Download or read book Synthesis and Evaluation of Thermo responsive Stationary Phases for High Performance Liquid Chromatography HPLC written by Farnoosh Roohi and published by . This book was released on 2009 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Evaluation of Four Novel Stationary Phases in High Pressure Liquid Chromatography written by Niloofar Salehi and published by . This book was released on 2012 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: High pressure liquid chromatography is one of the most frequently used methods for the separation of mixtures. Chemically modified silica hydride stationary phases, due to their unique selectivity and versatility, have been the focus of an increasing number of studies in the past several years. The objective of fabricating stationary phases with dual properties is to achieve separation of both polar and non-polar components in a single analysis. Due to an increasing demand in the fields of drug discovery, proteomics, and metabolomics to analyze numerous samples with a wide range of polarities, there is a need for more versatile stationary phases for a wide range of applications. In order to meet the above objective, in this research four novel silica hydride-based columns were synthesized using a hydrosilation procedure. The characterization of each column was done using a series of polar and nonpolar compounds by studying their aqueous normal phase and reversed-phase chromatographic behavior. Under these conditions, it turned out that two columns showed both RP and ANP behaviors. Of the remaining columns, one exhibited ANP behavior only and the other performed only in the reversed-phase mode.
Download or read book Design Functionalization Synthesis and Evaluation of New Chiral Stationary Phases for U HPLC and Their Implementation in Drug Analysis enantio purification and Structural Elucidation written by Christian Geibel and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chiral liquid chromatography is a field of utmost importance for a wide range of academic and industrial applications. Drug development, environmental analysis, laboratory-based diagnostics, or structure elucidation among others, strongly rely on chiral liquid chromatography nowadays. For this reason, this cumulative thesis describes the development and applications of chiral stationary phases for enantioselective (ultra-)high performance liquid chromatography ((U)HPLC). In the first part of the thesis, new chiral stationary phases (CSPs) based on anion-exchange and zwitterionic ion exchange chiral selectors were developed. The following goals were achieved during the work on this thesis: Various silica particles were evaluated for their kinetic performance optimization for enantioselective UHPLC and a deep insight into a variety of interactions between analyte and stationary phase was gained [Publication I]. The bonding chemistry and its generation by thermic or UV-driven radical starter was evaluated and systematically optimized by introducing a solvent-free photo-click immobilization strategy resulting in low-bleeding, “platform-type” stationary phases [Publication II]. Furthermore, the functionalization of bare silica, which can be seen as the starting point of the production of a CSP-based HPLC column, was varied and optimized for fast separations by the reduction of mass transfer resistance using silatranes and thus forming thin, homogeneous monolayer of thiol functionalization in a multiple-step [Publication III] and in a single-step approach [Publication IV]. The second part of the thesis focuses on the application of enantiomer separation. This includes the elaboration of the following aspects: Since chiral methods are becoming increasingly important in the fields of metabolomics and lipidomics, a guide for the chiral analysis of branched short-chain fatty acids based on polysaccharide columns was developed [Publication V]. Furthermore, the chirality of previously unknown natural compounds was elucidated [Publication VI]. A protocol for the enantiopurification of a radiotracer was established [Publication VII]. Knowledge about chiral HPLC was used for both analytical and preparative separation in the development of potential new drugs [Publications VIII and IX]. In summary, extensive research on the design, functionalization, synthesis, and evaluation of chiral stationary phases and their scope of applications has been performed.
