Showing papers on "Antimony published in 2000"
TL;DR: In this paper, the effect of solution pH on the removal efficiency of arsenic and antimony for drinking water using recently developed RO membranes was investigated and it was demonstrated that pH control for the membranefeed water is more essential for the successful removal of arsenic compounds than the case of antimony compounds.
267 citations
TL;DR: Despite the high antimony contamination of the soils, concentrations in the investigated plants in general corresponded to concentrations only reported for uncontaminated soils, and a correlation between the mobile fraction in the soils and antimony in leaves was found.
191 citations
TL;DR: The coordination of antimony in the SnO2 nanocrystallites has been investigated by extended x-ray absorption fine structure measurements (EXAFS) at the Sb K-edge at 5 K while its valence state was determined by near edge X-ray infrared fine structure measurement (XANES) at Sb L1 edge as mentioned in this paper.
Abstract: Colloids of nanocrystalline tin dioxide containing 9.1 at. % and 16.7 at. % antimony have been prepared by the coprecipitation method. High-resolution transmission electron microscopy (TEM) images show crystalline particles in the 2–6 nm size regime. X-ray powder diffraction patterns of nanocrystalline powders obtained by drying the colloids and heating to 100 °C indicate the same rutile lattice structure known from bulk SnO2. On heating to 500 °C in air, the nanocrystalline powder shows a slight increase in particle size but especially a change in color from yellowish to bluish which is accompanied by the development of n-type conductivity. The coordination of antimony in the SnO2 nanocrystallites has been investigated by extended x-ray absorption fine structure measurements (EXAFS) at the Sb K-edge at 5 K while its valence state was determined by near edge x-ray absorption fine structure measurements (XANES) at the Sb L1 edge. The Sb higher neighbor shell distances in the doped material differ from the ...
172 citations
TL;DR: In this paper, aqueous colloid of n-doped tin dioxide nanoparticles in the 4−9nm size regime has been prepared hydrothermally either by inducing oxygen vacancies into the SnO2 lattice or by doping the nanoparticles with antimony.
Abstract: Blue-colored aqueous colloids of n-doped tin dioxide nanoparticles in the 4−9-nm size regime have been prepared hydrothermally either by inducing oxygen vacancies into the SnO2 lattice or by doping the nanoparticles with antimony. Autoclavation at temperatures above 250 °C is found to be necessary to achieve n-doping of the particles. Blue-colored oxygen-deficient nanoparticles are obtained in the absence of antimony by employing a reducing atmosphere inside the autoclave. If these colloids are exposed to air, their blue color vanishes within 1 day, indicating back reaction of the vacancies with oxygen. Antimony-doped tin dioxide nanoparticles have been prepared by using either SbIIICl3 or SbVCl5 as the source of antimony. In contrast to the oxygen-deficient tin dioxide, the blue color of antimony-doped nanoparticles is stable in air. The blue color of the colloids corresponds to a broad absorption peak in the red and IR regions, independent of the method of n-doping. As for bulk material, this IR absorpt...
131 citations
TL;DR: The adsorption behavior of rice husks for antimony ions from aqueous solutions has been investigated as a function of appropriate electrolyte, equilibration time, hydrogen ions, amount of adsorbent, concentration of Adsorbate, effect of diverse ions and temperature.
121 citations
TL;DR: The stability of arsenic, selenium, antimony and tellurium species in water and urine as well as in extracts of fish and soil certified reference materials has been investigated and losses and species transformations during extraction processes were investigated.
Abstract: The stability of arsenic, selenium, antimony and tellurium species in water and urine (NIST SRM 2670n) as well as in extracts of fish and soil certified reference materials (DORM-2 and NIST SRM 2710) has been investigated. Stability studies were carried out with As(III), As(V), arsenobetaine, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), phenylarsonic acid (PAA), Se(IV), Se(VI), selenomethionine, Sb(III), Sb(V) and Te(VI). Speciation analysis was performed by on-line coupling of anion exchange high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Best storage of aqueous mixtures of the examined species was achieved at 3 degrees C whereas at -20 degrees C species transformation especially of selenomethionine and Sb(V) took place and a new selenium species appeared within a period of 30 days. Losses and species transformations during extraction processes were investigated. Extraction of the spiked fish material with methanol/water led to partial conversion of Sb(III), Sb(V) and selenomethionine to two new antimony and one new selenium species. The other arsenic, selenium and tellurium species were almost quantitatively extracted. For soil spiked with MMA, PAA, Se(IV) and Sb(III), recoveries after extraction with water and sulfuric acid (0.01 mol/L) were below 20%.
