Shinomiya Kazufusa, Zaima Kazumasa, Harada Yukina, Yasue Miho, Harikai Naoki, Tokura Koji, Ito Yoichiro
School of Pharmacy, Nihon University, 7-7-1, Narashinodai, Funabashi-shi, Chiba 274-8555, Japan.
School of Pharmacy, Nihon University, 7-7-1, Narashinodai, Funabashi-shi, Chiba 274-8555, Japan.
J Chromatogr A. 2017 Jan 20;1481:64-72. doi: 10.1016/j.chroma.2016.12.027. Epub 2016 Dec 21.
Coil satellite centrifuge (CSC) produces the complex satellite motion consisting of the triplicate rotation of the coiled column around three axes including the sun axis (the angular velocity, ω), the planet axis (ω) and the satellite axis (the central axis of the column) (ω) according to the following formula: ω=ω+ω. Improved peak resolution in the separation of 4-methylumbelliferyl sugar derivatives was achieved using the conventional multilayer coiled columns with ethyl acetate/1-butanol/water (3: 2: 5, v/v) for the lower mobile phase at the combination of the rotation speeds (ω, ω, ω)=(300, 150, 150rpm), and (1:4:5, v/v) for the upper mobile phase at (300:100:200rpm). The effect of the satellite motion on the peak resolution and the stationary phase retention was evaluated by each CSC separation with the different rotation speeds of ω and ω under the constant revolution speed at ω=300rpm. With the lower mobile phase, almost constant peak resolution and stationary phase retention were yielded regardless of the change of ω and ω, while with the upper mobile phase these two values were sensitively varied according to the different combination of ω and ω. For example, when ω=147 or 200rpm is used, no stationary phase was retained in the coiled column while ω=150rpm could retain enough volume of stationary phase for separation. On the other hand, the combined rotation speeds at (ω, ω, ω)=(300, 300, 0rpm) or (300, 0, 300rpm) produced insufficient peak resolution regardless of the choice of the mobile phase apparently due to the lack of rotation speed except at (300, 0, 300rpm) with the upper mobile phase. At lower rotation speed of ω=300rpm, better peak resolution and stationary phase retention were obtained by the satellite motion (ω) than by the planetary motion (ω), or ω>ω. The effect of the hydrophobicity of the two-phase solvent systems on the stationary phase retention was further examined using the n-hexane/ethyl acetate/1-butanol/methanol/water system at different volume ratios. In the satellite motion at (ω, ω, ω)=(300, 150, 150rpm), almost constant stationary phase retention was obtained with the lower mobile phase regardless of the hydrophobicity of the solvent system whereas the stationary phase retention varied according to the volume ratio of the two-phase solvent system for the upper mobile phase. However, stable stationary phase retention was observed with either phase used as the mobile phase. In order to analyze the acceleration acting on the coiled column, an acceleration sensor was set on the column holder by displacing the multilayer column. The combination of the rotation speeds at (300, 100, 200rpm) showed double loops in the acceleration track, whereas (300, 150, 150rpm) showed a single loop, and all other combinations showed, complex tracks. The overall results indicate that the satellite motion is seriously affected by the combination of rotation speeds and the hydrophobicity of the two-phase solvent system when the upper phase was used as the mobile phase for separation.
螺旋卫星离心机（CSC）产生复杂的卫星运动，该运动由螺旋柱围绕三个轴的三重旋转组成，这三个轴包括太阳轴（角速度，ω）、行星轴（ω）和卫星轴（柱的中心轴）（ω），其计算公式如下：ω = ω + ω。在转速组合（ω，ω，ω）=（300,150,150转/分钟）时，使用乙酸乙酯/1-丁醇/水（3:2:5，v/v）作为下层流动相、（1:4:5，v/v）作为上层流动相，在转速（300:100:200转/分钟）下，采用传统的多层螺旋柱，实现了4-甲基伞形酮糖衍生物分离中峰分辨率的提高。通过在ω = 300转/分钟的恒定转速下，对不同ω和ω转速的每个CSC分离实验，评估了卫星运动对峰分辨率和固定相保留的影响。对于下层流动相，无论ω和ω如何变化，峰分辨率和固定相保留几乎恒定；而对于上层流动相，这两个值会根据ω和ω的不同组合而敏感变化。例如，当使用ω = 147或200转/分钟时，螺旋柱中没有保留固定相，而ω = 150转/分钟时可以保留足够体积的固定相用于分离。另一方面，（ω，ω，ω）=（300,300,0转/分钟）或（300,0,300转/分钟）的转速组合，无论选择哪种流动相，显然由于除了上层流动相在（300,0,300转/分钟）时有转速外缺乏转速，导致峰分辨率不足。在较低的ω = 300转/分钟转速下，卫星运动（ω）比行星运动（ω）获得了更好的峰分辨率和固定相保留，即ω > ω。使用不同体积比的正己烷/乙酸乙酯/1-丁醇/甲醇/水体系，进一步研究了两相溶剂系统的疏水性对固定相保留的影响。在（ω，ω，ω）=（300,150,150转/分钟）的卫星运动中，对于下层流动相，无论溶剂系统的疏水性如何，固定相保留几乎恒定；而对于上层流动相，固定相保留会根据两相溶剂系统的体积比而变化。然而，无论使用哪一相作为流动相，都观察到了稳定的固定相保留。为了分析作用在螺旋柱上的加速度，通过移动多层柱，在柱架上设置了一个加速度传感器。（300,100,200转/分钟）的转速组合在加速度轨迹上显示出双环，而（300,150,150转/分钟）显示出单环，所有其他组合显示出复杂的轨迹。总体结果表明，当使用上层相作为分离的流动相时，卫星运动受到转速组合和两相溶剂系统疏水性的严重影响。
