Copper Citrate Research Articles

The effect of citrate ions on the stress corrosion cracking of Al-Brass in acidic sulphate solutions

The addition of tri-sodium citrate to acidic copper sulphate solutions produces contrasting effects on the occurrence of the stress corrosion cracking (SCC) in Al-brass. Stimulating effects are observed in a wide range of low citrate concentrations (5 × 10−6 to 10−2 M) in which the formation of Cu2O deposits is delayed or suppressed. Inhibitive effects are observed at higher citrate concentrations at which the formation of crystalline copper citrate deposits takes place. The contrasting effects produced by citrates on the corrosive process are discussed in terms of the different weight that the formation of cuprous citrate complexes can have on the activity of the soluble copper species and, consequently, on the chemical and electrochemical equilibria at the metal/solution interface.

EPR study of copper(II) heterodinuclear citrate complexes

A study of the EPR frozen solution spectra of copper(II) citrate heterodinuclear species containing Mg(II), Zn(II) or Pd(II) has been carried out. The comparison of the spin Hamiltonian parameters suggests that copper(II) is in a coordination environment considerably different from that found in the case of the copper(II) mono-citrate complex. These results have been interpreted considering that two possible sites with different arrangements of oxygen donors are accessible to copper: a square-planar geometry for copper(II) heterodinuclear species containing Mg(Il) or Zn(II) or a tetragonally distorted octahedral geometry when the heterodinuclear species contains Pd(II).

Mixed-metal hydroxycarboxylic acid complexes. Formation constants of complexes of UVI with FeIII, AlIII, InIII and CuII

Formation constants for mixed-metal complexes, Kmmc, between uranium (VI), as the central metal ion, and each one of the metal ions iron(III), aluminium (III), indium(III) and copper(II) have been determined using data from potentiometric measurements. In each case one of the hydroxy-carboxylic acids, citric, tartaric or malic, was used as a ligand. At 298.15 K the values of –log Kmmc for the investigated systems are uranyl iron (II) citrate, 2.45; uranyl iron(III) malate, 7.37; uranyl aluminium(III) citrate, 8.21; aluminium(III) tartarate, > 12; uranyl aluminium (III) malate, 8.06; uranyl indium (III) citrate, 11.3; uranyl indium (III) tartarate, 7.88; uranyl indium(III) malate, 7.45; uranyl copper(II) citrate –1.41; uranyl copper (II) tartarate, –1.17; and uranyl copper(II) malate, –1.11.

Solution studies of systems with polynuclear complex formation. 4. Heteronuclear copper(II) citrate complexes with nickel(II) or magnesium(II)

The existence of heteronuclear complexes formed between citric acid, copper(II) and nickel(II) or magnesium(II) is demonstrated. The stoichiometry and stability of the complexes are reported. A volumetric example demonstrates the unexpectedly high stability of the CuNicitrate complex in comparison with the binary complexes and the interference of heteronuclear complex formation on citrate masking reactions. The paper also discusses the existence of heteronuclear cationic hydrolysis products.

AN IN SITU COMPARISON OF THE EFFECTIVENESS OF FOUR ALGICIDES1

ABSTRACT: Four algicides (copper citrate, copper ethanolamine, simazine, and diuron) were tested for effectiveness using in situ bio‐assays. Bioassays were conducted in clear polyethylene bags and algicide effectiveness measured by chlorophyll a, productivity, and algal counts. The body of water where this testing took place had a high pH (9.2), and high levels of total dissolved solids (610 mg/l) and nutrients. The order of effectiveness found in this study was simazine > diuron > copper ethanolamine > copper citrate.

Detection of low molecular weight copper(II) and zinc(II) binding ligands in ultrafiltered milks—the citrate connection

Low molecular weight zinc(II) and copper(II) binding ligands were detected in ultrafiltered human, bovine, and goat milk by the application of the method of modified gel chromatography. Human milk contains at least three detectable low molecular weight copper binders, whereas bovine and goat milk contain at least two. All three milks show two copper binding peaks with the same elution volumes. Zinc chromatograms were less specific than copper. Zinc showed only a single detectable low molecular weight binding ligand common to all three milks. Elution volumes for both zinc(II) and copper(II) citrate and picolinate systems were measured. Elution volumes of both copper(II) and zinc(II) citrate complexes are identical to elution volumes of an intense peak observed with all three milks; it is reasonable to assume that at least part of this peak corresponds to citrate. Human milk alone has a relatively intense binding peak for copper(II) at the same elution volume as the glutamate complex. Human and goat milk have another low intensity copper(II) binding ligand peak at the same elution volume; a number of amino acid complexes have binding peaks at this position. No peak characteristic of the zinc(II) or copper(II) picolinate systems could be found with any of the milks.

