A new synthesized fluorogenic reagent, 8-[(2-pyridine)methylideneamino] quinoline (PMAQ), was utilized for spectrofluorimetric determination of Cu(II) at trace levels. PMAQ, a good fluorogenic reagent, though insolubl...A new synthesized fluorogenic reagent, 8-[(2-pyridine)methylideneamino] quinoline (PMAQ), was utilized for spectrofluorimetric determination of Cu(II) at trace levels. PMAQ, a good fluorogenic reagent, though insoluble in water, but is soluble in ethanol and 20% ethanol-water. The excitation and the fluorescence wavelengths of PMAQ were 310 and 434 nm respectively. When the reagent was complexed with Cu(II), the fluorescence intensity decreased proportionally with the concentration of Cu(II) at pH 4.5 by a static quenching effect. The highest sensitivity to Cu2+ determination was shown to be at PMAQ concentration of 1.0 X 10(-5) mol.L-1. In order to enhance the quenching effect, the Cu(II)-PMAQ complex solution was kept at 22 degreesC for 20 min. Though the interferences by Co(II) and Fe(III) were very serious, they were however, completely eliminated by being masked with oxalate and ascorbate ions respectively. The linear dynamic range for Cu(II) determination was between 25-441 mug.L-1 with the detection limit of 18 mug.L-1 (RSD=3.7%, n=6). The proposed method was successfully applied to the determination of Cu(II) in real samples including human blood serum, commercial tea and wheat flour.展开更多
文摘A new synthesized fluorogenic reagent, 8-[(2-pyridine)methylideneamino] quinoline (PMAQ), was utilized for spectrofluorimetric determination of Cu(II) at trace levels. PMAQ, a good fluorogenic reagent, though insoluble in water, but is soluble in ethanol and 20% ethanol-water. The excitation and the fluorescence wavelengths of PMAQ were 310 and 434 nm respectively. When the reagent was complexed with Cu(II), the fluorescence intensity decreased proportionally with the concentration of Cu(II) at pH 4.5 by a static quenching effect. The highest sensitivity to Cu2+ determination was shown to be at PMAQ concentration of 1.0 X 10(-5) mol.L-1. In order to enhance the quenching effect, the Cu(II)-PMAQ complex solution was kept at 22 degreesC for 20 min. Though the interferences by Co(II) and Fe(III) were very serious, they were however, completely eliminated by being masked with oxalate and ascorbate ions respectively. The linear dynamic range for Cu(II) determination was between 25-441 mug.L-1 with the detection limit of 18 mug.L-1 (RSD=3.7%, n=6). The proposed method was successfully applied to the determination of Cu(II) in real samples including human blood serum, commercial tea and wheat flour.
