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

The goal of this study is to establish an accurate, simple and fast method for analysis of organotin in bio-tissues and for routine analysis of organotin in pollution control. This study also conducted the field survey investigating the accumulation status of butyltin (BT) in organisms and environments for validation of analytical method and applicability in different environmental samples. Stations had been set up from the Sih-Cao fishing port to the upstream of Luermen Stream Estuary. General water quality factors were measured in situ, and water samples, suspended particles, Pacific oysters (Crassostrea gigas), green mussels (Perna viridis), and rockshells (Thais clavigera and Thais rufotincta) were collected in summer (July 2003) and winter (February 2004) seasons and the concentrations of butyltins were measured. Surface sediment samples were also collected from each sampling station and the concentrations of butyltins were measured to present pollution status of butyltins in Luermen Stream Estuary. To determine butyl- and phenyl-tins in fish muscle, a method including base digestion pretreatment, followed by an ethylation-extraction procedure together with gas chromatography-flame photometric detection (GC-FPD) analysis is outlined. Parameters that affect analyte recovery were investigated and optimized. A solution of 3 % (w/v) potassium hydroxide and 1 h digestion time at 60 ¢J were chosen in the base digestion step to ensure complete solubilization of fish muscle and the decomposition of organotins was found to be negligivle. We found that the ratio of fish muscle/reaction solution volume should not exceed 0.2 g (dry weight) per 100 mL in order to avoid the matrix effect caused by the binding of hydrolyzed fish tissue with organotin ions. Ethylation of organotins were conducted at pH 6~7 with a 1 % (w/v) sodium tetraethylborate (NaBEt4) solution for 1 h. This simple and timesaving procedure could be applied to the routine analysis of organotins in other bio-tissues. The BT content of environments and organisms reflected that the tributyltin (TBT) pollution levels were higher in Sih-Cao fishing port than in Luermen Stream. The BT content of organisms reflected more detail TBT pollution status between Sih-Cao fishing port and Luermen Stream. However, the MBT pollution status in Luermen Stream was not reflected in MBT accumulation status of organisms. The ability of TBT accumulation in oysters and mussels was higher than in rockshells. Moreover, oysters had higher TBT accumulation ability than mussels at lower TBT pollution level, but following the increase of TBT pollution level, the ability of TBT accumulation in oysters had shifted to be lower than in mussels. The results also showed that in the higher TBT pollution level, the ratios of MBT and DBT over the total butyltins had changed to higher status and the bioaccumulation factors (BAF) had changed to smaller values in oysters and rockshells. In mussels, this phenomenon was not significant. However, the organisms (oyster, mussel and rockshells) revealed smaller BAF of TBT in Luermen Stream than in the Sih-Cao fishing port entrance. For oysters and mussels, the TBT contents and the composition ratios of TBT in total butyltins were both higher in winter season. All organisms (oysters, mussels and rockshells) had higher ability to accumulate TBT according to the larger BAF observed in summer season. The ability of TBT accumulation in rockshells was lower than in oysters or mussels. Moreover, the BT accumulation status was mainly composed of MBT and DBT (the metabolites of TBT ) in rockshells and TBT in oysters and mussels. That was attributed to higher metabolic rate of TBT in rockshells.

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.

La Directive Cadre sur l'Eau (DCE) (2000/60) a mis en place une liste de 33 substances prioritaires, avec des normes qualité de l'environnement (NQE) pour chaque substance, et leur concentration dans les milieux aquatiques qui ne doivent pas dépasser c es NQE. De plus, elle exige des performances analytiques spécifiques pour ces méthodes: la limite de quantification doit être au moins aussi basse que 30% des NQE et l'incertitude de la méthode au niveau de la NQE doit être inférieure à 50%, pour k = 2. Par conséquent, le défi analytique actuel est de mesurer de faibles concentrations de ces polluants dans les matrices parfois difficiles. Ceci peut être réalisé en améliorant la technique d'extraction utilisée pour obtenir un extrait de l'échantillon plus concentré et plus propre. Dans ce contexte, les trois méthodes d'analyse ont été mises au point pour déterminer les composés musqués, alkylphénoliques et organométalliques dans les matrices environnementales. Ces techniques d'extraction et de pré-concentration innovantes ont ensuite été appliquées pour l’évaluation de la présence de ces composés dans les stations d'épuration locales et dans les cours d'eau récepteurs. Enfin, les niveaux de concentrations de fond au niveau national ont été mises à jour pour les composés organométalliques. / The ambitious Water Framework Directive (WFD) (2000/60) set up a list of 33 priority substances, with Environmental Quality Standards (EQS) for each substance, and their concentration in aquatic environments should not go beyond the EQS. Additionally, it requires specific analytical method performances: the limit of quantification must be at least as low as 30 % of the EQS and the uncertainty of the method at the EQS level must be inferior to 50 %, for k=2. Therefore, the current analytical challenge is to measure low concentrations of these pollutants in sometimes difficult matrices. This can be achieved by improving the extraction technique used to obtain a more concentrated and cleaner sample extract. In this context, 3 analytical methods were developed to determine musk, alkylphenols and organometallic compounds in environmental matrices. Recent extraction and pre-concentration techniques were applied and later the occurrence of these compounds in the local WWTPs and in the receiving water bodies where they are discharged was evaluated. Additionally, updated French background concentrations were established for organometallic compounds.

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

New methodologies have been developed for the determination of organotin and organolead compounds in environmental samples. Several high performance liquid chromatographic separations of organotin compounds have been tested and the best system (cation-exchange chromatography with methanol and a citrate buffer) employed for the determination of tributyltin (TBT), triphenyltin (TPhT), dibutyltin (DBT) and monobutyltin (MBT) in environmental samples. The coupling between high performance liquid chromatography (HPLQ and the inductively coupled plasma-mass spectrometer (ICP-MS) for this application has been modified to yield limits of detection of 0.44,0.26,1.4 and 0.23 ng. g-' as Sri for TBT, TPhT, DBT and MBT respectively. Different extraction procedures have been tested for the determination of organotin species in samples of environmental interest, such as sediments and biological materials. The values obtained for TBT, TPhT and DBT in the analysis of a mussel candidate reference material, CRM 477, have been incorporated in the certification campaign of this material. A liquid chromatographic separation for trimethyllead (TML) and triethyllead (TEL) has also been developed. Artificial rain water has been analysed for TML. The system proved to be valid for the determination of TML in this sample, even in the presence of high amounts of inorganic lead. Finally, isotope dilution analysis (IDA) was incorporated in the method. Tributyltin iodide (TBTI) and trimethyllead chloride (TMLCI), isotopically enriched in "Sn and "Pb, respectively, were synthesised. The mussel tissue CRM 477 was analysed with IDA-HPLC-ICPMS for TBT. As for the analysis without isotope dilution, the result obtained was incorporated in the certification campaign. The analysis with this methodology gave a better precision in the overall determination than external calibration analysis. Artificial rain water, at two different concentration levels, was analysed for TML with IDA-HPLC-ICP-MS. Better precision and accuracy was obtained for the analysis of this material with this method than when external calibration procedures were employed. IDA-HPLC-ICP-MS has proved to be a valid technique for the analysis of environmental samples. The technique simplifies the procedure, compensates for different sources of variability and, thus, the overall precision obtained in the analysis is improved compared to other calibration techniques.

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.