Quantitative determination of sauchinone in rat plasma by liquid chromatography-mass spectrometry.

A rapid, sensitive and specific method using liquid chromatography with tandem mass spectrometric detection (LC-MS) was developed for the analysis of sauchinone in rat plasma. Di-O-methyltetrahydrofuriguaiacin B was used as internal standard (IS). Analytes were extracted from rat plasma by liquid-liquid extraction using ethyl acetate. A 2.1 mm i.d. × 150 mm, 5 µm, Agilent Zorbax SB-C(18) column was used to perform the chromatographic analysis. The mobile phase was methanol-deionized water (80:20, v/v). The chromatographic run time was 7 min per injection and the flow-rate was 0.2 mL/min. The tandem mass spectrometric detection mode was achieved with electrospray ionization interface in positive-ion mode (ESI(+) ). The m/z ratios [M + Na](+) , m/z 379.4 for sauchinone and m/z 395.4 for IS were recorded simultaneously. Calibration curve were linear over the range of 0.01-5 µg/mL. The lowest limit of quantification was 0.01 µg/mL. The intra-day and inter-day precision and accuracy of the quality control samples were 2.94-9.42% and 95.79-108.05%, respectively. The matrix effect was 64.20-67.34% and the extraction recovery was 93.28-95.98%. This method was simple and sensitive enough to be used in pharmacokinetic research for determination of sauchinone in rat plasma.