Determination of geniposidic acid in rat plasma by LC-MS/MS and its application to in vivo pharmacokinetic studies.

A simple, rapid and sensitive method for the determination of geniposidic acid (GSA) in rat plasma was developed using liquid chromatography tandem mass spectrometry (LC-MS/MS). Geniposide (GS) was used as the internal standard. Rat plasma pretreated by solid-phase extraction (SPE) was analyzed by LC-MS/MS with negative ion mode electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The analytical column was C₈ column and the mobile phase was methanol (A) and water (B). The flow rate was set at 0.8 mL/min with split ratio of 1:3, the total run time was 15 min. The MS/MS ion transitions monitored were m/z 373.3-211.1 for GSA and m/z 387.3-225.3 for GS. The quantification limit was 5 ng/mL within a linear range of 10-4000 ng/mL. The inter-day and intra-day accuracy and precision were within ±10%. The method was fully validated for its sensitivity, selectivity, matrix effect, stability study and recovery. The data indicate that our LC-MS/MS assay is an effective method for the pharmacokinetics study of GSA in rat plasma. Copyright Â