Quantitative determination of atractylenolide III in rat plasma by liquid chromatography electrospray ionization mass spectrometry

Atractylenolide III is a major active component in Atractylodes macrocephala. This paper describes a simple, rapid, specific and sensitive method for the quantification of atractylenolide III in rat plasma using a liquid-liquid extraction procedure followed by liquid chromatography mass spectrometric (LC-MS) analysis. A Kromasil 3.5 μm C₁₈ column (150 mm × 2.00 mm) was used as the analytical column. Linear detection responses were obtained for atractylenolide III concentration ranging from 5 to 500 ng mL^-1. The precision and accuracy data, based on intra-day and inter-day variations over 5 days were within 10.29%. The lower limit of quantitation for atractylenolide III was 5 ng mL^-1, using 0.1 mL plasma for extraction and its recoveries were greater than 85% at the low, medium and high concentrations. The method has been successfully applied to a pharmacokinetic study in rats after an oral administration of atractylenolide III with a dose of 20.0 mg kg^-1. With the lower limits of quantification at 5 ng mL^-1 for atractylenolide III, this method was proved to be sensitive enough for the pharmacokinetics study of atractylenolide III.