Packed-column supercritical fluid chromatography of artemisinin (qinghaosu) with electron-capture detection.

In this preliminary report, a supercritical fluid chromatographic method is described for the determination of artemisinin in whole blood. The chromatography is carried out on a 20 cm x 1 mm I.D. Deltabond cyano supercritical fluid chromatographic column with detection of the artemisinin via an electron-capture detector. The sample work-up uses a liquid-liquid extraction with hexane, giving a recovery of 82%. The current limit of detection using 1 ml of blood is 20 ng/ml. We speculate that the endoperoxide moiety accounts for the response to the electron-capture detector and thus provides a new approach by which this class of compounds may be analyzed.