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

Abstract

A 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 was almost without mesopores. The reaction mixture was composed of methacrylic acid, ethylene glycol dimethacrylate, polyethylene glycol (porogen), and an initiator in a mixed solvent of toluene and isooctane. The selection of porogen and its amount was carefully carried out to obtain the optimized separation efficiency of the resultant phase. The median macropore size was 1.6 µm, and the total pore volume was 3.0-3.4 mL/g. The median 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.

C18‐bound porous silica monolith particles as a low‐cost high‐performance liquid chromatography stationary phase with an excellent chromatographic performance

“…Studies of monolith particles prepared by crushing bulk monoliths have been rare although molecularly imprinted polymer particles were prepared in such a way in the early years . Ground organic monolith particles were employed as new chromatographic separation media very recently .…”

Development of Ground Organic Monolith Particles as Packing Material in High Performance Liquid Chromatography

“…The observed reproducibility based on the three different columns was in the range of 1.7–5.8% depending upon the analyte. The overall average plate count was 18 300 plates/column (61 000 plates/m, 16.4 μm HETP), which is significantly better than that of previous study (14 000 plates/column) . The major factor of such improvement is reduction of particle size.…”

“…On the other hand, a fewer number of studies have been carried out on ground organic monolith particles, and the separation efficiency of columns packed with the organic monolith particles was much inferior to that of above phases based on silica monolith particles . The column separation efficiency of average 14 000 plates/column was achieved with the particles of ca 15 μm size …”

“…A new generation of stationary phases have been developed in our laboratory in order to resolve the disadvantages of packed columns (high column back pressure) and monolithic columns (low amount of stationary phase) simultaneously: ground monolith particles . The main idea here is to grind the monolith into particles and pack the column with stationary phases based on ground monolith particles.…”

Development of a New Solid Phase Extraction Cartridge Filled with Organic Monolith Particles for Extraction of di‐Alkyl Phthalates

“…In our laboratory, a chromatographic study was carried out with a column packed with ground organic monolith particles derived from a monolith prepared by polymerization of methacrylic acid (MAA, monomer) and ethylene glycol dimethacrylate (crosslinker). It resulted in column separation efficiency of 14,100 plates (average) for separation of a sample composed of N ‐methylaniline, phenol, acetophenone, benzene, and toluene …”