Separation of isomeric bavachin and isobavachalcone in the F ructus P soraleae by capillary electrophoresis–mass spectrometry

Bavachin and isobavachalcone are the isomeric compounds in the F ructus P soraleae. The ion trap mass spectrometric fragmentation pathways of the bavachin and isobavachalcone in negative ion mode were elucidated for the identification. A novel method for determination of isomeric bavachin and isobavachalcone has been developed by capillary electrophoresis coupled with mass spectrometric detection. The effects of several factors such as concentration, p H of ammonium acetate buffer, separation voltage, composition and flow rate of the sheath liquid were investigated. Under optimal conditions, the linear concentration range for bavachin and isobavachalcone were 0.8–100 μg/m L with the correlation coefficient of 0.996 and 0.995, respectively. Relative standard deviations of migration time and peak areas were lower than 5%. The limits of detection (signal/noise = 3) were 60 ng/m L . The proposed method can be successfully applied to the determination of bavachin and isobavachalcone in the F ructus P soraleae and six F ructus P soraleae‐containing preparations.