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Showing papers on "Oxalic acid published in 1975"


Journal ArticleDOI
TL;DR: This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalate-accumulating plants.
Abstract: l-Ascorbic acid-1-14C and its oxidation product, dehydro-l-ascorbic acid, produced labeled oxalic acid in oxalate-accumulating plants such as spinach seedlings (Spinacia oleracea) and the detached leaves of woodsorrel (Oxalis stricta and O. oregana), shamrock (Oxalis adenopylla), and begonia (Begonia evansiana). In O. oregana, conversion occurred equally well in the presence or absence of light. This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalic accumulation in plants.

99 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of protonation and conformation changes on the tensor elements and their orientations were investigated in three oxalates in order to determine the effects on the 13C chemical shielding tensors.
Abstract: 13C chemical shielding tensors in three oxalates were investigated in order to determine the effects of protonation and conformation changes on the tensor elements and their orientations. The experimental results, together with those in the accompanying paper [R. G. Griffin and D. J. Ruben, J. Chem. Phys. elding) of σ22 and in one case a concurrent rotation of the tensor about σ33, the element which is perpendicular to the COO plane. On the other hand, the simple conformational change of the twisting of carboxyl groups relative to one another, which occurs in diammonium oxalate monohydrate, results in small rotation of the tensor around σ11 and also may contribute to a decrease in the shielding of the σ22 component in this molecule. The orientation of the 13C tensor in oxalic acid dihydrate is different from that observed in other oxalate ions and carboxyl groups. The influence of a change in hydrogen bonding strength on tensor elements is discussed.

58 citations


Journal ArticleDOI
TL;DR: Evaluation of Histochemical technics for the identification of calcium oxalate showed Yasue's silver nitrate-rubeanic acid method to be the most satisfactory, while more frequently used methods for identifying calcium salts in tissues may give equivocal reactions.
Abstract: A case of pulmonary Aspergillus niger fungus ball is presented. Crystals of calcium oxalate, presumably derived from oxalic acid produced by the fungus, were deposited in tissues around the fungus ball. The crystals were identified by x-ray diffraction analysis. Histochemical technics for the identification of calcium oxalate were applied, and evaluation of those showed Yasue’s silver nitrate–rubeanic acid method to be the most satisfactory. More frequently used methods for identifying calcium salts in tissues may give equivocal reactions. Oxalic acid may cause localized tissue damage, and if this affects blood vessels severe hemorrhage may follow.

54 citations


Journal ArticleDOI
TL;DR: In some species practically all of the oxalic acid is tied up as Ca-oxalate as discussed by the authors, which is a strong chelating agent and once reacted with Ca it becomes somewhat...
Abstract: Calcium oxalate crystals were described in plant cells as early as 1865. Numerous accounts are found in the literature indicating that crystals occur in some species more abundantly than others and none occur in some plant species. The crystals have been observed and analyzed by transmitted light microscopy, polarized light microscopy, electron microprobe and by mechanical and chemical means. Plants that accumulate large quantities of oxalic acid generally tend to contain large quantities of Ca‐oxalate crystals which are insoluble in water, alkalies and organic acids. In some species practically all of the oxalic acid is tied up as Ca‐oxalate. Calcium oxalate crystals occur as mono and trihydrate salts in many crystalline forms. Crystals occur as united molecules called druses and sphaerites or as elongated crystals called styloids and raphids. Solitary crystals of different shapes and sizes may also be present. Oxalic acid is a strong chelating agent and once reacted with Ca it becomes somewhat ...

51 citations


Patent
25 Jun 1975
TL;DR: In this paper, the authors provided a set of implantable surgical articles which are at least partially bioresorbable and which consist at least part of a copolyester of succinic acid and oxalic acid possessing receiving units of the general formulae.
Abstract: Implantable surgical articles are provided which are at least partially bioresorbable and which consist at least partially of a copolyester of succinic acid and oxalic acid possessing receiving units of the general formulae: ##STR1## in which each R radical in the chain, which may be identical or different, represents a linear or branched alkylene radical possessing 2 to 6 carbon atoms, at least 2 of which carbon atoms form part of the polymer chain, a cyclo-alkylene radical possessing 5 to 8 carbon atoms, or a radical of the general formula: ##STR2## in which each of R 1 and R 2 , which may be identical or different, represents a methylene or ethylene radical. They are particularly suitable as sutures.

