Synthesis and characterization of a novel cross-linking complex of beta-cyclodextrin-o-vanillin furfuralhydrazone and highly selective spectrofluorimetric determination of trace gallium

A novel host inclusion complex of cross-linking-polymeric-β-cyclodextrin-o-vanillin furfuralhydrazone (β-CDP-OVFH) was synthesized and characterized with IR and ¹H NMR spectra to confirm its structure. A highly selective and sensitive fluorescent determination of trace amounts of gallium was proposed based on the reaction between Ga³⁺ with β-CDP-OVFH in acetic acid-ammonium acetate buffer medium of pH 4.10. The maximum excitation and emission wavelengths were 392 and 499 nm, respectively. The linear range of this method was 1.5-330 ng ml⁻¹ with a detection limit of 0.44 ng ml⁻¹. The effect of interferences in the determination of gallium was investigated and the results showed that the same race elements such as Al³⁺ and In³⁺ did not interfere the determination of Ga³⁺ even when their concentration is 100 times of Ga³⁺, the host reagent had quite high capacity of identifying Ga³⁺. This method was successfully applied to the determination of trace amounts of Ga³⁺ in artificial and semiconductor samples.