Download or read book The Synthesis and Evaluation of Novel Stationary Phases for Gas Chromatography written by Subhash Chandra Dhanesar and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of New Stationary Phases and Their Applications in High Performance Liquid Chromatography written by Haixiao Qiu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High performance liquid chromatography (HPLC) has proven to be the most widely applicable and versatile technique in separation science. Hydrophilic interaction liquid chromatography (HILIC) has attracted considerable interest and has become a viable option for the separation of polar compounds. Chirality is another major concern in the modern pharmaceutical industry for two reasons: 1). the majority of bio-organic molecules are chiral; 2). enantiomers of a racemic drug may often exhibit different biological activities, pharmacokinetics, and toxicities. The field of enantiomeric separations has reached a clear level of maturity after approximately 30 years of development. However, with the continued emphasis on stereochemistry in drug design and development, chiral separations are in ever increasing demand. The development of new, more effective methods is still challenging and demanding experimentally. This dissertation discusses new research in three areas: 1). Development and application of new HILIC stationary phases for the separation of polar organic compounds. Two types of new HILIC stationary phases have been successfully synthesized and evaluted. One is based on native cyclofructan 6 and another one is a zwitterionic stationary phase based on 3-P,P-diphenylphosphonium-propylsulfonate. Their performance and retention mechanisms in the HILIC mode will be discussed in this dissertation.2). Development and evaluation of new chiral stationary phases. R-naphthylethyl-carbamate cyclofructan 6 (RN-CF6) and dimethylphenyl-carbamate cyclofructan 7 (DMP-CF7) were successfully synthesized and provide enantioselectivity toward a broad range of chiral compounds. They were found to be the best aromatic-functionalized cyclofructan chiral stationary phases and provide enantiomeric separations complementary to the isopropyl-carbamate cyclofructan 6 based chiral stationary phase. This dissertation also describes method development of enantiomeric impurities quantification in chiral reagents. Three macrocyclic chiral stationary phases, including cyclodextrins, macrocyclic glycopeptides and cyclofructans, have been used to determine enantiomeric impurities in new chiral catalysts, auxiliaries and synthons used in asymmetric syntheses. It was found that many of the newer chiral reagents are highly enantiopure, probably due to continual improvements in asymmetric syntheses and purification in the manufacturing process. 3). Development and application of new stationary phases based on a resin substrate instead of silica gel. This dissertation describes methods for binding cyclofructan 6 to resin via "click" chemistry. It was found that these resin based stationary phases appear to have potential in HILIC separations (native cyclofructan 6 bonded to resin as stationary phases) and enantiomeric separations (isopropyl-carbamated cyclofructan 6 bonded to resin).
Download or read book Synthesis and Evaluation of Liquid Organic Salts as Stationary Phases for Gas Chromatography written by Rena M. Pomaville and published by . This book was released on 1989 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Evaluation of New Chiral Phases for High Performance Liquid Chromatography written by William Garrick Etherington and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Characterization of Bonded Stationary Phases in High Performance Liquid Chromatography written by Steven Douglas Fazio and published by . This book was released on 1985 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Evaluation of Novel Polymeric Stationary Phases for Capillary Liquid Chromatography and Electrochromatography written by Zhixin Jessica Tan and published by . This book was released on 1998 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High temperature Liquid Chromatography written by Thorsten Teutenberg and published by Royal Society of Chemistry. This book was released on 2010 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-temperature liquid chromatography has attracted much interest in recent years but has not yet recognized its full potential in the chromatographic community. There is a widespread reluctance in industry to use temperature to speed up the separation process, influence the selectivity of a separation or implement novel detection techniques. However, the technology has now matured and could revolutionize chromatography as we see it today. Better equipment, such as heating systems able to generate faster heating rates, is becoming more readily available. Also, columns based on silica gel, which can withstand higher temperatures for an extended period, are now being introduced. Nevertheless, further technological and methodical efforts are needed to establish the method in a regulated environment like the pharmaceutical industry. This is the only text to cover all the practical aspects, as well as the underlying theoretical principles, of setting up an HPLC system for high-temperature operation. It is not intended solely for academics but will also benefit the researcher interested in more practical considerations. The author is a recognized expert and has conducted several studies with partners from industry to validate the method. Many real examples from these studies have been included in the book. The aim is to support practitioners in the creation of their own protocols without the need to rely solely on trial and error. The book starts with a brief definition of high-temperature liquid chromatography before going on to cover: system set up; the heating system; mobile phase considerations; suitable stationary phases; method development using temperature programming; analyte stability, and special hyphenation techniques using superheated water as a mobile phase. In each chapter, experimental data is used to illustrate the main statements and the advantages over conventional HPLC are evaluated. The book concludes with a critical outlook on further developments and applications underlining the necessary advances needed to make high-temperature HPLC more robust.
