Showing papers on "Acetic acid published in 1980"
TL;DR: The inability of reagents to prevent losses of soluble metal in these experiments strongly suggests that a proportion of the metal actually released from a sediment sample during an extraction will be readsorbed, which may lead to serious misinterpretation of extraction data.
Abstract: w The adsorption of Cu, Pb, and Cd from selected extractant solutions, onto uncontaminated river sediments, has been investigated under typical extraction conditions. Significant adsqrption of added metal was found to occur during overnight extraction with dilute HC1 (pH >1.5), 0.1 M hydroxylamine hydrochloride (pH 2), 0.1 M sodium citrate (pH 4.6), 1 M ammonium acetate, 10% sodium citrate-1% sodium dithionite, and 25% acetic acid. Adsorption also occurred during a hydrogen peroxide digestion procedure. The inability of reagents to prevent losses of soluble metal in these experiments strongly suggests that a proportion of the metal actually released from a sediment sample during an extraction will be readsorbed. This may lead to serious misinterpretation of extraction data because the metal concentrations determined in the extract do not represent metal levels in the sediment fractions attacked.
208 citations
01 Jan 1980
TL;DR: The two most important contributions to the elucidation of the fatty acid synthesis pathway was the discovery that acetyl-CoA is the “active” form of the C2 substrate (Lynen and Reichert, 1951; Lynen et al., 1951), and that malonyl- coA contributes all the carbons but two to the fatty acids molecule (Wakil, 1958).
Abstract: The realization that carbohydrates can be converted to fat prompted several theories on the formation of fatty acids. For example, Emil Fischer proposed the “hexose condensation theory” where three sugar molecules condense to form a C18 fatty acid after the hydroxyl groups have been reduced (Fischer, 1890). Later, it was proposed that acetaldehyde might serve as the initial substrate for fatty acid synthesis (Nencki, 1878). This was supported by the fact that the addition of acetaldehyde to the growth medium stimulates fatty acid production in several fungi (Haehn, 1921; Terroine and Bonnet, 1927; Ottke et al., 1951). Acetate was shown to be the C2 precursor of fatty acids when radiolabeled acetic acid resulted in greater amounts of labeled fatty acids than carbohydrates (Sonderhoff and Thomas, 1937). Probably the two most important contributions to the elucidation of the fatty acid synthesis pathway was the discovery that acetyl-CoA is the “active” form of the C2 substrate (Lynen and Reichert, 1951; Lynen et al., 1951), and that malonyl-CoA contributes all the carbons but two to the fatty acid molecule (Wakil, 1958; Wakil and Ganguly, 1959).
198 citations
TL;DR: In this paper, the rate and degree of extraction of anthocyanins from grape pomace depends upon a number of factors; this research concerned two: solvent (ethanol, methanol, water), and acid (HCl, citric, tartaric, formic, acetic, propionic).
Abstract: There is considerable interest in utilization of natural pigment as food colorants, particularly from raw materials in adequate supply, such as wine grape pomace. The rate and degree of extraction of anthocyanins from grape pomace depends upon a number of factors; this research concerned two: solvent (ethanol, methanol, water), and acid (HCl, citric, tartaric, formic, acetic, propionic). Methanol was the best extractant being 20% more effective than ethanol and 73% more effective than water. HCl was most effective with ethanol, but is also very corrosive. Of the organic acids, citric was most effective with methanol and acetic acid with water.
190 citations
TL;DR: Waste mycelia of Aspergillus niger from a citric acid production plant are simply treated with boiling 30–40% NaOH aqueous solutions for 4–6 hr to obtain the insoluble chitosan‐glucan complex whose infrared, ESR, and x‐ray diffraction spectra are reported.
Abstract: Waste mycelia of Aspergillus niger from a citric acid production plant are simply treated with boiling 30-40% NaOH aqueous solutions for 4-6 hr to obtain the insoluble chitosan-glucan complex whose infrared, ESR, and x-ray diffraction spectra are reported. A number of transition- and post-transition-metal ions are chelated and collected by chitosan-glucan with higher yields than by animal chitosan. Immediate flocculation occurs upon mixing chitosan-glucan dispersions with alginate and polymolybdate solutions. Membranes are also obtained from chitosan-glucan dispersions in acetic acid or in chloral and dimethyl formamide mixtures.
133 citations
Patent•
14 Apr 1980TL;DR: In this paper, a gas phase reaction is used to catalytically oxydehydrogenate to ethylene in the presence or absence of water, at temperatures of ≦550°C.
