Showing papers on "Oxalic acid published in 1986"
TL;DR: The feasibility of electropolymerization of phenol(s) in oxalic acid solutions at different electrodes (Pt, graphite, Fe) was demonstrated by voltammetric experiments as discussed by the authors.
104 citations
100 citations
TL;DR: To test the first alternative, ultrafiltered uremic serum and measured supersaturation with two different methods previously used to study supersaturation in urine, and found that local oxalate production or accumulation causes regional supersaturation.
Abstract: Serum oxalate rises in uremia because of decreased renal clearance, and crystals of calcium oxalate occur in the tissues of uremic patients. Crystal formation suggests that either uremic serum is supersaturated with calcium oxalate, or local oxalate production or accumulation causes regional supersaturation. To test the first alternative, we ultrafiltered uremic serum and measured supersaturation with two different methods previously used to study supersaturation in urine. First, the relative saturation ratio (RSR), the ratio of the dissolved calcium oxalate complex to the thermodynamic calcium oxalate solubility product, was estimated for 11 uremic (before and after dialysis) and 4 normal serum samples using a computer program. Mean ultrafiltrate oxalate predialysis was 89 +/- 8 microM/liter (+/- SEM), 31 +/- 4 postdialysis, and 10 +/- 3 in normals. Mean RSR was 1.7 +/- 0.1 (predialysis), 0.7 +/- 0.1 (postdialysis), and 0.2 +/- 0.1 (normal), where values greater than 1 denote supersaturation, less than 1, undersaturation. Second, the concentration product ratio (CPR), the ratio of the measured calcium oxalate concentration product before to that after incubation of the sample with calcium oxalate monohydrate crystal, was measured in seven uremic and seven normal serum ultrafiltrates. Mean oxalate was 91 +/- 11 (uremic) and 8 +/- 3 (normal). Mean CPR was 1.4 +/- 0.2 (uremic) and 0.2 +/- 0.1 (normal). Predialysis, 17 of 18 uremic ultrafiltrates were supersaturated with respect to calcium oxalate. The degree of supersaturation was correlated with ultrafiltrate oxalate (RSR, r = 0.99, r = 29, P less than 0.001; CPR, r = 0.75, n = 11, P less than 0.001). A value of ultrafiltrate oxalate of 50 microM/liter separated undersaturated from supersaturated samples and occurred at a creatinine of approximately 9.0 mg/dl.
82 citations
TL;DR: Results suggested that both oxalates:OH and oxalate:Cl exchange occur on the brush border membrane of rabbit ileum, and it is found that an inside alkaline pH gradient stimulated [14C]oxalate uptake 10-fold at 1 min with a fourfold accumulation above equilibrated uptake at 5 min.
Abstract: This study demonstrates the presence of oxalate transporters on the brush border membrane of rabbit ileum. We found that an inside alkaline (pH = 8.5 inside, 6.5 outside) pH gradient stimulated [14C]oxalate uptake 10-fold at 1 min with a fourfold accumulation above equilibrated uptake at 5 min. 1 mM 4,4'-diisothiocyanostilbene-2,2'-disulfonate (disodium salt; DIDS) profoundly inhibited the pH-gradient stimulated oxalate uptake. Using an inwardly directed K+ gradient and valinomycin, we found no evidence for potential sensitive oxalate uptake. In contrast to Cl:HCO3 exchange, HCO3 did not stimulate oxalate uptake more than was seen with a pH gradient in the absence of HCO3. An outwardly directed Cl gradient (50 mM inside, 5 mM outside) stimulated oxalate uptake 10-fold at 1 min with a fivefold accumulation above equilibrated uptake. Cl-stimulated oxalate uptake was largely inhibited by DIDS. Addition of K+ and nigericin only slightly decreased the Cl gradient-stimulated oxalate uptake, which indicates that this stimulation was not primarily due to the Cl gradient generating an inside alkaline pH gradient via Cl:OH exchange. Further, an outwardly directed oxalate gradient stimulated 36Cl uptake. These results suggested that both oxalate:OH and oxalate:Cl exchange occur on the brush border membrane. To determine if one or both of these exchanges were on contaminating basolateral membrane, the vesicle preparation was further fractionated into a brush border and basolateral component using sucrose density gradient centrifugation. Both exchangers localized to the brush border component. A number of organic anions were examined (outwardly directed gradient) to determine if they could stimulate oxalate and Cl uptake. Only formate and oxaloacetate were found to stimulate oxalate and Cl uptake. An inwardly directed Na gradient only slightly stimulated oxalate uptake, which was inhibited by DIDS.
