A Simple Differential Pulse Polarographic Method for the Determination of Artemisinin in Artemisia Annua

Abstract

A reliable and simple differential pulse polarographic method is presented for the determination of the antimalarial artemisinin in Artemisia annua. The polarographic behaviour of artemisinin was examined in various buffer systems over the pH range 2–10. Artemisinin was irreversibly reduced at the dropping mercury electrode. In 0.1 M KH₂PO₄, pH 5.5, mixed with methanol (7:3; v/v), the differential pulse polarograms exhibited reproducible peaks at 0.0 V vs. Ag/AgCl and a plot of peak height against concentration of artemisinin was found to be linear over the range 6.4 × 10⁻⁷ - 3.2 × 10⁻⁵ mol/L (R = 0.9998). The detection limit was calculated to be 58 ng/mL. The polarographic method was applied to the determination of the content of artemisinin in the traditional Chinese herbal drug Artemisia annua L. by using the standard addition method. The proposed DPP method is sensitive, precise and time-efficient and is, therefore, suitable for quantitative analysis of artemisinin in plant extracts.