Fluorescence characteristics of Schiff bases derived from aminopyridines and salicylaldehyde were studied and possibilities of their analytical application were discussed. It is shown that these compounds can be used for spectrofluorimetric monitoring of small pH changes as well as for sensitive metal ion determinations. As an illustration of metal ion determination, a spectrofluorimetric procedure for analysis of Cu2+ is presented. Determination of Cu2+ was based on the quenching effect of Cu2+ on the fluorescence of N,N\u27-bis(salicylidene)-2,3-pyridinediamine in dioxan/water 1/1 (volume fraction of dioxan, φ = 50%). Under optimal conditions (pH = 8.9, λex = 340 nm, λem = 385 nm, cligand = 1.0 x 10-5 M), the linearity range of the calibration curve was 30-350 μg L-1 Cu2+. The procedure is fast, simple and reproducible. It is characterized by high sensitivity and satisfactory selectivity. An additional advantage of Schiff bases derived from aminopyridines as analytical reagents lies in the simplicity of preparation procedures, enabling improvement of the determination methods not only by optimization of experimental conditions, but also by designing suitable struetural characteristics of the reagent