Download or read book Synthesis and Characterization of Surface confined Ionic Liquid Stationary Phases for High Performance Liquid Chromatography written by David S. Van Meter (III.) and published by . This book was released on 2008 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Summary of Progress Toward the Synthesis of New Chiral Stationary Phases for High Performance Liquid Chromatography written by David B. Rusterholz and published by . This book was released on 1985 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Characterization of Bonded Zwitterionic Stationary Phases for High Performance Liquid Chromatography written by Louis W. Yu and published by . This book was released on 1987 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Liquid Crystal like Stationary Phases for High Performance Liquid Chromatography written by Zhuxu Wang and published by . This book was released on 1995 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Chromatography written by Salvatore Fanali and published by Elsevier. This book was released on 2017-06-23 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid Chromatography: Applications, Second Edition,is a single source of authoritative information on all aspects of the practice of modern liquid chromatography. It gives those working in both academia and industry the opportunity to learn, refresh, and deepen their knowledge of the wide variety of applications in the field. In the years since the first edition was published, thousands of papers have been released on new achievements in liquid chromatography, including the development of new stationary phases, improvement of instrumentation, development of theory, and new applications in biomedicine, metabolomics, proteomics, foodomics, pharmaceuticals, and more. This second edition addresses these new developments with updated chapters from the most expert researchers in the field. Emphasizes the integration of chromatographic methods and sample preparation Explains how liquid chromatography is used in different industrial sectors Covers the most interesting and valuable applications in different fields, e.g., proteomic, metabolomics, foodomics, pollutants and contaminants, and drug analysis (forensic, toxicological, pharmaceutical, biomedical) Includes references and tables with commonly used data to facilitate research, practical work, comparison of results, and decision-making
Download or read book The Synthesis and Characterization of Reversed Phase Stationery Phases for High Performance Liquid Chromatography written by Karen Wink Barnes and published by . This book was released on 1986 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Synthesis and Evaluation of Selectors and Stationary Phases for Improved Liquid Chromatographic Separations written by Christopher J. Welch and published by . This book was released on 1992 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study a diverse array of research projects are presented, all having to do with the development of selectors and stationary phases for improved liquid chromatographic separations. Apart from the introductory material, two main topics are addressed: (1) the role of non-specific adsorption in chromatographic separations, and (2) the synthesis of selectors designed for recognition of particular analyte molecules. In the introductory part of the thesis the use of 1,3,5-tri-t-butylbenzene as an improved void volume marker for several chiral stationary phases (CSPs) is described, as is a thermodynamic study investigating the role of solvation in a well characterized chiral recognition system. The role of non-specific adsorption in chromatographic separations has been addressed for both the analyte and the stationary phase. A study of the effect of superfluous remote polar functionality on chiral recognition shows that polar groups not required in the chiral recognition process can have a deleterious effect on enantiomer separations by increasing retention and sometimes reducing enantioselectivity. The preparation of CSPs in which nonessential interaction sites have been eliminated leads to CSPs showing reduced retention and increased enantioselectivity. An improved CSP designed for the non-steroidal anti-inflammatory drug, naproxen, is described in-five different studies. A "reciprocal" approach was used in this study, (S)-naproxen being immobilized to produce a CSP which was used to screen potential naproxen selectors. This study revealed several key features important for the enantioselective recognition of naproxen, which were incorporated inio a novel selector and CSP displaying a high degree of enantioselectivity for underivatized naproxen. The underivatized enantiomers of a number of related drugs such as ibuprofen, ketoprofen, etc. are easily separable using this CSP. Finally, the rational design of an improved selector and stationary phase for the carbon cluster buckminsterfullerene (C$sb{60}$) is described. A tripodal selector containing three $pi$-acidic aromatic rings for simultaneous multipoint interaction with the spherical analyte molecule was immobilized on silica to afford a stationary phase displaying a high degree of retention for buckminsterfullerene, and a large separation factor for separation of the C$sb{60}$/C$sb{70}$ mixture.
