RESUMEN
The present study is to develop an HPLC-ELSD method for simultaneous determination of three pairs of triterpenoid isomers, Ilexsaponin A₁, Ilexhainanoside D, Ilexgenin A, 3β, 19α-dihydroxyolean-12-ene-24, 28-dioic acid (ilexhainanin E) ursolic acid and oleanic acid in the leaf of Ilex hainanensis, which could provide evidence to the quality control of this herb. The six constituents were measured on a Waters XBridge C₁₈ column (4.6 mm×250 mm, 5 μm), with a mobile phase consisting of methanol (A)- 0.5% formic acid in water (B) at a flow rate of 1.0 mL·min⁻¹ (0-18 min，70%-85% A，18-20 min，85%-95% A；20-35 min，95% A). The carrier gas was N₂, and the pressure was 2.8 L·min⁻¹. The drift tube in this experiment were set at 70 °C. The injection volume was 10 μL. The contents of the six triterpenoids in 6 samples were 3.7-8.5, 10.3 -22.1, 2.8-5.9, 7.8-14.1, 2.6-3.8 and 8.8-11.9 mg·g⁻¹, respectively. The established method is proved to be accurate and sensitive for the determination of triterpenoids in Ilicis Hainanensis Folium, and may be used for the quality improvement of this herb.