Multicomponent Radial Flow Chromatography

Abstract

Radial flow chromatography (RFC) was introduced into the commercial market in the mid-1980s [1] as an alternative to the conventional axial flow chromatography (AFC) for preparative- and large-scale applications. Figure 14.1 shows a schematic of an RFC column with inward radial flow. Compared to AFC, the RFC geometry in Fig. 14.2 provides a relatively large flow area and a short flow path. It allows a higher volumetric flow rate with a lower bed pressure compared to longer AFC columns. If soft gels or affinity matrix materials are used as separation media, the low-pressure drop of RFC helps prevent bed compression [2, 3]. An experimental case study of the comparison of RFC and AFC was carried out by Saxena and Weil [4] for the separation of ascites using the QAE cellulose packing. They reported that by using a higher flow rate, the separation time for RFC was one-fourth of that needed for a longer AFC column with the same bed volume. It was claimed that by using RFC instead of AFC, separation productivity can be improved quite significantly [1]. Lay et al. tested and modeled a continuous RFC system for protein separation [5]. Recently, Yan et al. successfully used a commercially available 500-mL RFC column packed with ion-exchange resins to separate antiproliferative polysaccharides from Hypsizigus marmoreus. Numerous other experimental studies have also been reported using RFC columns. Both prepacked and unpacked RFC columns, with a size range from 50 mL to 200 L in bed volume, are commercially available. A comprehensive review was provided by Gu in 2013 [6].