title: Simultaneous kinetic determination of levodopa and carbidopa by H-point standard addition method.
abstract: The kinetic H-point standard addition method (HPSAM) was applied to the simultaneous determination of levodopa and carbidopa. The method was based on the difference in the rate of oxidation of these compounds with Cu(II)-neocuproine system and formation of Cu(I)-neocuproine complex at pH 5.5. The absorbance of the Cu(I)-neocuproine complex was monitored at 453 nm. Experimental conditions such as pH, reagent concentrations, ionic strength and temperature were optimized. Simultaneous determination of levodopa and carbidopa was performed in the range of 0.8-4 and 0.2-1.5 microg ml(-1), respectively. The proposed method was applied to the simultaneous determination of levodopa and carbidopa in pharmaceutical samples, and satisfactory results were obtained.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 71454, Iran. safavi@chem.susc.ac.ir
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Safavi
authors.forename: Maryam
authors.initials: M
authors.lastname: Tohidi
mesh_terms: D000978:Antiparkinson Agents / Q000032:analysis*; D002230:Carbidopa / Q000032:analysis*; D000431:Ethanol / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007980:Levodopa / Q000032:analysis*; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000032:analysis*; D010618:Phenanthrolines / Q000737:chemistry; D012680:Sensitivity and Specificity; D012995:Solubility; D013053:Spectrophotometry / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry; D013607:Tablets / Q000032:analysis; D013696:Temperature
chemical_list: D000978:Antiparkinson Agents; D005079:Excipients; D004364:Pharmaceutical Preparations; D010618:Phenanthrolines; D013501:Surface-Active Agents; D013607:Tablets; D000431:Ethanol; D007980:Levodopa; C002701:neocuproine; D002230:Carbidopa