Two-dimensional counter-current chromatography: 1st traditional counter-current chromatography, 2nd acid-base elution counter-current chromatography.
An on-line column-switching counter-current chromatography (CCC) with solid-phase trapping interphase is presented in this paper. The large volume injection is avoided using solid-phase trapping interphase. Thereby, totally different chemical composition biphasic solvent system can be utilized to enhance system orthogonality. In the present work, a 140 mL-capacity CCC instrument was used in the first dimension, and a parallel three-coil CCC centrifuge (40 mL each coil) was used in the second dimensional separation allowing three injections at the same time. With biphasic solvent system composed of n-hexane: ethyl acetate: methanol: water (1:1:1:1, v/v), five well-separated fractions were obtained in the first dimension. Two fractions were online concentrated and further separated in the second dimension with solvent system composed of methyl tert-butyl ether: acetonitrile: water (2:2:3, v/v), where trifluoroacetic acid (10 mM) was added to the upper organic phase as a retainer and triethylamine (10mM) to the aqueous mobile phase as an eluter. Four hydroxyanthraquinones were successfully separated and purified from Chinese medicinal plant Rheum officinale in only one step.
Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
Ruilin
R
Hu
Xiaojing
X
Dai
Xia
X
Xu
Cuirong
C
Sun
Yuanjiang
Y
Pan
D000880:Anthraquinones / Q000737:chemistry / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification*; D015394:Molecular Structure; D012250:Rheum / Q000737:chemistry*
D000880:Anthraquinones; D004365:Drugs, Chinese Herbal