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 Chiral Chromatography written by Thomas E. Beesley and published by John Wiley & Sons. This book was released on 1999-01-26 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eine Ergänzung anderer, in der Reihe Separation Sciences bereits erschienener Titel. Viel Theorie und zahlreiche Anwendungsbeispiele für die Praxis der chiralen HPLC- und GC-Trennung machen dieses top-aktuelle Buch zu einer unverzichtbaren Informationsquelle für jeden Neueinsteiger auf diesem Gebiet. (11/98)
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 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 The Synthesis and Characterization of Reversed Phase Stationary Phases for High Performance Liquid Chromatography written by Karen Wink Barnes and published by . This book was released on 1986 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reversed phase liquid chromatography (RPLC) is a widely used separation technique today. The stationary phase, composed of hydrocarbon moieties chemically bound to a silica support, is commonly prepared by refluxing the silica with a reactive silane in an appropriate solvent. Siloxane bonds, Si-O-Si, are formed. There are limitations to RPLC in that nonhomogeneous surface coverages, detrimental to efficient separations, result from the bonding process, and because the reaction is never complete due to steric restrictions. Also, silica is soluble at high pH values, and the Si-C bond binding the hydrocarbon to the silica is labile at low pH ranges. Thus, the usable pH range for silica stationary phases is 2.5 to 7.5, and often this range is too narrow to allow the separation of a mixture. The use of ultrasonic cavitation to catalyze silane bonding was investigated to dtermine whether the vigorous ultrasonic process would drive reagents into the surface pores and better distribute the hydrocar bonaceous reagent, thereby producing a more efficient stationary phase. Tandem reactions proved that ultrasonic bonding procedures are as effective as the refluxed, and that the chromatographic efficiency of the ultrasonic phases was comparable, if not superior, to the refluxed. Chromatographic tests also indicated the ultrasonic phases were comparable to commercially available phases. The reproducibility of the reactions and the effect of acoustic power and heat were also investigated. A second set of experiments investigated substitution of alumina for silica because the alumina crystalline structure remains intact over a pH range of 2 to 12. A trifunctional modification scheme generating a thick cross-linked hydrocarbon matte was used because the Al-0 bond is susceptible to hydrolysis, which strips the bound hydrocarbons, by polar RP solvents. Five aluminas were bonded and tested for chromatographic utility. Reaction conditions were optimized, and ultrasonic bonding was investigated. It was found that alumina with a sufficiently active surface is modifiable, and that the modified surface is remarkably stable for use with acidic and basic buffers and in neutral, polar solvent mixtures. The chromatographic utility of alumina phases was demonstrated and compared with the silica results.
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 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 Chiral Separations written by Derrick Stevenson and published by Springer. This book was released on 1988 with total page 232 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 Preparation and Characterization of Multifunctional Stationary Phases for Multimode Separations written by Asanka Wijekoon and published by . This book was released on 2010 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: High performance liquid chromatography is a powerful analytical technique employed to separate analyte mixtures. Since biomedical sample mixtures contain a very diverse range of compounds; one chromatographic mode is usually unable to separate all components of the mixture. Therefore, there is an increasing need for faster and efficient separations with a broad range of selectivity. To attain better selectivity and efficient separation, and to improve the versatility of the chromatographic column, a new way of preparation of multifunctional stationary phases, suitable for use in multiple chromatographic separation modes, is described. The preparation of multifunctional stationary phases takes advantage of Schiff base chemistry in two different synthetic routes. The first route involves reductive coupling of amino bonded silica with aldehyde containing ligands. The coupling of aldehyde bonded silica with amine containing ligands is the other reaction route. Aldehyde terminated silica is a versatile reactive platform that enables the synthesis of a wide range of stationary phases by attaching amine containing ligands that have diverse functionality. Here the preparation of aldehyde terminated silica was achieved by bonding aldehyde silane to the silica surface. Preparation of aldehyde silane is a novel approach and a successful synthetic scheme of making acetalated aromatic aldehyde silane (AAS- Aldehyde group in the silane has been protected by acetalation) and aromatic aldehyde silane (AS) is invented. The studies confirmed that the synthesized multifunctional chromatographic stationary phases were capable of operating in ion exchange mode, reversed phase mode and hydrophilic interaction liquid chromatographic mode. The studies further concluded that those surfaces have good selectivity for the separation of small polar and charge molecules. The application of the well established Schiff base reaction allowed the incorporation 2H to the bonded phases and is utilized to study the motional dynamics of the bonded ligands in the surface at different temperatures in the presence of a broad range of solvent systems by using 2H wide line NMR spectroscopy. The investigation provides information about the motional dynamic heterogeneity of the bonded ligands, which reflects the existence of surface heterogeneity of the surface.
Download or read book Chiral Separations By Liquid Chromatography And Related Technologies written by Hassan Y. Aboul-Enein and published by CRC Press. This book was released on 2003-06-03 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unique in its systematic and detailed description of the various types, structures, and properties of chiral stationary phases (CSPs) and their preparation, application, and future scope, this volume highlights an assortment of liquid chromatographic approaches, including sub- and super-critical fluid chromatography, capillary electrochromatography
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 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 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 Synthesis and Characterization of Stationary Phases for Reversed phase Liquid Chromatography written by Dale Allen Shoemaker and published by . This book was released on 1992 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Chiral Stationary Phases for HPLC written by Pik Fong Fu and published by . This book was released on 1998 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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:
