title: Analysis of flavonoids in leaves of Adinandra nitida by capillary electrochromatography on monolithic columns with stepwise gradient elution.
abstract: Extracts of Adinandra nitida leaves, known as Shiyacha in China, were analyzed by monolithic columns of capillary electrochromatography (CEC). To obtain good resolution within a short time, stepwise gradient elution of CEC was employed, and the effects of experimental parameters, such as the buffer, the gradient conditions, and the mode of injection were studied systematically. Under optimized conditions, analysis could be accomplished in 25 min on a monolithic rod of macroporous poly(butyl methacrylate-co-ethylene dimethacrylate). With two identified flavonoids, epicatechin and apigenin, as markers, a quality control method for Shiyacha and its relevant products was established. The calibration curves exhibited good linear behavior over the concentration range of two orders of magnitude. On combination with an on-line concentration technique, the detection limit of flavonoids could be decreased to 25 ng for apigenin.
authors.affiliation: National Chromatographic Research & Analysis Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Lingyi
authors.initials: L
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.forename: Weibing
authors.initials: W
authors.lastname: Zhang
authors.forename: Yukui
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D047310:Apigenin / Q000032:analysis / Q000737:chemistry; D002392:Catechin / Q000032:analysis / Q000737:chemistry; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods* / Q000592:standards; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D007202:Indicators and Reagents; D019684:Magnoliopsida / Q000737:chemistry*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D011786:Quality Control
chemical_list: D005419:Flavonoids; D007202:Indicators and Reagents; D047310:Apigenin; D002392:Catechin