Showing papers on "Oxalic acid published in 1979"
TL;DR: In this paper, a barley seedlings (Hordeum vulgare L. var. distichon ALEFELD) was purified to homogeneity as determined by disc gel electrophoresis.
Abstract: Oxalate oxidase from barley seedlings (Hordeum vulgare L. var. distichon ALEFELD) was purified to homogeneity as determined by disc gel electrophoresis. The enzyme hydrolyzed oxalate, but no other related acids. The optimum pH was around pH 3.5, and this enzyme was stable at acidic pHs. The enzyme appears to consist of two identical subunits. Various other properties were investigated.
95 citations
84 citations
TL;DR: In this article, the initial hydration of C3S was found to be stimulated by adding to the paste pre-hydrated C 3S and by lowering the Ca++ concentration of the liquid phase with oxalic acid.
68 citations
TL;DR: A system for the determination of oxalic acid in human urine using ion exchange-ion pair, high performance liquid chromatography with electrochemical detection (HPLCEC), and Quantitative data are obtained by the method of standard addition in the clinically significant range from 5 to 40 mg/liter.
Abstract: A system for the determination of oxalic acid in human urine using ion exchange-ion pair, high performance liquid chromatography with electrochemical detection (HPLCEC) is described. Urine is acidified with HCl, and excess CaCl2 is added to precipitate oxalate ion. The precipitate is isolated, redissolved in dilute sulfuric acid, and separated on a strong cation exchange column using an acetic acid-solium acetate-tetrabutylammonium tetrafluoroborate mobile phase adjusted to pH 2.8. Using an electrochemical detector at 1.25 volts vs. the saturated calomel electrode (SCE), oxalic acid exhibits a linear dynamic range from 1 to 1000 mg/liter with a detection limit of 0.1 mg/liter. Quantitative data are obtained by the method of standard addition in the clinically significant range from 5 to 40 mg/liter. Percentage recovery for spiked urine samples was 97.8% with a relative standard deviation of 2.5%.
32 citations
TL;DR: The enantiomeric specificity of ascorbic acid metabolism was established in geranium by comparing the incorporation of d - and l -ascorbic acid-[6- 14 C] in the presence of l-ascorbric acid-[4- 3 H] as discussed by the authors.
28 citations
Patent•
31 Aug 1979TL;DR: In this article, a biphenyl compound is produced from a corresponding aromatic monocyclic compound at a high yield thereof and a high percent selectivity by dehydrogenatively dimerizing the compound with molecular oxygen in the presence of oxalic acid together with a organic palladium salt catalyst.
Abstract: A biphenyl compound is produced from a corresponding aromatic monocyclic compound at a high yield thereof and a high percent selectivity thereto, by dehydrogenatively dimerizing the aromatic monocyclic compound with molecular oxygen in the presence of oxalic acid together with a organic palladium salt catalyst, under a pressure higher than the atmospheric pressure.
23 citations
TL;DR: The method described is insensitive to various interfering factors, such as reducing and oxidizing substances, cloudy or colored samples, and therefore also suitable for oxalate determination in food technology and plant breeding.
Abstract: The oxalate content of urine is determined by means of oxalate oxidase and simple pH measurement. The enzyme specifically decarboxylates oxalate, producing two moles CO2 per mole oxalate. The CO2 diffuses into an alkaline buffer solution (Hallson, P. C. & Rose, G. A. (1974), Clin. Chim. Acta 55, 29--39) in the closed reaction vessel, and reduces the pH value, which is measured with an electrode. Only 125 microliter native urine is required to measure oxalate concentrations in the range of 80 mumol/l to 1.6 mmol/l (corresponding to 7 to 144 mg anhydrous oxalic acid per liter). The limit of detection is 10 nmol oxalate, and the accuracy is 101% with a coefficient of variation of 6%. The method described is insensitive to various interfering factors, such as reducing and oxidizing substances, cloudy or colored samples. It is therefore also suitable for oxalate determination in food technology and plant breeding.
