Successive ratio-derivative spectra as a new spectrophotometric method for the analysis of ternary mixtures.

A new spectrophotometric method was developed for the simultaneous determination of ternary mixtures, without prior separation steps. This method is called the successive derivative ratio spectra. The method is based on the successive derivative of ratio spectra in two steps. The mathematical explanation of the procedure is illustrated. In order to evaluate the applicability of the method a model data as well as an experimental data were tested. The results from experimental data relating to the simultaneous spectrophotometric determination of Zn(II), Co(II) and Ni(II) based on their complexes with 1-(2-pyridylazo)2-naphthol in micellar media were presented as real model for resolution of the ternary systems. The method was compared with partial least squares (PLS) method.