58 citations
TL;DR: Ammonia, nitric acid, sulfur dioxide and particles in two size ranges were collected at a rural site in northeastern U.S. in January-March 1984 as discussed by the authors, the concentrations of ammonium ranged between 0.0 and 0.5 ppbv, and sulfate in the fine particles were highly correlated, the regression line indicated that the most abundant compound was ammonium sulphate.
44 citations
TL;DR: The calcium oxalate crystallization rates in the 5-or 7-hour urines reveal a behavior parallel to that of the oxalic acid excretion profile, and new aspects of magnesium effects must be discussed.
36 citations
TL;DR: The major regularities of oxalic acid adsorption and electro-oxidation on a smooth platinum electrode have been investigated in this paper, and the results of the results have led to the conclusions regarding the mechanism of the electrooxidation process.
36 citations
Patent•
03 Dec 1986TL;DR: A solution for stabilizing red blood cells during storage contains, along with nutrients and other stabilizers, a safe and effective concentration of an inhibitor of a step of the glycolysis metabolic pathway which is subsequent to the step which forms 2,3-DPG.
Abstract: A solution for stabilizing red blood cells during storage contains, along with nutrients and other stabilizers, a safe and effective concentration of an inhibitor of a step of the glycolysis metabolic pathway which is subsequent to the step which forms 2,3-DPG. The inhibitor may be oxalic acid, sodium oxalate, potassium oxalate, or mixed salts thereof, for example.
34 citations
TL;DR: The molar enthalpies of solution extrapolated to infinite dilution are for anhydrous oxalic acid, Δ sol H m ∞ (298.15 K, m = 0.0200 mol · kg −1 ) = (18211 ± 69) J · mol −1, and for citric acid monohydrate, ǫ 0.
33 citations
TL;DR: In this paper, the sources of nitrous acid and nitric acid in air in the parts-per-billion concentration range are provided by means of room-temperature oxalic acid sublimation onto solid sodium nitrite and potassium nitrate, respectively.
Abstract: Sources of nitrous acid and nitric acid in air in the parts-per-billion concentration range are provided by means of room-temperature oxalic acid sublimation onto solid sodium nitrite and potassium nitrate, respectively. Nitrogen dioxide is not present and nitric oxide is present only at a small percentage in the nitrous acid source at relative humidities in the 30-60% range. The presence of nitrous acid is verified by spectroscopic and chemical reaction studies. Nitric oxide, hydrogen cyanide, and other compounds can be similarly produced with appropriate target compounds. Nitrogen dioxide from permeation devices must be used in plastic systems to minimize impurities.
31 citations
TL;DR: In this paper, a detailed characterization of synthetic humic substances (melanoidins synthesized from amino acids and glucose or galactose) by alkaline potassium permanganate oxidation has been conducted to deduce criteria upon which to test the melanoidin-derived structure of natural humic compounds.
TL;DR: In this paper, the conditions necessary for initial clay formation have been studied in different model systems comprising different organic acids besides Si and Al. The solid phases and the precipitation boundary characterizing the subsystem H+-Al3+-oxalic acid (H2L) are discussed.
01 Jan 1986
TL;DR: It is well known that during oxidation of oxalic acid esters by hydrogen peroxide, an intense chemiluminescence radiation is emitted as mentioned in this paper, and this phenomenon has been used already several times for the determination of HPC in different matrices down to very small concentrations.