21 citations
TL;DR: In this paper, the effect of different inorganic (HCl, H 2 SO 4, H 3 PO 4 ) and organic additives was studied for the simultaneous adsorption of Cl − ions and urea on platinized platinum electrodes under different experimental conditions.
21 citations
TL;DR: A rapid gas chromatographic method has been developed which dispenses with separation operations and measures oxalic acid as a diethylester by means of back-flushing, and using malonic acid as an internal standard.
Abstract: The known methods of oxalic acid determination are not suitable for reliable, rapid and economical routine analysis. A rapid gas chromatographic method has been developed which dispenses with separation operations and measures oxalic acid as a diethylester by means of back-flushing, and using malonic acid as an internal standard. One determination can be conducted within 6 to 8 min. and preparation of the specimen takes about the same amount of time. If the gas chromatographic conditions are changed and more time is permitted for analysis, numerous other extractable acidic metabolites can also be determined.
21 citations
TL;DR: Data clearly indicate that oxalogenesis occurs during the assay of plasma, even under the mildest of separation conditions, as determined by the electron capture-gas chromatographic procedure.
20 citations
Patent•
23 Apr 1979
TL;DR: Froth flotation method for recovering copper, nickel, silver, mercury, bismuth, and lead values from their ores by applying thiourea or any substituted thourea in conjunction with hydrochloric, nitric, sulfuric, phosphoric, oxalic, hexacyanoferric (II), thiocyanic, or cyanic acids as discussed by the authors.
Abstract: Froth flotation method for recovering copper, nickel, silver, mercury, bismuth, and lead values from their ores by applying thiourea or any substituted thiourea in conjunction with hydrochloric, nitric, sulfuric, phosphoric, oxalic, hexacyanoferric (II), thiocyanic, or cyanic acids to obtain pure copper, nickel, silver, mercury, bismuth, and lead concentrates, which comprises; adding to a water suspension of finely divided ore of thiourea, or substituted thiourea, and an adequate amount of the above said acids, and especially for recovering of copper minerals the addition comprises hydrochloric, nitric at a pH 6.5, sulfuric, phosphoric, oxalic, hexacyanoferric (II), cyanic at a pH 7.0 of the mineral slurry; for recovering nickel minerals, thiocyanic acid, i.e., potassium thiocyanate in a neutral pulp of mineral slurry; for recovering silver mineral or native silver, hydrochloric, nitric, or oxalic acid in a slightly acid pulp of mineral slurry at a pH 6-6.5; for recovering mercury minerals hydrochloric or nitric acid, or potassium thiocyanate at a pH 7.0 of the mineral slurry; for recovering bismuth minerals or native bismuth, hydrochloric or nitric acid in a slightly alkaline pulp of mineral slurry at a pH 8.0, by adding sodium hydroxide, ammonia, or alkyl amine, and adding a small amount of sodium chloride; for recovering of lead minerals, nitric acid at a pH 6.5, or potassium thiocyanate in a neutral pulp of mineral slurry, which acting in conjunction activate and levitate in the froth developed by an usual frother and by usual froth flotation procedure the metal values of copper, nickel, silver, mercury, bismuth, and lead minerals are recovered from respective mineral slurries of unaffected gangue minerals as froth concentrates.
TL;DR: Biosynthetic rates calculated from the product of pool size and turnover are in excellent agreement with urinary excretion rates, confirming directly that urinary oxalate is a quantitative index of biosynthesis.
TL;DR: The enhanced selectivity realized by use of the differential pulse electrochemical detection mode is demonstrated.
Abstract: Oxalic acid determinations are made using two modes of electrochemical detection, namely, classical d.c. and differential pulse, after separation by ion-pair, ion exchange high performance liquid chromatography. Peak height ratio plots are constructed and compared for uric acid and oxalic acid mixtures using both electrochemical detection modes. The enhanced selectivity realized by use of the differential pulse electrochemical detection mode is demonstrated.
Patent•
29 Jan 1979
TL;DR: In this paper, a froth flotation process using commercial amines in conjunction with oxalic acid or alkali oxalates to obtain pure concentrates of said metal values is described.
