A high‐performance liquid chromatography/tandem mass spectrometry method for the determination of artemisinin in rat plasma

Artemisinin is a widely used antimalarial drug. To evaluate the pharmacokinetics of artemisinin in rats, a sensitive and specific liquid chromatography/tandem mass spectrometric (LC/MS/MS) method was developed and validated for the determination of artemisinin in rat plasma. For detection, a Sciex API 4000 LC/MS/MS instrument with an electrospray ionization (ESI) TurboIonSpray inlet in the positive ion multiple reaction monitoring (MRM) mode was used to monitor precursor ([M+NH 4 ] + ) → product ions of m/z 300.4 → 209.4 for artemisinin and m/z 316.4 → 163.4 for artemether, the internal standard (IS). The plasma samples were pretreated by a simple liquid‐liquid extraction with ether. The standard curve was linear ( r  > 0.99) over the artemisinin concentration range of 1.0–200.0 ng/mL in plasma. The method had a lower limit of quantification of 1.0 ng/mL for artemisinin in 100 µL of plasma, which offered a satisfactory sensitivity for the determination of artemisinin. The intra‐ and inter‐day precisions were measured to be within ±5.3% and accuracy between −2.6% and 1.2% for all quality control samples, lower limit of quantification and upper limit of quantification samples. The extraction recoveries of artemisinin and the IS were 95.4 ± 4.5% and 92.8 ± 3.9%, respectively. This present method was successfully applied to the characterization of the pharmacokinetic profile of artemisinin in rats after oral administration. Copyright © 2006 John Wiley & Sons, Ltd.