[Optimization of determination methods of astragaloside Ⅳ and analysis of contents of astragaloside Ⅳ in different origin and grade].

A rapid and accurate method for determination of astragaloside Ⅳ was established,which was further applied to determine the contents of astragaloside Ⅳ in 87 batches of different origin and different grade of Astragali Radix. The ROC curve was used to analyze the contents of astragaloside Ⅳ in different origin. Simultaneous contents of astragaloside Ⅳ in different grade were compared with chemometrics. HPLC-ELSD method was used to determine the contents of astragaloside Ⅳ. A Vensil MP C18 column( 4. 6 mm×250 mm,5 μm) was used with acetonitrile-water( 32 ∶68) as the mobile phase at a flow rateof 1 m L·min-1. The column temperature was 25 ℃ with ELSD parameters as follows: gas flow rate was 2. 5 L·min-1,the drift tube heating temperature was set to 105 ℃,and the gain value was 4. 0. The optimized method avoided the problem that the consumable quality unstable and the recovery rate was not high. The contents determined by the optimized method were higher than the pharmacopoeia method,with less time and high recovery rate. The ROC curve analysis showed that there was no significant difference of contents of astragaloside Ⅳ between the top grade of Shanxi wild-simulated Astragali Radix top and the first grade of Gansu cultivated Astragali Radix. The contents of astragaloside Ⅳ in the second,third and fourth grade of Shanxi wild-simulated Astragali Radix was significantly higher than those of produced from Gansu.There was a significant negative correlation between the contents of astragaloside Ⅳ and grade in Shanxi Astragali Radix. While there was no correlation for Gansu Astragali Radix. This study provided the basis for the quality grade standard of Astragali Radix.