Arsenic Chloride Research Articles

Identification of Impurities in High-Pure Arsine by Chromatography–Mass-Spectrometry

A method of chromatography–mass spectrometry is used to study the impurity composition of arsine synthesized by the reaction of arsenic chloride with sodium borohydride. Capillary adsorption columns with adsorbents modified silica and polytrimethylsilylpropine is used for the separation of impurities. Impurities are identified by comparing their mass spectra with the NIST database, published data, as well as by reconstructing their structures from fragment ions. Impurities of permanent gases; saturated and unsaturated hydrocarbons C1–C6; chlorinated, oxygenated, and aromatic hydrocarbons; volatile inorganic hydrides; and alkyl derivatives of arsine, trimethyl fluorosilane, carbon sulfur dioxide, and dimethyl sulfide are identified in arsine. Mass spectra of C2H3AsH2, CH3AsHC2H5, and C2H5As2H3 impurities are obtained for the first time.

Permethylated Disila[2]metallocenophanes of Group 14 and 15 Elements.

Permethylated disila[2]metallocenophanes of silicon, germanium, tin, lead, 2 a-d, (tetrelocenophanes) and antimony, 3 a,b, (pnictogenocenophanes) are described. In the case of antimony, a chloro-substituted stibonocenophane, 3 a, as well as cationic stibonocenophanium tetrachloroaluminate and tetraphenylborate salts, 3 b[X] (X=[AlCl4 ], [BPh4 ]), were synthesized. These represent the first examples of metallocenophanes of any Group 15 element. All compounds were studied in solution and in the solid state. Without exception the ansa-bridge exerts a strong influence on the bending angle of the two Cp-ligands. For disila[2]plumbocenophane, 2 d, its reactivity towards Group 15 halides was probed. Treatment of disila[2]plumbocenophane, 2 d, with two equivalents of phosphorus(III) chloride or arsenic(III) chloride, results in a ring-opening reaction and gives the bis(dihalopnictogenyl)-substituted products, 4 a,b.

Insights into the effect of chlorine on arsenic release during MSW incineration: An on-line analysis and kinetic study

The effect of chlorine on arsenic (As) release dynamics during municipal solid waste (MSW) incineration in a fluidized bed was studied on the basis of an on-line analysis system. This system can continuously and quantitatively measure the concentrations of trace elements in flue gas. Chlorine addition increases obviously the concentration of arsenic in flue gas, indicating a promoting effect of chlorine on arsenic release during MSW incineration. Based on the temporal concentration of arsenic in flue gas, the overall kinetic parameters of arsenic release during MSW incineration were calculated. A second-order kinetic law r(x) = 81.6e−66.9/RT (−1.05x2 − 0.01x + 1.03) was ascertained for arsenic release during MSW incineration without chlorine addition, and r(x) = 177.3e−65.3/RT (−0.68x2 − 0.43x + 1.08) for arsenic release with chlorine addition. Thermodynamic calculations were performed to predict the partitioning behavior of arsenic during MSW incineration. The addition of chlorine can not only compete with gaseous arsenic to react with mineral, but is also able to increase the volatilization of arsenic by forming volatile arsenic chlorides, thereby affecting the release kinetics of arsenic during MSW incineration.

Arsenic Partitioning Behavior During Sludge Co-combustion: Thermodynamic Equilibrium Simulation

