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 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 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 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 Enantioselective Synthesis Enantiomeric Separations and Chiral Recognition written by Maria Elizabeth Tiritan and published by MDPI. This book was released on 2020-11-13 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes both fundamental studies and applications in a multidisciplinary research field involving a high diversity of chiral compounds, including commercial substances with industrial applications, pharmaceuticals, and new chiral compounds with promising biological activities.
Download or read book A Summary of Progress Toward the Design and Synthesis of New Chiral Stationary Phases for High Performance Liquid Chromatography II Target Compounds Based on Natural Amino Acids written by David Billing Rusterholz and published by . This book was released on 1986 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Chiral Separations written by D. Stevenson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume represents the proceedings of a two-day international meeting on chiral chromatography held at the University of Surrey between 3-4 September 1987. The meeting was jointly organized by the Chromatographic SOCiety and the Robens Institute of the University of Surrey in response to the burgeoning interest in this rapid maturing field of chromatography. Nowhere is this interest more evident than in the agrochemical and pharmaceutical industries where the implications of different pharmacological and toxicological activity for the individual enantiomers present in a racemic drug ol" insecticide is an increasing area of concern. Developments in the area of chiral separations are at last beginning to provide SCientists with the necessary tools to study how animals and man handle racemates and relate their obseIVations to the obseIVed biological effects of these substances. The development of robust and Simple methods for the separation of enantiomers will therefore have a profound Impact on safety evaluation and drug design. The meeting proved to be very successful. with over 160 delegates from thirteen countries in Europe and America present to learn from the experiences of experts in the field of chiral chromatography and to hear about the latest developments. Hopefully. in future symposia on chiral separations at the University of Surrey.
Download or read book Synthesis Potentiometric Analysis and Reversed phase High performance Liquid Chromatography of New Hydroxamic Acid Reagents written by Nuala Ni Choileain and published by . This book was released on 1987 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of New Chiral Gas Chromatographic Stationary Phases with Novel Selectivities written by Aroonsiri Shitangkoon and published by . This book was released on 1995 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Chiral Stationary Phases for High Performance Liquid Chromatographic Fractionation of Racemates written by Tau-Being Thomas Hsu and published by . This book was released on 1986 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Liquid Chromatography and Subcritical Fluid Chromatography for Chiral Seperations Using Macrocyclic Chiral Stationary Phases written by Ross Michael Woods and published by . This book was released on 2014 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enantiomeric separations are an essential component of pharmaceutical drug development, not only at the analytical scale, but also to separate usable quantities for further analysis. The field of asymmetric synthesis is also heavily dependent on chromatographic methods to separate and quantitate the results of asymmetric transformations as well as characterize new ligands and catalysts. This dissertation focuses on the use of macrocyclic chiral stationary phases for use in high performance liquid chromatography as well as subcritical fluid chromatography to separate individual enantiomers of molecules of importance to the scientific community. Optimized separation conditions are provided for many of these important analytes, which will expedite the evaluation of their usefulness in a variety of applications. Particular emphasis is put on elucidating the mechanism of interaction between analyte and stationary phase. In chapters two and three, principle component analysis is applied to the chromatographic data to gain better understanding of the factors contributing to retention and enantioselectivity. It was shown that optimized separation conditions are also provided for newly synthesized isochromene and Tröger base derivatives using cyclodextrin and cyclofructan based chiral stationary phases. The fourth chapter provides separation conditions for a variety of novel synthetic biaryl atropisomers, which have the potential to serve as useful ligands in asymmetric transformations as well as possessing antibiotic/antimicrobial properties. Preparative scale separation conditions are also provided allowing for these important analytes to be prepared and evaluated in their enantiomerically pure form. Insight into the mechanism of analyte retention is provided indicating that dipolarity/polarizability is the primary retentive interaction between substituted biaryls and derivatized cyclofructans. Chapter five provided a valuable comparison of commonly used chromatographic conditions for the separation of primary amines using cyclofructan based chiral stationary phases. The effect of various addivies and polar modifiers was investigated and the results indicate that a combination of acidic and basic additives is necessary to obtain optimal separations. The advantages of individual chromatographic modes are also provided. Normal phase separations provided the greatest selectivities at the cost of longer analysis times while modified carbon dioxide mobile phases provided excellent peak profiles and short analysis times. Preparative scale separations are also provided using modified carbon dioxide mobile phases allowing for enantiopure compounds to be prepared in an environmentally friendly manner without the use of petroleum based solvents.
