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

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.

Separation was conducted using a C4 100 mm× 2.1 mm 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.

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.

The described analytical method reached a LOQ of 0.010 µg/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.

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.