Pressurized liquid extraction of berberine and aristolochic acids in medicinal plants.

Berberine and aristolochic acids I and II present naturally in medicinal plants were extracted using a laboratory-made pressurized liquid extraction (PLE) system in the dynamic mode. As the target analytes were present naturally in the medicinal plants, spiking was not done and comparison with ultrasonic extraction and Soxhlet extraction was performed to assess the method accuracy. The effect of temperature, volume of solvent required and particle size were investigated. Method precision (RSD, n=5) between 1.98 and 3.4% was achieved for the extraction of berberine and aristolochic acids I and II in medicinal plants and lower than 8% for lower levels of aristolochic acid II in medicinal plants.