[Grades evaluation of Scrophulariae Radix pieces based on quality constant].

The quality constant evaluation method was applied in the grade evaluation of Scrophulariae Radix pieces. Nineteen batches of Scrophulariae Radix were measured for the appearance index. Harpagide and harpagoside were taken as index components for the content determination. The traditional grading standard and the modern quality control index were combined to calculate the quality constant and grade Scrophulariae Radix pieces. The results showed that the quality constants ranged between 156. 75 and 491. 65; according to the percentage mass constants,more than 80% were graded as first-class pieces,50%-80% were graded as second-class pieces,and the rest were graded as third-class pieces. The quality constants of first-class Scrophulariae Radix were >393. 32,that of second-class Scrophulariae Radix was between 245. 83 and 393. 32,and that of third-class Scrophulariae Radix was < 245. 83. The study shows that this method can objectively,reasonably and effectively classify Scrophulariae Radix pieces,and further promote and apply the evaluation method of slice model quality constant to prove the rationality,scientificity and practicability.