Study On Spectral Behavior Of The Interaction Between Fluorone Reagent And Metallic Ions (Pb～(2+),Pd～(2+),Ga～(3+),Ag～+) And Its Analytical Application

In this paper, the structure, dissociation equilibrium of tri-hydroxyl fluorone reagents and the application to the spectrophotometry and fluorescence spectrometry have been reported in detail. The definition, classes, microstructure, solubilization and sensitization of microemulsion as well as it's application to analytical chemistry are also summarized in the paper.On the basis of phenyl fluorone (PF) reagent, the developing reactions of series of tri-hgdroxyl fluorone reagents with different substituents (PF, DBH-PF, TM-PF, o-CPF, o-NPF) and metallic ions (Pb2+ Pd2+) have been researched in the presence of microemulsion media. The effects of different conditions such as media, pH value, amount of microemulsion etc on the color reactions have been studied in the paper. The results of experiment show that lead( II) reacts with PF to form a stable 1:3 complex at pH 9.5 and it's apparent molar absorptivity is 6.04 X 104 L moL"1 cm'1 at 572 nm. Lead( II) reacts with o-Chlorophenylfluorone (o-CPF) to form a stable 1:3 complex at pH 9.20 and it's apparent molar absorptivity is 5.53 X 104 L moL"1 cm"1 at 575nm. Pd2+ reacts with o-Chlorophenyl fluorone in the presence of CTMAB microemulsion systems to form a stable 1:2 complex and the maximum absorption wavelength is 582 nm and the apparent molar absorptivity is 7.34 X 104 L moL"1 cm"1, Pd2+ reacts with o-Chlorophenylfluorone (o-CPF) in CTMAB microemulsion to form a stable complex and the apparent molar absorptivity is 8.87X 104L mol/'cm"1 The method is used to determine trace amount of Pb2+ and Pd2+ in samples with satisfactory results.The new methods have been developed for the determination of micro-amount of Ga3+ and Ag+, based on the fluorescence quenching effect of Ga3+-DBH-PF and Ag+-o-phen-TM-PF system. The effects of different conditions such as wavelength, media and acidity of system etc on the reactions have been researched. The results of experiments are as follows: Gallium(III) reacts with DBH-PF to form a stable 1:3 complex at pH 4.08 - 5.59. The calibration graph is of good linearity in the range of 0 - 0.1 g mL-1 of Ga3+ with a detection limit of 0.0034 g mL-1; Ag+reacts with TM-PF to form a stable complex at pH 6.78-7.57 and the Beer's law is obeyed in the range of 0 - 1.0 fig-mL'1 for Ag+ The detection limit achieved is down to 0.0069 g mL-1. It can be used to determine Ga3+ and Ag+ in samples successfully.The influences on the abilities of the color reaction (the structures of fluorone reagents and the solubilization and sensitization of microemulsion ) have been validated. The structures of fluorone reagents have important influence on the color reaction abilities. Electron-donating substituting groups make protons of reactive groups dissociate easily, and increase complex ability of fluorone reagent with metallic acid. The microemulsion media have more excellent solubilization and sensitization effect on the color reactions than other media. In the microemulsion media, consurfactants, which locate on the surface of micelle reagent. Oil, which lies in the core of micelle,...