bluuebunny/crossref_metadata_2025_split huggingface dataset:
Speciation of organotin compounds by tandem mass spectrometry
Authors: Lawson G , Ostah N 
Published: January 2005

AbstractThe collison‐induced dissociation of a range of organotin compounds has been examined by tandem (MS–MS) mass spectrometry in order to investigate the potential of the technique for speciation without prior chromatographic separation. Tables of parent–daughte ion relationships are prepared for a group of six closely related compounds. The results obtained are sufficiently characteristic to distinguish between the isolated compounds and to identify the individual components of a simple mixture. This procedure has potential applications for less volatile compounds and for quantitative analysis.
Catalysis of hydrosilylation, part XXII: Polymer‐protected immobilized platinum complex catalysts for gas‐phase hydrosilylation of acetylene
Authors: Marciniec Bogdan , Foltynowicz Zenon , Lewandowski Mariusz 
Published: January 2005

AbstractA platinum catalyst (hexachloroplatinic acid dissolved in ethanol) was immobilized by anchoring via amine and mercapto groups to silica followed by formation of a polymer layer which protected the catalyst against leaching. These catalysts (A and B) as well as precatalysts (SA‐Pt, SB‐Pt) which were not protected by polymer were tested in the gas‐phase hydrosilylation reaction of acetylene with trichlorosilane.The catalytic parameters (yield 80%, selectivity 100%) obtained under optimal conditions prove the advantage of catalyst A over 300 h reaction time by the flow method.
Semi‐empirical MNDO study of the structure of some diorganotin (IV) glycylglycinates
Authors: La Manna Gianfranco , Ruisi Giuseppe , Barbieri Renato , Huber Friedo 
Published: January 2005

AbstractThe geometrical structures of some diorganotin glycylglycinates have been obtained using the MNDO semi‐empirical method. A good agreement with the experimental diffractometric data was found.
Seasonality in estuarine sources of methylated arsenic
Authors: Millward G E , Ebdon L , Walton A P 
Published: January 2005

AbstractThe effect of seasonal temperature change on the release of methylated arsenic from macroalgae, phytoplankton and sediment porewaters has been investigated by a series of controlled laboratory experiments. The appearance of dissolved arsenic species in the overlying waters was monitored using a coupled hydride generation/GC AA analytical technique. The liberation of dissolved arsenic species by the macroalgae Ascophyllum nodosum was examined under estuarine conditions at 5 °C and 15 °C. At the lower temperature the release rates were 0.2 μg kg−1 h−1 (wet weight of material) for monomethylarsenic (MMA) and 0.5 μg kg−1 h−1 for dimethylarsenic (DMA), whereas at 15 °C the rates were 0.4 μg kg−1 h−1 and 3.2 μg kg−1h−1, respectively. Incubation experiments were also carried out at 15 °C using the diatom Skeletonema costatum. During the log growth phase, when chlorophyll a concentrations were in the range 1‐5 μg dm−3, the rate of appearance of DMA in the water was ∼3 ng dm−3 h−1. Sediment samples from the freshwater and seawater end‐members of the Tamar Estuary, UK, were incubated under natural conditions at 5 °C and 15 °C. The freshwater sediments released DMA in preference to MMA; the concentrations of both species increased exponentially and reached a steady state in the overlying water after 250 h. Considerably more DMA was produced at 15 °C than at 5 °C, whilst the amount of MMA produced appeared to be insensitive to the temperature increase. In contrast, the seawater sediments always produced more MMA than DMA and the increase in temperature had little effect on the production of either MMA or DMA.The results of the laboratory experiments were compared with field observations in temperate estuaries, including the Tamar Estuary. The implications of changes of water temperature on the fate of arsenic in estuaries is discussed and modifications to the estuarine arsenic cycle are proposed.
Enhanced detection levels in the GC MS analysis of organometallic compounds, based on pre‐ and post‐acquisition data manipulation
Authors: Lawson G , Ostah N 
Published: January 2005

AbstractThe different modes of data acquisition utilized in GC MS analyses of organometallic compounds are discussed. Comparisons of detection limits for each operating mode are reported and a lower detection limit of ca 5pg organotin compound injected onto the column was determined. Mass spectral data for a range of organotin compounds are presented to facilitate the choice of species suitable for single (selected) ion monitoring (SIM)
The effect of unsaturation on the reaction of aqueous alkyl bromides with brass foil
Authors: Thayer John S 
Published: January 2005

