Search for dissertations about: "mass spektrometri"

Showing result 1 - 5 of 14 swedish dissertations containing the words mass spektrometri.

  2. 1. Aspects of Porous Graphitic Carbon as Packing Material in Capillary Liquid Chromatography

    Author : Anna Törnkvist; Wolfgang Lindner; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; PGC; porous graphitic carbon; stationary phase; packing material; LC; liquid chromatography; miniaturized; chiral; enantiomer; ESI; electrospray ionization; mass spectrometry; polar compounds; L-DOPA; dopamine; biological samples; biological matrix; Analytisk kemi; PGC; poröst grafitiserat kol; stationärfas; packningsmaterial; LC; vätskekromatografi; miniatyriserade system; kiral; enantiomer; ESI; electrospray jonisation; mass spektrometri; polära föreningar; L-DOPA; dopmamine; biologiska prover; biologisk matris; Analytical chemistry; Analytisk kemi; Analytical Chemistry; Analytisk kemi;

    Abstract : In this thesis, porous graphitic carbon (PGC) has been used as packing material in packed capillary liquid chromatography. The unique chromatographic properties of PGC has been studied in some detail and applied to different analytical challenges using both electrospray ionization-mass spectrometry (ESI-MS) and ultra violet (UV) absorbance detection. READ MORE

  4. 2. Biokinetics and radiation dosimetry of 14C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine “breath tests” using accelerator mass spectrometry

    Author : Mikael Gunnarsson; Malmö Medicinsk strålningsfysik; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering; Kärnfysik; Nuclear physics; xylose.; glycocholic acid; urea; triolein; Dosimetry; Biokinetic; AMS; Accelerator mass spectrometry; 14C; Breath test;

    Abstract : 14C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. READ MORE

  5. 3. Improvement of the AMS-technique and applications to 3H and 59Ni Measurements

    Author : Madis Kiisk; Kärnfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; accelerator mass spectrometry AMS ; development of AMS technique; 59Ni; tritium; Kärnfysik; Nuclear physics; Fysicumarkivet A:2003:Kiisk;

    Abstract : Accelerator mass spectrometry (AMS) is a highly sensitive technique for counting atoms. Its main advantage in comparison with radiometric methods is the smaller amount of sample required (by a factor of a thousand). The method has a high efficiency and requires only some ten mg of sample material. READ MORE

  6. 4. Single fluid inclusion analysis using ToF-SIMS : Implications for ancient Earth biodiversiy and paleoenvironment studies

    Author : Sandra Siljeström; Jukka Lausmaa; Andrew Steele; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ToF-SIMS; time-of-flight secondary ion mass spectrometry; fluid inclusions; biomarkers; hopanes; steranes; early life; paleoenvironment; oil; eukaryotes; Earth sciences; Geovetenskap; geokemi; Geochemistry;

    Abstract : When and how life first emerged on the Earth is an area of intense research. Signs of the first life on Earth, including morphological fossils, are scarce and hard to interpret. An alternative approach is to study organic biomarkers, which are molecular fossils commonly considered as bona fide biosignatures. READ MORE

  7. 5. Tuning the polylactide hydrolysis rate without introducing new migrants

    Author : Sofia Regnell Andersson; Minna Hakkarainen; Karin Jacobson; Ulrika Edlund; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; polylactide; sterocomplex; plasticizer; degradation; degradation products; ESI-MS; Biochemistry; Biokemi; Polymer chemistry; Polymerkemi;

    Abstract : The possibility to control and tune the hydrolytic degradation rate of polylactide without introducing any new degradation products was investigated by subjecting polylactide with cyclic or linear oligolactic acid additives, and a stereocomplex between the L- and D-enantiomers of polylactide to hydrolytic degradation at 37 and 60 °C for up to 39 weeks. The degradation was monitored by measuring mass loss, molar mass changes, water uptake, changes of surface structure, crystallinity and thermal properties. READ MORE