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Organotin Compounds (organotin + compound)
Selected AbstractsStructural Diversity in Organotin Compounds Derived from Bulky Monoaryl Phosphates: Dimeric, Tetrameric, and Polymeric Tin Phosphate ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2008Ramaswamy Murugavel Abstract Monoaryl phosphates with a bulky aryl substituent have been used to synthesize new organotin clusters and polymers. The equimolar reaction between 2,6-diisopropylphenylphosphate (dipp-H2) and Me2SnCl2 in ethanol at 25 °C leads to the formation of [Me2Sn(,3 -dipp)]n (1), while the reaction of 2,6-dimethylphenylphosphate (dmpp-H2) with Me2SnCl2 in either a 1:1 or 2:1 molar ratio proceeds to produce exclusively [Me2Sn(,-dmpp-H)2]n·nH2O (2). Compounds 1 and 2 are 1D polymers with different architectures. In compound 1, the tin atom is five-coordinate (trigonal bipyramidal). Each dipp ligand bridges three different tin atoms to form an infinite ladder-chain structure. In 2, each six-coordinate (octahedral) tin atom is surrounded by four phosphate oxygen atoms originating from four different bridging dmpp-H ligands, thus forming a spirocyclic coordination polymeric chain. The use of nBu2SnO as the diorganotin source in its reaction with dipp-H2 leads to the isolation of dimeric [nBu2Sn(,-dipp-H)(dipp-H)]2 (4), which contains a central Sn2O4P2 unit. There are two chemically different half molecules of 4 in the asymmetric part of the unit cell and hence it actually exists as a 1:1 mixture of [nBu2Sn(,-dipp-H)(dipp-H)]2 and [nBu2Sn(,-dipp)(dipp-H2)]2 in the solid state. The reaction of the monoorgano tin precursor nBuSn(O)(OH)·xH2O with dipp-H2 takes place in acetone at room temperature to yield the tetrameric cluster 5, which has different structures in the solution and in the solid state. 31P NMR spectroscopy clearly suggests that 5 has the formula [nBu4Sn4(,-O)2(,-dipp-H)8] in solution. The single-crystal X-ray diffraction studies in the solid state, however, reveal that compound 5 exists as [nBu4Sn4(,-OH)2(,-dipp-H)6(,-dipp)2]. The use of compounds 1,4 as possible precursors for the preparation of ceramic tin phosphate materials has been investigated. The thermolysis of 1 at 500 °C leads to the formation of quantitative amounts of Sn2P2O7, while the thermolysis of 2, 3, and 4 under similar conditions results in the formation of SnP2O7. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] ChemInform Abstract: Efficient Oxidation of 1,2-Diols into ,-Hydroxyketones Catalyzed by Organotin Compounds.CHEMINFORM, Issue 39 2009Toshihide Maki Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] One-dimensional Infinite Chain Organotin Compounds: Synthesis and Structural Characterization of Triphenyltin Thiazole-2-carboxylate and Triphenyltin 3-PyridinylcarboxylateCHINESE JOURNAL OF CHEMISTRY, Issue 10 2002Han-Dong Yin Abstract Triphenyltin thiazole-2-carboxylate (1) and triphenyltin 3-pyridinylcarboxylate (2) were synthesized by the reaction of sodium thiazole-2-carboxylate or sodium 3-pyridinylcarboxylate with the triphenyltin chloride and their crystal structures were determined by single crystal X-ray diffraction analysis. In the structure of 1, the tin atom is five-coordinated in a distorted trigonal bipyramidal structure. Due to the presence of a close intermolecular Sn,S interaction distance of 0.3666 nm, the structure can be described as a weakly-bridged one-dimensional chain compound. In the structure of 2, the tin atom is five-coordinated with bridging 3-pyridinylcarboxylate ligands N atom and resulting structure is one-dimensional chain compound. [source] Effect of tributyltin on testicular development in Sebastiscus marmoratus and the mechanism involved,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2009Jiliang Zhang Abstract Organotin compounds, such as tributyltin (TBT), that have been used as antifouling biocides can induce masculinization in female mollusks. However, few studies addressing the effects of TBT on fishes have been reported. The present study was conducted to investigate the effects of TBT at environmentally relevant concentrations (1,10, and 100 ng/L) on testicular development in Sebastiscus marmoratus and to gain insight into its mechanism of action. After exposure for 48 d, the gonadosomatic index had decreased in a dose-dependent manner. Although the testosterone levels in the testes were elevated and the 17,-estradiol levels were decreased, spermatogenesis was suppressed. Moreover, ,-glutamyl transpeptidase activity (which is used as a Sertoli cell marker) was decreased in a dose-dependent manner after TBT exposure, and serious interstitial fibrosis was observed in the interlobular septa of the testes in the 100 ng/L TBT test group. Increases in the retinoid × receptors and peroxisome proliferator activated receptor , expression and the progressive enlargement of lipid droplets in the testes were observed after TBT exposure. Estrogen receptor , levels in the testes of the