37 citations


Patent
07 Feb 1975
TL;DR: In this article, C 4 vanadium - phosphorus oxidation catalysts for producing maleic acid are prepared in an aqueous phosphoric acid solution using a reducing agent comprising an organic acid or aldehyde and a secondary alcohol such as oxalic acid and ethanol in a mole of 1:1 to 3 respectively, where an inorganic vanadium compound such as V 2 O 5 is dissolved and reduced to vanadium of 5 + valency or less.
Abstract: C 4 vanadium - phosphorus oxidation catalysts for producing maleic acid are prepared in an aqueous phosphoric acid solution using a reducing agent comprising an organic acid or aldehyde and a secondary alcohol such as oxalic acid and ethanol in a mole of 1:1 to 3 respectively, in which an inorganic vanadium compound such as V 2 O 5 is dissolved and reduced to vanadium of 5 + valency or less.

36 citations



Journal ArticleDOI
TL;DR: In this article, the dissociation constants of oxalic to azelaic acids, fumaric acid, and o-phthalic acid (H2A) were determined in acetonitrile.
Abstract: First and second dissociation constants, Ai and A2, and homoconjugation constants, A homo of the homologous se­ ries of oxalic to azelaic acids, fumaric acid, and o-phthalic acid (H2A), have been determined in acetonitrile. Also presented are the dissociation constant A(HE) and homoconjugation constant A(HE2~) of the corresponding mono methyl or ethyl es­ ters (HE). Using these data and eq 1, the following values of AT' = (HA -)/(HA~), HA - denoting the intramolecular hydro­ gen-bonded species, have been found: malonic 2.5 X 10 4, succinic S X 103, glutaric 6 X 102, adipic 4 X 101, azelaic 1.5 X 10', o-phthalic 3 X 105. The intramolecular hydrogen bond in HA - is quite stable, but the strength of this bond decreases with increasing distance between the carboxyl groups. No indication of HA - species has been found in the monofumarate ion. In all of the above acids the homoconjugate (HA-H2A)- is present in excess over (HA-H2A)-, the ratio (H3A2")/ (H3A2-) decreasing as A' decreases. Evidence has been presented that the monoesters and the diacids are not intramolecu­ lariy hydrogen bonded in acetonitrile.

32 citations


Patent
03 Jul 1975
TL;DR: In this article, a process for the production of ethylene glycol, alkali metal salts of glycine and glycolic acid by the hydrogenation of oxalic acid or an alkaline metal hydrogen oxalate, optionally in the presence of ammonia, was described.
Abstract: A process for the production of ethylene glycol, alkali metal salts of glycine, alkali metal salts of glycolic acid, alkali metal salts of diglycolic acid and alkali metal salts of nitrilotriacetic acid by the hydrogenation of oxalic acid or an alkali metal hydrogen oxalate, optionally in the presence of ammonia, said oxalic acid or alkali metal hydrogen oxalate containing less than two moles water of hydration.

32 citations



Patent
20 Oct 1975
TL;DR: In this paper, a method for preparing aqueous, radioactive waste solutions, from reprocessing plants for spent nuclear fuel and/or breeder materials and other nuclear plants, for noncontaminating solidification and removal of such solutions is provided.
Abstract: A method is provided for preparing aqueous, radioactive waste solutions, from reprocessing plants for spent nuclear fuel and/or breeder materials and other nuclear plants, for noncontaminating solidification and/or removal of such solutions. The total quantity of the various inorganic and organic substances in the waste solution is reduced by the destruction of nitric acid, nitrates and nitrites and the formation of a waste gas mixture which is practically free of higher nitrous oxides. To bring this about, the radioactive waste solutions are subjected to an electrolysis current at such current densities at the anode and at the cathode that in one process step the substances of the group hydrazine, hydroxylamine, oxalic acid, oxalates, tartaric acid and tartrates are oxidized at the anode and the substances of the group nitric acid, nitrates and nitrites are reduced at the cathode.

Journal ArticleDOI
TL;DR: Stopped-flow techniques are used; the concentrations of the reactants of the second-order reaction can be adjusted so that the transmittance signal remains nearly invariant for a wide range of voltage.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the aptitude of ethylene glycol as dissolved fuel for alkaline fuel cells using Raney nickel as electrocatalyst and found that about 75 percent of the glycol are oxidized to oxalate.


Patent
19 Nov 1975
TL;DR: In this paper, specific new oxalic acid diarylamides which are characterized by an asymmetrical substitution with regard to the central oxalinic amide moiety of the formula were introduced.
Abstract: The invention concerns specific new oxalic acid diarylamides which are characterized by an asymmetrical substitution with regard to the central oxalic amide moiety of the formula --NH--CO--CO--NH-- and by substitution with one or two alkoxy, alkenyloxy, aralkenyloxy or acyloxy groups. Definite additional substituents may be present. The compounds are valuable ultraviolet stabilizers.

Journal ArticleDOI
TL;DR: In this article, a method utilizing oxalate decarboxylase and potentiometry was described for the determination of oxalic acid, which was enzymatically decomposed to form formic acid and carbon dioxide.

