kowalska - preparative layer chromatography (crc, 2003)

[...]... today in thin -layer chromatography (TLC), for which silica gel is by far the major stationary phase In column chromatography, however, reversed-phase liquid chromatography using chemically bonded stationary phases is the most popular method Preparative layer chromatography (PLC) was apparently first reported by F.J Ritter and G.M Meyer in 1962 [3] They used layers of 1-mm thickness Earlier preparative. .. Analtech and an automated spray-on apparatus from CAMAG Plates with 0. 5- to 2-mm layer thickness are normally used for increased loading capacity Layers can be self-made in the laboratory, or commercially precoated preparative plates are available with silica gel, alumina, cellulose, C-2 or C-18 bonded silica gel, and other sorbents Resolution is lower than on thinner analytical layers having a smaller average... students Dr Kowalska is the author of more than 200 scientific papers, more than 300 scientific conference papers, and a vast number of the book chapters and encyclopedia entries in the field of chromatography It is perhaps noteworthy that she has authored (and then updated) the chapter on “Theory and Mechanism of Thin -Layer Chromatography for all three editions of the Handbook of Thin -Layer Chromatography, ... adsorption isotherms, whereas others are in the nonlinear (i.e., mass-overload) range However, mostly because of the intuitive, trial-and-error approach of thin -layer chromatographers, long ago the technique split into two subtechniques, one benefiting from the linear range of the adsorption isotherm and the other utilizing the 6 Preparative Layer Chromatography advantages of the nonlinear range Much less attention... PLC High-quality precoated preparative plates are available from a number of commercial sources Alternatively, less expensive or specialty preparative plates can be “homemade” in the laboratory, and loose sorbents and coating devices can be purchased for this purpose More-or-less-automated devices can also be purchased for band application of higher quantities of sample solutions to preparative layers... consecutive adsorbed layers [7,8] Adsorption Planar Chromatography in the Nonlinear Range 15 Assuming that the equilibria between the adjacent layers are depicted by the same equilibrium constant Kp and that K is the equilibrium constant between the first layer and the active sites, the two -layer isotherm model can be expressed as: q = qs ( KC 1 + 2 K pC ) (2.7a) 1 + KC + KCK pC and the three -layer model by... nonlinear adsorption TLC was conceived, and to a large extent remained, an “unofficial” and almost “underground” separation technique Among chromatography practitioners, it is known as PLC (or PTLC [preparative thin -layer chromatography] or PPC [preparative planar chromatography] ), and it is generally accepted that this otherwise very useful separation tool does not serve an analytical purpose, at least... Teresa Kowalska is currently a professor in the Department of the Physicochemical Basis of Chromatography at the University of Silesia (Katowice, Poland) Her scientific interests include the physicochemical foundations of liquid chromatography and gas chromatography, with special attention focused on modeling of planar chromatography both in its analytical and preparative mode Over the past 37 yr Dr Kowalska. .. phase to the layer in PLC is with the aid of capillary forces in the ascending direction Forced-flow development can also be used for analytical TLC and PLC The most popular forced-flow modes are overpressured layer chromatography (OPLC; sometimes termed optimum performance laminar chromatography) , in which the mobile phase flow is due to mechanical force (pressure), and rotation planar chromatography. .. precoated layers for reversed-phase chromatography (RP-18 or C-18) Properties of the bulk sorbents and precoated layers, a survey of commercial products, and examples of substance classes that can be separated are given Chapter 4 discusses the selection and optimization of mobile phases for successful separations in PLC Chapter 5 details procedures for sample application and development of layers, and . States of America on acid-free paper 10987654321 International Standard Book Number-10: 0-8 49 3-4 039-X (Hardcover) International Standard Book Number-13: 97 8-0 -8 49 3-4 03 9-0 (Hardcover) Library. Discovery, Paul C.H. Li 95. Preparative Layer Chromatography, edited by Teresa Kowalska and Joseph Sherma 4039_half-series-title.qxd 12/14/05 1:12 PM Page E edited by Teresa Kowalska University of. Regnier 88. Scale-Up and Optimization in Preparative Chromatography: Principles and Bio-pharmaceutical Applications, edited by Anurag S. Rathore and Ajoy Velayudhan 89. Handbook of Thin -Layer Chromatography: