title: Affinity countercurrent chromatography using a ligand in the stationary phase.
abstract: In countercurrent chromatography (CCC), an addition of a ligand to the liquid stationary phase remarkably improved both retention time and peak resolution of the analytes: various amino acid derivatives were separated by N-dodecanoyl-L-proline-3,5-dimethylanilide, while polar catecholamines and dipeptides were separated by bis-(2-ethylhexyl)phosphoric acid. By selecting an appropriate ligand and dissolving it in the liquid stationary phase, the present CCC technique can perform a variety of separations comparable to chiral chromatography, ion chromatography, and affinity chromatography. Leakage of the ligand from the column can be entirely eliminated by introducing a small volume of a ligand-free stationary phase at the end of the column as an absorbent. The method further facilitates application of pH-zone-refining CCC and can increase the sample loading capacity over 10 times for a given column.
authors.affiliation: Laboratory of Biophysical Chemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1676, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification*; D002395:Catecholamines / Q000302:isolation & purification*; D002846:Chromatography, Affinity / Q000379:methods*; D003377:Countercurrent Distribution; D004151:Dipeptides / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D002395:Catecholamines; D004151:Dipeptides