Journal ArticleDOI
01 Mar 1975-Talanta
TL;DR: The kinetic inertness of the chromium(III) aquo-ion towards substitution reactions with oxalate has been exploited for selective separation of chromium from other elements.

Patent
31 Mar 1975
TL;DR: In this paper, the sizing compositions of an aqueous mixture of ammonia, an ammonium salt, and a rosin that is modified with from about 5 to 50 percent based on the weight of the rosin, of an organic acid compound selected from the group consisting of an α, β-unsaturated organic acid, an anhydride thereof, and their mixtures are presented.
Abstract: Novel sizing compositions comprising an aqueous mixture of ammonia, an ammonium salt, and a rosin that is modified with from about 5 to 50 percent based on the weight of the rosin, of an organic acidic compound selected from the group consisting of an α, β-unsaturated organic acid, an anhydride thereof, and their mixtures. In one embodiment, the ammonia and ammonium salt are produced as the reaction product of urea and an acid selected from the group consisting of sulfamic acid, phosphoric acid, oxalic acid, methane-sulfonic acid, trichloracetic acid, nitric acid, sulfuric acid, hydrochloric acid, stearic acid, and acetic acid. The method of making the sizing compositions and paper which is sized with the sizing compositions are also provided.

Journal ArticleDOI
TL;DR: In the presence of an alcohol, oxalic acid esters undergo diazomethane-catalyzed transesterification as mentioned in this paper, in which they undergo transesterization under mild reaction conditions.
Abstract: In the presence of an alcohol, oxalic acid esters undergo diazomethane-catalyzed transesterification. Under mild reaction conditions, esters of homologous dicarboxylic acids and other polycarboxyli...

Patent
Horst Meyer1
11 Mar 1975
TL;DR: In this paper, 2-NITROPHENYLPYRUVIC ACID with PotASSIUM PERMANGANATE in an alkaline medium is used to convert manganese oxide to soluble maganese-(II) salts with concurrent conversion of oxalic acid to carbon dioxide.
Abstract: 2-NITROBENZALDEHYDE, A VALUABLE CHEMICAL INTERMEDIATE, IS PREPARED THROUGH THE OXIDATION OF AN ALKALI METAL SALT OF 2-NITROPHENYLPYRUVIC ACID WITH POTASSIUM PERMANGANATE IN AN ALKALINE MEDIUM. Advantageously the requisite starting material is prepared directly by the reaction of 2-nitrotoluene and a diester of oxalic acid in the presence of an alcoholate and is then subjected to the oxidation without isolation. In a preferred embodiment the oxidation reaction mixture is acidified to convert the manganese-(IV) oxide to soluble maganese-(II) salts with concurrent conversion of oxalic acid to carbon dioxide. The process is industrially attractive in terms of the high yield, the availability of starting material and the ease of the manipulative steps involved.

Journal ArticleDOI
TL;DR: In this article, the tetraoxalato complex ion of the hafnium is extracted from aqueous oxalic acid solution with tri-n-octylamine in xylene solution.


Patent
05 Sep 1975
TL;DR: In this article, a method for the preparation of acicular particles of mixed oxalates of iron and of one or more metals of the group consisting of cobalt, nickel, copper, manganese, zinc, magnesium and cadmium is described.
Abstract: The invention concerns the preparation of acicular particles of mixed oxalates of iron and of one or more metals of the group consisting of cobalt, nickel, copper, manganese, zinc, magnesium and cadmium. The method consists in preparing a first solution containing cations of iron and of the divalent metal or metals, and a second solution containing oxalic acid, one of the said solutions further containing Cl - and SO 4 2 - anions and at least the second solution containing alcohol with preferably a light hydrocarbon. The first solution is poured very slowly (1 drop every 10 seconds) into the second one, conveniently at temperature below 0° C, while the latter is strongly stirred. The concentration in alcohol is preferably maintained at at least 50% in the second solution during the whole pouring process which should be effected with at least a slight excess of oxalic acid. The particles obtained may be treated for the preparation of solid solutions of oxides of iron and of the divalent metal or metals for the manufacture of magnetic tapes and the like.

