Studies And Applications Of The Separation And Preconcentration Of Trace Harmful Elements Hg,Cd,Cr With Mesoporous Molecule-sieve And Determination By Atomic Spectrometry

On the basis of numerous references, through in-depth and systemic studied, mesoporous molecule-sieve was chosen to be studied because its aperture and shape can be controlled or its derivative's characteristics and the existing state of being studied at home and abroad. Mesoporous molecule-sieve firstly has been synthesized and then impregnated, loaded or bonded on the carrier to prepare a new type of adsorbent material which was applied to separate/enrich harmful metal ions. The separation and concentration behavior of Hg,Cd,Cr ions had been studied respectively, and then new methods for analysis and determination by FAAS of trace heavy harmful metal ions have been established. The methods were simple / accurate and highly selection. At the same time, the field of mesoporous molecule-sieve applied was enlarged.The major contents include four parts, there are described as follows:1. The methods of separation/preconcentration and kinds of adsorption materials in atomic adsorption spectrometry detemination were reviewed. The characteristics and application in separation/preconcentration of new adsorption material- mesoporous molecule-sieve were introduced in detail.2. A new functiontalized organic-inorganic mesoporous material has been studied on preconcentration and determination of trace mercury. Determination of trace mercury by atomic fluorescence spectrometry (AFS) after perconcentration on supported this material was elutioned with thick HCl. The linear range was 0.005~5 ng/mL. The detection limit was 1.89×10-9 g/L(3σ). The RSD was 2.69﹪(n=11 , c=0.5 ng/mL). The recoveries of mercury were 95.3~104.5﹪. The method has been applied for determination of trace mercury in water samples with satisfactory results.3. A new method of determination of trace cadmium with mesoporous molecule-sieve P123-SH material by flame atomic absorption spectrometry (FAAS) was reported. The linear range was 0.0005～0.1mg/L. The detection limit was 0.12μg/L (3σ,n=11). The recoveries of cadmium were 102%~104%.The RSD was 2.13%(n=7, c=0.05 mg/L). The method has been applied for determination of trace cadmium in water samples with satisfactory results.4. Mesoporous molecule-sieve SBA-15(NH2) was synthesized through grafted mothed, use SBA-15 and 3-aminopropyltriethoxysilane as reagent, SBA-15(NH2) was synthesized at strict conditions in our laboratory. A PTFE micro column packed with SBA-15(NH2) was used in FI (flow injection)-FAAS (flame atomic adsorption spectrometry) system for the determination trace Cr forms in environment sample. The linear range was 0.0002~2.0μg/mL.The detection limit was 0.10 ng/mL. The linear equation was A=0.1198C+0.0545(C:μg/mL,r=0.9978). The RSD was 2.8%. The recoveries of Cr(Ⅲ) was 99.0%~104.0%. The method has been applied for the determination of trace Cr forms in environmental and biological samples with satisfactory results.