CD-MEKC method to analyze triterpene acids in traditional chinese medicines

a cyclodextrin-modified micellar electrokinetic chromatographic (cd-mekc) method was developed to separate and determine betulinic acid (ba), oleanolic acid (oa) and ursolic acid (ua) in traditional chinese medicines (tcms). three pentacyclic triterpene acids were baseline seperated in the buffer (ph 9.0) of 6% (v/v) methanol containing 10 mmol l-1 disodium tetraborate, 10 mmol l-1 sodium dihydrogen phosphate, 50 mmol l-1 sodium dodecylsulfate, 15 mmol l-1 2-hydroxypropyl-β-cyclodextrin within 15 min. the good linear relationships between the peak area and concentration were obtained in the ranges of 16.5-330 μg ml-1, 18-360 μg ml-1 and 19.5-390 μg ml-1 for ba, oa and ua, respectively. compared with high performance liquid chromatography with γ-cd as chiral mobile phase additive (cmpa-hplc), cd-mekc has better analytical efficiency for three acids, and the analytical time (15 min) was shorter than that of cmpa-hplc (80 min).