi Cancer Center. Lifestyle factors, including smoking, were determined by self-administered questionnaire. We applied pack-years (PY; categorized into five levels: never, or =45) as a marker of cumulative exposure to smoking. The impact of smoking, ALDH2 genotype, and their interaction on lung cancer risk were assessed by odds ratio (OR) and 95% confidence interval adjusted for potential confounders. Adjusted ORs for PY or =45 relative to never smokers among those with Glu/Glu or Glu/Lys were 1.39, 1.80, 3.44 and 6.25, respectively (P-trend = 1.4 x 10(-30)). In contrast, ORs among Lys/Lys were 1.01, 10.2, 11.4 and 23.2, respectively (P-trend = 2.6 x 10(-7)). Interaction between ALDH2 genotype (Glu/Glu + Glu/Lys versus Lys/Lys) and cumulative smoking dose was statistically significant (P = 0.036) and was consistently observed in the analysis among never-drinkers (interaction P = 0.041). These results suggest that ALDH2 Lys/Lys, a null enzyme activity genotype, modifies the impact of smoking on the risk of lung cancer. PMID:20093384

  20. Alcohol intake and ovarian cancer risk : A pooled analysis of 10 cohort studies

    Genkinger, J.M.; Hunter, D. J.; Spiegelman, D; Anderson, K. E.; Buring, J. E.; Freudenheim, J. L.; Goldbohm, R. A.; Harnack, L.; Hankinson, S E; Larsson, S C; Leitzmann, M; McCullough, M.L.; Marshall, J.; Miller, A.B.; Rodriguez, C.

    2006-01-01

    Alcohol has been hypothesized to promote ovarian carcinogenesis by its potential to increase circulating levels of estrogen and other hormones; through its oxidation byproduct, acetaldehyde, which may act as a cocarcinogen; and by depletion of folate and other nutrients. Case-control and cohort studies have reported conflicting results relating alcohol intake to ovarian cancer risk. We conducted a pooled analysis of the primary data from ten prospective cohort studies. The analysis included 5...

  1. Characterization of volatile compounds of “Drenja”, an alcoholic beverage obtained from the fruits of cornelian cherry

    VELE TEŠEVIĆ; NINOSLAV NIKIĆEVIĆ; SLOBODAN MILOSAVLJEVIĆ; DANICA BAJIĆ; VLATKA VAJS; IVAN VUČKOVIĆ; LJUBODRAG VUJISIĆ; IRIS ĐORĐEVIĆ; MIROSLAVA STANKOVIĆ; MILOVAN VELIČKOVIĆ

    2009-01-01

    In this study, volatile compounds were analyzed in five samples of home-made spirit beverage made by the distillation of fermented fruits of cornelian cherry (Cornus mas L.). The major volatile compounds, besides ethanol, identified and quantified were: methanol, acetaldehyde, 1-propanol, ethyl acetate, 2-methyl-1-propanol, 1-butanol, amyl alcohols, 1-hexanol and 2-phenylethanol. The minor volatiles were submitted to liquid–liquid extraction with dichloromethane and analyzed by gas chromatogr...

  2. Chemical composition and sensory analysis of cheese whey-based beverages using kefir grains as starter culture

    Magalhães, Karina Teixeira; Dias, Disney R.; Pereira, Gilberto V. de Melo; Oliveira, J.M.; Domingues, Lucília; Teixeira, J. A.; João Batista de Almeida e Silva; Schwan, Rosane F.

    2011-01-01

    The aim of the present work was to evaluate the use of the kefir grains as a starter culture for tradicional milk kefir beverage and for cheese whey-based beverages production. Fermentation was performed by inoculating kefir grains in milk (ML), cheese whey (CW) and deproteinised cheese whey (DCW). Erlenmeyers containing kefir grains and different substrates were statically incubated for 72 h at 25 °C. Lactose, ethanol, lactic acid, acetic acid, acetaldehyde, ethyl acetate, isoamyl alcohol, i...

  3. Assessment of Pollutant Spread from a Building Basement with three Ventilation Systems

    Koffi, Juslin

    2009-01-01

    International audience Ventilation aims at providing a sufficient air renewal for ensuring a good indoor air quality (IAQ), yet building energy policies are leading to adapting various ventilation strategies minimising energy losses through air renewal. A recent IAQ evaluation campaign in French dwellings shows important pollution of living spaces by VOCs such as formaldehyde, acetaldehyde or hexanal, particularly in buildings equipped with a garage. Besides, radon emission from soil is a ...

  4. Mechanisms involved in the induction of aneuploidy: the significance of chromosome loss

    A.I. Seoane; Güerci, A.M; F.N. Dulout

    2000-01-01

    The induction of aneuploidy by physical and chemical agents using different test systems was evaluated. The effect of X-rays, caffeine, acetaldehyde, ethanol, diethylstilbestrol, propionaldehyde, and chloral hydrate was studied by chromosome counting in Chinese hamster embryonic diploid cells. Aneugenic ability of cadmium chloride, cadmium sulfate, potassium dichromate, chromium chloride, nickel chloride, and nickel sulfate was assessed by means of anaphase-telophase analysis in Chinese hamst...

  5. Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

    J. C. Gong; Zhu, T.; M. Hu; L. W. Zhang; Cheng, H.; L. Zhang; Tong, J; Zhang, J.

    2010-01-01

    Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's...

  6. Cloning and characterization of a locus encoding an indolepyruvate decarboxylase involved in indole-3-acetic acid synthesis in Erwinia herbicola.

    Brandl, M. T.; Lindow, S E

    1996-01-01

    Erwinia herbicola 299R synthesizes indole-3-acetic acid (IAA) primarily by the indole-3-pyruvic acid pathway. A gene involved in the biosynthesis of IAA was cloned from strain 299R. This gene (ipdC) conferred the synthesis of indole-3-acetaldehyde and tryptophol upon Escherichia coli DH5 alpha in cultures supplemented with L-tryptophan. The deduced amino acid sequence of the gene product has high similarity to that of the indolepyruvate decarboxylase of Enterobacter cloacae. Regions within py...

  7. Research advances in the catalysts for the selective oxidation of ethane to aldehydes

    ZHANG Zhe; ZHAO Zhen; XU Chunming

    2005-01-01

    Selective oxidation of ethane to aldehydes is one of the most difficult processes in the catalysis researches of low alkanes. The development of selective oxidation of ethane to aldehydes (formaldehyde, acetaldehyde and acrolein) is discussed. The latest progress of the catalysts, including bulk or supported metal oxide catalysts, highly dispersed and isolated active sites catalysts, and the photo-catalytic ethane oxidation catalysts, partial oxidation of ethane in the gas phase, and the proposed reaction pathways from ethane to aldehydes are involved.

  8. Analysis of alcohol dehydrogenase inhibitors from Desmodium styracifolium using centrifugal ultrafiltration coupled with HPLC-MS

    Liu Liangliang; Chen Miao; Chen Xiaoqing

    2015-01-01

    Alcohol dehydrogenase (ADH) inhibitors play an important role in the treatment of human methanol or ethylene glycol poisoning and the suppression of acetaldehyde accumulation in alcoholics. In this study, centrifugal ultrafiltration coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) was utilized to screen and identify ADH inhibitors from ethyl acetate extract of Desmosium styracifolium (Osb.) Merr. The experiment conditions of c...

  9. Disulfiram Attenuates Drug-Primed Reinstatement of Cocaine Seeking via Inhibition of Dopamine β-Hydroxylase

    Schroeder, Jason P; Cooper, Debra A.; Schank, Jesse R.; Lyle, Megan A.; Gaval-Cruz, Meriem; Ogbonmwan, Yvonne E.; Pozdeyev, Nikita; Freeman, Kimberly G; Iuvone, P. Michael; Edwards, Gaylen L.; Holmes, Philip V.; Weinshenker, David

    2010-01-01

    The antialcoholism medication disulfiram (Antabuse) inhibits aldehyde dehydrogenase (ALDH), which results in the accumulation of acetaldehyde upon ethanol ingestion and produces the aversive ‘Antabuse reaction' that deters alcohol consumption. Disulfiram has also been shown to deter cocaine use, even in the absence of an interaction with alcohol, indicating the existence of an ALDH-independent therapeutic mechanism. We hypothesized that disulfiram's inhibition of dopamine β-hydroxylase (DBH),...

  10. Salsolinol Facilitates Glutamatergic Transmission to Dopamine Neurons in the Posterior Ventral Tegmental Area of Rats

    Xie, Guiqin; Ye, Jiang-Hong

    2012-01-01

    Although in vivo evidence indicates that salsolinol, the condensation product of acetaldehyde and dopamine, has properties that may contribute to alcohol abuse, the underlying mechanisms have not been fully elucidated. We have reported previously that salsolinol stimulates dopamine neurons in the posterior ventral tegmental area (p-VTA) partly by reducing inhibitory GABAergic transmission, and that ethanol increases glutamatergic transmission to VTA-dopamine neurons via the activation of dopa...

  11. Aldehydes in relation to air pollution sources: A case study around the Beijing Olympics

    Altemose, Brent; Gong, Jicheng; Zhu, Tong; Hu, Min; Zhang, Liwen; Cheng, Hong; Zhang, Lin; Tong, Jian; Kipen, Howard M.; Ohman-Strickland, Pamela; Meng, Qingyu; Robson, Mark G.; Zhang, Junfeng

    2015-05-01

    This study was carried out to characterize three aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein) at a central Beijing site in the summer and early fall of 2008 (from June to October). Aldehydes in polluted atmospheres come from both primary and secondary sources, which limits the control strategies for these reactive compounds. Measurements were made before, during, and after the Beijing Olympics to examine whether the dramatic air pollution control measures implemented during the Olympics had an impact on concentrations of the three aldehydes and their underlying primary and secondary sources. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.3 ± 15.1 μg/m3, 27.1 ± 15.7 μg/m3 and 2.3 ± 1.0 μg/m3, respectively, for the entire period of measurements, all being at the high end of concentration ranges measured in cities around the world in photochemical smog seasons. Formaldehyde and acrolein increased during the pollution control period compared to the pre-Olympic Games, followed the changing pattern of temperature, and were significantly correlated with ozone and with a secondary formation factor identified by principal component analysis (PCA). In contrast, acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period and was significantly correlated with several pollutants emitted from local emission sources (e.g., NO2, CO, and PM2.5). Acetaldehyde was also more strongly associated with primary emission sources including vegetative burning and oil combustion factors identified through the PCA. All three aldehydes were lower during the post-Olympic sampling period compared to the before and during Olympic periods, likely due to seasonal and regional effects. Our findings point to the complexity of source control strategies for secondary pollutants.

  12. Effect of Modified Atmosphere Composition on the Metabolism of Glucose by Brochothrix thermosphacta

    Pin, Carmen; García de Fernando, Gonzalo D.; Ordóñez, Juan A.

    2002-01-01

    The influence of atmosphere composition on the metabolism of Brochothrix thermosphacta was studied by analyzing the consumption of glucose and the production of ethanol, acetic and lactic acids, acetaldehyde, and diacetyl-acetoin under atmospheres containing different combinations of carbon dioxide and oxygen. When glucose was metabolized under oxygen-free atmospheres, lactic acid was one of the main end products, while under atmospheres rich in oxygen mainly acetoin-diacetyl was produced. Th...

  13. Near-explicit Gas-phase Chemistry Coupled with Extensive Aqueous Mechanism: Looking at Ethanol (E85) Exhaust in a Fog

    Ginnebaugh, D. L.; Jacobson, M. Z.

    2011-12-01

    We combine a near-explicit gas-phase chemical mechanism with an extensive aqueous mechanism in a chemical solver to examine the effects of ethanol (E85) versus gasoline on the fate of pollutants in the presence of a fog. We use the Master Chemical Mechanism (MCM, version 3.1, Leeds University) and the Chemical Aqueous Phase Radical Mechanism, CAPRAM 3.0, with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate complex chemistry. The MCM has over 13, 500 organic reactions and 4,600 species, while CAPRAM treats aqueous chemistry among 390 species and 829 reactions (including 51 gas-to-aqueous phase reactions). We validate a simplified version of the model against results from a comprehensive intercomparison by Barth et al (2003). In previous work on ethanol (E85), we analyzed the temperature-dependence of ethanol and gasoline exhaust chemistry and its impact on urban air pollution considering only gas-phase chemistry. In addition to the air pollution findings, we verified that using the MCM with SMVGEAR is practical in a 3-D model. Here, we extend our study to include aqueous chemistry in the presence of a fog. We investigate the impact aqueous reactions have on unburned ethanol and acetaldehyde mixing ratios in the atmosphere in particular because acetaldehyde is an ozone precursor and carcinogen, and aqueous oxidation has potential to speed the conversion of unburned ethanol to acetaldehyde. Acetaldehyde also forms acetic acid in aqueous solution. Acetic acid vapor is an eye, nose, and lung irritant, so both species contribute negatively to human health. We look at the impact of fog liquid water content and temperature on the degradation of emitted aromatic and other species as well, from both gasoline and E85.

  14. Evaluation of Volatile Organic Compounds and Carbonyl Compounds Present in the Cabins of Newly Produced, Medium- and Large-Size Coaches in China

    Yan-Yang Lu; Yi Lin; Han Zhang; Dongxiao Ding; Xia Sun; Qiansheng Huang; Lifeng Lin; Ya-Jie Chen; Yu-Lang Chi; Sijun Dong

    2016-01-01

    An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs) and carbonyl compounds (CCs) in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, a...

  15. Overview of the role of alcohol dehydrogenase and aldehyde dehydrogenase and their variants in the genesis of alcohol-related pathology.

    Crabb, David W; Matsumoto, Michinaga; Chang, David; You, Min

    2004-02-01

    Alcohol dehydrogenase (ADH) and mitochondrial aldehyde dehydrogenase (ALDH2) are responsible for metabolizing the bulk of ethanol consumed as part of the diet and their activities contribute to the rate of ethanol elimination from the blood. They are expressed at highest levels in liver, but at lower levels in many tissues. This pathway probably evolved as a detoxification mechanism for environmental alcohols. However, with the consumption of large amounts of ethanol, the oxidation of ethanol can become a major energy source and, particularly in the liver, interferes with the metabolism of other nutrients. Polymorphic variants of the genes for these enzymes encode enzymes with altered kinetic properties. The pathophysiological effects of these variants may be mediated by accumulation of acetaldehyde; high-activity ADH variants are predicted to increase the rate of acetaldehyde generation, while the low-activity ALDH2 variant is associated with an inability to metabolize this compound. The effects of acetaldehyde may be expressed either in the cells generating it, or by delivery of acetaldehyde to various tissues by the bloodstream or even saliva. Inheritance of the high-activity ADH beta2, encoded by the ADH2*2 gene, and the inactive ALDH2*2 gene product have been conclusively associated with reduced risk of alcoholism. This association is influenced by gene-environment interactions, such as religion and national origin. The variants have also been studied for association with alcoholic liver disease, cancer, fetal alcohol syndrome, CVD, gout, asthma and clearance of xenobiotics. The strongest correlations found to date have been those between the ALDH2*2 allele and cancers of the oro-pharynx and oesophagus. It will be important to replicate other interesting associations between these variants and other cancers and heart disease, and to determine the biochemical mechanisms underlying the associations. PMID:15099407

  16. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Ozeki, K.; Hirakuri, K. K.; Masuzawa, T.

    2011-04-01

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO2) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO2 films and DLC/TiO2/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO2-coated and the DLC/TiO2/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO2 coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO2/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO2/DLC film had a photocatalytic effect even though the TiO2 film was covered with the DLC film.

  17. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO2) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO2 films and DLC/TiO2/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO2-coated and the DLC/TiO2/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO2 coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO2/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO2/DLC film had a photocatalytic effect even though the TiO2 film was covered with the DLC film.

  18. TiO2 Nanotubes with Open Channels as Deactivation-Resistant Photocatalyst for the Degradation of Volatile Organic Compounds.

    Weon, Seunghyun; Choi, Wonyong

    2016-03-01

    We synthesized ordered TiO2 nanotubes (TNT) and compared their photocatalytic activity with that of TiO2 nanoparticles (TNP) film during the repeated cycles of photocatalytic degradation of gaseous toluene and acetaldehyde to test the durability of TNT as an air-purifying photocatalyst. The photocatalytic activity of TNT showed only moderate reduction after the five cycles of toluene degradation, whereas TNP underwent rapid deactivation as the photocatalysis cycles were repeated. Dynamic SIMS analysis showed that carbonaceous deposits were formed on the surface of TNP during the photocatalytic degradation of toluene, which implies that the photocatalyst deactivation should be ascribed to the accumulation of recalcitrant degradation intermediates (carbonaceous residues). In more oxidizing atmosphere (100% O2 under which less carbonaceous residues should form), the photocatalytic activity of TNP still decreased with repeating cycles of toluene degradation, whereas TNT showed no sign of deactivation. Because TNT has a highly ordered open channel structure, O2 molecules can be more easily supplied to the active sites with less mass transfer limitation, which subsequently hinders the accumulation of carbonaceous residues on TNT surface. Contrary to the case of toluene degradation, both TNT and TNP did not exhibit any significant deactivation during the photocatalytic degradation of acetaldehyde, because the generation of recalcitrant intermediates from acetaldehyde degradation is insignificant. The structural characteristics of TNT is highly advantageous in preventing the catalyst deactivation during the photocatalytic degradation of aromatic compounds. PMID:26854616

  19. Enzymes involved in vinyl acetate decomposition by Pseudomonas fluorescens PCM 2123 strain.

    Szczyrba, Elżbieta; Greń, Izabela; Bartelmus, Grażyna

    2014-03-01

    Esterases are widely used in food processing industry, but there is little information concerning enzymes involved in decompositions of esters contributing to pollution of environment. Vinyl acetate (an ester of vinyl alcohol and acetic acid) is a representative of volatile organic compounds (VOCs) in decomposition, of which hydrolyses and oxidoreductases are mainly involved. Their activities under periodically changing conditions of environment are essential for the removal of dangerous VOCs. Esterase and alcohol/aldehyde dehydrogenase activities were determined in crude cell extract from Pseudomonas fluorescens PMC 2123 after vinyl acetate induction. All examined enzymes exhibit their highest activity at 30-35 °C and pH 7.0-7.5. Esterase preferably hydrolyzed ester bonds with short fatty chains without plain differences for C2 or C4. Comparison of Km values for alcohol and aldehyde dehydrogenases for acetaldehyde suggested that this metabolite was preferentially oxidized than reduced. Activity of alcohol dehydrogenase reducing acetaldehyde to ethanol suggested that one mechanism of defense against the elevated concentration of toxic acetaldehyde could be its temporary reduction to ethanol. Esterase activity was inhibited by phenylmethanesulfonyl fluoride, while β-mercaptoethanol, dithiothreitol, and ethylenediaminetetraacetic acid had no inhibitor effect. From among metal ions, only Mg(2+) and Fe(2+) stimulated the cleavage of ester bond. PMID:23913099

  20. Measurements of OVOC fluxes by eddy covariance using a proton-transfer-reaction mass spectrometer - method development at a coastal site

    Yang, M.; Beale, R.; Smyth, T.; Blomquist, B.

    2013-07-01

    We present here vertical fluxes of oxygenated volatile organic compounds (OVOCs) measured with eddy covariance (EC) during the period of March to July 2012 near the southwest coast of the United Kingdom. The performance of the proton-transfer-reaction mass spectrometer (PTR-MS) for flux measurement is characterized, with additional considerations given to the homogeneity and stationarity assumptions required by EC. Observed mixing ratios and fluxes of OVOCs (specifically methanol, acetaldehyde, and acetone) vary significantly with time of day and wind direction. Higher mixing ratios and fluxes of acetaldehyde and acetone are found in the daytime and from the direction of a forested park, most likely due to light-driven emissions from terrestrial plants. Methanol mixing ratio and flux do not demonstrate consistent diel variability, suggesting sources in addition to plants. We estimate air-sea exchange and photochemical rates of these compounds, which are compared to measured vertical fluxes. For acetaldehyde, the mean (1σ) mixing ratio of 0.13 (0.02) ppb at night may be maintained by oceanic emission, while photochemical destruction outpaces production during the day. Air-sea exchange and photochemistry are probably net sinks of methanol and acetone in this region. Their nighttime mixing ratios of 0.46 (0.20) and 0.39 (0.08) ppb appear to be affected more by terrestrial emissions and long-distance transport, respectively.

  1. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Ozeki, K., E-mail: ozeki@mx.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Frontier Research Center for Applied Atomic Sciences, 162-1 Shirakata, Toukai, Ibaraki 319-1106 (Japan); Hirakuri, K.K. [Applied Systems Engineering, Graduate School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama 350-0394 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan)

    2011-04-15

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO{sub 2}) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO{sub 2} films and DLC/TiO{sub 2}/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO{sub 2}-coated and the DLC/TiO{sub 2}/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO{sub 2} coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO{sub 2}/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO{sub 2}/DLC film had a photocatalytic effect even though the TiO{sub 2} film was covered with the DLC film.

  2. Variation of ambient carbonyl levels in urban Beijing between 2005 and 2012

    Chen, Wentai; Shao, Min; Wang, Ming; Lu, Sihua; Liu, Ying; Yuan, Bin; Yang, Yudong; Zeng, Limin; Chen, Zhongming; Chang, Chih-Chung; Zhang, Qian; Hu, Min

    2016-03-01

    Carbonyl compounds are important precursors of secondary air pollutants. With the rapid economic development and the implementation of stricter control measures in Beijing, the sources of carbonyls possibly changed. Based on measurement data obtained at an urban site in Beijing between 2005 and 2012, we investigated annual variations in carbonyl levels and sources during these years. In summer, formaldehyde and acetaldehyde levels decreased significantly at a rate of 9.1%/year and 7.2%/year, respectively, while acetone levels increased at a rate of 4.3%/year. In winter, formaldehyde levels increased and acetaldehyde levels decreased. We also investigated the factors driving the variation in carbonyls levels during summer by determination of emission ratios for carbonyls and their precursors, and calculation of photochemical formation of carbonyls. The relative declines for primary formaldehyde and acetaldehyde levels were larger than those for secondary formation. This is possibly due to the increasing usage of natural gas and liquefied petroleum gas which could result in the rise of carbonyl precursor emission ratios. The increase in acetone levels might be related to the rising solvent usage in Beijing during these years. The influences of these sources should be paid more attention in future research.

  3. Exposure and inequality for select urban air pollutants in the Tampa Bay area.

    Yu, Haofei; Stuart, Amy L

    2016-05-01

    Air pollution exposure has been linked to numerous adverse health effects, with some disadvantaged subgroups disproportionately burdened. The objective of this work was to characterize distributions of emissions and concentrations of a few important urban air toxics at high spatiotemporal resolution in order to assess exposure and inequality. Benzene, 1,3-butadiene, formaldehyde, and acetaldehyde were the focus pollutants, with oxides of nitrogen (NOx) estimated for comparisons. Primary pollutant emissions were estimated for the full spectrum of source types in the Tampa area using a hybrid approach that is most detailed for major roadways and includes hourly variations in vehicle speed. Resultant pollutant concentrations were calculated using the CALPUFF dispersion model, and combined with CMAQ model output to account for secondary formation of formaldehyde and acetaldehyde. Census demographic data were applied to estimate residential pollution exposures and inequality among population subgroups. Estimated concentrations of benzene, 1,3-butadiene, and NOx were generally higher in urban areas and lower in rural areas. Exposures to these pollutants were disproportionately high for subgroups characterized as black, Hispanic and low income (annual household income less than $20,000). For formaldehyde and acetaldehyde, the patterns of concentration and exposure were largely reversed. Results suggest that disparities in exposure depend on pollutant type. PMID:26895157

  4. The role of surface reactions on the active and selective catalyst design for bioethanol steam reforming

    Benito, M.; Padilla, R.; Serrano-Lotina, A.; Rodríguez, L.; Brey, J. J.; Daza, L.

    In order to study the role of surface reactions involved in bioethanol steam reforming mechanism, a very active and selective catalyst for hydrogen production was analysed. The highest activity was obtained at 700 °C, temperature at which the catalyst achieved an ethanol conversion of 100% and a selectivity to hydrogen close to 70%. It also exhibited a very high hydrogen production efficiency, higher than 4.5 mol H 2 per mol of EtOH fed. The catalyst was operated at a steam to carbon ratio (S/C) of 4.8, at 700 °C and atmospheric pressure. No by-products, such as ethylene or acetaldehyde were observed. In order to consider a further application in an ethanol processor, a long-term stability test was performed under the conditions previously reported. After 750 h, the catalyst still exhibited a high stability and selectivity to hydrogen production. Based on the intermediate products detected by temperature programmed desorption and reaction (TPD and TPR) experiments, a reaction pathway was proposed. Firstly, the adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Secondly, the adsorbed acetaldehyde is transformed into acetone via acetic acid formation. Finally, acetone is reformed to produce hydrogen and carbon dioxide, which were the final reaction products. The promotion of such reaction sequence is the key to develop an active, selective and stable catalyst, which is the technical barrier for hydrogen production by ethanol reforming.

  5. The role of surface reactions on the active and selective catalyst design for bioethanol steam reforming

    Benito, M. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Ciemat, Av. Complutense 22, 28040 Madrid (Spain); Padilla, R.; Serrano-Lotina, A.; Rodriguez, L.; Daza, L. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Brey, J.J. [Hynergreen Technologies, Av. Buhaira 2, 41018 Sevilla (Spain)

    2009-07-01

    In order to study the role of surface reactions involved in bioethanol steam reforming mechanism, a very active and selective catalyst for hydrogen production was analysed. The highest activity was obtained at 700 C, temperature at which the catalyst achieved an ethanol conversion of 100% and a selectivity to hydrogen close to 70%. It also exhibited a very high hydrogen production efficiency, higher than 4.5 mol H{sub 2} per mol of EtOH fed. The catalyst was operated at a steam to carbon ratio (S/C) of 4.8, at 700 C and atmospheric pressure. No by-products, such as ethylene or acetaldehyde were observed. In order to consider a further application in an ethanol processor, a long-term stability test was performed under the conditions previously reported. After 750 h, the catalyst still exhibited a high stability and selectivity to hydrogen production. Based on the intermediate products detected by temperature programmed desorption and reaction (TPD and TPR) experiments, a reaction pathway was proposed. Firstly, the adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Secondly, the adsorbed acetaldehyde is transformed into acetone via acetic acid formation. Finally, acetone is reformed to produce hydrogen and carbon dioxide, which were the final reaction products. The promotion of such reaction sequence is the key to develop an active, selective and stable catalyst, which is the technical barrier for hydrogen production by ethanol reforming. (author)

  6. Ethanol reduces ripening of 'Royal Gala' apples stored in controlled atmosphere.

    Weber, Anderson; Brackmann, Auri; Both, Vanderlei; Pavanello, Elizandra P; Anese, Rogerio O; Schorr, Márcio R W

    2016-03-01

    This work aims at evaluate ethanol effect of acetaldehyde application in post-storage quality of 'Royal Gala' apples maintenance, and to compare them with consolidated storage techniques. Thus two experiments were performed during the years of 2008 and 2009. In the first experiment (2008), the application of ethanol, acetaldehyde or 1-MCP and ethylene scrubbing were tested. Fruits were stored in controlled atmosphere (CA) with 1.0kPa O2 and 2.0kPa CO2 at 0.5°C. In the second experiment (2009), the treatments tested were ethanol application combined or not with low relative humidity (LRH) and LRH alone. In this experiment, apples were stored in CA with 1.2kPa O2 + 2.5kPa CO2 at 0.5°C. After eight months of storage, 0.5 mL ethanol kg-1 apples month-1 or 0.25 mL acetaldehyde kg-1 apples month-1 increased mealiness, flesh browning, and decays incidence and reduced flesh firmness. In contrast, 0.3 mL ethanol kg-1 apples month-1, tested on second experiment, prevented fruit softening and decreased ACC oxidase activity and ethylene production. Although lower relative humidity was not efficient in maintaining post-storage quality, it enhanced the positive effect of ethanol application at 0.3 mL kg-1 apples month-1. PMID:26871493

  7. Improved reaction kinetics and selectivity by the TiO2-embedded carbon nanofiber support for electro-oxidation of ethanol on PtRu nanoparticles

    Nakagawa, Nobuyoshi; Ito, Yudai; Tsujiguchi, Takuya; Ishitobi, Hirokazu

    2014-02-01

    The electro-oxidation of ethanol by the catalyst of PtRu nanoparticles supported on a TiO2-embedded carbon nanofiber (PtRu/TECNF), which has recently been proposed by the authors as a highly active catalyst for methanol oxidation, is investigated by cyclic voltammetry using a glassy carbon electrode and by operating a direct ethanol fuel cell (DEFC) with the catalyst. The mass activity obtained from the cyclic voltammogram for the ethanol oxidation is compared to that for the methanol oxidation reported in our recent paper. The mass activity for the ethanol oxidation is comparable or slightly higher than that for the methanol oxidation, and the relationship between the TECNF composition, i.e., the Ti/C mass ratio, and the activity are also similar to that for the methanol oxidation. A DEFC fabricated with the PtRu/TECNF shows a higher power output compared to that with the commercial PtRu/C catalyst. An analysis of the reaction products by a simple two-step reaction model reveals that the PtRu/TECNF increases the rate constant for the reaction steps from ethanol to acetaldehyde and subsequently to CO2, but decreases that from acetaldehyde to acetic acid. This means that the PtRu/TECNF improves not only the kinetics, but also the selectivity to acetaldehyde.

  8. Pulse radiolysis study of the formation and the reactivity of baicalin radical anion, and in comparison with rutin, quercetin and acyrlate ester radical anions in ethanol

    Sun Gang [Department of Applied Chemistry, College of Chemical and Molecular Engineering, Peking University, Beijing 100871 (China) and Department of Internal Medicine, Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St Louis, MO 63110 (United States)]. E-mail: gangsun@wustl.edu; Wang Wenfeng [Shanghai Institute of Applied Physics, Academic Sinica, P.O. Box 800-204, Shanghai 201800 (China); Wu Jilan [Department of Applied Chemistry, College of Chemical and Molecular Engineering, Peking University, Beijing 100871 (China)]. E-mail: wangwqchem@pku.edu.cn

    2007-06-15

    The reaction of solvated electrons with baicalin in N{sub 2}-saturated ethanol has been studied by pulse radiolysis. The results show that a solvated electron can add to baicalin and generate a baicalin radical anion with a maximum UV absorbance peak at 360 nm. Its molar extinction coefficient at this wavelength is 1.3x10{sup 4} M{sup -1} cm{sup -1}. The rate constant for the build-up of the baicalin radical anion is 1.3({+-}0.4)x10{sup 10} M{sup -1} s{sup -1}. Decay of the radical anion is induced by a proton transfer reaction and a recombination reaction, which involves a pseudo-first-order reaction with rate constant 2.6({+-}0.4)x10{sup 3} s{sup -1} and a second-order reaction with rate constant 1.3({+-}0.2)x10{sup 9} M{sup -1} s{sup -1}. The effect of acetaldehyde on the decay of the baicalin radical anion was also investigated. Electron transfer between the baicalin radical anion and acetaldehyde was not observed, probably due to the low rate of electron transfer between the baicalin radical anion and acetaldehyde. Reactivity of the rutin, quercetin, baicalin and ethyl acrylate radical anions are also compared.

