Determination of astragaloside IV in Radix astragali from various habitats by HPLC-ELSD

Objective: To determine the content of astragaloside Ⅳ in Radix astragali from various habit- ats. Methods :The content of astragaloside Ⅳ was determined by high-performance liquid chromatography with evaporative light-scattering detection ( HPLC-ELSD ) ;The chromatography condition was as follows: Kromasil C18 column (4.6mm×250mm, 5μm) ; mobile phase was CH3CN-H2O(38∶62); flow speed was 1.0 mL·min-1; temperature of column was room temperature; and the injection volume was 10μL.The ELSD conditions were as follows: the temperature of drift tube was 45℃ , the gas pressure was 2. 02 bar. Results : The calibration curveswere linear in the range of 2.0~10.0μg( r =0.9995). The precision (RSD) was 1.30%. The stability (RSD) was 1.71% in 24 h and the recurrence(RSD) was 1.28%. The recovery was 102.10% (RSD=1.56%) for astragaloside Ⅳ. Conclusion :HPLC-ELSD is a simple and reliable method to determine the content of astragaloside Ⅳ in Radix astragali. The content of astragaloside Ⅳ in Radix astragali had great changes between the various habitats, the content of astragaloside Ⅳ in gansu Radix astragali were the most.