NOVEL DESIGN FOR CENTRIFUGAL COUNTER-CURRENT CHROMATOGRAPHY: III. SAW TOOTH COLUMN

Abstract

The toroidal coil using an equilateral triangular core and zigzag pattern column have improved both retention of the stationary phase and peak resolution of the conventional toroidal coil in centrifugal counter-current chromatography. To further improve the retention of stationary phase and peak resolution, a novel saw tooth column was designed and the performance of the system was evaluated at various flow rates. The results indicated that both retention of the stationary phase and peak resolution were improved as the flow rate was decreased and at a flow rate of 0.005 mL/min the resolution is remarkably increased. Modification of the tubing called flat-twisted tubing further improved the peak resolution without increasing the column pressure. With decreased column length at a capacity of about 0.2 mL, resolution of the saw tooth column was 1.02.

Keywords:

• counter-current chromatography
• dipeptide
• DNP-amino acid
• resolution
• retention of the stationary phase
• saw tooth column

Notes

Note: Flow rate: 0.05 mL/min; rotational speed: 1000 rpm.

^a The layer is the vertical layers at the same radius.

^b Rs-a = Rs(V₁/V₂)^1/2, where Rs-a is the adjusted peak resolution and V indicates the column volume being specified by the subscript 1 for the plain column and 2 for a column of compared column.

^c N-a = N L₁/L₂ = N (17.5/13.5) = 1.3 N, where N-a is the adjusted theory plate number and L indicates the column length or layers being specified by the subscript 1 for the plain column or layers and 2 for a column of compared length or layers.