Determination of Artesunate by Capillary Electrophoresis with Low UV Detection and Possible Applications to Analogues

A capillary electrophoretic method with low ultraviolet (185 nm) detection is presented for the analysis of both artesunate, a hemisuccinate ester analogue of artemisinin, and succinic acid without prior derivatization. Artesunate is easily separated from its ester hydrolysis products, succinic acid and dihydroartemisinin, with the use of phosphate electrolytes at neutral pH, and this makes the method suitable for ester stability monitoring or quality control purposes. Sensitivity is shown to be strongly influenced by electrolyte and sample matrix ionic concentration ratio, which illustrates the need for careful selection of the electrolyte when direct injection of isotonic sample solutions is considered. Alkaline derivatization, which is known to generate charged compounds, is found to be useful for the analysis of neutral artemisinin derivatives, as exemplified by experiments with dihydroartemisinin.