A spectroscopic study on applicability of spectral analysis for simultaneous quantification of L-dopa, benserazide and ascorbic acid in batch and flow systems

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. (c) 2004 Elsevier B.V. All rights reserved.