title: Analysis of optical purity and impurity of synthetic D-phenylalanine products using sulfated beta-cyclodextrin as chiral selector by reversed-polarity capillary electrophoresis.
abstract: A new capillary electrophoresis (CE) method has been achieved for simultaneous separation and quantification of phenylalanine, N-acetylphenylalanine enantiomers, and prochiral N-acetylaminocinnamic acid, possibly co-existent in reaction systems or synthesized products of D-phenylalanine. The separation was carried out in an uncoated capillary under reversed-electrophoretic mode. Among the diverse charged cyclodextrins (CDs) examined, highly sulfated (HS)-beta-CD as the chiral selector exhibited the best enantioselectivity. The complete separation of the analytes was obtained under the optimum conditions of pH 2.5, 35 mM Tris buffer containing 4% HS-beta-CD, applied voltage -15 kV, and capillary temperature 25 degrees C. Furthermore, the proposed method was applied to the determination of optical purity and trace impurities in three batches of the asymmetric synthetic samples of D-phenylalanine, and satisfactory results were obtained. The determination recoveries of the samples were in the range of 97.8-103.8%, and precisions fell within 2.3-5.0% (RSD). The results demonstrate that this CE method is a useful, simple technique and is applicable to purity assays of D-phenylalanine.
authors.affiliation: Department of Chemistry, Fourth Military Medical University, Xi'an 710032, China. yanzhao@fmmu.edu.cn
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xing-Bin
authors.initials: XB
authors.lastname: Yang
authors.forename: Ru
authors.initials: R
authors.lastname: Jiang
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Sun
authors.forename: Xiao-Ye
authors.initials: XY
authors.lastname: Li
authors.forename: Wen-Min
authors.initials: WM
authors.lastname: Liu
authors.forename: Sheng-Yong
authors.initials: SY
authors.lastname: Zhang
mesh_terms: D002384:Catalysis; D003505:Cyclodextrins / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D010649:Phenylalanine / Q000737:chemistry*; D012044:Regression Analysis; D012984:Software; D013237:Stereoisomerism; D013696:Temperature; D013997:Time Factors; D014325:Tromethamine / Q000494:pharmacology; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D014325:Tromethamine; D010649:Phenylalanine; C031215:betadex