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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Utveckling av LC-MS metod för kvantitativ analys av metadon och dess huvudmetabolit EDDP i urin

Norberg, Fredrik January 2014 (has links)
No description available.
2

Identification of antistatic/antifogging agents in polymers, including used plastic packaging / Identifiering av antistatiska och antifogging additiv i polymerer, inklusive använda plastförpackningar

Lund, Rebecka, Ibrahim, Raam, Johansson, Emil January 2021 (has links)
Huvudmålet i projektet var att analysera det vanligt förekommande additivet glycerolmonostearat, GMS, i plastprover. Projektet är en del av ett samarbete mellan KTH och det norska företaget Norner. Projektgruppen har jobbat för att utvärdera och optimera företagets nuvarande analysmetod samt att identifiera glycerolmonostearat i polypropylen. Olika lösningsmedel och derivatiseringsreagens testades, såväl som olika temperaturprofiler, för gaskromatografen jämfördes under projektet. Resultaten visade att glycerolmonostearat kunde derivatiseras genom silylering. Alla prover har sammanfattats i en slutgiltig metod som är lämpad för analys av polyolefiner som innehåller glycerolmonostearat. Slutmetoden saknade möjligheten för kvantitativ analys och kan därför förbättras i framtiden. / The main task was to analyze the very common additive, glycerol monostearate, GMS in plastic samples. The project was a collaboration between KTH students and the Norwegian company Norner. The goal was to evaluate and optimize the company's current method of analysis and identification of the content of GMS in polyolefins. Different solvents, derivatization agents and methods for gas chromatography were compared to find an effective process by which additives in polypropylene samples can be analyzed. The results showed that glycerol monostearate can be derivatized through a process called silylation. All different attempts have been summarized into one final method that was most suitable for the analysis of polyolefins containing glycerol monostearate. The final method was reproducible but lacked a properly determined quantification analysis. The final method can be improved further after this project. To give a few examples there are a lot more potential derivatization agents and solvents that can be substituted which requires further research.
3

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

Törnkvist, Anna January 2003 (has links)
<p>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. </p><p>The crucial importance of disengaging the conductive PGC chromatographic separation media from the high voltage mass spectrometric interface has been shown. In the absence of a grounded point between the column and ESI emitter, a current through the column was present, and changed retention behaviors for 3-O-methyl-DOPA and tyrosine were observed. An alteration of the chromatographic properties was also seen when PGC was chemically oxidized with permanganate, possibly due to an oxidation of the few surface groups present on the PGC material. </p><p>The dynamic adsorption of the chiral selector lasalocid onto the PGC support resulted in a useful and stable chiral stationary phase. Extraordinary enantioselectivity was observed for 1-(1-naphthyl)ethylamine, and enantioseparation was also achieved for other amines, amino acids, acids and alcohols. </p><p>Finally, a new strategy for separation of small biologically active compounds in plasma and brain tissue has been developed. With PGC as stationary phase it was possible to utilize a mobile phase of high content of organic modifier, without the addition of ion-pairing agents, and still selectively separate the analytes. </p>
4

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

Törnkvist, Anna January 2003 (has links)
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. The crucial importance of disengaging the conductive PGC chromatographic separation media from the high voltage mass spectrometric interface has been shown. In the absence of a grounded point between the column and ESI emitter, a current through the column was present, and changed retention behaviors for 3-O-methyl-DOPA and tyrosine were observed. An alteration of the chromatographic properties was also seen when PGC was chemically oxidized with permanganate, possibly due to an oxidation of the few surface groups present on the PGC material. The dynamic adsorption of the chiral selector lasalocid onto the PGC support resulted in a useful and stable chiral stationary phase. Extraordinary enantioselectivity was observed for 1-(1-naphthyl)ethylamine, and enantioseparation was also achieved for other amines, amino acids, acids and alcohols. Finally, a new strategy for separation of small biologically active compounds in plasma and brain tissue has been developed. With PGC as stationary phase it was possible to utilize a mobile phase of high content of organic modifier, without the addition of ion-pairing agents, and still selectively separate the analytes.

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