MECC determination of ursolic acid and oleanolic acid in leaf of Eriobotrya japonica

Objective:To establish an HPCE method for the determination of ursolic acid and oleanolic acid in leaf of Eriobotrya japonica.Method:The separation was performed on a fused and uncoated silic capillary of 75 μm×60 cm(50 cm of effective length).40 mmol·L~(-1) borax(pH 9.4)containing 30 mmol·L~(-1) sodium dodecyl sulfate (SDS),20 mmol·L~(-1) hydroxypropyl-β-cyclodetrin (HP-β-CD) and 5 % acetonitrile was used as running buffer.Samples were injected hydrodynamically(5 s,3.0×10~3 Pa)into the capillary.The applied voltage was 24 kV and the wavelength of detection was set at 200 nm.The temperature was kept at 25 ℃.The running time was 30 rain.Results:The calibration curves were linear in the range of 42.5-680 μg·mL~(-1) (r=0.9989) for ursolic acid and 33.0-660 μg·mL~(-1) (r=0.9994) for oleanolie acid.The average recoveries(n=5) were respectively 97.1% and 97.6% (RSD 3.3% and 2.9% )for ursolie acid and oleanolic acid.Conclusion:This method is accurate and reliable,and suitable for the determination ursolic acid and oleanolic acid in leaf of Eriobotrya japonica.