Co-eluent effect in partition chromatography. Rhamnose-xylose separation with strong and weak cation-exchangers in aqueous ethanol.
The effect of ethanol in aqueous eluent on the chromatographic separation was studied at 298 K. Two sugars, L-rhamnose and D-xylose, were separated by using strong and weak cation-exchangers as a stationary phase. The ionic form of the resins was Na+ or Ca2+. The separations were carried out with sugar feed concentrations up to 35 wt% and with both low (about 1%) and high (about 10%) feed volume to bed volume ratios. The separation of the sugars was improved by adding ethanol into the eluent. The separation was also significantly enhanced when the weak cation-exchangers with the greatest affinity for water were used instead of strong cation-exchangers as a separation medium for the sugars having different hydrophilicities. The experimental data were successfully explained with a rate-based column model, which accounted for the volume changes of the stationary phase. A thermodynamic sorption model was utilized in column calculations.
Tiihonen
Jari
J
Lappeenranta University of Technology, Laboratory of Industrial Chemistry, P.O. Box 20, FIN-53851 Lappeenranta, Finland. jari.tiihonen@lut.fi
Sainio
Tuomo
T
Kärki
Ari
A
Paatero
Erkki
E
D000327:Adsorption; D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange / Q000295:instrumentation*; D000431:Ethanol / Q000737:chemistry*; D012210:Rhamnose / Q000302:isolation & purification*; D013816:Thermodynamics; D014994:Xylose / Q000302:isolation & purification*
D002411:Cation Exchange Resins; D000431:Ethanol; D014994:Xylose; D012210:Rhamnose