Determination of arsenic and selenium compounds in water samples organotin compounds in fish samples by LC-ICP-MS

Mono- and di-alkyltins are used extensively as heat stabilizers for processing of poly vinyl chloride (PVC). Tin mercaptide stabilizers are some of the most effective PVC stabilizers available. The main applications for tin stabilizers are building/construction products, such as pipes, fittings, siding and profiles (windows etc.), packaging and flexible PVC plastics. Most PVC products have been and are subjected to landfilling, when their use is terminated. The structure of the polymer itself and the substances used as additives have been a concern for environmental authorities in many countries since long, which also includes their presence in landfills. In the case of the organotin stabilizers their leaching out from (PVC) plastics into the leachate phase of landfills with the risk for further transport to ground and surface waters is in focus. The main objectives of this thesis take their start in this background and, thus, included the elucidation of whether organotin compounds (OTs) in stabilized PVC products contribute to the pool of OTs observed in landfill leachates and if these compounds are degradable by the microorganisms developing under anaerobic landfill conditions. To reach these aims and the research questions raised the forwarded PVC materials were added to muniscipal solid waste (MSW) processed in containers used to simulate the ageing of landfills under forced conditions. These include traditional landfill simulation reactors (LSRs) at a scale of ca 100 L and also at a smaller scale ca 5 L constructed for the purpose of this study, i.e. the modular environmental test system (METS). The latter were used to investigate temperature effects on the possible release of OTs from different types of PVC materials. The capacity by microorganisms in landfill environments were used to investigate their capacity to degrade or transform organotin stabilizer compounds focused on in this thesis. Differences in this capacity in relation to the ageing of landfills and exposure to the alkyltin stabilizers were studied with microorganisms sampled from LSRs spiked with PVC over time and from landfill site. Access to sensitive and reliable equipment and analytical protocols for the analysis of OTs and their transformation intermediates and end products are prerequisites for this kind of studies. This necessitated an adoption and adaptation of analytical methods for the low concentrations occurring in the environment. Two methods were established and well served the requirements. Indeed OTs migrated out from especially flexible PVC materials, while rigid PVC was less prone for OT release as judged from the METS simulations. The METS studies showed that the OT release increase substantially at higher temperatures and especially so when the temperature was higher than the glass transition of the PVC.materials. The organotin stabilizers were transformed, partly or completely degraded, by anaerobic microorganisms derived from landfill environments. Upon prolonged exposure to OTs leaching from PVC in LSR simulations the microorganisms displayed a higher efficiency in degradation of the leached OTs. The microorganisms would methylate inorganic tin and metyltin present in the MSW material as well as perform dealkylation depending on the tin concentrations prevailing. During these studies it was discovered that the organotin stabilzers were inhibiting the methanogens and fermentative bacteria, which lead to a retardation of the anaerobic mineralisation of the MSW in the assays. An in depth study revealed that the OTs themselves but also their ligands and degradation products from these together effected the inhibition. However, given the extent of leaching in relation to the water flows in landfills, the concentrations will mainly be too low to pose any risks to the surrounding environment.

Thesis (M.S.)--Florida State University, 2005. / Advisor: Dr. Igor Alabugin, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains xv, 123 pages. Includes bibliographical references.

Thesis (Ph. D.)--Carleton University, 2004. / Includes bibliographical references (p. 152-160). Also available in electronic format on the Internet.