Abstract: It is well known that during oxidation of oxalic acid esters by hydrogen peroxide an intense chemiluminescence radiation is emitted. This phenomenon has been used already several times for the determination of hydrogen peroxide in different matrices down to very small concentrations.
TL;DR: In this article, the synthesis of α-acylaminoalkyl 1.1-difluoro-3-butenyl ketones from α-amino acids was described.
Patent•
24 Nov 1986
TL;DR: In this paper, a collector emulsion mixture is added to the aqueous slurry of the comminuted rare earth metal compound containing oxidic mineral, which has been previously conditioned in a conventional manner.
Abstract: A process is described for the mineral separation of rare earth metal compounds, such as bastnaesite, contained in oxidic minerals. The process is a froth flotation process utilizing a novel collector emulsion, which is an emulsified mixture of: a secondary amine modified sulphonated fatty acid, a high rosin containing tall oil fatty acid, an anionic petroleum sulphonate, and a high molecular weight primary amine. The collector emulsion mixture is added to the aqueous slurry of the comminuted rare earth metal compound containing oxidic mineral, which has been previously conditioned in a conventional manner. The conditioning reagents may include alkaline pH modifiers and gangue depressants such as citric acid, oxalic acid, sodium silicates and fatty acids. The rare earth metal compounds will be concentrated in the froth, and are separated in the conventional manner.
TL;DR: Evidence is provided that oxalate is transported across the mitochondrial membrane by a phosphate-linked, carrier-mediated system similar to or identical to the dicarboxylate transporter.
TL;DR: A method is described for the determination of oxalate in urine using flow injection analysis and fluorimetry, which results are in good accordance with normal values found with traditional oxalates analysis.
TL;DR: In this paper, a method for the precipitation of plutonium(IV) oxalate from homogeneous solutions using diethyl oxalates is reported, and the precipitate obtained is crystalline and easily filterable with yields in the range of 92-98% for precipitations involving a few mg to g quantities of plutonium.
Abstract: A method for the precipitation of plutonium(IV) oxalate from homogeneous solutions using diethyl oxalate is reported. The precipitate obtained is crystalline and easily filterable with yields in the range of 92–98% for precipitations involving a few mg to g quantities of plutonium. Decontamination factors for common impurities such as U(VI), Am(III) and Fe(III) were determined. TGA and chemical analysis of the compound indicate its composition as Pu(C2O4)2·6H2O. Data are obtained on the solubility of the oxalate in nitric acid and in mixtures of nitric acid and oxalic acid of varying concentrations. Green PuO2 obtained by calcination of the oxalate has specifications within the recommended values for trace foreign substances such as chlorine, fluorine, carbon and nitrogen.
Patent•
18 Feb 1986
TL;DR: In this article, an iron complex ion-forming substance is added to an aqueous solution of an iron salt and neutralized with a neutralizing agent such as NaOH, NH 4 OH, etc., into a pH range stable against corrosion, ≥pH5 to give a combustion improver.
Abstract: PURPOSE: To contrive to suppress incombustible components in a boiler and to improve dust collection efficiency by an electric dust collector, by impregnating or blending a solid fuel with a combustion improver obtained by adding an iron complex ion-forming substance to an aqueous solution of an iron salt and then neutralizing the solution. CONSTITUTION: An iron complex ion-forming substance[e.g., citric acid, tartaric acid, sodium acetate, oxalic acid, triethanolamine, ethylenediaminetetraacetic acid (most preferably citric acid), etc.,] is added to an aqueous solution of iron salt and the solution is neutralized with a neutralizing agent such as NaOH, NH 4 OH, etc., into a pH range stable against corrosion, ≥pH5 to give a combustion improver. The combustion improver is impregnated into or blended with a solid fuel such as coal or coke, etc. COPYRIGHT: (C)1987,JPO&Japio
TL;DR: Arsenite is quantitatively and selectively extracted into carbon tetrachloride in the presence of arsenate, methylarsonic acid, and dimethylarsinic acid by 0.5% aqueous solutions of ammonium sec-butyldithiophosphate as mentioned in this paper.
