Showing papers on "Oxalic acid published in 1980"
TL;DR: A novel spectrophotometric enzymic procedure for estimating oxalic acid in urine is described, which is rapid, sensitive, linear, and precise and agreed well with those obtained with a widely used chemical technique.
Abstract: A novel spectrophotometric enzymic procedure for estimating oxalic acid in urine is described. Oxalate oxidase, prepared from moss species, converts oxalic acid to hydrogen peroxide and carbon dioxide. Hydrogen peroxide is determined enzymatically with horseradish peroxidase, by oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone with N,N-dimethylaniline; the resulting indamine due is determined spectrophotometrically at 595 nm. Interfering substances are removed by adsorption to ion-exchange resins and oxidation with charcoal, thus avoiding oxalate recovery problems accompanying oxalate isolation. The procedure is rapid, sensitive, linear, and precise. Results agreed well with those obtained with a widely used chemical technique.
111 citations
TL;DR: Spinach, rhubarb, peanuts, chocolates, parsley and tea were found to contain high levels of oxalate, but beetroot was found to be five times as high as previously reported, but coca-cola and beer were almost free from oxalates.
Abstract: A specific enzymatic method was used to determine the oxalate content of some common foods. No preliminary isolation of oxalate was required and recoveries ranging from 95-110 per cent were obtained. Spinach, rhubarb, peanuts, chocolates, parsley and tea were found to contain high levels of oxalate as previously described by others. On the other hand the oxalate content of beetroot was found to be five times as high as previously reported, but coca-cola and beer were almost free from oxalate. Cereals and meat were either low or deficient in oxalate.
65 citations
Patent•
04 Feb 1980TL;DR: In this article, a composition comprised of a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, alkylene polyamine polyacetic acids and mixtures of such Chelating agents having a pH in the range of from about 8 to about 10 is brought into contact with the deposits for a period of time sufficient for the deposits to be dissolved therein.
Abstract: Methods and compositions for removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution. A composition comprised of a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, alkylene polyamine polyacetic acids and mixtures of such chelating agents having a pH in the range of from about 8 to about 10 is brought into contact with the deposits for a period of time sufficient for the deposits to be dissolved therein.
51 citations
TL;DR: In this article, a possible process for the electrolytic reduction of oxalic acid to glyoxylic acid was examined in filter press type cells varying from small bench scale to pilot plant size and it was shown that the product can be produced with current efficiencies better than 70% and chemical yields better than 90%.
Abstract: The work examines a possible process for the electrolytic reduction of oxalic acid to glyoxylic acid. The reaction is investigated in filter press type cells varying from small bench scale to pilot plant size and it is shown that the product can be produced with current efficiencies better than 70% and chemical yields better than 90%. It is demonstrated that the cell product containing 8–10 wt% of glyoxylic acid can be concentrated to the commercial specification of a 50 wt% aqueous solution.
45 citations
TL;DR: A two-enzyme method is presented for estimating urinary oxalate by continuous-flow analysis and it is shown that the normal range obtained by this method was 0.20 to 0.52 mmol/24h (18 to 47 mg/ 24h) with a mean value of 0.37 mmol/ 24 h (33 mg/24H).
Abstract: A two-enzyme method is presented for estimating urinary oxalate by continuous-flow analysis. Oxalate is decarboxylated, yielding formate, which is subsequently oxidized in the presence of NAD+, yielding NADH. The NADH, measured colorimetrically, is proportional to the amount of oxalate originally present in the sample. Urine is pretreated by precipitation of the oxalate and extraction of the precipitate in citrate buffer. A correction factor for the extraction efficiency is given by the recovery of [U-14C]oxalic acid added to aliquots of the 24-h urine specimen. The normal range obtained by this method was 0.20 to 0.52 mmol/24h (18 to 47 mg/24h) with a mean value of 0.37 mmol/24 h (33 mg/24h). The between-assay CV was 7.6% (n = 12), within-assay CV 3.2% (N = 25). Unlabeled oxalate (0.5 and 1.0 mol/L) added to 28 urine samples gave a mean analytical recovery of 95% (SD 10%).