Three-dimensional electron microscopy of mitochondria and endoplasmic reticulum in the red muscle fiber of the rat diaphragm.

The three-dimensional arrangement of mitochondria and endoplasmic reticulum in the red muscle fiber was studied both in thick sections of the rat diaphragm fixed in glutaraldehyde and impregnated with uranyl acetate followed by lead and copper citrate, and in thin sections of glutaraldehyde fixed tissue treated with ferrocyanide-reduced osmium. The mitochondria were located either at the periphery of the fiber, where they were spherical, or between the myofibrils, where they formed longitudinal columns of rectangular, slightly flattened elements. From both types of mitochondria, thin, elongated branches arose at right angles that formed transversely oriented mitochondrial pairs at the I band level. At the periphery of the fiber, the endoplasmic reticulum took the appearance of a subsarcolemmal network of tubular cisternae oriented parallel to the cell surface. In the juxtanuclear region, it was made up of spherical masses composed of tightly knitted tubules that were interconnected by more loosely anastomosed tubules. In between the myofibrils, it was composed of longitudinally oriented repetitive units whose structure varied according to their position in from of the A or I bands of the myofibrils. In front of the A band, the endoplasmic reticulum appeared as a single sheet of anastomotic tubules compressed between the adjacent myofibrils, whereas at the I band level, its tubular elements passed in front and behind the transverse expansions of the mitochondria to form an intricate ultilayered network in from of the Z line.

Syndromes of cardiovascular malformations induced by copper citrate in hamsters.

Pregnant golden hamsters were injected intraperitoneally on the morning of the eighth day of gestation with a solution of copper citrate (2.7 mg/kg) or deionized water. Embryos were removed from the mothers by laparotomy on the 12th and 13th days of gestation, serially sectioned through the thorax, and examined for cardiac malformations. Twenty-one of the 37 edematous embryos from copper-treated mothers were affected with a total of 58 major cardiac anomalies. Sixteen of these embryos were affected with double outlet right ventricle in association with a membranous ventricular septal defect, two embryos contained hearts with overriding aortas, and three embryos were affected with isolated ventricular septal defects. Eleven of the 16 embryos with double outlet right ventricle were also affected with pulmonary trunk hypoplasia. The concept that these cardiac anomalies arise from a common pathogenetic basis is supported by the present model.

Solution studies of systems with polynuclear complex formation. 1. The copper(II) citrate system

The complex formation between copper(II) and citrate ions (citric acid = H 3L) has been investigated in the pH range of 4.5 to 10 by means of combined pH and pCu measurements. The emphasis was on the formation of the dimeric species and the concentration range chosen in the experiments favoured the formation of such species. The experimental data can be explained by the formation of the complexes Cu 2H −1L, Cu 2H −1L 3− 2, and Cu 2H −2L 4− 2. The last complex is the predominating species even in very dilute neutral and weakly alkaline solutions containing an excess of ligand. A more highly polymeric fraction is observed in neutral solutions with an excess of metal ion.

Copper-induced heart malformations in hamsters.

The injection of copper citrate into pregnant golden hamsters induces a specific pattern of cardiovascular malformations in their embroys. The syndrome consists of double-outlet right ventricle, pulmonary hypoplasia and a ventricular spetal defect.

