Sökning: "GC"

Visar resultat 16 - 20 av 403 avhandlingar innehållade ordet GC.

  1. 16. Aroma characterisation and retention after heat treatment and drying of fruits using extraction and GC-MS analysis

    Författare :Rui Ráice; Livsmedelsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fruits; Vangueria infausta; Mangifera indica; volatile; aroma; blanching; drying; encapsulation; modelling; GC-MS.;

    Sammanfattning : This study concerns the identification and characterisation of volatile components of fruits, and evaluation of the effect of heat treatment and drying on retention or loss of volatiles of fruits. The investigation included developing a procedure to extract volatile components from the fruit matrix, a purification step, separation, identification and quantification. LÄS MER

  3. 17. Targeted and untargeted analysis of organic contaminants from on-site sewage treatment facilities : Removal, fate and environmental impact

    Författare :Kristin Blum; Peter Haglund; Patrik Andersson; Pim Leonards; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; decentralized sewage treatment; wastewater; surface water; environmental fate; bioavailability; removal efficiency; mass fluxes; biochar; environment; GC×GC-MS; LC-IM-MS; mass spectrometry; contaminants; pollutants; prioritization; non-target analysis; screening; analytisk kemi; Analytical Chemistry;

    Sammanfattning : On-site sewage treatment facilities (OSSFs) are widely used all over the world to treat wastewater when large-scale sewage treatment plants (STPs) are not economically feasible. Although there is great awareness that the release of untreated wastewater into the environment can lead to water-related diseases and eutrophication, little is known about organic contaminants and their removal by OSSFs, environmental load and fate. LÄS MER

  4. 18. 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

  5. 19. Combustion Chemistry Investigation of Liquid and Solid Fuels

    Författare :Åsa Håkansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gasoline; flame; GC MS; heptane; combustion; pyrolysis; kinetics; emissions; wood; RME;

    Sammanfattning : The aim of this work was to study the combustion of liquid and solid fuels with the emphasis on intermediates and products. Depending on the structure and the complexity of the fuel different reactors and methods were used. Small-scale laboratory reactors were built and chemical analysis and evaluation methods were developed. Heptane. LÄS MER

  7. 20. Microorganisms in indoor environments. A search for health-related measurements

    Författare :Loay Wady; Avdelningen för medicinsk mikrobiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mykologi; virologi; bakteriologi; Mikrobiologi; mycology; bacteriology; virology; Microbiology; schools; microbial markers; MVOCs; building materials; dust; GC MSMS; SPME;

    Sammanfattning : Microorganisms are ubiquitous in indoor air and epidemiological data suggest that inhalation of microbes and/or their products adhered on air–borne dust particles can impair well–being and health. In the present thesis microbial volatile organic compounds (MVOCs) and cellular markers were studied by gas chromatography–mass spectrometry (GC/MS). LÄS MER