Using the computation method of thermodynamic equilibrium, effects of sewage sludge (SS) co-combustion conditions and interactions with Fe2O3, SiO2, CaO and Al2O3 on migration and transformation of arsenic (As) were simulated in oxy-fuel (CO2/O2) and air (N2/O2) atmospheres. Arsenic mainly existed as As(s), As4(g), As2O5(s), As4O6(g) and AsO(g) and volatilized more easily in reducing than oxidizing atmosphere. Increased O2 concentration slowed down the formation rate of AsO(g), thus reducing the volatilization rate of As. With the increased pressure, the conversion rate of As2O5(s) into As4O6(g) accelerated. In the multi-chemical system of SiO2, Al2O3 and CaO, As reacted with CaO and Al2O3 to form AlAsO4(s) and Ca3(AsO4)2(s) which inhibited As volatilization. SiO2 prevented As from reacting with CaO to generate Ca3(AsO4)2(s). Fe2O3 affected reactions between Al2O3(CaO) and As which inhibited As volatilization. In the whole SS co-combustion system, As reacted with O2 but had a weak affinity with Cl and with no arsenic chlorides observed.

Crystal structures and quantum chemical calculations of dichloro[4-(dimethylamino)phenyl]arsine and tris[4-(dimethylamino)phenyl]arsine

Dichloro[4-(dimethylamino)phenyl]arsine (1) and tris[4-(dimethylamino)phenyl]arsine (2) were synthesized and characterized using single crystal X-ray diffraction studies, NMR spectroscopy, IR spectroscopy and elemental analyses techniques. The X-ray structure analysis of 1 (P1¯, triclinic, Z = 4; R1 = 0.0478) revealed two crystallographically independent molecules in the asymmetric part of the unit cell. The average AsCl bond (220.6 p.m.) is found to be slightly longer than that of arsenic(III) chloride (216.1 or 216.2 p.m.), but to be rather similar to that in the orthorhombic modification of chlorobis[2,4,6-tris(trifluoromethyl)phenyl]arsine (219.2 p.m.). Mean As–Caryl (191.7 p.m.) and Caryl–N bond lengths (135.9 p.m.) suggest extended electronic interactions between the dichloroarsanyl group, the π-electron system of the arene ring and the nitrogen lone pair. In both molecules the nitrogen atoms are found in a planar coordination sphere; the sums of bond angles vary only slightly between 359.1° for 1a and 359.9° for 1b. In contrast to these observations, sums of bond angles of 292.7° for 1a and 293.98° for 1b indicate a pyramidal coordination sphere at arsenic. As well, the X-ray structure analysis of 2 (P1¯, triclinic, Z = 2; R1 = 0.0347) reveals bond lengths and angles at arsenic (AsC 194.9 p.m., CAsC 99.3°, AsCC 121.3°) as to be expected and obtained for similar compounds such as triphenyl arsine or triphenyl arsine derivatives. The sums of angles at two of the nitrogen atoms amount to values of 353.6° and 356.1° and deviate significantly from the value of the third (348.1°). Hence, two of three dimethylamino groups are found to be almost planar, whereas the third group shows a coordination sphere which has to be classified as an intermediate between trigonal planar and trigonal pyramidal. The molecule shows a high degree of C3 pseudosymmetry; the sum of angles at arsenic amounts to 298.0°. The average Caryl–N bond length (139.0 p.m.) suggests an interaction of the nitrogen lone pair with the π-system of the arene ring but it turns out to be much weaker than in dichloro[4-(dimethylamino)phenyl]arsine (1). Additionally, quantum chemical calculations were performed on several para substituted dichlorophenyl arsine compounds in order to ascertain optimized structural data and to shed some light onto these phenomena. Indeed, the aforementioned shortening of the N–Cipso bond to 135.9 p.m. can only in part be attributed to the well-known electronic interaction between the lone pair at nitrogen and the antibonding π∗ orbitals of the adjacent Cipso–Cortho bonds – on an average, these two distances are significantly elongated by 1.7 p.m. with respect to the standard value (140 p.m.).