Abstract: Beneficiation of metallic ores selected from the group of zinc, bismuth, cobalt, nickel, titanium, zirconium, thorium, chromium, molybdenum, wolfram, and uranium, by froth flotation process using commercial amines in conjunction with oxalic acid or alkali oxalates to obtain pure concentrates of said metal values comprises; adding to a water suspension of finely divided ore of amine type collectors and an adequate amount of oxalic acid or a soluble oxalate which acting in conjunction activate and levitate in the froth by usual froth flotation process the metal values of zinc, bismuth, cobalt, nickel, titanium, zirconium, chromium, and uranium minerals; and for molybdenum and wolfram recovering the pulp of mineral slurry are oxidized with hydrogen peroxide, or any strong oxidizing agent and proceed as described above.
TL;DR: The C,C-bond cleavage which occurs during chromic acid oxidation of t-butylphenylmethanol (1) and 1,2-diphenylethanol (2) to the extent of up to 67% is reduced to 3% for 1 and 13% for 2 when the reaction is run in acetone, and totally suppressed upon co-oxidation of the alcohols 1 and 2 with oxalic acid.
Abstract: The C,C-bond cleavage which occurs during chromic acid oxidation of t-butylphenylmethanol (1) and 1,2-diphenylethanol (2) to the extent of up to 67% is reduced to 3% for 1 and 13% for 2 when the reaction is run in acetone, and totally suppressed upon co-oxidation of the alcohols 1 and 2 with oxalic acid. Similarly, the yield of 7-norbornanone obtained from 7-norbornanol (7) is raised in going from acetic acid (24%) to acetone (41%) and approaches 100% in the co-oxidation. With the co-oxidation 5-endo-bicyclo [2.1.1]hexanol (3) is converted to the corresponding ketone in 54% yield. Mechanistic implications of these results are discussed.
TL;DR: A macroreticular polystyrene-based chelating resin with the nitrosoresorcinol group as the functional group has been synthesized and shows selectivity for copper(II), iron(III), and cobalt(II).
TL;DR: The anion-exchange behaviour of 30 metal ions on a weakly basic ion-exchanger (DEAE-cellulose) has been investigated in aqueous oxalic acid media over the concentration range 0.0010-0.50 M; the system offers good prospects for group separations.
TL;DR: In this paper, the vibrational and 1H NMR spectra of 2-10 are discussed and the crystal and molecular structure of tetrachloro-N-methylamino oxalato-O,O′-antimony(V) is determined by X-ray analysis.
Abstract: Abstract Oxalic acid dimethylester and the oxalic acid methylester-N-methylamides 2 and 4, resp., react with antimony(V) chloride to yield the 1 : 1 addition compound 5 or the cyclic tetrachloroantimony(V) compounds 1, 3 and 6, resp., which represent SbO2C2 and SbONC2 five ring systems, resp. Li oxalic acid methylester-N-methylimide (9) and anti-mony(V) chloride gives the bicyclic octachloro-N-methylamido oxalato-O,O′-O,N-diantimony(V) (10). The crystal and molecular structure of tetrachloro-N-methylamino oxalato-O,O′-antimony(V) (3) is determined by X-ray analysis. The vibrational and 1H NMR spectra of 2-10 are reported and discussed.
TL;DR: In this article, the authors present a very mild and convenient route to both title compounds starting from the corresponding methyl or ethyl acetylenedicarboxylates, which are usually prepared as their sodium salts by Claisen condensations with acetic and oxalic acid esters and strong bases such as sodium alkoxides as catalysts.
TL;DR: In this article, a trivalent thallium is precipitated in the presence of oxalic acid and the resulting mixture is shown to be a mixture of 25% of thallous oxide and 75% of ammonium-thallous oxalate.
Patent•
22 Mar 1979
TL;DR: In this paper, the authors presented a method to obtain the title compound suitable for a raw material for an epoxy resin, having a specific composition, in high yield, by the reaction of phenol with HCHO in a specific ratio in the presence of oxalic acid in an inert atmosphere, and then by removing the excessive phenol through distillation.
