On-line continuous flow ultrasonic extraction coupled with high performance liquid chromatographic separation for determination of the flavonoids from root of Scutellaria baicalensis Georgi

An on-line method. based oil Coupling dynamic ultrasonic extraction (DUE). Continuously sampling the suspension of sample and solvent. high performance liquid chromatographic separation with diode array detection, has been developed for the determination of the flavonoids. including baicalin, baicalein and wogonin. from the root of Scutellaria baicalensis Georgi Variables Influencing the DUE were evaluated by orthogonal test The extraction yields of baicalin. baicalein and wogonin in the roots of S baicalensis Georgi obtained from five different cultivated areas are 73 8-131 51 mu g mg(-1) (RSD <= 6 24%). 6.8-15 9 mu g mg(-1) (RSD <= 5 36%) and 44-14 3 mu g mg(-1) (RSD <= 5 30%). respectively The limits of detection for baicalin. baicalein and wogonin are 030, 037 and 041 mu g mL(-1), respectively Linearity is from 0.55 to 1091 mu g mL(-1) for baicalin, fiom 051 to 105 mu g mL(-1) for baicalein and from 053 to 1021 mu g mL(-1) for wogonin Compared with off-line continuous flow-DUE, the proposed method Would be moie convenient for the determination of the analytes and the rapid optimization of the extraction process The exit action yields of flavonoids obtained by the proposed method are comparable with those obtained by dynamic microwave assisted extraction. static ultrasonic extraction and reflux extraction The result indicated that the proposed method IS Suitable to determine the active components in Chinese herbal medicine (C) 2010 Elsevier B V All rights reserved