Simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma by UPLC-MS/MS and its application to a pharmacokinetic study after administration of Reduning injection.

A simple, specific and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established and validated for simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma using puerarin as an internal standard (IS). Plasma samples were pretreated by a one-step direct protein precipitation procedure with acetonitrile after acidified using as little as 50 μL plasma. Chromatographic separation was performed on an Acquity BEH C18 column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.2 mL/min by a gradient elution, using 0.2% acetic acid-methanol as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with negative ion mode. Calibration curves showed good linearity (r > 0.995) over wide concentration ranges. The intra- and inter-day precisions were <15%, and the accuracy was within ±8.0%. The validated method was successfully applied to a pharmacokinetic study of the four bioactive components in rats after intravenous administration of Reduning injection.