Partition efficiencies of three different coiled columns for the coil satellite centrifuge at higher rotation speed...

The partition efficiencies of three different coiled columns, conventional multilayer coiled column, eccentric coiled column and toroidal coiled column, were evaluated by the separation of 4-methylumbelliferyl sugar derivatives using the coil satellite centrifuge (CSC) with an organic-aqueous two-phase solvent system composed of ethyl acetate/1-butanol/water. The CSC apparatus was reinforced the planet axis to maintain the stable satellite motion, which was completed by combining the rotation of three axes including the sun axis (the angular velocity, ω₁), the planet axis (ω₂) and the satellite axis (ω₃) under the relation at ω₁ = ω₂ + ω₃. In the present study, four different rotation speed combination types were used for the separation at the ratio (ω₁, ω₂, ω₃) = I. (300, 150, 150), II. (300, 100, 200), III. (300, 147, 153) and IV. (300, 200, 100 rpm) under different revolution speeds of ω₁ = 300, 400 and 500 rpm. In the conventional multilayer coiled column with the upper mobile phase, the rotation speed combination type II yielded the best peak resolution while the rotation speed combination types III and IV had extremely low stationary phase retention even at higher revolution speeds. This inconvenience was eliminated by using the eccentric and the toroidal coiled column. The rotation speed combination type II for the eccentric coiled column and the type IV for the toroidal coiled column produced the best separation in both the upper and the lower mobile phases among four different rotation speed combination types. The overall results indicated that better peak resolution was obtained by the eccentric coiled column than by the toroidal coiled column except for the separation with the upper mobile phase at the low revolution speed.