Determination of berberine, palmatine and jatrorrhizine in rabbit plasma by liquid chromatography-electrospray ionization-mass spectrometry.

Incurred rabbit plasmas samples were utilized for method quality assessment in this study, where an optimized protein precipitation method for the preparation of rabbit plasma samples and a rapid and sensitive liquid chromatography-electrospray ionization-mass spectrometry for the simultaneous determination of berberine, palmatine and jatrorrhizine was described. Plasma samples (100 μl) were pretreated by protein precipitation with the mixture of 3% formic acid and 50 ng/ml clozapine (internal standard) in acetonitrile followed by LC analysis using a C(18) column and a mobile phase composed of 0.4% formic acid solution and 0.2% formic acid solution of methanol (60:40, v/v) operated at a flow rate of 0.4 ml/min. The analysis was performed in the multiple reaction monitoring mode via electrospray ionization source operating in the positive ionization mode. The method was linear over the concentration range of 0.1-400 ng/ml for all target components. The lower limits of quantification were 0.1 ng/ml for all analytes, all intra- and inter-day precision values were less than 7.10%, and accuracy (bias, %) was within ±7.11%. The mean absolute recovery was more than 72% for all analytes. The validated method has been successfully applied to the pharmacokinetic study of berberine, palmatine and jatrorrhizine in rabbit plasma after oral administration of San-Huang decoction to rabbits.