107 citations
TL;DR: The spin-echo 1H-NMR data show that Sb(III) rapidly entered red blood cell walls and was complexed by intracellular glutathione, indicating that facile exchange may be important in the transport of Sb (III) in various biofluids and tissues in vivo.
Abstract: The tripeptide glutathione (gamma-L-Glu-L-Cys-Gly, GSH) is thought to play an important role in the biological processing of antimony drugs. We have studied the complexation of the antileishmanial drug potassium antimony(III) tartrate to GSH in both aqueous solution and intact red blood cells by NMR spectroscopy and electrospray ionization mass spectrometry. The deprotonated thiol group of the cysteine residue is shown to be the only binding site for Sb(III), and a complex with the stoichiometry [Sb(GS)3] is formed. The stability constant for [Sb(GS)3] was determined to be log K 25 (I = 0.1 M, 298 K) based on a competition reaction between tartrate and GSH at different pH* values. In spite of being highly thermodynamically stable, the complex is kinetically labile. The rate of exchange of GSH between its free and Sb-bound form is pH-dependent, ranging from slow exchange on the 1H-NMR timescale at low pH (2 s-1 at pH 3.2) to relatively rapid exchange at biological pH (> 440 s-1). Such facile exchange may be important in the transport of Sb(III) in various biofluids and tissues in vivo. Our spin-echo 1H-NMR data show that Sb(III) rapidly entered red blood cell walls and was complexed by intracellular glutathione.
90 citations
TL;DR: Methodologies for the environmental analysis of total antimony and aqueous chemical speciation are critically reviewed, including preparation techniques for aqueously and solid matrices and the determination of solid state partitioning and recommendations are given for future research directions.
Abstract: Methodologies for the environmental analysis of total antimony and aqueous chemical speciation are critically reviewed, including preparation techniques for aqueous and solid matrices and the determination of solid state partitioning and recommendations are given for future research directions. Concentrations of total antimony commonly present in aqueous and solid environmental samples are readily determined using present day analytical techniques. This has resulted primarily from technological advances in microwave digestion for solid matrices and the development of plasma based analyte detection systems. ICP-AES and ICP-MS techniques are both utilised for the environmental analysis of total antimony concentrations. However, ICP-MS is increasingly favoured as a result of reduced spectral interferences and the potential for analyte detection in the pg mL(-1) range. Determination of aqueous antimony speciation presents a number of complex analytical challenges and highly selective separation and identification techniques are required prior to detection. The majority of published techniques including common applications of hydride generation are insufficiently selective for the determination of intrinsic chemical speciation and often only oxidation state data are obtained. The recent in-line applications of HPLC-ICP-MS offer the potential for highly selective separations of aqueous antimony species and determination of detailed chemical speciation data. However, considerable development work is required to optimise chromatographic separations and identify uncharacterised species resident in environmental systems. Analytical techniques to aid the determination of antimony's associations with solid environmental matrices include the application of chemical extraction procedures and leaching experiments. To date, this area of analytical research has received little attention and further studies are required to elucidate this aspect of antimony's environmental chemistry.
82 citations
TL;DR: In this paper, the best conditions for alkaline leaching of a refractory gold-bearing stibnite (Sb 2 S 3 ) coming from South America were investigated.
80 citations
TL;DR: Spinel-type lithium antimony manganese oxide was first synthesized by aging the precipitates that were obtained by reaction of a mixed aqueous and antimony compounds (Sb/Mn = 0.25) with (LiOH + H2O2)INE solution, followed by hydrothermal treatment at 120°C.