Synthesis, crystal structures, and quantum chemical calculations of trialkyl-substituted 1λ3,3λ3,5λ3-triphospha dewarbenzenes

This work has involved the reaction of kinetically stable 2-tert-buty-lλ3-phospha-alkyne, tBu–CP, with dichloro(dialkylamino)arsines, in which the isolated products were characterized by spectroscopic methods; additionally, the results of X-ray structure analyses were confirmed by quantum chemical calculations using Gaussian 98 molecular modeling software. The arsenic component of the starting material is completely lost, probably as a precipitate of insoluble “arsenic(I) chloride,” and unusual oligocycle 2,4,6-tri-tert-butyl-3-chloro-1-dialkylamino-1λ5σ4,3λ3σ3,5λ3σ2-triphosphabicyclo[2.2.0]hexa-1,5-diene (1) – an ylide with an unusually long P–Cl bond (245.5 p.m.) – could be isolated. From these reactions, compounds 1a to 1d differing by their substituents at nitrogen were isolated as deep red, cuboid-shaped single crystals. X-ray structure analyses reveal molecules which are characterized by an ylidic and a regular P–C double bond of almost equal length [P1⊕–C2⊖av.172.2 p.m., P5–C6av.169.6 p.m.]. In addition to these two characteristic features the average bond length P3–C2 is found to be considerably shortened to a value of 172.7 p.m., whereas the adjacent phosphorus–chlorine bond P3–Cl1 is strongly elongated to 245.5 p.m.

Worldwide contamination of water by fluoride

Fluoride contamination in water is a major problem across the globe, with health hazards such as dental and skeletal fluorosis. Most earlier studies are confined to local or regional scales. As the problem has serious socioeconomic implications, there is a need for a global perspective. Thus, here we review worldwide research for nearly a century on fluoride contamination in water. We investigated the distribution of fluoride contamination in water, its sources, mobilization and association. The major findings are: (1) Anomalous fluoride concentration in groundwater is mainly confined to arid and semiarid regions of Asia and North Africa. (2) The geogenic sources of fluoride in water are mainly fluorine-bearing minerals in rocks and sediments, whereas anthropogenic sources of fluoride in water are mainly pesticides and industrial waste. (3) Fluoride mobilization from geogenic sources is mainly controlled by alkalinity and temperature. (4) Fluoride occurrence in water is associated with ions such as sodium, arsenic chloride and bicarbonate. There are few associations of fluoride in water with calcium and magnesium.

Surface Chemistry of III-V Semiconductors After Wet Etching with HCl and H2O2

GaAs(100) was immersed in water and aqueous mixtures of isopropyl alcohol, ethylene glycol, acetic acid, glycolic acid, tartaric acid, and HCl with and without the addition of H2O2 to understand the etching mechanism. The surface composition after etching was characterized using x-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Ga and As oxides with high oxidation states dissolve in water, but acids are needed to remove the oxides with low oxidation states. H2O2 oxidized the bulk substrate, and only the acids that have pKa values lower than 4 supported etching. After etching with HCl, the surface is terminated by arsenic chloride (As-Cl).

Arsenic(III) chloride ammonolysis

A systematic study into the scheme of reaction of ammonia with arsenic(III) chloride has been carried out using advanced quantum-chemical methods QCISD(T), B3LYP, MP2, CBS-QB3, and G2. Cl2AsNH2, ClAs(NH2)2, and As(NH2)3 can act as intermediates in the course of consecutive amination of AsCl3. The activation energy of these stages does not exceed 11 kcal/mol. The formation of an ammonium chloride salt appreciably increases the exothermicity of the reaction.

Hepatorenal Protective Activities of Plantain Root (Musa paradisiaca) on Arsenic-induced Oxidative Damage in Rat

