Low-speed rotary countercurrent chromatography using a convoluted multilayer helical tube for industrial separation

An industrial-scale countercurrent chromatographic system was developed using a slowly rotating helical device which can be automated and left unattended during the operation. It uses a multilayer coiled column consisting of long convoluted Teflon tubing of 0.85 cm i.d., which provides sufficient retention of the stationary phase under a relatively high flow rate. The column is mounted on a seal-less continuous-flow rotary device which eliminates various complications such as leakage and clogging as often caused by the use of a conventional rotary seal. Using a multilayer coiled column with a 10-L capacity, 150 g of crude tea extract was successfully purified, yielding 40 g of epigallocatechin gallate of over 92.7% purity at a recovery rate of 82.6%. The present system can be scaled up for a kilogram-scale separation.