| A micellar electrokinetic capillary chromatographic(MEKC) method was established for the simultaneous determination of liquiritin,rutin,hyperin,quercitrin,chlorogenic acid and rhein in Lianhuaqingwen Capsule.Effects of experimental conditions,such as pH value,concentration of sodium dodecyl sulfate(SDS),type of organic modifier,concentration of background electrolyte and applied voltage, on separation efficiency of six targeted compounds were optimized.A baseline separation of six components was achieved in 30 min when the samples were separated on an uncoated fused silica capillary column(75 μm×60 cm,effective length 50 cm),using 50 mmol/L SDS-15 mmol/L Na2HPO4-15 mmol/L H3BO3 (containing 25% 2 propanol,pH= 80)as running buffer,with applied voltage of 30 kV.The analytes were detected by UV detection at 254 nm.Under the optimum conditions,the calibration curves were linear in the range of 4.5-120 mg/L for liquiritin,3.0-100 mg/L for rutin,1.5-50 mg/L for hyperin,1.5-100 mg/L for quercitrin,4.5-600 mg/L for chlorogenic acid and 0.90-160 mg/L for rhein with detection limits of 1.5,1.0,0.50,0.50,1.5,0.30 mg/L,respectively.The average recoveries of the six components were between 90% and 108% with all relative standard deviations not more than 4.2%.The developed method was simple,rapid and accurate,and was suitable for the routine analysis of the six effective components in Lianhuaqingwen Capsule. |