The protective role of aqueous root extract of Musa paradisiaca on arsenic chloride-induced oxidative damage in the liver and kidney of albino rats was investigated in this study. Twenty four albino rats were grouped in to four (A, B, C and D). Group A served as the control and received distilled water while B, C and D were administered 10 mg/kg bw of arsenic chloride weekly. Groups C and D were treated with 200 and 500 mg/kg bw of aqueous extract of Musa paradisiaca roots respectively for 28 days while group B was left untreated. Phytochemical screening carried out on the root powder indicated the presence of tannins, terpenoids, steroids, sarponins, cardiac glycosides and flavonoids. Arsenic chloride induced a significant elevation in aminotransferases (ALT and AST), ALP and total bilirubin and reduction in serum protein and albumin indicating derangement of liver function. Significant elevation of serum creatinine, urea, uric acid, blood urea nitrogen and electrolytes levels were also recorded in arsenic intoxicated rats indicating disruption of kidney function. Histological examination of the kidney and liver of arsenic intoxicated rats also indicated significant alteration in tissue architecture and morphology. There was significant increase in the liver and kidney weight index in arsenic treated groups compared to the control indicating tissue inflammation. Treatment of rats with different doses of Musa paradisiaca root extract significantly (P<0.05) normalized liver and kidney functions while it also restored normal tissue histology at the end of the experiment. It can be concluded that Musa paradisiaca contain bioactive constituents capable of protecting the living system against arsenic-induced disruption of liver and kidney functions in rats.

Ethotoxicological Role of Melatonin as an Anti-Stressor Agent in Heavy Metal Intoxicated Fish Channa punctatus

Sublethal effects of arsenic trioxide, cadmium chloride, lead nitrate and mercuric chloride, were investigated on chromatophore morphology and behaviour of Channa punctatus. The protective role of melatonin was investigated. Changes were observed in the chromatophore pattern of fish scales and in fish behaviour after administration of the heavy metals. Heavy metal exposure caused restlessness in fishes and increased the dispersal of pigments in the chromatophores. Melatonin administration counteracted both these effects. The melatonin treatment did not modify metal concentration in scales, but it caused the aggregation of pigments in chromatophores of the fish. It also reduced the aggression observed in the fishes caused by the heavy metal administration. Toxicopathological alterations include statistically significant variations in the number, size and shape of the melanophores. The heavy metal-induced morphological changes in the melanophores indicate protective role against toxic insult of heavy metals.

Mapping Contaminants Associated with Autism: A Public Health Pilot in New Jersey

The rise in reported prevalence rates of autism spectrum disorders (ASDs) is a national concern that continues to grow at a record pace. New Jersey has the highest prevalence rate of autism spectrum disorders (ASDs) among states surveyed, with approximately 1 in 45 children diagnosed. The pilot study focused on toxins potentially linked to autism: arsenic, lead, manganese, mercury, organophosphate pesticides, polychlorinated biphenyls, trichloroethylene, and vinyl chloride. In northern NJ there were approximately 4600 Known Contaminated Sites (KCSNJ) where these toxins were detected. A total of 269,790 sample detections were identified. Our objective was to identify and map these sites, and identify methods by which more robust contaminant data could be collected and analyzed. This study resulted in eight original maps showing sample detections. These maps will aid researchers and public health advocates in future analyses exploring links between autism and these toxins. Concentrations of multiple toxins associated with ASDs were most dense near urban industrial or mixed residential/industrial areas, though no conclusions can be made regarding association or causality between the sample detections and autism. Based in part on this study, NJDEP has made and will continue to make improvements to contaminant data collection systems.

Application of advanced oxidation processes for cleaning of industrial water generated in wet dedusting of shaft furnace gases

The paper presents results of studies into advanced oxidation processes in O3 and O3/UV systems. An advanced oxidation process (AOP) was conducted to reduce the load of impurities in circulating waters from wet de-dusting of shaft furnace gases. Besides inorganic impurities, i.e. mainly arsenic compounds (16 g As L−1 on average), lead, zinc, chlorides and sulphates, the waters also contain some organic material. The organic material is composed of a complex mixture that contains, amongst others, aliphatic compounds, phenol and its derivatives, pyridine bases, including pyridine, and its derivatives. The test results show degradation of organic and inorganic compounds during ozonation and photo-oxidation processes. Analysis of the solutions from the processes demonstrated that the complex organic material in the industrial water was oxidized in ozonation and in photo-oxidation, which resulted in formation of aldehydes and carboxylic acids. Kinetic degradation of selected pollutants is presented. Obtained results indicated that the O3/UV process is more effective in degradation of organic matter than ozonation. Depending on the process type, precipitation of the solid phase was observed. The efficiency of solid-phase formation was higher in photo-oxidation with ozone. It was found that the precipitated solid phase is composed mainly of arsenic, iron and oxygen.