Abstract: Ethane is catalytically oxydehydrogenated to ethylene in a gas phase reaction, in the presence or absence of water, at temperatures of ≦550° C. using a catalyst comprising oxides of the elements Mo.sub.a X.sub.b Y.sub.c wherein X=Cr, Mn, Nb, Ta, Ti, V and/or W, Y=Bi, Ce, Co, Cu, Fe, K, Mg, Ni, P, Pb, Sb, Si, Sn, Tl and/or U, a=1, b=0 to 2, c=0 to 2, with the proviso that the total value of c for Co, Ni and and/or Fe is <0.5. Acetic acid is also produced.
101 citations
TL;DR: In this article, the use of other calcium salts (calcium chloride, calcium lactate, calcium acetate, calcane, calcium carbonate), and two noncalcium compounds (glucono-δ-lactone and acetic acid) was investigated.
Abstract: One of the delicate steps in the preparation of soybean curd is the addition of a salt to precipitate soy protein. The commonly employed salt is calcium sulfate. In this study, the use of other calcium salts (calcium chloride, calcium lactate, calcium acetate, calcium carbonate, calcium phosphate, calcium hydroxide, calcium gluconate) and two noncalcium compounds (glucono-δ-lactone and acetic acid) was investigated. The result showed that soy protein was precipitated by calcium chloride, calcium lactate, calcium acetate, calcium gluconate, glucono-δ-lactone, and acetic acid. The amount of chemical added to precipitate soy protein varied depending upon the type of compound used, but in all cases, soy protein was precipitated when the pH of soy milk was at or near 6.0. Calcium acetate and calcium chloride appeared to be good precipitants for soybean curd preparation. The quality and sensory score of the soybean curd prepared from these salts requires less skill than calcium sulfate because of solubility; besides, the amount of the salt needed to precipitate soy protein was less than one-half that of calcium sulfate.
77 citations
TL;DR: Analytical recovery of salicylic acid and metabolites from urine is complete and there was no significant interference in urine from patients being treated with various drugs other than aspirin.
Abstract: We have developed a specific and sensitive method for the determination of salicylic acid, salicyluric acid, and gentisic acid in urine. Any proteins present are precipitated with methyl cyanide. After centrifugation, an aliquot of the supernate is directly injected into an octadecyl silane reversed-phase chromatographic column, then eluted with a mixture of water, butanol, acetic acid, and sodium sulfate, and quantitated at 313 nm by ultraviolet detection according to peak-height ratios (with internal standard, o-methoxybenzoic acid) or peak heights (no internal standard). The method allows estimates within 25 min. Sensitivity was 0.2 mg/L for gentisic acid, and 0.5 mg/L for both salicyluric and salicylic acid (20-micro L injection volume); response was linear with concentration to at least 2.000 g/L for salicylic acid and metabolites. Analytical recovery of salicylic acid and metabolites from urine is complete. Intra-assay precision (coefficient of variation) is 5.52% at 7.5 mg/L for salicylic acid, 5.01% at 9.33 mg/L for salicyluric acid, and 3.07% at 7.96 mg/L for gentisic acid. Interassay precision is 7.32% at 7.51 mg/L for salicylic acid, 5.52% at 8.58 mg/L for salicyluric acid, and 3.97% at 8.32 mg/L for gentisic acid. We saw no significant interference in urine from patients being treated with various drugs other than aspirin.
73 citations
TL;DR: In this paper, β-keto esters and 1,3-diketones were oxidized regioselectively in aqueous acetic acid using Na2PdCl4 as the catalyst and t-butyl hydroperoxide or hydrogen peroxide as the reoxidant of Pd0.
Abstract: α,β-Unsaturated esters and ketones are oxidized regioselectively to give β-keto esters and 1,3-diketones in good yields in aqueous acetic acid using Na2PdCl4 as the catalyst and t-butyl hydroperoxide or hydrogen peroxide as the reoxidant of Pd0.
66 citations
TL;DR: In this paper, the infrared spectra of α-Fe 2 O 3 powders were measured in a study of surface structure and reactivity, and the experimental results give evidence that organic molecules put into contact with α-fe 2 o 3 activated in air or oxygen can generally be both physisorbed and chemisorbs on the surface.
65 citations
TL;DR: 3,4-dehydrochlorambucil is an intermediate in the β-oxidation of chlorambucIL by injecting an authentic sample into rats and observing the production of phenyl acetic acid mustard in the blood, allowing confirmation of structures proposed by g.l.c.-mass spectrometry.
