Sökning: "isotope dilution analysis"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden isotope dilution analysis.

  1. 1. Instrumental and methodological developments for isotope dilution analysis of gaseous mercury species

    Författare :Tom Larsson; Erik Björn; Holger Hintelmann; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mercury; gas; species; speciation analysis; isotope dilution analysis; permeation tubes; Analytical chemistry; Analytisk kemi;

    Sammanfattning : This thesis deals with instrumental and methodological developments for speciation analysis of gaseous mercury (Hg(g)), based on isotope dilution analysis (IDA). The studied species include Hg0, (CH3)2Hg, CH3HgX and HgX2 (where X symbolises a negatively charged counter ion in the form of a halide or hydroxyl ion). LÄS MER

  3. 2. Speciation analysis of butyl- and phenyltin compounds in environmental samples by GC separation and atomic spectrometric detection

    Författare :Dong Nguyen Van; Wolfgang Frech; Anders Cedergren; Erwin Rosenberg; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organotin speciation analysis; species-specific isotope dilution; inductively coupled plasma mass spectrometry; single isotope spike; multi-isotope spike; redistribution; species transformation; preparative liquid chromatography; gas chromatography; line source atomic absorption spectrometry; continuum source atomic absorption spectrometry; Analytical chemistry; Analytisk kemi;

    Sammanfattning : The main goal of the work presented in this thesis is to improve the reliability of existing methods for speciation analysis of organotin compounds Species-specific isotope dilution (SSID) calibration in combination with gas chromatography – inductively coupled plasma mass spectrometry was used to investigate the transformation of phenyltin species during sample preparation. Isotope-enriched phenyltin species were synthesized from corresponding isotope-enriched tin metals. LÄS MER

  4. 3. Isotope Ratio and Trace Element Measurements Using Inductively Coupled Plasma – Mass Spectrometry : Method Development and Applications in Environmental Forensics

    Författare :Simon Pontér; Anders Widerlund; Hjalmar Laudon; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Isotope ratio measurements; screening analysis; ICP-MS; MC-ICP-MC; multi-tracer studies; fractionation; Environmental Forensics; Tracing; Tillämpad geokemi; Applied Geochemistry;

    Sammanfattning : Environmental Forensics is a scientific methodology developed for identifying sources, the timing of release, and transport pathways for potentially hazardous environmental contaminants. It combines a variety of analytical methods with principles derived from disciplines such as chemistry, geology, geochemistry, hydrogeology, and statistics, with the purpose to provide objective scientific and legal conclusions on the source and/or time of a contaminant release. LÄS MER

  5. 4. Quantitation of gluconeogenesis in humans

    Författare :Karin Ekberg; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Gluconeogenesis; mass isotopomer distribution analysis; deuteratedwater; hexamethylenetetramine; splanchnic and renal glucose production;

    Sammanfattning : Several methods have been introduced for estimating gluconeogenesis, but none provides a direct measurement without assumptions that condition the accuracy of the estimate. The aim of this work has been to develop a new method for quantitative studies of gluconeogenesis, applicable in humans. LÄS MER

  7. 5. Determination of actinides using ICP-SFMS

    Författare :Ulrika Nygren; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

    Sammanfattning : Interest in the determination of the actinides using ICP-MS has steadily increased with the development of systems capable of more sensitive and precise measurements. However, the analysis of less abundant actinides such as Pu and Am is not straightforward due to the need for chemical separation of these elements prior to determination. LÄS MER