Preparative chromatography radial flow

Alternative Chromatographic Columns Commercial radial-flow chromatography (RFC) columns first appeared in the mid-1980s. RFC is an alternative to the conventional axial-flow chromatography for preparative- and large-scale applications. In a RFC column, the mobile phase flows in the radial direction rather than the axial direction. Computer simulation proves that RFC is somewhat equivalent to a pancakelike axial-flow column [Gu, in Flickinger and Drew (eds.). 

Radial compression uses radial pressure applied to a flexible-wall column to lessen wall effects. The mobile phase has a tendency to flow slightly faster near the wall of the column because of decreased permeability. The solute molecules that happen to be near the wall are carried along faster than the average of the solute band, and, consequently, band spreading results. Preparative scale radial compression chromatography columns have been found to possess efficiencies close to those of analytical-scale columns when an adequate radial compression level is used. Radial compression technology also helps lower the cost by substituting reusable column holders in place of expensive steel columns. 

The most common column system used in preparative chromatography is the axial flow cylindrical column and consequently this type of column will be considered first and in some detail. Radial flow columns, and simulated moving bed columns are also used very effectively in preparative chromatography, but these systems constitute very special and expensive apparatus. In addition, initial work with traditional columns will need to be carried out to evaluate and justify the necessary expense that is involved with these more sophisticated type of preparatiye separation systems. 

Another alternative chromatographic procedure for preparative separations is radialflow chromatography. The radial flow chromatography columns consist of two concentric porous cylindrical... 

The Simulated Moving Bed Preparative Chromatography System Radial Flow Chromatography... 

An alternative approach was suggested by Podgomik et al. They implemented radial flow mode and introduced monolithic columns of a well defined thickness. A similar idea was later implemented for the preparation of agarose monolithic columns, which were applied to pseudoaffinity chromatography using Cibacron Blue 3GA as a ligand and as bioreactors with the immobilized enzyme (3-galactosidase. 

LC Separation. Preparative scale liquid chromatography was performed with Waters PrepPak radially compressed silica columns. Fuel charges of 6 to 10 ml were carried through the column with n-pentane at a flow of 200 ml/minute. Refractive index, 254 nm ultraviolet, and 313 nm ultraviolet detectors monitored the LC effluent and keyed the collection of fractions. 

Circular chromatography can be carried out with forced-flow as well as capillary-flow mobile-phase migration (Botz et al., 1992). No special plate preparation is required for off-line radial OPLC or RPC, but for on-line radial OPLC, a sector must be isolated by scraping the layer and then impregnated with solvent (Nyiredy, 1992). 

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