Abstract: AIM: To develop a HPLC MS MS method for the determination of dihydroartemisinin in healthy human plasma.METHODS: Artemisinin was used as the internal standard.Plasma samples were pretreated by liquid-liquid extraction.Dihydroartemisinin was detected by the positive electrospray ionization-MS method under multiple reaction monitoring mode.RESULTS: The calibration curve of dihydroartemisinin in plasma was linear over the range of 1.01-2 020 ng·ml^-1 , the low limit of quantitation was 1.001±0.072 ng·ml^-1.The relative recovery was 93.0 %-98.2 %.The within-day and between-day RSDs were both less than 10 %.CONCLUSION: This assay method is accurate, sensitive, and specific, and it is suitable for the measurement of plasma concentration.

Key words: dihydroartemisinin, LC MS MS, plasma concentration