Studies And Applications Of The Separation And Preconcentration Of Trace Precious Metals By Nano-alumina And Determination With AAS

In analytical sciences, separation/pre-concentration is usually indispensable to improve the sensitivity and selectivity of the analytical method. Solid phase extraction (SPE) is a sample preparation technique that originated in the 1970s and developed from the late of the 1980s, and has the advantage of high pre-concentration factor, simplicity of operation, less pollution to the environment, easy automation, and can be applied to the different samples. Nanometer-sized material as a novel function material, which has come into the world in 1980s, has made a great progress in recent years. The regime of nanoparticle is from 1 to 100 nm, which falls between the classic fields of chemistry and solid-state physics. The smaller the diameters are, the more atoms are on their surface, and the bigger the surface area is. The surface atoms in nanometer materials are unsaturated and can bind with other atoms. All these characteristics make nanometer materials be an ideal solid phase adsorption materials in modern analytical chemistry.The atomic adsorption spectrometry (AAS), which has the merits of low cost and detection limit, good precision and accuracy, and wide linear range, has been widely applied in trace analysis. By coupling SPE with AAS, the analytical performance of the analytical method, such as sensitivity, detection limit and antijamming capability, could be efficiently improved. At the same time, it also extends the application field of SPE.In this dissertation, the self-made nano-alumina was applied in the field of SPE, and the adsorption characteristics and mechanism of some precious element ions on nano-alumina material was systematically studied with FAAS. A novel method was developed for determination of trace precious elements, which combined AAS with separation/pre-concentration by nano-alumina material with high stability and relative high selectivity, long life and pollution-free. The main contents were described as follows:1. The samples of nano-alumina of uniform partical diameter were prepared by improved Sol-Gel method. Then, the product was to be determined by IR and TEM. It was found that the product is nano-alumina. Moreover, there is little...