Determination Method of Starch Content in Chinese Medicine Water Extract： Comparative and Improvement

OBJECTIVE To establish a rapid and accurate method for determination of starch content in Chinese medicine water extract. METHODS In this study， the starch content assay kit method was optimized for the traditional Chinese medicine water extraction system and the methodology was investigated. Then the starch simulation solution was taken as the research object. The content measurement results of three methods including iodine colorimetry， enzymatic hydrolysis method and the optimized starch content assay kit method were compared. RESULTS The optimized starch content assay kit method has good reproducibility and stable test results. The precision tests showed a relative standard deviation (n=6) of 1.91%. The accuracy test relative standard deviations (n=6) of the starch simulated solution and the aqueous extract were 1.82%~4.32%. The average recovery sampling rate of starch sample were 99.18%~104.41%， and the relative standard deviations (n=9) were 2.33%~4.94%. The best method was the optimized starch content assay kit method. CONCLUSION It shows that the optimized starch content assay kit method has good precision and accuracy， can be used as a detection method for determination of starch content in Chinese medicine water extract.