43 citations
TL;DR: A gas-chromatographic procedure for the analysis of oxalic acid requires relatively small quantities of urine (1 ml) or plasma (5 ml) and the lower limit of detection is 20 nmol.
39 citations
TL;DR: Analytical recovery of [14C]oxalic acid added to urine specimens ranged from 15 to 95% (mean, 80%), and corrected recovery, based on calculation isotope-dilution techniques, ranged from 98 to 100%.
Abstract: We describe a simple, rapid method for determining urinary oxalate: isolation by precipitation with calcium chloride and conversion to dimethyl oxalate, which then is measured by gas chromatography. To each sample, tracer amounts of 14C-labeled oxalic acid are added, to determine the analytical recovery of urinary oxalate. Analytical recovery of [14C]oxalic acid added to urine specimens ranged from 15 to 95% (mean, 80%), and corrected recovery, based on calculation isotope-dilution techniques, ranged from 98 to 100%. The urinary excretion of oxalic acid by 18 normal men, ages 23 to 43 years, ranged between 9 and 23 mg/24h, with a mean value of 16 mg; that by 68 patients with small-bowel bypass ranged from 60 to 210 mg/24 h, with a mean of 127 mg.
30 citations
TL;DR: Spinach chloroplast phenolase was inhibited by oxalic acid and its salts and a pure mushroom tyrosinase (phenolase) was obtained using the same conditions.
28 citations
TL;DR: A new colorimetric, enzymic method, based on a specific reaction of oxalate with oxidase is rapid, simple and precise for determination of serum oxalates from barley seedlings, showing a good correlation with a chemical method.
24 citations
TL;DR: It is concluded that these high concentrations of oxalate and calcium in the renal papilla are related to the formation of Randall's plaques and may be an essential factor in the pathogenesis of renal stones which is still far from clear.
Abstract: The renal papilla in man has been shown to contain a high concentration of oxalate (5 . 5 +/- 0 . 8 mmole/kg wet weight, mean +/- SEM, n = 7 kidneys), and that there is a significant concentration gradient between oxalate in the papilla and that of the medulla (0 . 4 +/- 0 . 08, P < 0 . 05) and the cortex (0 . 3 +/- 0 . 06, P < 0 . 05). Significant calcium and sodium gradients between renal papilla and medulla and cortex were confirmed and parallel that of oxalate. Potassium showed a significant decrease in the papilla (33 . 1 +/- 0 . 9) as compared to the medulla (42 . 1 +/- 1 . 9 P < 0 . 05). The concentrations of oxalate and calcium in the papilla were respectively 25-fold and 6-fold higher than the urinary concentration of oxalate and calcium. It is concluded that these high concentrations of oxalate and calcium in the renal papilla are related to the formation of Randall's plaques and may be an essential factor in the pathogenesis of renal stones which is still far from clear.
22 citations
TL;DR: The availability to rats of iron from two varieties of spinach was determined and the absorption of Fe was compared between FeCl3 and Fe-oxalate and the effects of adding 0.75% oxalate to the diet were determined.
Abstract: The availability to rats of iron from two varieties of spinach was determined. Also, the absorption of Fe was compared between FeCl3 and Fe-oxalate and the effects of adding 0.75% oxalate to the diet were determined. Absorption of iron from both varieties of spinach was comparable to that from FeCl3 and the iron was equally available from Fe-oxalate and FeCl3. The addition of 0.75% oxalic acid to the diet did not depress iron absorption and, if anything, appeared to enhance iron utilization by rats.
TL;DR: The ozone consumption was 3.2 mmol of O3 mmol−1 of acid until complete elimination of trans-trans muconic acid in aqueous solution (pH 3) as discussed by the authors.
TL;DR: In this paper, the influence of catechol, gallic acid and tiron on the voltammetric behavior of tin(IV) in the presence of lead(II) and cadmium(II), was investigated at hanging drop and mercury film electrodes in perchloric acid, oxalic acid or formate supporting electrolytes.
TL;DR: In this paper, the reaction of ozone with p-toluenesulfonic acid (PTA) at initial pH 3 and 12 in aqueous solutions (25°C) has been studied at initial concentration 1 mmol l−1 and ozone dose is 24 mg min−1 1.
