2.4. Analysis of artemisinin by HPLC-photodiode array detection
Samples extracted with petroleum ether by refluxing, Sohxlet extraction in water and partitioned with petroleum ether, and by pressurized liquid extraction (PLE) and dried in a fume hood overnight were reconstituted in 20 mL of acetonitrile. Acetonitrile reconstitutions were filtered through 0.45 μm nylon filters attached to syringes and quantified by HPLC with photodiode array detection (Ferreira and Gonzalez, 2008).