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Biophysical Journal Oct 1979The permeation of acetic acid through large unilamellar phospholipid vesicle membranes has been investigated using the unique capability of nuclear magnetic resonance to...
The permeation of acetic acid through large unilamellar phospholipid vesicle membranes has been investigated using the unique capability of nuclear magnetic resonance to characterize flow under pseudo-equilibrium conditions. Two types of experiments have been employed: total line shape analysis and selective population transfer. These techniques are sensitive to permeation on time scales ranging form 0.001 to 10.0 s. The permeation rate dependence on pH and acetic acid concentration indicates that the neutral acetic acid monomer is the dominant permeant species with a permeation coefficient of 5 +/- 2 x 10-4 cm/s. Mechanisms of permeation and the applicability of nuclear magnetic resonance methodology are discussed.
Topics: Acetates; Acetic Acid; Liposomes; Magnetic Resonance Spectroscopy; Mathematics; Molecular Conformation; Phosphatidic Acids; Phosphatidylcholines; Thermodynamics
PubMed: 262441
DOI: 10.1016/S0006-3495(79)85154-1 -
Journal of Agricultural and Food... Jun 2010Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and...
Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and rapid method for discriminating the fermentation of the raw materials of vinegar by measuring the hydrogen and carbon isotope ratio of acetic acid using head space solid-phase microextraction (HS-SPME) combined with gas chromatography-high temperature conversion or combustion-isotope ratio mass spectrometry (GC-TC/C-IRMS). The measurement of acetic acid in vinegar by this method was possible with repeatabilities (1sigma) of +/-5.0 per thousand for hydrogen and +/-0.4 per thousand for carbon, which are sufficient to discriminate the origin of acetic acid. The fermentation of raw materials of several vinegars was evaluated by this method.
Topics: Acetic Acid; Carbon Isotopes; Deuterium; Gas Chromatography-Mass Spectrometry; Solid Phase Microextraction
PubMed: 20504023
DOI: 10.1021/jf100406y -
Nature May 1952
Topics: Acetates; Acetic Acid; Ascorbic Acid; Carbohydrate Metabolism; Fruit; Oxidation-Reduction; Vegetables
PubMed: 14941096
DOI: 10.1038/169934b0 -
Chemosphere Mar 2013We have developed a direct esterification of aqueous acetic acid with ethanol (molar ratio=1:1) catalyzed by polystyrene-supported or homogeneous sulfonic acids toward...
We have developed a direct esterification of aqueous acetic acid with ethanol (molar ratio=1:1) catalyzed by polystyrene-supported or homogeneous sulfonic acids toward the recovery of acetic acid from wastewater in chemical plants. The equilibrium yield was significantly increased by the addition of toluene, which had a high ability to extract ethyl acetate from the aqueous phase. It was shown that low-loading and alkylated polystyrene-supported sulfonic acid efficiently accelerated the reaction. These results suggest that the construction of hydrophobic reaction environments in water was critical in improving the chemical yield. Addition of inorganic salts was also effective for the reaction under not only biphasic conditions (toluene-water) but also toluene-free conditions, because the mutual solubility of ethyl acetate and water was suppressed by the salting-out effect. Among the tested salts, CaCl(2) was found to be the most suitable for this reaction system.
Topics: Acetic Acid; Catalysis; Esterification; Ethanol; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical
PubMed: 23290939
DOI: 10.1016/j.chemosphere.2012.11.078 -
The Analyst Dec 1949
Topics: Acetates; Acetic Acid; Acids; Amines; Ethylenediamines; Ethylenes; Humans; Polarography
PubMed: 15400353
DOI: 10.1039/an9497400629 -
Bioorganic Chemistry Aug 20152-Hydroxy-2-(ethoxyphenylphosphinyl)acetic acid, a new type of organophosphorus compound possessing two stereogenic centers, was investigated. Racemic...
2-Hydroxy-2-(ethoxyphenylphosphinyl)acetic acid, a new type of organophosphorus compound possessing two stereogenic centers, was investigated. Racemic 2-butyryloxy-2-(ethoxyphenylphosphinyl)acetic acid was synthesized and hydrolyzed using four bacterial species as biocatalysts. In all cases the reaction was more or less stereoselective and isomers bearing a phosphorus atom with an (SP)-configuration were hydrolyzed preferentially. The observed (1)H and (31)P NMR chemical shifts of Mosher esters of 2-hydroxy-2-(ethoxyphenylphosphinyl)acetic acid were correlated with the configurations of both stereogenic centers of all four stereoisomers.
