Biseps, Inc.  Advanced Columns and Methods for Preparative Bio-Chromatography


Home Stagnant space Resolution Graphs and Data Consistency Quality

 

Separation on a packed SPC is characterized by :

  • shortened equilibration and process time,

  • reduced buffer consumption and

  • increased purity/yield. 

Indeed:

SPC has inlet and outlet located at the opposite edges of the column. This patented  feature compensates for the "smiling effect" - especially in large diameter ("pancake") columns. 

In contrast, the conventional header (distributor) reduced the plate number by up to 50% (data for 44-cm ID, 10-cm bed column, see page 139 in J. Moscariello et al., J. Chromatogr. A 908 (2001) 131-141.

SPC
Equal distances (and equal pressure drop) along the pathways A=B=C result in a uniform flow.  Diagonal position of the inlet and outlet compensates for the “smiling” effect rather than attempts to reduce it.  Result: SPC design affords wide distributors - so that even large "pancake"  columns operate at high flow rate without sacrifice of peak width or peak tailing, and at low back-pressure.		 Conventional design.
Peripheral (A,C) pathway is longer than the central one (B). The larger the distributor (gap) the worse the zone broadening.  A narrow* distributor gap reduces the “smiling” - but chokes the lateral flow and results in zone tailing* along the periphery.  Tailing and/or back-pressure aggravates in large "pancake"  columns.

* See data on the Data&Graph page, Fig.3 

 

In order to directly compare "diagonal"  and  "central" elution modes, a special dual-mode column was constructed.  This rectangular column (H:W:L=2:0.6:12-cm) models a cross-section of an ordinary circular column. When a dye is injected, the column allows to observe and compare flow distribution patterns.  Plate number (N) was calculated from the elution peaks. (Click here for more data on these experiments).