Sökning: "GC"

Visar resultat 11 - 15 av 403 avhandlingar innehållade ordet GC.

  1. 11. Alkylation and Hydrodearomatization over Zeolite cCatalysts

    Författare :Jun-Jun Yuan; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acid catalysts; ZSM-5 catalysts; ethylbenzene; toluene; temperature; diesel fuel; hydrodearomatization; benzene; acidic protons; activity and selectivity; aqueous ethanol; Pt Y zeolite; gasoline; pressure; GC; diethylbenzene; Hydrocracking; SiO2 Al2O3 ratio; alkylation of aromatics; Brønsted acids;

    Sammanfattning : The alkylation of aromatic compounds is widely used in the large-scale synthesis of petrochemicals, and a great variety of fine chemicals and intermediates. Acid catalysts used for alkylation of aromatic hydrocarbons are Brønsted acids containing acidic protons. LÄS MER

  3. 12. Strategies for Monitoring of Endocrine Disrupting Chemicals in Aquatic Environment

    Författare :Pär Hallgren; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; vitellogenin; Endocrine disruption; alkali-labile phosphate; Carassius carassius; steroid hormones; Oncorhynchus mykiss; membrane exraction; supercritical fluid extraction; GC;

    Sammanfattning : The protein biomarker vitellogenin in fish is discussed alongside alterative strategies for monitoring of endocrine disrupting chemicals. The first objective was to find a cheap, robust and generic method for the quantification of vitellogenin. LÄS MER

  4. 13. Alkylation of benzene/ethanol and toluene/methanol over ZSM-5

    Författare :Junjun Yuan; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; alkylation of aromatics; benzene; xylene isomers; toluene; ethanol; zeolites; ethylbenzene; Bronsted acids; acid catalysts; GC; SiO2 Al2O3; acidic protons; ration; activity and selectivity;

    Sammanfattning : .... LÄS MER

  5. 14. Methods for Determination of Benzo(a)pyrene and High Molecular Weight (>300 Da) Polycyclic Aromatic Hydrocarbons in Particulate Matter from Ambient Air and Vehicle Exhausts

    Författare :Christoffer Bergvall; Roger Westerholm; Stephen Wise; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PAH; dibenzopyrene; benzo a pyrene; standard reference material; air particulate matter; diesel particulate matter; toxic equivalence factor; ultrasonic assisted extraction; accelerated solvent extraction; automation; online coupling; GC MC; LC GC MS; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : Air pollution with particulate matter (PM) raises considerable concern because of its adverse effects on human health. For this reason, and because the mechanisms of PM toxicity are not fully known, there is an urgent need to determine the chemical constituents of atmospheric PM, especially PM emanating from traffic - a major source of urban PM. LÄS MER

  7. 15. 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