Download or read book Liquid Crystas as Stationary Phases in Gas Liquid Chromatography written by Nasreen Jber and published by LAP Lambert Academic Publishing. This book was released on 2014-03-04 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fact of intermolecular reactions or interactions between the liquid crystal and the chromatographed substances is important for the understanding of the phenomena taking place in the chromatographic column. The structure of the molecules and their polarity and polarizability affect, as well as, the solubility of the chromatographed substances in the liquid crystal plays an important influence on the separation. The properties of the liquid crystal stationary phases depend both on the structure of the main chain of the molecule and on the terminal substituents which strongly affect the polarity of the molecules. However, an equally important or even greater effect on the chromatographic properties of liquid crystals is exerted by the lateral substituents. These substituents not only affect the intermolecular reactions between the liquid crystal and the chromatographed substance but also the liquid crystal - liquid crystal interactions. The lateral substituents also affect the selectivity of the liquid crystal owing to the changes they produce in the distance between its molecules.

Download or read book Chromatographic Behavior and Evaluation of the Properties of Liquid Crystals Used as Stationary Phases in Gas Chromatography written by Joseph F. Solsky and published by . This book was released on 1978 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chromatic Behavior and Evaluation of the Properties of Liquid Crystals Used as Stationary Phases in Gas Chromatography written by Joseph Fay Solsky and published by . This book was released on 1978 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemically Bonded Liquid Crystals as Stationary Phases for High Performance Liquid Chromatography written by Shirish K. Shah and published by . This book was released on 1991 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Crystal Stationary Phases for High Performance Liquid Chromatography written by Paul Leon Sherman and published by . This book was released on 1977 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stationary Phases in Gas Chromatography written by H. Rotzsche and published by Elsevier. This book was released on 1991-08-21 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary aim of this volume is to make the chemist familiar with the numerous stationary phases and column types, with their advantages and disadvantages, to help in the selection of the most suitable phase for the type of analytes under study. The book also provides detailed information on the chemical structure, physico-chemical behaviour, experimental applicability, physical data of liquid and solid stationary phases and solid supports. Such data were previously scattered throughout the literature. To understand the processes occurring in the separation column and to offer a manual both to the beginner and to the experienced chromatographer, one chapter is devoted to the basic theoretical aspects. Further, as the effectiveness of the stationary phase can only be considered in relation to the column type, a chapter on different column types and the arrangement of the stationary phase within the column is included. The secondary aim of this book is to stimulate the development of new and improved standardized stationary phases and columns, in order to improve the reproducibility of separations, as well as the range of applications.

Download or read book Liquid Crystal Bonded Stationary Phases for High Pressure Liquid Chromatography written by Susan M. Larrabee and published by . This book was released on 2006 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects on Gas Chromatographic Peaks of Electric Fields Applied Across Cholesteric Liquid Crystal Stationary Phases written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Earlier studies have shown that a static electric field across a capillary column increased the apparent capacity ratio (measured from the peak maximum) of a liquid crystal stationary phase and produced a more nearly Gaussian-shaped peak plus a small step on the front of the peak. The present study has qualitatively confirmed those effects using cholesteryl laurate, cholesteryl 10-undecenoate, and cholesteryl benzoate and suggests that they may be found for all cholesteric liquid phases. In addition, the peak-fronting phenomenon was found to be a function of both the carrier gas and the applied column potential. Fragmentation of the solute and/or the stationary phase by carrier gas molecules in metastable excited states is proposed to explain the fronting phenomenon. Hysteresis effects have also been observed, indicating that the liquid crystals may take hours to return to their original orientations after imposition or removal of an electric field.

Download or read book Liquid Crystals in Gas liquid Chromatography written by Sharon Fay Lando and published by . This book was released on 1979 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stationary Phases in Gas Chromatography written by G. E. Baiulescu and published by Elsevier. This book was released on 2013-10-22 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stationary Phases in Gas Chromatography is a four-chapter book that begins with a description of chromatographic column, including its retention parameters; mobile and stationary phases; optimization of its process; and types of column in gas chromatography. Subsequent chapter focuses on the retention data and thermodynamic variables in the technique. The last two chapters report the different types of stationary phases in gas chromatography, as well as their selectivity.

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 Use of Novel Liquid Crystalline Polysiloxanes as Stationary Phases in Capillary Gas Chromatography written by Marian Kelly Menster and published by . This book was released on 1992 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Synthesis and Characterization of Bonded Liquid Crystal Stationary Phases for Use in High Performance Liquid Chromatography written by Mark Allen Vidensek and published by . This book was released on 1990 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Thermodynamics by Gas Chromatography written by R. Vîlcu and published by Elsevier. This book was released on 2012-12-02 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents direct and inverse gas chromatography as a powerful tool for determining a great number of thermodynamic properties and quantities for micro- and especially for macromolecular substances. In order to ensure the continuity and clarity of the presentation, the book first considers some frequently used concepts of chromatography with a mobile gas phase, i.e. the mechanism of separation, retention parameters and the theories of gas chromatography. The employment of this technique as an important method of studying solutions through the most representative statistical models is also discussed. The thermodynamics of direct gas chromatography, as applied to dissolution, adsorption and vaporization underlies the thermodynamic treatment of inverse gas chromatography. The most extensive chapter of the book is devoted to the thermodynamics of inverse gas chromatography and deals with a number of important topics: phase transitions in crystalline-amorphous polymers and liquid crystals, glass transitions, other second order transitions in polymers, the determination of diffusion coefficients, the segregation of block copolymers and other applications.This book is intended for those specialists in research and industry who are concerned with the modification and characterization of polymers, with establishing polymer applications, and with the processing of polymers. It will also be useful to students and specialists interested in the physico-chemical basis of the phenomena involved in gas chromatography in general and its inverse variant in particular.

Download or read book Applications of Gas Chromatography written by Reza Davarnejad and published by BoD – Books on Demand. This book was released on 2012-03-07 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This valuable book aims to provide a connection between various chromatography techniques and different processes. Authors applied these techniques in supercritical technology, medical, environmental, physique and chemical processes. Most of them prepared mathematical support (such as correlation) for their original results obtained from the chromatography techniques. Since chromatography techniques (such as GC, HPLC

Download or read book Synthesis Characterization and Evaluation of Liquid Crystalline Polysiloxane Stationary Phases in Capillary Gas Chromatography written by Sungmee Yoon Kim and published by . This book was released on 1994 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selection and Classification of Stationary Phases for Gas Liquid Chromatography by Principal Components and Factor Analyses written by Rungnapa Sasitorn and published by . This book was released on 1988 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: