Fast simultaneous detection of three diterpenoids in Herba Siegesbeckiae using solid phase extraction followed by HPLC-UV with a core–shell particle column

To quickly determine the amounts of kirenol, darutoside and darutigenol in Herba Siegesbeckiae using HPLC, the efficiency of sample cleanup with different solid phase extraction methods was systematically investigated. The results showed that a polymer based strong anion exchange (P-SAX, 200 mg/6 mL) sorbent could separate and enrich diterpenoids providing rapid determination without impurity interference. In this paper a new HPLC-UV method using a core–shell column (Boltimate C18 3.0 × 100 mm, 2.7 μm) for the quantitative determination of three diterpenoids was developed. Under optimum experimental conditions, P-SAX pretreatment with a core–shell analytical column exhibited satisfactory results in the determination of diterpenoids in Herba Siegesbeckiae with recovery rates of 95–102%, relative standard deviations below 1.1%, a limit of quantitation as low as 0.1 6 μg mL−1, and a short analytical runtime of 8 min. Finally, the proposed method was successfully applied in the profiling of diterpenoids in Herba Siegesbeckiae from different regions.