SXPS study of model GaAs(100)/electrolyte interface

AbstractModel GaAs(100)/electrolyte interfaces are prepared in vacuum by co‐adsorption of Cl2 and 2‐propanol molecules at LN2 temperature. On adsorption of Cl2 molecules gallium chlorides, elemental arsenic and arsenic chlorides are formed. Co‐adsorption of 2‐propanol causes formation of additional GaCl3 and AsCl, as well as soluble/volatile As‐based complexes, which are released from the surface depleting the sur‐ face by arsenic. Comparison of the As 3d and Ga 3d spectra obtained after heating the model interface to room temperature with the corresponding spectra obtained after emersion of the GaAs(100) surface from HCl/2‐propanol solution allows to conclude that in HCl solution Cl– ions attack gallium sites and H+ ions mostly attack arsenic sites. (© 2010 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Cytological effect of heavy metals on root meristem cells of Vicia faba L.

The effects of mercuric acetate, arsenic chloride, cadmium chloride, and copper acetate on cell division and chromosomal morphology of Vicia faba were studied. The results showed that heavy metals (1) are mitodepressive in higher concentrations, (2) act as mitopromotors at lower concentrations, and (3) induced a variety of chromosomal abnormalities such as adherence, chromatid separation, disturbed metaphase, C-mitosis, precocious movement of chromosomes, laggards, bridges, and fragments. In recovery, the mitotic index was improved, but less than that found in controls. The results demonstrated a clastogenic effect for the heavy metals.

1,4-Dihydro-1,4-diarsinine: Facile Synthesis via Nonvolatile Arsenic Intermediates by Radical Reactions

Novel cyclic organodiarsenic compounds, 1,4-dihydro-1,4-diarsinines, were synthesized by radical reactions of pentamethylcyclopentaarsine (1) and acetylenic compounds. The radical reactions of 1 and acetylenic compounds such as dimethyl acetylenedicarboxylate (2a) and 4-ethynylpyridine (2b) in refluxing benzene with 2,2‘-azobis(isobutyronitrile) (AIBN; 5 mol %) under a nitrogen atmosphere provided the corresponding 1,4-dihydro-1,4-diarsinines (3). Formation of 1,4-dihydro-1,4-diarsinine was confirmed by 1H and 13C NMR spectra and FAB-mass spectrometry. The structures of 3 were confirmed as cis(e,e) forms by X-ray crystallography. This is a facile synthesis of cyclic organodiarsenic compounds, in which no volatile toxic intermediates such as arsenic chlorides and arsenic hydrides were used. Moreover, this is the first example of the synthesis of 1,4-dihydro-1,4-diarsinines.

Nucleolin links to arsenic-induced stabilization of GADD45 mRNA

The present study shows that arsenic induces GADD45α (growth arrest and DNA damage inducible gene 45α) mainly through post-transcriptional mechanism. Treatment of the human bronchial epithelial cell line, BEAS-2B, with arsenic(III) chloride (As3+) resulted in a significant increase in GADD45α protein and mRNA. However, As3+ only exhibited a marginal effect on the transcription of the GADD45α gene. The accumulation of GADD45α mRNA is largely achieved by the stabilization of GADD45α mRNA in the cellular response to As3+. As3+ is able to induce binding of mRNA stabilizing proteins, nucleolin and less potently, HuR, to the GADD45α mRNA. Although As3+ was unable to affect the expression of nucleolin, treatment of the cells with As3+ resulted in re-distribution of nucleolin from nucleoli to nucleoplasm. Silencing of the nucleolin mRNA by RNA interference reversed As3+-induced stabilization of the GADD45α mRNA and accumulation of the GADD45α protein. Stabilization of GADD45α mRNA, thus, represents a novel mechanism contributing to the production of GADD45α and cell cycle arrest in response to As3+.

