Sökning: "chromatography matrices"

Visar resultat 16 - 20 av 56 avhandlingar innehållade orden chromatography matrices.

  1. 16. Aroma Partition and Release from Soft Drinks, Jam, and Jellied Sweets

    Författare :Annika Hansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gas chromatography; aroma; gel; model mouth; partition coefficient; release; citric acid; pectin; in-nose; sugar; proton-transfer reaction mass spectrometry; soft drink;

    Sammanfattning : The research described in the present thesis was focused on the influence of food ingredients and structures on the partition and release of aroma compounds from model systems such as soft drinks, jam, and jellied sweets. The effects on aroma release were studied during both static and dynamic conditions, the latter by both model mouth and in-nose measurements. LÄS MER

  3. 17. 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

  4. 18. Molecularly Imprinted Solid-Phase Extraction and Liquid Chromatography for Biological Samples

    Författare :Kristina Möller; Ulrika Nilsson; Maria Kempe; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Analytisk kemi;

    Sammanfattning : This thesis focuses on the use of molecularly imprinted polymers as selective sorbents for solid-phase extraction (MISPE). The MISPE methods developed were mainly intended for use with biological samples, such as human urine and blood plasma. LÄS MER

  5. 19. Isotope analysis of trace and ultra-trace elements in environmental matrices

    Författare :Nicola Pallavicini; Per Andersson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : High precision isotope ratio measurements have found increasing application in various branches of science, from classical isotope geochronology to complex multi-tracer experiments in environmental studies. Progress in analytical technologies in recent years has allowed higher quality data to be obtained through mass spectrometry. LÄS MER

  7. 20. Liquid chromatography-mass spectrometry in the analysis of radiolabelled compounds for positron emission tomography

    Författare :Benita Hyllbrant Forngren; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : Methods for liquid chromatography-mass spectrometry (LC/MS) with electrospray ionization (ESI) have been developed for the determination of specific radioactivity and for metabolic studies of radiolabelled compounds used in positron emission tomography (PET). These compounds often provide an analytical challenge mainly due to their low concentrations in complex sample matrices. LÄS MER