fish exposed to TBT decreased in a dose-dependent manner. The reduction of estrogen receptor , mRNA resulted from the decrease of 17,-estradiol levels, and the progressive enlargement of lipid droplets may have contributed to the dysfunction of the Sertoli cells, which then disrupted spermatogenesis. [source] Kinetic monitoring of trisubstituted organotins in soil after sewage sludge applicationAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2008S. Dubascoux Abstract Organotin compounds (OTC) are widely used for their biocidal effects in various agricultural or industrial activities, leading to their environmental presence. Among the organotin species, tributyltin (TBT) and triphenyltin (TPhT) are the most used and are generally considered the most toxic. So it is important to understand their behaviour in soils and obtain data about their persistence and phytoavailability. Many works deal with OTC speciation in various matrices, but few are concerned with OTC degradation in soil. The present study focuses on kinetic monitoring of TBT and TPhT in an agricultural soil. These compounds were introduced into the soil by the way of spiked sewage sludge, simulating agricultural practice and diffuse contamination. The influence of time and initial OTC concentration on the species preservation was evaluated. TBT concentration was shown to have a positive effect on TBT preservation. Corresponding half-lives were calculated. They were 6 ± 1 days and over 39 days for TPhT and TBT, respectively. Degradation compounds, mono- and dibutyltin, and mono- and diphenyltin, were produced by both direct and successive dealkyl and dearylation processes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Influence of organotin compounds on phosphatidylserine membranesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2004José A. Teruel Abstract Organotin compounds are widely distributed toxicants. They are membrane-active molecules with broad biological toxicity. We have studied the interaction of tributyltin and triphenyltin with phosphatidylserine model membranes using differential scanning calorimetry, infrared spectroscopy and X-ray diffraction techniques. Organotin compounds produced a broadening of the gel to the liquid-crystalline phase transition of the phospholipid and a shifting of the phase transition temperature to lower values. Infrared spectroscopy experiments showed that tributyltin exerted a fluidizing effect on the apolar part of the bilayer, and that both tributyl- and triphenyltin interact with the interfacial region of the bilayer, making the carbonyl groups less accessible to water. As seen by X-ray diffraction experiments, organotin compounds were unable to change the bilayer macroscopic organization of the phospholipid, but they were able to reduce the long-range order of the multibilayer system and to disorder the packing of the phospholipid molecules. The observed interaction between organotin compounds and phosphatidylserine membranes promotes physical perturbations that could affect membrane function and may mediate some of their toxic effects. Copyright © 2004 John Wiley & Sons, Ltd. [source] Review: Organotin compounds and their therapeutic potential: a report from the Organometallic Chemistry Department of the Free University of Brussels,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2002Marcel Gielen Abstract An overview of the development of antitumour organotin derivatives is presented and discussed for selected classes of compounds, such as tetraorganodicarboxylatodistannoxanes and related diorganotin dicarboxylates, and for triorganotin carboxylates. Among the carboxylate groups used are steroidcarboxylates and other biologically relevant carboxylates. High to very high in vitro activities have been found, sometimes equalling that of doxorubicin. Solubility in water is an important issue, dominating the in vivo testing of compounds. Polar substituents, like fluorine or polyoxaalkyl moieties, improve the water solubility. Although organotin derivatives constitute a separate class of compounds, the comparison with cisplatin is inevitable. Among the observed toxicities, neurotoxicity, known from platinum cytostatics, and gastrointestinal toxicity, typical for many oncology drugs, have been detected, but to a lower extent. Further research to develop novel useful organotin antitumour compounds needs to be carried out. Copyright © 2002 John Wiley & Sons, Ltd. [source] Synthesis of poly(phenylsilsesquioxane) having organostannyl groupsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2001Yasutaka Matsubara Abstract Poly(phenylsilsesquioxane) (PSQ) having tributylstannyl groups (TBPSQ) was prepared from phenyltrimethoxysilane and bis(tributyltin) oxide [(Bu3Sn)2O] under basic conditions. The procedure, using a catalytic amount of basic reagent such as triethylamine, sodium hydroxide, or aqueous ammonia, afforded yields of TBPSQ based on Si in the range of 12,45% at a number-average molecular weight precipitated from ethanol of about 3500. In the other procedure, starting from PSQ with (Bu3Sn)2O, the incorporation of tributylstannyl groups into PSQ proceeded effectively in the presence of an acid catalyst such as methanesulfonic acid or sulfuric acid, giving TBPSQ in moderate yields of greater than 52%. Dibutyltin oxide, a bifunctional organotin compound, was also used, affording dibutylstannylated poly(phenylsilsesquioxane) (DBPSQ) without crosslinking. The highest ratio of Si and Sn contained in TBPSQ or DBPSQ, prepared under acidic conditions, was Si/Sn = 7/1. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2125,2133, 2001 [source] Supported (nBuCp)2ZrCl2 Catalysts: Effects of Selected Lewis Acid Organotin Silica Surface Modifiers on Ethylene PolymerizationMACROMOLECULAR REACTION ENGINEERING, Issue 4 2008Muhammad N. Akhtar Abstract This study investigated the effects of several organotin silica surface modifiers on the ethylene polymerization performance of (nBuCp)2ZrCl2 -based supported catalysts in which MAO and metallocene were sequentially loaded. Each organotin compound acted as a spacer, increasing the catalyst activity. However, the catalyst activity and of the resulting polyethylenes varied as follows: Activity and fractional Sn+ charge: nBuSn(OH)2Cl,>,MeSnCl3,>,nBuSnCl3,>,Reference catalyst; and, : Reference catalyst,>,nBuSnCl3,>,MeSnCl3,>,nBuSn(OH)2Cl. The above catalyst activity rating was explained considering the influence of the Lewis acidity, that is, the fractional Sn+ charge of the organotin modifiers on the generation, concentration, and electron density at the active [(nBuCp)2ZrMe]+ cation. All the catalysts showed fairly stable kinetic profiles and produced narrow molecular weight distribution resins; 2.8,,,PDI,,,3. [source] Toxicity reduction of metal pyrithiones by near ultraviolet irradiationENVIRONMENTAL TOXICOLOGY, Issue 4 2006Hideo Okamura Abstract Zinc pyrithione (ZnPT) or copper pyrithione (CuPT) have been effectively used as ship-antifouling agents, as an alternative to organotin compounds. Because of their instability in light and a lack of suitable analytical procedures, there is little data on their residue levels in environmental matrices. It is possible to investigate the fate of such compounds by toxicity alteration with certain treatments. The purpose of this study was to evaluate the degradation of pyrithiones through toxicity reduction by near ultraviolet (UV-A) irradiation. Metal pyrithiones dissolved in acetonitrile were irradiated with a UV-A lamp for 0, 0.5, 1, and 2 h, and were subjected to UV spectral measurement and toxicity evaluation using both sea urchin and freshwater rotifer bioassays. For the bioassays, photolyzed samples were dissolved in dimethyl sulfoxide after evaporation of the acetonitrile. The changes in UV spectra of photolyzed ZnPT or CuPT showed a time-dependent degradation, and the UV spectra at 2 h irradiation suggested substantial decomposition. Toxicities of ZnPT and CuPT were 12 and 5 ,g/L as 24 h LC50 to the survival of rotifers and 10,6 ng/L and 2.3 ng/L as 27 h EC50 to normal pluteus formation, respectively. By evaporation of the acetonitrile, the EC50 of ZnPT was 2.2 ng/L, which was the same as that of CuPT. The EC50s of ZnPT or CuPT for both species increased with longer irradiation times. Photolyzed ZnPT or CuPT demonstrated substantial degradation in the UV spectra, but possessed marked toxicity, which is probably due to toxic degradation products. One reason why photolyzed CuPT was toxic to rotifers was explained by the high toxicity of copper ions formed by UV-A irradiation. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 305,309, 2006. [source] Toxicity of tributyltin and triphenyltin to early life-stages of Paracentrotus lividus (Echinodermata: Echinoidea)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2002Alessandra Arizzi Novelli Abstract Sperm cell and embryo toxicity tests using the Mediterranean sea urchin Paracentrotus lividus were performed to assess the toxicity of tributyltin chloride, bis(tributyltin)oxide, triphenyltin acetate, and triphenyltin hydroxide. Toxicity values (mean effective concentration [EC50]) ranged from 2.97 to 18.5 ,g/L for sperm cells and from 1.11 to 2.62 ,g/L for embryos. For sperm cells, the toxicity of the two tributyl compounds was significantly greater than that of two triphenyl compounds; for embryos, the triphenyl compounds appeared to be more toxic. Study of embryotoxic effects highlighted closely concentration-dependent damages, the most sensitive stages corresponding to the crucial phases of differentiation (gastrula and prisma). Both EC50 and no-observed-effect concentration values for the four organotin compounds are similar to those reported in the literature for early life stages of other marine organisms. [source] Three-step synthesis of arylpolyboronic acids from phenols via organotin compoundsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 8 2007Pablo M. Fidelibus Abstract In