A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphe...A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine（DBHPF） when they are in the molar ratio of 1：2 in the nonionic microemulsion medium.Under optimum conditions,the system,having the maximum excitation and emission wavelengths at 468 nm and 532 nm,respectively,shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ions.Furthermore,this fluorescence intensity is a linear function of Pt（IV） concentration in the range of 0.002-1.00 μg·mL^-1 and the limit of detection is 2.90 ng·mL^-1.展开更多
The fluorescence intensity of the europium(Ⅲ) tetracycline (TC)complex can be greatly increased by TOPO,TBP,TTA and surfactans,among which TOPO showed the greatest enhancement.The formation of ternary complex was pr...The fluorescence intensity of the europium(Ⅲ) tetracycline (TC)complex can be greatly increased by TOPO,TBP,TTA and surfactans,among which TOPO showed the greatest enhancement.The formation of ternary complex was proposed to be responsible for the fluorescence enhancement .The Eu(Ⅲ) TOPO TC system can be applied to the determination of trace amounts of tetracycline in urinous sample; the maximum fluorescence intensity was obtained in the pH range of 8.2￣9.5 with excitation and emission wavelengths at 396 nm and 616 nm,respectively.The linear range for tetracycline is 6.0×10 -9 5.0×10 -7 mol·L -1 .The detection limit is 2.0×10 -9 mol·L -1 (SNR=3). Experimental conditions and the mechanism of the enhancement effect are discussed.展开更多
文摘A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine（DBHPF） when they are in the molar ratio of 1：2 in the nonionic microemulsion medium.Under optimum conditions,the system,having the maximum excitation and emission wavelengths at 468 nm and 532 nm,respectively,shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ions.Furthermore,this fluorescence intensity is a linear function of Pt（IV） concentration in the range of 0.002-1.00 μg·mL^-1 and the limit of detection is 2.90 ng·mL^-1.
文摘The fluorescence intensity of the europium(Ⅲ) tetracycline (TC)complex can be greatly increased by TOPO,TBP,TTA and surfactans,among which TOPO showed the greatest enhancement.The formation of ternary complex was proposed to be responsible for the fluorescence enhancement .The Eu(Ⅲ) TOPO TC system can be applied to the determination of trace amounts of tetracycline in urinous sample; the maximum fluorescence intensity was obtained in the pH range of 8.2￣9.5 with excitation and emission wavelengths at 396 nm and 616 nm,respectively.The linear range for tetracycline is 6.0×10 -9 5.0×10 -7 mol·L -1 .The detection limit is 2.0×10 -9 mol·L -1 (SNR=3). Experimental conditions and the mechanism of the enhancement effect are discussed.
