title: On-line coupling of dynamic microwave-assisted extraction with high-performance liquid chromatography for determination of andrographolide and dehydroandrographolide in Andrographis paniculata Nees.
abstract: A novel technique based on dynamic microwave-assisted extraction (DMAE) coupled on-line with high-performance liquid chromatography (HPLC) through a flow injection interface has been developed for determination of andrographolide and dehydroandrographolide in Andrographis paniculata Nees. A TM(010) microwave resonance cavity built in the laboratory was applied to concentrating the microwave energy. An extraction vessel was placed in microwave irradiation zone. The extraction was performed in a recirculating system. When a number of extraction cycles were completed, the fractional extract (20muL) was driven to the analytical column by 65% aqueous methanol and was measured by diode array detector (DAD) at 225nm. The optimized extraction conditions are follows: extraction solvent 60% aqueous methanol; microwave forward power 80W; extraction time 6min; extraction solvent flow-rate 1.0mLmin(-1). The detection and quantification limits obtained are 0.5 and 1.7microgmL(-1) for andrographolide and 0.6 and 1.9microgmL(-1) for dehydroandrographolide, respectively. The within-day and between-day precision (RSD) are 2.1% and 3.7% for andrographolide and 1.7% and 4.1% for dehydroandrographolide, respectively. Mean recoveries for andrographolide and dehydroandrographolide are 97.7% and 98.7%, respectively. Compared with ultrasonic extraction used in the Chinese pharmacopoeia, the proposed method was demonstrated to obtain higher extraction yield in a shorter time. In addition, only small quantities of solvent (5mL) and sample (10mg) were required.
authors.affiliation: College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Ligang
authors.initials: L
authors.lastname: Chen
authors.forename: Haiyan
authors.initials: H
authors.lastname: Jin
authors.forename: Lan
authors.initials: L
authors.lastname: Ding
authors.forename: Huarong
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiupin
authors.initials: X
authors.lastname: Wang
authors.forename: Ziming
authors.initials: Z
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Chenling
authors.initials: C
authors.lastname: Qu
authors.forename: Yutang
authors.initials: Y
authors.lastname: Wang
authors.forename: Hanqi
authors.initials: H
authors.lastname: Zhang
mesh_terms: D035685:Andrographis / Q000737:chemistry*; D001331:Automation; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004224:Diterpenes / Q000032:analysis*; D000432:Methanol; D008872:Microwaves; D015203:Reproducibility of Results; D012997:Solvents; D014465:Ultrasonics
chemical_list: D004224:Diterpenes; D012997:Solvents; C030419:andrographolide; C478098:dehydroandrographolide; D000432:Methanol