this paper we describe a three-step synthesis of aryldi- and triboronic acids starting from phenols. Several substituted phenols (I) were converted into the corresponding aryldiethylphosphates (II) in good to excellent yields. The latter, on reaction with sodium trimethylstannide in liquid ammonia, under irradiation, afforded the aryl- and heteroarylpoly(trimethylstannyl) derivatives in 65,90% yield. The third step is the reaction of the organotin compounds with borane in THF, which leads to the corresponding arylpolyboronic acids in around 80% yield. In order to confirm their structure, some of the diboronic acids were converted into the corresponding pinacol esters. The results obtained in a study on the synthesis of various terphenyls through double and triple Suzuki couplings catalyzed by palladium acetate between the obtained arylpolyboronic acids and various aryl halides are also reported. These reactions proceeded with an average 65% yield, and also enabled us to confirm the structures of some of the diboronic acids. The structure of the new compounds was determined by 1H, 13C and 119Sn NMR spectroscopy, mass spectrometry and IR spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd. [source] Mixed aryl,alkyl organotin compounds, ArnMeSnCl3,n (Ar = RC6H4, R = H, ethyl, i-propyl, t-butyl; n -hexyl, n -octyl) and the effect of R upon antibiotic activity,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2005Ramesh N. Kapoor Abstract The synthesis of a new series of arylmethyltin chlorides is reported, ArnMeSnCl3,n (Ar = RC6H4, R = H, ethyl, i-propyl, t-butyl; hexyl, octyl). The synthesis involves initial formation of triarylmethyltin compounds, Ar3MeSn, via Grignard techniques followed by HCl,Et2O aryl group cleavage, preferably in a stepwise manner. Preliminary biological activity against Staphylococcus aureus illustrates the importance of the para-alkyl substituents and reinforces that an optimal hydrophobic character is needed for maximum efficacy. Copyright © 2005 John Wiley & Sons, Ltd. [source] Influence of organotin compounds on phosphatidylserine membranesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2004José A. Teruel Abstract Organotin compounds are widely distributed toxicants. They are membrane-active molecules with broad biological toxicity. We have studied the interaction of tributyltin and triphenyltin with phosphatidylserine model membranes using differential scanning calorimetry, infrared spectroscopy and X-ray diffraction techniques. Organotin compounds produced a broadening of the gel to the liquid-crystalline phase transition of the phospholipid and a shifting of the phase transition temperature to lower values. Infrared spectroscopy experiments showed that tributyltin exerted a fluidizing effect on the apolar part of the bilayer, and that both tributyl- and triphenyltin interact with the interfacial region of the bilayer, making the carbonyl groups less accessible to water. As seen by X-ray diffraction experiments, organotin compounds were unable to change the bilayer macroscopic organization of the phospholipid, but they were able to reduce the long-range order of the multibilayer system and to disorder the packing of the phospholipid molecules. The observed interaction between organotin compounds and phosphatidylserine membranes promotes physical perturbations that could affect membrane function and may mediate some of their toxic effects. Copyright © 2004 John Wiley & Sons, Ltd. [source] A multicriteria ranking of organotin(IV) compounds with fungicidal propertiesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 10 2003Godwin A. Ayoko Abstract The application of multicriteria decision-making methods to the results of in vitro antifungal properties of organotin compounds of the type PhxSnXz (x = 2 or 3; X = O2CC6H4OH, O2CC6H4OCOCH3, Cl or O2CCH3; z = 1 or 2) and of free 2-hydroxybenzoic and 2-acetoxybenzoic acids against Aspergillus niger, Aspergillus flavus, Candida albicans, Penicillium citrinum, Trichophyton rubrum and Trichophyton violaceum have been described. Ranking information necessary to select one toxicant in preference to others and to assess the properties influencing the preference has been obtained. Patterns in the multivariate analyses suggest that cationic and anionic moieties of the toxicant play some roles in their fungicidal activities. The triphenyltin compounds were generally more active than their diphenyltin analogues, but the acetoxybenzoates were more active than the corresponding hydroxybenzoates, acetates or chlorides. Thus, triphenyltin acetoxybenzoate is up to 7.5 times as active as the corresponding acetate, which is commercially marketed as a fungicide. The results of the analyses have been discussed in the light of the mechanism of antifungal activity of organotin compounds and the potential of multivariate data analysis techniques to facilitate the screening and ranking of antifungal agents. Copyright © 2003 John Wiley & Sons, Ltd. [source] Life-cycle