55 citations
TL;DR: The presence of acetic acid seems to be a major cause of poor establishment and growth when seeds and seedling roots come into contact with straw.
Abstract: Freshly harvested wheat straw contained 0.096 g water g−1 dry straw and 180 mM acetic acid. The straw absorbed water more rapidly from wet soil. The concentration of acetic acid fell to about 10 mM within 6 h of incorporation of straw in the soil and then remained relatively constant for a period of 12 days, irrespective of soil moisture content. In soil at its maximum water holding capacity after gravitational drainage, the decline in acetic acid concentration (c) with distance (d) from wheat or barley straw was exponential, with c=co e−nd where co is the concentration of acetic acid at the straw surface and n is a constant (0.46 for barley and 0.42 for wheat straw). The presence of acetic acid seems to be a major cause of poor establishment and growth when seeds and seedling roots come into contact with straw.
Patent•
28 Apr 1980TL;DR: In this article, the improvement comprising a flasher or stripper to separate methyl acetate and water from the hydrolyzer product stream and the recycle of these directly to the Hydrolyzer is described.
Abstract: In the hydrolysis of methyl acetate to acetic acid, the improvement comprising a flasher or stripper to separate methyl acetate and water from the hydrolyzer product stream and the recycle of these directly to the hydrolyzer.
Journal Article•
TL;DR: It is concluded that the concentration of undissociated acetate influences sodium and water absorption in the colon of the pig and may have important consequences on the reserve absorptive capacity of the colon in certain diarrheal diseases.
Abstract: The effect of acetate, at physiologic concentrations, on sodium and water absorption in the temporarily isolated colon of the conscious pig was studied with isotonic perfusion solutions buffered at pH 6.4 or 7.4, in which either chloride or acetate was present as the major anion. Sodium and water absorption was greater from the acetate solution when the pH was low; however, acetate reduced sodium and water absorption below that observed with the chloride solution when the pH was high. There were no significant differences observed in sodium or water absorption from the chloride solution at either pH. We conclude that the concentration of undissociated acetate influences sodium and water absorption in the colon of the pig. Such an effect may have important consequences on the reserve absorptive capacity of the colon in certain diarrheal diseases.
TL;DR: In this article, the interaction of acetic acid and ethylenediamine with vapor deposited and oxygen precovered iron and nickel was investigated by means of X-ray photoelectron spectroscopy.
TL;DR: Pharmacokinetic parameters obtained by this method after a single oral dose of 900 mg soluble, effervescent acetylsalicylic acid in normal healthy subjects suggest that absorption, distribution, and elimination of acetylSalicylic Acid are rapidly occurring events.
Abstract: Plasma acetylsalicylic acid and salicylic acid are assayed by a specific, rapid, and sensitive high performance liquid chromatographic procedure. The plasma samples are treated with physostigmine to inhibit esterase activity that otherwise will promote enzymatic hydrolysis of acetylsalicylic acid to salicylic acid. Conditions are chosen such that the total in vitro hydrolysis of acetylsalicylic acid is minimized to less than 5%. Plasma samples are deproteinated with methylcyanide. Acetylsalicylic acid and salicylic acid are separated by elution with a mixture of methanol, acetic acid, and water on a reversed-phase octadecyl silane column and detected by ultraviolet absorption. Quantitation is achieved by measuring absolute peak heights. Recovery and repeatability studies are good. No interference was observed when 50 drugs were also present in the various plasma samples. Concentrations of acetylsalicylic acid and salicylic acid can be obtained within 20 min of receipt of the blood specimens. Pharmacokinetic parameters obtained by this method after a single oral dose of 900 mg soluble, effervescent acetylsalicylic acid in normal healthy subjects suggest that absorption, distribution, and elimination of acetylsalicylic acid are rapidly occurring events.
TL;DR: Generation of bromonitrile oxide in the presence of vinylglycine leads to the formation of the title compound 2 and its threo isomer in good yield as discussed by the authors.
TL;DR: It is shown that dipropyl disulfide, also known as ethyl acetate, tetramethylpyrazine, n-heptanal, and 2-pentanol have different phytochemical properties.
