Search for dissertations about: "HILIC"

Showing result 1 - 5 of 11 swedish dissertations containing the word HILIC.

2. 1. Hydrophilic Separation Materials for Liquid Chromatography

   Author : Petrus Hemström; Knut Irgum; Peter Schoenmakers; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chromatography; HILIC; Hydrophilic; Stationary phase; Chemistry; Kemi;

   Abstract : The main focus of this thesis is on hydrophilic interaction chromatography (HILIC) and the preparation of stationary phases for HILIC. The mechanism of HILIC is also discussed; a large part of the discussion has been adapted from a review written by me and professor Irgum for the Journal of Separation Science (ref 34). READ MORE

4. 2. Study of retention mechanisms in Hydrophilic Interaction Chromatography by Nuclear Magnetic Resonance Spectroscopy

   Author : Adel Shamshir; Knut Irgum; Tobias Jonsson; Ngoc Phuoc Dinh; Torgny Fornstedt; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; HILIC; hydrophilic interaction chromatography; adsorption; STD-NMR; saturation transfer difference; retention mechanism; NMRD; solid state-NMR; Analytical Chemistry; analytisk kemi;

   Abstract : This thesis deals with investigations of the retention mechanisms in hydrophilic interaction liquid chromatography (HILIC) using nuclear magnetic resonance spectroscopy. The aims are to understand how the different types of stationary phases can influence the retention of various solutes and the adsorption abilities of solvent on stationary phases. READ MORE

5. 3. Investigations of the retention mechanisms in hydrophilic interaction chromatography

   Author : Ngoc Phuoc Dinh; Knut Irgum; Andrew J. Alpert; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; HILIC; hydrophilic interaction chromatography; adsorption isotherm; water enriched layer; multivariate data analysis; retention mechanism; separation; analytisk kemi; Analytical Chemistry;

   Abstract : Hydrophilic interaction chromatography is well known as a powerful technique separation of polar and ionizable compound nowadays. However the retention mechanism of the technique is still under debate. Understanding retention mechanism would facilitate the method development using the technique and its future improvement. READ MORE

6. 4. Polyhydroxyl and Polyphosphorylcholine functionalized Silica for Hydrophilic interaction liquid Chromatography- Synthesis, characterization and application

   Author : Nhat Thi Hong Bui; Knut Irgum; Michael Lämmerhofer; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Hydrophilic Interaction Chromatography; HILIC; silica; TRIS; acrylamide acrylate; ATRP; iniferter; “controlled living’’ radical polymerization; N; N′-methylenebisacrylamide; MPC; stationary phase; analytisk kemi; Analytical Chemistry;

   Abstract : This thesis focuses on the development of new stationary phases for use in hydrophilic interaction liquid chromatography using TRIS-based and phosphorylcholine typed monomers and porous silica particles as starting substrates. In this thesis, several ways of polymerizing highly hydrophilic mono­mers onto pore surfaces of silica supports are described, based on several “grafting from” schemes. READ MORE

7. 5. Selectivity in NMR and LC-MS Metabolomics : The Importance of Sample Preparation and Separation, and how to Measure Selectivity in LC-MS Metabolomics

   Author : Albert Elmsjö; Curt Pettersson; Torbjörn Arvidsson; Thomas Moritz; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Metabolomics; NMR; LC-MS; HILIC; UHPLC; Q-ToF; selectivity; co-feature ratio; method evaluation; data evaluation; Analytical Pharmaceutical Chemistry; Analytisk farmaceutisk kemi;

   Abstract : Until now, most metabolomics protocols have been optimized towards high sample throughput and high metabolite coverage, parameters considered to be highly important for identifying influenced biological pathways and to generate as many potential biomarkers as possible. From an analytical point of view this can be troubling, as neither sample throughput nor the number of signals relates to actual quality of the detected signals/metabolites. READ MORE