Chromaticity characteristics of two-and three-component vanadium(IV,V) 4-(2-pyridylazo)resorcinolates

The optimum conditions of the complexation of vanadium(IV, V) with 4-(2-pyridylazo)resorcinol without and with hydrogen peroxide or hydroxylamine were found, and chemical analytical characteristics of the complexes were determined. Molar coefficients of chromaticity functions were calculated. It was demonstrated that they depend on the oxidation number of vanadium in the complex; this fact confirms the expected difference in the oxidation number of the central ion, which was found in the determination of optical characteristics. Coefficients of equations and linearity boundaries of the calibration dependences of optical and chromaticity characteristics of the complexes on the concentration of the central ion were calculated. The higher sensitivity of chromaticity measurements in comparison with spectrophotometry was demonstrated.