In Vitro Penetration of Pig Skin by Heavy Metals in Soil

The potential health risk from exposure to heavy metal contaminated soil is often based on the quantity of metal that can be removed from soil by vigorous extraction procedures. This approach can overestimate risk since it ignores complex interactions between metals and soil that can result in a reduction in the amount of metal that desorbs from soil and is subsequently absorbed by the body. The aim of this research was to determine the relative contribution of the soil matrix and heavy metal sequestration in soil with time (“aging”) on the dermal penetration of arsenic, mercury, and nickel, respectively, as arsenic acid, mercuric chloride, and nickel chloride. In vitro flow-through diffusion cell studies were performed utilizing dermatomed male pig skin and radioactive compounds to measure total penetration (the sum of each metal in receptor fluid and skin). For arsenic and nickel, the soil matrix produced a 78–87% reduction in dermal penetration compared to 12–19% after aging. A greater effect was observed with aged mercury (52–56% decrease in dermal penetration) than in freshly spiked soil (40–43%). The results indicate that the potential health risk from dermal exposure to the metals can be significantly reduced by soil and aging.

Synthetic and Spectroscopic Studies on Some Bis(dialkyldithiocarbomato)-arsenic(III) O,O'-dialkyldithiophosphates

The reactions of bis(dialkyldithiocarbamato)arsenic(III) chloride with sodium salts of dialkyldithiophosphates in 1:1 molar ratio give the corresponding mixed derivatives of the type [R2NCS2]2AsS2P(OR′)2 [where, R = CH3 and C2H5; R′ = Et, Pr n , Pr i , Bu n and Bu i ]. These derivatives are yellow crystalline solids or yellow viscous liquids. All these newly synthesized derivatives are soluble in common organic solvents such as benzene, chloroform, carbondisulphide, acetone, and dichloromethane. These derivatives have been characterized by melting points (only solid derivatives), elemental analysis (C, H, N, S, and As) as well as spectral IR, NMR [1H, 13C, and 31P] studies. Based on these studies tentative structures for these derivatives have been proposed.

Organic and inorganic arsenic speciation through ion exchange chromatography with particle beam-glow discharge mass spectrometry detection

A mixture of organic and inorganic arsenic compounds has been separated using ion exchange liquid chromatography and detected using a particle beam glow discharge mass spectrometer (PB-GDMS). The particle beam interface makes use of nebulization and momentum separation to deliver a stream of dry analyte particles to the glow discharge source from the LC output. In the glow discharge, the analyte particles are vaporized and ionized at or near the cathode surface. The ions are analyzed by a quadrupole mass spectrometer collecting data in either single ion monitoring (SIM) or total ion counting (TIC) modes. The separation of arsenobetaine (2-(trimethylarsonio)acetate), arsenic(III) chloride and dimethylarsenic acid was performed on a universal cation-exchange column using an isocratic mobile phase, with a total elution time of less than four minutes. The mass spectrum for each of these compounds contains a strong elemental arsenic signal as well as the molecular fragments that allow for the identification of the specific species responsible for the chromatographic peak. The limits of detection (LOD) for organic arsenic (dimethylarsenic acid) were found to be 2 ppm (90 ng DMA molecular ion) in the TIC mode and 15 ppb (0.8 ng As from DMA) in the SIM mode. Inorganic arsenic(III) chloride has an LOD of 11 ppb or 0.55 ng As absolute. This work suggests that the PB-GDMS has high potential as a comprehensive (inorganic/organic) detector for both biological and environmental speciation work.