TL;DR: Mixed-ligand complexes formed by copper(II) with an amino-acid and oxalic acid have been investigated polarographically and stability constants computed from the shift in half-wave potential with changing ligand are discussed.
Patent•
03 Oct 1980
TL;DR: In this article, a process for the preparation of PVP-iodine by reacting polyvinylpyrrolidone powder with elementary iodine at from 70° to 100° C is described.
Abstract: A process for the preparation of PVP-iodine by reacting polyvinylpyrrolidone powder with elementary iodine at from 70° to 100° C. The reaction is carried out in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid, formic acid or oxalic acid. The process avoids the disadvantage of long periods of heating, which can result in degradation of the polyvinylpyrrolidone, and is particularly suitable for the preparation of a stable PVP-iodine using a low molecular weight polyvinylpyrrolidone.
TL;DR: A convenient method is described for the accurate determination of small amounts of oxalate (at least as low as 0.02 μmol g−1 dry weight) in a number of plant tissues.
Abstract: A convenient method is described for the accurate determination of small amounts of oxalate (at least as low as 0.02 μmol g−1 dry weight) in a number of plant tissues. Crude, acidic extracts of plant tissues are analysed without purification. The carbon dioxide evolved from the quantitative decarboxylation of oxalate by the enzyme oxalate decarboxylase is measured by gas chromatography. The enzyme was prepared from Collybia velutipes.
TL;DR: In this article, the enamines derived from cyclohexanone or cyclopentanone are reacted with electrophilic olefins (ethyl acrylate, ethyl 2-methylacrylate and ethyl2-butenoate) to give the new enamines.
Patent•
21 Feb 1980
TL;DR: In this paper, a needle-like tin oxalate is formed by reacting a tin compound such as stannous chloride or stanous sulfate with oxalic acid, or its compound, such as sodium oxide, in a soln. contg.
Abstract: PURPOSE: To obtain needlelike tin oxide with superior electrical conductivity, whiteness, tansparency, etc. suitable for use as a material for the electrically conductive layer of an electrostatic recording body or the like by decomposing needlelike tin oxalate by heating in a specified temp. range. CONSTITUTION: Needlelike tin oxalate is formed by reacting a tin compound such as stannous chloride or stannous sulfate with oxalic acid or its compound such as sodium oxalate in a soln. contg. an about 0.01W10wt% surfactant such as glycerol ester of higher fatty acid or sucrose ester of higher fatty acid with 7W20 hydrophilic- lipophilic balance (HLB). The tin oxalate is calcined at 300W1,000°C to obtain the desired needlelike tin oxide having ≤10μm diameter and ≥5 needle ratio. This electrically conductive tin oxide is mixed into rubber, plastics or the like to make it electrically conductive. COPYRIGHT: (C)1981,JPO&Japio
TL;DR: In this paper, the corrosion behavior of steel in stagnant de-aerated citric and oxalic acid solutions (10−5-10−1M) in the pH range 2-6 was studied.
Patent•
19 Sep 1980
TL;DR: A process for the preparation of PVP-iodine having an iodine:iodide ratio of about 2:1 and a partition coefficient of 180-250, by reacting PVP with elementary iodine in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid as mentioned in this paper.
Abstract: A process for the preparation of PVP-iodine having an iodine:iodide ratio of about 2:1 and a partition coefficient of 180-250, by reacting PVP with elementary iodine in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid, formic acid or oxalic acid, in aqueous solution.
TL;DR: Analysis of changes in the pH-stat titrigram, the carbonate to aluminum ratio, the aluminum content of the supernate following centrifugation, and the adsorption of the organic solute indicates that polybasic acids may partially neutralize the aluminum hydroxycarbonate gel by a general acid effect.
TL;DR: In this paper, the graft copolymerization of methyl methacrylate onto silk fibers was investigated in aqueous solution using the Mn(IV)-oxalic acid redox system.
Abstract: The graft copolymerization of methyl methacrylate onto silk fibers was investigated in aqueous solution using the Mn(IV)–oxalic acid redox system. The copolymerization reaction was carried out under a variety of conditions such as different monomer, initiator, oxalic acid, acid concentrations, and temperatures. The graft yield increases with increasing initiator concentration up to 5 × 10−2M, and with further increase of the initiator concentration it decreases. The graft yield also increases with increasing sulfuric acid concentration up to 15 × 10−2M, and decreases thereafter. The rate of grafting also increases with increase in oxalic acid concentration up to 1.5 × 10−2M and 84.592 × 10−2M, respectively, and thereafter the rate of grafting shows down. The effect of temperature, solvents, and salts on graft yield has also been investigated and a plausible rate expression has been derived.
