Industrial & Engineering Chemistry Research, Vol.50, No.24, 13620-13627, 2011
Design and Performance Evaluation of Ionic-Liquids-Based Microwave-Assisted Environmentally Friendly Extraction Technique for Camptothecin and 10-Hydroxycamptothecin from Samara of Camptotheca acuminata
Ionic-liquids-based, microwave-assisted extraction (ILMAE) was successfully applied to the extraction of two alkaloids: camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) from samara of Camptotheca acuminata. Ten different types of 1-alkyl-3-methylimidazolium, with different cations and anions, were investigated in this work, and 1-hexyl-3-methylimidazolium bromide ([C8MIM]Br) solution was selected as the optimal solvent. In addition, the extraction parameters, including ionic liquid concentration, soak time, microwave irradiation power, irradiation time, solid liquid ratio, and number of extraction cycles, were optimized. The optimal conditions were as follows: 0.8 M [C8MIM]Br; soak time, 2 h; microwave irradiation power, 385 W; irradiation time, 8 mm; solid-liquid ratio, 1:12 (g/mL); and two of extraction cycles. No degradation of the target analytes have been observed at the optimum conditions, as evidenced from the stability studies performed with standard CPT and HCPT. The proposed method also shows high reproducibility. Compared with the traditional methods, the proposed approach demonstrates higher efficiency in a shorter extraction time (from 4 h to 8 min), which demonstrates that ILMAE is a rapid, efficient, and simple sample extraction technique.