Quality control of Chinese medicinal preparations LC/ESI(+)/MS/MS analyses of saikosaponins-a and -c as markers of Bupleuri radix samples.

We have used LC/ion trap tandem MS analysis to determine saikosaponin-a and -c as target markers in crude 70% methanol extracts from three different species of Bupleuri radix and the 10 most-popular Chinese medicinal preparations containing "Chaihu" (B. radix) without any clean-up. The optimal ionization characteristics were obtained when using positive-ion electrospray ionization (ESI) with 50 microM sodium acetate as an additive in the mobile phase.

Analysis of aristolochic acid in nine sources of Xixin, a traditional Chinese medicine, by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry.

Aristolochic acid I (AA-I), which is a known nephrotoxin, is found in a commonly used Chinese medicine, Xixin, that originates from nine Asarum species (Aristolochiaceae) found in China. A method has been developed using reversed-phase liquid chromatography coupled with atmospheric pressure chemical ionization (APCI) tandem mass spectrometry under the positive ion detection mode [LC/(+)APCI/MS/MS] to determine the amount of AA-I in Xixin. The limit of detection of AA-I, estimated by monitoring with LC/MS/MS, was at the low microg/l level.