Endoplasmic reticulum‐Golgi apparatus relationships in the rat spermatid

AbstractThe appearance of the spermatid Golgi apparatus was studied, both in thin sections of rat testes fixed in glutaraldehyde and treated with either tannic acid or ferrocyanide‐reduced osmium, and in relatively thick sections (0.25‐0.5 μm) of glutaraldehyde fixed tissue impregnated with uranyl acetate followed by lead and copper citrate. With any one of these three procedures, the Golgi apparatus of young spermatids examined at the Golgi and cap phases appeared as a compact hemispherical mass whose base was located next to the developing acrosomic system. The cortical region of the hemisphere was composed mainly of several stacks of saccules. The central core or medullary region contained numerous vesicular and tubular membranous profiles. Numerous cisternae of the endoplasmic reticulum (ER) were closely applied to the surface of the Golgi apparatus. In thin sections, the ER cisternae were separated from the stacks of saccules by small spherical or elongated membranous profiles. In thick sections, most of these elements formed a network of tubules, some of which being continuous with ER cisternae. Cisternae of the endoplasmic reticulum near the cis‐face of the Golgi stacks also branched and traversed the cortical region of the Golgi apparatus through gaps seen between the stacks of saccules to reach the central core region. Some of these were closely applied to the trans elements of Golgi stacks although never in continuity with them. Finally, ER cisternae were found located within the stacks themselves between Golgi saccules; here the membranes of the closely apposed cisternae of the endoplasmic reticulum and Golgi saccules remained separated by a space of about 12 nm. Thus, in the spermatid, the endoplasmic reticulum was closely related with all components of the Golgi apparatus.

The polarographic behaviour of copper complexes of pilocarpine and some related imidazoles

The polarographic behaviour of copper in the presence of citrate and pilocarpine and other imidazoles has been studied. The half-wave potentials of the copper(II)—copper(I) citrate system are controlled by the concentration of the second ligand when this is an imidazole nucleus. The effect can be used as the basis of an analytical procedure for these ligands.

Evolution of the endoplasmic reticulum during rat spermiogenesis.

AbstractThe endoplasmic reticulum (ER) was stained selectively by a sequence of uranyl acetate, lead and copper citrate, according to the method of Thiéry and Rambourg ('76), and then investigated in 0.5 to 2.0‐μm‐thick sections with the transmission electron microscope. Examination of photographic stereopairs allowed a three‐dimensional visualization of the ER at various steps of spermiogenesis.During the Golgi and cap phases of spermiogenesis (steps 1–7, classification of Leblond and Clermont, '52a), the ER is distributed throughout the cytoplasm as a three‐dimensional network of spherical and tubular cisternae connected by narrow tubules. In addition, a close network of tubular cisternae is located along the convex surface of the Golgi apparatus and lines the plasma membrane. Where the cell membrane joins that of another spermatid to form an intercellular bridge, this network extends across the bridge.During the acrosome phase (steps 8–14), the cytoplasm contains an abundant ER that shows the following modifications: (A) Along the inside and outside of the caudal tube the cisternae form long tubes or plates which run adjacent and parallel to the microtubules. These cisternae are connected by delicate lateral anastomoses; (B) Along the flagellum the ER forms a “fenestrated sleeve” made up of a close network of tubular cisternae; (C) Similar networks are organized as “fenestrated spherules” enclosing large vesicles seen throughout the cytoplasm; (D) At a short distance from the flagellum, the ER cisternae are continuous with a stack of annulate lamellae and an aggregate of radially arranged collapsed cisternae called the “radial body”.During the last or maturation phase (steps 15–19), the ER regresses. Thus, during the final steps in the formation of the flagellum, the ER network fragments and then most of the cisternae disappear from the cytoplasm. The “radial body” is the last element of the ER to be dissolved. Thus the ER undergoes extensive structural modifications during spermiogenesis, suggesting an active contribution of this organelle to the differentiation of the spermatid into a spermatozoon.

Crystal structure and magnetic properties of copper citrate dihydrate, Cu2C6H4O7.cntdot.2H2O

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure and magnetic properties of copper citrate dihydrate, Cu2C6H4O7.cntdot.2H2ODonald. Mastropaolo, Dana A. Powers, Joseph A. Potenza, and Harvey J. SchugarCite this: Inorg. Chem. 1976, 15, 6, 1444–1449Publication Date (Print):June 1, 1976Publication History Published online1 May 2002Published inissue 1 June 1976https://doi.org/10.1021/ic50160a038RIGHTS & PERMISSIONSArticle Views422Altmetric-Citations41LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (788 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Composition and Stability of Iron and Copper Citrate Complexes in Aqueous Solution

The acidity constants of citric acid and the stability constants of the citrate complexes of copper(II), iron(II), and iron(III) have been measured at 25 °C in 0.1 M KNO3 background. The measurements were based on mass balances on hydrogen ions, supplemented in the case of Cu(II) and Fe(III) complexes by measurements of free metal concentration with a solid-state copper-ion-sensitive electrode and a redox electrode respectively. The data required the assumption of a binuclear copper complex, but all complexes characterized were of 1:1 stoichiometry.

