Showing papers on "Acetic acid published in 1988"
TL;DR: In this paper, the photooxidation rate of 22 organic solutes over a UV illuminated film of Degussa P25 titanium dioxide was studied over a 100-fold concentration range for each solute, generally from about 1 to 100 mg liter−1.
476 citations
TL;DR: Tropospheric concentrations of formic and acetic acids in the gas, the aerosol, and the rainwater phases were determined in samples collected 1-2 m above ground level at an open field site in eastern Virginia.
Abstract: Tropospheric concentrations of formic and acetic acids in the gas, the aerosol, and the rainwater phases were determined in samples collected 1-2 m above ground level at an open field site in eastern Virginia. These acids were found to occur principally (98 percent or above) in the gas phase, with a marked annual seasonality, averaging 1890 ppt for formate and 1310 ppt for acetate during the growing season, as compared to 695 ppt and 700 ppt, respectively, over the nongrowing season. The data support the hypothesis that biogenic emissions from vegatation are important sources of atmospheric formic and acetic acid during the local growing season. The same time trends were observed for precipitation, although with less defined seasonality. The relative increase of the acetic acid/formic acid ratio during the nongrowing season points to the dominance of anthropogenic inputs of acetic acid from motor vehicles and biomass combustion in the wintertime.
341 citations
Patent•
BP1
TL;DR: In this article, an alcohol and/or a carboxylic acid ester is produced from an acid or anhydride by reacting the acid with hydrogen at elevated temperature in the presence as catalyst of a composition comprising an alloy of (i) at least one noble metal of Group VIII of the Periodic Table and (ii) one metal capable of alloying with the Group VIII noble metal.
Abstract: An alcohol and/or a carboxylic acid ester is produced from a carboxylic acid or anhydride thereof by reacting the acid or anhydride with hydrogen at elevated temperature in the presence as catalyst of a composition comprising an alloy of (i) at least one noble metal of Group VIII of the Periodic Table and (ii) at least one metal capable of alloying with the Group VIII noble metal, optionally including a support and at least one of the metals rhenium, tungsten or molybdenum The process is particularly applicable to the hydrogenation of monobasic acids, for example acetic acid, and the hydrogenation of maleic acid or maleic anhydride to gamma-butyrolactone
194 citations
TL;DR: In this article, the dimerization of (p-hydroxyphenyl)acetic acid by hydrogen peroxide in the presence of peroxidase has been adapted to the determination of HPO in seawater.
Abstract: The dimerization of (p-hydroxyphenyl)acetic acid by hydrogen peroxide in the presence of peroxidase has been adapted to the determination of hydrogen peroxide in seawater. The fluorometric method presented requires only one mixed reagent for sample analysis and produces a stable product that does not require immediate measurement. Changes in reaction stoichiometry resulting from naturally occurring organic material have been addressed. The detection limit, defined as 3 times the standard deviation of the blank, is 4 and 4 nM for open ocean and coastal seawater, respectively.
168 citations
TL;DR: In this paper, the authors investigated the activity of precious meta catalysts in the wet oxidation of organic compounds and found that Ruthenium was the most active catalyst among the precious metals examined, and cerium (IV) oxide is the most effective support.
Abstract: The activity of precious meta catalysts in the wet oxidation of organic compounds was investigated. Ruthenium was the most active catalyst among the precious metals examined, and cerium (IV) oxide was the most effective support. The Ru/Ce catalyst rivaled homogeneous copper catalyst, which is used in the practical wastewater treatment, for the oxidation of n-propyl alcohol, n-butyl alcohol, phenol, acetamide, poly (propylene glycol), and acetic acid. In addition, it was especially effective for the oxidation of some compounds with high oxygen content such as poly (ethylene glycol), ethylene glycol, formaldehyde, and formic acid.
166 citations
TL;DR: Transesterification reactions were found to be a good alternative way for esters synthesis and acetic acid esters were more difficult to obtain.
Abstract: Thirteen commercial lipase preparations were checked for their ability to catalyse the formation of flavour esters (isoamyl or geranyl acetate, propionate and butyrate) by either direct esterification or ester solvolysis in n-heptane. The formation of isoamyl or geranyl butyrates and propionates by direct esterification was catalyzed by the majority of the tested lipases. Acetic acid esters were more difficult to obtain. Transesterification reactions were found to be a good alternative way for ester synthesis.