Abstract: Spinel-type lithium antimony manganese oxide was first synthesized
by aging the precipitates that were obtained by reaction of a mixed aqueous
solution of manganese(II) and antimony(V)
chlorides (Sb/Mn = 0.25) with (LiOH + H2O2)
solution, followed by hydrothermal treatment at 120 °C. A well
crystallized spinel-type solid with a chemical composition of Li1.16Sb(V)0.29Mn(III)0.77Mn(IV)0.77O4
was obtained; it had the characteristic of including mixed valence manganese.
The spinel structure was preserved during heating up to 600 °C.
Most of the lithium ions in the prepared material could be extracted by treating
with an acid; the extraction progressed topotactically, preserving the spinel
structure, accompanied by a decrease in the lattice constant from 8.31 ± 0.01 A
to 8.13 ± 0.01 A. The mean oxidation of manganese
increased from 3.50 to 3.98 after acid treatment, due to the disproportionation
of trivalent manganese. The DTA-TG analysis and IR spectra showed the
formation of lattice protons exchangeable with lithium ions. The pH titration
study showed that the acid treated sample had a remarkable lithium ion-sieve
property over the entire pH range studied. The affinity order was K < Na ≪ Li
and the exchange capacity reached 5.6 mmol g−1
for Li+. It showed a selective uptake of 14 mg g−1
of Li+ from LiCl enriched seawater.
72 citations
TL;DR: In this article, the authors used inductively coupled plasma emission spectroscopy, reflectance spectrography and X-ray diffraction to study 7th-century AD glass fragments from the Crypta Balbi in Rome.
Abstract: Inductively coupled plasma emission spectroscopy, reflectance spectroscopy and X-ray diffraction were used to study seventh-century AD glass fragments from the Crypta Balbi in Rome. All the samples were found to be silica-soda-lime glasses. Iron determines the colour of blue-green, green and yellow-green transparent glasses; chemical composition suggests deliberate addition of iron and/or manganese in about half the samples. Copper was found as the main colourant in red, pale blue and blue-green opaque fragments; elemental copper acts as an opacifier in red glass, and calcium antimonate in white, pale blue and blue-green glasses. Detection of antimony in transparent fragments suggests recycling of opaque mosaic tesserae.
TL;DR: In this article, the speciation of antimony species in airborne particulate matter (APM) was performed using both anion-exchange and size-exclusion for HPLC-ICP-MS detection.
Abstract: There is a considerably increasing concern about the
speciation of antimony because anthropogenic emission has resulted in an
increasing concentration of antimony in the environment. Apart from
inorganic Sb species, methylated Sb species have been detected in a variety
of environmental samples. However, little is known about the distribution
of Sb species in airborne particulate matter (APM). The speciation of Sb
species in APM was performed using both anion-exchange and size-exclusion
HPLC-ICP-MS detection. A Japanese quality control sample for APM (AS-1, 92
μg g−1 Sb) and an APM sample collected in Tokyo (APM
sample, 56 μg g−1 Sb) were investigated. In aqueous
extracts of APM sample and AS-1, apart from the major Sb(V)
species (ca. 80%), trimethylantimony species (TMSb) and several
hydride active unknown Sb species were for the first time detected.
TL;DR: The biomethylation of arsenic by the filamentous fungus Scopulariopsis brevicaulis was grown in media containing mixtures of arsenic and antimony compounds in various proportions, and the principle nonvolatile biometHylation products (trimethylantimony and trimethylarsenic species) in the medium were quantified by using HG-GC-AAS.
Abstract: The biomethylation of arsenic by the filamentous fungus Scopulariopsis brevicaulis is well documented, and the biomethylation of antimony by this fungus was recently established. However, in all the previous studies each metalloid was studied in isolation. Arsenic and antimony are often associated in the environment, and so an understanding of interactions between these elements is necessary. To this end, S. brevicaulis was grown in media containing mixtures of arsenic and antimony compounds in various proportions, and the principle nonvolatile biomethylation products (trimethylantimony and trimethylarsenic species) in the medium were quantified by using HG-GC-AAS. It was found that the yield of trimethylantimony compounds, obtained from the biomethylation of potassium antimony tartrate, was increased in the presence of sodium arsenite. The production of trimethylarsenic species from sodium arsenite was significantly inhibited in the presence of antimony (either as potassium antimony tartrate or antimony ...
