New moment equations for chromatography using various stationary phases of different structural characteristics.
New moment equations were systematically developed for chromatography using various types of separation media having different structural characteristics, i.e., shape (spherical particle, cylindrical fiber, flat plate) and porous structure (full-porous, partially porous (pellicular), nonporous). First, a set of basic equations of the general rate model of chromatography representing the mass balance and the mass-transfer kinetics were analytically solved in the Laplace domain. Then, the moment equations in the real-time domain of the first absolute moment and the second central moment were derived from the analytical solution in the Laplace domain. The new moment equations were used for predicting the chromatographic behaviors of benzene in the hypothetical RPLC systems using the full-porous, partially porous (pellicular), and nonporous spherical particles as packing materials. The influence of the difference in their structure on the total performance of the three types of spherical particles as the separation media for the fast HPLC with a high efficiency was quantitatively evaluated from the viewpoints of the column efficiency, column back pressure, and sample retention strength. The framework of the new moment equations can provide not only the qualitative but also the quantitative information about the intrinsic characteristics of the chromatographic behaviors of various separation media having the different shapes and structures. This study is devoted to demonstrating the important advantage of the moment analysis strategy over the conventional plate theory and rate models of chromatography.
Miyabe
Kanji
K
Graduate School of Science and Engineering for Research, University of Toyama, 3190, Gofuku, Toyama 930-8555, Japan. miyabe@eng.u-toyama.ac.jp