Organic monoliths for high‐performance reversed‐phase liquid chromatography

Abstract

RPLC is the most common mode of LC. It is widely used for separations of both small and large molecules. Monolithic columns, which are currently under intensive study by many groups, have the potential of becoming attractive alternatives to particle-packed columns. They are generally easier and faster to fabricate, and they demonstrate a lower pressure drop, less nonspecific adsorption, and richer chemistry (in the case of organic polymer monoliths) for providing broad selectivity. Silica monoliths, as is also true for columns packed with silica particles, are best applied to small-molecule separations. Organic polymer monoliths, on the other hand, have shown advantages for large-molecule separations. Recently, improvements in organic monoliths have led to efficiencies for small molecules that are approaching and even surpassing 100,000 plates/m. While this performance is still far short of what is currently available using modern small particles and silica monoliths in RPLC, steady progress is being made. This review describes recent developments in the synthesis and performance of organic polymer RPLC monoliths, and identifies areas where additional work is needed to significantly improve their performance for both small- and large-molecule separations.

A novel polymeric monolith prepared with multi-acrylate crosslinker for retention-independent efficient separation of small molecules in capillary liquid chromatography

“…However, column E produced the minimum plate height of 10.75-20.04 mm for alkylbenzenes, corresponding to 50,000-93,000 N m À1 . A large amount of LMA-based polymeric monolithic columns had been prepared in the past decades, and ethylene dimethacrylate (EDMA) was commonly selected as crosslinker [3,32,[34][35][36][37][38][39]. As one kind of polymer-based monolithic columns, the resulting poly (LMA-co-EDMA) produced low column efficiencies for small molecules in the isocratic elution, on which the highest column efficiency could only reach 53,000 N m À1 for alkylbenzenes by cLC.…”

“…In recent years, monolithic columns have developed rapidly in preparation, characterization and application in separation of small molecules and macromolecules due to their excellent chromatographic properties [1,2], such as facile preparation, fast separation at high flow rate, varieties of functionality and good permeability [3,4]. Generally speaking, based on the nature chemistry of the monolithic matrix, monolithic columns can be divided into three types, including silica-based monolith, organicinorganic hybrid monolith and polymer-based monolith.…”

Biocompatible chiral monolithic stationary phase synthesized via atom transfer radical polymerization for high performance liquid chromatographic analysis

“…Monolithic stationary phases have been widely used for HPLC analysis because of their inherent advantages such as high column efficiency and low consumption of samples [1][2][3][4]. In the past decade, various monolithic chromatographic materials have been developed including the organic polymer-and silica-based monoliths [5][6][7].…”

Separation of intact proteins on γ‐ray‐induced polymethacrylate monolithic columns: A highly permeable stationary phase with high peak capacity for capillary high‐performance liquid chromatography with high‐resolution mass spectrometry

“…Besides the simplicity of their in situ preparation [29][30][31][32][33][34][35][36], another appealing aspect of monoliths is the possibility to easily create extra-long miniaturized column formats that can be used in high-resolution experiments, registering backpressure values compatible with currently available instrumentation. Porous polymeric stationary phases can be synthesized at any temperature and in almost any container using high energy radiation such as ␥-rays without the addition of initiators [37].…”