Abstract: タマネギバエ幼虫は摂食のため, また成虫は産卵のためタマネギに誘引される. しかし, 細菌で腐敗しかかったタマネギは, 新鮮なものよりはるかに誘引性が高い. そこで腐敗しかかったタマネギから誘引物質を産生している細菌 Klebsiella sp. を分離した. この細菌をタマネギ片に接種し37℃で3日間培養し, その嗅気をポラパックQカラムで捕集した. この嗅気物質を高速液体ガスクロマトグラフィーで分離し, 質量スペクトルにより化学構造式を同定した結果, 既知の誘引性硫黄化合物のほかに ethyl acetate, tetramethylpyrazine, n-heptanal, 2-pentanol などを含むことがわかった. これらの市販化合物を生物検定した結果, 幼虫に対して, ethyl acetate は単体で最もよく誘引し, tetramethylpyrazine, n-heptanal は混合することによって dipropyl disulfide の誘引性を数倍高めた. 一方, 成虫の産卵に対しては, ethyl acetate, tetramethylpyrazine が dipropyl disulfide の誘引性を数倍加した.
Journal Article•
TL;DR: Transport of the serotonin metabolite, 5-hydroxy-3-indole-acetic acid was more effectively inhibited by these pesticides than by the classical inhibitor, probenecid, neither the parent amine, serotonin, nor the uncharged pesticides.
Abstract: In this study, two questions were addressed: 1) were anionic pesticides accumulated by choroid plexus via the organic acid transport system and 2) did such accumulation impair transport of anionic neurotransmitter metabolites normally eliminated from brain via this system? Rabbit lateral choroid plexi were incubated in Krebs-Ringer bicarbonate buffer in vitro with the herbicide, 2,4-dichlorophenoxyacetic acid, or the polar DDT metabolite, 2,2-bis (p-chlorophenyl)acetic acid (DDA). Both compounds were extensively accumulated. At a pesticide concentration of 1 microM, tissue-to-medium ratios of 40 (DDA) to 50 (2,4-dichlorophenoxyacetic acid) were found after 60-min incubation at 37 degrees C. Uptake of both compounds was energy- and concentration-dependent and could be inhibited by other organic anions. 2,4-Dichlorophenoxyacetic acid and DDA each produced dose-dependent inhibition of the uptake of the other pesticide. DDA was the more potent inhibitor. Thus, uptake of both compounds appeared to be mediated by the organic acid transport system. Furthermore, transport of the serotonin metabolite, 5-hydroxy-3-indole-acetic acid was more effectively inhibited by these pesticides than by the classical inhibitor, probenecid. Neither the parent amine, serotonin, nor the uncharged pesticides. DDT and dieldrin, inhibited 5-hydroxy-3-indole-acetic acid uptake. Thus, the effect appears specific for those compounds which share the organic anion transport system.
TL;DR: Addition of ascorbic acid to the sanitizer to reduce oxidation of the meat pigments resulted in lowered microbial counts and the effect of pH on microbial destruction at the concentration of acid used, however, more microorganisms were killed as time of exposure to the acid was increased.
TL;DR: In this article, a strain of Acetobacterium species producing extracellular polysaccharide aggregated in the presence of hydrous titanium(IV) oxide thereby enabling higher medium flow rates and an increased acetic acid output to be achieved.
TL;DR: Dodecyl acetate appears to function as a short-range pheromone component in Trichoplusia ni and increases significantly the time they spent searching for the source when within 50 cm, as compared to (Z)-7-dodecenyl acetates alone.
Abstract: Dodecyl acetate was identified as a second component of the sex pheromone ofTrichoplusia ni (Hubner) Dodecyl acetate comprised 96% by weight of the total pheromone [(Z)-7-dodecenyl acetate plus dodecyl acetate] extracted from glands and 73% by weight of the total pheromone evaporated from the surfaces of glands Dodecyl acetate appears to function as a short-range pheromone component Evaporation at female release rates of a 10∶90 mixture of dodecyl acetate and (Z)-7-dodecenyl acetate in the field caused a significantly greater percentage of males to land on the pheromone source, increased significantly the time they spent on the source, but decreased significantly the time they spent searching for the source when within 50 cm, as compared to (Z)-7-dodecenyl acetate alone
TL;DR: Long-term continuous culture tests showed that 0–6 mM or more sulphate increased the maximum growth rate of the culture from 0–07–0–08 d without sulphate to 0–14-0–16/d, even at iron levels of 0–02–0-05 mM.
Abstract: Sulphate stimulated the rate of conversion of acetic acid to methane in enriched cultures as well as in liquid from anaerobic fermenters fed with wastes, but the effect depended on the soluble iron content of the culture. At low soluble iron contents, i.e. 0–02–0–05 mM, sulphate had little or no immediate (after 7–10 d) effect, but at 0–5 mM or higher soluble iron content, sulphate (0–6 mM or more) significantly increased the rate of acetic acid conversion over that obtained with 0–5 mM soluble iron without sulphate. Long-term continuous culture tests (100–160 d) showed that 0–6 mM or more sulphate increased the maximum growth rate of the culture from 0–07–0–08 d without sulphate to 0–14–0–16/d, even at iron levels of 0–02–0–05 mM. Hydrogen was inhibitory to the conversion of acetic acid to methane under all conditions tested, but stimulated the reduction of sulphate when present.