148 citations
136 citations
TL;DR: In this article, the effect of soil organic matter on concentrations of metals in soil solution and their extractability from soil, solutions containing varying concentrations of Mn, Zn and Cu salts were added to five samples of a sandy loam soil with organic matter levels ranging from 0.8 to 2.4% C. Concentrations of the metals and their ions in solutions displaced from the samples after 3 weeks of incubation were determined.
127 citations
TL;DR: In this article, the results of methanol, ethanol, 1-propanol, and 2-Propanol were examined on a Pd(111) surface containing one-quarter monolayer of adsorbed oxygen atoms.
123 citations
TL;DR: It was demonstrated that acetic acid bacteria can be responsible for the onset of aerobic deterioration of maize silage and by monitoring the development of the microbiota of samples exposed to air, acetic Acid bacteria and yeasts often developed simultaneously in uninoculated silage samples exposure to air.
Abstract: Acetic acid bacteria were isolated from maize silages and from samples of maize silage exposed to air. The isolates apparently belonged to the genus Acetobacter. By inoculating maize silage with strains of acetic acid bacteria isolated from silage and by monitoring the development of the microbiota of samples exposed to air it was demonstrated that acetic acid bacteria can be responsible for the onset of aerobic deterioration of maize silage. However, acetic acid bacteria and yeasts often developed simultaneously in uninoculated silage samples exposed to air. In all experiments ethanol was oxidized to acetic acid followed by a rapid oxidation of lactic and acetic acids when ethanol was depleted.
120 citations
TL;DR: In this article, the self-association of acetic acid in organic solvents at 25 o C was investigated by infrared spectroscopy, using four Lorentzian curves.
Abstract: The self-association of acetic acid in organic solvents at 25 o C has been investigated by infrared spectroscopy. The organic solvents used are n-hexane, carbon tetrachloride, toluene, benzene, chlorobenzene, chloroform, 1,2-dichloroethane, and dichloromethane. The spectra of the carbonyl region were fitted with four Lorentzian curves, two for acetic acid monomer and cyclic dimer and the other two for the linear dimer
TL;DR: An acetyl esterase was purified from Trichoderma reesei by cation and anion exchange chromatography and showed activity towards naphthyl acetate, triacetin and glucose-and xylose acetates, but liberated acetic acid from acetylated xylo-oligomers only to a small extent.
Abstract: An acetyl esterase was purified from Trichoderma reesei by cation and anion exchange chromatography. The enzyme had a molecular weight of 45 000 as determined by SDS-electrophoresis, or 67 000 as determined by gel filtration. In chromatofocusing the enzyme was shown to consist of two isoenzymes with isoelectric points of 6.8 and 6.0. The enzyme showed activity towards naphthyl acetate, triacetin and glucose-and xylose acetates. However, it liberated acetic acid from acetylated xylo-oligomers only to a small extent. The liberation of acetic acid from the oligomeric substrate was enhanced by addition of endoxylanase and β-xylosidase.
TL;DR: In this paper, Fourier transform infrared spectroscopy (FTIR) was used to analyze the pyrolysis of wood at 250°C on a thermal balance and the evolved gases have been analyzed by FTIR for glycoses, uronic acids and nitrobenzene oxidation to vanillin and syringaldehyde.
TL;DR: In this article, the potential-dependent specific adsorption of acetic acid and acetate at polycrystalline platinum- and gold-aqueous interfaces has been examined by potential-difference infrared spectroscopy (PDIRS) in conjunction with quantitative surface concentration measurements using the radiotracer technique.
Abstract: The potential-dependent specific adsorption of acetic acid and acetate at polycrystalline platinum- and gold-aqueous interfaces has been examined by potential-difference infrared spectroscopy (PDIRS) in conjunction with quantitative surface concentration measurements using the radiotracer technique. Both the infrared and radiotracer measurements utilize a similar thin-layer solution arrangement. Extensive adsorption of acetic acid occurs at both platinum and gold, which increases at more positive potentials and reaches a maximum at the onset of anodic oxide formation. The PDIR spectra contain several features identified with solution acetic acid in the 1200-1800-cm/sup -1/ region, including v/sub C==O/ and v/sub C-O/ bands at 1710 and 1280 cm/sup -1/, respectively, arising from adsorption-induced changes in the thin-layer solution composition as well as a single band, at 1415 and 1400 cm/sup -1/ on platinum and gold, restively, due to adsorbed acetic acid. The intensity of the former bands can by employed to evaluate the extent of adsorption as a function of potential; the results are in semiquantitative agreement with the surface concentration-potential data from radiotracer measurements. In view of the infrared spectra together with the observed absence of acetate adsorption, the most likely modes of acetic acid adsorption involve hydrogen bonding between the carbonyl oxygen and inner-layermore » water molecules, of by self-association to form dimers or chain structures« less
TL;DR: In this paper, ionically crosslinked polyacrylic acid (PAA) and Nylon 6 membranes were used for the pervaporation separation of acetic acid-water mixtures.
