The spiral disks developed for separating biopolymers by type-J high-speed countercurrent chromatography (HSCCC) showed low resolution in protein samples probably due to a laminar flow effect of the viscous polymer phase system. The spiral disk has an advantage over the conventional multilayer coil separation column in that the channel geometry is easily modified in many ways. It also permits various inserts into the channel to improve its performance. We have found that introducing glass beads or fine Teflon threads into the channel produced intensive carryover of the stationary phase resulting in detrimental loss of the partition efficiency. However, inserting short segments of Teflon tubing into the channel at regular intervals produced positive results. It is assumed that such inserts served as a stream breaker to interrupt the laminar flow of the mobile phase especially for viscous polymer phase systems. A series of experiments was carried out by inserting short segments of Teflon tubing, 3 mm long and 2 mm ID, into the spiral channel of both single and four-spiral disks. The results indicated that in the single spiral disk the partition efficiency was improved by the number of inserts up to 300 which show similar separation with 500 inserts. A four spiral disk with 600 inserts produced the best separation for both dipeptide and protein samples, mainly by improved retention of the stationary phase due to its greater pitch of the sprial. Based on the above results we designed a new spiral disk composed of locules (elongated circular hole measuring 7mm long 2.7 mm wide and 2 mm deep) connected with a narrow transfer channel (1.2 mm wide. 0.5 mm long and 2 mm deep). This design has improved the partition efficiency of both peptide and protein separations. The results were further improved by inseting a glass beads so that the contents of the locule is efficiently mixed under the fractuating centrifugal force field while in the next locule containing no glass bead the contents were separated into two phases. Thus the system performes mixer-settler partitioning to improve the separation efficiency. This system was further refined by a new column design where the spiral channel is divided into multiple sections using barricade at the middle of the channel at regular intervals. When glass beads are placed every other sections, the system again performes a mix-settler solute partitioning while wide opening in both side of the barricase allows two phase freely counterflow through the channel to establish a steady state hydrodynamic equilibrium throughout the channel. This result is higher retention of the stationary phase to improve the peak resolution.
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