  9. The aroma of the probiotic yogurts with and without supplements

    Mirjana Hruškar

    2003-07-01

    Full Text Available The purpose of this study was to establish the changes in aromacompounds of fermented milks with probiotics during storage as a function of time and temperature. The aroma compounds concentration in probiotic yogurt samples, during storage at + 4 and +20°C were studied. Acetaldehyde, diacetyl, ethanol and organic acids (lactate, acetate, citrate content were determined during 20 days, every fifth day from the beginning of storage. Acetaldehyde, ethanol, lactic, citric and acetic acid concentration were determined using an enzymatic method, while diacetyl concentration was determined using colorimetric method. The results showed that the acetaldehyde decreased during storage. The decrease was higher at elevated temperature. On the other hand, diacetyl, ethanol and acetic acid increased during storage at both temperatures. The concentration of lactic acid increased during storage at both temperature and at the end of storage it was doubled. The amount of citric acid increased in the same manner. The increase of all organic acids during storage was higher at elevated temperature.

  10. Metabolic regulation and maximal reaction optimization in the central metabolism of a yeast cell

    Kasbawati, Gunawan, A. Y.; Hertadi, R.; Sidarto, K. A.

    2015-03-01

    Regulation of fluxes in a metabolic system aims to enhance the production rates of biotechnologically important compounds. Regulation is held via modification the cellular activities of a metabolic system. In this study, we present a metabolic analysis of ethanol fermentation process of a yeast cell in terms of continuous culture scheme. The metabolic regulation is based on the kinetic formulation in combination with metabolic control analysis to indicate the key enzymes which can be modified to enhance ethanol production. The model is used to calculate the intracellular fluxes in the central metabolism of the yeast cell. Optimal control is then applied to the kinetic model to find the optimal regulation for the fermentation system. The sensitivity results show that there are external and internal control parameters which are adjusted in enhancing ethanol production. As an external control parameter, glucose supply should be chosen in appropriate way such that the optimal ethanol production can be achieved. For the internal control parameter, we find three enzymes as regulation targets namely acetaldehyde dehydrogenase, pyruvate decarboxylase, and alcohol dehydrogenase which reside in the acetaldehyde branch. Among the three enzymes, however, only acetaldehyde dehydrogenase has a significant effect to obtain optimal ethanol production efficiently.

  11. Applicability of gasoline containing ethanol as Thailand's alternative fuel to curb toxic VOC pollutants from automobile emission

    Leong, Shing Tet; Muttamara, S.; Laortanakul, Preecha

    Emission rates of benzene, toluene, m-xylene, formaldehyde and acetaldehyde were measured in a fleet of 16 in-use vehicles. The test was performed on a chassis dynamometer incorporated with Bangkok Driving Cycle test mode. Three different test fuels: unleaded gasoline, gasoline blended with 10% ethanol (E10) and gasoline blended with 15% ethanol (E15) were used to determine the different compositions of exhaust emissions from various vehicles. The effects of ethanol content fuels on emissions were tested by three types of vehicles: cars with no catalytic converter installation, cars with three-way catalytic converter and cars with dual-bed catalytic converter. The test result showed wide variations in the average emission rates with different mileages, fuel types and catalytic converters (benzene: 3.33-56.48 mg/km, toluene: 8.62-124.66 mg/km, m-xylene: 2.97-51.65 mg/km, formaldehyde: 20.82-477.57 mg/km and acetaldehyde: 9.46-219.86 mg/km). There was a modest reduction in emission rate of benzene, toluene and m-xylene in cars using E10 and E15 fuels. Use of ethanol fuels, however, leads to increased formaldehyde and acetaldehyde emission rates. Our analysis revealed that alternative fuels and technologies give significant reduction in toxic VOC pollutants from automobile emission—particularly car with dual-bed catalytic converter using E10 fuel.

  12. Investigation into the mechanism of the Bacillus cereus phosphonoacetaldehyde hydrolase enzyme

    The enzyme phosphonoacetaldehyde hydrolase, isolated from Bacillus cereus, catalyzes the dephosphonylation of phosphonoacetaldehyde yielding acetaldehyde and phosphate. We determined that the enzyme was inactivated when it was incubated with substrate or acetaldehyde in the presence of NaBH4. The chemical modification was determined to be specific for a single lysine residue by the use of active site radiolabeling methodologies. Phosphonatase was incubated with [3H]-NaBH4 and phosphonoacetaldehyde, [14C]-acetaldehyde/NaBH4, and with [C2-3H]-phosphonoacetaldehyde/NaBH4 which yielded radiolabeled enzyme. The latter of these experiments yielded the most specifically labeled phosphonatase as determined by RP-HPLC separation of the peptides generated by a tryptic digest of the enzyme. The active site peptide was purified to homogeneity and its primary structure determined. var-epsilon-N-Ethyl-L-lysine was identified as the radiolabeled component of the sequence. Acetonyl phosphonate was able to protect phosphonatase from phosphonoacetaldehyde/NaBH4 induced inactivation which suggests that the lysine is in the active site

  13. Influence of polymolybdate adsorbates on electrooxidation of ethanol at PtRu nanoparticles: Combined electrochemical, mass spectrometric and X-ray photoelectron spectroscopic studies

    Gralec, Barbara; Lewera, Adam; Kulesza, Pawel J.

    2016-05-01

    The role Keggin-type phosphomolybdate (PMo12O403-) ions (adsorbed on carbon-supported PtRu, PtRu/C) on electrooxidation of ethanol is addressed here. The combined results obtained using Differential Electrochemical Mass Spectrometry, X-ray Photoelectron Spectroscopy and Cyclic Voltammetry are consistent with the view that presence of the Keggin-type polyoxometallate, phosphomolybdate, ions (adsorbates) leads to enlargement of the current densities associated with electrooxidation of ethanol at potentials greater than 700 mV vs. RHE. This increase of the anodic currents is correlated with the higher acetaldehyde yield which is likely to reflect changes in the reaction kinetics (e.g. more dynamic dehydrogenation of ethanol leading to acetaldehyde) or in the reaction mechanism defined by the preferential surface modification resulting not only in faster kinetics but also in higher selectivity with respect to acetaldehyde production. It is apparent from the spectroscopic data that modification of PtRu/C nanoparticles with phosphomolybdate ions leads to suppression of the formation of Ru surface oxides.

  14. EAG and behavioral responses of Helicoverpa armigera males to volatiles from poplar leaves and their combinations with sex pheromone

    邓建宇; 黄永平; 魏洪义; 杜家纬

    2004-01-01

    Electroantennogram (EAG) evaluation of selected compounds from wilted leaves ofblack poplar,Populus nigra,showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol,phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%,50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles should modify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.

  15. Air pollution source apportionment before, during, and after the 2008 Beijing Olympics and association of sources to aldehydes and biomarkers of blood coagulation, pulmonary and systemic inflammation, and oxidative stress in healthy young adults

    Altemose, Brent A.

    Based on principal component analysis (PCA) of air pollution data collected during the Summer Olympic Games held in Beijing, China during 2008, the five source types of air pollution identified -- natural soil/road dust, vehicle and industrial combustion, vegetative burning, oil combustion, and secondary formation, were all distinctly lower during the Olympics. This was particularly true for vehicle and industrial combustion and oil combustion, and during the main games period between the opening and closing ceremonies. The reduction in secondary formation was reflective of a reduction in nitrogen oxides, but this also contributed to increased ozone concentrations during the Olympic period. Among three toxic aldehydes measured in Beijing during the same time period, only acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Accordingly, acetaldehyde was significantly correlated with primary emission sources including vegetative burning and oil combustion, and with several pollutants emitted mainly from primary sources. In contrast, formaldehyde and acrolein increased during the Olympic air pollution control period; accordingly both were significantly correlated with ozone and with the secondary formation source type. These findings indicate primary sources may dominate for acetaldehyde while secondary sources may dominate for formaldehyde and acrolein. Biomarkers for pulmonary inflammation (exhaled breath condensate (EBC) pH, exhaled nitric oxide, and EBC nitrite) and hemostasis and blood coagulation (vWF and sCD62p) were most consistently associated with vehicle and industrial combustion, oil combustion, and vegetative burning. The systemic inflammation biomarker 8-OHdG was most consistently associated with vehicle and industrial combustion. In contrast, the associations between the biomarkers and the aldehydes were generally not significant or in the hypothesized direction, although

  16. Characterizing non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation

    Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

    2012-02-01

    Emissions of non-methane volatile organic compounds (NMVOCs) were determined from a swine concentrated animal feeding operation (CAFO) in North Carolina. NMVOCs were measured in air samples collected in SUMMA and fused-silica lined (FSL) canisters and were analyzed using a gas chromatography flame ionization detection (GC-FID) system. Measurements were made from both an anaerobic lagoon and barn in each of the four seasonal sampling periods during the period June 2007 through April 2008. In each sampling period, nine to eleven canister samples were taken from both the anaerobic lagoon and barn over a minimum of four different days during a period of ˜1 week. Measurements of meteorological and physiochemical parameters were also made during the sampling period. In lagoon samples, six NMVOCs were identified that had significantly larger emissions in comparison to other NMVOCs. This included three alcohols (ethanol, 2-ethyl-1-hexanol, and methanol), two ketones (acetone and methyl ethyl ketone (MEK)) and an aldehyde (acetaldehyde). The overall average fluxes for these NMVOCs, ranged from 0.18 μg m -2 min -1 for 2-ethyl-1-hexanol to 2.11 μg m -2 min -1 for acetone, with seasonal fluxes highest in the summer for four (acetone, acetaldehyde, 2-ethyl-1-hexanol and MEK) of the six compounds In barn samples, there were six NMVOCs that had significantly larger concentrations and emissions in comparison to other NMVOCs. These consisted of two alcohols (methanol and ethanol), an aldehyde (acetaldehyde), two ketones (acetone and 2,3-butanedione), and a phenol (4-methylphenol). Overall average barn concentration ranged from 2.87 ppb for 4-methylphenol to 16.12 ppb for ethanol. Overall average normalized barn emission rates ranged from 0.10 g day -1 AU -1 (1 AU (animal unit) = 500 kg of live animal weight) for acetaldehyde to 0.45 g day -1 AU -1 for ethanol. The NMVOCs, 4-methylphenol and 2,3-butanedione, which have low odor thresholds (odor thresholds = 1.86 ppb and 0

  17. Intrinsic Selectivity and Structure Sensitivity of Rhodium Catalysts for C(2+) Oxygenate Production.

    Yang, Nuoya; Medford, Andrew J; Liu, Xinyan; Studt, Felix; Bligaard, Thomas; Bent, Stacey F; Nørskov, Jens K

    2016-03-23

    Synthesis gas (CO + H2) conversion is a promising route to converting coal, natural gas, or biomass into synthetic liquid fuels. Rhodium has long been studied as it is the only elemental catalyst that has demonstrated selectivity to ethanol and other C2+ oxygenates. However, the fundamentals of syngas conversion over rhodium are still debated. In this work a microkinetic model is developed for conversion of CO and H2 into methane, ethanol, and acetaldehyde on the Rh (211) and (111) surfaces, chosen to describe steps and close-packed facets on catalyst particles. The model is based on DFT calculations using the BEEF-vdW functional. The mean-field kinetic model includes lateral adsorbate-adsorbate interactions, and the BEEF-vdW error estimation ensemble is used to propagate error from the DFT calculations to the predicted rates. The model shows the Rh(211) surface to be ∼6 orders of magnitude more active than the Rh(111) surface, but highly selective toward methane, while the Rh(111) surface is intrinsically selective toward acetaldehyde. A variety of Rh/SiO2 catalysts are synthesized, tested for catalytic oxygenate production, and characterized using TEM. The experimental results indicate that the Rh(111) surface is intrinsically selective toward acetaldehyde, and a strong inverse correlation between catalytic activity and oxygenate selectivity is observed. Furthermore, iron impurities are shown to play a key role in modulating the selectivity of Rh/SiO2 catalysts toward ethanol. The experimental observations are consistent with the structure-sensitivity predicted from theory. This work provides an improved atomic-scale understanding and new insight into the mechanism, active site, and intrinsic selectivity of syngas conversion over rhodium catalysts and may also guide rational design of alloy catalysts made from more abundant elements. PMID:26958997

  18. Aldehyde dehydrogenase type 2 activation by adenosine and histamine inhibits ischemic norepinephrine release in cardiac sympathetic neurons: mediation by protein kinase Cε.

    Robador, Pablo A; Seyedi, Nahid; Chan, Noel Yan-Ki; Koda, Kenichiro; Levi, Roberto

    2012-10-01

    During myocardial ischemia/reperfusion, lipid peroxidation leads to the formation of toxic aldehydes that contribute to ischemic dysfunction. Mitochondrial aldehyde dehydrogenase type 2 (ALDH2) alleviates ischemic heart damage and reperfusion arrhythmias via aldehyde detoxification. Because excessive norepinephrine release in the heart is a pivotal arrhythmogenic mechanism, we hypothesized that neuronal ALDH2 activation might diminish ischemic norepinephrine release. Incubation of cardiac sympathetic nerve endings with acetaldehyde, at concentrations achieved in myocardial ischemia, caused a concentration-dependent increase in norepinephrine release. A major increase in norepinephrine release also occurred when sympathetic nerve endings were incubated in hypoxic conditions. ALDH2 activation substantially reduced acetaldehyde- and hypoxia-induced norepinephrine release, an action prevented by inhibition of ALDH2 or protein kinase Cε (PKCε). Selective activation of G(i/o)-coupled adenosine A(1), A(3), or histamine H(3) receptors markedly inhibited both acetaldehyde- and hypoxia-induced norepinephrine release. These effects were also abolished by PKCε and/or ALDH2 inhibition. Moreover, A(1)-, A(3)-, or H(3)-receptor activation increased ALDH2 activity in a sympathetic neuron model (differentiated PC12 cells stably transfected with H(3) receptors). This action was prevented by the inhibition of PKCε and ALDH2. Our findings suggest the existence in sympathetic neurons of a protective pathway initiated by A(1)-, A(3)-, and H(3)-receptor activation by adenosine and histamine released in close proximity of these terminals. This pathway comprises the sequential activation of PKCε and ALDH2, culminating in aldehyde detoxification and inhibition of hypoxic norepinephrine release. Thus, pharmacological activation of PKCε and ALDH2 in cardiac sympathetic nerves may have significant protective effects by alleviating norepinephrine-induced life-threatening arrhythmias that

  19. Elucidating the Biological Basis for the Reinforcing Actions of Alcohol in the Mesolimbic Dopamine System: The Role of Active Metabolites of Alcohol

    William A Truitt

    2013-08-01

    Full Text Available The development of successful pharmacotherapeutics for the treatment of alcoholism is predicated upon understanding the biological action of alcohol. A limitation of the alcohol research field has been examining the effects of alcohol only and ignoring the multiple biological active metabolites of alcohol. The concept that alcohol is a ‘pro-drug’ is not new. Alcohol is readily metabolized to acetaldehyde within the brain. Acetaldehyde is a highly reactive compound that forms a number of condensation products, including salsolinol and iso-salsolinol (acetaldehyde and dopamine. Recent experiments have established that numerous metabolites of ethanol do have direct CNS action, and could, in part or whole, mediate the reinforcing actions of alcohol within the mesolimbic dopamine system. The mesolimbic dopamine system originates in the ventral tegmental area (VTA and projects to forebrain regions that include the nucleus accumbens (Acb and the medial prefrontal cortex (mPFC and is thought to be the neurocircuitry governing the rewarding properties of drugs of abuse. Within this neurocircuitry there is convincing evidence that; 1 biologically active metabolites of alcohol can directly or indirectly increase the activity of VTA dopamine neurons, 2 alcohol and alcohol metabolites are reinforcing within the mesolimbic dopamine system, 3 inhibiting the alcohol metabolic pathway inhibits the biological consequences of alcohol exposure, 4 alcohol consumption can be reduced by inhibiting/attenuating the alcohol metabolic pathway in the mesolimbic dopamine system, 5 alcohol metabolites can alter neurochemical levels within the mesolimbic dopamine system, and 6 alcohol interacts with alcohol metabolites to enhance the actions of both compounds. The data indicate that there is a positive relationship between alcohol and alcohol metabolites in regulating the biological consequences of consuming alcohol and the potential of alcohol use escalating to

  20. Recovery of propylene glycol from dilute aqueous solutions via reversible reaction with aldehydes

    Broekhuis, R.R.; Lynn, S.; King, C.J. [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering]|[Lawrence Berkeley Lab., CA (United States)

    1993-12-01

    A means is proposed for separating propylene glycol and other compounds bearing multiple hydroxyl groups by reversible chemical reaction. Glycols react with aldehydes in cyclic acetalization reactions to form substituted dioxolanes. Propylene glycol reacts with formaldehyde and acetaldehyde to form 4-methyl-1,3-dioxolane and 2,4-dimethyl-1,3-dioxolane. The reaction is catalyzed homogeneously by strong mineral acids or heterogeneously by cation exchange resins in the acid form. Separation processes utilizing this reaction would include an acetalization step, several distillative separation steps and finally a hydrolysis step in which the reaction is reversed. Both reaction steps must be forced to completion by removing the reaction product simultaneously. The equilibrium and kinetics of the reaction with formaldehyde were studied experimentally in systems catalyzed by Amberlite IR-120 ion exchange resin. A number of solvents were screened for their ability to extract 2,4-dimethyl-1,3-dioxolane from aqueous solution. Aromatic hydrocarbons exhibited the highest distribution into the organic phase. To achieve an effective separation of propylene glycol from aqueous solution by combined reaction with formaldehyde and distillation, formaldehyde would have to be present in excess and would be difficult and costly to separate from the aqueous solution. In reactive distillation using acetaldehyde as a reactant this is not a problem. A large flow of acetaldehyde would be necessary to recover the propylene glycol sufficiently in a distillative process. In a process combining reaction and extraction into an organic solvent this problem is avoided. Process simulation indicates the energy input of such a process is less than half of the energy required in a triple-effect evaporation process. This benefit is offset by higher capital costs and increased complexity in the reaction/extraction process.

  1. Genotoxic consequences of endogenous aldehydes on mouse haematopoietic stem cell function.

    Garaycoechea, Juan I; Crossan, Gerry P; Langevin, Frederic; Daly, Maria; Arends, Mark J; Patel, Ketan J

    2012-09-27

    Haematopoietic stem cells (HSCs) regenerate blood cells throughout the lifespan of an organism. With age, the functional quality of HSCs declines, partly owing to the accumulation of damaged DNA. However, the factors that damage DNA and the protective mechanisms that operate in these cells are poorly understood. We have recently shown that the Fanconi anaemia DNA-repair pathway counteracts the genotoxic effects of reactive aldehydes. Mice with combined inactivation of aldehyde catabolism (through Aldh2 knockout) and the Fanconi anaemia DNA-repair pathway (Fancd2 knockout) display developmental defects, a predisposition to leukaemia, and are susceptible to the toxic effects of ethanol-an exogenous source of acetaldehyde. Here we report that aged Aldh2(-/-) Fancd2(-/-) mutant mice that do not develop leukaemia spontaneously develop aplastic anaemia, with the concomitant accumulation of damaged DNA within the haematopoietic stem and progenitor cell (HSPC) pool. Unexpectedly, we find that only HSPCs, and not more mature blood precursors, require Aldh2 for protection against acetaldehyde toxicity. Additionally, the aldehyde-oxidizing activity of HSPCs, as measured by Aldefluor stain, is due to Aldh2 and correlates with this protection. Finally, there is more than a 600-fold reduction in the HSC pool of mice deficient in both Fanconi anaemia pathway-mediated DNA repair and acetaldehyde detoxification. Therefore, the emergence of bone marrow failure in Fanconi anaemia is probably due to aldehyde-mediated genotoxicity restricted to the HSPC pool. These findings identify a new link between endogenous reactive metabolites and DNA damage in HSCs, and define the protective mechanisms that counteract this threat. PMID:22922648

  2. Closing the peroxy acetyl (PA radical budget: observations of acyl peroxy nitrates (PAN, PPN, and MPAN during BEARPEX 2007

    B. W. LaFranchi

    2009-04-01

    Full Text Available Acyl peroxy nitrates (APNs, also known as PANs are formed from the oxidation of aldehydes and other oxygenated VOC (oVOC in the presence of NO2. Formation of APNs suppresses NOx (NOx≡NO+NO2 in urban areas and enhances NOx downwind in urban plumes, increasing the rate of ozone production throughout an urban plume. APNs also redistribute NOx on global scales, enhancing NOx and thus ozone production. There are both anthropogenic and biogenic oVOC precursors to APNs, but a detailed evaluation of their chemistry against observations has proven elusive. Here we describe measurements of PAN, PPN, and MPAN along with the majority of chemicals that participate in their production and loss, including OH, HO2, numerous oVOC, and NO2. Observations were made during the Biosphere Effects on AeRosols and Photochemistry Experiment (BEARPEX 2007 in the outflow of the Sacramento urban plume. These observations are used to evaluate a detailed chemical model of APN ratios and concentrations. We find the ratios of APNs are nearly independent of the loss mechanisms and thus an especially good test of our understanding of their sources. We show that oxidation of methylvinyl ketone, methacrolein, methyl glyoxal, biacetyl and acetaldehyde are all significant sources of the PAN+peroxy acetyl (PA radical reservoir, with methylvinyl ketone (MVK often being the primary non-acetaldehyde source. At high temperatures, oxidation of non-acetaldehyde PA radical sources contributes over 60% to the total PA production rate. An analysis of absolute APN concentrations reveals a missing APN sink that can be resolved by increasing the PA+∑RO2 rate constant by a factor of 3.

  3. Light-absorbing aldol condensation products in acidic aerosols: Spectra, kinetics, and contribution to the absorption index

    Nozière, Barbara; Esteve, William

    The radiative properties of aerosols that are transparent to light in the near-UV and visible, such as sulfate aerosols, can be dramatically modified when mixed with absorbing material such as soot. In a previous work we had shown that the aldol condensation of carbonyl compounds produces light-absorbing compounds in sulfuric acid solutions. In this work we report the spectroscopic and kinetic parameters necessary to estimate the effects of these reactions on the absorption index of sulfuric acid aerosols in the atmosphere. The absorption spectra obtained from the reactions of six different carbonyl compounds (acetaldehyde, acetone, propanal, butanal, 2-butanone, and trifluoroacetone) and their mixtures were compared over 190-1100 nm. The results indicated that most carbonyl compounds should be able to undergo aldol condensation. The products are oligomers absorbing light in the 300-500 nm region where few other compounds absorb, making them important for the radiative properties of aerosols. Kinetic experiments in 96-75 wt% H 2SO 4 solutions and between 273 and 314 K gave an activation energy for the rate constant of formation of the aldol products of acetaldehyde of -(70±15) kJ mol -1 in 96 wt% solution and showed that the effect of acid concentration was exponential. A complete expression for this rate constant is proposed where the absolute value in 96 wt% H 2SO 4 and at 298 K is scaled to the Henry's law coefficient for acetaldehyde and the absorption cross-section for the aldol products assumed in this work. The absorption index of stratospheric sulfuric acid aerosols after a 2-year residence time was estimated to 2×10 -4, optically equivalent to a content of 0.5% of soot and potentially significant for the radiative forcing of these aerosols and for satellite observations in channels where the aldol products absorb.

  4. Comparison of Carbonyls and BTEX Emissions from a Light Duty Vehicle Fuelled with Gasoline and Ethanol-Gasoline Blend, and Operated without 3-Way Catalytic Converter

    Asad Naeem Shah

    2011-10-01

    Full Text Available This paper presents the comparison of unregulated emissions such as carbonyls and BTEX (Benzene, Toluene, Ethyl Benzene, and Xylenes species emanated from a light duty SI (Spark Ignition vehicle E-0 (fuelled on gasoline and E-10 (ethanol-gasoline blend. Meanwhile, the ozone forming potential of these pollutants based on their ozone SR (Specific Reactivity has also been addressed in this study. The experiments were performed on transient as well as steady-state modes in accordance with the standard protocols recommended for light duty vehicle emissions. Carbonyls and BTEX were analyzed by HPLC (High Performance Liquid Chromatography with UV detector and GC/MS (Gas Chromatography/Mass Spectroscopy, respectively. Formaldehyde and acetaldehyde were the predominant components of the carbonyls for E-0 and E-10, respectively. During transient mode, formaldehyde, acrolein + acetone, and tolualdehyde pollutants were decreased but, acetaldehyde emissions increased with E-10 as compared to E-0. The BTEX emissions were also decreased with E-10, relative to E-0. During the steady-state modes, formaldehyde, acrolein + acetone and propionaldehyde were lower, aromatic aldehydes were absent, but acetaldehyde pollutants were higher with E-10 compared to E-0. The BTEX emissions were decreased at medium and higher speed modes however, increased at lower speed mode with E-10 as compared to E-0. Total BTEX emissions were maximal at lower speed mode but, least at medium speed mode for both the fuels. SR of the pollutants was higher over transient cycle of operation, compared with steady-state mode. Relative to E-0, E-10 displayed lower SR during both transient as well as steady-state mode.

  5. Automated and quantitative headspace in-tube extraction for the accurate determination of highly volatile compounds from wines and beers.

    Zapata, Julián; Mateo-Vivaracho, Laura; Lopez, Ricardo; Ferreira, Vicente

    2012-03-23

    An automatic headspace in-tube extraction (ITEX) method for the accurate determination of acetaldehyde, ethyl acetate, diacetyl and other volatile compounds from wine and beer has been developed and validated. Method accuracy is based on the nearly quantitative transference of volatile compounds from the sample to the ITEX trap. For achieving that goal most methodological aspects and parameters have been carefully examined. The vial and sample sizes and the trapping materials were found to be critical due to the pernicious saturation effects of ethanol. Small 2 mL vials containing very small amounts of sample (20 μL of 1:10 diluted sample) and a trap filled with 22 mg of Bond Elut ENV resins could guarantee a complete trapping of sample vapors. The complete extraction requires 100 × 0.5 mL pumping strokes at 60 °C and takes 24 min. Analytes are further desorbed at 240 °C into the GC injector under a 1:5 split ratio. The proportion of analytes finally transferred to the trap ranged from 85 to 99%. The validation of the method showed satisfactory figures of merit. Determination coefficients were better than 0.995 in all cases and good repeatability was also obtained (better than 7% in all cases). Reproducibility was better than 8.3% except for acetaldehyde (13.1%). Detection limits were below the odor detection thresholds of these target compounds in wine and beer and well below the normal ranges of occurrence. Recoveries were not significantly different to 100%, except in the case of acetaldehyde. In such a case it could be determined that the method is not able to break some of the adducts that this compound forms with sulfites. However, such problem was avoided after incubating the sample with glyoxal. The method can constitute a general and reliable alternative for the analysis of very volatile compounds in other difficult matrixes. PMID:22340891

  6. Mechanism and kinetics of Fischer-Tropsch synthesis over supported ruthenium catalysts

    Kellner, C.S.

    1981-06-01

    A detailed study of the kinetics of the Fischer-Tropsch synthesis of hydrocarbons, methanol, and acetaldehyde, over alumina- and silica-supported ruthenium catalysts has been carried out over a broad range of reaction conditions. Based on these results and information taken from the literature, mechanisms for the formation of normal paraffins, ..cap alpha..-olefins, methanol, and acetaldehyde have been proposed. Rate data were obtained between 448 and 548K, 1 and 10 atm, and H/sub 2//CO ratios between 1 and 3, utilizing a micro flow reactor operated at very low conversions. In addition to the studies performed with H/sub 2//CO mixtures, a series of experiments were carried out utilizing D/sub 2//CO mixtures. These studies were used to help identify rate limited steps and steps that were at equilibrium. A complementary investigation, carried out by in situ infrared spectroscopy, was performed using a Fourier Transform spectrometer. The spectra obtained were used to identify the modes of CO adsorption, the CO coverage, and the relative reactivity of different forms of adsorbed CO. It was established that CO adsorbs on alumina-supported Ru in, at least, two forms: (i) Ru-CO and (ii) OC-Ru-CO. Only the first of these forms participates in CO hydrogenation. The coverage of this species is described by a simple Langmuir isotherm. A reaction mechanism is presented for interpreting the kinetics of hydrocarbon synthesis, the olefin to paraffin ratio for each product, and the probability of chain propagation. Rate expressions based on this mechanism are reasonably consistent with the experimental data. Acetaldehyde, obtained mainly over silica-supported Ru, appears to be formed by a mechanism related to that for hydroformulation of olefins. The effect of the dispersion of Ru/Al/sub 2/O/sub 3/ catalysts on their specific activity and selectivity was also investigated. The specific activity for all products decreased rapidly with increasing dispersions.

  7. Exploratory study on the pyrolysis and PAH emissions of polylactic acid

    Chien, Yi-Chi; Liang, Chenju; Yang, Shu-hua

    2011-01-01

    The emission factors for 16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs) from the polylactic acid (PLA) pyrolysis and the decomposition mechanism were investigated in this study. The fragments and gas compositions using on-line thermogravimetry-mass spectrometry (TG-MS) were determined. A temperature series of 7 fragments was analyzed in helium, and was found to include: m/z = 16, which may represent methane; 28, which may be carbon monoxide; 44, which may be acetaldehyde; 56, which may be methylketene, 144, which may be oligomers of lactide. In addition, there are little amount of 100, and 200 which are oligomers of lactides observed in the pyrolysis of PLA. The pyrolysis of PLA is a non-radical, backbiting ester interchange reaction involving the OH chain ends. Depending on the size of the cyclic transition state, the product can be a lactide molecule, an oligomeric ring with more than two repeat units, methylketene, or acetaldehyde. Carbon monoxide and methane are contributions from the decomposition of acetaldehyde. Experimentally, not detected (n.d.)-40.47 μg of 16 PAH emissions were determined from per gram of PLA pyrolysis. The PAH profiles showed a predominance of naphthalene (58.9%), phenanthrene (12.5%), and fluoranthene (5.9%). The total PAH emissions for PLA pyrolysis is significantly lower than the values associated with PLA combustion. From the viewpoint of air pollution control, this result suggests that pyrolysis seems a better alternative than combustion for the disposal of waste PLA. Also, since pyrolysis is the first step for an incineration process, these results can provide important information on the control of PAHs formation for a commercialized incinerator.