TL;DR: A mixed-valent copper-antimony sulfide, [H2NCH2CH2NH2]0.5[Cu2SbS3], has been solvothermally synthesized from binary metal sulfides in the presence of ethylenediamine and characterised by single-crystal X-ray diffraction, thermogravimetry, elemental analysis and SQUID magnetometry as mentioned in this paper.
Abstract: A mixed-valent copper–antimony sulfide, [H2NCH2CH2NH2]0.5[Cu2SbS3], has been solvothermally synthesized from binary metal sulfides in the presence of ethylenediamine and characterised by single-crystal X-ray diffraction, thermogravimetry, elemental analysis and SQUID magnetometry. The structure of this material consists of chains of fused 5-membered rings of stoichiometry Cu2SbS3, linked into two-dimensional slabs of approximate thickness 5 A. Neutral ethylenediamine molecules reside between the slabs, to which they are hydrogen bonded. Magnetic susceptibility data yield an effective magnetic moment per formula unit of 0.94(6) μB, consistent with the presence of copper-(I) and -(II) species in the metal sulfide framework.
TL;DR: The condensation reaction of an overcrowded dihydrostibine with dibromobismuthine using 1,8-diazabicyclo[5.4.0]undec-7-ene as a base enabled the first stable stibabismuthene formation.
TL;DR: In this article, a series of back-coated cotton fabrics comprising varying molar ratios of chlorine, bromine and antimony has been studied using a simulated match ignition test, LOI and thermal analysis (TGA and DTA).
Abstract: A series of back-coated cotton fabrics comprising varying molar ratios of chlorine, bromine and antimony has been studied using a simulated match ignition test, LOI and thermal analysis (TGA and DTA).Results show that the presence of chlorine alone and in combination with bro mine increases LOI and carbonaceous char values at optimum halogen :anti mony molar ratios of 2.5-3.6:1 and bromine:chlorine molar ratios within the range 0.31-0.42. Only back-coated samples containing bromine pass the simu lated match test although at Br:Sb molar ratios above 4:1, LOI and char residual values decrease. It is evident that condensed and vapour phase flame retardant mechanisms are operating with efficiencies determined by halogen : Sb and Br/Cl molar ratios. Partial and whole replacement of halogen and antimony by phosphorus-containing and other flame retardants in the back-coating formulation that do not function in the vapour phase may be used to pass the simulated match test.
TL;DR: A microthermometric study using infrared microscopy was performed on fluid inclusions hosted in stibnite crystals of the Brouzils antimony deposit, in order to characterize the fluids responsible for the deposition of the antimony at the end of the Variscan metallogenic sequence as discussed by the authors.
Abstract: A microthermometric study using infrared microscopy was performed on fluid inclusions hosted in stibnite crystals of the Brouzils antimony deposit, in order to characterize the fluids responsible for the deposition of the antimony at the end of the Variscan metallogenic sequence. Primary fluid inclusions in stibnite were moderately saline (3.5–4.75 wt % NaCl equiv) with homogenization temperatures varying between 140° and 160°C. Two generations of later fluids are also contained in the stibnite samples. The first generation of secondary fluid inclusions is found exclusively in stibnite and is characterized by low salinities (1.35–2.2 wt % NaCl equiv), homogenization temperatures of approximately 215°C, and the presence of one or more solid mineral phases. The second generation of fluid inclusions is younger and is found in stibnite along secondary planes as well as in quartz gangue; it corresponds to H2O-CO2 fluid with homogenization temperatures of about 180°C. This infrared microscopy study thus shows that the quartz and stibnite of the Brouzils veins are not cogenetic and reveals the polyphase character of the vein infill in which three successive episodes of hydrothermal circulation are identified.
TL;DR: In this paper, a two-dimensional antimony sulfide was synthesized under hydrothermal conditions in the presence of N,N'-bis(3-aminopropyl)ethylenediamine and characterized by single-crystal X-ray diffraction, thermogravimetry and elemental analysis.