Download or read book Chiroptical Spectroscopy written by Prasad L. Polavarapu and published by CRC Press. This book was released on 2016-10-03 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details chiroptical spectroscopic methods: electronic circular dichroism (ECD), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and vibrational Raman optical activity (VROA). For each technique, the text presents experimental methods for measurements and theoretical methods for analyzing the experimental data. It also includes a set of experiments that can be adopted for undergraduate teaching laboratories. Each chapter is written in an easy-to-follow format for novice readers, with necessary theoretical formalism in appendices for advanced readers.
Download or read book Chiral Liquid Chromatography written by w Lough and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: While working as a chromatographer in the pharmaceutical industry, it became apparent to the editor that there was a pressing need for a comprehensive reference text for analysts working on the resolution of enantiomers by liquid chromatography (LC). This need arises from the fact that, whereas previously it was very difficult to determine enantiomers by direct means, there is now a wide choice of direct LC methods. At the same time, regulatory authorities have been changing their attitudes towards the administration of pharmaceuticals as racemates, partly because it is now possible to study the individual enantiomers. Clearly this abundance of new information needs to be rationalized. More importantly, the chiral LC systems which are commercially available or readily accessible to the practising chromatographer needed to be reviewed and, to a much greater extent than in existing reviews or books, discussed in terms of their practical application. Accordingly this book is very much orientated towards the practical aspects of these commercially available and readily accessible chiral LC systems. To this end, it is written for practising chromatographers by a team of practising, experienced chromatographers who have spent many years tackling the problems presented by resolving enantiomers by LC. The practical aspects of common chiral LC systems cannot be fully understood if discussed in isolation.
Download or read book Development of a New Polysaccharide Based Chiral Stationary Phase for High Performance Liquid Chromatography written by Jeffry J. Lynch and published by . This book was released on 1994 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chiral Separations written by Gerald Gübitz and published by Springer Science & Business Media. This book was released on 2008-02-02 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prominent experts from around the world detail the chromatographic and electroseparation techniques they have developed for chiral separations on an analytical scale. Described in step-by-step detail to ensure successful experimental results, the procedures are presented as either general methods or as specific applications to substance classes and special compounds, with emphasis on high performance liquid chromatography and capillary electrophoresis techniques, but also including thin layer chromotographic, gas chromatographic, supercritical fluid chromatographic as well as recent electrochromotographic techniques.
Download or read book Analytical Separation Science 5 Volume Set written by Jared Anderson and published by John Wiley & Sons. This book was released on 2016-02-29 with total page 2148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Endlich ein Forschungsleitfaden für Wissenschaftler des Fachgebiets, die neue Methoden entwickeln oder einsetzen. Dieses Handbuch umfasst fünf thematische Bände und bietet damit einen umfassenden Überblick über das Fachgebiet. Erläutert werden Grundlagen, die Methodenentwicklung und hochkarätige Anwendungen für alle wichtigen Analyseverfahren, darunter chromatische Verfahren, Techniken in den Bereichen Elektromigration und Membranen. Dieses Referenzwerk umfasst ein breites Spektrum und legt den Schwerpunkt auf Entwicklungen für die Zukunft. Damit ist es ein Muss für Forscher und eine wertvolle Wissensquelle für Studenten im Hauptstudium und Studienabsolventen.
