Monolithic columns advantages

Monolithic columns have been available for many years and continue to be a part of the high-throughput discussion. Chapter 4 provides a brief description of the structure of monolithic columns as well as a discussion of some of their advantages and disadvantages. In this section we will briefly discuss some of the applications developed as related to fast analyses and what chemists are hoping to achieve by using monoliths. 

However, silica monoliths and organic polymers both exhibit very advantageous chromatographic characteristics enhanced mass transfer characteristics, high reproducibility, and versatile surface chemistry, which make monolithic column attractive for a variety of forward-looking applications. 

The major advantage of CEC compared to classical HPLC is that much higher column efficiencies can be achieved using identical separation media. For columns packed with beads, the column efficiency of both of these methods is particle size dependent, and increases as the size of the packing decreases [1], Since the monolithic columns are molded rather than packed, issues of particles size become irrelevant, and instead, the size of the pores within the monolithic material is the variable most... 

During the past 10 years, in addition to silica-based monoliths [12], a broad range of organic polymeric monoliths has been studied. Their most advantageous attribute is their chemical stability over a wide pH range. The most common organic monoliths were the results of methacrylate [13] and styrene [14] monomers. Some examples that confirm the utility of monolithic columns in IPC are described below. 

The increased popularity of CEC is the result of its advantages that include the vastly increased column efficiency compared to the conventional pressure-driven chromatography. CEC was also adopted for the separations of enantiomers, employing two major modes similar to those used in CE. In the simplest mode, a chiral selector is added to the mobile phase. At present, a less erroneous and more elegant technique uses an open tubular conventional packing or preferably a monolithic column containing an immobilized chiral selector that discriminates the enantiomers. 

The main advantages of monolithic columns are the superior separation performance and low flow resistance. In addition due to their continuous nature, frits are not required to retain the stationary phase. The production process of monolithic columns is more flexible than that of packed columns e.g., photo-polymerization can be applied to prepare monolithic structures or add selectivity locally. Both polymer- and silica-based monolithic capillary columns have been used for highly efficient separations in LC-mass spectrometry (MS) applications for proteomic research [24,25]. 

The application of monolithic columns for efficient RP-HPLC separation of proteins is rapidly developing. The advantage of monolithic columns for protein separations is the high mass transfer efficiency due to convective flow in the macroporous structure. As a result, very fast separations can be achieved. 

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