Novel Monolithic Stationary Phase with Surface-Grafted Triphenyl Selector for Reversed-Phase Capillary Electrochromatography

Preparation of Monolithic Silica and Polymer Capillary Columns with Ultrahigh Column Efficiencies and Comparisons between van Deemter Plots of Alkylbenzenes on These Two Kinds of Columns

Monolithic silica and polymer capillary columns with ultrahigh column efficiencies were prepared. Permeability and electrochromatography performances of these two kinds of columns were compared. Monolithic silica columns bear higher permeability than polymer counterparts by two orders of magnitude. Furthermore, the van Deemter plots of alkylbenzenes on these two kinds of columns demonstrate that monolithic silica columns produce much lower plate heights of alkylbenzes than polymer columns do. Within the range of electroosmotic flow (EOF) velocity investigated, no uptrend of plate height with the increase of EOF was observed suggesting the great capacity of fast separation and high efficiency. The plate height of thiourea on monolithic silica columns is as low as 2.67 μm, representing its corresponding column efficiency is over 430,000 plates/m. As far as we know, it is the highest ever column efficiency reported in the literature. Moreover, the separation of butylbenzene isomers was obtained on the monolithic silica column.

Various Strategies in Post-Polymerization Functionalization of Organic Polymer-Based Monoliths Used in Liquid Phase Separation Techniques

This review article is aimed at summarizing the various strategies that have been developed so far for post-polymerization functionalization (PPF) of organic polymer-based monoliths used in liquid phase separation techniques, namely HPLC at all scales and capillary electrochromatography (CEC). The reader will find the organic reactions performed on monolithic columns for grafting the chromatographic ligands needed for solving the separation problems on hand. This process involves therefore the fabrication of template monoliths that carry reactive functional groups to which chromatographic ligands can be covalently attached in a post-polymerization kind of approach. That is, the template monolith that has been optimized in terms of pore structure and other morphology can be readily modified and tailor made on column to fit a particular separation. The review article will not only cover the various strategies developed so far but also describe their separation applications. To the best of our knowledge, this review article will be the first of its kind.