Twenty years of continuous bed (monolithic) techniques : unsurpassed flexibility and success

The pioneering work on synthesis and application of non-particulate stationary phases for liquid chromatography was published in 20 years ago [1]. Numerous publications, growing interest and a number of non-particulate phase products released by several companies, such as CIM Disk (BIA Separations, Ljubljana, Slovenia), CB Silica plate (Conchrom, Bremen, Germany), SepraSorb (Sepragen, San Leandro, California), CIM Tube, CIM Disk (BIA Separations, Ljubljana, Slovenia), UNO (BioRad, Richmond, California), Swift (ISCO, Lincoln, Nebraska), Chromolith, Chromolith CapRod (Merck, Darmstadt, Germany), Monoliths (LC Packings, Amsterdam, The Netherlands), Onyx (Phenomenex, Torrence, California) illustrate an importance of this technique for chromatographic analysis and its maturity. The monolithic (continuous bed) stationary phases primarily synthesized as chromatographic media for biocompound separations are regarded as the fourth generation of biochromatographic stationary phases. Monoliths (continuous beds) are widely used in the HPLC and capillary format separations. They are also used in the chip format separations. Compatibility of the technique with the capillary format separations gained particular interest of the researchers and companies developing chromatographic columns for micro and nanoseparations (column I.D. >150 µm and I.D.