Sökning: "Hyphenated system"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Hyphenated system.

1. 1. Large Volume Injection and Hyphenated Techniques for Gas Chromatographic Determination of PBDEs and Carbazoles in Air

   Författare :Petter Tollbäck; Conny Östman; Tuulia Hyötyläinen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; large volume injection; hyphenated techniques; LC-GC; GC-MS; mass spectrometry; GC; gas chromatography; carbazoles; PBDE; polybrominated diphenyl ethers; Analytical chemistry; Analytisk kemi;

   Sammanfattning : This thesis is based on studies in which the suitability of various gas chromatography (GC) injection techniques was examined for the determination of polybrominated diphenyl ethers (PBDEs) and carbazoles, two groups of compounds that are thermally labile and/or have high boiling-points. For such substances, it is essential to introduce the samples into the GC system in an appropriate way to avoid degradation and other potential problems. LÄS MER

3. 2. Pressurised Fluid Extraction of Bioactive Species in Tree Barks : Analysis using Hyphenated Electrochemical Mass Spectrometric Detection

   Författare :Michelle Co; Charlotta Turner; Per J.R Sjöberg; Kari Hartonen; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pressurised fluid extraction; antioxidants; DPPH; water; ethanol; antioxidant activity; antioxidant capacity; electrochemial detection; mass spektrometry; Chemistry; Kemi; Analytical Chemistry; Analytisk kemi;

   Sammanfattning : Analytical chemistry has developed throughout time to meet current needs. At present, the interest in biorefinery is growing, due to environmental awareness and the depletion of fossil resources. Biomass from agricultural and forestry industries has proven to be excellent raw material for different processes. LÄS MER

4. 3. On the reliability of methods for the speciation of mercury based on chromatographic separation coupled to atomic spectrometric detection

   Författare :Johanna Qvarnström; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Mercury; speciation; hyphenated techniques; HPLC; CE; GC; CV-AAS; ICP-MS; species-specific enriched stable isotope; Analytisk kemi; Analytical chemistry; Analytisk kemi; analytisk kemi; Analytical Chemistry;

   Sammanfattning : This thesis deals with the reliability of methods for the speciation of mercury in environmental and biological samples. Problems with speciation methods that couple chromatography to atomic spectrometric detection and how to overcome the problems are discussed. LÄS MER

5. 4. Novel on-line mid infrared detection strategies in capillary electrophoretic systems

   Författare :Malin Kölhed; Bo Karlberg; Sven P. Jacobsson; Andre' J. Sommer; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; on-line hyphenation; mid infrared detection; capillary electrophoresis; FTIR; quantum cascade laser; aqueous samples; Analytical chemistry; Analytisk kemi;

   Sammanfattning : Infrared absorption spectra can provide analytically useful information on a large variety of compounds, ranging from small ions to large biological molecules. In fact, all analytes that possess a dipole moment that changes during vibration are infrared-active. The infrared (IR) spectrum can be subdivided into far-, mid- and near- regions. LÄS MER

7. 5. Development of Methods for the Analysis of Polar Compounds in Environmental Matrices using LC/UV and LC/MS

   Författare :Johanna Minten; Margaretha Adolfsson-Erici; Leif Kronberg; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : In recent years, the awareness of environmentally hazardous compounds with polar and ionizable properties has intensified. Pharmaceuticals, the pesticide tebuconazole as well as the artificial sweetener sucralose are examples of such new, emerging, contaminants. LÄS MER