On-line coupling of dynamic microwave-assisted extraction with high-performance liquid chromatography for determination of andrographolide and dehydroandrographolide in Andrographis paniculata Nees.
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.
Chen
Ligang
L
College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Jin
Haiyan
H
Ding
Lan
L
Zhang
Huarong
H
Wang
Xiupin
X
Wang
Ziming
Z
Li
Juan
J
Qu
Chenling
C
Wang
Yutang
Y
Zhang
Hanqi
H
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
D004224:Diterpenes; D012997:Solvents; C030419:andrographolide; C478098:dehydroandrographolide; D000432:Methanol