  8. Quantification of aldehyde impurities in poloxamer by 1H NMR spectrometry

    This work presents a fast and simple quantitative method for impurity determination of acetaldehyde and propionaldehyde in poloxamer 188 by proton nuclear magnetic resonance spectroscopy (1H NMR). The sample is dissolved in D2O with DCl and analyzed with a 600 MHz NMR spectrometer. Data processing, including filtering by convolution of spectra with a triangular function and integration, is performed in MATLAB. The repeated studies of one sample, including automatic gradient shimming and data processing, revealed a relative standard deviation (R.S.D.) of 2.8%. For the reproducibility, also including sample preparation, the R.S.D. was less than 10%. The predictability of a linear calibration model was estimated by the root mean square error of prediction from leave-one-out cross-validation (RMSECV). Using 64 scans, RMSECV was found to be 7.2 and 5.5 μg g-1 for acetaldehyde and propionaldehyde respectively for a 4.3-min acquisition time. The limits of detection, defined as three times the noise, reached 19 and 15 μg g-1 respectively under the same experimental conditions. These limits are sufficient to quantify 80 and 100 μg g-1 of the impurities, which has been found to be the maximum allowed content in the poloxamer for some medical applications. Thus the method has the potential to replace the current liquid chromatography (LC) method for impurity determination of acetaldehyde and propionaldehyde in poloxamer, which is time-consuming and includes a work-up procedure involving many steps

  9. Assessment of the impact of oxidation processes on indoor air pollution using the new time-resolved INCA-Indoor model

    Mendez, Maxence; Blond, Nadège; Blondeau, Patrice; Schoemaecker, Coralie; Hauglustaine, Didier A.

    2015-12-01

    INCA-Indoor, a new indoor air quality (IAQ) model, has been developed to simulate the concentrations of volatile organic compounds (VOC) and oxidants considering indoor air specific processes such as: emission, ventilation, surface interactions (sorption, deposition, uptake). Based on the detailed version of SAPRC-07 chemical mechanism, INCA-Indoor is able to analyze the contribution of the production and loss pathways of key chemical species (VOCs, oxidants, radical species). The potential of this model has been tested through three complementary analyses: a comparison with the most detailed IAQ model found in the literature, focusing on oxidant species; realistic scenarios covering a large range of conditions, involving variable OH sources like HONO; and the investigation of alkenes ozonolysis under a large range of indoor conditions that can increase OH and HO2 concentrations. Simulations have been run changing nitrous acid (HONO) concentrations, NOx levels, photolysis rates and ventilation rates, showing that HONO can be the main source of indoor OH. Cleaning events using products containing D-limonene have been simulated at different periods of the day. These scenarios show that HOX concentrations can significantly increase in specific conditions. An assessment of the impact of indoor chemistry on the potential formation of secondary species such as formaldehyde (HCHO) and acetaldehyde (CH3CHO) has been carried out under various room configuration scenarios and a study of the HOx budget for different realistic scenarios has been performed. It has been shown that, under the simulation conditions, formaldehyde can be affected by oxidant concentrations via chemical production which can account for more than 10% of the total production, representing 6.5 ppb/h. On the other hand, acetaldehyde production is affected more by oxidation processes. When the photolysis rates are high, chemical processes are responsible for about 50% of the total production of

  10. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area

  11. Overseas chemical industry Hand book

    This book introduces overseas chemical industry, which deals with General chemistry on economic view in the world and prospect and current situation over chemical industry, organic chemistry material on production and demand such as petrochemistry, Energy Supply, Ethylene, Propylene, BTX, Ethylene glycol, Acetaldehyde, Acetic acid, Vinyl Acetate Monomer, PVA, Acrylonitrile, Acrylic esters, Propylene oxide, Propylene Glycol, PPG, Phenol, Acetone, Isopropyl Alcohol, Butanol, Octanol, Methanol, Formalin, Caprolactam Cyclohexane, PTA/DMT, Polyisocyanate, MEK/MIBK, 1.4-BG/THF, Phthalic anhydride and Maleic Anhydride.

  12. Genes that modulate susceptibility for alcohol dependence

    Caio Cesar Silva de Cerqueira; Domingos Lázaro Souza Rios

    2008-01-01

    The pathways for the metabolism of the alcohol are complex and modulated by some genes that promote response to this substance. The genes that codify the enzyme alcohol dehydrogenase (os genes ADH1B or ADH2) act in the conversion of ethanol in acetaldehyde; the enzyme aldehyde dehydrogenase (ALDH2) that converts the aldehyde into ascetic acid, and the gene that codifies the enzyme cytochrome P450, isoform 2E1 (CYP2E1), that acts generating free radicals of great importance in the induced hepa...

  13. Coenzyme A-acylating aldehyde dehydrogenase from Clostridium beijerinckii NRRL B592.

    Yan, R T; Chen, J S

    1990-01-01

    Acetaldehyde and butyraldehyde are substrates for alcohol dehydrogenase in the production of ethanol and 1-butanol by solvent-producing clostridia. A coenzyme A (CoA)-acylating aldehyde dehydrogenase (ALDH), which also converts acyl-CoA to aldehyde and CoA, has been purified under anaerobic conditions from Clostridium beijerinckii NRRL B592. The ALDH showed a native molecular weight (Mr) of 100,000 and a subunit Mr of 55,000, suggesting that ALDH is dimeric. Purified ALDH contained no alcohol...

  14. Anaerobic regulation of the adhE gene, encoding the fermentative alcohol dehydrogenase of Escherichia coli.

    Leonardo, M R; Cunningham, P.R.; Clark, D P

    1993-01-01

    The regulation of the adhE gene, which encodes the trifunctional fermentative acetaldehyde-alcohol dehydrogenase of Escherichia coli, was investigated by the construction of gene fusions and by two-dimensional protein gel electrophoresis. Both operon and protein fusions of adhE to lacZ were induced 10- to 20-fold by anaerobic conditions, and both fusions were repressed by nitrate, demonstrating that regulation is at the level of transcription. Nitrate repression of phi (adhE-lacZ) expression,...

  15. Modeling diauxic glycolytic oscillations in yeast

    Hald, Bjørn Olav; Sørensen, Preben Graae

    2010-01-01

    investigations of central metabolism dynamics of yeast cells. We have previously proposed a model for the open system comprised of the primary fermentative reactions in yeast that quantitatively describes the oscillatory dynamics. However, this model fails to describe the transient behavior of metabolic....... Experimental and computational results strongly suggest that regulation of acetaldehyde explains the observed behavior. We have extended the original model with regulation of pyruvate decarboxylase, a reversible alcohol dehydrogenase, and drainage of pyruvate. Using the method of time rescaling in the extended...

  16. Biomass process handbook

    1983-01-01

    Descriptions are given of 42 processes which use biomass to produce chemical products. Marketing and economic background, process description, flow sheets, costs, major equipment, and availability of technology are given for each of the 42 processes. Some of the chemicals discussed are: ethanol, ethylene, acetaldehyde, butanol, butadiene, acetone, citric acid, gluconates, itaconic acid, lactic acid, xanthan gum, sorbitol, starch polymers, fatty acids, fatty alcohols, glycerol, soap, azelaic acid, perlargonic acid, nylon-11, jojoba oil, furfural, furfural alcohol, tetrahydrofuran, cellulose polymers, products from pulping wastes, and methane. Processes include acid hydrolysis, enzymatic hydrolysis, fermentation, distillation, Purox process, and anaerobic digestion.

  17. Enhanced Acid/Base Catalysis in High Temperature Liquid Water

    Xiu Yang LU; Qi JING; Zhun LI; Lei YUAN; Fei GAO; Xin LIU

    2006-01-01

    Two novel and environmentally benign solvent systems, organic acids-enriched high temperature liquid water (HTLW) and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW.

  18. A DFT study on the Cu (1 1 1) surface for ethyl acetate synthesis from ethanol dehydrogenation

    Li Ruzhen; Zhang Minhua [Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University R and D Center for Petrochemical Technology, Tianjin (China); Yu Yingzhe, E-mail: lrz1699@126.com [Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University R and D Center for Petrochemical Technology, Tianjin (China)

    2012-07-01

    Copper-based catalysts have shown excellent catalytic performances. Despite extensive studies in the field, the microscopic mechanism of ethanol dehydrogenation to ethyl acetate (EA) on Cu-based catalysts remains controversial. Aiming to provide insight into the catalytic roles of Cu, density functional theory (DFT) calculations have been performed to study the elementary reactions involved in ethanol dehydrogenation to EA on Cu surfaces. In this work, the adsorption properties of ethanol, ethoxy, acetaldehyde, acetyl and EA on the Cu (1 1 1) catalyst surface were investigated. Based on two pathways, many transition states involved are located. The results show that the route proposed by Colley is more likely to happen.

  19. Teores de compostos orgânicos em cachaças produzidas na região norte fluminense - Rio de Janeiro Organic compounds contents in cachaças produced in the northern Rio de Janeiro State - RJ

    Leandro Marelli de Souza

    2009-01-01

    Full Text Available This work aimed to quantify some organic compounds in "cachaças" (sugar cane spirit. The ethyl alcohol was quantified by densimetry, after distillation. The acetic acid, methyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, isoamyl alcohol (mixture of 2-methyl-butyl and 3-methyl-butyl, ethyl acetate and acetaldehyde were determined by gas chromatography; and the furfural, 5-hydroxy-methylfurfural and acrolein by high efficiency liquid chromatography. From the 30 samples analyzed, 63.3% showed non-conformity with national legislation regarding at least one of the analyzed components.

  20. Estimation of the Accuracy of Method for Quantitative Determination of Volatile Compounds in Alcohol Products

    Charepitsa, S V; Zadreyko, Y V; Sytova, S N

    2016-01-01

    Results of the estimation of the precision for determination volatile compounds in alcohol-containing products by gas chromatography: acetaldehyde, methyl acetate, ethyl acetate, methanol, isopropyl alcohol, propyl alcohol, isobutyl alcohol, butyl alcohol, isoamyl alcohol are presented. To determine the accuracy, measurements were planned in accordance with ISO 5725 and held at the gas chromatograph Crystal-5000. Standard deviation of repeatability, intermediate precision and their limits are derived from obtained experimental data. The uncertainty of the measurements was calculated on the base of an "empirical" method. The obtained values of accuracy indicate that the developed method allows measurement uncertainty extended from 2 to 20% depending on the analyzed compound and measured concentration.

  1. Levels and sources of volatile organic compounds including carbonyls in indoor air of homes of Puertollano, the most industrialized city in central Iberian Peninsula. Estimation of health risk.

    Villanueva, Florentina; Tapia, Araceli; Amo-Salas, Mariano; Notario, Alberto; Cabañas, Beatriz; Martínez, Ernesto

    2015-08-01

    Twenty nine organic air pollutants including carbonyl compounds, alkanes, aromatic hydrocarbons and terpenes were measured in the indoor environment of different houses together with the corresponding outdoor measurements in Puertollano, the most industrialized city in central Iberian Peninsula. VOCs were sampled during 8 weeks using Radiello(®) passive samplers, and a questionnaire on potential VOCs sources was filled out by the occupants. The results show that formaldehyde and hexanal was the most abundant VOCs measured in indoor air, with a median concentration of 55.5 and 46.4μgm(-3), respectively followed by butanal (29.1μgm(-3)), acetone (28.4μgm(-3)) and acetaldehyde (21.4μgm(-3)). After carbonyls, n-dodecane (13.1μgm(-3)) and terpenes (α-pinene, 13.4μgm(-3) and limonene, 13.4μgm(-3)) were the compounds with higher median concentrations. The indoor/outdoor (I/O) ratios demonstrated that sources in the indoor environment are prevailing for most of the investigated VOCs especially for limonene, α-pinene, hexanal, formaldehyde, pentanal, acetaldehyde, o-xylene, n-dodecane and acetone with I/O ratio >6. Multiple linear regressions were applied to investigate the indoor VOC determinants and Spearman correlation coefficients were used to establish common sources between VOCs. Finally, the lifetime cancer risk associated to formaldehyde, acetaldehyde and benzene exposure was estimated and they varied from 7.8×10(-5) to 4.1×10(-4) for formaldehyde, from 8.6×10(-6) to 3.5×10(-5) for acetaldehyde and from 2.0×10(-6) to 1.5×10(-5) for benzene. For formaldehyde, the attributed risk in most sampled homes was two orders of magnitude higher than the one (10(-6)) proposed as acceptable by risk management bodies. PMID:26025206

  2. Aldehyde Dehydrogenase 2 Knockout Accentuates Ethanol-Induced Cardiac Depression: Role of Protein Phosphatases

    Ma, Heng; Byra, Emily A.; Yu, Lu; Hu, Nan; Kitagawa, Kyoko; Nakayama, Keiichi I.; Kawamoto, Toshihiro; Ren, Jun

    2010-01-01

    Alcohol consumption leads to myocardial contractile dysfunction possibly due to the toxicity of ethanol and its major metabolite acetaldehyde. This study was designed to examine the influence of mitochondrial aldehyde dehydrogenase-2 (ALDH2) knockout (KO) on acute ethanol exposure-induced cardiomyocyte dysfunction. Wild-type (WT) and ALDH2 KO mice were subjected to acute ethanol (3 g/kg, i.p.) challenge and cardiomyocyte contractile function was assessed 24 hrs later using an IonOptix® edge-d...

  3. Regulation of cytochrome P450 2e1 expression by ethanol: role of oxidative stress-mediated pkc/jnk/sp1 pathway

    Jin, M; Ande, A; Kumar, A.; Kumar, S.

    2013-01-01

    CYP2E1 metabolizes ethanol leading to production of reactive oxygen species (ROS) and acetaldehyde, which are known to cause not only liver damage but also toxicity to other organs. However, the signaling pathways involved in CYP2E1 regulation by ethanol are not clear, especially in extra-hepatic cells. This study was designed to examine the role of CYP2E1 in ethanol-mediated oxidative stress and cytotoxicity, as well as signaling pathways by which ethanol regulates CYP2E1 in extra-hepatic ce...

  4. Threshold photoelectron spectroscopy and photoionization total ion yield spectroscopy of simple organic acids, aldehydes, ketones and amines

    We have initiated a research program to investigate the ionization behavior of some simple organic molecules containing the carboxyl group (R2C=O), where R could be H, OH, NH2, or CH3 or other aliphatic or aromatic carbon groups, using threshold photoelectron spectroscopy and photoionization total ion yield spectroscopy. We report here on the simplest organic acid, formic acid, and two simple aldehydes: acetaldehyde and the simplest unsaturated aldehyde, 2-propenal (acrolein). The objective of this study was to characterize the valence cationic states of these molecules with vibrational structural resolution.

  5. Controllable synthesis of highly ordered Ag nanorod arrays by chemical deposition method

    Highly ordered Ag nanorod arrays were successfully fabricated using a simple chemical deposition method with the assistance of porous alumina membrane (PAM) template. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ag+ ions in the PAM nanochannels were reduced by acetaldehyde reagent and resulting in the formation of rod array structures. It is found that the diameter of the Ag nanorods is determined by the PAM template, and the length of the Ag nanorods is depended on the reaction temperature. The growth mechanism of the Ag nanorod arrays is investigated in the study.

  6. Role of Transcription Factors in Steatohepatitis and Hypertension after Ethanol: The Epicenter of Metabolism

    Rais A. Ansari

    2016-06-01

    Full Text Available Chronic alcohol consumption induces multi-organ damage, including alcoholic liver disease (ALD, pancreatitis and hypertension. Ethanol and ethanol metabolic products play a significant role in the manifestation of its toxicity. Ethanol metabolizes to acetaldehyde and produces reduced nicotinamide adenine dinucleotide (NADH by cytosolic alcohol dehydrogenase. Ethanol metabolism mediated by cytochrome-P450 2E1 causes oxidative stress due to increased production of reactive oxygen species (ROS. Acetaldehyde, increased redox cellular state and ROS activate transcription factors, which in turn activate genes for lipid biosynthesis and offer protection of hepatocytes from alcohol toxicity. Sterol regulatory element binding proteins (SREBPs and peroxisome proliferator activated-receptors (PPARs are two key lipogenic transcription factors implicated in the development of fatty liver in alcoholic and non-alcoholic steatohepatitis. SREBP-1 is activated in the livers of chronic ethanol abusers. An increase in ROS activates nuclear factor erythroid-2-related factor-2 (Nrf2 and hypoxia inducible factor (HIF to provide protection to hepatocytes from ethanol toxicity. Under ethanol exposure, due to increased gut permeability, there is release of gram-negative bacteria-derived lipopolysaccharide (LPS from intestine causing activation of immune response. In addition, the metabolic product, acetaldehyde, modifies the proteins in hepatocyte, which become antigens inviting auto-immune response. LPS activates macrophages, especially the liver resident macrophages, Kupffer cells. These Kupffer cells and circulating macrophages secrete various cytokines. The level of tumor necrosis factor-α (TNFα, interleukin-1beta (IL-1β, IL-6, IL-8 and IL-12 have been found elevated among chronic alcoholics. In addition to elevation of these cytokines, the peripheral iron (Fe2+ is also mobilized. An increased level of hepatic iron has been observed among alcoholics. Increased ROS

  7. Effects of potassium sorbate and Lactobacillus plantarum MTD1 on production of ethanol and other volatile organic compounds in corn silage

    Hafner, Sasha D.; Windle, Michelle; Merrill, Caitlyn;

    2015-01-01

    evaluate the effect of additives on production of nine silage VOC in corn silage, including compounds thought to contribute to poor air quality or affect feed intake (alcohols: methanol, ethanol, 1-propanol; esters: methyl acetate, ethyl acetate, ethyl lactate; and aldehydes: acetaldehyde, valeraldehyde...... results provide additional evidence that potassium sorbate is an effective additive for reducing production of ethanol and ethyl esters in corn silage. Combining potassium sorbate with L. plantarum may provide additional benefits, although the persistence of this effect for silages with higher VOC...

  8. DNA adducts-chemical addons

    T. R. Rajalakshmi; N AravindhaBabu; Shanmugam, K. T.; Masthan, K. M. K.

    2015-01-01

    DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde). This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could b...

  9. Eletroxidação do etanol em eletrodos de Ti/IrO2

    Fidelis Carlos H.V.

    2001-01-01

    Full Text Available It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed is presented.

  10. Development of metal cation compound-loaded S-doped TiO2 photocatalysts having a rutile phase under visible light

    Ohno, T; Murakami, N.; Tsubota, T.; Nishimura, H.

    2008-01-01

    We have synthesized S (S4+)-doped TiO2 photocatalysts having a rutile phase. Rutile S-doped TiO2 photocatalysts loaded with metal ion compounds (Fe3+, Rh3+, Cu2+, Co3+, Ni2+, Cr3+) have also been prepared (S-doped TiO2-Mn+). The metal ions were adsorbed on the surfaces of S-doped TiO2 nanoparticles by impregnation methods (IM) or photodeposition methods (PH). The photocatalytic activities of S-doped TiO2 for oxidation of acetaldehyde in gas phase were drastically improved after adsorbing trea...

  11. CHANGES IN VOLATILE COMPOSITION OF KRALJEVINA WINES BY CONTROLLED MALOLACTIC FERMENTATION

    Ana JEROMEL

    2008-11-01

    Full Text Available The effect of malolactic fermentation (MLF on the volatile composition of white wines made from autochtonous grape variety Kraljevina was studied by inoculation with selected lactic acid bacteria. At the end of malolactic fermentation, after the decomposition of the malic acid present in wine the non volatile compounds were analyzed by HPLC, while volatile compounds were analyzed by gas chromatography. All wines were also sensory analyzed. Results showed changes in acetaldehyde, some higher alcohols, ethyl esters, free and bound monoterpenes and some organic acids that contribute to enhance the sensory properties and quality of Kraljevina wines that underwent malolactic fermentation.

  12. Physical and toxic properties of hazardous chemicals regularly stored and transported in the vicinity of nuclear installations

    This report gives a compilation of data based on information assembled by the US Nuclear Regulatory Commission and completed by the Safety and Reliability Directorate of the UK AEA, the Dutch Reactor Safety Commission, the French Atomic Energy Commission, and the CSNI Secretariat. Data sheets for a large number of hazardous chemicals are presented (from acetaldehyde to xylene), giving details of their physical and toxic properties such as: molecular weight, boiling point, vapor density, heat of vaporization, toxic concentration in air, flammability limits, toxic effects, vapor pressure data, etc.

  13. R\\'eduction de la nuisance olfactive par oxydation photocatalytique

    Vincent, Guillaume

    2009-01-01

    Heterogeneous photocatalysis is an interesting alternative for the purification, decontamination and smell abatment of air. In the present work, the photocatalytic oxidation of 2-butanone (MEK : methyl ethyle ketone) is investigated, this low molecular mass product being the source of serious smell pollution. The influence of light and of the pollutant concentration were investigated in an annular photoreactor. As most VOC's, the degradation rate of MEK follows a Langmuir-Hinshelwood type law. Intermediate products were analysed by GC-MD ; acetaldehyde is the dominant byproduct of the photocatalytic oxidation.

  14. Catalytic selective oxidation or oxidative functionalization of methane and ethane to organic oxygenates

    2010-01-01

    Selective oxidation or oxidative functionalization of methane and ethane by both homogeneous and heterogeneous catalysis is presented concerning: (1) selective oxidation of methane and ethane to organic oxygenates by hydrogen peroxide in a water medium in the presence of homogeneous osmium catalysts, (2) selective oxidation of methane to formaldehyde over highly dispersed iron and copper heterogeneous catalysts, (3) selective oxidation of ethane to acetaldehyde and formaldehyde over supported molybdenum catalysts, and (4) oxidative carbonylation of methane to methyl acetate over heterogeneous catalysts containing dual sites of rhodium and iron.

  15. Lipid peroxidation in ethanol poisoning: a critical reconsideration.

    Dianzani, M U

    1985-01-01

    Evidence for the existence of increased lipid peroxidation in the liver after ethanol administration to rats is discussed. A criticism of the methods used to measure lipid peroxidation is also given. Most authors who are in favour of the presence of lipid peroxidation after ethanol have used the detection of thiobarbituric acid (TBA)-reacting substances as a measure of lipid peroxidation. This test is not entirely satisfactory, because: (1) it is not specific; (2) it mostly measures malonaldehyde, a substance of low toxicity, following a 1-2 hr incubation time; (3) several aldehydes produced during lipid peroxidation do not react with TBA. However, it is now clear that the aldehydes produced during lipid peroxidation are actively metabolized by homogenates, so differences in catabolism may influence the result of a TBA test. Measurement of the diene conjugation band, the other test usually used to detect lipid peroxidation, produces information only on the presence of dienes at a given moment, but does not give any information on the production or decomposition rates of such dienes. Thus differences in production or decomposition kinetics may mask the results. Notwithstanding these criticisms, most of the evidence at present is in favour of some involvement of lipid peroxidation in ethanol intoxication. One hypothesis is that of the direct impact of ethanol-derived free radicals. Another is that ethanol provokes the formation of oxygen free radical species, which can start lipid peroxidation either directly, or by exhausting anti-oxidant substances in the cell so as to change the balance in favour of increased peroxidation. Finally, a third hypothesis is that acetaldehyde, the main product of ethanol oxidation, is able to stimulate lipid peroxidation, possibly through the formation of free radicals, or depletion of levels of antioxidant substances. Experiments consisting of measuring total glutathione (GSH and GSSG) during lipid peroxidation stimulated by ethanol

  16. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 3, Revision 2 (FGE.03Rev2): Acetals of branched- and straight-chain aliphatic saturated primary alcohols and branched- and straight-chain saturated or unsaturated

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate one flavouring substance, acetaldehyde ethyl isopropyl acetal [FL-no: 06.137], structurally related to the 58 flavouring substances in the Flavouring Group...... structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded as for the other already evaluated substances that the substance [FL-no: 06.137] do not give rise to safety concern at its level of dietary...

  17. Determination of carbonyl compounds in air by HPLC

    A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetone+acrolein. Three different types of samples (rural, urban, petrol emission) were successfully analyzed

  18. Radiolysis of aqueous-ethanolic solution of tryptophan

    The effect of ethanol on radiation stability of tryptophan during γ-irradiation of its aqueous solutions was investigated. In comparison with radiation losses of tryptophan irradiated in pure water, the losses in aqueous-ethanolic solutions are considerably higher and they increase with increasing ethanol concentration. Basic radiation products of tryptophan formed on irradiation of its aqueous-ethanolic solutions in consequence of the reaction of tryptophan with acetaldehyde as the main product of radiolysis of ethanol were followed by paper electrophoresis. (author)

  19. Urban Air Pollution from Ethanol (E85) in the Presence of Aqueous Aerosols and Fog

    Ginnebaugh, D. L.; Jacobson, M. Z.

    2010-12-01

    This is a study to examine the effect of ethanol (E85) versus gasoline on urban air pollution in the presence of aqueous aerosols and fog. In previous work, we analyzed the temperature-dependence of ethanol and gasoline exhaust chemistry and its impact on urban air pollution considering only gas-phase chemistry. We used the near-explicit Master Chemical Mechanism (MCM, version 3.1, LEEDS University) with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate explicit chemistry. The MCM has over 13,500 organic reactions and 4,600 species. SMVGEAR II is a sparse-matrix Gear solver that reduces the computation time significantly while maintaining any specified accuracy. We found that the average ozone concentrations through the range of temperatures tested could be higher with E85 than with gasoline by up to 8 parts per billion volume (ppbv) at room temperature but much higher at cold temperatures and low sunlight (winter conditions) for a region with a high nitrogen oxide (NOx) to non-methane organic gases (NMOG) ratio. We also found that the solution to chemistry in a 3-D urban airshed model was practical. We now extend our study to include aqueous chemistry in the presence of aerosols and fog. We combine the Chemical Aqueous Phase Radical Mechanism, CAPRAM 3.0 with the MCM 3.1 and gas-particle transfer in box model calculations. CAPRAM treats aqueous phase chemistry among 390 species and 829 reactions (including 51 gas-to-aqueous phase reactions). We investigate the impact aqueous reactions have on unburned ethanol and acetaldehyde mixing ratios in the atmosphere in particular because acetaldehyde is an ozone precursor and carcinogen, and aqueous oxidation has potential to speed the conversion of unburned ethanol to acetaldehyde. Acetaldehyde also forms acetic acid in aqueous solution. Acetic acid vapor is an eye, nose, and lung irritant, so both species contribute negatively to human health. We look at the impact of aerosol

  20. Effects of gamma irradiation on chemical and sensory evaluation of Cabernet Sauvignon wine

    Cabernet Sauvignon wines received gamma irradiation doses of 0, 0.6, 1.2 or 2.4 KGy and were stored at 21°C for up to 18 months. As radiation dose and storage time increased, total anthocyanin concentration decreased, while color density, hue and color age increased. Acetaldehyde concentration increased with increasing radiation dose and decreased as storage time increased. Sensory evaluation indicated no difference in color or astringency, but off-flavors were detected in wines given a 2.4 KGy dose. Use of gamma irradiation to rapid age Cabernet Sauvignon wines did not appear to be feasible

  1. Micro-aerobics: when rice plants lose their resistance against oxygen

    Reuss, J.; Harren, F. J. M.

    2008-10-01

    Photoacoustic determination of ethane, ethanol and acetaldehyde releases from 14 d old rice seedlings leads to the conclusion that rice seedlings start suffering significant lipid peroxidation under micro-aerobic conditions. To produce micro-aerobic conditions in otherwise normal atmospheres, the oxygen concentration has been reduced to a value between 0.3 and 0.05% (v/v). The defense of the rice seedlings against oxygenic radicals becomes insufficient under these almost anaerobic conditions. The findings presented here are relevant for the clarification of what causes non-survival of rice seedlings under prolonged submergence. Dedicated to Professor Anna Giardini, University of Rome, at her retirement.

  2. Micro-aerobics: when rice plants lose their resistance against oxygen

    Reuss, J; Harren, F J M [Life Science Trace Gas Exchange Facility, Department of Molecular and Laser Physics, University of Nijmegen, Toernooiveld I, 6525 ED Nijmegen (Netherlands)], E-mail: J.Reuss@science.ru.nl

    2008-10-15

    Photoacoustic determination of ethane, ethanol and acetaldehyde releases from 14 d old rice seedlings leads to the conclusion that rice seedlings start suffering significant lipid peroxidation under micro-aerobic conditions. To produce micro-aerobic conditions in otherwise normal atmospheres, the oxygen concentration has been reduced to a value between 0.3 and 0.05% (v/v). The defense of the rice seedlings against oxygenic radicals becomes insufficient under these almost anaerobic conditions. The findings presented here are relevant for the clarification of what causes non-survival of rice seedlings under prolonged submergence.

  3. Cloning and sequencing of pyruvate decarboxylase (PDC) genes from bacteria and uses therefor

    Maupin-Furlow, Julie A [Gainesville, FL; Talarico, Lee Ann [Gainesville, FL; Raj, Krishnan Chandra [Tamil Nadu, IN; Ingram, Lonnie O [Gainesville, FL

    2008-02-05

    The invention provides isolated nucleic acids molecules which encode pyruvate decarboxylase enzymes having improved decarboxylase activity, substrate affinity, thermostability, and activity at different pH. The nucleic acids of the invention also have a codon usage which allows for high expression in a variety of host cells. Accordingly, the invention provides recombinant expression vectors containing such nucleic acid molecules, recombinant host cells comprising the expression vectors, host cells further comprising other ethanologenic enzymes, and methods for producing useful substances, e.g., acetaldehyde and ethanol, using such host cells.

  4. Desidratação de etanol sobre material nanoestruturado do tipo LaSBA-15 Ethanol dehydration over LaSBA-15 nanostrutured material

    Geraldo E. Luz Jr

    2010-01-01

    Full Text Available La-incorporated SBA-15 mesopourous molecular sieves (LaSBA-15 were directly synthesized with aim to convert ethanol to ethylene. The samples were characterized by XRD, XRF, nitrogen sorption and acidity, by thermodesorption of n-buthylamine. The results have indicated that all the samples have showed high ordered mesostructure with a large average pore size, and that the lanthanum incorporation has caused an increase in the acidity of the SBA-15. The LaSBA-15 samples have improved, with low deactivation rate, the conversion of the ethanol to water, ether, acetaldehyde and ethylene. In addition, they have increased the ethylene selectivity.

