Sökning: "trace metal"

Visar resultat 1 - 5 av 81 avhandlingar innehållade orden trace metal.

  1. 1. Membrane-based sample pre-treatment strategies in ultra-trace determination of metal ions in complex matrices

    Detta är en avhandling från Analytical Chemistry, Lund University

    Författare :Nii-Kotey Djane; [1997]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PSA; AAS; coupled-counter transport; complex matrix; preconcentration; trace metal; sample pre-treatment; Membranes; automation; ICP-MS; Analytical chemistry; Analytisk kemi;

    Sammanfattning : In the present thesis, analytical sample pre-treatment methods for the determination of trace metal ions in complex matrices were developed and tested. These methods were based on membrane fractionation, clean-up and enrichment of analytes and applied to the determination of aluminium, cadmium, cobalt, chromium, copper, nickel and lead in biological and environmental samples. LÄS MER

  2. 2. Iron or Copper? - Method Development and Mechanistic Studies on Cross-Coupling Reactions

    Detta är en avhandling från Analytical Chemistry, Lund University

    Författare :Per-Fredrik Larsson; Göteborgs universitet.; Gothenburg University.; [2012]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Iron; Copper; Transition metal; Cross-coupling; Reaction mechanism; Kinetic investigation; Hammett study; Sustainable catalysis; Trace-metal; Mass-transfer; Ligand development; Ligand scope;

    Sammanfattning : The area of catalysis has had an immeasurable impact on modern society. This has been acknowledged through several Nobel prizes during the 20th century ranging from Haber (1918) for the synthesis of ammonia to Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki (2010) for palladium-catalyzed cross-coupling reactions. LÄS MER

  3. 3. Trace metal speciation in the Baltic sea

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Johan Gelting; Luleå tekniska universitet.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : Physicochemical speciation of metals in natural waters is very important for understanding their distribution, mobility, bioavailability and toxicity. To be able to understand the behaviour of an aqueous element and the transformation between chemical and physical species, there is a need for reliable methods that enable measurements of specific fractions of metals. LÄS MER

  4. 4. The trace of metals : Use, emissions and sediment load of urban heavy metals

    Detta är en avhandling från Linköping : Linköpings universitet

    Författare :Arne Jonsson; Linköpings universitet.; Linköpings universitet.; [2000]
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

    Sammanfattning : Urban areas have been considered potential ecological hot spots for metal pollution. This is the result of three trends. First, the 20th century saw a rapid increase in the use of many materials, including metals, in the industrialized world. Second, urbanization has made towns and cities areas nodes of material flows. LÄS MER

  5. 5. Liquid Membrane Techniques for Trace Metal Analysis and Speciation in Environmental and Biological Matrices

    Detta är en avhandling från Department of Analytical Chemistry, Lund University

    Författare :Kuria Ndung'u; Lund University.; Lunds universitet.; [1999]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Pb and Organotin species; MMLLE; SLM; GC MS; PSA; GFAS; FAAS; ICP-MS; Speciation; DEHPA; Aliquat-336; trace metals; Cr III ; Cr VI ; Analytisk kemi;

    Sammanfattning : In this thesis, liquid-membrane-based methods for the analysis of trace metal species in samples of environmental and biological origin were developed. By incorporating extracting reagents in the membrane liquid, trace metal ions were selectively separated from humic-rich natural waters and urine samples, prior to their determination using various instrumental techniques. LÄS MER