Abstract: A method for the simultaneous determination of berberine, palmatine, matrine, catechin and baicalin in Funing Shuan was established using micellar electrokinetic capillary chromatography-electrospray ionization mass spectrometry (MEKC-ESI MS). The compounds were separated on an uncoated capillary (80 cm×50 μm) with the operating voltage of 25 kV and the running buffer of 40 mmol/L lauric acid-100 mmol/L ammonia mixture containing 25% acetonitrile (pH 9.5). The baseline separation of the five compounds was achieved within 16 min with a satisfactory repeatability and sensitivity. The solution of 50% 2-propanol/water solution (containing 3 mmol/L acetic acid) was used as the sheath liquid for the ESI MS analysis. The results showed that the linear ranges for berberine, palmatine, matrine, catechin and baicalin were 0.03~15, 0.05~15, 0.2~250, 1.5~300 and 2.0~500 mg/L, respectively, and the detection limits were 0.01, 0.02, 0.05, 0.5 and 0.6 mg/L, respectively. The average recoveries of the five components were between 94.0%~104.0% with the relative standard deviations (RSDs) of 0.3%~3.2%. The developed method is simple, rapid, and accurate, and it is suitable for the routine analysis of the five effective components in Funing Shuan.

Key words: baicalin, berberine, catechin, Funing Shuan , matrine, palmatine, micellar electrokinetic capillary chromatography-electrospray ionization mass spectrometry (MEKC-ESI-MS)