Abstract: Arsenite is quantitatively and selectively extracted into carbon tetrachloride in the presence of arsenate, methylarsonic acid, and dimethylarsinic acid by 0.5% (w/v) aqueous solutions of ammonium sec-butyldithiophosphate. The organic extract is evaporated to dryness and the residue mineralized with conc. nitric acid. The arsenic in this solution (5% oxalic acid) is reduced by sodium borohydride to arsine. The arsine is passed into a DC helium arc and the arsenic emission monitored at 228.8 nm. The detection limit of the extraction/hydride generation system is 0.6 ng As per liter (expressed as the concentration that must be present in a 500 ml sample subject to extraction), approximately 150-times better than hydride generation without extraction. Arsenic compounds other than arsenite do not interfere. The extraction/hydride generation method was successfully used to determine arsenite in seawater and freshwater samples with As(arsenite) contents in the range 3 to 137 ng/l.
Patent•
29 Jan 1986
TL;DR: In this article, a mixture of a silicic ester, water, and an acid is used to enhance the purity of the titled quartz glass powder and facilitate the formation of a quartz crucible compact by preparing a gel from a mixed soln.
Abstract: PURPOSE:To enhance the purity of the titled quartz glass powder and to facilitate the formation of a quartz crucible compact by preparing a gel from a mixed soln. consisting of a silicic ester, water, and an acid, drying the gel, disintegrating the agglomerate of the obtained silica gel powder, and baking the powder. CONSTITUTION:A mixed soln. consisting of a silicic ester, >=1.5 equivalents water, based on the alkyl group in the silicic ester, and an acid is prepared. The hydrogen ion concn. in the mixed soln. is controlled to >=4.5 with aq. ammonia to gelate the soln., and then the gel is dried. The obtained agglomerate of silica gel powder is disintegrated into powder, and the powder is baked. When the agglomerate of silica gel powder is disintegrated, the agglomerate still staying hot is preferably charged into water and disintegrated. Hydrochloric acid, oxalic acid, etc., can be utilized as the acid.
TL;DR: In this article, the anodic formation of mercurous oxalate on mercury has been studied at pH⪢p K a1 of oxalic acid and voltammetric and transient results are described.
Journal Article•
Patent•
03 Apr 1986
TL;DR: In this paper, a positively charged antimony pentoxide sol sol is described, comprising colloidal particles of antimony polyoxide sol coated on their surfaces with at least one of trivalent and tetravalent metals.
Abstract: @ Disclosed is a positively charged antimony pentoxide sol, comprising colloidal particles of antimony pentoxide sol coated on their surfaces with at least one of trivalent and tetravalent metals, the content of the metals being 1 to 50% by weight in terms of the metal oxide based on antimony pentoxide in the antimony pentoxide sol. When the positively charged antimony pentoxide sol of this invention is mixed with a cationic resin emulsion or an (aqueous solution of a cationic water-soluble polymer, no agglomeration occurs and also, when it is added into an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, etc., or an organic acid such as acetic acid, propionic acid, oxalic acid, maleic acid, etc., an aqueous solution of a metal salt or amine salts of these acids or an organic solvent such as an alcohol, no agglomeration occurs but it is well dispersed therein, and therefore it can be applicable for fields in which the antimony pentoxide sole of the prior art cannot satisfactorily be used.
Patent•
28 Mar 1986
TL;DR: In this article, the authors present a method for successively bringing the surface of the contaminated materials into contact with a solution of sodium carbonate for some time, and then bringing the contaminated surfaces of these contaminated surfaces to contact with diluted nitric acid, while adding potassium permanganate, and finally rinsing and drying said materials.
Abstract: The process according to the present invention mainly consists in successively bringing the surface of the contaminated materials into contact with a solution of sodium carbonate for some time, bringing the surface of the contaminated materials into contact with a solution of diluted nitric acid, while potassium permanganate is being added, bringing the contaminated materials into contact with a solution of oxalic acid (COOH--COOH.2H 2 O), and finally rinsing and drying said materials.
