Objective: To compare contents of norepinephrine and dopamine in fresh and dry Portulacae Herba. Method: HPLC-UV method was adopted for determination of norepinephrine and dopamine in fresh and dry Portulacae Herba.This analysis was performed on a Alltima C18 column(4.6 mm×250 mm

5 μm)

column temperature was set at 25 ℃

flow rate was 0.8 mL·min-1

detection wavelength was kept at 280 nm

mobile phase consisted of methanol-water(70:30

containing 30 mmol·L-1 sodium dodecyl sulfate and 0.02 mol·L-1 phosphate buffer with pH of 3.2). Result: Separation of norepinephrine and dopamine was well in HPLC

these two alkaloids showed a good linear relationship in 52.5-157.5 mg·L-1 and 64.7-194.1 mg·L-1

respectively.Contents of norepinephrine and dopamine in fresh Portulacae Herba were 0.070% and 0.50%;while contents of them in dry Portulacae Herba were 0.015% and 0.20%

respectively. Conclusion: Contents of norepinephrine and dopaminein in fresh herbs are significantly higher than these in dry herbs.This paper provides experimental basis for reasonable application of Portulacae Herba.