Enhanced Luminescence of Europium by Gadolinium and Its Application

Abstract

The fluorescence enhancement of the Eu-dibenzoylmethane(DBM)- cetylpyridinium-chloride (CPC) system was studied. The fluorescence intensity of the system can be greatly increased by Gd³⁺ in the presence of triethanolamine(TEA). The optimum conditions for enhanced fluorescence of the Eu-Gd-DBM-CPC system were examined. It was a linear function of the Eu³⁺ concentration in the range of 1.0×10^?10～1.0×10^?8 mol dm^?3 under the optimized conditions. The detection limit was 2.6 × 10¹¹ mol dm^?3 in an aqueous solution at pH=7.5～9.5.

The Eu-Gd-DBM-CPC system was applied to the determination of europium in rare earth oxides with satisfactory results. The mechanism of enhanced fluorescence was discussed.