Improved spiral disk assembly for high-speed counter-current chromatography.

The spiral disk for type-J high-speed counter-current chromatography (HSCCC) has been improved by placing short segments of PTFE (tetrafluoroethylene) tubing into the channel at regular intervals. The best results were obtained with a four-channel spiral column using 600 spacers, which significantly improved stationary phase retention and partition efficiency in both n-butanol-acetic acid-water (4:1:5) and poly(ethylene glycol) 1000-dibasic phosphate polymer phase systems. Based on these findings, a "bead-chain spiral disk" was designed and its performance tested with a type-J HSCCC centrifuge. This new column design substantially improved the separation of both dipeptide and protein samples in terms of stationary phase retention and partition efficiency.