Application of the first derivative spectra method for investigation of the complexation of some aza-15-crown-5-containing chromoionophores with Sr(2+).

An approach for quantitative spectrophotometric analysis of binary mixtures based on first derivative spectra is developed. The proposed method is used for investigation of the complex formation of some aza-15-crown-5-containing ligands with Sr(2+), where the stability constant is low and the absorption spectrum of the complex cannot be obtained directly. The described general approach can be applied for quantitative analysis of any other two-component mixture where the absorption spectra of the components cannot be obtained experimentally.