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A micellar electrokinetic capillary chromatographic method was set up for the quality control of rhubarb and its preparations. Anthraquinone derivatives were separated successfully within 10 min in the buffer solution of 50 mmol/L H3BO3-NaOH (pH 11) containing 25 mmol/L sodium deoxycholate. The established method, with a recovery of extraction of over 90%, has good linear relationship and reproducibility. The contents of anthraquinone derivatives in rhubarb and a tablet of Niu-huang-jie-du differed significantly, showing that the quality control of rhubarb and its preparations is necessary. Copyright © 1998 John Wiley & Sons, Ltd.

A micellar electrokinetic capillary chromatographic method was set up for the separation of five anthraquinone derivatives in rhubarb. Optimization of pH and sodium deoxycholate(SDC) concentrations was studied, which showed that 50 mM H3BO3-NaOH(pH 11) containing 25 mM SDC could separate the five ingredients completely within 10 min with good reproducibility of elution time. © 1998 John Wiley & Sons, Ltd.

Aiming to attenuate the fluctuation caused by static friction torque of the SPG, the dissipation energy produced by the slip distance from the static friction to the lubrication is analyzed based on the Hertz Contact Theory. Considering the time amplification effect of the structure resonance, the amplitude and the width of the single pulse are calculated to impulse the first order rotation mode of the SPG. Then, a formula of the compensation pulse is deduced, and At last, the disturbance caused by the slipping energy is well compensated by the vibration energy of SPG. Using this method, the torque fluctuation of passing zero speed degrade and the residual stress from the SPG to the spacecraft is reduced. At the same time, this conclusion provides a theory basis for the optimization of the controlling system.