AbstractBrass (a zinc/copper alloy) foil reacts with mixtures of water and alkyl bromides to give dissolution of zinc and copper. The relative rates of leaching depend on the bromide used: saturated bromides favor dissolution of zinc, whereas unsaturated bromides favor dissolution of copper. This difference is attributed to the formation of π‐complexes between the unsaturated linkages and the copper atoms.
The fate of triorganotin biocides on incorporation into hypalon paint‐based marine antifouling systems:119mSn Mössbauer and 119Sn NMR studies
Authors: Allen D W , Brooks J S , Campbell S J 
Published: January 2005

AbstractIncorporation of bis(tributyltin) oxide into a Hypalon paint system results in the formation of tributyltin chloride and a second organotin species, the identity of which remains uncertain. Both compounds are appreciably retained by the dried paint matrix, thereby resulting in marked reduction in the release rate of the tributyltin moiety into aqueous systems. In contrast, tributyltin acetate, tributyltin carbonate and bis(triphenyltin) oxide appear to be incorporated into the paint film in a largely unchanged state. In the case of triphenyltin chloride and triphenyltin acetate, evidence of dephenylation to form diphenyl‐ and monophenyl‐tin compounds has been obtained.
Metathesis of silicon‐containing olefins: IX. Synthesis of 1‐(trimethylsilyl)‐1‐alkenes by olefin metathesis
Authors: Foltynowicz Zenon , Pietraszuk Cezary , Marciniec Bogdan 
Published: January 2005

Abstract1‐(Trimethylsilyl)‐1‐alkenes of general formula CH3(CH2)nCHCHSi(CH3)3, where n = 3–15, have been prepared by a novel method, viz. by an effective cross‐metathesis of vinyltrimethylsilane with 1‐alkenes catalyzed by RuCl2(PPh3)3. Excess of 1‐alkene in the reaction mixture gave 1‐(trimethylsilyl)‐1‐alkenes in good yields of up to 60% (in terms of vinylsilane). The products were identified by NMR spectroscopic (1H, 13C NMR) and GC MS methods.
Ethylation of methylarsenic(III) compounds by sodium tetraethylborate
Authors: Clamagirand Vincent , Marr lain L , Wardell James L 
Published: January 2005

AbstractThe compounds MeAsBr2 and Me2AsBr at concentrations of (1–5) × 10−3 M in acetone solution are ethylated in high yield by NaBEt4 to MeEt2As and Me2EtAs, as shown by 1H NMR spectroscopy. The extents of ethylation of MeAs2+ and Me2As+ (expressed as ions, by convention) in aqueous acid solutions [at concentrations of (5–20) × 10−6 M] were investigated using cold trap/AA and GC AA procedures. The species Me2As+ was ethylated (to give Me2EtAs) in good yield (88%); in contrast, MeAs2+ produced the volatile trialkylarsine, MeEt2As, in poor yield (30%). No volatile trialkylarsine could be obtained on treating inorganic arsenic(III) (As3+) solutions with NaBEt4.
The use of sodium tetraethylborate in the derivatization of octyltin compounds
Authors: Craig Peter J. , Mennie Darren 
Published: January 2005

AbstractOctyltin trichloride (OctSnCl3) and dioctyltin dichloride (Oct2SnCl2) have been reacted with sodium tetraethylborate (NaBEt4) to yield the volatile tetraalkyltin derivatives OctSnEt3 and Oct2SnEt2. Single and mixed solutions of the octyltin chlorides have been derivatized, separated and quantified using interfaced GC AA and GC MS methodology.
Crystal structure and in vitro antitumour activity of dibutylbis(5‐chloro‐2‐hydroxybenzoato)tin(IV)
Authors: Gielen Marcel , Bouâclam Mohammed , Mahieu Bernard , Tiekink Edward R. T. 
Published: January 2005

AbstractThe crystal structure of the title compound, [nBu2Sn(5‐Cl‐2‐OH‐C6H3CO2)2], shows that in the monomeric species the six‐coordinate Sn atom exists in a skew trapezoidal bipyramidal geometry in which the four O donor atoms, derived from two asymmetrically chelating carboxylate ligands, define the basal plane and the n‐butyl substituents lie over the weaker SnO interactions defining a CSnC angle of 147.6(2)°. An unusual feature of the structure is the presence of both intra‐ and inter‐molecular hydrogen bonding contacts which serve to stabilize the structure. The in vitro antitumour activity of this compound against mammary and colon carcinoma cell lines is also reported.
Effects of GaAs and Ga2O3 on magnetometric behavior of iron oxide particles in rabbit lungs
Authors: Aizawa Yoshiharu , Takata Tsutomu , Karube Hitomi , Nakamura Ken , Kotani Makoto 
Published: January 2005

