Characterization of monolithic columns for HPLC

Abstract

Monolithic stationary phases and columns have rapidly become highly popular separation media for liquid chromatography, in spite of their recent discovery. However, their most important features have not yet been completely clarified. A complete understanding of their performance and of their intrinsic characteristics will require the systematic acquisition of many series of reliable experimental data and their consistent analysis from different points of view. Progress in their design and production requires now that the chromatographic behavior of monolithic columns be studied in close connection with their physico-chemical and structural properties. The main goal of this review is to summarize fundamental information on some physico-chemical and chromatographic characteristics of monolithic stationary phases and columns for RPLC. The material reviewed deals only with silica-based monolithic columns. First, structural information on the porosities and the size of the pores in monolithic columns is reported. Second, results of chromatographic studies that deal with the characterization of monolithic columns are summarized. Third, results of detailed studies made on the adsorption equilibrium and the surface heterogeneity of monolithic stationary phases are presented. Finally, results on the mass transfer kinetics in monolithic columns derived from the applications of the classical random-walk model and of the moment theory to a new model of the monolith are discussed.

Rapid and Simultaneous Determination of Tetrafluoroborate, Thiocyanate and Hexafluorophosphate by High-Performance Liquid Chromatography Using a Monolithic Column and Direct Conductivity Detection

“…These allow higher flow-rates of eluent due to lower backpressures without much loss of performance. 29,30 In recent years, the preparation and application of monolithic columns have been developed rapidly in capillary electrochromatography (CEC), HPLC and IC. [30][31][32][33][34][35] The main forms of monoliths are organic polymer monoliths and silica-based monoliths.…”

New Trends in Fast Liquid Chromatography

“…[5] The separation performance is based on macropore and mesopore size. With this bimodal structure it is possible to work at high flow rates without excessive backpressure (high permeability) and loss in efficiency.…”

Moment Equations for Chromatography Using Superficially Porous Spherical Particles

“…[23][24][25][26][27][28][29][30][31][32][34][35][36][37][38][39][40][41] Then, a set of moment equations were used for analyzing experimental data of chromatographic behavior of shell-type particles, which were previously published by other researchers, 39 in order to demonstrate the effectiveness of the new moment equations.…”