  5. The sugar model: catalysis by amines and amino acid products

    Weber, A. L.

    2001-01-01

    Ammonia and amines (including amino acids) were shown to catalyze the formation of sugars from formaldehyde and glycolaldehyde, and the subsequent conversion of sugars to carbonylcontaining products under the conditions studied (pH 5.5 and 50 degrees C). Sterically unhindered primary amines were better catalysts than ammonia, secondary amines, and sterically hindered primary amines (i.e. alpha-aminoisobutyric acid). Reactions catalyzed by primary amines initially consumed formaldehyde and glycolaldehyde about 15-20 times faster than an uncatalyzed control reaction. The amine-catalyzed reactions yielded aldotriose (glyceraldehyde), ketotriose (dihydroxyacetone), aldotetroses (erythrose and threose), ketotetrose (erythrulose), pyruvaldehyde, acetaldehyde, glyoxal, pyruvate, glyoxylate, and several unindentified carbonyl products. The concentrations of the carbonyl products, except pyruvate and ketotetrose, initially increased and then declined during the reaction, indicating their ultimate conversion to other products (like larger sugars or pyruvate). The uncatalyzed control reaction yielded no pyruvate or glyoxylate, and only trace amounts of pyruvaldehyde, acetaldehyde and glyoxal. In the presence of 15 mM catalytic primary amine, such as alanine, the rates of triose and pyruvaldehyde of synthesis were about 15-times and 1200-times faster, respectively, than the uncatalyzed reaction. Since previous studies established that alanine is synthesized from glycolaldehyde and formaldehyde via pyruvaldehyde as its direct precursor, the demonstration that the alanine catalyzes the conversion of glycolaldehyde and formaldehyde to pyruvaldehyde indicates that this synthetic pathway is capable of autocatalysis. The relevance of this synthetic process, named the Sugar Model, to the origin of life is discussed.

  6. Sugars as tobacco ingredient: Effects on mainstream smoke composition.

    Talhout, Reinskje; Opperhuizen, Antoon; van Amsterdam, Jan G C

    2006-11-01

    Sugars are natural tobacco components, and are also frequently added to tobacco during the manufacturing process. This review describes the fate of sugars during tobacco smoking, in particular the effect of tobacco sugars on mainstream smoke composition. In natural tobacco, sugars can be present in levels up to 20 wt%. In addition, various sugars are added in tobacco manufacturing in amounts up to 4 wt% per sugar. The added sugars are usually reported to serve as flavour/casing and humectant. However, sugars also promote tobacco smoking, because they generate acids that neutralize the harsh taste and throat impact of tobacco smoke. Moreover, the sweet taste and the agreeable smell of caramelized sugar flavors are appreciated in particular by starting adolescent smokers. Finally, sugars generate acetaldehyde, which has addictive properties and acts synergistically with nicotine in rodents. Apart from these consumption-enhancing pyrolysis products, many toxic (including carcinogenic) smoke compounds are generated from sugars. In particular, sugars increase the level of formaldehyde, acetaldehyde, acetone, acrolein, and 2-furfural in tobacco smoke. It is concluded that sugars in tobacco significantly contribute to the adverse health effects of tobacco smoking. PMID:16904804

  7. Effect of calcination temperature on the photocatalytic reduction and oxidation processes of hydrothermally synthesized titania nanotubes.

    Viayan, B.; Dimitrijevic, N. M.; Rajh, T.; Gray, K.; Northwestern Univ.

    2010-08-05

    Titania nanotubes having diameters 8 to 12 nm and lengths of 50-300 nm were prepared using a hydrothermal method. Further, the titania nanotubes were calcined over the temperature range 200-800 C in order to enhance their photocatalytic properties by altering their morphology. The calcined titania nanotubes were characterized by using X-ray diffraction and surface area analysis and their morphological features were studied by scanning and transmission electron microscopy. Nanotubes calcined at 400 C showed the maximum extent of photocatalyitc reduction of carbon dioxide to methane, whereas samples calcined at 600 C produced maximum photocatalytic oxidation of acetaldehyde. Electron paramagnetic resonance (EPR) spectroscopy was used to interrogate the effects of nanotube structure on the charge separation and trapping as a function of calcination temperature. EPR results indicated that undercoordinated titania sites are associated with maximum CO{sub 2} reduction occurring in nanotubes calcined at 400 C. Despite the collapse of the nantube structure to form nanorods and the concomitant loss of surface area, the enhanced charge separation associated with increased crystallinity promoted high rates of oxidation of acetaldehyde in titania materials calcined at 600 C. These results illustrate that calcination temperature allows us to tune the morphological and surface features of the titania nanostructures for particular photocatalytic reactions.

  8. Results of the California Healthy Homes Indoor Air Quality Study of 2011-2013: impact of natural gas appliances on air pollutant concentrations.

    Mullen, N A; Li, J; Russell, M L; Spears, M; Less, B D; Singer, B C

    2016-04-01

    This study was conducted to assess the current impact of natural gas appliances on air quality in California homes. Data were collected via telephone interviews and measurements inside and outside of 352 homes. Passive samplers measured time-resolved CO and time-integrated NOX , NO2 , formaldehyde, and acetaldehyde over ~6-day periods in November 2011 - April 2012 and October 2012 - March 2013. The fraction of indoor NOX and NO2 attributable to indoor sources was estimated. NOX , NO2 , and highest 1-h CO were higher in homes that cooked with gas and increased with amount of gas cooking. NOX and NO2 were higher in homes with cooktop pilot burners, relative to gas cooking without pilots. Homes with a pilot burner on a floor or wall furnace had higher kitchen and bedroom NOX and NO2 compared to homes without a furnace pilot. When scaled to account for varying home size and mixing volume, indoor-attributed bedroom and kitchen NOX and kitchen NO2 were not higher in homes with wall or floor furnace pilot burners, although bedroom NO2 was higher. In homes that cooked 4 h or more with gas, self-reported use of kitchen exhaust was associated with lower NOX , NO2 , and highest 1-h CO. Gas appliances were not associated with higher concentrations of formaldehyde or acetaldehyde. PMID:25647016

  9. Study of the emission of low molecular weight organic compounds of various plants

    Biogenic hydrocarbons are known to act as important precursors in tropospheric photochemical ozone formation. Large uncertainties exist about the composition of the mix of volatile organic compounds, emitted by various plant species and the respective emission rates. The emission and deposition behavior of wheat plants, as far as C2 to C9 hydrocarbons (NMHC), formaldehyde, and acetaldehyde are concerned, was studied both in the field (BIATEX experimental site, Manndorf, Bavaria) and in the laboratory. Vertical flux rates of the different compounds ranged from -4 to +4 nmol C m-2 surface area s-1. Aldehydeemission showed a seasonal trend with high rates in spring and lower towards the end of the vegetation period. Ambient temperature appears to control only the flux of ethane, ethene, propane and propene, whereas acetaldehyde emission by wheat plants as well as by Norway spruce is controlled by light. Over a spruce canopy (BIATEX experimental site Schachtenau, Bayerischer Wald, national park, FRG) the 12 most abundant NMHC exhibited no distinct diurnal cycle, and only small differences in mixing ratios were detected between two heights (31 and 51 m) revealing that the impact of the canopy on the abundances of the non-terpenoid NMHCs present in the air above the canopy was small. Aldehyde mixing ratios above a spruce canopy, however, may significantly be influenced either by direct emission of aldehydes from spruce or by production of aldehydes during photochemical degradation of precursors. (orig.). 87 refs., 4 tabs., 25 figs

  10. Effects of 20 Selected Fruits on Ethanol Metabolism: Potential Health Benefits and Harmful Impacts.

    Zhang, Yu-Jie; Wang, Fang; Zhou, Yue; Li, Ya; Zhou, Tong; Zheng, Jie; Zhang, Jiao-Jiao; Li, Sha; Xu, Dong-Ping; Li, Hua-Bin

    2016-04-01

    The consumption of alcohol is often accompanied by other foods, such as fruits and vegetables. This study is aimed to investigate the effects of 20 selected fruits on ethanol metabolism to find out their potential health benefits and harmful impacts. The effects of the fruits on ethanol metabolism were characterized by the concentrations of ethanol and acetaldehyde in blood, as well as activities of alcohol dehydrogenase and acetaldehyde dehydrogenase in liver of mice. Furthermore, potential health benefits and harmful impacts of the fruits were evaluated by biochemical parameters including aspartate transaminase (AST), alanine transferase (ALT), malondialdehyde, and superoxide dismutase. Generally, effects of these fruits on ethanol metabolism were very different. Some fruits (such as Citrus limon (yellow), Averrhoa carambola, Pyrus spp., and Syzygium samarangense) could decrease the concentration of ethanol in blood. In addition, several fruits (such as Cucumis melo) showed hepatoprotective effects by significantly decreasing AST or ALT level in blood, while some fruits (such as Averrhoa carambola) showed adverse effects. The results suggested that the consumption of alcohol should not be accompanied by some fruits, and several fruits could be developed as functional foods for the prevention and treatment of hangover and alcohol use disorder. PMID:27043608

  11. Ag@graphene oxide nanocomposite as an efficient visible-light plasmonic photocatalyst for the degradation of organic pollutants: A facile green synthetic approach

    We report a simple and effective supercritical route to decorate silver nanoparticles (Ag NPs) on graphene oxide (GO) using a commonly available and non-toxic glucose as a reducing agent. Transmission electron microscopy and energy-dispersive X-ray analysis confirmed that Ag NPs of size around 8–20 nm were coated on the GO surface under optimized experimental condition. Ag NPs on the GO surface were predominantly spherical in shape and well dispersed. The experimental results proved that the as-synthesized GO/Ag nanocomposite could be used as a highly efficient photocatalyst for the degradation of Rhodamine 123 dye and acetaldehyde under visible-light irradiation. The degradation results indicated that the photocatalytic performance of nanocomposite was greatly enhanced owing to the improved adsorption performance and separation efficiency of photo-generated carriers. The nanocomposite maintains a high level activity even after four times of recycle. Furthermore, the nanocomposite exhibited excellent antibacterial activity against gram-positive and gram-negative microorganisms. - Highlights: • Visible-light driven reusable photocatalyst. • Efficient degradation of Rhodamine 123 dye and acetaldehyde. • Excellent antibacterial activity. • Green synthetic approach using supercritical fluid. • New field of sustainable nanotechnology

  12. Experimental validation of concentration profiles in an HCCI engine, modelled by a multi-component kinetic mechanism: Outline for auto-ignition and emission control

    Machrafi, Hatim, E-mail: hatim-machrafi@enscp.f [UPMC Universite Paris 06, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); Universite de Liege, Thermodynamique des Phenomenes Irreversibles, 17, Allee du Six-Aout, 4000 Liege (Belgium)

    2010-10-15

    In order to contribute to the auto-ignition and emission control for Homogeneous Charge Compression Ignition (HCCI), a kinetic multi-component mechanism, containing 62 reactions and 49 species for mixtures of n-heptane, iso-octane and toluene is validated in this work, comparing for the concentration profiles of the fuel, the total hydrocarbons, O{sub 2}, CO{sub 2}, CO, acetaldehyde and iso-butene. These species are sampled during the combustion and quantified. For these measurements an automotive exhaust analyser, a gas chromatograph, coupled to a mass spectrometer and a flame ionisation detector are used, depending on the species to be measured. The fuel, total hydrocarbons, O{sub 2}, CO{sub 2}, iso-butene and acetaldehyde showed a satisfactory quantitative agreement between the mechanism and the experiments. Both the experiments and the modelling results showed the same formation behaviour of the different species. An example is shown of how such a validated mechanism can provide for a set of information of the behaviour of the auto-ignition process and the emission control as a function of engine parameters.

  13. Acetate causes alcohol hangover headache in rats.

    Christina R Maxwell

    Full Text Available BACKGROUND: The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. METHODS: We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. RESULTS: Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia, followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity. DISCUSSION: Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction.

  14. Ginsenoside-free molecules from steam-dried ginseng berry promote ethanol metabolism: an alternative choice for an alcohol hangover.

    Lee, Do Ik; Kim, Seung Tae; Lee, Dong Hoon; Yu, Jung Min; Jang, Su Kil; Joo, Seong Soo

    2014-07-01

    Ethanol metabolism produces harmful compounds that contribute to liver damage and cause an alcohol hangover. The intermediate metabolite acetaldehyde is responsible for alcohol hangover and CYP2E1-induced reactive oxygen species damage liver tissues. In this study, we examined whether ginsenoside-free molecules (GFMs) from steam-dried ginseng berries promote ethanol metabolism and scavenge free radicals by stimulating primary enzymes (alcohol dehydrogenase, aldehyde dehydrogenase, CYP2E1, and catalase) and antioxidant effects using in vitro and in vivo models. The results revealed that GFM effectively scavenged 2,2-diphenyl-1-picrylhydrazyl hydrate radicals and hydroxyl radicals. Notably, GFM significantly enhanced the expression of primary enzymes within 2 h in HepG2 cells. GFM clearly removed the consumed ethanol and significantly reduced the level of acetaldehyde as well as enhancement of primary gene expression in BALB/c mice. Moreover, GFM successfully protected HepG2 cells from ethanol attack. Of the major components identified in GFM, it was believed that linoleic acid was the most active ingredient. Based on these findings, we conclude that GFM holds promise for use as a new candidate for ethanol metabolism and as an antihangover agent. PMID:24962619

  15. Determination of direct photolysis rate constants and OH radical reactivity of representative odour compounds in brewery broth using a continuous flow-stirred photoreactor

    Jürgens, Marion; Jacob, Fritz; Ekici, Perihan; Friess, Albrecht; Parlar, Harun

    A method based on photolysis was developed for the appropriate treatment of organic pollutants in air exhausting from breweries upon wort decoction, and thereby causing smell nuisance. A continuous flow stirred photoreactor was built-up exclusively, allowing OH radicals to react with selected odorous compounds contained in exhaust vapours, such as: 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, 3-methyl-1-butanol, n-hexanal, 2-methylbutyl isobutyrate, 2-undecanone, phenyl acetaldehyde, myrcene, limonene, linalool, humulene, dimethylsulphide, and dimethyltrisulphide. These substances were quantified in brewery broth before and after UV irradiation using high-resolution gas chromatography-mass spectrometry (HRGC-MS). For odour analysis, high-resolution gas chromatography-flame ionisation detection (HRGC-FID) coupled with sensory methods was used. Determined quantum yields of about 10 -3 for phenyl acetaldehyde, myrcene, and humulene pointed out that direct photolysis contributed to their decay. Quantum yields of below 10 -4 for the other substances indicated that UV irradiation did not contribute significantly to their degradation processes. Hydroxyl radical reaction rate constants and Henry constants of organic compounds were also measured. Substances accompanied with low Henry constants converted rapidly, whereas those with higher ones, relatively slowly. Determined aroma values concluded that after UV-H 2O 2 treatment, only dimethylsulphide and myrcene remained as important odorous compounds, but in significantly reduced concentrations. The UV-H 2O 2 treatment of brewery broth has been proved effective to reduce smell-irritating substances formed upon wort decoction.

  16. Efeito da presença e concentração de compostos carbonílicos na qualidade de vinhos Effects of carbonylic compound presence and concentration on wine quality

    Luciana C. de Azevêdo

    2007-01-01

    Full Text Available Studies on identification of compounds that make up the aroma and flavor in wines involve research evaluating mainly the influence of terpenes, esters, lactones and alcohols upon these sensory characteristics. However, carbonylic compounds (CC play an important role concerning the substances that impact aroma to these drinks. Their origin is reported to be linked to the grape's chemical composition, must fermentation or micro-oxidation occurring during storage in barrels. Some CCs, like E-ionone, E-damascenone, siryngaldehyde, can contribute a pleasant aroma and improve the wine quality whereas others are responsible for unpleasant characteristics (acetaldehyde, furfural, 5-hydroxy-methyl furfural, diacetil, E-non-2-enal, etc. A fraction of CCs present is associated with bisulfite ions in the form of hydroxyalkylsulfonic acids. Some of them are stable and play an important role in determining wine quality. The reaction involving the formation of this aduct commonly occurs with CCs of low molar mass, such as formaldehyde and acetaldehyde. The reaction involving CCs with more than three carbon atoms demands further studies.

  17. Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

    M. K. Kajos

    2015-04-01

    Full Text Available Proton transfer reaction mass spectrometry (PTR-MS and gas chromatography mass spectrometry GC-MS allow real-time measurements of various atmospheric volatile organic compounds (VOC. By taking parallel measurements in ambient conditions, two PTR-MSs and two GC-MSs were studied for their ability to measure methanol, acetaldehyde, acetone, benzene and toluene. The measurements were conducted at a rural boreal forest site in southern Finland between 13 April and 14 May 2012. This paper presents correlations and possible biases between the concentrations measured using the four instruments. This paper presents correlations and possible biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds, while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively. For some compounds, notably for methane, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90. The systematic difference arises as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50–100% in the methanol emissions measured by commonly used methods.

  18. Measurement of n-alkanals and hydroxyalkenals in biological samples.

    Holley, A E; Walker, M K; Cheeseman, K H; Slater, T F

    1993-09-01

    A modified method was developed to measure nM levels of a range of n-alkanals and hydroxyalkenals in biological samples such as blood plasma and tissue homogenates and also in Folch lipid extracts of these samples. Butylated hydroxytoluene (BHT) and desferrioxamine (Desferal) were added to samples to prevent artifactual peroxidation. Aldehydes were reacted with 1,3-cyclohexanedione (CHD), cleaned up by solid-phase extraction on a Sep-Pak C18 cartridge and the fluorescent decahydroacridine derivatives resolved by reverse-phase high-performance liquid chromatography (HPLC) with gradient elution. A wider range of aldehydes was detected in lipid extracts of plasma and liver homogenate compared to whole (unextracted) samples. Human plasma contained nM levels of acetaldehyde, propanal, butanal, pentanal, hexanal, and heptanal. 4-Hydroxynonenal (0.93 nmol/g) and alkanals with two to six carbons (up to 7.36 nmol/g) were detected in rat liver. Recovery of aldehydes added to whole plasma or to lipid extracts of plasma was dependent on carbon chain length, varying from 95% for acetaldehyde to 8% for decanal. Recovery from biological samples was significantly less than that of standards taken through the Sep-Pak clean-up procedure, suggesting that aldehydes can bind to plasma protein and lipid components. PMID:8406128

  19. Effect of variable power levels on the yield of total aerosol mass and formation of aldehydes in e-cigarette aerosols.

    Gillman, I G; Kistler, K A; Stewart, E W; Paolantonio, A R

    2016-03-01

    The study objective was to determine the effect of variable power applied to the atomizer of refillable tank based e-cigarette (EC) devices. Five different devices were evaluated, each at four power levels. Aerosol yield results are reported for each set of 25 EC puffs, as mass/puff, and normalized for the power applied to the coil, in mass/watt. The range of aerosol produced on a per puff basis ranged from 1.5 to 28 mg, and, normalized for power applied to the coil, ranged from 0.27 to 1.1 mg/watt. Aerosol samples were also analyzed for the production of formaldehyde, acetaldehyde, and acrolein, as DNPH derivatives, at each power level. When reported on mass basis, three of the devices showed an increase in total aldehyde yield with increasing power applied to the coil, while two of the devices showed the opposite trend. The mass of formaldehyde, acetaldehyde, and acrolein produced per gram of total aerosol produced ranged from 0.01 to 7.3 mg/g, 0.006 to 5.8 mg/g, and aerosols from specific devices, and were compared to estimated exposure from consumption of cigarettes, to occupational and workplace limits, and to previously reported results from other researchers. PMID:26743740

  20. Reaction of ethanol on oxidized and metallic cobalt surfaces

    Hyman, Matthew P.; Vohs, John M.

    2011-02-01

    The reaction of ethanol on metallic and oxidized cobalt surfaces was studied using temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) in order to determine the dependence of the reaction pathways on the cobalt oxidation state. The primary reaction for ethoxide species on metallic cobalt surfaces was decarbonylation producing CO, H 2 and carbon. This reaction was facile and occurred below 400 K. In contrast, CoO x surfaces which predominantly contained Co 2+ were selective for the dehydrogenation of ethoxide groups to produce acetaldehyde at 400 K. A fraction of the acetaldehyde molecules produced by this pathway were further oxidized to acetate which decomposed to produce CO 2 at 495 K. More highly oxidized Co surfaces that contained both CO 2+ and Co 3+ were active for the complete oxidation of ethanol producing CO, CO 2, and H 2O as the primary products. The insights that these results provide for understanding the mechanism of the steam reforming of ethanol on cobalt catalysts is discussed.

  1. TiO2-Impregnated Porous Silica Tube and Its Application for Compact Air- and Water-Purification Units

    Tsuyoshi Ochiai

    2015-09-01

    Full Text Available A simple, convenient, reusable, and inexpensive air- and water-purification unit including a one-end sealed porous amorphous-silica (a-silica tube coated with TiO2 photocatalyst layers has been developed. The porous a-silica layers were formed through outside vapor deposition (OVD. TiO2 photocatalyst layers were formed through impregnation and calcination onto a-silica layers. The resulting porous TiO2-impregnated a-silica tubes were evaluated for air-purification capacity using an acetaldehyde gas decomposition test. The tube (8.5 mm e.d. × 150 mm demonstrated a 93% removal rate for high concentrations (ca. 300 ppm of acetaldehyde gas at a single-pass condition with a 250 mL/min flow rate under UV irradiation. The tube also demonstrated a water purification capacity at a rate 2.0 times higher than a-silica tube without TiO2 impregnation. Therefore, the tubes have a great potential for developing compact and in-line VOC removal and water-purification units.

  2. Effect of the metal nature on the reaction mechanism of the partial oxidation of ethanol over CeO{sub 2}-supported Pt and Rh catalysts

    Silva, A.M.; Barandas, A.P.M.G.; Mattos, L.V.; Noronha, F.B. [Instituto Nacional de Tecnologia (INT), Av. Venezuela 82, CEP 20081-312, Rio de Janeiro (Brazil); Costa, L.O.O. [Instituto Nacional de Tecnologia (INT), Av. Venezuela 82, CEP 20081-312, Rio de Janeiro (Brazil); Instituto Militar de Engenharia, Praca General Tiburcio, 80 Praia Vermelha, Rio de Janeiro 22290-270 (Brazil); Borges, L.E.P. [Instituto Militar de Engenharia, Praca General Tiburcio, 80 Praia Vermelha, Rio de Janeiro 22290-270 (Brazil)

    2008-04-15

    In this work, the effect of the metal nature on the reaction mechanism of the partial oxidation of ethanol on Pt/CeO{sub 2} and Rh/CeO{sub 2} catalysts was studied by using diffuse reflectance infrared spectroscopy (DRIFTS) analyses. The results showed that the nature of the metal affected the reaction mechanism. On Pt/CeO{sub 2} catalyst, adsorption of ethanol gives rise to ethoxy species, which can be decomposed, producing CH{sub 4}, H{sub 2} and CO, and dehydrogenated, forming acetaldehyde. The acetaldehyde species are dehydrogenated to acetyl species or may desorb. The acetyl species can be oxidized to acetate species or can be decomposed, forming CH{sub 4}, H{sub 2} and CO. Furthermore, the acetate species previously formed can be decomposed to CH{sub 4}, CO and/or oxidized to CO{sub 2} via carbonate species. On the other hand, for Rh-based catalyst, the ethoxy species can be also dehydrogenated to a cyclic compound (oxametallacycle). This intermediate is dissociated to CO, CH{sub x} and C{sub x}, which are oxidized to CO{sub 2}. Furthermore, it was observed that the oxidation of acetyl species to acetate species and the formation of CO{sub 2} are favored depending on the presence of the O{sub 2} in the feed on Pt/CeO{sub 2} and Rh/CeO{sub 2} catalysts, respectively. (author)

  3. Dehydration and Dehydrogenation of Ethylene Glycol on Rutile TiO2(110)

    Li, Zhenjun; Kay, Bruce D.; Dohnalek, Zdenek

    2013-08-07

    The interactions of ethylene glycol (EG) with partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on the surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one EG per two Ti sites. Most of the adsorbed ethanol (~80%) undergoes further reactions to other products. Two major channels are observed, dehydration yielding ethylene and water and dehydrogenation yielding acetaldehyde and hydrogen. Hydrogen formation is rather surprising as it has not been observed previously on TiO2(110) from simple organic molecules. The coverage dependent yields of ethylene and acetaldehyde correlate well with that of water and hydrogen, respectively. Dehydration dominates at lower EG coverages (< 0.2 ML) and plateaus as the coverage is increased to saturation. Dehydrogenation is observed primarily at higher EG coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.

  4. 顶空-GC/FID测定水中乙醛丙烯腈吡啶

    张琢; 谷宇

    2015-01-01

    We successfully build a standard analytical method for the detection of acetaldehyde, acrylonitrile, and pyridine in water using gas chromatography-flame ionization detector (GC-FID).Three samples with concentration of 0.005 mg/L, 0.05 mg/L and 0.50mg/L were analyzed and showed a high recovery rate between 82%and 98%and a low relative standard deviation from 2.4%to 5.0%. These results confirm that this method has high accuracy, high precision and high reproducibility, which, consequently, is appropriate for detecting and analyzing acetaldehyde, acrylonitrile, and pyridine in water.%建立了顶空-气相色谱-氢火焰离子化检测器(GC-FID)检测水中乙醛丙烯腈吡啶的方法。根据加标浓度为0.005mg/L、0.05mg/L和0.50mg/L,回收率在82-98%之间,相对标准偏差为2.4-5.0%之间的测定结果,说明该方法准确度高、精确性高、重现性良好,符合水质测定乙醛丙烯腈吡啶的分析。

  5. Safety Evaluation of the Grape Marc Spirit by GC-FID Analysis

    Teodora Coldea

    2013-11-01

    Full Text Available There were investigated grape marc spirits regarding their safety on consumers. Major volatile compounds which present risk to human health (such as methanol, furfural, and acetaldehyde and ethyl alcohol content were compared to European Union Regulation and other values found in previous studies.  The aim of our study was to evaluate the safety of grape marc spirits considering their content in major volatile compounds by comparison with the requirements of European Union Regulation. We investigated the ethyl alcohol content by electronic densimetry and 10 major volatile compounds (acetaldehyde, ethyl acetate, methanol, 1-propanol, 1-butanol, 2-butanol, isobutyl alcohol, isoamyl alcohol, amyl active alcohol and furfural by Gas Chromatography coupled with Flame Ionization Detector. We used reference chemicals to identify these compounds and 3-pentanol as internal standard to quantify the volatiles. Results were compared with the requirements of European Union Regulation. All major volatile compounds registered values in accordance to EU Regulation and the grape pomace spirits samples do not present any kind of risk for consumption.

  6. FTIR-ATR spectroscopy applied to quality control of grape-derived spirits.

    Anjos, Ofélia; Santos, António J A; Estevinho, Letícia M; Caldeira, Ilda

    2016-08-15

    The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400cm(-1)) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r(2)=99.4; RPD=12.8), alcoholic strength (r(2)=97.2; RPD=6.0), acetaldehyde (r(2)=98.2; RPD=7.5) and fusel alcohols (r(2) from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis. PMID:27006210

  7. The γ radiolysis at room temperature of liquid deaerated isopropanol

    The main products formed in the room temperature γ radiolysis of liquid isopropanol, and their respective yields, are: hydrogen 3.8, methane 1.6, acetone 3.4, acetaldehyde 1.1, and pinacol 0.3. These results give a material balance in good agreement with the formula of isopropanol and lead to a value for the yield of decomposition: 5, 3. The absence of butanediol 2.3 shows that the acetaldehyde cannot come from the dismutation of hydroxyethyl radicals. The variations of the hydrogen yield in the neutral medium with the concentration of added electron scavengers may be explained in terms of the model proposed by Freeman and FAYADH which supposes the existence of spurs. The yield of solvated electrons diffusing into the bulk of the solution and also the ratios of rate constants for the reactions of the scavengers with the electrons may likewise be obtained on the basis of this model. Certain effects not foreseen by this model may result from the capture of electrons solvated or not, whose mode of disappearance in pure alcohol remains unknown. One may distinguish a yield of excited molecules of at least 2, of which 80 per cent lead to the production of molecular hydrogen and 20 per cent to that of molecular methane, and an ionization yield of 2. 2. The discussion of the various mechanisms which may lead to the formation of the products indicates that these yields may be higher than the values quoted. (author)

  8. Isolation and expression of NAC genes during persimmon fruit postharvest astringency removal.

    Min, Ting; Wang, Miao-Miao; Wang, Hongxun; Liu, Xiaofen; Fang, Fang; Grierson, Donald; Yin, Xue-Ren; Chen, Kun-Song

    2015-01-01

    NAC genes have been characterized in numerous plants, where they are involved in responses to biotic and abiotic stress, including low oxygen stress. High concentration of CO2 is one of the most effective treatments to remove astringency of persimmon fruit owing to the action of the accumulated anoxia metabolite acetaldehyde. In model plants, NAC genes have been identified as being responsive to low oxygen. However, the possible relationship between NAC transcription factors and persimmon astringency removal remains unexplored. In the present research, treatment with a high concentration of CO2 (95%) effectively removed astringency of "Mopan" persimmon fruit by causing decreases in soluble tannin. Acetaldehyde content increased in response to CO2 treatment concomitantly with astringency removal. Using RNA-seq and Rapid amplification of cDNA ends (RACE), six DkNAC genes were isolated and studied. Transcriptional analysis indicated DkNAC genes responded differentially to CO2 treatment; DkNAC1, DkNAC3, DkNAC5 and DkNAC6 were transiently up-regulated, DkNAC2 was abundantly expressed 3 days after treatment, while the DkNAC4 was suppressed during astringency removal. It is proposed that DkNAC1/3/5/6 could be important candidates as regulators of persimmon astringency removal and the roles of other member are also discussed. PMID:25599529

  9. Ambient levels of carbonyl compounds and their sources in Guangzhou, China

    Feng, Yanli; Wen, Sheng; Chen, Yingjun; Wang, Xinming; Lü, Huixiong; Bi, Xinhui; Sheng, Guoying; Fu, Jiamo

    Ambient levels of carbonyl compounds and their possible sources, vehicular exhaust and cooking exhaust, were studied at seven places in Guangzhou, including five districts (a residential area, an industrial area, a botanical garden, a downtown area and a semi-rural area), a bus station and a restaurant during the period of June-September 2003. Nineteen carbonyl compounds were identified in the ambient air, of which acetone was the most abundant carbonyl, followed by formaldehyde and acetaldehyde. Only little changes were found in carbonyl concentration levels in the five different districts because of their dispersion and mixture in the atmosphere in summer. The lower correlations between the carbonyls' concentrations might result from the mixture of carbonyls derived from different sources, including strong photochemical reactions at noon in summer. Formaldehyde and acetaldehyde were the main carbonyls in bus station, while straight-chain carbonyls were comparatively abundant in cooking exhaust. Besides vehicular exhaust, cooking might be another major source of carbonyl compounds in Guangzhou City, especially for high molecular weight carbonyls.

