Determination of dihydroartemisinic acid in Artemisia annua L. by gas chromatography with flame ionization detection
Dihydroartemisinic acid (DHAA) is the direct precursor to artemisinin, an effective anti-malaria compound from Artemisia annua L. (A. annua), and it can be transformed to artemisinin without the catalysis of enzyme. A rapid and sensitive analysis of DHAA in A. annua is needed to screen excellent plant resources aimed to improve artemisinin production. In order to develop a rapid and sensitive determination method for DHAA in plant, the extraction and analysis conditions were extensively investigated in the present work. As a result, extraction of powdered A. annua leaves at 55 °C for 50 min with chloroform resulted in the highest yield of DHAA, with a recovery of more than 98%. The precision of this gas chromatographic procedure ranged from 1.22 to 2.94% for intra-day and from 1.69 to 4.31% for inter-day, respectively. The accuracy was 99.55-103.02% for intra-day and 98.86-99.98 % for inter-day, respectively. The measured LOQ and LOD values of the proposed method reached 5.00 and 2.00 µg/mL, respectively. Validation indicated the method was robust, quick, sensitive and adequate for DHAA analysis.