An ultra-high performance chromatographic method for the determination of artemisinin

Objective: The goal of this study is to develop an ultra-high performance liquid chromatographic method for the quantitative determination of artemisinin at very low concentrations using selective ion mass spectroscopic detection. Materials and methods: Separation was conducted using a C4 100mm x 2.1mm column, and the mobile phase consisted of an isocratic two-component system consisting of 60% of a 0.1% aqueous solution of formic acid and 40% acetonitrile at a flow rate of 0.4 ml/min. The drug was detected by means of an electrospray mass spectrometer with selective ion monitoring of the [M-H2O+H](+) with m/z of 265.3 in positive ion mode. Results: The calibration curves of artemisinin obtained from the UPLC/MS system were linear in the three ranges analyzed, with a correlation coefficient of no less than 0.9996 for all sets of standards. The peak tailing factor for all measurements were <= 1.7. The method proved to have good repeatability and linearity. Discussion: The described analytical method reached a LOQ of 0.010 mu g/ml with an isocratic system and enables an analysis rate of 20 samples per hour. The linearity of the standards was excellent for all sets of standards analyzed. Conclusion: The method presented in this study provides a rapid and suitable means for the determination of artemisinin at very low concentrations. This is especially significant when performing dissolution studies where, due to the low solubility of artemisinin, a method that can measure the drug at nanogram levels is necessary.