TL;DR: In this article, the authors used 1,100 strains of acetic acid bacteria from vinegar mash, soils in vinegar factories and fruits, and their activities to oxidize ethanol at high temperature were examined.
Abstract: Industrial vinegar production by submerged acetic acid fermentation has been carried out using Acetobacter strains at about 30°C. To obtain strains suitable for acetic acid fermentation at higher temperature, about 1,100 strains of acetic acid bacteria were isolated from vinegar mash, soils in vinegar factories and fruits, and their activities to oxidize ethanol at high temperature were examined. One of these strains, No. 1023, identified as Acetobacter aceti, retained full activity to produce acetic acid in continuous submerged culture at 35°C and produced 45% of activity at 38°C, while the usual strain of A. aceti completely lost its activity at 35°C. Thus the use of this strain may reduce the cooling costs of industrial vinegar production.
Patent•
20 Jun 1980TL;DR: In this article, a substituted aromatic compound e.g. p-xylene is oxidized to an aromatic dicarboxylic acid using a Co/Mn/Br catalyst in acetic acid.
Abstract: A substituted aromatic compound e.g. p-xylene is oxidized to an aromatic dicarboxylic acid e.g. terephthalic acid using a Co/Mn/Br catalyst in acetic acid and the slurry product is purified by treating with molecular oxygen and diluting with fresh acetic acid before separation of the terephthalic acid and mother liquor.
TL;DR: In this article, an analytical method for chitin determination in biological materials was developed based on determination of the acetic acid liberated by acid or alkaline hydrolysis of chitins.
Journal Article•
TL;DR: Denitrification was found to be the most efficient in medium with ethanol or acetic acid, and the presence of glucose facilitated the selection of Alcaligenes faecalis whereas the other carbon sources enabled theselection of bacteria of the genus Pseudomonas.
Abstract: The effect of methanol, ethanol, acetic acid and glucose together with NaNO2 or KNO3 (1,000 mg N/l) on the intensity of denitrification and selection of denitrifying bacteria from the bottom sludge of nitrogenous wastewater reservoir was examined. Denitrification was found to be the most efficient in medium with ethanol or acetic acid. The presence of glucose facilitated the selection of Alcaligenes faecalis whereas the other carbon sources enabled the selection of bacteria of the genus Pseudomonas: methanol -- P. fluorescens, ethanol -- P. mendocina. In medium with acetic acid species selection depends on the form of nitrogen: NaNO2 -- P. fluorescens, KNO3 -- P. aeruginosa.
TL;DR: Compounds A and B were identified as dioxindole-3-acetic acid derivatives by the UV spectra and their yielding 2-quinolone-4-carboxylic acid upon hydrolysis indicated that compound A is not a detoxication product induced by an abnormally high concentration of IAA.
Abstract: Three indole-3-acetic acid (IAA) metabolites [compounds A and B and indole-3-acetylaspartic acid (IAAsp) ] accumulated in Vicia faba roots when (14)C-IAA was applied to the cotyledon. IAAsp formation was increased by the application of a high concentration (2.5 × 10(-4) m) of IAA, while the accumulation of compound A was more conspicuous in the roots when a lower concentration (3.3 × 10(-5) m) of IAA had been applied. This indicates that compound A is not a detoxication product induced by an abnormally high concentration of IAA. Compounds A and B were identified as dioxindole-3-acetic acid derivatives by the UV spectra and their yielding 2-quinolone-4-carboxylic acid upon hydrolysis. Compound A was found to exist in Vicia roots not treated with exogenous IAA, and its naturally occurring content was estimated to be 1 μmole kg(-1) fresh weight. The amount of native compound B was far less than that of compound A.
TL;DR: In this article, the reaction of 3-oxo-1,2-benzoisothiazoline-2-acetamide 1,1-dioxides (1a-f) with alkaline alkoxides was carried out under various conditions.
TL;DR: In this article, the authors investigated the kinetics of the catalytic oxidation of ethylene into acetic acid over Pd-V 2 O 5, and the influence of reactant partial pressures on the initial catalytic reaction rates and on the final composition of the catalyst was established.