Sökning: "Analytisk kemi"
Visar resultat 36 - 40 av 601 avhandlingar innehållade orden Analytisk kemi.
36. Novel clean-up, concentration and laser desorption/ionization strategies for mass spectrometry
Sammanfattning : Despite valuable advantages of mass spectrometry (MS) techniques they still have drawbacks that need to be overcome, notably their sensitivity to various kinds of interfering substances and associated difficulties involved in detecting signals from analytes present in trace quantities. Thus, high quality analytical data could be acquired by improving sample pre-treatment techniques and/or ionization methods to increase ionization yields and/or avoid the generation of unwanted ions. LÄS MER
37. Mass Spectrometry of Biologically Active Small Molecules : Focusing on polyphenols, alkaloids and amino acids
Sammanfattning : The foci of this dissertation are on advanced liquid chromatography (LC) separation and mass spectrometry (MS) techniques for the analysis of small bioactive molecules. In addition to discussing general aspects of such techniques the results from analyses of polyphenols (PPs), alkaloids and amino acids published in five appended studies are presented and discussed. LÄS MER
38. Colloidal/Solid Phase Extraction (C/S PE) Methods Based on Hydrogel Nanoparticles, Titanium dioxide microparticles and Empore Membranes Applied to Biological and Environmental Matrices
Sammanfattning : The aim of the work described in this thesis was to create and develop novel technologies in order to overcome barriers and hurdles that analytical chemistry faces focusing on sample extraction. In paper I dye containing amine groups (e.g. LÄS MER
39. Retention time predictions in Gas Chromatography
Sammanfattning : In gas chromatography, analytes are separated by differences in their partition between a mobile phase and a stationary phase. Temperature-program, column dimensions, stationary and mobile phases, and flow rate are all parameters that can affect the quality of the separation in gas chromatography. LÄS MER
40. New methods for determination of airborne pollutants : Focus on tetrabromobisphenol A, organophosphate triesters and polycyclic aromatic hydrocarbons
Sammanfattning : The work presented in this thesis concerns the development and evaluation of new methods of sampling and analysis of organic pollutants in the indoor and outdoor environment. In Paper I, the development of a new method was reported for the determination of the brominated flame retardant tetrabromobisphenol A (TBBPA) in air using sampling with glass fiber filter and polyurethane foam (PUF), ultrasonic solvent extraction and liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI/MS). LÄS MER