PENICILLAMINE-INDUCED NORMALIZATION OF CLINICAL SIGNS, AND LIVER MORPHOLOGY AND HISTOCHEMISTRY IN A CASE OF WILSON'S DISEASE

After 27 months of daily penicillamine administration (250 mg 3 or 4 times daily) a portal cirrhosis in a 10-year-old girl was found to have healed clinically and histopathologically. This case shows that even an advanced portal liver cirrhosis in Wilson's disease can be healed by adequate penicillamine therapy. Hence, it is important that all patients with liver cirrhosis who are younger than 30 years of age are examined for any signs of Wilson's disease. Copper metabolism studies with Cu64-labeled copper citrate revealed characteristic differences between the homozygote patient and her heterozygote parents and healthy subjects.

Stimulation of cytochrome c oxidation by a copper citrate complex

A copper-citrate complex acts catalytically to promote the oxidation of cytochrome c by a multistep mechanism The simplest interpretation of the data implies a stepwise reduction of copper-bound oxygen, the reaction showing saturation kinetics with respect to the catalyst.

A Copper-Molybdenum Complex: Its effects and movement in the piglet and sheep

Experiments were conducted to study the in vivo availability and movement of copper of a copper-molybdenum (Cu-Mo) complex. In baby pigs fed the Cu-Mo complex as the only copper supplement, serum copper levels were similar to those in pigs fed copper sulfate. However, the pigs receiving the Cu-Mo complex showed an increase in ceruloplasmin activity which was no greater than that in pigs fed a diet without supplemental copper. Tissue molybdenum concentrations were higher in pigs fed the Cu-Mo complex than in pigs fed an equal amount of molybdenum as the sodium salt. Conversely, tissue copper levels in the pigs fed the Cu-Mo complex were generally lower than those in pigs fed either copper sulfate or copper citrate plus sodium molybdate in equivalent amounts. In sheep given an intravenous injection of the Cu-Mo complex made from 64Cu and 99Mo, the rates of removal from the blood of the copper and molybdenum were equal, and this rate was more rapid than the removal of molybdenum when 99Mo was injected alone. Conversely, the rate of urinary excretion of molybdenum from the 64Cu-99Mo-injected sheep was slower than from the 99Mo-injected animal. These results support the hypothesis that copper bound in a Cu-Mo complex is biologically unavailable and indicate that such a complex can exist in vivo.

Electron Spin Resonance of Copper (II) Citrate Chelates

Electron spin resonance (ESR), paramagnetic susceptibility, and polarographic measurements have been made of copper (II) citrate chelates over a wide range of pH. The signal observed at pH 4 is typical of that found for copper (II) in a distorted octahedral environment. With increasing pH the signal becomes less intense and is replaced by a much broader spin resonance observable at relatively high concentrations of copper (II) and in frozen solutions. At pH's of about 11, a third signal is observed. The broad signal has been interpreted in terms of dipole—dipole coupling of copper (II) ions arising from dimer formation. Measurements show that the paramagnetic susceptibility is independent of pH. Solution of the spin Hamiltonian including the dipole—dipole interaction has made possible calculation of the line shape for the dimer signal. The calculations have led to a value of 3.1 Å as the distance between the copper (II) dipoles and to the conclusion that each copper (II) ion is in a | 3z2—r2〉 ground state rather than | x2—y2〉. The ESR data provides very strong evidence for the formation of a dimer in solution and allows reinterpretation of the data found in the literature. The signal observed beyond pH 11, with its partly resolved hyperfine structure at room temperature, is attributed to a monomer formed as a result of replacement of the hydrogen from the hydroxy group of the citrate anion by copper (II).