  10. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

    N. La-Salvia

    2015-06-01

    Full Text Available AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption (BET method, CO2chemisorption and Fourier transform infrared spectroscopy (FT-IR. When ethanol was completely converted on Al-MCM-41 and 16%Ba/Al-MCM-41, the reaction products showed a high selectivity for ethylene (90-98%. However, on the 1.4%Cr-16%Ba/Al-MCM-41 catalyst, a greater number of reaction products were obtained such as ethylene, acetaldehyde, diethyl ether and 1,3-butadiene. The maximum 1,3-butadiene yield obtained from ethanol reaction was 25% at 723 K and W/FEtOH = 15 g h mol-1. The latter result was obtained in a single step and without addition of reaction promoters (e.g., acetaldehyde, crotonaldehyde, hydrogen in the feed stream to the reactor.

  11. Ethanol-induced impairment of hepatic glycoprotein secretion in the isolated rat liver perfusion model

    The authors have previously shown that acute administration of ethanol inhibits hepatic glycoprotein secretion in vivo. This ethanol-induced effect appears to be mediated by its reactive metabolite, acetaldehyde. Since hormonal influences and vascular changes can not be controlled in vivo during ethanol administration, they investigated the effect of ethanol in the isolated perfused liver model. Rat liver from fed animals was perfused with oxygenated KRB at 3 ml/min/g liver for 4 hrs. Since ethanol inhibits proteins synthesis in vitro, protein acceptor pool size was equalized in both ethanol and control perfused livers with 1 mM cycloheximide. 3H-glucosamine was used to label hepatic secretory glycoproteins in the perfusate. Colchicine, a known inhibitor of protein secretion, impaired the secretion of labeled glycoproteins with a concomitant retention of these export proteins in the liver; therefore, confirming the authors secretory model. Ethanol (50 mM) inhibited the appearance of glucosamine-labeled glycoproteins by 60% into the perfusate as compared to control livers. Pretreatment of animals with cyanamide (an aldehyde dehydrogenase inhibitor) further potentiated this effect of ethanol in the isolated perfused liver. These data suggest that ethanol inhibits hepatic glycoprotein secretion in the isolated liver perfusion model, and this ethanol-induced impairment appears to be mediated by acetaldehyde

  12. Metabolism of Nω -methylserotonin, a serotonergic constituent of black cohosh (Cimicifuga racemosa, L. (Nutt.)), by human liver microsomes.

    Nikolić, Dejan; Li, Jinghu; van Breemen, Richard B

    2014-12-01

    The roots/rhizomes of black cohosh (Cimicifuga racemosa L. (Nutt.) (syn. Actaea racemosa L.) are a popular dietary supplements among women for management of menopausal symptoms. Although not estrogenic, Nω -methylserotonin has been identified in black cohosh as a potent agonist of serotonin 5-HT1A and 5-HT7 receptors. In the present study, in vitro metabolism of Nω -methylserotonin was investigated to gain insights into aspects of the bioavailability of this compound. The major metabolic pathway was determined to be conversion into 5-hydroxyindole acetaldehyde catalyzed by the monoamine oxidase A (MAO-A). 5-Hydroxyindole acetaldehyde could be further oxidized to form 5-hydroxyindole acetic acid by the action of microsomal aldehyde dehydrogenase or reduced to 5-hydroxy tryptophol by the action of aldehyde reductase. The cytochrome P450 enzymes had only a minor role in the metabolism of Nω -methylserotonin and then only when MAO-A was inhibited. In many aspects, the metabolism of Nω -methylserotonin was similar to the metabolism of serotonin, suggesting that this compound is unlikely to elicit CNS effects due to rapid metabolism by the widely distributed MAO-A. PMID:24817649

  13. The roles of aldehyde dehydrogenases (ALDHs in the PDH bypass of Arabidopsis

    Lin Ming

    2009-03-01

    Full Text Available Abstract Background Eukaryotic aldehyde dehydrogenases (ALDHs, EC 1.2.1, which oxidize aldehydes into carboxylic acids, have been classified into more than 20 families. In mammals, Family 2 ALDHs detoxify acetaldehyde. It has been hypothesized that plant Family 2 ALDHs oxidize acetaldehyde generated via ethanolic fermentation, producing acetate for acetyl-CoA biosynthesis via acetyl-CoA synthetase (ACS, similar to the yeast pathway termed the "pyruvate dehydrogenase (PDH bypass". Evidence for this pathway in plants has been obtained from pollen. Results To test for the presence of the PDH bypass in the sporophytic tissue of plants, Arabidopsis plants homozygous for mutant alleles of all three Family 2 ALDH genes were fed with 14C-ethanol along with wild type controls. Comparisons of the incorporation rates of 14C-ethanol into fatty acids in mutants and wild type controls provided direct evidence for the presence of the PDH bypass in sporophytic tissue. Among the three Family 2 ALDHs, one of the two mitochondrial ALDHs (ALDH2B4 appears to be the primary contributor to this pathway. Surprisingly, single, double and triple ALDH mutants of Arabidopsis did not exhibit detectable phenotypes, even though a Family 2 ALDH gene is required for normal anther development in maize. Conclusion The PDH bypass is active in sporophytic tissue of plants. Blocking this pathway via triple ALDH mutants does not uncover obvious visible phenotypes.

  14. Acetylene as Fast Food: Implications for Development of Life on Anoxic Primordial Earth and in the Outer Solar System

    Oremland, Ronald S.; Voytek, Mary A.

    2008-02-01

    Acetylene occurs, by photolysis of methane, in the atmospheres of jovian planets and Titan. In contrast, acetylene is only a trace component of Earth's current atmosphere. Nonetheless, a methane-rich atmosphere has been hypothesized for early Earth; this atmosphere would also have been rich in acetylene. This poses a paradox, because acetylene is a potent inhibitor of many key anaerobic microbial processes, including methanogenesis, anaerobic methane oxidation, nitrogen fixation, and hydrogen oxidation. Fermentation of acetylene was discovered 25 years ago, and Pelobacter acetylenicus was shown to grow on acetylene by virtue of acetylene hydratase, which results in the formation of acetaldehyde. Acetaldehyde subsequently dismutates to ethanol and acetate (plus some hydrogen). However, acetylene hydratase is specific for acetylene and does not react with any analogous compounds. We hypothesize that microbes with acetylene hydratase played a key role in the evolution of Earth's early biosphere by exploiting an available source of carbon from the atmosphere and in so doing formed protective niches that allowed for other microbial processes to flourish. Furthermore, the presence of acetylene in the atmosphere of a planet or planetoid could possibly represent evidence for an extraterrestrial anaerobic ecosystem.

  15. The fermentation stress response protein Aaf1p/Yml081Wp regulates acetate production in Saccharomyces cerevisiae.

    Christopher J Walkey

    Full Text Available The production of acetic acid during wine fermentation is a critical issue for wineries since the sensory quality of a wine can be affected by the amount of acetic acid it contains. We found that the C2H2-type zinc-finger transcription factor YML081Wp regulated the mRNA levels of ALD4 and ALD6, which encode a cytosolic acetaldehyde dehydrogenase (ACDH and a mitochondrial ACDH, respectively. These enzymes produce acetate from acetaldehyde as part of the pyruvate dehydrogenase bypass. This regulation was also reflected in the protein levels of Ald4p and Ald6p, as well as total ACDH activity. In the absence of ALD6, YML081W had no effect on acetic acid levels, suggesting that this transcription factor's effects are mediated primarily through this gene. lacZ reporter assays revealed that Yml081wp stimulates ALD6 transcription, in large part from a GAGGGG element 590 base pairs upstream of the translation start site. The non-annotated ORF YML081W therefore encodes a transcription factor that regulates acetate production in Saccharomyces cerevisiae. We propose AAF1 as a gene name for the YML081W ORF.

  16. Oxidation of 2-propanol ligands during collision-induced dissociation of a gas-phase uranyl complex

    van Stipdonk, Michael J.; Chien, Winnie; Anbalagan, Victor; Gresham, Garold L.; Groenewold, Gary S.

    2004-10-01

    We demonstrate, by way of multi-stage tandem mass spectrometry and extensive deuterium labeling, that 2-propanol is converted to acetone, and 2-propoxide to acetaldehyde, when monopositive 2-propanol-coordinated uranyl-ligand cations are subjected to collision-induced dissociation in the gas-phase environment of an ion trap mass spectrometer. A species with formula [(UO2OCH(CH3)2)(HOCH(CH3)2)]+, derived from dissociation of the gas-phase precursor [(UO2NO3)(HOCH(CH3)2)3]+ eliminates two H atoms and CH3 in consecutive stages to generate a monopositive complex composed of the U(V) species UO2+ coordinated by acetone and acetaldehyde, i.e. [UO2+(OC(CH3)2)(OC(H)CH3)]. Dissociation of this latter ion resulted in elimination of the two coordinating carbonyl ligands in two consecutive dissociation stages to leave UO2+. Analogous reactions were not observed for uranyl complexes containing 1-propanol or 2-methyl-2-propanol, or for cationic complexes with divalent metals such as Ni2+, Co2+, Pb2+ and Ca2+. One explanation for these reactions is bond insertion by the metal center in the bis-ligated uranyl complex, which would be expected to have an LUMO consisting of unoccupied 6d-orbitals that would confer transition metal-like behavior on the complex.

  17. Bioethanol/gasoline blends for fuelling conventional and hybrid scooter. Regulated and unregulated exhaust emissions

    Costagliola, Maria Antonietta; Prati, Maria Vittoria; Murena, Fabio

    2016-05-01

    The aim of this experimental activity was to evaluate the influence of ethanol fuel on the pollutant emissions measured at the exhaust of a conventional and a hybrid scooter. Both scooters are 4-stroke, 125 cm3 of engine capacity and Euro 3 compliant. They were tested on chassis dynamometer for measuring gaseous emissions of CO, HC, NOx, CO2 and some toxic micro organic pollutants, such as benzene, 1,3-butadiene, formaldehyde and acetaldehyde. The fuel consumption was estimated throughout a carbon balance on the exhaust species. Moreover, total particles number with diameter between 20 nm up to 1 μm was measured. Worldwide and European test cycles were carried out with both scooters fuelled with gasoline and ethanol/gasoline blends (10/90, 20/80 and 30/70% vol). According to the experimental results relative to both scooter technologies, the addiction of ethanol in gasoline reduces CO and particles number emissions. The combustion of conventional scooter becomes unstable when a percentage of 30%v of bioethanol is fed; as consequence a strong increasing of hydrocarbon is monitored, including carcinogenic species. The negative effects of ethanol fuel are related to the increasing of fuel consumption due to the less carbon content for volume unit and to the increasing of formaldehyde and acetaldehyde due to the higher oxygen availability. Almost 70% of Ozone Formation Potential is covered by alkenes and aromatics.

  18. Unregulated emissions from light-duty hybrid electric vehicles

    Suarez-Bertoa, R.; Astorga, C.

    2016-07-01

    The number of registrations of light duty hybrid electric vehicles has systematically increased over the last years and it is expected to keep growing. Hence, evaluation of their emissions becomes very important in order to be able to anticipate their impact and share in the total emissions from the transport sector. For that reason the emissions from a Euro 5 compliant hybrid electric vehicle (HV2) and a Euro 5 plug-in hybrid electric vehicle (PHV1) were investigated with special interest on exhaust emissions of ammonia, acetaldehyde and ethanol. Vehicles were tested over the World harmonized Light-duty Test Cycle (WLTC) at 23 and -7 °C using two different commercial fuels E5 and E10 (gasoline containing 5% and 10% vol/vol of ethanol, respectively). PHV1 resulted in lower emissions than HV2 due to the pure electric strategy used by the former. PHV1 and HV2 showed lower regulated emissions than conventional Euro 5 gasoline light duty vehicles. However, emissions of ammonia (2-8 and 6-15 mg km-1 at 22 and -7 °C, respectively), ethanol (0.3-0.8 and 2.6-7.2 mg km-1 at 22 and -7 °C, respectively) and acetaldehyde (∼0.2 and 0.8-2.7 mg km-1 at 22 and -7 °C, respectively) were in the same range of those recently reported for conventional gasoline light duty vehicles.

  19. Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

    Kajos, M. K.; Rantala, P.; Hill, M.; Hellén, H.; Aalto, J.; Patokoski, J.; Taipale, R.; Hoerger, C. C.; Reimann, S.; Ruuskanen, T. M.; Rinne, J.; Petäjä, T.

    2015-10-01

    Proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography mass spectrometry GC-MS) are commonly used methods for automated in situ measurements of various volatile organic compounds (VOCs) in the atmosphere. In order to investigate the reliability of such measurements, we operated four automated analyzers using their normal field measurement protocol side by side at a boreal forest site. We measured methanol, acetaldehyde, acetone, benzene and toluene by two PTR-MS and two GC-MS instruments. The measurements were conducted in southern Finland between 13 April and 14 May 2012. This paper presents correlations and biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds), while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively). For some compounds, notably for methanol, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90). The systematic difference manifests as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50-100 % in the methanol emissions measured by commonly used methods.

  20. Acetylene as fast food: Implications for development of life on anoxic primordial earth and in the outer solar system

    Oremland, R.S.; Voytek, M.A.

    2008-01-01

    Acetylene occurs, by photolysis of methane, in the atmospheres of jovian planets and Titan. In contrast, acetylene is only a trace component of Earth's current atmosphere. Nonetheless, a methane-rich atmosphere has been hypothesized for early Earth; this atmosphere would also have been rich in acetylene. This poses a paradox, because acetylene is a potent inhibitor of many key anaerobic microbial processes, including methanogenesis, anaerobic methane oxidation, nitrogen fixation, and hydrogen oxidation. Fermentation of acetylene was discovered 25 years ago, and Pelobacter acetylenicus was shown to grow on acetylene by virtue of acetylene hydratase, which results in the formation of acetaldehyde. Acetaldehyde subsequently dismutates to ethanol and acetate (plus some hydrogen). However, acetylene hydratase is specific for acetylene and does not react with any analogous compounds. We hypothesize that microbes with acetylene hydratase played a key role in the evolution of Earth's early biosphere by exploiting an available source of carbon from the atmosphere and in so doing formed protective niches that allowed for other microbial processes to flourish. Furthermore, the presence of acetylene in the atmosphere of a planet or planetoid could possibly represent evidence for an extraterrestrial anaerobic ecosystem. ?? Mary Ann Liebert, Inc.

  1. Photoinduced catalytic synthesis of biologically important metabolites from formaldehyde and ammonia under plausible "prebiotic" conditions

    Delidovich, I. V.; Taran, O. P.; Simonov, A. N.; Matvienko, L. G.; Parmon, V. N.

    2011-08-01

    The article analyzes new and previously reported data on several catalytic and photochemical processes yielding biologically important molecules. UV-irradiation of formaldehyde aqueous solution yields acetaldehyde, glyoxal, glycolaldehyde and glyceraldehyde, which can serve as precursors of more complex biochemically relevant compounds. Photolysis of aqueous solution of acetaldehyde and ammonium nitrate results in formation of alanine and pyruvic acid. Dehydration of glyceraldehyde catalyzed by zeolite HZSM-5-17 yields pyruvaldehyde. Monosaccharides are formed in the course of the phosphate-catalyzed aldol condensation reactions of glycolaldehyde, glyceraldehyde and formaldehyde. The possibility of the direct synthesis of tetroses, keto- and aldo-pentoses from pure formaldehyde due to the combination of the photochemical production of glycolahyde and phosphate-catalyzed carbohydrate chain growth is demonstrated. Erythrulose and 3-pentulose are the main products of such combined synthesis with selectivity up to 10%. Biologically relevant aldotetroses, aldo- and ketopentoses are more resistant to the photochemical destruction owing to the stabilization in hemiacetal cyclic forms. They are formed as products of isomerization of erythrulose and 3-pentulose. The conjugation of the concerned reactions results in a plausible route to the formation of sugars, amino and organic acids from formaldehyde and ammonia under presumed 'prebiotic' conditions.

  2. Evaluation of photocatalytic activities and characteristics of Cu- or Fe-modified nitrogen-doped titanium dioxides for applications in environmental purification

    Ohwaki, Takeshi; Saeki, Shu; Aoki, Koyu; Morikawa, Takeshi

    2016-01-01

    Photocatalytic activities, as manifested in gas decomposition rates of volatile organic compounds under visible light irradiation, are well known to be enhanced by Cu or Fe compounds loaded onto the surface of nitrogen-doped titanium dioxide (N-TiO2). Antimicrobial properties are also known to be improved by Cu compounds loaded onto N-TiO2. In this study, the acetaldehyde gas decomposition rates and antimicrobial properties achieved by loading Cu or Fe compounds onto N-TiO2 have been investigated from a practical viewpoint. Enhancements of the photocatalytic activities have been confirmed, and the durability of the Cu- or Fe-modified N-TiO2 in acetaldehyde gas decomposition has been demonstrated. The enhancements have been rationalized by considering the valence states of the loaded material. The enhancements were inferred to be a result of increased amounts of oxidative species arising from the photo-Fenton reaction at the surface of the loaded metal compounds. With a view to expanding the range of indoor applications of such visible-light-sensitive photocatalysts, preparation processes, i.e., nanosizing of the powder and improvement of the immobilization on various substrates, are also discussed.

  3. Carbonyl species characteristics during the evaporation of essential oils

    Chiang, Hsiu-Mei; Chiu, Hua-Hsien; Lai, Yen-Ming; Chen, Ching-Yen; Chiang, Hung-Lung

    2010-06-01

    Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, especially under poor ventilation conditions. Lavender, lemon, rose, rosemary, and tea tree oils were selected as typical and popular essential oils to investigate in terms of composition, thermal characteristics and fifteen carbonyl constituents. Based on thermogravimetric (TG) analysis, the activation energy was 7.6-8.3 kcal mol -1, the reaction order was in the range of 0.6-0.7 and the frequency factor was 360-2838 min -1. Formaldehyde, acetaldehyde, acetone, and propionaldehyde were the dominant carbonyl compounds, and their concentrations were 0.034-0.170 ppm. The emission factors of carbonyl compounds were 2.10-3.70 mg g -1, and acetone, propionaldehyde, acetaldehyde, and formaldehyde accounted for a high portion of the emission factor of carbonyl compounds in essential oil exhaust. Some unhealthy carbonyl species such as formaldehyde and valeraldehyde, were measured at low-temperature during the vaporization of essential oils, indicating a potential effect on indoor air quality and human health.

  4. Fermented probiotic beverages based on acid whey

    Katarzyna Skryplonek

    2015-12-01

    Full Text Available Background. Production of fermented probiotic beverages can be a good method for acid whey usage. The obtained products combine a high nutritional value of whey with health benefits claimed for probiotic bac- teria. The aim of the study was to define quality properties of beverages based on fresh acid whey and milk with addition of buttermilk powder or sweet whey powder. Material and methods. Samples were inoculated with two strains of commercial probiotic cultures: Lac- tobacillus acidophilus La-5 or Bifidobacterium animalis Bb-12. After fermentation, samples were stored at refrigerated conditions. After 1, 4, 7, 14 and 21 days sensory characteristics, hardness, acetaldehyde content, titratable acidity, pH acidity and count of bacteria cells were evaluated. Results. Throughout all storage period, the number of bacteria was higher than 8 log cfu/ml in the all sam- ples. Beverages with La-5 strain had higher hardness and acidity, whilst samples with Bb-12 contained more acetaldehyde. Samples with buttermilk powder had better sensory properties than with sweet whey powder. Conclusions. Obtained products made of acid whey combined with milk and fortified with buttermilk pow- der or sweet whey powder, are good medium for growth and survival of examined probiotic bacteria strains. The level of bacteria was sufficient to provide health benefits to consumers.

  5. Oxidation of rapeseed oil in waste activated bleaching earth and its effect on riboflavin production in culture of Ashbya gossypii.

    Park, Enoch Y; Ming, Hwa

    2004-01-01

    Long-term behavior of rapeseed oil in waste activated bleaching earth (ABE) and the effect of this oil on riboflavin production in the culture of Ashbya gossypii were investigated. Waste ABE with 40% (w/w) rapeseed oil was stored for 80 d, and the extent of oxidation of rapeseed oil was measured by several analytical methods to determine the chemical properties of the oil at different stages of the oil deterioration process:peroxide value, acid value, concentrations of organic acids, acetaldehyde and unsaturated fatty acid, and content of polymerized triglycerides. Peroxide value, acid value, and concentrations of organic acids and acetaldehyde did not affect riboflavin production. However, the content of polymerized triglycerides markedly increased the viscosity of rapeseed oil and was the main reason for the exponential decrease in riboflavin production. A good correlation between the polymerized triglyceride content or viscosity and riboflavin production in the culture of A. gossypii using rapeseed oil as the sole carbon source was found. PMID:16233590

  6. Synthesis and modification of nano-sized TiO2 for photo-degradation process under visible light irradiation; a Placket–Burman experimental design

    Graphical abstract: - Highlights: • Nanosized TiO2 doped with nitrogen and iron was produced by sol-gel method. • Linear models were derived to relate the phase and particle size to synthesis factors. • High photocatalytic activity was observed for acetaldehyde degradation. - Abstract: In this research, nitrogen and iron (III) co-doped nano TiO2 (N-Fe-TiO2) was prepared by sol-gel method using ammonium chloride and iron chloride solutions as nitrogen and iron sources, respectively. The effect of synthesis parameters (weight ratios of N/TiO2 and Fe/TiO2, synthesis temperature, calcination time and temperature) was simultaneously investigated on the quality of the N-Fe-TiO2 product by a two-level Placket–Burman experimental design. The synthesized powders were characterized by XRD, XPS and UV–Vis spectroscopy techniques. The mean crystal size and anatase content were determined and evaluated as the linear functions of so-called synthesis parameters by the statistical analysis and regression. The 2%N-1%Fe-TiO2 product by 11 nm mean crystal size and 78% anatase content, synthesized at 35 °C and calcined at 500 °C during 2 h, exhibited the most significant activity during the photo-degradation of acetaldehyde under visible light irradiation and its efficiency was obtained about four times more than photocatalytic activity of Degussa TiO2-P25

  7. Emission of oxygenated volatile organic compounds (OVOCs) during the aerobic decomposition of orange wastes.

    Wu, Ting; Wang, Xinming

    2015-07-01

    Oxygenated volatile organic compounds (OVOCs) emitted from orange wastes during aerobic decomposition were investigated in a laboratory-controlled incubator for a period of two months. Emission of total OVOCs (TOVOCs) from orange wastes reached 1714 mg/dry kg (330 mg/wet kg). Ethanol, methanol, ethyl acetate, methyl acetate, 2-butanone and acetaldehyde were the most abundant OVOC species with shares of 26.9%, 24.8%, 20.3%, 13.9%, 2.8% and 2.5%, respectively, in the TOVOCs released. The emission fluxes of the above top five OVOCs were quite trivial in the beginning but increased sharply to form one "peak emission window" with maximums at days 1-8 until leveling off after 10 days. This type of "peak emission window" was synchronized with the CO2 fluxes and incubation temperature of the orange wastes, indicating that released OVOCs were mainly derived from secondary metabolites of orange substrates through biotic processes rather than abiotic processes or primary volatilization of the inherent pool in oranges. Acetaldehyde instead had emission fluxes decreasing sharply from its initial maximum to nearly zero in about four days, suggesting that it was inherent rather than secondarily formed. For TOVOCs or all OVOC species except 2-butanone and acetone, over 80% of their emissions occurred during the first week, implying that organic wastes might give off a considerable amount of OVOCs during the early disposal period under aerobic conditions. PMID:26141879

  8. Potential effects of using biodiesel in road-traffic on air quality over the Porto urban area, Portugal

    Ribeiro, Isabel; Monteiro, Alexandra; Lopes, Myriam

    2016-01-01

    This work aims to assess the impacts of biodiesel blends use in road-traffic on air quality. In this frame, the air quality numerical modelling system WRF-EURAD was applied over Portugal and the Porto urban area, forced by two emission scenarios (including CO, NOx, PM10, PM2.5, NMVOC, formaldehyde, acetaldehyde, acrolein and benzene): a reference scenario, without biofuels, and a scenario where a B20 fuel (20% biodiesel/80% diesel, v/v) is used by the diesel vehicle fleet. Regarding carbonyl compounds, emission scenarios pointed out that B20 fuel can promote an increase of 20% on formaldehyde, acetaldehyde and acrolein emissions, leading to increments on equivalent ozone production. On the other hand, through the air quality modelling exercise, it was verified that the use of B20 helps in controlling air pollution, improving CO and NO2 concentrations in urban airshed in about 20% and 10%, respectively, taking into account a regional simulation grid. However, according to the urban scale simulation, NO2 levels can increase in about 1%, due to the use of B20, over the Porto urban area. For the remaining studied pollutants, namely PM10 and PM2.5, mean concentrations will be reduced all over the territory, however in a negligible amount of <1%.

  9. Synthesis of C4 and C8 Chemicals from Ethanol on MgO-Incorporated Faujasite Catalysts with Balanced Confinement Effects and Basicity.

    Zhang, Lu; Pham, Tu N; Faria, Jimmy; Santhanaraj, Daniel; Sooknoi, Tawan; Tan, Qiaohua; Zhao, Zheng; Resasco, Daniel E

    2016-04-01

    A new type of catalyst has been designed to adjust the basicity and level of molecular confinement of KNaX faujasites by controlled incorporation of Mg through ion exchange and precipitation of extraframework MgO clusters at varying loadings. The catalytic performance of these catalysts was compared in the conversion of C2 and C4 aldehydes to value-added products. The product distribution depends on both the level of acetaldehyde conversion and the fraction of magnesium as extraframework species. These species form rather uniform and highly dispersed nanostructures that resemble nanopetals. Specifically, the sample containing Mg only in the form of exchangeable Mg(2+) ions has much lower activity than those in which a significant fraction of Mg exists as extraframework MgO. Both the (C6 +C8 )/C4 and C8 /C6 ratios increase with additional extraframework Mg at high acetaldehyde conversion levels. These differences in product distribution can be attributed to 1) higher basicity density on the samples with extraframework species, and 2) enhanced confinement inside the zeolite cages in the presence of these species. Additionally, the formation of linear or aromatic C8 aldehyde compounds depends on the position on the crotonaldehyde molecule from which abstraction of a proton occurs. In addition, catalysts with different confinement effects result in different C8 products. PMID:26938793

  10. The Products of the Thermal Decomposition of CH3CHO

    Vasiliou, AnGayle; Piech, Krzysztof M.; Zhang, Xu; Nimlos, Mark R.; Ahmed, Musahid; Golan, Amir; Kostko, Oleg; Osborn, David L.; Daily, John W.; Stanton, John F.; Ellison, G. Barney

    2011-04-06

    We have used a heated 2 cm x 1 mm SiC microtubular (mu tubular) reactor to decompose acetaldehyde: CH3CHO + DELTA --> products. Thermal decomposition is followed at pressures of 75 - 150 Torr and at temperatures up to 1700 K, conditions that correspond to residence times of roughly 50 - 100 mu sec in the mu tubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: VUV photoionization mass spectroscopy (PIMS) and infrared (IR) absorption spectroscopy after isolation in a cryogenic matrix. Besides CH3CHO, we have studied three isotopologues, CH3CDO, CD3CHO, and CD3CDO. We have identified the thermal decomposition products CH3(PIMS), CO (IR, PIMS), H (PIMS), H2 (PIMS), CH2CO (IR, PIMS), CH2=CHOH (IR, PIMS), H2O (IR, PIMS), and HC=CH (IR, PIMS). Plausible evidence has been found to support the idea that there are at least three different thermal decomposition pathways for CH3CHO: Radical decomposition: CH3CHO + DELTA --> CH3 + [HCO] --> CH3 + H + CO Elimination: CH3CHO + DELTA --> H2 + CH2=C=O. Isomerization/elimination: CH3CHO + DELTA --> [CH2=CH-OH] --> HC=CH + H2O. Both PIMS and IR spectroscopy show compelling evidence for the participation of vinylidene, CH2=C:, as an intermediate in the decomposition of vinyl alchohol: CH2=CH-OH + DELTA --> [CH2=C:] + H2O --> HC=CH + H2O.

