title: Application of dimethyl-beta-cyclodextrin as a chiral selector in capillary electrophoresis for enantiomer separation of ephedrine and related compounds in some drugs.
abstract: Dimethyl-beta-cyclodextrin (DM-beta-CD) modified capillary electrophoresis has been developed for chiral separation of ephedrine and related compounds, such as (+/-)-norephedrine, (+/-)-N-methylephedrine, (+/-)-ephedrine and (+)-pseudoephedrine. The influence of some crucial parameters such as buffer concentration, pH value, DM-beta-CD concentration, applied voltage and separation temperature on the separation was investigated. Under the optimum conditions, i.e. 40 mM DM-beta-CD in 75 mM Tris (pH 2.5) as the running electrolyte, separation voltage +25 kV and temperature 25 degrees C, a satisfactory separation of the enantiomers was accomplished. The detection limits (S/N = 3) ranged from 65 to 161 ng/mL and the linear range was 0.15 to 101.0 microg/mL for pressure injection. The present method was successfully applied for the analysis of a series of drugs such as anti-tussive, the drug for rheum, the drug for rhinitis and a Chinese traditional herbal medicine, Ephedrae herba (Ma-Huang in Chinese). The recoveries of ephedrine and related compounds in real samples ranged from 97.6 to 103.5%. This method is useful in the simple and rapid analysis of ephedrine derivatives in marketed products.
authors.affiliation: Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, People's Republic of China.
authors.forename: Li-Bin
authors.initials: LB
authors.lastname: Liu
authors.forename: Zhi-Xia
authors.initials: ZX
authors.lastname: Zheng
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D004809:Ephedrine / Q000031:analogs & derivatives / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D004364:Pharmaceutical Preparations / Q000737:chemistry; D010665:Phenylpropanolamine / Q000302:isolation & purification; D013237:Stereoisomerism; D013696:Temperature; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D002021:Buffers; D004364:Pharmaceutical Preparations; D047392:beta-Cyclodextrins; D010665:Phenylpropanolamine; C038119:heptakis(2,6-O-dimethyl)beta-cyclodextrin; C041707:N-methylephedrine; D004809:Ephedrine