AbstractIntratracheal instillation of a GaAs suspension has been histopathologically shown to induce a diffuse pulmonary response. In the present study, magnetometry was used to evaluate the effects of intratracheally instilled GaAs and Ga2O3 on the behavior of externally magnetized iron oxide (Fe3O4) particles instilled in rabbit lung. Magnetometric evaluation of the effects of GaAs in rabbits dosed with 30 mg or 300 mg per animal showed a significantly decreased relaxation of iron oxide particles at 1, 3, 7, 14, 21 and 28 days following instillation compared with the controls. On the other hand, in the rabbits exposed to Ga2O3, significantly reduced decay constants were observed only on the first and third days following instillation.Relaxation indicates a rapid decrease of remanent magnetic field following magnetization of the lungs due to random rotation of phagocytosed iron oxide particles in macrophages.Clearance of the iron oxide particles was measured by serial determinations of the remanent magnetic field at the end of magnetization estimated from relaxation curves. Clearance was significantly impaired at 14, 21 and 28 days after instillation in rabbits exposed to both doses of GaAs. Slightly delayed clearance was also observed in rabbits exposed to Ga2O3.Histological examination of lungs instilled with GaAs indicated active phagocytosis of GaAs and iron oxide particles by pulmonary macrophages, as well as pneumonocytes hyperplasia with marked thickening of the alveolar walls. Minimal histological changes with retention of iron oxide particles were found in the lungs exposed to Ga2O3.
Different acute effects of oral and intratracheal administration of disodium arsenate and gallium arsenide on heme synthesis in rats
Authors: Kondo Masao , Ichikawa Isamu 
Published: January 2005

AbstractThe acute influences of arsenic compounds on the metabolism of porphyrins and heme in various organs of rats after oral or intratracheal administration of disodium arsenate (Na2HAsO4) and gallium arsenide (GaAs) were examined and compared.For the oral administration experiments, 21 or 84 mg of Na2HAsO4, or 2 or 4 g of GaAs, per cm3 saline per kg body weight of each animal was administered to Jcl: Wistar male rats and the organs were removed after exsanguination from the vein of the right axilla under anesthesia with ether, 16 h after administration. In the case of intratracheal administration, rats given 8.2 or 16.4 mg of Na2HAsO4, or 0.2 or 0.4 g GaAs per cm3 saline per kg body weight were examined under the same experimental conditions as for the administration route.Increase in the body weight of rats was suppressed after intratracheal administration of the two arsenic compounds. In these rats the hematocrit value increased significantly. These changes were not shown by the orally administered rats. Elevation in δ‐aminolevulinate synthase (ALA‐S, EC 2.3.1.37) activity in erythroblasts by Na2HAsO4 was much higher after intratracheal administration than after oral administration. Suppression in the activities of δ‐aminolevulinate dehydratase (ALA‐D, EC 4.2.1.24) and porphobilinogen deaminase (PBG‐D, EC 4.3.1.8) in peripheral erythrocytes by Na2HAsO4 and GaAs were stronger by intratracheal administration than by the oral route. Influences of GaAs on the activity of PBG‐D in rat liver were shown to be more effective by oral administration than by the intratracheal route. Oral administration of Na2HAsO4 and GaAs had a stronger suppression effect on the activities of ALA‐D and PBG‐D in rat kidney.It seems from these results that the different extents of the influence of arsenic compounds might depend on the routes of intake.
Effects of various elements on arsenic accumulation of the alga Dunaliella salina
Authors: Yamaoka Yukiho , Takimura Osamu , Fuse Hiroyuki 
Published: January 2005

