Avancerad sökning

Hittade 4 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Development of GC-HRMS procedures for determination of naturally occuring polar compounds in various environmental applications

    Författare :Bodil Widell; Dag Broman; Caroline Leck; Joan Grimalt; Stockholms universitet; []
    Nyckelord :GC-HRMS; steroid hormones; amino acids; perch; size-resolved aerosol; Arctic; NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : The overall objectives of this dissertation were to gain further understanding of the two following environmentally significant issues: (i) Determination of natural steroid hormones in blood plasma from perch (Perca fluviatilis) during a reproductive cycle and to evaluate the possibility of using the steroid composition as a biomarker for early signs of endocrine disruptive effects. (ii) Determination of dissolved free amino acids in size resolved airborne particles collected over the Arctic pack ice area (>80°N) in summer and to study their overall relationship with the ocean surface microlayer as a potential source. LÄS MER

  3. 2. PLE with integrated clean up followed by alternative detection steps for cost-effective analysis of dixons and dioxin-like compounds

    Författare :Erik Spinnel; Peter Haglund; Patrik Andersson; Tuulia Hyötyläinen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pressurized liquid extraction PLE ; PLE-C; modular PLE; ELISA; dioxin; dioxin-like compounds; GCxGC; analytical methods; Environmental chemistry; Miljökemi;

    Sammanfattning : Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are two structurally related groups of chemicals, generally referred to as `dioxins´. These are of great concern due to their high toxicity and global spread. LÄS MER

  4. 3. Association of hydrophobic organic compounds to organic material in the soil system

    Författare :Silviu-Laurentiu Badea; Mats Tysklind; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HOCs; Organic Matter; Clay; DOM; Environmental Science; miljövetenskap;

    Sammanfattning : Contaminated soils and sediments have been identified as significant secondary sources of organic contaminants.  Leaching tests may be useful tools to estimate the mobility of contaminants via the water phase and thereby the risk for groundwater and surface water contamination. LÄS MER

  5. 4. Trace analysis of dioxins and dioxin-like PCBs using comprehensive two-dimensional gas chromatography with electron capture detection

    Författare :Conny Danielsson; Peter Haglund; Karin Wiberg; Jean-Marie Dimandja; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Comprehensive two-dimensional gas chromatography; GC × GC; µECD; PCDDs; PCDFs; dioxins; dioxin-like PCBs; Pressurized liquid extraction; PLE; PLE-C; food; feed; fly ash; soil; Environmental chemistry; Miljökemi;

    Sammanfattning : Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of struc-turally related chlorinated aromatic hydrocarbons, generally referred to as “dioxins” are of great concern due to their extreme toxicity and presence in all compartments of the environment. Since they occur at very low levels, their analysis is complex and challenging, and there is a need for cost-efficient, reliable and rapid analytical alternatives to the expensive methods in-volving use of gas chromatography high-resolution mass spectrometry (GC-HRMS). LÄS MER