COMPUTER METHOD FOR THE SIMULTANEOUS KINETIC DETERMINATION OF COMPOUNDS IN MIXTURES BASED ON THE USE OF DIODE-ARRAY SPECTROPHOTOMETRY

A computer method for the treatment of kinetic data provided by a diode-array spectrophotometer was developed. The method relies on a non-linear regression procedure for estimating the rate constants and concentrations of mixture components. The underlying principle of this method is fitting the absorption matrix obtained as a function of time and wavelength to a theoretical kinetic equation. This allows the resolution of mixtures of compounds with similar rate constants in a simultaneous fashion provided that they or their reaction products feature appreciable spectral differences from one another. The proposed method was applied to the resolution of Co(II) (0.1-1.0 mug ml-1)-Ni(II) (0.5-5.0 mug ml-1) mixtures based on displacement from their the EGTA complexes by 4-(2'-pyridylazo)resorcinol.