[Determination of three constituents in Radix Astragali by HPLC-MS].

Aim: To determine calycosin-7-O-beta-D-glucoside, astragaloside IV and formononetin in Radix Astragali and other relative samples by HPLC-MS.

Methods: HPLC was carried out with Agilent 1100LC/MSD, equipped with Agilent Zorbax SB C18 column (250 mm x 4.6 mm ID, 5 microm) and mass spectrum detector. The mobile phase (CH3CN-H2O) was eluted in gradient mode.

Results: The calibration curves of calycosin-7-O-beta-D-glucoside, astragaloside IV and formononetin were linear in the range of 0.03 - 1.21 microg x mL(-1), 0.35 - 13.86 microg x mL(-1) and 0.38 - 15.22 microg x mL(-1), respectively. These recoveries of samples were from 95% to 105% with RSD less than 1.5%.

Conclusion: The method was employed to analyse 25 samples of Radix Astragali and other relative samples, including Radix Astragali slice, Radix Astragali Preparata, Hedysarum polybotrys Hand. -Mazz, Astragalus ernestii Comb. The contents of three constituents vary greatly because of the species, place of collection and season of harvesting. This method could apply to evaluate the quality of Radix Astragali and it is simple, sensitive and reliable.