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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 348 (1994), S. 792-805 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Selenium, like sulphur, exists in the environment in several oxidation states and as a variety of inorganic and organic compounds. Dissolved inorganic selenium can be found in natural waters as selenide Se (−II), as colloidal elemental selenium Se (0), as selenite anions HSeO 3 − and SeO 3 2− i.e. Se (+IV) and as the selenate anion (SeO 4 2− ) i.e. Se (+VI). Organic forms of selenium that may be found in organisms, air or in the aqueous environment, are volatile (methylselenides) or non volatile (trimethylselenonium ion, selenoamino acids and their derivatives). Knowledge of the different chemical forms and their environmental and biomedical distribution is important because of the dependence of bioavailability and toxicity on speciation. This paper reviews the different analytical methods used for the speciation of selenium compounds, with special attention to inorganic selenium and organoselenium species.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0268-2605
    Keywords: Speciation ; buyltin compounds ; marine biota ; hydride generation ; atomic absorption ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The determination of tributyltin (TBT) in sea food (mussel, oyster, fish) by a hydride generation-cold trapping-quartz furnace atomic absorption spectrometry procedure has been studied with emphasis on quality control. Large amounts of spiked materials have been prepared and stored either frozen, or frozen after freeze-drying. Extraction of TBT by 0.1 M hydrochloric acid in methanolic solution is efficient (88-96%) for wet samples or freeze-dried samples. It is also efficient with freshly spiked materials. Consumption of sodium borohydride by the matrix makes it necessary to use quite large amounts of reagent to obtain optimal sensitivity. Analysis of a fish-tissue Certified Reference Material seems to indicate a partial debutylation of TBT during transport and/or storage of this material.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 8 (1994), S. 639-644 
    ISSN: 0268-2605
    Keywords: Interlaboratory study ; harbour sediment ; analytical quality control ; reference material ; tributyltin ; dibutyltin ; monobutyltin ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Following two interlaboratory studies on tributyltin species (TBT) in water and TBT-spiked sediment, the EC Community Bureau of Reference (BCR) (Measurements and Testing Programme) organized in 1992 an interlaboratory study on TBT in a harbour sediment (RM 424) to investigate sources of error possibly occurring in the analysis of a complicated matrix and to attempt to certify this material. The sediment was collected in the Sado Estuary (P), then carefully prepared, and its homogeneity and stability were verified. The low TBT content encountered in this material, and the high level of interferences, created difficulties with the techniques using hydride generation, whereas better agreement was obtained for other derivatization techniques with GC/FPD and GC/MS. This paper presents the results of the interlaboratory study. The reference value for TBT in this material is 20±5 ng g-1 (as TBT cation) and the indicative values for dibutyltin (DBT) and monobutyltin (MBT) are 53±19 ng g-1 (as DBT cation) and 257±54 ng g-1 (as MBT cation), respectively. Owing to the difficulties encountered, the reference material was not certified and is considered as a research material to be used for the evaluation of the performance of analytical techniques for the determination of low TBT levels in a difficult matrix.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0268-2605
    Keywords: Certified Reference Material ; coastal sediment ; analytical quality control ; tributyltin ; dibutyltin ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Determinations of tributyltin (TBT) species, along with the degradation products mono- and dibutyltin (MBT and DBT), are routinely carried out by a number of laboratories to ascertain the level of organotin contamination of the marine enviroment, particularly in water, sediment and biota. In order to improve and control the quality of such analyses the EC Community Bureau of Reference, BCR (Measurements and Testing Programme), has organized two interlaboratory studies on TBT in water and TBT in a spiked sediment which were followed by a certification campaign for butyltins in a coastal sediment (CRM 462). This material was collected in the Arcachon Bay (France), then carefully prepared (controlled oven drying) and its homogeneity and long-term stability were verified. This paper presents the certification work performed. The certified values for TBT and DBT are 70±14 ng g-1 (as TBT cation) and 128±16 ng g-1 (as DBT cation), respectively.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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