AbstractThe effect of 23 various elements (nitrogen, manganese, magnesium, molybdenum, zinc, selenium, gallium, nickel, cobalt, lithium, strontium, vanadium, tin, antimony, bismuth, cadmium, chromium, lead, iron, silver, copper, potassium and calcium) in water on growth and arsenic accumulation in Dunaliella saline was investigated. The order of growth inhibition of D. salina by these elements was Ag>Cd>Co>Ni>Cu>Zn>Fe>Sb>Ga>Cr>Bi>Sr>Mn>Sn>Se>Pb>V>Ca, Mg, Mo, K, Li.Arsenic accumulation in D. salina was unaffected by an increase in calcium and chromium. Also, the arsenic content in D. salina decreased at a potassium concentration of 100 mg dm−3, and was also reduced by the addition of cadmium and nitrogen; however, it was increased by the addition of lithium at 100 mg dm−3, tin, gallium, bismuth, strontium, vanadium, iron and manganese at 10 mg md−3, lead, antimony, zinc, copper cobalt and nickel at 1 mg dm−3, selenium at 0.1 mg dm−3, and silver at 0.005 mg dm−3, respectively. These results imply that arsenic accumulation by D. salina depends upon biological activity and physical adsorption.
Comparisons of survival time estimates for niigata prefecture (japan) residents exposed to ingested arsenic
Authors: Tsuda Toshihide , Yamamoto Eiji , Babazono Akira , Mino Yoshio , Kishi Yoshiki , Kurumatani Norio , Ogawa Takanori , Aoyama Hideyasu 
Published: January 2005

AbstractSurvival analysis was used to analyze follow‐up data on an arsenic‐poisoned area, identified in 1959, in order to assess the effect of arsenic on survival time. The subjects were 443 residents of Namiki‐cho, Nakajo‐machi, Niigata Prefecture, Japan, who ingested well water contaminated with arsenic between 1955 and 1959. Their exposure to arsenic was only by ingestion of well water. We observed this historical cohort from October 1959 to February 1992. Survival time was calculated in two ways: from 1959 (the end of exposure) until death or until 1992 (the termination of follow‐up); or from birth until death or until 1992. The entire cohort was divided into two groups according to the arsenic concentration measured in the wells in 1959. Different survival curves of the two were drawn using the Kaplan–Meier method. The lifetime survival curves indicate that the lifetimes of arsenic‐exposed residents were significantly shorter than that of the low‐dose exposure group or of unexposed residents. From the differences in the estimated lifetime survival curves, the effect of arsenic on the mortality of the residents can be inferred.
Altered protein synthesis in rat kidney cells exposed to semiconductor materials
Authors: Aoki Yasunobu , Lipsky Michael M. , Fowler Bruce A. 
Published: January 2005

AbstractIt is thought that the extensive industrial use of arsenic, gallium and indium, which have applications as the materials for III–V semiconductors, will increase human exposure to these compounds in the near future. We have undertaken the development of new biological indicators for assessing exposure to these elements. Element‐specific alterations in protein synthesis patterns were expected to occur following exposure to arsenic compounds. We examined alterations in protein synthesis in primary cultures of rat kidney proximal tubule epithelial cells by sodium arsenite, gallium chloride and indium chloride, utilizing two‐dimensional gel electrophoresis. After incubation with the chemicals for 20 h, newly synthesized proteins were labeled with [35S]methionine. A protein with a molecular weight (Mr) of 30 000 was markedly induced on exposure to 10 μM arsenite or 300 μM gallium chloride, and synthesis of proteins with Mr values of 85 000, 71 000, 65 000, 51 000, 38 000 and 28 000 were also increased by exposure to arsenite and gallium chloride. No significant changes were observed upon exposure to indium. Some of these increased proteins could be heat‐shock proteins.
Effects of hijiki feeding on arsenic distribution in rats administered large doses of arsenate
Authors: Katayama Masayuki , Sugawa‐Katayama Yohko , Otsuki Kazuko 
Published: January 2005

AbstractMale rats fed a diet of 5% Hijiki seaweed or 5% cellulose for two weeks were administered large doses of sodium arsenate (Na2HAsO4) 7mg As kg−1 of body weight, during two days. At 48 h following the last arsenic administration, selected organs were isolated and homogenized. Femur and feces were lyophilized; portions of them were irradiated with thermal neutrons in a research nuclear reactor and their arsenic concentrations were determined from the induced gamma radiation from 76As. The greatest concentration of arsenic was detected in blood cells. A greater arsenic level was found in urine from the Hijiki diet group than in that of the cellulose diet group. The percentage distribution of arsenic in various organs indicated that the arsenic concentrated in blood cells 48 h after the arsenate administration, in comparison with the value 24 h after the arsenate administration [M. Katayama et al., Appl. Organomet. Chem. 6 389 (1992)]. The Hijiki diet accelerated arsenic accumulation in blood cells and the femur more than the cellulose diet, and arsenic levels in other organs (liver, heart, lung and kidney) of the Hijiki diet group decreased faster than those from the cellulose diet group.
Pulmonary toxicity of indium arsenide and arsenic selenide following repeated intratracheal instillations to the lungs of hamsters
Authors: Tanaka Akiyo , Hisanaga Akira , Hirata Miyuki , Omura Minoru , Inoue Naohide , Ishinishi Noburu 
Published: January 2005

