Synthesis and characterization of a novel cross-linking complex of beta-cyclodextrin-o-vanillin benzoylhydrazone and its selective spectrofluorimetric determination of trace amounts of zinc.

A novel host inclusion complex of beta-cyclodextrin-o-vanillin benzoylhydrazone (beta-CDP-OVBH) was prepared and characterized by IR and 1H-NMR spectra. A highly selective and sensitive fluorescent determination of trace amounts of zinc was proposed based on the reaction between Zn(2+) and beta-CDP-OVBH in sodium hydroxide-ammonium acetate buffer medium of pH 8.3. The molar ratio of beta-CDP-OVBH to Zn(2+) was 1:1. The maximum excitation and emission wavelengths were 396 and 486 nm, respectively. The linear range of this method was 2.5-500 microg l(-1) with a detection limit of 0.60 microg l(-1). The effect of interferences in the determination of zinc was investigated, the results showed that the host reagent had a quite high identifying capacity on Zn(2+). This method was successfully applied to the determination of trace amounts of Zn(2+) in tea and human hairs.