Preparation and Purification of Free Anthraquinones Extracted from Rheum Studies on the Quality Standard of Dachengqitang Granule Feasibility study of QAMS for quantitative analysis of multiple structural types of ingredients in Zhizi Jinhua pill Opinion of Colon-targeting Delivery about Rhubarb Extract as a Purgative Study on determination of anthraquinones in Dachengqi Tang residues of Magnolia officinalis and Citrus aurantium removed in decoction process Study on in vitro transdermal absorption of rhubarb free anthraquinones in Dasuan Xiaohuang Pasta