Determination of oleanolic acid in oleanolic acid tablets by HPCE

Objective To establish an HPCE method for rapid monitoring the content of oleanolic acid in oleanolic acid tablets.Methods Samples were analyzed on a fused and uncoated silic capillary of 75 μm×50 cm(40 cm of effective length).20 mmol·L-1 of borax containing 5% methanol was used as running buffer.Samples were injected hydrodynamically(5 s,3.0 kPa) into the capillary.The applied voltage was 25 kV and the detection wavelength was set at 200 nm.The temperature was kept at 25 ℃.The running time was 10 min.Results The calibration curve was linear in the range of 2.58-660 μg·mL-1(r=0.9997) for oleanolic acid.The average recovery(n=6) was 99.47% with RSD 1.28%.Conclusion This method is accurate,rapid,and simple for the content determination of oleanolic acid.