A new quaternary photoluminescence enhancement system of Eu-N-(o-vanillin)-1,8-diaminonaphthalene-1,10-phenanthroline-Zn and its application in determining trace amounts of europium and zinc.

A new sensitive quaternary photoluminescence enhancement system has been successfully developed to determine trace amounts of Eu(3+) and Zn(2+). The photoluminescence intensity of Eu - N-(o-vanilin)-1,8-diaminonaphthalene systems was greatly increased by the addition of specific concentrations of 1, 10-phenanthroline and Zn(2+). The excitation and emission wavelengths were 274 and 617 nm, respectively. Under optimal system conditions, the photoluminescence intensity showed a linear response toward Eu(3+) in the range of 5.0 × 10(-6)  ~ 2.0 × 10(-5)  M with a limit of detection (= 2.2 × 10(-9)  M) and the photoluminescence intensity of the system decreased linearly by increasing the Zn(2+) concentration in the range of 5.0 × 10(-8)  ~ 1.0 × 10(-6)  M with a limit of detection (= 8.8 × 10(-11)  M). This system was successfully applied for the determination of trace amounts of Eu(3+) in a high purity La2O3 matrix and in the synthetic rare earth oxide mixture, and of Zn(2+) in a high purity Mg(NO3)2 · 6H2O matrix and in synthetic coexisting ionic matrixes. The energy transfer mechanism, photoluminescence enhancement of the system and interference of other lanthanide ions and common coexisting ions were also studied in detail.