Patent•
29 Aug 1980
TL;DR: In this article, the authors presented a method to obtain the titled compound continuously useful as a raw material for synthesizing oxalic acid, etc., by subjecting the reaction product of CO and an ester of nitrous acid to separating process through condensation, reprocessing process of noncondensing gas, distillation process of a condensate, and hydrolyzing process of by-product.
Abstract: PURPOSE: To obtain the titled compound continuously useful as a raw material for synthesizing oxalic acid, etc., by subjecting the reaction product of CO and an ester of nitrous acid to separating process through condensation, reprocessing process of a noncondensing gas, distillation process of a condensate, and hydrolyzing process of by-product. CONSTITUTION: A gas comprising CO, an ester of nitrous acid, etc. is sent through the pipe 21 to the reactor 1 filled with a catalyst and reacted. The reaction product gas is sent to the condenser 2 and cooled, the condensate is sent through the pipe 14 to the distillation column 4. A noncondensing gas is sent through the pipe 12 to the reprocessing column 3, and the gas is brought into contact with a molecular oxygen- containing gas and an alcohol so that NO in the gas is processed to reproduce the ester of nitrous acid, which is sent through the pipes 19 and 21 to the reaction process. A carbonic acid diester, etc. is distilled by the distillation column 4, and an oxalic acid diester is taken out from the pipe 22. The distillate is sent through the pipes 23W25 to the hydrolyzing column 5 and hydrolyzed to give an alcohol, which is sent through the pipes 26, 28, and 18 to the reprocessing column 3. COPYRIGHT: (C)1982,JPO&Japio
Patent•
10 Mar 1980
TL;DR: In this paper, a mixture of an alkoxysilane, an organic carboxylic acid, and an alcohol was used to obtain a title coating liquid capable of affording smooth and uniform films free from any pinhole.
Abstract: PURPOSE:To obtain the title coating liquid capable of affording smooth and uniform films free from any pinhole, highly resistant to wear and chemicals, by reaction of a mixture of an alkoxysilane, an organic carboxylic acid, and an alcohol, in the presence of a specific accelerator CONSTITUTION:A mixture consisting of (A) 1 mole of an alkoxysilane, (B) 2-5 moles of an organic carboxylic acid such as glacial acetic acid, oxalic acid, etc, and (C) 2-10 moles of an alcohol such as methyl alcohol, ethyl alcohol, etc, is incorporated with (D) 0001-10wt%, based on the component (A), of a halogen- free in organic acid (a reaction accelerator) such as sulfric, nitric, phosphoric acid, etc The resulting system is made to react to a stage where the contents of the components (A) and (B) have reduced to 20wt% or less, based on their original amounts, respectively An organic solvent is subsequently added to the reaction mixture obtained to adjust so that a concentration calcurated in terms of silica in the system falls in 1-20wt%, followed by filtration through a 01-10mu-sized filter, thus obtaining the objective coating liquid
TL;DR: In this paper, the results of analysis of organic acid content of satsuma mandarin (Citrus unshiu Marc) after 140 days cold and controlled atmosphere (C. A.) storages were studied.
Abstract: Changes in fruit quality and some components, especially organic acid content, in satsuma mandarin (Citrus unshiu Marc.) after 140 days cold and controlled atmosphere (C. A.) storages were studied. Analysis of organic acid content was performed using silicic acid column chromatography. The results are summarized as follows 1. Under low humidity condition, some fruits became dry and browned. Under high carbon dioxide conditions, physiological disorders which indicated carbon dioxide injury were clearly observed. Pitting was found in some fruits stored at low temperature and 10-10 (C. A.) conditions. 2. Under high carbon dioxide conditions, the percentage of peel, `kahi-budomari' and the ratio of `rind puffing' were larger than under other conditions. The free acid in the flesh was also a little larger than under other conditions, and under low humidity and high carbon dioxide conditions, total acid and total sugar in the peel were a little larger than under other conditions. 3. In the flesh of the fruits, citric acid composed about 90% of the organic acid content ; malic acid was the second most abundant acid. During storage, formic acid and r-ketoglutaric acid fractions increased, while oxalic acid and malic acid decreased. Even under high carbon dioxide conditions, no distinct difference in organic acid composition was found. In the peel of the fruits, malic acid composed about 50% of the organic acid content ; citric acid was the second most abundant acid. During storage, formic acid increased and oxalic acid decreased. Under high carbon dioxide conditions, and also when 'stem-end rot' occurred, the malic acid decreased markedly, and the citric acid increased markedly.
