Analysis Of Heavy Metallic Ions In Environmental Water Samples

In this paper, the microstructure, preparation and properties of microemulsion have been reported in detail, as well as its application to analytical chemistry in the world. On the basis of phenyl fluorone (PF) reagent, the developing reactions of series of tri-hydroxyl fluorone reagents with different substituents and metallic ions (Pb2+, Cd2+) have also been researched in the presence of microemulsion media. According to the calculation of fluorone reagents in quantum chemistry, their dissociation equilibrium forms in different acidity have been studied. The possible complex structures between fluorone reagents and metallic ions are presented in the paper. For the purpose of verifying solubilization and sensitization of microemulsion, the distribution coefficients (KD) of PF reagent between phases of micelles, microemulsion and water have been determined.In terms of experimental results, the structures of fluorone reagents have important influence on their developing properties. Electron-donating groups make protons of reactive groups dissociate hardly, and reduce complex ability of fluorone reagents with metallic ions. However, electron-withdrawing groups that have conjugative effect in molecule can increase complex ability, sensitivity and selectivity of fluorone reagents.From the experiment, it is clear that microemulsion media have more excellent solubilization and sensitization than micelle and water media. In the microemulsion media, consurfactants (straight chain alcohol), which locate on the surface of micelle, can effectively improve polarity of micelle surface and increase adsorption amounts of developer; oils (alkane), which lie in the kernel of micelle, can directly expand the bulk, surface and barrier space of micelle. Hence, developer will be easily caught at the places of surface and barrier of micelle. The determination results of KD have indicated that microemulsion media have more high solubilization and enrichment for developer than micelle media. Therefore, microemulsion media have excellent sensitization in the developing system.According to the experiment, the proposed methods based on the developing conditions of DBH-PF-metallic ion have successfully applied to determination of metallic ions in environmental samples.