Recycling foam countercurrent chromatography

A new sample injection method for foam countercurrent chromatography (CCC), named the "recycle injection system", has been developed. In this system, the effluent from the liquid outlet is directly returned into the column th rough the sample feed line so that the sample solution is continuously recy cled for repetitive foam fractionation, The utility of this system was demo nstrated in the separations of microcystin ex-tract and bacitracin complex from large volumes of sample solution. Microcystins were separated and enri ched in decreasing order of hydrophobicity, Bacitracin A, a hydrophobic maj or component, in the bacitracin complex was highly enriched in the foam fra ction and almost completely isolated from other components. This recycling foam CCC method may be effectively applied for separation and enrichment of various foam-active components from crude natural products.