Simultaneous determination of 6 compounds in Rehmanniae Radix by dual-wavelength HPLC

OBJECTIVE To establish a dual-wave length HPLC method for the determination of 6 components in Rehmanniae Radix (including catalpol, rehmannioside D, rehmannioside A, leonuride, acteoside and isoacteoside). METHODS Neptune C₁₈ column(4.6 mm×250 mm, 5 μm) was selected for separation with acetonitrile-0.1% phosphoric acid solution as the mobile phase for gradient elution, the flow rate was 1.0 mL·min^-1, the column temperature was maintained at 30 ℃ and the detection wavelength was set at 203 nm for catalpol, rehmannioside D, rehmannioside A and leonuride, 334 nm for acteoside and isoacteoside. RESULTS Six components showed good linear relationships(r>0.9990) in their own ranges. The average recoveries at three levels ranged from 96.33% to 98.55% with RSD of 0.97% to 1.45%. CONCLUSION This method is simple, accurate, reliable, stable and reproducible, which can be used for the quality control of Rehmanniae Radix.