Simultaneous separation and determination of five isoflavones in Paeonia Lac⁃ tiflora Radix and its preparations by micellar capillary electrophoresis

A new method of micellar capillary electrophoresis was developed for the simultaneous separation and detection of puerarin，daidzin，3'-methoxypuerarin，3'-hydroxypuerarin，and 4'-methoxypuerarin. The buffer solution consisted of 40 mmol/L Na2 B4 O7 and 4 mmol/L NaOH（pH 9.62），with 5%（V/V）methanol and 14 mmol/L sodium dodecyl sulfate （SDS）as additives. The separation voltage was 22 kV，the detection wavelength was 250 nm，and the injection time was 5 s. Under the optimized conditions，five isoflavones could be separated and detected within 14 min，and the linear relationship between the peak area of each target component and its concentration was good. The method was applied to the quantitative analysis of five isoflavones in Pueraria lobata and its preparations. The spiked recoveries ranged from 95.6% to 104.8%，and the relative standard deviation was not more than 4.0%. © 2023, Youke Publishing Co.,Ltd. All rights reserved.