title: Studies on the performance of different coiled column configurations for compact type-I countercurrent chromatography.
abstract: Three types of novel coiled column configurations, i.e. a triangular coiled column and elliptical coiled columns I and II, were designed for type-I countercurrent chromatography and their performances were evaluated with two solvent systems each with suitable test samples. Three dinitrophenyl (DNP) amino acids (DNP-DL-glu, DNP-β-ala and DNP-L-ala) were separated with a moderately hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1 M hydrochloric acid (1:1:1:1, v/v), while two dipeptides (tryptophyl-tyrosine and valyl-tyrosine) were separated with a polar solvent system composed of 1-butanol-acetic acid-water (4.75:0.25:5, v/v). The overall results indicated that the performance of compact type-I countercurrent chromatography was improved by elliptical coiled column I which was mounted with its maximum coil diameter perpendicular to the surface of the column holder. Hydrodynamic effects involved in these separations were discussed.
authors.affiliation: Bioseparation Technology Laboratory, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1762, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Dongyu
authors.initials: D
authors.lastname: Gu
authors.forename: Haji Akber
authors.initials: HA
authors.lastname: Aisa
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D004151:Dipeptides / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D004151:Dipeptides