Abstract

A simple, accurate and sensitive liquid chromatography–mass spectrometry (LC–MS) method was established and validated for the simultaneous determination of schisandrin and gomisin A in rat plasma. The analytes of interest were extracted from rat plasma samples by diethyl ether and performed on Hypersil-C₁₈ (150 mm × 4.6 mm, 5 mm) with the mobile phase of methanol –water (72:28). The analytes were monitored with positive atmospheric pressure chemical ionization (APCI) by selected ion monitoring (SIM) mode. The target ions were m/z 415.00 for schisandrin, m/z 399.00 for gomisin A and m/z 284.90 for internal standard (IS) diazepam. The calibration curves were linear over the range 5.0 to 2000 ng·mL^-1 for schisandrin and 5.0 to 250 ng·mL^-1 for gomisin A. The lower limit of quantifications (LLOQs) for the two lignans were 5.0 ng·mL^-1. The validated method was successfully applied to the pharmacokinetic study of schisandrin and gomisin A in rat plasma after oral administration of Zaoren-an-shen granule.

Key words: Column liquid chromatography-mass spectrometry, pharmacokinetic study, schisandrin and gomisin A, Zaoren-an-shen granule.