Abstract: PURPOSE: To obtain the title compound suitable for a raw material for an epoxy resin, having a specific composition, in high yield, by the reaction of phenol with HCHO in a specific ratio in the presence of oxalic acid in an inert atmosphere, and then by removing the excessive phenol through distillation. CONSTITUTION: Phenol (P) is reacted with formaldehyde (F) in the molar ratio range of F to P of 0.02W0.04:1, in the presence of oxalic acid in an amount of 0.01W5wt% based on P, in an inert atmosphere, at 50W110°C, and the excessive P is distilled out of the reaction product to obtain the title compound containing 10W 25wt% of 2,2'-dihydroxydiphenylmethane, 40W60wt% of 2,4-dihydroxydiphenylmethane, and 25W40wt% of 4,4'-dihydroxydiphenylmethane, in high yield, with controlled contents unreacted P and high-degree condensate. COPYRIGHT: (C)1980,JPO&Japio
Patent•
[...]
27 Jun 1979
TL;DR: In this article, the authors proposed to bring an aqueous solution containing both specific anion and aluminium ion into contact with the scale contg. calcium oxalate adhered to the surface of the base material of an apparatus.
Abstract: PURPOSE: To dissolve and remove the scale adhered to apparatus, etc., safely, effectively, and quickly by bringing an aqueous solution containing both specific anion and aluminium ion into contact with the scale contg. calcium oxalate adhered to the surface of the base material of an apparatus, etc. CONSTITUTION: An aqueous solution containing both an anion (A): selected from hydrochloric acid, nitric acid, sulfamic acid, formic acid, acetic acid, glycolic acid, oxalic acid, lactic acid, malonic acid, malic acid, tartaric acid, citric acid, and gluconic acid; and aluminum ion (B) is brought into contact with the scale contg. calcium oxalate adhered to the surface of a base material of an apparatus, etc. The preferred proportion of the component (A) to the component (B) is almost 1:1 in equivalent, and also the preferred contacting temperature between the aqueous solution and the scale is 50W70°C. COPYRIGHT: (C)1981,JPO&Japio
Patent•
29 Sep 1979
TL;DR: In this paper, a metal salt of organic acid (or bleaching agent) which is prepared by coordinating a metal ion such as iron or copper is contained in a quantity of (a) about 2 to 50 g/litter together with hydrogen peroxide (or a strengthening agent) in a quantities of (b) about 0.3 to 20 g/ litter in an organic acid such as aminopolycarbonic acid (e.g., ethylene diamine tetraacetate), oxalic acid or amino poly phosphate).
Abstract: PURPOSE:To effectively strengthen a color image in a stable manner and without any fog by using a bath containing a special complex metal salt of organic acid and hydrogen peroxide so that the photographic material after image exposure has its color image strengthened and treated. CONSTITUTION:A metal salt of organic acid (or bleaching agent) which is prepared by coordinating a metal ion such as iron or copper is contained in a quantity of (a) about 2 to 50 g/litter together with hydrogen peroxide (or a strengthening agent) in a quantity of (b) about 0.3 to 20 g/litter in an organic acid such as aminopolycarbonic acid (e.g., ethylene diamine tetraacetate), oxalic acid or amino poly phosphate. A treating bath having a pH higher than about 8 (preferably, 10 to 14) is used to treat a color photographic material of silver halide after the exposure in the presence of an image silver and a main color developing agent. Incidentally, a solvent of silver halide such as potassium thiosulfate or thiourea is preferably used in addition. According to the present method, moreover, the quantity of the photosensitive material can be reduced to a level of about one quatter of the conventional method.
Patent•
05 Apr 1979
TL;DR: In this paper, an org. Pd catalyst is used to accelerate a coupling reaction in a solventless state and mixing an alkali metal carbonate and a reducing agent into the resulting soln is agitated for 10minW10hr.