  11. Does acute exposure to aldehydes impair pulmonary function and structure?

    Abreu, Mariana de; Neto, Alcendino Cândido; Carvalho, Giovanna; Casquillo, Natalia Vasconcelos; Carvalho, Niedja; Okuro, Renata; Ribeiro, Gabriel C Motta; Machado, Mariana; Cardozo, Aléxia; Silva, Aline Santos E; Barboza, Thiago; Vasconcellos, Luiz Ricardo; Rodrigues, Danielle Araujo; Camilo, Luciana; Carneiro, Leticia de A M; Jandre, Frederico; Pino, Alexandre V; Giannella-Neto, Antonio; Zin, Walter A; Corrêa, Leonardo Holanda Travassos; Souza, Marcio Nogueira de; Carvalho, Alysson R

    2016-07-15

    Mixtures of anhydrous ethyl alcohol and gasoline substituted for pure gasoline as a fuel in many Brazilian vehicles. Consequently, the concentrations of volatile organic compounds (VOCs) such as ketones, other organic compounds, and particularly aldehydes increased in many Brazilian cities. The current study aims to investigate whether formaldehyde, acetaldehyde, or mixtures of both impair lung function, morphology, inflammatory and redox responses at environmentally relevant concentrations. For such purpose, C57BL/6 mice were exposed to either medical compressed air or to 4 different mixtures of formaldehyde and acetaldehyde. Eight hours later animals were anesthetized, paralyzed and lung mechanics and morphology, inflammatory cells and IL-1β, KC, TNF-α, IL-6, CCL2, MCP-1 contents, superoxide dismutase and catalalase activities were determined. The extra pulmonary respiratory tract was also analyzed. No differences could be detected between any exposed and control groups. In conclusion, no morpho-functional alterations were detected in exposed mice in relation to the control group. PMID:27102012

  12. Reduction of NOx in synthetic diesel exhaust via two-step plasma-catalysis treatment

    Significant reduction of NOx in synthetic light duty diesel exhaust has been achieved over a broad temperature window by combining atmospheric plasma with appropriate catalysts. The technique relies on the addition of hydrocarbon reductant prior to passing the simulated exhaust through a non-thermal plasma and a catalyst bed. The observed chemistry in the plasma includes conversion of NO to NO2 as well as the partial oxidation of the hydrocarbon. The overall NOx reduction has a maximum of less than 80%, with this maximum obtained only at high-energy input into the plasma, high concentration of hydrocarbon reductant and low space velocity. We present data in this paper illustrating that a multiple-step treatment strategy, whereby two or more plasma-catalyst reactors are utilized in series, can increase the maximum NOx conversion obtainable. Alternatively, this technique can reduce the energy and/or hydrocarbon requirements for a fixed conversion efficiency. When propene is used as the reductant, the limiting reagent for the overall process is most likely acetaldehyde. The data suggest that acetaldehyde is formed in concert with NO oxidation to NO2 in the plasma stage. The limited NOx reduction efficiency attained in a single step, even with excess energy, oxygen content and/or hydrocarbon-to-NOx ratio is well explained by this hypothesis, as is the effectiveness of the multiple-step treatment strategy. We present the data here illustrating the advantage of this approach under a wide variety of conditions

  13. Relationships between functional genes in Lactobacillus delbrueckii ssp. bulgaricus isolates and phenotypic characteristics associated with fermentation time and flavor production in yogurt elucidated using multilocus sequence typing.

    Liu, Wenjun; Yu, Jie; Sun, Zhihong; Song, Yuqin; Wang, Xueni; Wang, Hongmei; Wuren, Tuoya; Zha, Musu; Menghe, Bilige; Heping, Zhang

    2016-01-01

    Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is well known for its worldwide application in yogurt production. Flavor production and acid producing are considered as the most important characteristics for starter culture screening. To our knowledge this is the first study applying functional gene sequence multilocus sequence typing technology to predict the fermentation and flavor-producing characteristics of yogurt-producing bacteria. In the present study, phenotypic characteristics of 35 L. bulgaricus strains were quantified during the fermentation of milk to yogurt and during its subsequent storage; these included fermentation time, acidification rate, pH, titratable acidity, and flavor characteristics (acetaldehyde concentration). Furthermore, multilocus sequence typing analysis of 7 functional genes associated with fermentation time, acid production, and flavor formation was done to elucidate the phylogeny and genetic evolution of the same L. bulgaricus isolates. The results showed that strains significantly differed in fermentation time, acidification rate, and acetaldehyde production. Combining functional gene sequence analysis with phenotypic characteristics demonstrated that groups of strains established using genotype data were consistent with groups identified based on their phenotypic traits. This study has established an efficient and rapid molecular genotyping method to identify strains with good fermentation traits; this has the potential to replace time-consuming conventional methods based on direct measurement of phenotypic traits. PMID:26547656

  14. Maryland air toxics regulation applicable to a natural gas compressor station

    Columbia Gas Transmission Corporation submitted an air permit application to the Maryland Department of the Environment to construct a natural gas compressor station near Rutledge, Maryland. The station consists of three natural gas-fueled internal combustion reciprocating engines, each rated at 3200 horsepower. Maximum potential pollutant emissions associated with the station operation did not trigger Prevention of Significant Deterioration review or nonattainment area New Source review. However, a minor source air permit cannot be issued without addressing Maryland's toxic air regulations. Columbia initiated a detailed investigation of toxic air pollutants, including a stack test of an identical engine. Based on this information, the proposed station was subject to the toxic air regulation for acetaldehyde, acrolein, benzene, crotonaldehyde, and formaldehyde. Compliance with the toxic air regulation for crotonaldehyde was demonstrated by having an emission rate less than the threshold emission rate, specified in the regulation. The ambient air quality impact of the other four pollutants was determined using the Industrial Source Complex dispersion model and resulted in predicted concentrations below the pollutant-specific acceptable ambient level. A carcinogenic impact analysis was performed for acetaldehyde, benzene, and formaldehyde to demonstrate compliance with the accepted risk of one in one hundred thousand

  15. Emissions of air pollutants from indoor charcoal barbecue.

    Huang, Hsiao-Lin; Lee, Whei-May Grace; Wu, Feng-Shu

    2016-01-25

    Ten types of commercial charcoal commonly used in Taiwan were investigated to study the potential health effects of air pollutants generated during charcoal combustion in barbecue restaurants. The charcoal samples were combusted in a tubular high-temperature furnace to simulate the high-temperature charcoal combustion in barbecue restaurants. The results indicated that traditional charcoal has higher heating value than green synthetic charcoal. The amount of PM10 and PM2.5 emitted during the smoldering stage increased when the burning temperature was raised. The EF for CO and CO2 fell within the range of 68-300 and 644-1225 g/kg, respectively. Among the charcoals, the lowest EF for PM2.5 and PM10 were found in Binchōtan (B1). Sawdust briquette charcoal (I1S) emitted the smallest amount of carbonyl compounds. Charcoal briquettes (C2S) emitted the largest amount of air pollutants during burning, with the EF for HC, PM2.5, PM10, formaldehyde, and acetaldehyde being the highest among the charcoals studied. The emission of PM2.5, PM10, formaldehyde, and acetaldehyde were 5-10 times those of the second highest charcoal. The results suggest that the adverse effects of the large amounts of air pollutants generated during indoor charcoal combustion on health and indoor air quality must not be ignored. PMID:26476306

  16. Photocatalytic Ethanol Oxidative Dehydrogenation over Pt/TiO2: Effect of the Addition of Blue Phosphors

    J. J. Murcia

    2012-01-01

    Full Text Available Ethanol oxidative dehydrogenation over Pt/TiO2 photocatalyst, in the presence and absence of blue phosphors, was performed. The catalyst was prepared by photodeposition of Pt on sulphated TiO2. This material was tested in a gas-solid photocatalytic fluidized bed reactor at high illumination efficiency. The effect of the addition of blue phosphors into the fluidized bed has been evaluated. The synthesized catalysts were extensively characterized by different techniques. Pt/TiO2 with a loading of 0.5 wt% of Pt appeared to be an active photocatalyst in the selective partial oxidation of ethanol to acetaldehyde improving its activity and selectivity compared to pure TiO2. In the same way, a notable enhancement of ethanol conversion in the presence of the blue phosphors has been obtained. The blue phosphors produced an increase in the level of ethanol conversion over the Pt/TiO2 catalyst, keeping at the same time the high selectivity to acetaldehyde.

  17. Homogeneous catalytic hydrogenation of bio-oil and related model aldehydes with RuCl{sub 2}(PPh{sub 3}){sub 3}

    Huang, F.; Li, W.; Lu, Q.; Zhu, X. [Anhui Province Key Laboratory of Biomass Clean Energy, University of Science and Technology of China, Hefei (China)

    2010-12-15

    A homogeneous RuCl{sub 2}(PPh{sub 3}){sub 3} catalyst was prepared for the hydrogenation of bio-oil to improve its stability and fuel quality. Experiments were first performed on three model aldehydes of acetaldehyde, furfural and vanillin selected to represent the linear aldehydes, oxygen heterocyclic aldehydes and aromatic aldehydes in bio-oil. The results demonstrated the high hydrogenation capability of this homogeneous catalyst under mild conditions (55-90 C, 1.3-3.3 MPa). The highest conversion of the three model aldehydes was over 90 %. Furfural and acetaldehyde were singly converted to furfuryl alcohol and ethanol after hydrogenation, while vanillin was mainly converted to vanillin alcohol, together with a small amount of 2-methoxy-4-methylphenol and 2-methoxyphenol. Further experiments were conducted on a bio-oil fraction extracted by ethyl acetate and on the whole bio-oil at 70 C and 3.3 MPa. Most of the aldehydes were transformed to the corresponding alcohols, and some ketones and compounds with C-C double bond were converted to more stable compounds. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Analysis of the Volatile Constituents of Irradiated Apple Juice

    The organoleptic studies and wholesomeness tests that are being carried out as part of the International Programme on the Irradiation of Fruit and Fruit Juices (Seibersdorf Project) entail analysis of the aromatic substances present in irradiated and non-irradiated juice. The volatile substances present in irradiated fruit juices were analysed by gas chromatography, with direct injection of the emitted vapours at ambient temperature and at 60°C (Weurman's Head Space Technique). The volatile constituents were identified by comparing the amounts retained in the column with those for pure substances and by removing certain constituents from the vapour with the help of chemical reagents. To simplify the analyses, the first tests were carried out on concentrated apple juice from which the volatile substances had been removed before irradiation. Irradiation gave rise to five aldehydes in the normal apple juice (acetaldehyde, isobutyraldehyde, butyraldehyde, isovaldehyde and capronaldehyde), but only three in the concentrated juice (acetaldehyde, isobutyraldehyde and isovaleraldehyde). In addition, 2-butanone appeared in the concentrated juice; however, the peak corresponding to it on the chromatogram was completely masked by the ethanol peak in the case of non-concentrated juice. Furan was also detected, together with traces of two compounds that have not yet been identified. Similar results have been obtained by pasteurization, such as in bottling by heat. (author)

  19. Isolation and Expression of NAC Genes during Persimmon Fruit Postharvest Astringency Removal

    Ting Min

    2015-01-01

    Full Text Available NAC genes have been characterized in numerous plants, where they are involved in responses to biotic and abiotic stress, including low oxygen stress. High concentration of CO2 is one of the most effective treatments to remove astringency of persimmon fruit owing to the action of the accumulated anoxia metabolite acetaldehyde. In model plants, NAC genes have been identified as being responsive to low oxygen. However, the possible relationship between NAC transcription factors and persimmon astringency removal remains unexplored. In the present research, treatment with a high concentration of CO2 (95% effectively removed astringency of “Mopan” persimmon fruit by causing decreases in soluble tannin. Acetaldehyde content increased in response to CO2 treatment concomitantly with astringency removal. Using RNA-seq and Rapid amplification of cDNA ends (RACE, six DkNAC genes were isolated and studied. Transcriptional analysis indicated DkNAC genes responded differentially to CO2 treatment; DkNAC1, DkNAC3, DkNAC5 and DkNAC6 were transiently up-regulated, DkNAC2 was abundantly expressed 3 days after treatment, while the DkNAC4 was suppressed during astringency removal. It is proposed that DkNAC1/3/5/6 could be important candidates as regulators of persimmon astringency removal and the roles of other member are also discussed.

  20. Ag@graphene oxide nanocomposite as an efficient visible-light plasmonic photocatalyst for the degradation of organic pollutants: A facile green synthetic approach

    Haldorai, Yuvaraj [Supercritical Fluids and Nano Processes Laboratory, School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of); Kim, Byung-Keuk; Jo, Youl-Lae [Department of Applied Microbiology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of); Shim, Jae-Jin, E-mail: jjshim@yu.ac.kr [Supercritical Fluids and Nano Processes Laboratory, School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of)

    2014-02-14

    We report a simple and effective supercritical route to decorate silver nanoparticles (Ag NPs) on graphene oxide (GO) using a commonly available and non-toxic glucose as a reducing agent. Transmission electron microscopy and energy-dispersive X-ray analysis confirmed that Ag NPs of size around 8–20 nm were coated on the GO surface under optimized experimental condition. Ag NPs on the GO surface were predominantly spherical in shape and well dispersed. The experimental results proved that the as-synthesized GO/Ag nanocomposite could be used as a highly efficient photocatalyst for the degradation of Rhodamine 123 dye and acetaldehyde under visible-light irradiation. The degradation results indicated that the photocatalytic performance of nanocomposite was greatly enhanced owing to the improved adsorption performance and separation efficiency of photo-generated carriers. The nanocomposite maintains a high level activity even after four times of recycle. Furthermore, the nanocomposite exhibited excellent antibacterial activity against gram-positive and gram-negative microorganisms. - Highlights: • Visible-light driven reusable photocatalyst. • Efficient degradation of Rhodamine 123 dye and acetaldehyde. • Excellent antibacterial activity. • Green synthetic approach using supercritical fluid. • New field of sustainable nanotechnology.

  1. Genetic toxicity studies of organic chemicals found as contaminants in spacecraft cabin atmospheres

    Torres, Joseph, Jr.

    1987-01-01

    Astronauts can be exposed during spaceflight to organic chemical contaminants in the spacecraft cabin atmosphere. Toxic exposures may cause lesions in the cellular DNA which are subsequently expressed as sister-chromatid exchanges (SCE). Analysis of SCE is a sensitive short term assay techinque to detect and quantitate exposures to DNA damaging (mutagenic) substances. The increase in SCE incidence over baseline (control) levels is generally proportional to the concentration of the mutagen and to the duration of exposure. The BHK-21 baby hamster kidney cell line was the in vitro test system used. Test organics were added to the culture media for 18 hrs, in concentrations ranging from one to 20 ppm. Acetaldehyde and carbon disulfide were chosen for this study since they have occurred as atmospheric contaminants in many of the STS flights, and have been reported to have toxic and mutagenic effects in various test systems. Glutaraldehyde was chosen because few data are available on the mutagenicity of this common fixative, which is carried on STS flights for use in biological experiments. Acetaldehyde was a very strong inducer of SCE at concentrations of 2 ppm and above. Glutaraldehyde and carbon disulfide failed to induce SCE.

  2. Investigation of the Bacillus cereus phosphonoacetaldehyde hydrolase catalytic mechanism

    The enzyme phosphonoacetaldehyde hydrolase (phosphonatase) from Bacillus cereus catalyzes the conversion of phosphonoacetaldehyde and phosphate. We have demonstrated that phosphonatase is inactivated when incubated with either acetaldehyde or phosphonoacetaldehyde for short time periods at low temperature in the presence of NaBH4. This result suggests that the Schiff base mechanism is operative since such treatment might be expected to inactivate the enzyme by reducing an iminium cation mechanistic intermediate. The inactivation process was shown to be highly specific for a single lysine residue. Incubation of phosphonatase with [3H]-NaBH4 and phosphonacetaldehyde [14C]-acetaldehyde and NaBH4 or [C2-3H]- phosphonoacetaldehyde and NaBH4 resulted in radiolabeled inactivated enzyme. Tryptic hydrolysis and reverse phase HPLC chromatography of the resulting digests demonstrated that the [C2 - 3H]- phosphonoacetaldehyde/NaBH4 methodology afforded the most specifically tritium labeled, inactivated phosphonatase. The radiolabeled, active site peptide was purified to homogeneity and its amino acid sequence was determined

  3. The oxidative fermentation of ethanol in Gluconacetobacter diazotrophicus is a two-step pathway catalyzed by a single enzyme: alcohol-aldehyde Dehydrogenase (ADHa).

    Gómez-Manzo, Saúl; Escamilla, José E; González-Valdez, Abigail; López-Velázquez, Gabriel; Vanoye-Carlo, América; Marcial-Quino, Jaime; de la Mora-de la Mora, Ignacio; Garcia-Torres, Itzhel; Enríquez-Flores, Sergio; Contreras-Zentella, Martha Lucinda; Arreguín-Espinosa, Roberto; Kroneck, Peter M H; Sosa-Torres, Martha Elena

    2015-01-01

    Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH) and the aldehyde dehydrogenase (ALDH). We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa) of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2-C6) and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde. PMID:25574602

  4. The Oxidative Fermentation of Ethanol in Gluconacetobacter diazotrophicus Is a Two-Step Pathway Catalyzed by a Single Enzyme: Alcohol-Aldehyde Dehydrogenase (ADHa

    Saúl Gómez-Manzo

    2015-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH and the aldehyde dehydrogenase (ALDH. We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2–C6 and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde.

  5. Design and development of a new generation of UV-visible-light-driven nanosized codoped titanium dioxide photocatalysts and biocides/sporocides, and environmental applications

    Hamal, Dambar B.

    For solar environmental remediation, a new generation of nanosized (carbon and sulfur) is necessary to achieve high-activities for acetaldehyde degradation under visible light (wavelength > 420 nm). It was concluded that high visible-light-activities for acetaldehyde degradation over codoped titanium dioxide were attributed to an interplay of anatase crystallinity, high-surface area, reduced band-gap (doped metal ions, and suppressed recombination rate of photogenerated electronhole pairs. Moreover, the nature and amount of codoped metals play a significant role in visible-light-induced photocatalysis. Metals (Al, Ga, and In) doped/codoped titanium dioxide photocatalysts were prepared by the aero-gel method. The photocatalytic studies showed that activities of metal doped/codoped photocatalysts under UV light (wavelength carbon, and sulfur codoped titanium dioxide nanoparticles ( 8) and B. subtilis spores (logarithmic kill > 5) for 30 minute exposures in dark conditions compared with Degussa P25. It was believed that the carbon and sulfur codoped titanium dioxide support and Ag species acted synergistically during deactivation of both E. coli and B. subtilis spores. Thus, titanium dioxide codoped with silver, carbon, sulfur can serve as a multifunctional generic biocide and a visible-light-active photocatalyst.

  6. Non-Catalytic and MgSO4 - Catalyst based Degradation of Glycerol in Subcritical and Supercritical Water Media

    Mahfud Mahfud

    2011-02-01

    Full Text Available This research aims to study the glycerol degradation reaction in subcritical and supercritical water media. The degradation of glycerol into other products was performed both with sulphate salt catalysts and without catalyst. The reactant was made from glycerol and water with the mass ratio of 1:10. The experiments were carried out using a batch reactor at a constant pressure of 250 kgf/cm2, with the temperature range of 200-400oC, reaction time of 30 minutes, and catalyst mol ratio in glycerol of 1:10 and 1:8. The products of the non-catalytic glycerol degradation were acetaldehyde, methanol, and ethanol. The use of sulphate salt as catalyst has high selectivity to acetaldehyde and still allows the formation alcohol product in small quantities. The mechanism of ionic reaction and free radical reaction can occur at lower temperature in hydrothermal area or subcritical water. Conversion of glycerol on catalytic reaction showed a higher yield when compared with the reaction performed without catalyst

  7. Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

    Kajos, M. K.; Rantala, P.; Hill, M.; Hellén, H.; Aalto, J.; Patokoski, J.; Taipale, R.; Hoerger, C. C.; Reimann, S.; Ruuskanen, T. M.; Rinne, J.; Petäjä, T.

    2015-04-01

    Proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography mass spectrometry GC-MS) allow real-time measurements of various atmospheric volatile organic compounds (VOC). By taking parallel measurements in ambient conditions, two PTR-MSs and two GC-MSs were studied for their ability to measure methanol, acetaldehyde, acetone, benzene and toluene. The measurements were conducted at a rural boreal forest site in southern Finland between 13 April and 14 May 2012. This paper presents correlations and possible biases between the concentrations measured using the four instruments. This paper presents correlations and possible biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds), while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively). For some compounds, notably for methane, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90). The systematic difference arises as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50-100% in the methanol emissions measured by commonly used methods.

  8. Sources, Sinks and Cycling of Acetyl Radicals in Tobacco Smoke: A Model for Biomass Burning Chemistry

    Hu, N.; Green, S. A.

    2012-12-01

    Smoke near the source of biomass burning contains high concentrations of reactive compounds, with NO and CH3CHO concentrations four to six orders of magnitude higher than those in the ambient atmosphere. Tobacco smoke represents a special case of biomass burning that is quite reproducible in the lab and may elucidate early processes in smoke from other sources. The origins, identities, and reactions of radical species in tobacco smoke are not well understood, despite decades of study on the concentrations and toxicities of the relatively stable compounds in smoke. We propose that reactions of NO2 and aldehydes are a primary source for transient free radicals in tobacco smoke, which contrasts with the long-surmised mechanism of reaction between NO2 and dienes. The objective of this study was to investigate the sources, sinks and cycling of acetyl radical in tobacco smoke. Experimentally, the production of acetyl radical was demonstrated both in tobacco smoke and in a simplified mixture of air combined with NO and acetaldehyde, both of which are significant components of smoke. Acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5-tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high performance liquid chromatography (HPLC), mass spectrometry/tandem mass spectrometry (MS-MS/MS) and liquid chromatography-mass spectrometry (LC-MS). The dynamic nature of radical cycling in smoke makes it impossible to define a fixed concentration of radical species; 2.15×e13-3.18×e14 molecules/cm3 of acetyl radicals were measured from different cigarette samples and smoking conditions. Matlab was employed to simulate reactions of NO, NO2, O2, and a simplified set of organic compounds known to be present in smoke, with a special emphasis on acetaldehyde and the acetyl radical. The NO2/acetaldehyde mechanism initiates a cascade of chain reactions, which accounts for the most prevalent known carbon-centered radicals found in

  9. Gas phase carbonyl compounds in ship emissions: Differences between diesel fuel and heavy fuel oil operation

    Reda, Ahmed A.; Schnelle-Kreis, J.; Orasche, J.; Abbaszade, G.; Lintelmann, J.; Arteaga-Salas, J. M.; Stengel, B.; Rabe, R.; Harndorf, H.; Sippula, O.; Streibel, T.; Zimmermann, R.

    2014-09-01

    Gas phase emission samples of carbonyl compounds (CCs) were collected from a research ship diesel engine at Rostock University, Germany. The ship engine was operated using two different types of fuels, heavy fuel oil (HFO) and diesel fuel (DF). Sampling of CCs was performed from diluted exhaust using cartridges and impingers. Both sampling methods involved the derivatization of CCs with 2,4-Dinitrophenylhydrazine (DNPH). The CCs-hydrazone derivatives were analyzed by two analytical techniques: High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) and Gas Chromatography-Selective Ion Monitoring-Mass Spectrometry (GC-SIM-MS). Analysis of DNPH cartridges by GC-SIM-MS method has resulted in the identification of 19 CCs in both fuel operations. These CCs include ten aliphatic aldehydes (formaldehyde, acetaldehyde, propanal, isobutanal, butanal, isopentanal, pentanal, hexanal, octanal, nonanal), three unsaturated aldehydes (acrolein, methacrolein, crotonaldehyde), three aromatic aldehyde (benzaldehyde, p-tolualdehyde, m,o-molualdehyde), two ketones (acetone, butanone) and one heterocyclic aldehyde (furfural). In general, all CCs under investigation were detected with higher emission factors in HFO than DF. The total carbonyl emission factor was determined and found to be 6050 and 2300 μg MJ-1 for the operation with HFO and DF respectively. Formaldehyde and acetaldehyde were found to be the dominant carbonyls in the gas phase of ship engine emission. Formaldehyde emissions factor varied from 3500 μg MJ-1 in HFO operation to 1540 μg MJ-1 in DF operation, which is 4-30 times higher than those of other carbonyls. Emission profile contribution of CCs showed also a different pattern between HFO and DF operation. The contribution of formaldehyde was found to be 58% of the emission profile of HFO and about 67% of the emission profile of DF. Acetaldehyde showed opposite behavior with higher contribution of 16% in HFO compared to 11% for DF. Heavier carbonyls

  10. Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity

    Lachenmeier Dirk W

    2008-11-01

    Full Text Available Abstract Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, pharmaceutical preparations, and many household products. Contradictory evidence about the safety of such topical applications of the alcohol can be found in the scientific literature, yet an up-to-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking. The first and foremost concerns of topical ethanol applications for public health are its carcinogenic effects, as there is unambiguous evidence for the carcinogenicity of ethanol orally consumed in the form of alcoholic beverages. So far there is a lack of evidence to associate topical ethanol use with an increased risk of skin cancer. Limited and conflicting epidemiological evidence is available on the link between the use of ethanol in the oral cavity in the form of mouthwashes or mouthrinses and oral cancer. Some studies pointed to an increased risk of oral cancer due to locally produced acetaldehyde, operating via a similar mechanism to that found after alcoholic beverage ingestion. In addition, topically applied ethanol acts as a skin penetration enhancer and may facilitate the transdermal absorption of xenobiotics (e.g. carcinogenic contaminants in cosmetic formulations. Ethanol use is associated with skin irritation or contact dermatitis, especially in humans with an aldehyde dehydrogenase (ALDH deficiency. After regular application of ethanol on the skin (e.g. in the form of hand disinfectants relatively low but measurable blood concentrations of ethanol and its metabolite acetaldehyde may occur, which are, however, below acute toxic levels. Only in children, especially through lacerated skin, can percutaneous toxicity occur. As there might be industry bias in many studies about the safety of topical ethanol applications, as well

  11. In situ measurements and modeling of reactive trace gases in a small biomass burning plume

    Müller, M.; Anderson, B.; Beyersdorf, A.; Crawford, J. H.; Diskin, G.; Eichler, P.; Fried, A.; Keutsch, F. N.; Mikoviny, T.; Thornhill, K. L.; Walega, J. G.; Weinheimer, A. J.; Yang, M.; Yokelson, R.; Wisthaler, A.

    2015-11-01

    An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin for deriving emission factors and followed ~ 13.6 km downwind for observing chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecedented spatio-temporal resolution (10 m/0.1 s). Quantitative emission data are reported for CO2, CO, NO, NO2, HONO, NH3 and 16 NMOGs (formaldehyde, methanol, acetonitrile, propene, acetaldehyde, formic acid, acetone plus its isomer propanal, acetic acid plus its isomer glycolaldehyde, furan, isoprene plus isomeric pentadienes and cyclopentene, methyl vinyl ketone plus its isomers crotonaldehyde and methacrolein, methylglyoxal, hydroxy acetone plus its isomers methyl acetate and propionic acid, benzene, 2,3-butandione and 2-furfural) with molar emission ratios relative to CO larger than 1 ppbV ppmV-1. Formaldehyde, acetaldehyde, 2-furfural and methanol dominated NMOG emissions. No NMOGs with more than 10 carbon atoms were observed at mixing ratios larger than 50 ppbV ppmV-1 CO emitted. Downwind plume chemistry was investigated using the observations and a 0-D photochemical box model simulation. The model was run on a near-explicit chemical mechanism (MCM v3.3) and initialized with measured emission data. Ozone formation during the first hour of atmospheric aging was well captured by the model, with carbonyls (formaldehyde, acetaldehyde, 2,3-butanedione, methylglyoxal, 2-furfural) in addition to CO and CH4 being the main drivers of peroxy radical chemistry. The model also accurately reproduced the sequestration of NOx into PAN and the OH-initiated degradation of furan and 2-furfural at an average OH concentration of 7.45 ± 1.07 × 106 cm-3 in the plume. Formaldehyde, acetone

  12. Infrared and reflectron time-of-flight mass spectroscopic analysis of methane (CH4)-carbon monoxide (CO) ices exposed to ionization radiation--toward the formation of carbonyl-bearing molecules in extraterrestrial ices.

    Kaiser, Ralf I; Maity, Surajit; Jones, Brant M

    2014-02-28

    Ice mixtures of methane and carbon monoxide were exposed to ionizing radiation in the form of energetic electrons at 5.5 K to investigate the formation of carbonyl bearing molecules in extraterrestrial ices. The radiation induced chemical processing of the mixed ices along with their isotopically labeled counterparts was probed online and in situ via infrared spectroscopy (solid state) aided with reflectron time-of-flight mass spectrometry (ReTOFMS) coupled to single photon photoionization (PI) at 10.49 eV (gas phase). Deconvolution of the carbonyl absorption feature centered at 1727 cm(-1) in the processed ices and subsequent kinetic fitting to the temporal growth of the newly formed species suggests the formation of acetaldehyde (CH3CHO) together with four key classes of carbonyl-bearing molecules: (i) alkyl aldehydes, (ii) alkyl ketones, (iii) α,β-unsaturated ketones/aldehydes and (iv) α,β,γ,δ-unsaturated ketones/α,β-dicarbonyl compounds in keto-enol form. The mechanistical studies indicate that acetaldehyde acts as the key building block of higher aldehydes (i) and ketones (ii) with unsaturated ketones/aldehydes (iii) and/or α,β-dicarbonyl compounds (iv) formed from the latter. Upon sublimation of the newly synthesized molecules, ReTOFMS together with isotopic shifts of the mass-to-charge ratios was exploited to identify eleven product classes containing molecules with up to six carbon atoms, which can be formally derived from C1-C5 hydrocarbons incorporating up to three carbon monoxide building blocks. The classes are (i) saturated aldehydes/ketones, (ii) unsaturated aldehydes/ketones, (iii) doubly unsaturated aldehydes/ketones, (iv) saturated dicarbonyls (aldehydes/ketones), (v) unsaturated dicarbonyls (aldehydes/ketones), (vi) saturated tricarbonyls (aldehydes/ketones), molecules containing (vii) one carbonyl - one alcohol (viii), two carbonyls - one alcohol, (ix) one carbonyl - two alcohol groups along with (x) alcohols and (xi) diols. Reaction

  13. The Amazonian Floodplains, an ecotype with challenging questions on volatile organic compound (VOC) emissions

    Kesselmeier, J.