Journal ArticleDOI
TL;DR: Succinimide, phenyl lactate, n-heptanoate, oxamic hydrazide, 2-oxoglutarate and ethinyl oestradiol all failed to reduce the urinary excretion of oxalic acid in male Wistar and Sprague-Dawley rats.
Abstract: Succinimide, phenyl lactate, n-heptanoate, oxamic hydrazide, 2-oxoglutarate and ethinyl oestradiol all failed to reduce the urinary excretion of oxalic acid in male Wistar and Sprague-Dawley rats. The

Journal ArticleDOI
TL;DR: In this article, the recovery of scandium was found to be about 95% in several minerals (naegite, allanite, yamaguchilite, lepidomelane, hokutolite) were analyzed.
Abstract: Scandium in several minerals { (0.0020.3) % Sc} was determined by the fluorometric method. The procedure is as follows : (0.050.1)g of mineral sample is treated with 30 ml of concentrated sulfuric acid for 3 hrs on a sand bath, and the solution is evaporated to dryness. The residue is dissolved in (35)ml of concentrated hydrochloric acid, and the solution is diluted to (7080)ml with water and filtered. Seventy milligrams of Ca2+ as a carrier and oxalic acid solution are added and the pH of the solution is adjusted to 2.0. After the solution has stood for ten minutes, the precipitate is centrifuged and decomposed by evaporating with perchloric acid to dryness. The residue is dissolved in 5 ml of 6M HCl. Scandium is separated by extracting at pH 1.6 with 10 ml of 0.2M TTA-benzene followed by backextracting with 10 ml of 1M HCl. The solution is made up to 25 ml, and an aliquot of the solution is taken. Two ml of 0.1% 2, 4-dihydroxybenzaldehyde-semicarbazone solution, 2 ml of 20% ammonium acetate solution are added, and the pH of the solution is adjusted to 6 with hydrochloric acid or ammonia, and the solution was diluted to 25 ml with water. The fluorescence intensity of the solution is measured (λexcitation360nm, λemission 425 nm).In this procedure, the recovery of scandium was found to be about 95%. Several mineral samples (naegite, allanite, yamaguchilite, lepidomelane, hokutolite) were analyzed.

Journal ArticleDOI
TL;DR: Aqueous solutions of aminophenazone were oxidized by excess hydrogen peroxide in acidic, neutral and alkaline media and the reaction was followed using thin-layer chromatography and spectrophotometry in the visible and uv regions as mentioned in this paper.


Journal ArticleDOI
TL;DR: The crystal structure of the title compound (I) has been determined from X-ray diffraction data as discussed by the authors, and the structure was solved by direct methods and refined by full-matrix least-squares to R 0·104 for 1895 three-dimensional diffractometer data.
Abstract: The crystal structure of the title compound (I) has been determined from X-ray diffraction data. Crystals are triclinic, a= 8·183(4), b= 14·449(6), c= 8·879(4)A, α= 125·00(3), β= 89·32(3), γ= 98·30(3)°, Z= 2, space group P. The structure was solved by direct methods and refined by full-matrix least-squares to R 0·104 for 1895 three-dimensional diffractometer data. There is considerable disorder in the positions of the oxalic acid and oxalate anion. The pyrrolidine ring adopts the envelope conformation with the nitrogen 0·54 A out of the plane of the carbon atoms, and the nitrogen substituent in the pseudo-equatorial position. The pyrrolidone ring is almost planar. The structure is linked by a series of hydrogen bonds between the oxotremorine cation and the oxalic acid and oxalate moieties.

Journal ArticleDOI
TL;DR: The following cyclic compounds were oxidized at 4° by means of aqueous sodium peroxide in large excess: 2,3,4,6/5-pentahydroxycyclohexanone (1), xylo -trihydroxy cyclohexane-1,2,3-trione (3), reductic acid (4), and ninhydrin (5).

Journal ArticleDOI
TL;DR: In this paper, the dissociation constants of oxalic to azelaic acids, fumaric acid, and o-phthalic acid (H2A) were determined in acetonitrile.
Abstract: First and second dissociation constants, Ai and A2, and homoconjugation constants, A homo of the homologous se­ ries of oxalic to azelaic acids, fumaric acid, and o-phthalic acid (H2A), have been determined in acetonitrile. Also presented are the dissociation constant A(HE) and homoconjugation constant A(HE2~) of the corresponding mono methyl or ethyl es­ ters (HE). Using these data and eq 1, the following values of AT' = (HA -)/(HA~), HA - denoting the intramolecular hydro­ gen-bonded species, have been found: malonic 2.5 X 10 4, succinic S X 103, glutaric 6 X 102, adipic 4 X 101, azelaic 1.5 X 10', o-phthalic 3 X 105. The intramolecular hydrogen bond in HA - is quite stable, but the strength of this bond decreases with increasing distance between the carboxyl groups. No indication of HA - species has been found in the monofumarate ion. In all of the above acids the homoconjugate (HA-H2A)- is present in excess over (HA-H2A)-, the ratio (H3A2")/ (H3A2-) decreasing as A' decreases. Evidence has been presented that the monoesters and the diacids are not intramolecu­ lariy hydrogen bonded in acetonitrile.