Abstract: Membranes consisting of ionically crosslinked polyacrylic acid (PAA) and Nylon 6 were prepared and tested for the pervaporation separation of acetic acid-water mixtures. The polyacrylic acid (PAA) membranes were crosslinked in aluminum nitrate aqueous solution while the polyacrylic acid (PAA)-Nylon 6 blends were cast from homogeneous PAA-Nylon 6 mixtures to appropriate thicknesses and then crosslinked in aqueous aluminum nitrate solutions. Optimum pervaporation results were obtained from blends of Nylon 6 and PAA in the weight ratio of 60–75 wt% Nylon 6 and 25–40 wt% PAA which have separation factors (water/acetic acid) of over 60 and flux rates higher than 100 g/m2 h at 15°C for the separation of acetic acid-water mixtures. The flux rates and separation factors could be altered by changing the blend composition of the membrane. The effects of the feed composition on the separation factors were investigated.
TL;DR: In this article, the final conversion yield of glucose into butanol could be increased from 20% to 30% by iron limitation, and the acetonebutanol ratio was changed from 3.7 (control) to 11.8.
Abstract: WhenClostridium acetobutylicum was grown in batch culture under iron limitation (0.2 mg·l−1) at a pH of 4.8, glucose was fermented, to butanol as the major fermentation end product, and small quantities of acetic acid were produced. The final conversion yield of glucose into butanol could be increased from 20% to 30% by iron limitation. The acetonebutanol ratio was changed from 3.7 (control) to 11.8. Hydrogenase specific activity was decreased by 40% and acetoacetate decarboxylase specific activity by 25% under iron limitation. Thus, iron limitation affects carbon and electron flow in addition to hydrogenase.
01 Jan 1988
TL;DR: The highest levels of aerosol formate and acetate were found in haze layers derived from biomass burning as mentioned in this paper, where they represented about one half of the anion equivalents in precipitation, in contrast to the atmospheric aerosol, where they contributed less than 10% of the soluble anionic equivalents.
Abstract: formic and acetic acid in the gas phase were about 2 orders of magnitude higher than concentrations of the corresponding species in the atmospheric aerosol. About 50-60% of the aerosol (total) formate and acetate were in the size fraction below 1.0 #m diameter. The highest levels of aerosol formate and acetate were found in haze layers derived from biomass burning. In precipitation, (total) formate and acetate represented about one half of the anion equivalents. This is in contrast to the atmospheric aerosol, where they contributed less than 10% of the soluble anionic equivalents. Furthermore, the precipitation contained considerable acidity (average 36 #eq L - during the study period), again in contrast to the aerosol, which was acid-base neutral. The mean hydrogen ion concentration in rain was about 21-26 #eq L- (pH 4.6-4.7). Most of the precipitation acidity can be attributed to the organic acids, with sulfuric and nitric acids contributing only about 10-20% of the hydrogen ion concentration. Aerosol scavenging can explain only a small fraction of the observed amounts of formate and acetate in rain. The observed levels of these ions in rain are most likely the result of a combination of chemical reactions in hydrometeors and scavenging of the gaseous acids by cloud droplets.
TL;DR: Aqueous solutions of CO2 containing tetramethylammonium chloride were photolysed with visible light in the presence of colloidal CdS to yield glyoxylic acid as well as formic and acetic acids and CH2O.
Abstract: Aqueous solutions of CO2 containing tetramethylammonium chloride were photolysed with visible light in the presence of colloidal CdS to yield glyoxylic acid as well as formic and acetic acids and CH2O.
Patent•
10 Jun 1988TL;DR: A process for the higher selective production of acetic acid by the catalytic oxidation with oxygen of ethane, or ethylene, or mixtures thereof, in contact with a mixed catalyst composition containing a calcined mixed oxides catalyst of the formula: MoxVyZz wherein Z represents nothing or a metal from a group of metals as hereinafter defined as mentioned in this paper.
Abstract: ACETIC ACID FROM ETHANE, ETHYLENE AND OXYGEN Abstract of the Disclosure A process for the higher selective production of acetic acid by the catalytic oxidation with oxygen of ethane, or ethylene, or mixtures thereof, in contact with a mixed catalyst composition containing (A) a calcined mixed oxides catalyst of the formula: MoxVyZz wherein Z represents nothing or a metal from a group of metals as hereinafter defined and (B) is an ethylene hydration catalyst and/or an ethylene oxidation catalyst.
