Objective: To establish a HPLC method for simultaneously determining three components in Zhibai Dihuang pills

i.e. morroniside

loganin and paeonol. Method: The Phenomenex C18 column (4.6 mm×250 mm

5 μm) was adopted and eluted in gradient (0-5 min

5%-7%A;5-26 min

7%A;26-45 min

7%-20%A;45-55 min

20%-60%A;55-65 min

60%A) with the mobile phase of acetonitrile (A)-0.3% phosphoric solution (B). The flow rate was 1 mL · min-1. The column temperature was 40 ℃. The detection wavelength was set at 240 nm for morroniside and loganin in the first 45 minutes

and then switched to 274 nm for paeonol between the 46 and 65 minutes. Result: The linear ranges of morroniside

loganin and paeonol were between 0.055 5-1.11 μg (r=0.999 9)

0.076 4-1.528 μg (r=0.999 9)

0.098 2-1.964 μg (r=0.999 9)

respectively. The average recoveries of morroniside

loganin and paeonol were 100.6%

101.6% and 101.9%

respectively

and the relative standard deviations were 2.5%

1.8% and 1.5%

respectively. Conclusion: This method is simple

accurate and highly reproducible and so can be used to control the quality of Zhibai Dihuang pills.