title: A spectroscopic study on applicability of spectral analysis for simultaneous quantification of l-dopa, benserazide and ascorbic acid in batch and flow systems.
abstract: The usefulness of derivative spectrophotometry for simultaneous assay of l-dopa, benserazide and ascorbic acid in pharmaceuticals was studied. The parameters of derivatisation depends on composition of solution in which particular compound was determined. For quantification of l-dopa in mixtures with benserazide or ascorbic acid the first derivative was used. Its determination in ternary mixture (l-dopa+benserazide+ascorbic acid) is possible by third derivative spectra. Benserazide was assayed in presence of l-dopa using first derivative while in ternary mixture by third derivative. Direct determination of ascorbic acid is possible applying first derivative only in presence of l-dopa. The elaborated derivative spectrophotometric methods were used for assaying of l-dopa and benserazide in their commercial form "Madopar". The proposed spectrophotometric derivative method of simultaneous determination of l-dopa and benserazide was combined with FIA technique.
authors.affiliation: Institute of Chemistry, University of Bialystok, ul. Hurtowa 1, 15-399 Białystok, Poland. joasia@uwb.edu.pl
authors.forename: Joanna
authors.initials: J
authors.lastname: Karpińska
authors.forename: Jerzy
authors.initials: J
authors.lastname: Smyk
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Wołyniec
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis*; D001545:Benserazide / Q000032:analysis*; D002138:Calibration; D007980:Levodopa / Q000032:analysis*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation / Q000379:methods
chemical_list: D007980:Levodopa; D001545:Benserazide; D001205:Ascorbic Acid