    2012-12-01

    Volatile organic compound (VOC) emissions are affected by a variety of biotic and abiotic factors such as light intensity, temperature, CO2 and drought. Another factor usually overlooked but very important for the tropical rainforest in Amazonia is regular flooding. According to recent estimates, the total Amazonian floodplain area easily ranges up to 700,000 km^2, including whitewater river floodplains (várzea) blackwater regions (igapó) and further clearwater regions. Regarding the total Amazonian wetlands the area sums up to more than 2.000.000 km^2, i.e. 30% of Amazonia. To survive the flooding periods causing anoxic conditions for the root system of up to several months, vegetation has developed several morphological, anatomical and physiological strategies. One is to switch over the root metabolism to fermentation, thus producing ethanol as one of the main products. Ethanol is a toxic metabolite which is transported into the leaves by the transpiration stream. From there it can either be directly emitted into the atmosphere, or can be re-metabolized to acetaldehyde and/or acetate. All of these compounds are volatile enough to be partly released into the atmosphere. We observed emissions of ethanol, acetaldehyde and acetic acid under root anoxia. Furthermore, plant stress induced by flooding also affected leaf primary physiological processes as well as other VOC emissions such as the release of isoprenoids and other volatiles. For example, Hevea spruceana could be identified as a monoterpene emitting tree species behaving differently upon anoxia depending on the origin, with increasing emissions of the species from igapó and decreasing with the corresponding species from várzea. Contrasting such short term inundations, studies of VOC emissions under long term conditions (2-3 months) did not confirm the ethanol/acetaldehyde emissions, whereas emissions of other VOC species decreased considerably. These results demonstrate that the transfer of our knowledge

  14. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Teodora Emilia RUSU COLDEA

    2011-11-01

    Full Text Available In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear were characterized by gas-chromatography (GC-FID. There were collected 26 samples from different locations of Transylvania (Romania, all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, 2-butanol, iso-butylic alcohol, alcool amyl active, iso-amylic alcohol, 1-butanol and furfural. For each type of brandy, positive but no significant correlations between methanol and furfural concentrations in plum and apple brandy were noticed. To evaluate the differences in composition regarding the geographical origin of plum brandies and to analyze the composition of plum, apple and pear brandies it has been compared the mean values (MVP, MVA and MVPe obtained for each volatile. For plum brandies it has been observed differences among the mean values of each volatile, in samples originating from counties Cluj, Bistriţa-Năsăud and Maramureş. For methanol, acetaldehyde and 1-propanol the MVP Cluj values were significantly higher than MVP Bistriţa-Năsăud. For iso-butylic alcohol, amyl active alcohol, iso-amylic alcohol the MVP Cluj values were significantly higher than for Bistriţa-Năsăud and Maramureş, while for ethyl acetate and furfural the MVP Bistriţa-Năsăud were significantly higher than MVP Cluj and MVP Maramureş. When compared the mean values of volatiles in plum vs apple vs pear brandies, for ethyl acetate, methanol, 2-butanol, 1-propanol and 1-butanol, the MVPe values were significantly higher than MVA, for furfural, amyl active and iso-amylic alcohols, while for acetaldehyde the MVPe values were significantly higher than MVP. Methanol represented the major volatile component, characteristic to fruit brandies, released by enzymatic

  15. Citric acid reduces the decline in P300 amplitude induced by acute alcohol consumption in healthy adults

    Wei-xing CHEN; Chuan-qin XU; Shao-hua CHEN; Gen-yun XU; Huai-zhuang YE

    2012-01-01

    Event-related potential (ERP) is a reliable neuroelectric measure of brain activity that helps to confirm the assessment of mental status and cognitive impairment.Many studies have reported that alcoholics show a significantly lower ERP P300 amplitude than the norm.In the present study,ERP P300 waves were measured to evaluate the effect of citric acid on cognitive function during excessive alcohol consumption in healthy adults.Five volunteers were selected through clinical interview,physical examination,and psychiatric assessment for participation in this study.In a double-blind placebo-controlled before-after design,each subject was treated with 5 ml/kg body weight alcohol,5 ml/kg body weight alcohol and 1 mg citric acid,or a placebo on three separate occasions,one week apart.ERP P300,blood biochemical indicators,blood alcohol concentrations (BACs) and acetaldehyde concentrations were assessed.Repeated measure analysis of variance (ANOVA) with a within-subjects factor was used to evaluate differences in blood biochemical indicators,BACs,blood acetaldehyde concentrations,and ERP P300 in the three sessions of assessments.Several blood biochemical indicators showed significant differences between treatments,including the levels of cholinesterase (CHE),total bile acid (TBA),triglyceride (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C),very low-density lipoprotein cholesterol (VLDL-C),and glycylproline dipeptidyl aminopeptidase (GPDA).BACs after consumption of alcohol alone or citric acid with alcohol were significantly higher compared to those after placebo treatment (P<0.05).There were no significant differences in blood acetaldehyde concentrations between the treatments.The P300 amplitudes on the frontal (Fz),central (Cz),and parietal (Pz) regions of the scalp after consumption of alcohol were significantly lower than those after consumption of the placebo or citric acid with alcohol (P<0

  16. In situ measurements and modeling of reactive trace gases in a small biomass burning plume

    Müller, Markus; Anderson, Bruce E.; Beyersdorf, Andreas J.; Crawford, James H.; Diskin, Glenn S.; Eichler, Philipp; Fried, Alan; Keutsch, Frank N.; Mikoviny, Tomas; Thornhill, Kenneth L.; Walega, James G.; Weinheimer, Andrew J.; Yang, Melissa; Yokelson, Robert J.; Wisthaler, Armin

    2016-03-01

    An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin to derive emission factors and followed ˜ 13.6 km downwind to observe chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecedented spatiotemporal resolution (10 m spatial/0.1 s temporal). Quantitative emission data are reported for CO2, CO, NO, NO2, HONO, NH3, and 16 NMOGs (formaldehyde, methanol, acetonitrile, propene, acetaldehyde, formic acid, acetone plus its isomer propanal, acetic acid plus its isomer glycolaldehyde, furan, isoprene plus isomeric pentadienes and cyclopentene, methyl vinyl ketone plus its isomers crotonaldehyde and methacrolein, methylglyoxal, hydroxy acetone plus its isomers methyl acetate and propionic acid, benzene, 2,3-butanedione, and 2-furfural) with molar emission ratios relative to CO larger than 1 ppbV ppmV-1. Formaldehyde, acetaldehyde, 2-furfural, and methanol dominated NMOG emissions. No NMOGs with more than 10 carbon atoms were observed at mixing ratios larger than 50 pptV ppmV-1 CO. Downwind plume chemistry was investigated using the observations and a 0-D photochemical box model simulation. The model was run on a nearly explicit chemical mechanism (MCM v3.3) and initialized with measured emission data. Ozone formation during the first hour of atmospheric aging was well captured by the model, with carbonyls (formaldehyde, acetaldehyde, 2,3-butanedione, methylglyoxal, 2-furfural) in addition to CO and CH4 being the main drivers of peroxy radical chemistry. The model also accurately reproduced the sequestration of NOx into peroxyacetyl nitrate (PAN) and the OH-initiated degradation of furan and 2-furfural at an average OH concentration of 7.45 ± 1.07 × 106 cm-3 in the

  17. [Experimental research on alcohols, aldehydes, aromatic hydrocarbons and olefins emissions from alcohols fuelled vehicles].

    Zhang, Fan; Wang, Jian-Hai; Wang, Xiao-Cheng; Wang, Jian-Xin

    2013-07-01

    Using two vehicles fuelled with pure gasoline, M15, M30 and pure gasoline, E10, E20 separately, 25 degrees C normal temperature type I emission test, -7 degrees C low temperature type VI emission test and type IV evaporation emission test were carried out. FTIR, HPLC and GC-MS methods were utilized to measure alcohols, aldehydes, aromatic hydrocarbons and olefins emissions. The test results indicate that at the low as well as normal ambient temperature, as the alcohols proportion increasing in the fuel, unburned methanol, formaldehyde, acetaldehyde increase proportionally, benzene, toluene, ethylene, propylene, 1,3-butadiene and isobutene decrease slightly. The unregulated emissions at the low ambient temperature are significantly higher than those at the normal ambient temperature. The difference of HC emissions in the entire process of evaporative emission tests of E10, gasoline and M15 fuels is slight. There is a small difference of unregulated emissions in the diurnal test of three fuels. PMID:24027980

  18. Electrocatalytic activity of surface adsorbed ruthenium-alizarin complexone toward the oxidation of benzyl alcohol

    The surface electrochemical behavior of an adsorbed alizarin complexone (abbreviated as AC) and its surface coordination with Ru(II) were studied in aqueous solution at a pH range of 0-6. The surface complex of ruthenium with AC displays strong electrocatalytic activities toward benzyl alcohol. Based on the rotating disk electrode measurement, it is believed that the electrocatalytic oxidation of benzyl alcohol is a two-electron and two-proton process with benzaldehyde as a major product. On the other hand, ruthenium-AC surface complex has also shown catalytic activities toward electro-oxidation of several small organic molecules such as methanol, formic acid, formaldehyde, ethanol, and acetaldehyde

  19. Discovery and characterization of a xylose reductase from Zymomonas mobilis ZM4.

    Agrawal, Manoj; Chen, Rachel Ruizhen

    2011-11-01

    Formation of xylitol, a byproduct from xylose fermentation, is a major limiting factor in ethanol production from xylose in engineered Zymomonas strains, yet the postulated xylose reductase remains elusive. We report here the discovery of xylose reductase in Zymomonas mobilis and, for the first time, to associate the enzyme function with its gene. Besides xylose and xylulose, the enzyme was active towards benzaldehyde, furfural, 5-hydroxymethyl furfural, and acetaldehyde, exhibiting nearly 150-times higher affinity with benzaldehyde than xylose. The discovery of xylose reductase paves the way for further improvement of xylose fermentation in Z. mobilis. The enzyme may also be used to mitigate toxicity of furfural and other inhibitors from plant biomass. PMID:21720846

  20. Elastic and total cross sections for simple biomolecules in the intermediate energy range

    Gupta, Dhanoj; Naghma, Rahla; Antony, Bobby, E-mail: bka.ism@gmail.com [Atomic and Molecular Physics Lab, Department of Applied Physics, Indian School of Mines, Dhanbad 826004, JH (India)

    2015-09-15

    The elastic and total cross sections for formaldehyde, acetaldehyde, acetone, 2-butanone and formamide are calculated using the spherical complex optical potential formalism in the intermediate energy range from 50 eV to 10 keV. These cross sections find application to various fields like radiation damage and biological sciences. The present results are compared with the available experimental and theoretical data and are found to give excellent agreement. The elastic cross sections reported for most of the targets in the present energy range are done for the first time. The energy dependence of the contribution of ionization and elastic cross section with respect to the total cross section and the correlation of total cross section with polarizability of the molecules are also studied.

  1. Malodorous pollutants: a problem of public health

    Muzzi, A.; Tarsitani, G.

    1973-01-01

    The mechanism of odor perception in humans, the toxic, physiological, and psychic effects of malodorous substances, and possible ways of controlling malodorous emissions are surveyed. While many malodorous substances are toxic, when present in concentrations above the odor threshold they may cause nuisance, nausea, anorexia, and sleeplessness. Malodorous emissions are generated in the pulp and paper, petroleum refinery, fertilizer, detergent, resin, fiber and rubber production, metallurgical, pharmaceutical, paint, and food industries and by automobiles. Acetaldehyde, acetic and butyric acids, acrolein, dimethyl, trimethyl and monomethyl amines, chlorine, dimethyl sulfur, ethylacrylate, ethylmercaptan, phenol, methyl mercaptan, nitrobenzene, paracresol, pyridine, and styrene are among the industrial malodorous substances with the lowest odor thresholds. The nuisances due to malodorous emissions can be avoided by diluting the malodorous substances prior to emission. In most cases, however, effective odor control by scrubbing, absorption, adsorption, filtration, thermal incineration, or oxidation with chlorine, permanganate, or ozone are required.

  2. Natural Products for the Prevention and Treatment of Hangover and Alcohol Use Disorder.

    Wang, Fang; Li, Ya; Zhang, Yu-Jie; Zhou, Yue; Li, Sha; Li, Hua-Bin

    2016-01-01

    Alcoholic beverages such as beer, wine and spirits are widely consumed around the world. However, alcohol and its metabolite acetaldehyde are toxic and harmful to human beings. Chronic alcohol use disorder or occasional binge drinking can cause a wide range of health problems, such as hangover, liver damage and cancer. Some natural products such as traditional herbs, fruits, and vegetables might be potential dietary supplements or medicinal products for the prevention and treatment of the problems caused by excessive alcohol consumption. The aim of this review is to provide an overview of effective natural products for the prevention and treatment of hangover and alcohol use disorder, and special emphasis is paid to the possible functional component(s) and related mechanism(s) of action. PMID:26751438

  3. Natural Products for the Prevention and Treatment of Hangover and Alcohol Use Disorder

    Fang Wang

    2016-01-01

    Full Text Available Alcoholic beverages such as beer, wine and spirits are widely consumed around the world. However, alcohol and its metabolite acetaldehyde are toxic and harmful to human beings. Chronic alcohol use disorder or occasional binge drinking can cause a wide range of health problems, such as hangover, liver damage and cancer. Some natural products such as traditional herbs, fruits, and vegetables might be potential dietary supplements or medicinal products for the prevention and treatment of the problems caused by excessive alcohol consumption. The aim of this review is to provide an overview of effective natural products for the prevention and treatment of hangover and alcohol use disorder, and special emphasis is paid to the possible functional component(s and related mechanism(s of action.

  4. Indoor air pollution due to tobacco smoke under real conditions. Preliminary results.

    Klus, H; Begutter, H; Nowak, A; Pinterits, G; Ultsch, I; Wihlidal, H

    1985-08-01

    A short review exploring the generation and composition of tobacco smoke is given. Experimental arrangements used to record sidestream smoke are critically discussed. Data from own experiments in a tobacco smoke polluted office room were presented and discussed. These data include nicotine, ammonia, formaldehyde, acetaldehyde, hydrogen cyanide, CO, NO and NO2. First results about the diameter of the particles in the smoke polluted room were also given. By the aid of the RINGOLD's equation the COHB content on basis of the CO-values of exhaled breath of active and passive smokers were determined. Data about the nitrosamine content in the air of the room during the smoke tests were also given and discussed. PMID:3836513

  5. [Study of the effect of volatile metabolites of Trichoderma hamatum on the growth of phytopathogenic soilborne fungi.].

    Dal Bello, G M; Mónaco, C I; Cháves, A R

    1997-09-01

    Volatile compounds produced by Trichoderma hamatum were tested for their capacity to suppress in vitro the growth of Alternaria citri, Bipolaris cynodontis, Bipolaris sorokiniana, Curvularia brachyspora, Curvularia lunata, Curvularia oryzae-sativae, Drechslera tritici-repentis, Rhizoctonia solani, Sclerotinia minor and Sclerotium rolfsii. The organisms were cultured in an apparatus made with two Erlenmeyer flasks assembled by their top parts. With the aid of the gas chromatographic technique the variation of carbon dioxide, oxygen and ethylene in the internal system was determined. Acetaldehyde and ethanol were not found. Due to the respiratory metabolism of T. hamatum the carbon dioxide level progressively increased while the oxygen content decreased. Ethylene production was low and after three days remained constant. Excepting C. oryzae-sativae and B. cynodontis the other species showed changes in the growth and development. These results suggest the inhibitory volatiles of T. hamatum as one possible mechanism of biological control. PMID:17655390

  6. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  7. Spectral signatures for RDX-based explosives in the 3 micron region

    Osborn, Tabetha; Kaimal, Sindhu; Reeve, Scott W.; Burns, William

    2008-04-01

    Explosive compounds such as RDX, and HMX present significant challenges to optically based sensors. This difficulty is due in part to the low vapor pressures these compounds possess. One approach for sensing explosives that circumvents the low explosive vapor pressure problem, involves focusing on the trace amounts of relatively high vapor pressure impurities that will be present in the vapor signature. In order to effectively detect these volatile impurities, the spectral signature databases must be readily available. One of our goals therefore, is the generation of a database of high resolution spectral signatures for these volatile organic impurities. Some rather formidable spectroscopic measurement challenges have been encountered while working to extend the spectral signature effort to the 3 micron region. Here we will outline progress to date, with a focus on the volatile organic compounds formaldehyde, acetaldehyde, nitromethane, acetone, isobutene, and cyclohexanone.

  8. Acidity-controlled selective oxidation of alpha-pinene, isolated from Indonesian pine's turpentine oils (pinus merkusii)

    Masruri; Farid Rahman, Mohamad; Nurkam Ramadhan, Bagus

    2016-02-01

    Alpha-pinene was isolated in high purity from turpentine oil harvested from Pinus merkusii plantation. The recent investigation on selective oxidation of alpha-pinene using potassium permanganate was undertaken under acidic conditions. The result taught the selective oxidation of alpha-pinene in acidic using potassium permanganate lead to the formation of 2-(3-acetyl-2,2-dimethylcyclobutyl)acetaldehyde or pinon aldehyde. The study method applied reaction in various different buffer conditions i.e. pH 3, 4, 5, and 6, respectively, and each reaction product was monitored using TLC every hour. Product determination was undertaken on spectrometry basis such as infrared, ultra violet-visible, gas chromatography- and liquid chromatography-mass spectrometry.

  9. Evaluation of Ultra-Violet Photocatalytic Oxidation (UVPCO) forIndoor Air Applications: Conversion of Volatile Organic Compounds at LowPart-per-Billion Concentrations

    Hodgson, Alfred T.; Sullivan, Douglas P.; Fisk, William J.

    2005-09-30

    Efficient removal of indoor generated airborne particles and volatile organic compounds (VOCs) in office buildings and other large buildings may allow for a reduction in outdoor air supply rates with concomitant energy savings while still maintaining acceptable indoor air quality in these buildings. Ultra-Violet Photocatalytic Oxidation (UVPCO) air cleaners have the potential to achieve the necessary reductions in indoor VOC concentrations at relatively low cost. In this study, laboratory experiments were conducted with a scaled, prototype UVPCO device designed for use in a duct system. The experimental UVPCO contained two 30 by 30-cm honeycomb monoliths coated with titanium dioxide and 3% by weight tungsten oxide. The monoliths were irradiated with 12 UVC lamps arranged in four banks. The UVPCO was challenged with four mixtures of VOCs typical of mixtures encountered in indoor air. A synthetic office mixture contained 27 VOCs commonly measured in office buildings. A cleaning product mixture contained three cleaning products with high market shares. A building product mixture was created by combining sources including painted wallboard, composite wood products, carpet systems, and vinyl flooring. A fourth mixture contained formaldehyde and acetaldehyde. Steady-state concentrations were produced in a classroom laboratory or a 20-m{sup 3} environmental chamber. Air was drawn through the UVPCO, and single pass conversion efficiencies were measured from replicate air samples collected upstream and downstream of the reactor section. Concentrations of the mixtures were manipulated, with concentrations of individual VOCs mostly maintained below 10 ppb. Device flow rates were varied between 165 and 580 m{sup 3}/h. Production of formaldehyde, acetaldehyde, acetone, formic acid, and acetic acid as reaction products was investigated. Conversion efficiency data were generated for 48 individual VOCs or groups of closely related compounds. Alcohols and glycol ethers were the

  10. A DRIFTS study of the partial oxidation of ethanol on Rh catalysts

    The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and CexZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The catalysts were characterized by temperature-programmed reduction (TPR) and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH4 and H2 by decomposition. The presence of CeO2 in the catalysts favored the oxidation steps due to its oxygen storage capacity. (author)

  11. Electro-catalytic oxidation of ethanol on platinum-iridium mixtures supported on glassy carbon

    Electro-catalytic oxidation of ethanol on platinum-iridium mixtures supported on glassy carbon was studied, in acid media at different temperatures and concentrations. During the maturation time of deposited iridium, the surface is covered by an irreversible oxide formation, which affects the behavior of the catalytic mixture. The Pt70 Ir30 and Pt90 Ir10 mixtures seem to be a little more active than the Pt/C electrode at potentials below 800 mV (vs. HRE). In all electrodes appears two reactions: partial ethanol oxidation to produce acetaldehyde (main path of reaction at low temperatures and high electrode coverage with ethanol adsorption residues) and the total oxidation to carbon dioxide which is considerable at potential above 800 mV and it is increased with increasing temperature

  12. Research into aroma changes in irradiated foodstuffs. I.- Studies on Fish; Investigacion de Alteraciones de Aroma en alimentos irradiados. I Estudio sobre Pescado

    Barreiro Pinero, R.; Gasco Sanchez, L.; Valverde Garcia, F.

    1972-07-01

    Radiolytic formation of volatile compounds have been investigated in fillets of hake, codfish and bonito gamma-irradiated at a dose range of 0.1-5 Mrads. Analytical methods have been developed by gas chromatography of functional group derivatives: carbonyls as 2,4,-dinitrophenyl hydrazones, primary and secondary amines as N-alkyl benzamides, and thiols as 2,4-dinitrophenyl alkyl thioethers. The main results are as follows: increasing with the integral dose of the whole carbonyls, the most significant components being acetaldehyde, propional dehyde and formaldehyde; no significant variations with the integral dose od the traces of ammonia, methylamine, trimethylamine, ethylamine, diethylamine, propylamine, butylamine and pentylamine found in unirradiated samples; and radiolytic formation of methanethiol and dimethyl disulfide. (Author) 98 refs.

  13. Influence of Gold on Ce-Zr-Co Fluorite-Type Mixed Oxide Catalysts for Ethanol Steam Reforming

    Véronique Pitchon

    2012-02-01

    Full Text Available The effect of gold presence on carbon monoxide oxidation and ethanol steam reforming catalytic behavior of two Ce-Zr-Co mixed oxides catalysts with a constant Co charge and different Ce/Zr ratios was investigated. The Ce-Zr-Co mixed oxides were obtained by the pseudo sol-gel like method, based on metallic propionates polymerization and thermal decomposition, whereas the gold-supported Ce-Zr-Co mixed oxides catalysts were prepared using the direct anionic exchange. The catalysts were characterized using XRD, TPR, and EDXS-TEM. The presence of Au in doped Ce-Zr-Co oxide catalyst decreases the temperature necessary to reduce the cobalt and the cerium loaded in the catalyst and favors a different reaction pathway, improving the acetaldehyde route by ethanol dehydrogenation, instead of the ethylene route by ethanol dehydration or methane re-adsorption, thus increasing the catalytic activity and selectivity into hydrogen.

  14. Estudo da oxidação parcial do etanol em catalisadores de Rh por DRIFTS

    Raquel Lima Oliveira

    2013-01-01

    Full Text Available The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and Ce xZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS. The catalysts were characterized by temperature-programmed reduction (TPR and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH4 and H2 by decomposition. The presence of CeO2 in the catalysts favored the oxidation steps due to its oxygen storage capacity.

  15. A DRIFTS study of the partial oxidation of ethanol on Rh catalysts; Estudo da oxidacao parcial do etanol em catalisadores de Rh por DRIFTS

    Oliveira, Raquel Lima; Passos, Fabio Barboza, E-mail: fbpassos@vm.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Departamento de Engenharia Quimica e de Petroleo

    2013-09-01

    The partial oxidation of ethanol on {gamma}-Al{sub 2}O{sub 3}, CeO{sub 2}, ZrO{sub 2} and Ce{sub x}Zr{sub 1-x}O{sub 2} supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The catalysts were characterized by temperature-programmed reduction (TPR) and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH{sub 4} and H{sub 2} by decomposition. The presence of CeO{sub 2} in the catalysts favored the oxidation steps due to its oxygen storage capacity. (author)

  16. Estudo da oxidação parcial do etanol em catalisadores de Rh por DRIFTS A DRIFTS study of the partial oxidation of ethanol on Rh catalysts

    Raquel Lima Oliveira

    2013-01-01

    Full Text Available The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and Ce xZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS. The catalysts were characterized by temperature-programmed reduction (TPR and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH4 and H2 by decomposition. The presence of CeO2 in the catalysts favored the oxidation steps due to its oxygen storage capacity.

  17. Synthesis, characterization and catalytic properties of nanocrystaline Y{sub 2}O{sub 3}-coated TiO{sub 2} in the ethanol dehydration reaction

    Fajardo, Humberto Vieira [Universidade Federal de Ouro Preto (UFOP), MG (Brazil). Departamento de Quimica; Longo, Elson [Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Departamento de Fisico-Quimica; Leite, Edson Roberto; Libanori, Rafael [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica; Probst, Luiz Fernando Dias [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Departamento de Quimica; Carreno, Neftali Lenin Villarreal [Universidade Federal de Pelotas (UFPel), RS (Brazil). Departamento de Quimica Analitica e Inorganica

    2012-03-15

    In the present study, TiO{sub 2} nano powder was partially coated with Y{sub 2}O{sub 3} precursors generated by a sol-gel modified route. The system of nanocoated particles formed an ultra thin structure on the TiO{sub 2} surfaces. The modified nanoparticles were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) analysis, Zeta potential and surface area through N{sub 2} physisorption measurements. Bioethanol dehydration was used as a probe reaction to investigate the modifications on the nanoparticles surface. The process led to the obtainment of nanoparticles with important surface characteristics and catalytic behavior in the bioethanol dehydration reaction, with improved activity and particular selectivity in comparison to their non-coated analogs. The ethylene production was disfavored and selectivity toward acetaldehyde, hydrogen and ethane increased over modified nanoparticles. (author)

  18. Assessment of Pollutant Spread from a Building Basement with three Ventilation Systems

    Koffi, Juslin

    2010-01-01

    Ventilation aims at providing a sufficient air renewal for ensuring a good indoor air quality (IAQ), yet building energy policies are leading to adapting various ventilation strategies minimising energy losses through air renewal. A recent IAQ evaluation campaign in French dwellings shows important pollution of living spaces by VOCs such as formaldehyde, acetaldehyde or hexanal, particularly in buildings equipped with a garage. Besides, radon emission from soil is a subject of concern in many countries. Several studies are done to understand its release mode and deal with the spread of this carcinogen gas. This paper aims to experimentally assess a contaminant spread from a house basement using mechanical exhaust and balanced ventilation systems, and natural ventilation.

  19. [Effect of univalent cations on synthesis of surfactants by Acinetobacter calcoaceticus IMV B-7241].

    Pirog, T P; Shevchuk, T A; Antoniuk, S I; Kravchenko, E Iu; Iutinskaia, G A

    2013-01-01

    The effect of univalent cations on activity of key enzymes of C2-metabolism has been investigated in the producer of biosurfactants, Acinetibacter calcoaceticus IMV B-7241 grown on ethanol. It was established that potassium cations are inhibitors of pyroquinolinequinone-dependent alcohol- and acetaldehyde dehydrogenases, the enzymes of biosynthesis of surface-active aminolipids (NADP-dependent glutamate dehydrogenase) and glycolipids (phosphoenopyruvate (PhEP)-carboxikinase), while ammonium cations are activators of these enzymes and PhEP-carboxylase. A decrease of potassium cations concentration in the cultivation medium to 1 mM and increase of the content of amine nitrogen to 10 mM as a result of potassium nitrate substitution by equimolar, as to nitrogen, urea concentration were accompanied by the increase of activity of enzymes of ethanol metabolism and SAS biosynthesis, as well as by the 2-fold increase of conditional concentration of the biosurfactants. PMID:23720959

  20. Alcoholic cirrhosis and hepatocellular carcinoma.

    Stickel, Felix

    2015-01-01

    Hepatocellular carcinoma shows a rising incidence worldwide, and the largest burden of disease in Western countries derives from patients with alcoholic liver disease (ALD) and cirrhosis, the latter being the premier premalignant factor for HCC. The present chapter addresses key issues including the epidemiology of alcohol-associated HCC, and its link to other coexisting non-alcoholic liver diseases, and additional host and environmental risk factors including the underlying genetics. Also discussed are molecular mechanisms of alcohol-associated liver cancer evolution involving the mediators of alcohol toxicity and carcinogenicity, acetaldehyde and reactive oxygen species, as well as the recently described mutagenic adducts which these mediators form with DNA. Specifically, interference of alcohol with retinoids and cofactors of transmethylation processes are outlined. Information presented in this chapter illustrates that the development of HCC in the context of ALD is multifaceted and suggests several molecular targets for prevention and markers for the screening of risk groups. PMID:25427904

  1. Ethanol and neuronal metabolism.

    Mandel, P; Ledig, M; M'Paria, J R

    1980-01-01

    The effect of ethanol on membrane enzymes (Na+, K+ and Mg2+ ATPases, 5'-nucleotidase, adenylate cyclase) alcohol dehydrogenase, aldehyde dehydrogenase and superoxide dismutase were studied in nerve cells (established cell lines, primary cultures of chick and rat brain) cultured in the presence of 100 mM ethanol, and in total rat brain, following various ethanol treatments of the rats (20% ethanol as the sole liquid source, intraperitoneal injection). The results show a difference between neuronal and glial cells. Most of the observed changes in enzymatic activities returned rapidly to control values when ethanol was withdrawn from the culture medium or from the diet. Alcohol dehydrogenase was more stimulated by ethanol than aldehyde dehydrogenase; therefore acetaldehyde may be accumulated. The inhibition of superoxide dismutase activity may allow an accumulation of cytotoxic O2- radicals in nervous tissue and may explain the polymorphism of lesions brought about by alcohol intoxication. PMID:6264495

  2. Photochemistry of CO and H2O - Analysis of laboratory experiments and applications to the prebiotic earth's atmosphere

    Wen, Jun-Shan; Pinto, Joseph P.; Yung, Yuk L.

    1989-01-01

    The role photochemical reactions in the early earth's atmosphere played in the prebiotic synthesis of simple organic molecules was examined, extending an earlier calculation of formaldehyde production rates to more reduced carbon species, such as methanol, methane, and acetaldehyde. The experimental results of Bar-Nun and Chang (1983) are simulated as an aid in the construction of the photochemical scheme and as a way of validating the model. The results indicate that some fraction of CO2 and H2 present in the primitive atmosphere could have been converted to simple organic molecules. The exact amount is dependent on the partial pressure of CO2 and H2 in the atmosphere and on what assumptions are made concerning the shape of the absorption spectra of CO2 and H2O.

  3. Selecting ethanol as an ideal organic solvent probe in radiation chemistry γ-radiolysis of acetone-ethanol system and acetophenone-ethanol system

    Radiolysis of acetone-ethanol solution and acetophenone-ethanol solution has been studied in this work. The dependences of G values of the final γ radiolysis products such as H2. 2,3-butanediol and acetaldehyde on additive concentration in liquid ethanol have been obtained. There are two kinds of new final products, isopropanol and 2-methyl-2,3-butanediol are detected in irradiated acetone-ethanol solution. As for acetophenone-ethanol system, more new final products are found. In addition, experiments of pulse radiolysis upon acetophenone-ethanol solution have also been performed. The absorption spectrum with λ max at 315nm and 440nm is observed, which is assigned to ketyl radical ion C6H5(CH3)CO-. And the reaction mechanism of the two systems is proposed respectively with a moderate success. (author)

  4. Fermentative capabilities and volatile compounds produced by Kloeckera/Hanseniaspora and Saccharomyces yeast strains in pure and mixed cultures during Agave tequilana juice fermentation.

    González-Robles, Ivonne Wendolyne; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

    2015-09-01

    The fermentative and aromatic capabilities of Kloeckera africana/Hanseniaspora vineae K1, K. apiculata/H. uvarum K2, and Saccharomyces cerevisiae S1 and S2 were studied in pure and mixed culture fermentations using Agave tequila juice as the culture medium. In pure and mixed cultures, Kloeckera/Hanseniaspora strains showed limited growth and sugar consumption, as well as low ethanol yield and productivity, compared to S. cerevisiae, which yielded more biomass, ethanol and viable cell concentrations. In pure and mixed cultures, S. cerevisiae presented a similar behaviour reaching high biomass production, completely consuming the sugar, leading to high ethanol production. Furthermore, the presence of S. cerevisiae strains in the mixed cultures promoted the production of higher alcohols, acetaldehyde and ethyl esters, whereas Kloeckera/Hanseniaspora strains stimulated the production of ethyl acetate and 2-phenyl ethyl acetate compounds. PMID:26108494

  5. Matrix isolation investigation of the ozonolysis of propene

    Coleman, Bridgett E.; Ault, Bruce S.

