Quantification of isoflavonoids and triterpene saponins in Astragali Radix, the root of Astragalus membranaceus, via reverse-phase high-performance liquid chromatography coupled with integrated pulsed amperometric detection

Abstract Astragali Radix, the root of Astragalus membranaceus Bunge, is one of the most frequently used crude drugs in Asian medicine. We developed a quantification method for 6 components (calycosin, formononetin, astragaloside I–IV) of Astragali Radix and Hwanggi-gyeji-omul-tang (HGOT) using reverse-phase high-performance liquid chromatography coupled with integrated pulsed amperometric detection (RP-HPLC-IPAD). The plants were extracted in 80% ethanol for 2 h. All target components were detected with good sensitivity using sodium hydroxide (as a post-column eluent). The limit of detection (S / N  =  3) and limit of quantification (S / N  =  10) of the target components ranged from 0.10–1.00 ng and from 0.30–3.00 ng, respectively. The coefficients of linear regression ranged from 0.9993–1.0000, all interday and intraday precision values were