Determination of bulleyaconitine A in human plasma by liquid chromatography–electrospray ionization tandem mass spectrometry

A sensitive and specific high-performance liquid chromatography (HPLC)–electrospray ionization tandem mass spectrometry (MS–MS) was developed for the determination of bulleyaconitine A (BLA) in human plasma. BLA and internal standard (I.S.) ketoconazole were extracted from the plasma by a liquid–liquid extraction. The supernatant was evaporated to complete dryness and reconstituted with acetonitrile containing 0.1% acetic acid before injecting into an ODS MS column. The gradient mobile phase was composed of a mixture of acetonitrile (containing 0.1% acetic acid, v/v) and 0.1% acetic acid aqueous solution eluted at 0.3 ml/min. BLA and I.S. were determined by multiple reaction monitoring using precursor → product ion combinations at m/z 644.6 → 584.3 and 531.2 → 81.6, respectively. Linearity was established for the concentration range of 0.12–6 ng/ml. The recoveries of BLA ranged from 96.93 to 113.9% and the R.S.D. was within 20%. The method is rapid and applicable to the pharmacokinetic studies of BLA in human.