Abstract: With the aid of combining 1,8-naphthalene with benthiazole through bis-triazene group, a new fluorescent reagent 1,8-bis(2-benthiazolydiazoamino)naphthalene(BBTANP) was synthesized and confirmed by means of elemental analysis, 1H NMR and infrared spectra. A chelate complex was formed by the reaction between BBTANP and Cu(Ⅱ) in a weak basic medium, which resulted in fluorescence enhancement. The possible response mechanism of BBTANP to Cu(Ⅱ) was discussed. The reaction showed a high selectivity and a high sensitivity for Cu(Ⅱ). A new spectrofluorimetric method for the determination of trace Cu(Ⅱ) with this reagent was developed. The excitation and emission wavelengths of BBTANP/Cu(Ⅱ) system were 362 and 459 nm in a basic medium, respectively. Under the optimal conditions, a linear response to copper was obtained in the concentration range from 8.0×10^-7 to 1.0×10^-5 mol/L, and the detection limit was 1.3×10^-7 mol/L. The method is selective, sensitive and simple. It has been used to determine trace copper in lake water with satisfactory results.

Key words: 1,8-Bis(2-benthiazolydiazoamino)naphthalene, Fluorescence enhancement, Detemination of copper