TL;DR: The electrodialysis fermentation system resulted in improved cell growth and higher productivity over an extended period; the productivity exceeded that from non-pH-controlled fermentation.
Abstract: In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth and higher productivity over an extended period; the productivity exceeded that from non-pH-controlled fermentation. During electrodialysis fermentation in our system, 97.6 g of acetic acid was produced from 86.0 g of ethanol; the amount of acetic acid was about 2.4 times greater than that produced by non-pH-controlled fermentation (40.1 g of acetic acid produced from 33.8 g of ethanol). Maximum productivity of electrodialysis fermentation in our system was 2.13 g/h, a rate which was 1.35 times higher than that of non-pH-controlled fermentation (1.58 g/h).
TL;DR: The effect of acetic acid and vinegar (in which the major component is acetic Acid) on the blood glucose response was examined.
Abstract: (1988). Effect of Acetic Acid and Vinegar on Blood Glucose and Insulin Responses to Orally Administered Sucrose and Starch. Agricultural and Biological Chemistry: Vol. 52, No. 5, pp. 1311-1312.
TL;DR: Reduction of glycals and didesoxy-2,3 hexeno-2pyranosides; application a la synthese du compose du titre a partir de di-O-acetyl rhamnal.
Abstract: Reduction de glycals et de didesoxy-2,3 hexeno-2pyranosides; application a la synthese du compose du titre a partir de di-O-acetyl rhamnal
TL;DR: Normal phase high performance liquid chromatography methods are described for the separation of neutral lipid, fatty acid and five phospholipid classes using spectrophotometric detection at 206 nm and recoveries of oleic acid and cholesterol were 100% and 97%, respectively.
Abstract: Normal phase high performance liquid chromatography methods are described for the separation of neutral lipid, fatty acid and five phospholipid classes using spectrophotometric detection at 206 nm. Separations were accomplished in less than 10 min for each lipid class. A mobile phase consisting of hexane/methyltertiarybutylether/acetic acid (100∶5∶0.02) proved effective in separating cholesteryl ester and triglyceride with recoveries of 100% for radiolabeled cholesteryl oleate and 98% for radiolabeled triolein. Free fatty acid and cholesterol were separated by two different mobile phases. The first, hexane/methyltertiarybutylether/acetic acid (70∶30∶0.02) effectively separated free fatty acids and cholesterol, but did not separate cholesterol from 1,2-diglyceride. A mobile phase consisting of hexane/isopropanol/acetic acid (100∶2∶0.02) effectively separated free fatty acid, cholesterol, 1,2-diglyceride and 1,3-diglyceride. Recoveries of oleic acid and cholesterol were 100% and 97%, respectively. Five phospholipid classes were separated using methylteriarybutylether/methanol/aqueous ammonium acetate (pH 8.6) (5∶8∶2) as the mobile phase. The recoveries of phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine, sphingomyelin and lysophosphatidylcholine were each greater than 96%.
TL;DR: The effect of exposure of Wyoming bentonite to glacial acetic acid has been studied by F.T.i.r., X.p.s, SEM and acidity measurements, in order to investigate the possibility of using such a non-aqueous technique as an alternative activation process.
Abstract: The effect of exposure of Wyoming bentonite to glacial acetic acid has been studied by F.t.i.r., X.p.s, SEM and acidity measurements, in order to investigate the possibility of using such a non-aqueous technique as an alternative activation process. Treatment with glacial acetic acid, results in an overall increase in the concentration of acid sites. However, the number of Bronsted sites is reduced, whereas the population of Lewis sites increases. This change is accompanied by the leaching out of Al3+, but with no extensive loss of crystallinity. Treatment with mineral acids results in an increase in Bronsted acidity.
TL;DR: The condensation method has been used at a variety of locations in the southwestern United States to determine the concentrations of formaldehyde, formic acid, and the group of organic acids coeluting with acetic acid as discussed by the authors.