Abstract: A new two-dimensional antimony sulfide has been synthesized under hydrothermal conditions in the presence of N,N‘-bis(3-aminopropyl)ethylenediamine and characterized by single-crystal X-ray diffraction, thermogravimetry and elemental analysis. The product [C8N4H26]0.5[Sb7S11] (Mr = 1294.07) crystallizes in the triclinic space group, P1, with a = 5.9550(3) A, b = 14.567(1) A, c = 15.093(1) A, α = 68.448(4)°, β = 86.044(6)°, γ = 82.280(6)°, V = 1206 A3, and Z = 2. The structure consists of infinite chains of formula Sb7S112- linked through antimony−antimony bonds (2.921(2) A) into two-dimensional slabs of approximate thickness 2.6 A. These slabs contain pores of dimensions ca. 17.5 × 5.2 A, which are aligned along the [100] direction. N,N‘-Bis(3-aminopropyl)ethylenediamine cations reside between the slabs to which they are hydrogen bonded.
TL;DR: In this article, a procedure for the separation and determination of inorganic species of antimony based on the use of coupled high-performance liquid chromatography (HPLC) hydride generation (HG) atomic fluorescence spectrometry (AFS) is described.
Abstract: A procedure for the separation and determination of inorganic species of antimony based on the use of coupled high-performance liquid chromatography (HPLC) hydride generation (HG) atomic fluorescence spectrometry (AFS) is described. Sb(III) and Sb(V) were separated on a miniaturized anion-exchange column (Supelcosil LC-SAX 1, 2 cm × 4.6 mm id) using a 0.06 mol l−1 ammonium tartrate aqueous solution at pH 6.9 as eluent. The retention times were 0.45 and 3.5 min for Sb(V) and Sb(III), respectively. The hydrides were generated on-line with 3% m/v NaBH4 and 2 mol l−1 HNO3 aqueous solutions. The intensity of emission was linearly related to the concentration of the Sb(V) species in the range 1.0–50.0 µg l−1 (r2 = 0.9976) and of Sb(III) in the range 3.0–200 µg l−1, with detection limits of 0.8 and 1.9 µg l−1, for Sb(V) and Sb(III), respectively. The precision evaluated using the relative standard deviation (RSD) was 4.4 and 2.5% (n = 10) for Sb(V) and Sb(III) at concentrations of 10 µg l−1, respectively. The method has a sensitivity suitable for monitoring drinking and surface water according to the regulations established by the EU directives for antimony (10 µg l−1) and has been applied to the speciation of inorganic antimony in several spiked water samples.
TL;DR: In this paper, a simple and specific analytical method of determination of total inorganic antimony and antimony(V) in aqueous phase of the sample by inductively coupled plasma mass spectrometry (ICP-MS) was developed.
TL;DR: In this paper, X-ray absorption fine structure spectra (EXAFS) of antimony(V) solutions were obtained at temperatures from 25°C to 300°C at pressures corresponding to the liquid-vapour equilibrium curve for H2O.
Patent•
17 Oct 2000TL;DR: In this paper, a nonaqueous electrolyte for use in an electrochemical cell comprising at least one organic solvent, one electrolytically active salt represented by the formula: M'+m(ZRnXq-n)m in which: m' is selected from a group consisting of magnesium, calcium, aluminum, lithium, and sodium; Z is selected among a group of aluminum, boron, phosphorus, antimony and arsenic; R represents radical selected from the following groups: alkyl, alkenyl, aryl, phenyl
Abstract: The present invention provides a non-aqueous electrolyte for use in an electrochemical cell comprising: (a) at least one organic solvent; (b) at least one electrolytically active salt represented by the formula: M'+m(ZRnXq-n)m in which: M' is selected from a group consisting of magnesium, calcium, aluminum, lithium and sodium; Z is selected from a group consisting of aluminum, boron, phosphorus, antimony and arsenic; R represents radical selected from the following groups: alkyl, alkenyl, aryl, phenyl, benzyl, and amido; X is a halogen (I, Br, Cl, F); m=1-3; and n=0-5 and q=6 in the case of Z=phosphorus, antimony and arsenic, and n=0-3 and q=4 in the case of Z=aluminum and boron. Rechargeable, high energy density electrochemical cells containing an intercalation cathode, a metal anode, and an electrolyte of the above-described type are also disclosed.
