Progress in High Performance Liquid Chromatography (III)

——The development of integrated chromatography columns in recent years(Fu Ruonang)

At the beginning of the new century, due to the needs of life sciences, new drug development, and environmental sciences, liquid chromatography, microcolumn liquid chromatography, and capillary electrochromatography have received widespread attention. However, for the past 20 years, the column efficiency of commercial HPLC chromatography columns has hovered between 10000 and 30000 pl/elum，to solve this issue, CE, CEC, and ultra-high pressure liquid chromatography (UHPLC) have been developed. But these methods all have some issues.Therefore, monolithic chromatography columns have attracted great interest, as fillers based on organic polymers have good compatibility with biomolecules and become excellent substitutes for silica gel. Everyone can make their own integrated chromatographic columns because the preparation of these columns avoids the usual filling of fillers and the production of stoppers. The micro-HPLC column of the overall chromatographic column will become GC Strong competitors of CEC and UHPLC.

Liquid chromatography, microcolumn liquid chromatography, and capillary electrochromatography all require the preparation of chromatography columns. The preparation of the chromatographic column follows L · A There are three types of Colon's statement: 1. Filling chromatography columns with particle fillers; 2.The use of in-situ polymerization in a column to produce a columnar,  rod-shaped packing material is called bulk chromatography(Monolithiccolumn); 3.Fill the particle filler with polymer and solidify it in the chromatographic column, that is, combine the first two together. The first method includes the preparation of stationary phase fillers, the production of chromatographic column stoppers, and the filling of chromatographic column fillers, especially the production of micro column stoppers, which is a combination of technology and art and has certain difficulties, to avoid the difficulty of preparing chromatographic columns, a simple and flexible method for preparing columns for liquid chromatography and capillary electrochromatography is proposed，which is second and third methods, collectively referred to as integral chromatography columns 3.4,5-6,7,8. This is a continuous bed integrated chromatographic column that uses organic or inorganic polymerization for in-situ polymerization within the chromatographic column，this chromatographic column preparation method is simple, fill the prepared mixture of monomers, additives, pore forming agents, and initiators into an empty chromatographic column, and after a period of polymerization reaction, it becomes a complete chromatographic column. Due to the use of polymerization methods, various possible functional groups can be introduced into the stationary phase, resulting in a highly variable flexibility. The chromatographic column has both flow-through pores (close to 1 μ m) for the mobile phase and mesopores (several tens of nanometers) for solute mass transfer, making it possible to quickly separate biomolecules. Additionally, the stability of the chromatographic column is excellent. The use of integral chromatography columns in capillary electrochromatography can avoid the difficulty of making stoppers and eliminate the problem of bubbles generated by stoppers. At present, the main types of monolithic columns are organic polymer monolithic columns, inorganic oxide monolithic columns and organic plus inorganic sol gel monolithic columns. The overall chromatographic column already has products available, such as Merck KGaA SilicaRod integrated chromatography column and BioRad (Munich, Germany) UNOQ1 integrated chromatography column 9.10.