TL;DR: Addition of 1 mM L-threonine to the growth medium of Fomes annosus inhibited its glyoxylate deliydrogenase activity and the synthesis of oxalic acid and Malate synthetase was synthesized de novo in the presence of L-thyrene.
Abstract: Addition of 1 mM L-threonine to the growth medium of Fomes annosus inhibited its glyoxylate deliydrogenase activity and the synthesis of oxalic acid. Malate synthetase was synthesized de novo in the presence of L-threonine. Lignosulfonate completely blocked the effect of the amino acid in both glucose or cellobiose-containing medium.
TL;DR: In this paper, the separation of trivalent actinides and rare earths from other fission products in high-level nuclear wastes by oxalate precipitation followed by ion exchange (OPIX) was experimentally investigated using synthetic wastes and a small-scale, continuous-flow oxalic acid precipitation and solid-liquid separation system.
Abstract: The separation of trivalent actinides and rare earths from other fission products in high-level nuclear wastes by oxalate precipitation followed by ion exchange (OPIX) was experimentally investigated using synthetic wastes and a small-scale, continuous-flow oxalic acid precipitation and solid-liquid separation system. Trivalent actinide and rare earth oxalates are relatively insoluble in 0.5 to 1.0 M HNO/sub 3/ whereas other fission product oxalates are not. The continuous-flow system consisted of one or two stirred-tank reactors in series for crystal growth. Oxalic acid and waste solutions were mixed in the first tank, with the product solid-liquid slurry leaving the second tank. Solid-liquid separation was tested by filters and by a gravity settler. The experiments determined the fraction of rare earths precipitated and separated from synthetic waste streams as a function of number of reactors, system temperature, oxalic acid concentration, liquid residence time in the process, power input to the stirred-tank reactors, and method of solid-liquid separation. The crystalline precipitate was characterized with respect to form, size, and chemical composition. These experiments are only the first step in converting a proposed chemical flowsheet into a process flowsheet suitable for large-scale remote operations at high activity levels.
Patent•
21 Jun 1980
TL;DR: In this article, a dissolving and removing composition of 3.0W 4.5pH for metallic oxide having high solvent power to metallic oxide of clad and very low corrosiveness was provided by adding hydrazine oxalate.
Abstract: PURPOSE: To provide a dissolving and removing composition of 3.0W4.5pH for metallic oxide having high solvent power to metallic oxide of clad, etc. and very low corrosiveness and causing no repollution due to reprecipitation or other phenomenon by adding hydrazine oxalate. CONSTITUTION: Said composition contains hydrazine oxalate, further contains hydroxycarboxylic acid such as citric acid as acid besides oxalic acid and has 3.0W 4.5pH. When citric acid is blended, the amount of citric acid to oxalic acid is adjusted to ≤50wt%. Since hydrazine oxalate in the composition has low solubility, it is desirable to prepare the composition while heating the oxalate to ≥ about 60°C immediately before application. When the composition is used as a detergent, it is introduced into the piping system of an objective apparatus to wash the apparatus and the piping at the same time. COPYRIGHT: (C)1982,JPO&Japio
TL;DR: In this article, the chemical shift tenson for the water molecule in α-oxalic acid dihydrate was measured using a multiple pulse, NMR technique, and high resolution proton speclia were recorded at room temperature.
Abstract: The chemical shift tenson for the water molecule in α‐oxalic acid dihydrate was measured using a multiple pulse, NMR technique. The high resolution proton speclia were recorded at room temperature.(AIP)