abstract / Biological Sciences / Doctoral / Doctor of Philosophy

Trimethyltin fluoride (Me3SnF) is a useful fluorinating agent in organometallic chemistry. Its solid-state structure has been investigated by X-ray crystallography showing a polymeric fluorine-bridged structure. Disorder, however, has precluded the accurate refinement of all structural parameters. In order to obtain accurate structural information, trimethyltin fluoride was investigated using high-resolution 13C, 19F, and 119Sn solid-state NMR spectroscopy using a four-channel HFXY capability. The 119Sn{1H} solid-state NMR spectrum agrees with pentacoordination about Sn in this compound. The high-resolution 119Sn{19F, 1H}, 13C{1H,19F} and 19F{1H} NMR spectra offer unambiguous determination of 1J(119Sn-19F) and 1J(119Sn-13C) coupling constants. Furthermore, the analysis of the 119Sn{19F, 1H}, 119Sn{1H}, and 19F{1H} MAS spectra as a function of spinning speed allowed for the determination of the 119Sn CSA and J anisotropy, as well as the 119Sn-19F dipolar couplings. These were determined via SIMPSON simulations of the 13C, 19F, and 119Sn NMR spectra. Finally the 119Sn{19F, 1H} revealed fine structure as the result of 119Sn-117Sn two bond J-coupling, seen here for the first time. Sulfur tetrafluoride can act as a Lewis acid. Claims had been presented for the formation of an adduct between SF4 and pyridine, but no conclusive characterization had been performed. In the present study, adducts of SF4 with pyridine, lutidine, 4-picoline and triethylamine were prepared and characterized by low-temperature Raman spectroscopy. Sulfur tetrafluoride also acts as a fluoride-ion donor towards strong Lewis acids, such as AsF5 and SbF5, forming SF3 + salts. Variable-temperature (VT) solid-state 19F NMR spectroscopy showed that SF3 +SbF6 – exists in three phases with phase transitions at ca. –45 and –85°C, while SF3 +AsF6 – exists only as one phase between +20 and –150 °C. The phases of SF3 +AsF6 – were also characterized by VT Raman spectroscopy. / xvi, 170 leaves : ill. (some col.) ; 29 cm

Toxic antifouling agents such as tributyltin (TBT) and triphenyltin (TPT) have been released in aquatic ecosystems through the use of antifouling paint applied to ship hulls, pleasure crafts and fish nets. The purpose of this study was to assess the use of zebra mussels (Dreissena polymorpha ) as a biomonitor for investigating the geographical variations of organotin bioavailability along the St. Lawrence River. Organotins TBT and TPT and their degradation products were first measured in the soft tissues of zebra mussels collected from along the River. High concentrations of TBT were found in mussels from Bassin Louise, a marina in Quebec City (1442 ng/g wet weight). TPT concentrations were elevated at 2 sites near Quebec City (252 and 530 ng/g wet weight). A follow-up study assessed the extent of the distribution of organotins from the contaminated marina to the River system by measuring organotin concentrations in zebra mussels and in sediments collected River near Quebec City. The highest concentration of TBT was found in Bassin Louise (1078 ng/g wet weight) and elevated concentrations were found in two other marinas. The concentrations decreased sharply to background levels just outside the marinas. All butyltins were detected in all sediments analysed. There was a significant correlation between TBT in sediments and mussels. These studies suggest that organotin contamination may remain a problem in localized freshwaters in the St. Lawrence River.

Organotin compounds are one of the most produced and most used organometallic compounds. Some of these substances are endocrine disruptors, persistent organic polutants and their high toxic effects are observed. That’s why their presence in the environment caused by human activity could endanger many organisms. The aim of this thesis is summarize their properties and their occurrence in the environment. Then the quick, easy and relatively cheap method for determination of trialkyltin compounds in heavily poluted aquatic sediments using capillary zone electrophoresis is developed.

Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Chemistry in the Faculty of Applied Sciences at the Cape Peninsula University of Technology 2013 / In this present study, the physicochemical properties, nature and morphology of prepared composite materials involving activated carbon, fly ash, nFe3O4, nSiO2 and nZnO in the 1:1 ratio for two components composite materials and 1:1:1 for three components composite materials were investigated. The nature, morphology and elemental characterizations of these materials were carried out by means of modern analytical methods such as scanning electron and transmission electron microscopy (SEM and TEM), x-ray diffraction (XRD), x-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared spectroscopy (FTIR). Other physicochemical characterizations undertaken were CNH analysis, ash content, pH, point of zero charge and surface area and porosity determination by Brunauer, Emmett and Teller (BET). The precursors and composite materials were then applied to the sorption (remediation) of tributyltin (TBT) and triphenyltin (TPT) from artificial seawater and wastewater and the adsorption efficiencies for the precursors and the composites compared. The adsorption of TBT and TPT onto these materials as a function of adsorbent amount, contact time, pH, stirring speed, initial adsorbate concentration and temperature was investigated. Maximum organotin adsorption was recorded within the pH range of normal saline water (pH 8). Approximately 99.95 %, 95.75 %, 96.78 %, 99.88 %, 96.96 %, 99.98 %, 99.99 %, 99.99 % and 99.99 % TBT were removed from 25 mL of 100 mg/L TBT-contaminated artificial seawater using 0.5 g adsorbents at a contact time of 60 min, pH 8, stirring speed 200 rpm and temperature of 80 oC by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/activated carbon, nSiO2/activated carbon and nZnO/activated carbon composite, respectively and the adsorption of TBT onto these adsorbents was endothermic. Approx. 99.99 %, 96.54 %, 95.50 %, 96.92 %, 97.14 %, 99.99 %, 98.44 %, 98.98 % and 99.66 % TPT were also removed from 25 mL of 100 mg/L TPT-contaminated artificial seawater using 0.5 g adsorbents at a contact time of 60 min, pH 8, stirring speed 200 rpm and a temperature of 20 oC by the activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composite, respectively. The adsorption of TPT onto activated carbon and fly ash/activated carbon composite from TPT – contaminated artificial seawater was endothermic while TPT adsorption onto fly ash, nFe3O4, nSiO2, nZnO, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composites from TPT – contaminated artificial seawater was exothermic. The adsorption of TBT and TPT onto nFe3O4/fly ash/activated carbon and nSiO2/fly ash/activated carbon composites from TBT – and TPT – contaminated water, respectively were endothermic and approx. 99.98 % and 99.99 % of TBT and TPT, respectively were removed from the initial concentration of 100 mg/L OTC by the composites at a temperature of 80 oC, 60 min contact time, pH 8 and a stirring speed of 200 rpm. The adsorption kinetics of all the precursors and composite materials fitted well with the pseudo second-order kinetic model while the adsorption isotherm data could be well described by the Freundlich isotherm model except TBT adsorption onto nZnO/activated carbon and nFe3O4/activated carbon composite from TBT contaminated artificial seawater, TPT adsorption onto activated carbon and fly ash/activated carbon from TPT contaminated artificial seawater, and TPT sorption onto nSiO2/fly ash/activated carbon composite from TPT – contaminated water which could be described by both the Freundlich and Dubinin-Radushkevich (D-R) isotherm models. Optimal conditions for the adsorption of TBT and TPT from artificial seawater were further applied to TBT and TPT removal from TBT – and TPT – contaminated natural seawater obtained from Cape Town harbour and the results obtained show that 99.71 %, 79.23 %, 80.11 %, 82.86 %, 80.42 %, 99.75 %, 99.88 %, 99.83 % and 99.88 % TBT were removed from TBT – contaminated natural seawater by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/activated carbon, nSiO2/activated carbon and nZnO/activated carbon composite, respectively while 99.90 %, 96.44 %, 95.37 %, 96.75 %, 97.03 %, 99.92 %, 98.42 %, 98.92 % and 99.58 % TPT were removed from TPT – contaminated natural seawater by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composite, respectively. Experimental results therefore show that the composite materials present higher organotin adsorption efficiency than the precursors due to the nature and improved properties of the composite materials and can therefore be utilized for the remediation of organotin contamination from industrial and/or shipyards process wastewater to > 99 % reduction before discharge into the environment.

No description available.