The design of a new concept chromatography column

Abstract

Active Flow Management is a new separation technique whereby the flow of mobile phase and the injection of sample are introduced to the column in a manner that allows migration according to the principles of the infinite diameter column. A segmented flow outlet fitting allows for the separation of solvent or solute that elutes along the central radial section of the column from that of the sample or solvent that elutes along the wall region of the column. Separation efficiency on the analytical scale is increased by 25% with an increase in sensitivity by as much as 52% compared to conventional separations.

Forced-Flow Development in Overpressured Layer Chromatography

“…A similar approach was applied for the reduction (elimination) of the so-called wall effects in HPLC columns and the process was termed active flow management covering the combination of conventional and curtain flow injection with the detection of the central part of the parallel segmented outlet flow [21,22].…”

Exogenous factors contributing to column bed heterogeneity

“…Most important is, the radial bed heterogeneity because the variation in the fluid flow velocity across the column radial cross section causes severe distortion of the solute band, resulting in 'bowl' like elution profiles [15]. The development of the Active Flow Technology (AFT) column end fitting [16][17][18][19] has shown conclusively that band distortions that result from the heterogeneity in packing density can to a very significant degree be moderated since the flow from these AFT columns is collected from the more uniform radial central region of the column bed, hence effectively eliminating wall effects [13] and other aspects that contribute to radial flow heterogeneity. These fittings offer advantages at HPLC scale columns or prep scale columns, including columns utilised in low pressure environments such as FPLC.…”

Influence of Ring Frit Structure on Column Efficiency

“…It incorporates two types of new column designs: (1) parallel segmented flow (PSF) columns [15] and (2) curtain flow (CF) columns [16], which also incorporate the PSF design. This technology used a segmented column fitting to separate the flow in the central part of the column from that of the wall region allowing isolating the flattest part of the warped analyte bands.…”