title: Simultaneous determination of thyroxine and triiodothyronine in pharmaceutical formulations using capillary electrophoresis with amperometric detection.
abstract: A simple, reliable and repeatable method, based on CE with amperometric detection has been developed for the simultaneous separation and determination of thyroxine (T(4)) and 3,3',5-triiodothyronine (T(3)). A carbon disk electrode was used as working electrode in this system and exhibited a good response at 1.05 V (versus Hg/Hg(2)Cl(2), 3 mol/L KCl) for two analytes. The CE separations were investigated in detail. At 21 kV of applied voltage, the two compounds were separated within 11 min in 0.05 mol/L Na(2)B(4)O(7)-NaOH buffer (pH 11.3). And the detection limits were as low as 1.0x10(-7) mol/L for T(4) and 8.5x10(-8) mol/L for T(3) (S/N=3), respectively. The proposed method was applied to analyze T(4) and T(3) in pharmaceutical formulations, and the results were satisfactory.
authors.affiliation: Department of Environmental Science, East China Normal University, Shanghai, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Zhao
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Guoyue
authors.initials: G
authors.lastname: Shi
authors.forename: Tianshu
authors.initials: T
authors.lastname: Zhou
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004563:Electrochemistry; D019075:Electrophoresis, Capillary; D004364:Pharmaceutical Preparations / Q000032:analysis*; D013974:Thyroxine / Q000032:analysis*; D014284:Triiodothyronine / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D014284:Triiodothyronine; D013974:Thyroxine