Abstract: PURPOSE: To separation-recover Pd as metallic Pd in a high yield by subjecting an arom. cpd. to oxidation coupling reaction in the presence of an org. Pd catalyst in a solventless state and mixing an alkali metal carbonate and a reducing agent into the resulting soln. CONSTITUTION: An arom. cpd. such as benzene, toluene or xylene is dehydrogenation-dimerized in the presence of an org. Pd catalyst such as Pd salt of aliph. carboxylic acid in a solventless phase under a press. of 2W200kg/cm 2 at a temp. of 40W300°C to form a biphenyl cpd. To the resulting soln. after the oxidation coupling reaction is added a carbonate such as Na 2 CO 3 , K 2 CO 3 or Li 2 CO 3 , a hydrogencarbonate such as NaHCO 3 or KHCO 3 or other alkali metal carbonate in an amt. of 0.01W10g per kg of the soln., and they are mixed. After adding a reducing agent such as hydrogen gas, formic acid or oxalic acid the mixed soln. is agitated for 10minW10hr. Pd contained is deposited as large particles of 30μ or more and recovered in a high yield. COPYRIGHT: (C)1980,JPO&Japio
Patent•
02 Feb 1979
TL;DR: In this paper, the title product free from precipitation by adding FeSO 4 and an oxidizing agent to an aq Fe 2 (SO 4 ) 3 soln so as to specify the total SO 4 2 to total Fe ion molar ratio in the presence of Cl - or Cl - and oxalic acid or the like.
Abstract: PURPOSE: To manufacture the title product free from precipitation by adding FeSO 4 and an oxidizing agent to an aq Fe 2 (SO 4 ) 3 soln so as to specify the total SO 4 2- to total Fe ion molar ratio in the presence of Cl - or Cl - and oxalic acid or the like CONSTITUTION: FeSO 4 and an oxidizing agent is added to an aq Fe 2 (SO 4 ) 3 soln so as to adjust the total SO 4 2- to total Fe ion molar ratio to 14 or less, and they are reacted at about 50W80°C in the presence of Cl - in an amt of about 5W10wt% to the total Fe ion amt or the Cl - and about 01% of one or more kinds of cpds selected from oxalic acid, citric acid, polycarboxylic acid, (tripoly or pyro)phosphoric acid, hexametaphosphoric acid, dodecylbenzenesulfonic acid, oleic acid salts thereof COPYRIGHT: (C)1980,JPO&Japio
TL;DR: In this article, the thermal expansion tensor at 295.1 K was calculated from the changes of the lattice constants with temperature and the elements of the thermalexpansion tensor were shown to be a~ = -1 (5), a 2 = 29 (6) and tt3 = 199 (10) × 10 -6 K-I.
Abstract: Urea-oxalic acid, CH4N20.C2H204, mono- clinic, space group C2/c, a = 13.0625 (7), b = 6.6437 (2), c = 6.8478 (3) .A, fl = 92.474 (6) ° (at 295 (1) K), Z = 4, d c = 1.68 Mg m -a, R w = 5.9%. The structure consists of layers of urea and oxalic acid molecules held together by hydrogen bonds. The thermal-expansion tensor has been calculated from the changes of the lattice constants with temperature. The elements of the thermal-expansion tensor at 295.1 K are a~ = -1 (5), a 2 = 29 (6) and tt3 = 199 (10) × 10 -6 K-I.
TL;DR: In this paper, a combined cation-exchange separation method is described for the determination of cobalt in silicate rocks. But the method is not suitable for the analysis of complex matrices with high selectivity.
Abstract: A combined cation-exchange separation — atomic absorption spectrophotometric method is described for the determination of cobalt in silicate rocks. Silicate is decomposed with a mixture of perchloric acid — hydrofluoric acid. The residue is fed on a Bio-Rad AG 50W, X-8 resin (hydrogen form) column from 0.5 M hydrochloric acid — 0.05 M oxalic acid — 1.5% hydrogen peroxide solution. Polyvalent ions including ferric ions are not adsorbed on the column, while cobalt is retained together with alkaline earths and aluminium. Then, cobalt can be stripped selectively by elution with 1 M hydrochloric acid in 84% acetone solution and can subsequently be determined by AAS. The single column ion-exchange method described allows cobalt to be isolated from complicated matrices with good selectivity, sufficient enough to permit the final determination spectrophotometrically. Quantitative results are presented for the determination of cobalt in international rock standards and iron metal.