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Mass Transfer Kinetics (mass + transfer_kinetics)
Selected AbstractsRate constants of mass transfer kinetics in reversed phase liquid chromatographyAICHE JOURNAL, Issue 12 2005Lan Hong Abstract The parameters of the kinetics of mass transfer of several n -alkylbenzenes were measured by the method of moments on a series of columns prepared with different samples of the same RPLC packing material having widely different average particle diameters, from 3 to 50 ,m. These data were analyzed using the available models, and correlations. The best agreement between experimental and theoretical data was obtained under the assumption that the rate constant for the external mass transfer increases with increasing average particle size, an unexpected conclusion. It was also shown that the interpretation of the relative importance of the roles of pore diffusivity and surface diffusivity in the internal mass transfer kinetics is somewhat ambiguous and that the conclusion to be drawn from experimental results depends on the assumptions made regarding the tortuosity model and the relationship between kext and the average particle size. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source] Measurement of the parameters of the mass transfer kinetics in high performance liquid chromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 3-4 2003Kanji Miyabe Abstract Fundamental studies of the mass transfer kinetics are as essential as those of the retention equilibrium for a detailed understanding of the characteristics and the mechanisms of chromatographic separations. The acquisition of a large amount of reliable experimental data and of meaningful results is necessary for any further progress of our knowledge of kinetics. The main goal of this review is to provide information on the methods used to perform accurate measurements and on the data analysis procedures used for deriving the kinetic parameters characterizing mass transfer in HPLC. First, the general characteristics of several methods of determination of some kinetic parameters are briefly reviewed. Secondly, we give detailed explanations of the experimental conditions of the pulse on a plateau method (i.e., elution chromatography on a plateau of finite concentration or pulse response method) and of the data analysis procedures based on moment analysis. Thirdly, we explain some important requirements for the acquisition of appropriate experimental data and discuss corrections to be applied when deriving several kinetic parameters. Fourthly, we discuss the accuracy of the kinetic parameters derived from the pulse on a plateau method and from moment analysis. Finally, some results concerning the mass transfer kinetics in RPLC systems are demonstrated as examples. [source] | ||||||||||