toxicity of dibutyltin to the sheepshead minnow (Cyprinodon variegatus) and implications of the ubiquitous tributyltin impurity in test materialAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2003Thomas F. Lytle Abstract Dibutyltin (DBT) is used in the plastics polymerization process as a catalyst in polyvinyl chloride (PVC) products and is the primary degradation product of tributyltin (TBT), an antifoulant in marine paint. DBT and other organotin compounds make their way into the environment through antifoulants, PVC processing plants, and PVC products maintained in water and water-handling systems. A flow-through saltwater life-cycle toxicity test was conducted to determine the chronic effect of DBT to the sheepshead minnow (Cyprinodon variegatus Lacepede), an estuarine species. Embryos were monitored through hatch, maturation, growth, and reproduction in DBT concentrations of 158, 286, 453, 887, and 1510 µg l,1. Progeny were monitored for survival as embryos and fry/juveniles, and growth for 30 days post-isolation. Mean length of parental generation fish was significantly reduced on day 30 at DBT concentrations ,887 µg l,1, setting the lowest observable effect concentration (LOEC) at 887 µg l,1 and the no observable effect concentration (NOEC) at 453 µg l,1. Fecundity, as egg viability, was significantly reduced at the LOEC. Survival of parental and progeny generation embryos and mean length, wet weight and dry weight of progeny generation juveniles were not significantly affected at concentrations ,LOEC. TBT, a toxic impurity in DBT reversibly produced in DBT by the process of comproportionation, was also monitored throughout this study. Comparing measured levels of TBT in this study with levels exerting toxic effects in an earlier TBT life-cycle study with C. variegatus suggests biological responses in this study were likely due to the TBT impurity and not to DBT alone. Results indicate that TBT impurity as low as 0.1% may have a significant influence on the perceived toxicity of DBT and that spontaneous production of TBT in DBT may be the major source of biological toxicity of DBT. Copyright © 2003 John Wiley & Sons, Ltd. [source] Organotin antifouling paints and their alternativesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 2 2003Iwao Omae Abstract Tributyltin and triphenyltin compounds have excellent biocidal properties and almost all vessels in the world have used these paints since early in the 1960s. Contrary to expectation, as shown by experimental data at the beginning of organotin chemistry, triorganotins are exceptionally stable in the sediment or in dark places in the deep sea. Since triorganotins do not decompose rapidly in seawater, many incidences of deformities in some shellfish have been linked to their presence, even when present at extremely low concentrations. Alternative tin-free antifoulants containing other biocides, such as copper compounds and organic compounds, have been developed and used since the late 1980s. Some nations have already banned the use of organotin antifouling compounds for small vessels, and in 2001 the International Maritime Organization decided to ban completely the use of the organotin compounds from the year 2003. Therefore, it is necessary to find economically and environmentally better biocidal substances as soon as possible. Moreover, the development of antifoulants containing environmentally safe natural products, fouling release coatings, electroconductive coatings, etc. have long been anticipated from the new point of conservation of the world marine environment. Copyright © 2003 John Wiley & Sons, Ltd. [source] Review: Biodegradation of tributyltins (organotins) by marine bacteriaAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2003S. K. Dubey Abstract Many marine bacterial strains have an inherent capability to degrade toxic organotin compounds, especially tributyltins (TBTs), that enter into the environment in the form of insecticides, fungicides and antifouling paints as a result of anthropogenic and industrial activities. Significant degradation of these compounds in the ambient environment may take several years, and it is necessary to consider methods or strategies that can accelerate the degradation process. There have been few demonstrations of biological degradation of these organotin biocides exclusively in laboratory-scale experiments. Compared with the few bench-scale degradation processes, there are no reports of field-scale processes for TBT bioremediation, in spite of its serious environmental threat to non-target organisms in the aquatic environment. Implementation of field-scale biodegradation of TBT requires inputs from biology, hydrology, geology, chemistry and civil engineering. A framework is emerging that can be adapted to develop new processes for bioremediation of toxic environmental wastes. In the case of TBT bioremediation, this framework incorporates screening and identification of natural bacterial strains, determination of optimal conditions for growth of isolates and TBT degradation, establishment of new metabolic pathways involved in TBT degradation, identification, localization and cloning of genes involved in degradation and in TBT resistance, development of suitable microbial strains using genetic manipulation techniques for practical applications and optimization of practical engineering processes for bioremediation of organotin-contaminated sites. The present review mainly addresses the aspect of TBT biodegradation with special reference to environmental sources of TBT, chemical structure and biological activity, resistant and degrading bacterial strains, possible mechanisms of resistance and degradation and the genetic and biochemical basis of TBT degradation and resistance. It also evaluates the feasibility and potential of natural and genetically modified TBT-degrading bacterial strains in field-scale experiments to bioremediate TBT-contaminated marine sites, and makes recommendations for more intensive and focused research in the area of TBT bioremediation mediated by marine bacterial strains. Copyright © 2002 John Wiley & Sons, Ltd. [source] Organotin levels in the Ria Formosa lagoon, PortugalAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 7 2002M. R. Coelho Abstract Organotin concentrations were measured in water, sediments and clams (Ruditapes decussatus) from 11 sites in the Ria Formosa lagoon, Portugal, in 1992,93. Results showed a marked spatial pattern of tributyltin (TBT) and dibutyltin concentrations. The highest organotin concentrations were observed at Olhão (site 5), where the most important fishing harbour of the Southern coast of Portugal is located. Results indicated that fishing vessels, moored in the harbour at Olhão (site 5), were the major source of organotin contamination to the lagoon. No significant seasonal trend was observed, suggesting a continuous input of organotin compounds throughout the year. In several areas of the lagoon the TBT burdens in R. decussatus could have deleterious developmental effects. Copyright © 2002 John Wiley & Sons, Ltd. [source] Emission to air of volatile organotins from tributyltin-contaminated harbour sedimentsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2002Alfred J. Vella Abstract An analytical method for determining the presence in air of volatile forms (e.g. chlorides) of tributyltin (TBT) and that of methylbutyltins MenBu(4,n)Sn (n,=,1,3) was developed and used to establish whether dredged harbour sediments contaminated with TBT served as sources of air pollution with respect to organotin compounds. The method was based on active sampling of the air being analysed and sorption of analytes onto Poropak-N. Sorbed methylbutyltins were extracted with dichloromethane and analysed by gas chromatography using flame photometric detection. Other butyltins were converted into butyltin hydrides prior to analysis by gas chromatography. It was shown that TBT-contaminated sediments from Marsamxett Harbour, Malta, placed in 0.5 l chambers through which air was displaced by continuous pumping for 11 days released mainly methylbutyltins, with concentrations (as tin) reaching maximum 48,h mean values of 8.7 (Me3BuSn), 22.1 (Me2Bu2Sn) and 93.0,ng m,3(MeBu3Sn) being measured. Other volatile forms of TBT, dibutyltin and monobutyltin were detected in the headspace air, but very infrequently and at much lower tin concentrations (<2,ng m,3). It was also shown that methylbutyltins dissolved in sea-water ([Sn],=,0.2 to 400,ng l,1) were very difficult to exsolve from this medium, even on prolonged evaporation of the solutions using mechanical agitation and active ventilation. The results suggest that emission of methylbutyltins from contaminated sediments probably occurs only from the surface of the material. The environmental implications of these findings in the management of TBT-polluted harbour sediments are discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of different organotin compounds on DNA of gilthead sea bream (Sparus aurata) erythrocytes assessed by the comet assay,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2002Rosita Gabbianelli Abstract The ,comet' assay appears to be a promising tool for estimating DNA damage at the single cell level. We used this test to evaluate the effect of organotin compounds on sea bream nucleated erythrocytes. The tributyltin chloride (TBTC), dibutyltin chloride (DBTC) and monobutyltin chloride (MBTC) employed in this study show different genotoxicities. TBTC and DBTC have pronounced effects on tail length, tail intensity and tail moment, though TBTC is more efficient in producing DNA damage. MBTC leads to a fast genotoxic effect that does not change with the incubation time. The data obtained are important for the analysis of the environmental risks produced by organotin compounds used as antifouling agents in marine paints and as biocides in agriculture. Copyright © 2002 John Wiley & Sons, Ltd. [source] | |||||||||||||