TL;DR: In this paper, commercial antimony can be used directly for the allylation of carbonyl compounds in aqueous media in the presence of fluoride salts, which can be seen as an alternative to the use of antimony antimony for alloys.
TL;DR: It is shown that the dimethylantimony species is a true intermediate on the pathway to trimethylstibine (rather than arising from trimethylStibine oxidation or as an analytical artifact) because no dimethylantsimony species are formed on trimethylSTIBine oxidation, as determined by using HG-GC-AAS.
TL;DR: In this paper, a new method for the determination of species of antimony(III, V, SbV, and TMeSbO with fluoride as modifier is introduced.
TL;DR: In this paper, the effect of antimony/copper activators on cobalt removal and zinc dust consumption was investigated in a batch reactor using synthetic electrolyte at 95°C.
TL;DR: In this paper, antimony was extracted from environmental biota samples from Yellowknife, NWT and Meager Creek, BC, Canada using hydride generation-gas chromatography-atomic absorption spectrometry (HG-GC-AAS).
Abstract: Antimony was extracted from environmental biota samples from Yellowknife, NWT and Meager Creek, BC, Canada. Extraction efficiencies ranged from 0.7 to 37% for all samples except for a cattail sample, from which 95% of antimony was extracted. Speciation analysis was carried out by using hydride generation-gas chromatography-atomic absorption spectrometry (HG-GC-AAS). The major antimony species in all samples, including biota extracts and water, was Sb (V). Sb (III) and methylated antimony species were detected in some samples as well. The presence of methylated antimony species in moss from Yellowknife and a water sample from Yellowknife was confirmed by using HG-GC-AAS at a second absorption wavelength, increasing the likelihood that the peaks obtained are due to the presence of antimony compounds. A headspace HG-GC-mass spectrometric (MS) method was developed for the speciation of antimony compounds and this was used to successfully confirm methylantimony species in the headspace following HG of...
TL;DR: In this article, the structural and catalytic properties of nominal compositions VSb1−xTixO4 were studied by X-ray diffraction (XRD), Xray photo-electron spectroscopy (XPS), temperature programmed reduction (TPR), and the catalytic heterogeneous oxidation of toluene to benzaldehyde.
Abstract: Catalysts of nominal compositions VSb1−xTixO4, with x = 0, 0.1, 0.2 and 0.4, were prepared by solid state reaction of vanadium(V) oxide, antimony(III) oxide and titanium(IV) oxide mixtures. Their structural and catalytic properties were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (TPR) and catalytic heterogeneous oxidation of toluene to benzaldehyde. The samples with 10% (x = 0.1) and 20% (x = 0.2) of titanium present the highest activity and selectivity to benzaldehyde under the operating conditions used in this work. When the titanium content is 40% (x = 0.4), the activity level drops strongly below the level found for the undoped vanadium antimonate. X-ray patterns show the presence of vanadium(V) oxide as a separate phase in this sample, and this is probably the cause of the low catalytic performance. TPR results show that the replacement of antimony by titanium changes the oxidation-reduction properties of the vanadium antimonate phase. In the samples with titanium content up to 20%, there seems to be a direct relationship between the selectivity and the separation of the reduction temperatures of both reduction peaks of the TPR profile: the larger the separation, the higher is the selectivity to benzaldehyde. All the samples with x = 0, 0.1 and 0.2 show surface antimony excess despite being prepared from stoichiometric mixtures of nominal V/Sb ratios larger than or equal to 1.
TL;DR: The proposed method was applied to cell extracts of Leishmania donovani, which were incubated with antimony(III) and antimony (V) and some metabolism seemed to occur within the cells.
Abstract: An analytical method for the separation and quantification of Sb(III) and Sb(V) using anion chromatography with ICP-MS is presented. The optimum conditions for the separation of the antimony species were established with 15 mmol/L nitric acid at pH 6 as eluent system on a PRP-X100 column. The retention times for antimony(V) and antimony(III) were 85 s and 300 s with detection limits of 0.06 μg/L and 0.29 μg/L, respectively. The proposed method was applied to cell extracts of Leishmania donovani, which were incubated with antimony(III) and antimony(V). Some metabolism seemed to occur within the cells.