TL;DR: The reaction of aqueous solutions of oxalic acid with ferric nitrate indicated formation of ferric oxalate complexes with a stoichiometry of Fe 2 (oxalate) 3 in solution, using Job's method of continuous variations (1925;1928).
Abstract: N-phenyglycine plays a very important role in obtaining adhesion of restorative composites to dentin and enamel (Bowen et al., 1982a). In a systematic investigation, ferric or ferrous N-phenylglycinate complexes formed when aqueous ferric nitrate or ferrous chloride was combined with solutions of potassium N-phenylglycinate in stoichiometric proportions. The molal ratios of iron ion to N-phenylglycinate ion in each complex were confirmed by osmolality measurements with a freezing-point osmometer. The reaction of aqueous solutions of oxalic acid with ferric nitrate indicated formation of ferric oxalate complexes with a stoichiometry of Fe2(oxalate)3 in solution, using Job's method of continuous variations (1925;1928).
01 Jan 1986
TL;DR: In this paper, the release of organic complexing agents from solidified simulated decontamination resin wastes was measured using the standard procedure ANS 16.1, ''Measurements of the leachability of Solidified Low-Level Radioactive Wastes''.
Abstract: Data are presented on the release of organic complexing agents from solidified simulated decontamination resin wastes. The organic acids included were: ethylenediaminetetraacetic acid, oxalic acid, citric acid, picolinic acid, and formic acid. Additionally, samples were tested which contained the decontamination reagent LND-101A and a simulated resin waste expected with the LOMI (low-oxidation-state-metal ion) reagent. Ion-exchange resins equilibrated with the reagents were solidified in cement and vinyl ester-styrene. The release of the organic acids was measured using the standard procedure ANS 16.1, ''Measurements of the Leachability of Solidified Low-Level Radioactive Wastes.'' The data suggest that the release of the acids may follow a diffusion mechanism. Data are also presented which indicate that immersion in water can affect the compressive strength of solidified simulated decontamination resin wastes. Analytical methods are described which can be used to measure organic acids in waste form leachates. Ion chromatography proved to be the most versatile of the methods examined.
TL;DR: In this article, a number of organic compounds of different classes of substances (isobarbituric acid, citraconic acid and o-chlorophenol) were ozonized while varying their initial concentrations (c = 10-3 to 10-5 mol/L) at pH 7.
Abstract: Organic compounds of the different classes of substances (isobarbituric acid, citraconic acid and o-chlorophenol) were ozonized while varying their initial concentrations (c = 10-3 to 10-5 mol/L) at pH 7. In the case of isobarbituric acid at 10-3 mol/L, formyloxaluric acid, oxaluric acid, and formic acid were identified. At an initial concentration of 10-3 mol/L, alloxanic acid and oxalic acid were formed in addition to oxaluric acid and formic acid. In both cases, the rates of elimination are similar.After ozonation of citraconic acid (c = 10-5 mol/L, pH 7), the following oxidation products were identified: glyoxylic, acetic, formic, oxalic, pyruvic, and hydroxypyruvic acids.
Patent•
21 Apr 1986
TL;DR: In this paper, a chemical cleaning agent suitable for decontamination of nuclear power apparatuses by adding hydrazine to malonic acid and oxalic acid was presented.
Abstract: PURPOSE: To produce a chemical cleaning agent suitable for the decontamination of nuclear power apparatuses by adding hydrazine to malonic acid and oxalic acid. CONSTITUTION: A composition contg. malonic acid, oxalic acid and hydrazine as effective components is prepd. At this time, malonic acid and oxalic acid are used in 9:1W1:9 weight ratio and the total concn. in the composition is regulated to 1W10wt%. The amount of hydrazine added is 500W5,000mg/l. The pH of the composition is adjusted to 2.5W6 with ammonium hydroxide or the like and cleaning with the composition is preferably carried out at about 80W100°C. The composition has high cleaning power, can decontaminate a radioactive clad, hardly corrodes metallic materials and ensures superior cleaning work efficiency at a job site. COPYRIGHT: (C)1987,JPO&Japio