Ground Organic Monolith Particles Having a Large Volume of Macropores as Chromatographic Separation Media

Abstract

E-mail: wjcheong@inha.ac.krReceived January 27, 2014, Accepted March 13, 2014A reaction mixture was developed for formation of soft organic monolith that was easily smashed, rinsed,refluxed, filtered, and dried to give monolith particles having high pore volume of macropores. This phase wasalmost without mesopores. The reaction mixture was composed of methacrylic acid, ethylene glycoldimethacrylate, polyethylene glycol (porogen), and an initiator in a mixed solvent of toluene and isooctane. Theselection of porogen and its amount was carefully carried out to obtain the optimized separation efficiency ofthe resultant phase. The median macropore size was 1.6 µm, and the total pore volume was 3.0-3.4 mL/g. Themedian particle size (volume based) was 15 µm, and the range of particle size distribution was very broad.Nevertheless the column (1 × 300 mm) packed with this phase showed good separation efficiency (N~10,000-16,000) comparable to that of a commercial column packed with 5 µm C18 silica particles.Key Words : Organic monolith particles, Packed column, Polyethylene glycol, Macropores, High pore volumeIntroductionA monolith is one body 3-dimensional organic or inor-ganic polymer network where macroporous pores (throughflow channels, over 1 μm) and mesoporous pores (less than1 μm) are included. A well-made monolith in a metal orsilica capillary column can be commonly used as separationmedia in liquid chromatography, capillary electrochromato-graphy (CEC), and solid phase extraction (SPE). There havebeen many review articles on organic