Objective: To optimize the water extracting technology for Pingzhi capsule and establish a ultraviolet spectrophotometric method for the determination of total anthraquinones in Pingzhi capsule.Method: The extracting technology of Pingzhi Capsule was optimized by orthogonal experiment with total anthraquinones and the yield of extrac as the markers.Color reaction(Borntragers reaction) occurs sensitively when anthraquinones are in the albaline solution

producing stably red or purple-red color.The absorption value of the colored sample solution was measured at 524 nm.Results: The optimum extracting condition was adding 10 times water and extracting 1.5h/time for 3 times.The calibration curve indicated that the absorptivity was linearly correlated with the concentration of 1

8-dihydroxy anthraquinone in the range of 3.2～16 μg·mL-1(r=0.999 6). The average recovery of 1

8-dihydroxy anthraquinone was 99.17% and RSD was 2.01%.Conclusion: The technology is stable and easy to be operated.The method of direct ultraviolet spectrophotometry is accurate

sensitive

quick and cost effective and it can be used to determine total anthraquinones in Pingzhi capsule.