Determination of Lupenone and β-Sitosterol in Rhizoma Musae by UPLC with DAD and ELSD

Rhizoma Musae has been used for centuries in Miao medicine practice in China, and it usually uses for treating diabetes and bruises. In this study, lupenone and β-sitosterol in Rhizoma Musae were separated by reversed-phase ultra-performance liquid chromatography (RP-UPLC) and simultaneously detected by a diode array detector (DAD) and an evaporative light scattering detector (ELSD) using methanol and 0.1% aqueous acetic acid (100 : 4, v/v) as a mobile phase in 20 min. The flow rate of 0.1 mL/min was set with isocratic, the temperature of column compartment maintained at 50°C and ultraviolet detection set at 206 nm wavelength. The injection volume was 1.0 µL. The parameter for the ELSD was set to a probe temperature of 45°C, and the nebulizer for nitrogen gas was adjusted to 1.5 L/min. The RP-UPLC method was validated for accuracy, precision, limit of detection and limit of quantification. It applied to the quantification of the active chemical constituents of Rhizoma Musae, and results indicated that both DAD and ELSD were suitable for the determination of lupenone and β-sitosterol, and the DAD has a better sensitivity than the ELSD.