title: New and simple methylene blue colorimetric assay for glycyrrhizin in pharmaceuticals.
abstract: A new colorimetric method for glycyrrhizin in licorice and drug preparations is given. The method is based on coupling the acidic genin, glycyrrhetinic acid, with methylene blue and measuring the extinction of the coupled compound solution in chloroform-alcohol.
mesh_terms: D003124:Colorimetry; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008722:Methods; D008751:Methylene Blue; D004364:Pharmaceutical Preparations / Q000032:analysis
chemical_list: D004364:Pharmaceutical Preparations; D006034:Glycyrrhetinic Acid; D008751:Methylene Blue