Quantification of polygalasaponin F in rat plasma using liquid chromatography–tandem mass spectrometry and its pharmacokinetics application

A rapid and highly selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for determination of polygalasaponin F (PF) in rat plasma was developed and validated. The chromatographic separation was achieved on a reverse-phase Zorbax SB-C18 column (150 × 4.6 mm, 5 µm), using 2 mm ammonium acetate (pH adjusted to 6.0 with acetic acid) and acetonitrile (25:75, v/v) as a mobile phase at 30 °C. MS/MS detection was performed using an electrospray ionization operating in positive ion multiple reaction monitoring mode by monitoring the ion transitions from m/z 1091.5 → 471.2 (PF) and m/z 700.4 → 235.4 (internal standard), respectively. The calibration curve showed a good linearity in the concentration range 0.0544-13.6 µg/mL, with a limit of quantification of 0.0544 µg/mL. The intra- and inter-day precisions were <9.7% in rat plasma. The method was validated as per US Food and Drug Administration guidelines and successfully applied to pharmacokinetic study of PF in rats.