Fingerprint analysis of Zhimu-Huangbai herb pair and simultaneous determination of its alkaloids, xanthone glycosides and steroidal saponins by HPLC-DAD-ELSD

AIM: To develop and validate a high performance liquid chromatography(HPLC) coupled with diode array and evaporative light scattering detectors(DAD-ELSD) method for the quantitative determination and fingerprint analysis of ten active constituents in three chemical classes(namely, xanthone glycosides, steroidal saponins, and alkaloids) in Zhimu-Huangbai herb pair(ZB). METHOD: Chromatographic separation was performed on a Diamonsil C18 column(4.6 mm × 250 mm, 5 μm, Dikma) by gradient elution using acetic acid in acetonitrile solution at a flow rate of 1.0 mL·min–1 at 260 nm. The drift tube temperature of ELSD was set to 60 ℃ and nebulizer gas pressure was 4.0 Bar. Method validation was performed to assure its linearity, limits of detection and quantification, precision, repeatability, stability, and accuracy. RESULTS: The HPLC-DAD-ELSD method allowed the quantification of ten compounds(phellodendrine, jatrorrhizine, palmatine, berberine, neomangiferin, mangiferin, timosaponin E-I, timosaponin B-II, timosaponin B, and timosaponin A-III), and was successfully applied to fingerprint analysis for ten batches of ZB samples. CONCLUSION: This was the first time to apply the combination of DAD and ELSD for the simultaneous determination of ten active ingredients in ZB. The results showed that the combination of quantitative analysis for marker ingredients and chemical fingerprint for the TCM herb pair provides a potentially powerful, widely introduced, and internationally accepted strategy for assessment of complex TCM formulas.