Abstract: The condensation method has been used at a variety of locations in the southwestern United States to determine the concentrations of formaldehyde, formic acid, and the group of organic acids coeluting with acetic acid (hereafter called ''acetic acid''). Urban concentrations were typically as follows: formaldehyde, 1.4 ppb; formic acid, 3 ppb; and acetic acid, 4 ppb. In remote areas, formic and acetic acid concentrations were typically 0.9 ppb and 0.6 ppb, respectively. The data suggested that (1) in forested and probably desert regions, there is a substantial natural production of organics, particularly the acids, during summer, presumably by vegetation; (2) at least in the southwestern United States, in summer, there is a relatively weak coupling between the cycles of formaldehyde and formic acid; (3) near San Diego, organic acid lifetimes may be much shorter than previously expected, i.e., only several days; (4) at the lowest concentrations observed, partitioning of the organic acids into cloud water would give aqueous concentrations similar to those found in rain. copyright American Geophysical Union 1988
TL;DR: The kinetics ofP.
Abstract: The kinetics ofP acidipropionici (ATCC25562), a xylose-utilizing rumen microorganism, was studied to assess its use for propionic acid production from wood hydrolyzates Propionic acid has been shown to have a stronger inhibitory effect than acetic acid, with the undissociated acid form being responsible for the majority of the inhibitory effect Thus, in batch tests with pH controlled at 60, the propionic acid concentration reaches 25 g/L and the acetic acid 7 g/L Xylose uptake rate is dependent on the specific growth rate and glucose concentration An immobilized cell columnar reactor at very high product yields (80%) proved adequate for propionic production At cell concentrations of 95 g/L with high product concentration, volumetric productivities of 27 g/L·h were obtained in ultrafiltration cell recycle systems
TL;DR: In this article, the activation energy for the formation of methanol was estimated as 5.6 kcal mol−1, and the generalized reaction pathway was discussed, where the major product was methanoline (selectivity, ~70% at 90 °C), followed by formic acid (11%), ethanol (5%), formaldehyde (5), acetone (4%), and acetic acid (3%).
TL;DR: In this article, a thermogravimetric/mass spectrometric (TG/MS) system was used to characterize the thermolysis reactions of (4-O-methyl-D-glucurono)-D-xylan.
Abstract: A thermogravimetric/mass spectrometric (TG/MS) system was used to characterize the thermolysis reactions of (4-O-methyl-D-glucurono)-D-xylan. The mass spectrometric peaks, measured as function of time, were attributed to water, methanol, carbon monoxide, carbon dioxide, formaldehyde, formic acid, acetic acid, acetone, acrolein, 2-furaldehyde, and 3-hydroxy-2-penteno-1,5-lactone. The time derivative of the thermogravimetric curve (DTG) consisted of two partially overlapping peaks, indicating a multistep mechanism. The mass spectrometric intensities of the peaks assigned to methanol and 2-furaldehyde coincided with the first DTG peak, suggesting that the first DTG peak represents both dehydration and fragmentation pathways. Methanol, water, formyl group, and carbon dioxide contributed to both of the DTG peaks. This indicates that the dehydration, decarboxylation, and decarbonylation took place in two steps. The compounds observed only in the second DTG peak and later (acetone, formic acid, formaldehyde, acrolein, acetic acid, and 3-hydroxy-2-penteno-1,5-lactone) are probably products of reactions which occur after the collapse of the original polysaccharide structure.
TL;DR: The synthesis of indole-3-acetyl-1-O-beta-D-glucose from indole, 3,4-dichlorophenoxy-acetic acid and uridine diphosphoglucose has been shown to be a reversible reaction with the equilibrium away from ester formation and toward formation of IAA.
Abstract: The synthesis of indole-3-acetyl-1-O-beta-D-glucose from indole-3-acetic acid (IAA) and uridine diphosphoglucose (UDPG) has been shown to be a reversible reaction with the equilibrium away from ester formation and toward formation of IAA The enzyme occurs primarily in the liquid endosperm of the corn kernel but some activity occurs in the embryo It is relatively specific showing no glucose ester formation with oxindole-3-acetic acid or 7-hydroxy-oxindole-3-acetic acid, and low activity with phenylpropene acids, such as rho-coumaric acid The enzyme is also specific for the nucleotide sugar showing no activity with UDPGalactose or UDPXylose The enzyme is inhibited by inorganic pyrophosphate, by phosphate esters and by phospholipids, particularly phosphatidyl ethanolamine The enzyme is inhibited by zeatin, by 2,4-dichlorophenoxy-acetic acid, by IAA-myo-inositol and IAA-glucan, but not by zeatin riboside, and only weakly by gibberellic acid, abscisic acid and kinetin The reaction is slightly stimulated by both calcium and calmodulin and, in some cases, by thiol compounds The role of this enzyme in the homeostatic control of indole-3-acetic acid levels in Zea mays is discussed