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A capillary zone electrophoresis method was set up for the separation and determination of glycyrrhizin in Chinese medicinal preparations. Concentrations of Na(2)B(4)O(7) were optimized, which showed that glycyrrhizin in the sample could be separated from interference in the running buffer of 30 mmol/L Na(2)B(4)O(7). Using declofenac as internal standard, the simple method was linear in the range 25-300 microg/mL of glycyrrhizin, and good reproducibility was obtained. The extracts of Radix glycyrrhizae and its preparations could be injected directly for analysis without any pretreatment.

Tetrahydropalmatine in Rhizoma corydalis and its preparations were separated and determined with no pretreatment in the buffer solution of 50 mmol/L of sodium acetate in methanol containing 2 mol/L acetic acid.

Ferulic acid in extracts of raw herbs was separated by capillary zone electrophoresis in the buffer solution of 10 mmol/L Na(2)B(4)O(7). The simple and rapid method was linear, ranging from 5 to 100 microg/mL, and had a good reproducibility with the RSD below 2%. The contents of ferulic acid in Angelica sinensis and Chuanxiong could be easily determined within 15 min with no pretreatment and no interference.

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.

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.