[Determination of active anthraquinones in Rheum and its tea preparations by micellar electrokinetic capillary electrophoresis].
OBJECTIVE
To establish an instant determination method of emodin, aloe-emodin and rhein, from Rheum, and one of their preparations, Qinghai Wild Dahuang Tea, by micellar electrokinetic capillary electrophoresis for the first time.


METHODS
Separation was carried out in an uncoated fused silica capillary (75 microm x 50.0 cm). Meanwhile, a running voltage 20 kV, 15.0 mmol x L(-1) borax buffer with 30.0 mmol x L(-1) SDS and 10% ethanol (pH 9.60) and a UV detector at 254 nm were adopted.


RESULTS
The linear calibration rang was 4-120 mg x L(-1) (r = 0.992 1) for emodin, 10-200 mg x L(-1) (r = 0.997 0) for aloe-emodin, and 2-100 mg x L(-1) (r = 0.997 1) for rhein, respectively. Under the optimum conditions, the relative standard deviation (RSD) values (n = 6) for the migration time and the peak area of each peak were 0.59%-0.80%, 1.30%-3.22%, respectively. The contents of the analytes were easily determined with recoveries ranging from 97.6%-102.3%.


CONCLUSIONS
The method is proved to be simple, rapid and accurate, and can be used for the quality control of medicinal herb, Rheum, and its tea preparation.
Zheng
Wen-jie
WJ
School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200030, China. zhengwj@sjtu.edu.cn
Chen
Xing-guo
XG
Jia
Wei
W
D000880:Anthraquinones / Q000032:analysis*; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods; D004642:Emodin / Q000032:analysis*; D028321:Plant Preparations / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012250:Rheum / Q000737:chemistry*
D000880:Anthraquinones; D028321:Plant Preparations; C518327:aloe emodin; D004642:Emodin; C020491:rhein