MEKC-DAD fingerprint of Radix et Rhizoma Rhei MEKC-DAD fingerprint of Radix et Rhizoma Rhei Dynamic accumulation analysis on bioactive constituents of Polygonum multiflorum in different collection periods Analysis and Comparison of Flavonoids in Three Bougainvilleas by Micellar Electrokinetic Chromatography Determination of multiple functional substances in different processed products of Polygoni Multiflori Radix and principal component analysis Comparison of baicalin in skullcap polyploid determined by MEKC and HPLC Methods