Study on the new fluorescence enhancement system of Zn–bis-(trimethylolaminomethane)-4-tert-butyl-disalicylicimine in the presence of β-cyclodextrin and its analytical application

A new bis-Schiff base ligand, bis-(trimethylolaminomethane)-4-tert-butyl-disalicylicimine (HL), was synthesized. The fluorescence intensity of HL–Zn2+ complex was increased by about 8-fold upon addition of β-cyclodextrin (β-CD). The spectrofluorimetric determination of trace amounts of Zn2+ based on the phenomenon was carried out. The excitation and emission wavelengths are 405 and 465 nm, respectively. Under optimal conditions, the fluorescence intensities vary linearly with the concentration of Zn2+ in the range 0–317 μg l−1 with a detection limit of 1.0 μg l−1. The interferences of some inorganic ions were described. The method is a selective, sensitive, rapid, and simple analytical procedure for the determination of Zn2+ in crops. The mechanism for the fluorescence enhancement was also discussed.