    2010-07-01

    The matrix isolation technique, combined with infrared spectroscopy and merged jet deposition of ozone with propene led to the observation of "later", more stable products of this ozonolysis reaction. The observed products, specifically formaldehyde and acetaldehyde, are precisely the products predicted by the Criegee mechanism, formed by the two fragmentation pathways from the initial primary ozonide. Hence, the merged jet results strongly support the Criegee mechanism. In contrast, twin jet codeposition experiments followed by annealing led to no visible changes in the spectra. Subsequent irradiation of these twin jet matrices involving ozone with light of λ ⩾ 220 nm led to O atom production and subsequent reaction with propene. Multiple products were observed in these photochemical experiments. Extensive 18O isotopic labeling experiments, comparisons with literature spectra, and detailed theoretical calculations at the B3LYP/6-311++G(d,2p) level provided important supporting data.

  6. Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

    Akira Yasutake

    2011-01-01

    Full Text Available A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air over the contaminated area provided evidence of the mercury transformation to volatile Hg(0. Mercury analysis of soil and plant samples demonstrated that the mercury concentrations in soil with vaporized and plant-absorbable forms were higher in the southern area, which was closer to the factory. Our results suggest that air monitoring using a portable mercury analyzer can be a convenient and useful method for the rapid detection and mapping of mercury pollution in advanced field surveys.

  7. Naphthalene decomposition in a DC corona radical shower discharge

    Ming-jiang NI; Xu SHEN; Xiang GAO; Zu-liang WU; Hao LU; Zhong-shan LI; Zhong-yang LUO; Ke-fa CEN

    2011-01-01

    The naphthalene decomposition in a corona radical shower discharge (CRS) was investigated, with attention paid to the influences of voltage and initial naphthalene density. The OH emission spectra were investigated so as to know the naphthalene decomposing process. The by-products were analyzed and a decomposing theory in discharge was proposed. The results showed that higher voltage and relative humidity were effective on decomposition. The initial concentration affected the decomposing efficiency of naphthalene. When the mitial naphthalene density was 17 mg/m3, the decomposition rate was found to be 70% under 14 kV. The main by-products were carbon dioxide and water. However, a small amount of carbonic oxide, 1, 2-ethanediol and acetaldehyde were found due to the incomplete oxidization.

  8. The {gamma} radiolysis at room temperature of liquid deaerated isopropanol; Radiolyse {gamma} a temperature ambiante de l'isopropanol liquide desaere

    Gilles, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-02-01

    The main products formed in the room temperature {gamma} radiolysis of liquid isopropanol, and their respective yields, are: hydrogen 3.8, methane 1.6, acetone 3.4, acetaldehyde 1.1, and pinacol 0.3. These results give a material balance in good agreement with the formula of isopropanol and lead to a value for the yield of decomposition: 5, 3. The absence of butanediol 2.3 shows that the acetaldehyde cannot come from the dismutation of hydroxyethyl radicals. The variations of the hydrogen yield in the neutral medium with the concentration of added electron scavengers may be explained in terms of the model proposed by Freeman and FAYADH which supposes the existence of spurs. The yield of solvated electrons diffusing into the bulk of the solution and also the ratios of rate constants for the reactions of the scavengers with the electrons may likewise be obtained on the basis of this model. Certain effects not foreseen by this model may result from the capture of electrons solvated or not, whose mode of disappearance in pure alcohol remains unknown. One may distinguish a yield of excited molecules of at least 2, of which 80 per cent lead to the production of molecular hydrogen and 20 per cent to that of molecular methane, and an ionization yield of 2. 2. The discussion of the various mechanisms which may lead to the formation of the products indicates that these yields may be higher than the values quoted. (author) [French] Les principaux produits formes a temperature ambiante dans la radiolyse {gamma} de l'isopropanol liquide sont: l'hydrogene, le methane, l'acetone, l'acetaldehyde et le pinacol avec des rendements respectifs de 3,8 - 1,6 - 3,4 - 1,1 - 0,3. Le bilan de masse deduit de ces resultats est en bon accord avec la formule brute de l'isopropanol dont le rendement de decomposition est 5,3. L'absence de butanediol 2,3 montre que l'acetaldehyde ne peut provenir de la reaction de dismutation des radicaux hydroxyethyles. Le

  9. Enhanced photocatalytic activity for degrading pollutants of g-C3N4 by promoting oxygen adsorption after H3BO3 modification

    Li, Chengming; Raziq, Fazal; Liu, Chong; Li, Zhijun; Sun, Liqun; Jing, Liqiang

    2015-12-01

    The g-C3N4 has been modified by a hydrothermal post treatment with orthoboric acid. It is shown that the surface modification with an appropriate amount of orthoboric acid obviously enhances the surface photovoltage responses of g-C3N4, clearly indicating that the separation of photogenerated charges is greatly improved. This is well responsible for the enhanced photocatalytic activities for degrading representative gas-phase acetaldehyde, and liquid-phase phenol. Moreover, it is demonstrated that the amount of O2 adsorbed on the surfaces of g-C3N4 is greatly increased after H3BO3 modification based on the O2 temperature-programmed desorption curves. It is suggested that the orthoboric acid modification favors O2 adsorption to promote the photogenerated electrons captured for improved photocatalytic activities. This work would provide feasible routes to further improve the photocatalytic performance of semiconductors for degrading pollutants.

  10. Spittlebug impacts on sugarcane quality and ethanol production

    Gisele Cristina Ravaneli

    2011-02-01

    Full Text Available The objective of this work was to evaluate the impacts of spittlebug (Mahanarva fimbriolata attack on sugarcane quality and ethanol production. Technological and microbiological parameters of juice and fermentation process were evaluated in ten fermentation cycles and two harvest seasons. Treatments consisted of different spittlebug stalk damage levels: control, with 100% of apparently healthy stalks; medium, with 15% of damaged or dry stalks (DDS; high, with 30% of DDS; and very high, with 60% of DDS. Spittlebug attack caused significant losses in cane quality, reducing total soluble solids, sucrose content, total reducing sugars, and pH, and increasing total phenolic compounds, and total and volatile juice acidity. The fermentation process was also significantly affected, resulting in lower ethanol content in wine. There was an increase in acetaldehyde concentration in the distillate. The spittlebug attack caused negative impacts on sugarcane quality and fermentation process, and these impacts are stronger in late season harvests.

  11. Bioethanol Production Optimization: A Thermodynamic Analysis

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

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

  12. Effects of high CO₂ levels on fermentation, peroxidation, and cellular water stress in Fragaria vesca stored at low temperature in conditions of unlimited O₂.

    Blanch, Maria; Rosales, Raquel; Mateos, Raquel; Perez-Gago, María B; Sanchez-Ballesta, Maria T; Escribano, María I; Merodio, Carmen

    2015-01-28

    To better understand the tolerance of strawberries (Fragaria vesca L.) to high CO2 in storage atmospheres, fermentation and cellular damage were investigated. Fruits were stored for 3 and 6 days at 0 °C in the presence of different CO2 levels (0, 20, or 40%) with 20% O2. Changes in pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) gene expression and in fermentative metabolites, as well as in bound water and malondialdehyde (MDA) concentrations, were analyzed. In strawberries stored without added CO2, up-regulation of PDC and ADH was not associated with an increase in fermentative metabolites. By contrast, moderate ethanol fermentation in fruits exposed to 20% CO2 seems to be essential to maintain fruit metabolism, reducing both lipid peroxidation and cellular water stress. However, if the CO2 concentration increases (40%), the excess acetaldehyde and ethanol produced were closely correlated with a decrease in bound water and production of MDA. PMID:25568930

  13. Research into aroma changes in irradiated foodstuffs. I.- Studies on Fish

    Radiolytic formation of volatile compounds have been investigated in fillets of hake, codfish and bonito gamma-irradiated at a dose range of 0.1-5 Mrads. Analytical methods have been developed by gas chromatography of functional group derivatives: carbonyls as 2,4,-dinitrophenyl hydrazones, primary and secondary amines as N-alkyl benzamides, and thiols as 2,4-dinitrophenyl alkyl thioethers. The main results are as follows: increasing with the integral dose of the whole carbonyls, the most significant components being acetaldehyde, propional dehyde and formaldehyde; no significant variations with the integral dose od the traces of ammonia, methylamine, trimethylamine, ethylamine, diethylamine, propylamine, butylamine and pentylamine found in unirradiated samples; and radiolytic formation of methanethiol and dimethyl disulfide. (Author) 98 refs

  14. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae: new amides and phenolic compounds

    Ana Lígia Leandrini de Oliveira

    2012-01-01

    Full Text Available This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl-benzamide (0.019% and N,4-dihydroxy-N-(2'-hydroxyethyl-benzeneacetamide (0.023%. These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family.

  15. Expression, crystallization and preliminary X-ray crystallographic study of ethanolamine ammonia-lyase from Escherichia coli

    Ethanolamine ammonia-lyase from E. coli has been overexpressed, purified and crystallized. The crystals diffracted to 2.2 Å resolution using synchrotron radiation. Ethanolamine ammonia-lyase (EAL) catalyzes the adenosylcobalamin-dependent conversion of ethanolamine to acetaldehyde and ammonia. The wild-type enzyme shows a very low solubility. N-terminal truncation of the Escherichia coli EAL β-subunit dramatically increases the solubility of the enzyme without altering its catalytic properties. Two deletion mutants of the enzyme [EAL(βΔ4–30) and EAL(βΔ4–43)] have been overexpressed, purified and crystallized using the sitting-drop vapour-diffusion method. Crystals of EAL(βΔ4–30) and EAL(βΔ4–43) diffracted to approximately 8.0 and 2.1 Å resolution, respectively

  16. Ethanolamine utilization in Vibrio alginolyticus

    Khatri Neelam

    2012-12-01

    Full Text Available Abstract Ethanolamine is used as an energy source by phylogenetically diverse bacteria including pathogens, by the concerted action of proteins from the eut-operon. Previous studies have revealed the presence of eutBC genes encoding ethanolamine-ammonia lyase, a key enzyme that breaks ethanolamine into acetaldehyde and ammonia, in about 100 bacterial genomes including members of gamma-proteobacteria. However, ethanolamine utilization has not been reported for any member of the Vibrio genus. Our comparative genomics study reveals the presence of genes that are involved in ethanolamine utilization in several Vibrio species. Using Vibrio alginolyticus as a model system we demonstrate that ethanolamine is better utilized as a nitrogen source than as a carbon source. Reviewers This article was reviewed by Dr. Lakshminarayan Iyer and Dr. Vivek Anantharaman (nominated by Dr. L Aravind.

  17. Synthesis, characterization and catalytic properties of nanocrystaline Y2O3-coated TiO2 in the ethanol dehydration reaction

    In the present study, TiO2 nano powder was partially coated with Y2O3 precursors generated by a sol-gel modified route. The system of nanocoated particles formed an ultra thin structure on the TiO2 surfaces. The modified nanoparticles were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) analysis, Zeta potential and surface area through N2 physisorption measurements. Bioethanol dehydration was used as a probe reaction to investigate the modifications on the nanoparticles surface. The process led to the obtainment of nanoparticles with important surface characteristics and catalytic behavior in the bioethanol dehydration reaction, with improved activity and particular selectivity in comparison to their non-coated analogs. The ethylene production was disfavored and selectivity toward acetaldehyde, hydrogen and ethane increased over modified nanoparticles. (author)

  18. Mutations Closer to the Active Site Improve the Promiscuous Aldolase Activity of 4-Oxalocrotonate Tautomerase More Effectively than Distant Mutations.

    Rahimi, Mehran; van der Meer, Jan-Ytzen; Geertsema, Edzard M; Poddar, Harshwardhan; Baas, Bert-Jan; Poelarends, Gerrit J

    2016-07-01

    The enzyme 4-oxalocrotonate tautomerase (4-OT), which catalyzes enol-keto tautomerization as part of a degradative pathway for aromatic hydrocarbons, promiscuously catalyzes various carbon-carbon bond-forming reactions. These include the aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde. Here, we demonstrate that 4-OT can be engineered into a more efficient aldolase for this condensation reaction, with a >5000-fold improvement in catalytic efficiency (kcat /Km ) and a >10(7) -fold change in reaction specificity, by exploring small libraries in which only "hotspots" are varied. The hotspots were identified by systematic mutagenesis (covering each residue), followed by a screen for single mutations that give a strong improvement in the desired aldolase activity. All beneficial mutations were near the active site of 4-OT, thus underpinning the notion that new catalytic activities of a promiscuous enzyme are more effectively enhanced by mutations close to the active site. PMID:27238293

  19. Study of compounds emitted during thermo-oxidative decomposition of polyester fabrics

    Dzięcioł Małgorzata

    2016-03-01

    Full Text Available Compounds emitted during thermo-oxidative decomposition of three commercial polyester fabrics for indoor outfit and decorations (upholstery, curtains were studied. The experiments were carried out in a flow tubular furnace at 600°C in an air atmosphere. During decomposition process the complex mixtures of volatile and solid compounds were emitted. The main volatile products were carbon oxides, benzene, acetaldehyde, vinyl benzoate and acetophe-none. The emitted solid compounds consisted mainly of aromatic carboxylic acids and its derivatives, among which the greatest part took terephthalic acid, monovinyl terephthalate and benzoic acid. The small amounts of polycyclic aromatic hydrocarbons were also emitted. The emission profiles of the tested polyester fabrics were similar. The presence of toxic compounds indicates the possibility of serious hazard for people during fire.

  20. Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng;

    2014-01-01

    With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite-1 is reported and their high...... activity and selectivity for the catalytic gas-phase oxidation of ethanol are demonstrated. The zeolites are modified by a recrystallization process, which creates intraparticle voids and mesopores that facilitate the formation of small and disperse nanoparticles upon simple impregnation. The individual...... zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2-3nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50% conversion of ethanol with 98...

  1. Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng;

    2014-01-01

    With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite‐1 is reported and their high...... activity and selectivity for the catalytic gas‐phase oxidation of ethanol are demonstrated. The zeolites are modified by a recrystallization process, which creates intraparticle voids and mesopores that facilitate the formation of small and disperse nanoparticles upon simple impregnation. The individual...... zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2–3 nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50 % conversion of ethanol with 98...

  2. Influence of iodine on the treatment of spacecraft humidity condensate to produce potable water

    Symons, James M.; Muckle, Susan V.

    1990-01-01

    Several compounds in the ersatz humidity condensate do react with iodine to form iodine-substituted organic compounds (TOI), most notably phenol, acetaldehyde, ethanol, and sodium formate. Iodination of the ersatz humidity condensate produced 3.0 to 3.5 mg/L of TOI within 24 hours. The TOI that was produced by the passage of the ersatz humidity condensate through the first iodinated resin (IR) in the adsorption system was removed by the granular activated carbon that followed. TOI detected in the final effluent was formed by the reaction of the non-adsorbable condensate compounds with the final IR in the treatment series. The activated carbon bed series in the adsorption system performed poorly in its removal of TOC. The rapid breakthrough of TOC was not surprising, as the ersatz humidity condensate contained several highly soluble organic compounds, alcohols and organic acids.

  3. A fração volátil das aguardentes de cana produzidas no Brasil

    Ricardo F. A. Moreira

    2012-01-01

    Full Text Available The volatile fraction of sugar cane spirits plays a key role in the quality and acceptance of these beverages. The composition of this fraction is dependent on the way sugar cane collection, fermentation, distillation and aging are carried out. The materials used in these processes strongly influence chemical composition. Acetic acid, acetaldehyde, ethyl acetate, ethanol, 2.3-butanedione, n-propanol, 3-methyl-buthanol and isobuthanol were the major volatiles in spirits. Dimethyl sulfide and n-propanol impaired beverage flavor. Ethyl octanoate, 1.1-diethoxy-ethane, 2-phenylethanol and 3-methyl-butanol were important aroma contributors. Ageing allows the extraction of flavor-active components (e.g., phenolic compounds from wood.

  4. Characterization of volatile compounds of “Drenja”, an alcoholic beverage obtained from the fruits of cornelian cherry

    VELE TEŠEVIĆ

    2009-02-01

    Full Text Available In this study, volatile compounds were analyzed in five samples of home-made spirit beverage made by the distillation of fermented fruits of cornelian cherry (Cornus mas L.. The major volatile compounds, besides ethanol, identified and quantified were: methanol, acetaldehyde, 1-propanol, ethyl acetate, 2-methyl-1-propanol, 1-butanol, amyl alcohols, 1-hexanol and 2-phenylethanol. The minor volatiles were submitted to liquid–liquid extraction with dichloromethane and analyzed by gas chromatography and gas chromatography/ /mass spectrometry (GC/MS. A total of 84 compounds were identified. The most abundant compounds were straight-chain free fatty acids, ethyl esters of C6–C18 acids, limonene, 2-phenylethanol and 4-ethylphenol. Most of the compounds found in the “Drenja” spirits investigated in this study are similar to those present in other alcoholic beverages.

  5. DNA adducts-chemical addons

    T R Rajalakshmi

    2015-01-01

    Full Text Available DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde. This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers.

  6. DNA adducts-chemical addons.

    Rajalakshmi, T R; AravindhaBabu, N; Shanmugam, K T; Masthan, K M K

    2015-04-01

    DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde). This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers. PMID:26015708

  7. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

    This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family. (author)

  8. Photodissociation of CH3CHO at 248 nm by time-resolved Fourier-transform infrared emission spectroscopy: Verification of roaming and triple fragmentation

    Hung, Kai-Chan; Tsai, Po-Yu; Li, Hou-Kuan; Lin, King-Chuen

    2014-02-01

    By using time-resolved Fourier-transform infrared emission spectroscopy, the HCO fragment dissociated from acetaldehyde (CH3CHO) at 248 nm is found to partially decompose to H and CO. The fragment yields are enhanced by the Ar addition that facilitates the collision-induced internal conversion. The channels to CH2CO + H2 and CH3CO + H are not detected significantly. The rotational population distribution of CO, after removing the Ar collision effect, shows a bimodal feature comprising both low- and high-rotational (J) components, sharing a fraction of 19% and 81%, respectively, for the vibrational state v = 1. The low-J component is ascribed to both roaming pathway and triple fragmentation. They are determined to have a branching ratio of 0.06, respectively, relative to the whole v = 1 population. The CO roaming is accompanied by a highly vibrational population of CH4 that yields a vibrational bimodality.

  9. Low-temperature steam-reforming of ethanol over ZnO-supported Ni and Cu catalysts

    Homs, Narcis; Llorca, Jordi; De la Piscina, Pilar Ramirez [Departament de Quimica Inorganica, Universitat de Barcelona, C/Marti i Franques 1-11, 08028 Barcelona (Spain)

    2006-08-15

    ZnO-supported Ni and Cu as well as bimetallic Co-Ni and Co-Cu catalysts containing ca. 0.7wt% sodium promoter and prepared by the co-precipitation method were tested in the ethanol steam-reforming reaction at low temperature (523-723K), using a bioethanol-like mixture diluted in Ar. Monometallic ZnO-supported Cu or Ni samples do not exhibit good catalytic performance in the steam-reforming of ethanol for hydrogen production. Copper catalyst mainly dehydrogenates ethanol to acetaldehyde, whereas nickel catalyst favours ethanol decomposition. However, the addition of Ni to ZnO-supported cobalt has a positive effect both on the production of hydrogen at low temperature (<573K), and on catalyst stability. Evidence for alloy formation as well as mixed oxides at the microstructural level was found in the bimetallic systems after running the ethanol steam-reforming reaction by HRTEM-EELS. (author)

  10. A Doubles Correction to Electronic Excited States from Configuration Interaction in the Space of Single Substitutions

    Head-Gordon, Martin; Rico, Rudolph J.; Lee, Timothy J.; Oumi, Manabu

    1994-01-01

    A perturbative correction to the method of configuration interaction with single substitutions (CIS) is presented. This CIS(D) correction approximately introduces the effect of double substitutions which are absent in CIS excited states. CIS(D) is a second-order perturbation expansion of the coupled-cluster excited state method, restricted to single and double substitutions, in a series in which CIS is zeroth order, and the first-order correction vanishes. CIS (D) excitation energies are size consistent and the calculational complexity scales with the fifth power of molecular size, akin to second-order Moller-Plesset theory for the ground state. Calculations on singlet excited states of ethylene, formaldehyde, acetaldehyde, butadiene and benzene show that CIS (D) is a uniform improvement over CIS. CIS(D) appears to be a promising method for examining excited states of large molecules, where more accurate methods are not feasible.

  11. Ethanol consumption as inductor of pancreatitis

    José; A; Tapia; Ginés; M; Salido; Antonio; González

    2010-01-01

    Alcohol abuse is a major cause of pancreatitis, a condition that can manifest as both acute necroinflammation and chronic damage (acinar atrophy and f ibrosis). Pancreatic acinar cells can metabolize ethanol via the oxidative pathway, which generates acetaldehyde and involves the enzymes alcohol dehydrogenase and possibly cytochrome P4502E1. Additionally, ethanol can be metabolized via a nonoxidative pathway involving fatty acid ethyl ester synthases. Metabolism of ethanol by acinar and other pancreatic cells and the consequent generation of toxic metabolites, are postulated to play an important role in the development of alcohol-related acute and chronic pancreatic injury. This current work will review some recent advances in the knowledge about ethanol actions on the exocrine pancreas and its relationship to inflammatory disease and cancer.

  12. Theoretical study of partial oxidation of ethylene by vanadium trioxide cluster cation

    WANG ZheChen; DING XunLei; MA YanPing; CAO Hai; WU XiaoNan; ZHAO YanXia; HE ShengGui

    2009-01-01

    Density functional theory (DFT) study of reaction between vanadium trioxide cluster cation (VO+3) and ethylene (C2H4) to yield VO+2 + CH3CHO (acetaldehyde) and VO2CH+2 + HCHO (formaldehyde) is carried out.Structures of all reactants,products,intermediates,and transition state in the reaction have been optimized and characterized.The results show unexpected barriers in the reaction due to the existence of a η2-O2 moiety in the ground state structure of VO+3.The initial reaction steps combining ethylene adsorption,C=C activation and O-O cleavage are proposed as rate limiting processes.Comparison of reactions of VO+3 + C2H4 with VO3 + C2H4 and VO+2 + C2H4 in the previous studies is made in detail.The results of this work may shed light on the understanding of C=C bond cleavage in related heterogeneous catalysis.

  13. Palladium(II)-catalyzed oxidation of L-tryptophan by hexacyanoferrate(III) in perchloric acid medium: a kinetic and mechanistic approach

    Ahmed Fawzy

    2016-02-01

    The catalytic effect of palladium(II) on the oxidation of L-tryptophan by potassium hexacyanoferrate( III) has been investigated spectrophotometrically in aqueous perchloric acid medium. A first order dependence in [hexacyanoferrate(III)] and fractional-first order dependences in both [L-tryptophan] and [palladium(II)] were obtained. The reaction exhibits fractional-second order kinetics with respect to [H+]. Reaction rate increased with increase in ionic strength and dielectric constant of the medium. The effect of temperature on the reaction rate has also been studied and activation parameters have been evaluated and discussed. Initial addition of the reaction product, hexacyanoferrate(II), does not affect the rate significantly. A plausible mechanistic scheme explaining all the observed kinetic results has been proposed. The final oxidation products are identified as indole-3-acetaldehyde, ammonium ion and carbon dioxide. The rate law associated with the reaction mechanism is derived.

  14. The census of complex organic molecules in the solar type protostar IRAS16293-2422

    Jaber, Ali A; Kahane, C; Caux, E

    2014-01-01

    Complex Organic Molecules (COMs) are considered crucial molecules, since they are connected with organic chemistry, at the basis of the terrestrial life. More pragmatically, they are molecules in principle difficult to synthetize in the harsh interstellar environments and, therefore, a crucial test for astrochemical models. Current models assume that several COMs are synthesised on the lukewarm grain surfaces ($\\gtrsim$30-40 K), and released in the gas phase at dust temperatures $\\gtrsim$100 K. However, recent detections of COMs in $\\lesssim$20 K gas demonstrate that we still need important pieces to complete the puzzle of the COMs formation. We present here a complete census of the oxygen and nitrogen bearing COMs, previously detected in different ISM regions, towards the solar type protostar IRAS16293-2422. The census was obtained from the millimeter-submillimeter unbiased spectral survey TIMASSS. Six COMs, out of the 29 searched for, were detected: methyl cyanide, ketene, acetaldehyde, formamide, dimethyl ...

  15. Structure and photochemistry of the methanol complexes with methylglyoxal and diacetyl: FTIR matrix isolation and theoretical study

    Mucha, Malgorzata [Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw (Poland); Mielke, Zofia, E-mail: zm@wchuwr.pl [Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw (Poland)

    2009-06-30

    The FTIR spectra of the argon matrices doped with methanol and methylglyoxal or diacetyl have been studied. The matrices were irradiated with the output of medium pressure mercury lamp. The spectra analysis indicate the presence of hydrogen bonded complexes between methanol and {alpha}-dicarbonyl in solid argon. The structures of the complexes are established by the ab initio MP2/6-311++G(2d,2p) calculations. Methylglyoxal in solid argon subjected to {lambda} {>=} 395 nm radiation photodissociates mostly into carbon monoxide and methane but when it is exposed to the full output of mercury lamp acetaldehyde and carbon monoxide are the main photodissociation products. Irradiation of the methylglyoxal-methanol complex leads to its photo-conversion into the methylhydroxyketene-methanol complex.

  16. Formation Mechanism and Influencing Factors of Off-odor Compounds in High Fructose Syrup%果葡糖浆中异味化合物的形成机理及其影响因素研究

    叶晓蕾

    2012-01-01

    Acetaldehyde,isovaleraldehyde,2-aminoacetophenone,furfural and 5-hydroxymethylfurfural are off-odor compounds which have undesirable impact on flavor of high fructose syrup.The formation mechanism and influencing factors of the five compounds were discussed,so as to provide reference for production of high fructose syrup.%介绍了果葡糖浆中可能存在并对产品风味有潜在影响的5种异味化合物——乙醛、异戊醛、2-氨基乙酰苯、糠醛、5-羟甲基糠醛,阐述了其形成机理和影响因素,以期为果葡糖浆生产提供参考。

  17. Reaction pathways of model compounds of biomass-derived oxygenates on Fe/Ni bimetallic surfaces

    Yu, Weiting; Chen, Jingguang G.

    2015-10-01

    Controlling the activity and selectivity of converting biomass-derivatives to fuels and valuable chemicals is critical for the utilization of biomass feedstocks. There are primarily three classes of non-food competing biomass, cellulose, hemicellulose and lignin. In the current work, glycolaldehyde, furfural and acetaldehyde are studied as model compounds of the three classes of biomass-derivatives. Monometallic Ni(111) and monolayer (ML) Fe/Ni(111) bimetallic surfaces are studied for the reaction pathways of the three biomass surrogates. The ML Fe/Ni(111) surface is identified as an efficient surface for the conversion of biomass-derivatives from the combined results of density functional theory (DFT) calculations and temperature programmed desorption (TPD) experiments. A correlation is also established between the optimized adsorption geometry and experimental reaction pathways. These results should provide helpful insights in catalyst design for the upgrading and conversion of biomass.

  18. Estimation of gaseous mercury emissions in Germany. Inverse modelling of source strengths at the contaminated industrial site BSL Werk Schkopau

    Krueger, O.; Ebinghaus, R.; Kock, H.H.; Richter-Politz, I.; Geilhufe, C.

    1998-12-31

    Anthropogenic emission sources of gaseous mercury at the contaminated industrial site BSL Werk Schkopau have been determined by measurements and numerical modelling applying a local dispersion model. The investigations are based on measurements from several field campaigns in the period of time between December 1993 and June 1994. The estimation of the source strengths was performed by inverse modelling using measurements as constraints for the dispersion model. Model experiments confirmed the applicability of the inverse modelling procedure for the source strength estimation at BSL Werk Schkopau. At the factory premises investigated, the source strengths of four source areas, among them three closed chlor-alkali productions, one partly removed acetaldehyde factory and additionaly one still producing chlor-alkali factory have been identified with an approximate total gaseous mercury emission of lower than 2.5 kg/day. (orig.)

  19. Chemometric Characterization of Alembic and Industrial Sugar Cane Spirits from Cape Verde and Ceará, Brazil

    Regina F. R. Pereira

    2012-01-01

    Full Text Available Sugar cane spirits are some of the most popular alcoholic beverages consumed in Cape Verde. The sugar cane spirit industry in Cape Verde is based mainly on archaic practices that operate without supervision and without efficient control of the production process. The objective of this work was to evaluate samples of industrial and alembic sugar cane spirits from Cape Verde and Ceará, Brazil using principal component analysis. Thirty-two samples of spirits were analyzed, twenty from regions of the islands of Cape Verde and twelve from Ceará, Brazil. Of the samples obtained from Ceará, Brazil seven are alembic and five are industrial spirits. The components analyzed in these studies included the following: volatile organic compounds (n-propanol, isobutanol, isoamylic, higher alcohols, alcoholic grade, acetaldehyde, acetic acid, acetate; copper; and sulfates.

  20. Effect of calcination temperature on the photocatalytic properties of electrospun TiO2 nanofibers.

    Lee, Young-In; Lee, Jong-Sik; Park, Eun-Sil; Jang, Dae-Hwan; Lee, Jae-Eun; Kim, Kahee; Myung, Nosang V; Choa, Yong-Ho

    2014-10-01

    In this study, TiO2 nanofibers with a high aspect ratio and a large specific surface area were synthesized using the electrospinning technique, and the effect of calcination temperature on their crystal structure, diameter, specific surface area and photocatalytic activity was systematically investigated. The electrospun, as-prepared PVP/TTIP nanofibers were several tens of micrometers in length with a diameter of 74 nm. TiO2 nanofibers with an average diameter of 50 nm were prepared after calcination at various temperatures. The calcination temperature significantly influenced the photocatalytic and material properties of TiO2 including grain size and specific surface area. When compared to other nanostructured TiO2 materials, such as commercial TiO2 nanoparticles (P25, Degussa), the TiO2 nanofibers exhibited greater photocatalytic activity for the degradation of acetaldehyde and ammonia. PMID:25942911