Rapid and sensitive HPLC-MS/MS method for quantitative determination of lycorine from the plasma of rats

A simple, rapid and sensitive high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed and validated for determining lycorine in rat plasma. Plasma samples were prepared by a simple protein precipitation with methanol containing dextrorphan as internal standard. The chromatographic separation was performed on a Kromasil 60-5CN column (3 μm, 2.1 mm × 150 mm) with the mobile phase of methanol/water (containing 0.1% formic acid) (40:60, v/v) at a flow rate of 0.2 mL/min, the total analytical runtime was 5 min. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 288.1→147.1 for lycorine and m/z 258.1→157.2 for dextrorphan, respectively. The calibration curve was linear over the range of 1-1000 ng/mL with the lower limit of quantification of 1 ng/mL for lycorine. The intra- and inter-day precision (R.S.D.%) were less than 8.5% and accuracy (R.E.%) was within ±7.0%. Lycorine was sufficiently stable under all relevant analytical conditions. This method was successfully applied to the pharmacokinetic study of lycorine in rats after intraperitoneal administration with different doses of 5, 10 and 20 mg/kg.