Topics: Acetic Acid; Bacillus subtilis; Biotransformation; Escherichia coli; Esters; Magnetic Resonance Spectroscopy; Organophosphorus Compounds; Stereoisomerism
PubMed: 26069926
DOI: 10.1016/j.bioorg.2015.05.006 -
American Industrial Hygiene Association... Jun 1956
Topics: Acetates; Acetic Acid; Air Pollution
PubMed: 13326849
DOI: 10.1080/00968205609344398 -
The Journal of Chemical Physics Nov 2006Infrared (IR) vibrational spectroscopy of acetic acid (A) neutral and ionic monomers and clusters, employing vacuum ultraviolet (VUV), 10.5 eV single photon ionization...
Infrared (IR) vibrational spectroscopy of acetic acid (A) neutral and ionic monomers and clusters, employing vacuum ultraviolet (VUV), 10.5 eV single photon ionization of supersonically expanded and cooled acetic acid samples, is presented and discussed. Molecular and cluster species are identified by time of flight mass spectroscopy: the major mass features observed are A(n)H(+) (n=1-9), ACOOH(+) (VUV ionization) without IR radiation present, and A(+) with both IR and VUV radiation present. The intense feature ACOOH(+) arises from the cleavage of (A)(2) at the beta-CC bond to generate ACOOH(+)+CH(3) following ionization. The vibrational spectrum of monomeric acetic acid (2500-7500 cm(-1)) is measured by nonresonant ionization detected infrared (NRID-IR) spectroscopy. The fundamentals and overtones of the CH and OH stretches and some combination bands are identified in the spectrum. Mass selected IR spectra of neutral and cationic acetic acid clusters are measured in the 2500-3800 cm(-1) range employing nonresonant ionization dip-IR and IR photodissociation (IRPD) spectroscopies, respectively. Characteristic bands observed at approximately 2500-2900 cm(-1) for the cyclic ring dimer are identified and tentatively assigned. For large neutral acetic acid clusters A(n)(n>2), spectra display only hydrogen bonded OH stretch features, while the CH modes (2500-2900 cm(-1)) do not change with cluster size n. The IRPD spectra of protonated (cationic) acetic acid clusters A(n)H(+) (n=1-7) exhibit a blueshift of the free OH stretch with increasing n. These bands finally disappear for n> or =6, and one broad and weak band due to hydrogen bonded OH stretch vibrations at approximately 3350 cm(-1) is detected. These results indicate that at least one OH group is not involved in the hydrogen bonding network for the smaller (n< or =5) A(n)H(+) species. The disappearance of the free OH stretch feature at n> or =6 suggests that closed cyclic structures form for A(n)H(+) for the larger clusters (n> or =6).
Topics: Acetic Acid; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet
PubMed: 17115753
DOI: 10.1063/1.2378626 -
Ultrasonics Sonochemistry Feb 2007In this work, ultrasonic degradation of acetic acid, which is one of the most resistant carboxylic acids to oxidize, was investigated. The effects of parameters such as...
In this work, ultrasonic degradation of acetic acid, which is one of the most resistant carboxylic acids to oxidize, was investigated. The effects of parameters such as ultrasonic power, initial concentration, addition of NaCl or several oxides were studied on the degradation of acetic acid. Acetic acid was sonicated indirectly using an ultrasonic bath with 40 kHz. It was observed that degradation degree increased with decreasing power and initial concentration and with increasing NaCl concentration. Initial degradation degree was enhanced with addition of zeolite and SiO(2).
Topics: Acetic Acid; Sodium Chloride; Solutions; Sonication; Water
PubMed: 16750650
DOI: 10.1016/j.ultsonch.2006.03.009 -
Nature May 1957
Topics: Acetates; Acetic Acid; Aspergillus; Aspergillus niger; Spores, Fungal
PubMed: 13430740
DOI: 10.1038/179922a0