高效液相-蒸发光散射检测器测定黄芪中4种皂苷类成分

Assay of Four Saponins in Astragali Radix by HPLC-ELSD

目的考察高效液相-蒸发光散射检测器(HPLC-ELSD)测定黄芪中4种皂苷类成分时外标法与一测多评法的适用性。方法应用HPLC-ELSD,按常规外标法同时测定黄芪中丙二酰黄芪皂苷Ⅰ、黄芪皂苷Ⅰ、黄芪皂苷Ⅱ和黄芪甲苷的含量,同时以丙二酰黄芪皂苷Ⅰ为"内标",计算其与黄芪皂苷Ⅰ、黄芪皂苷Ⅱ和黄芪甲苷的相对校正因子,考察并探讨其稳定性。结果黄芪药材中黄芪甲苷含量极低,部分药材中甚至检测不到,而含量最高的为丙二酰黄芪皂苷Ⅰ和黄芪皂苷Ⅰ。用所测4种皂苷类成分在ELSD检测器上的响应值计算得到的校正因子稳定性差,不能够用"一测多评法"同时定量。结论 HPLC-ELSD外标法能够准确地测定黄芪中4种皂苷类成分的含量,而用"一测多评法"时检测器的选择需要进一步探索。

Objective To study the feasibility of high performance liquid chromatography-evaporative light scattering detector （ HPLC-ELSD） in quantitative analysis of multi-components （ QAMS） by single marker. Methods Four saponins in Astragali Radix were simultaneously determined by HPLC-ELSD using external standard method, and malonylastragaloside I served as internal standard. The relative correction factors between internal standard and astragaloside Ⅰ, astragaloside Ⅱ and astragaloside Ⅳ were calculated, and the stability was investigated. Results Astragaloside Ⅳ in Astragali Radix was little, while malonylastragalosideⅠand AstragalosideⅠwere abundant.The relative correction factors lacked stability, so ELSD could not be used in QAMS. Conclusion HPLC-ELSD can precisely determine contents of four saponins in Astragali Radix. The detector needs to be further studied when the components have poor ultraviolet absorption such as saponins by QAMS.