AbstractChronic toxicity of indium arsenide (InAs) and arsenic selenide (As2Se3) was studied in male Syrian golden hamsters which received InAs or As2Se3 particles, each containing a total dose of 7.5 mg of arsenic, by intratracheal instillations once a week for 15 weeks. As a control, hamsters were treated with the vehicle, phosphate buffer solution. During their total lifespan, the cumulative body weight gain of the hamsters in the InAs group was suppressed significantly compared with that in the control group, but not in the As2Se3 group when compared with that in the control group. However, the survival rate for the InAs group was significantly higher compared with the control group, but not for the As2Se3 group when compared with the control group. During the animals' total lifespan, one lung adenoma was seen in the 27 hamsters in the InAs group and one lung adenoma in the 23 hamsters in the control group. No tumors of the lung were observed in the As2Se3 group. Malignant tumors outside the lung appeared in four hamsters in the InAs group and in two in the As2Se3 group. No non‐lung malignant tumours were seen in the control group. Total tumor incidence rates were 25.9% (7/27) in the InAs group, 10.3% (3/29) in the As2Se3 group and 8.7% (2/23) in the control group. There were therefore no significant differences in tumor incidence between the InAs or the As2Se3 group, and the control group.Regarding histopathological findings in the lung, incidence rates of proteinosis‐like lesions, pneumonia, metaplastic ossification and emphysema were seen only in the InAs group, and alveolar or bronchiolar cell hyperplasia observed in both the InAs and the As2Se3 groups were at significantly higher rates than those in the control group.From these results, it was concluded that InAs and As2Se3 particles could induce pulmonary toxicity when instilled intratracheally into hamsters. A great deal of attention should be paid to the toxicity of both InAs and As2Se3, even though in this study the adverse health effects of As2Se3 appeared to be less than those of InAs.
Biomethylation and biotransformation of arsenic in a freshwater food chain: Green alga (chlorella vulgaris)→shrimp (neocaridina denticulata)→killifish (oryzias iatipes)
Authors: Kuroiwa Takayoshi , Ohki Akira , Naka Kensuke , Maeda Shigeru 
Published: January 2005

AbstractTolerance, bioaccumulation, biotransformation and excretion of arsenic compounds by the fresh–water shrimp (Neocaridina denticulata) and the killifish (Oryzias latipes) (collected from the natural environment) were investigated. Tolerances (LC50) of the shrimp against disodium arsenate [abbreviated as As(V)], methylarsonic acid (MAA), dimethylarsinic acid (DMAA), and arsenobetaine (AB) were 1.5, 10, 40, and 150μg As ml−1, respectively.N. denticulata accumulated arsenic from an aqueous phase containing 1 μg As ml−1 of As(V), 10 μg As ml−1 of MAA, 30 μg As ml−1 of DMAA or 150 μg As ml−1 of AB, and biotransformed and excreted part of these species. Both methylation and demethylation of the arsenicals were observed in vivo. When living N. denticulata accumulating arsenic was transferred into an arsenic–free medium, a part of the accumulated arsenic was excreted. The concentration of methylated arsenicals relative to total arsenic was higher in the excrement than in the organism.Total arsenic accumulation in each species via food in the food chainGreen algae (Chlorella vulgaris)→ shrimp (N. denticulata)→ killifish (O. latipes)decreased by one order of magnitude or more, and the concentration of methylated arsenic relative to total arsenic accumulated increased successively with elevation in the trophic level. Only trace amounts of monomethylarsenic species were detected in the shrimp and fish tested. Dimethylarsenic species in alga and shrimp, and trimethylarsenic species in killifish, were the predominant methylated arsenic species, respectively.
Novel polymers containing carbon–anchored organotin groups
Authors: Seyferth Dietmar , Craig Masterman T. 
Published: January 2005

AbstractThree polymers containing Bu2SnX (X=OAc or Cl) groups linked to the polymer through a C–Sn bond have been prepared by hydrostannation (via Bu2Sn HCl) of the following CH=CH2h‐containing polymers: (1) a polybutadiene containing approx. 70% of 1,2 CH=CH2 units; (2) poly(allyl methacrylate); (3) poly(tetraethylene glycol monoallyl ether methacrylate). The first and third were tested for activity against a number of marine organisms and found to be inactive. Presumably this observed biological inactivity arises from the fact that R3Sn(H2O) ions are not released into the aqueous medium.