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
Europium can form a stable chelate with pyridine-2,4,6-tricarboxylic acid (PTA) with a ratio of 1:1 in aqueous. The system, having the maximum excitation and emission wavelengths at 311.0 nm and 616.3 nm, separately, ...Europium can form a stable chelate with pyridine-2,4,6-tricarboxylic acid (PTA) with a ratio of 1:1 in aqueous. The system, having the maximum excitation and emission wavelengths at 311.0 nm and 616.3 nm, separately, shows a constant fluorescence intensity in the pH range of 11.0-12.0. The method has high selectivity and sensitivity as well as low effect from foreign ions. The optimum determinate conditions were obtained. The fluorescence intensity is a linear function of Eu3+, concentration in the range of 0.0029-1.5200 mu g center dot mL(-1) and the limit of detection is 2.90 ng center dot 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
A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process...A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process is omitted.The detection limit is about 10^(10) mol/L antigen.The relative standard deviation of immunoassay is less than 10%.The recoveries of human serum albumin and estradiol protein conjugate are 96-105% and 111% respectively.展开更多
A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process ...A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process is unnecessary.The recovery of HSA and albumin in urine is 107% and 95% respectively.The standard deviation is tess than 10%.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.
基金This project was financially supported by the Natural Science Foundation of Gansu Province, China (ZR-97-21).
文摘Europium can form a stable chelate with pyridine-2,4,6-tricarboxylic acid (PTA) with a ratio of 1:1 in aqueous. The system, having the maximum excitation and emission wavelengths at 311.0 nm and 616.3 nm, separately, shows a constant fluorescence intensity in the pH range of 11.0-12.0. The method has high selectivity and sensitivity as well as low effect from foreign ions. The optimum determinate conditions were obtained. The fluorescence intensity is a linear function of Eu3+, concentration in the range of 0.0029-1.5200 mu g center dot mL(-1) and the limit of detection is 2.90 ng center dot 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.
基金This work was supported by National Natural Science Foundation of China.
文摘A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process is omitted.The detection limit is about 10^(10) mol/L antigen.The relative standard deviation of immunoassay is less than 10%.The recoveries of human serum albumin and estradiol protein conjugate are 96-105% and 111% respectively.
基金supported by National Commission of Natural Science Foundation of China.
文摘A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process is unnecessary.The recovery of HSA and albumin in urine is 107% and 95% respectively.The standard deviation is tess than 10%.
