Partition efficiencies of an eccentric coiled separation column for centrifugal partition chromatography

The partition efficiency of an eccentric coiled separation column, newly fabricated in our laboratory, was studied using centrifugal partition chromatography (CPC) with four different two-phase solvent systems including n-hexane-acetonitrile; tert-butyl methyl ether-aqueous 0.1% trifluoroacetic acid (I : 1); 1-butanol-water (I : 1); and 12.5% (w/w) polyethylene glycol 1000-12.5% (w/w) dibasic potassium phosphate. Each separation was performed by eluting either the upper phase in the ascending mode or the lower phase in the descending mode, each in clockwise and counterclockwise (CCW) column rotation. Better partition efficiencies were attained by the CCW rotation in both mobile phases in all the two-phase solvent systems examined. The overall results demonstrated that the coiled separation column yielded substantially higher partition efficiencies than the commercial disk column. The eccentric coiled separation column is useful for the separation by CPC.