Comparison of capillary electrophoresis and high performance liquid chromatography for determination of flavonoids in Achillea millefolium.

Flavonoids represent an important bioactive component in Achillea millefolium. The comparison of the most commonly used analytical methods for the identification and quantification of flavonoids, capillary electrophoresis (CE) and high performance liquid chromatography (HPLC), is presented. The methods were optimized and validated. Using a 20 mM borate buffer with 30% (v/v) of methanol (pH 9.3) in the CE analysis and a gradient elution with water-acetonitrile mobile phase in the HPLC analysis, sufficient separation of the analytes was achieved. A relatively high injection volume in the CE analysis (30 mbar x 30s) enabled low limit of detection (LOD) (0.3-0.7 mg/L). Repeatability of both methods was acceptable (relative standard deviation of peak area were <6%). Additionally, the amount of flavonoids in a real sample of the dried herbal drug was determined.