[Determination of oleanolic acid in Achyranthes bidentata BLume and its preparations by supercritical fluid chromatography].

Capillary SFC was used for the determination of oleanolic acid in Achyranthes bidentata BLume and its preparations Tianmawan, Jinguishenqiwan and Hechedazaowan. The amount of oleanolic acid in the root of Achyranthes bidentata BLume was 1.75-2.19% (mean +/- SD = 1.94 +/- 0.17%). The limit of detection was 9.605 x 10(-11) g. The method is highly sensitive, accurate, reproducible, simple, rapid and specific, so, it can be extensively used for the determination of other preparations and crude herbs.