Systematic search for suitable two-phase solvent systems for high-speed counter-current chromatography.

Abstract We have introduced two series of two-phase solvent systems which facilitate the systematic search for the solvent systems suitable for high-speed counter-current chromatography. The n -hexane—ethyl acetate— n -butanol—methanol—water systems provide a broad range of hydrophobicity, while the chloroform—methanol—water systems are extremely useful for separations of various natural products with moderate hydrophobicity. The practical use of these solvent series was demonstrated with several test samples which include dinitrophenyl amino acids, S-triazine herbicides, indole auxin, and non-ionic organic solvents.