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Study Of Thiacalixarene Separation/Preconcentration And Determination Of Trace Noble Metal And Heavy Metal Ions With Flame Atomic Absorption Spectrometry

Posted on:2008-07-05Degree:MasterType:Thesis
Country:ChinaCandidate:R H HuangFull Text:PDF
GTID:2121360218457943Subject:Analytical Chemistry
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On the basis of numerous references, thiacalixarene was chosen to be studied by its or its derivative's characteristics and the existing state of being studied at home and abroad. P-tert-butyl-thiacalixarene 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 metal ions. The separation and concentration behavior of some noble metal and heavy metal ions had been studied respectively, and then new methods for analysis and determination by FAAS of trace noble metal and heavy metal ions have been established. The methods were simple / accrual and high selection. At the same time, the field of thiacalixarene applied was enlarged, and a new train of thought was advanced for using"the third macrocycle host molecules"greenly.This paper consists of four chapters:In chapter one, the applying of separation, concentration metal ions with the means of chemistry were simply introduced in analysis of trace noble metal and heavy metal ions. And this review deals with history, property, application of calixarene and its derivative used a new type of adsorbent material in separation analysis. At the same time, for a novel kind of moleculereceptors—the thiacalixarene derivative, the recent progress in receptorchemistry and applications in the analytical chemistry were summarized.In chapter two, the thiacalixarene was synthesized .The 1HNMR spectra, FT-IR, Ultimate analysis and thermal analysis were quite similar to those of the literature, and loaded on chromatograph 301 to get a new type of adsorbent—resin loaded thiacalixarene. A new method for the determination of trace Ag with chromatograph 301 resin loaded thiacalixarene by flame atomic absorption spectrometry was established. The optimal working conditions and the adsorbing principle for the determination were studied. It was found that the studied silver could be adsorbed and recovered quantitatively on chromatograph 301 resin loaded thiacalixarene when the silver solution at pH=10 was shaken for 10 min and then deposited for 10 min at temperature 23±2℃.And 0.15 mol·L-1 HCl-0.15 mol·L-1 thiourea was sufficient for complete elution. The detection limit (3σ,n = 11) of the method was 0.170μg / L. The linear range was 0.006~3.000μg/mL and relative standard deviation was 1.5 % (n=7, c=0.180μg/mL). The recoveries of silver were 99.9~105.0%. The proposed methods were successfully applied to the separation, preconcentration and trace determination of Ag from scoria of zincum and the environmental water sample.In chapter three, the thiacalixarene was loaded on big-aperture D101 resin. The resin micro-column separation and preconcentration system was established for determination of trace gold by flame atomic absorption spectrometry. The optimal working conditions and the adsorbing principle of gold for the determination were studied. The detection limit (3σ,n = 11) of the method was 0.23ng/mL. The linear range was 0.01~1.0μg/mL and relative standard deviation was 2.1 % (n=5,c=0.20μg/mL). The recoveries of gold were 98.4~103.3%. The proposed method has been applied for the determination of trace Au in scoria sample with satisfactory results.In the chapter four, the separation and concentration behavior of the deleterious heavy metal ionsCd2+ has been studied. The optimal working conditions and sorption equilibrium were detailedly studied. It was found that could be adsorbed quantitatively silica gel on loaded thiacalixarene when the cadmium solution at pH=8.0 was shaken for 8 min at temperature 25℃. On condition of low concentration, the process of cadmium adsorbed by silica gel on loaded thiacalixarene could be described with Langumuir model and Freundlich model. The maximal saturation adsorption capacity by calculating was 11.76mg/g. The cadmium was sufficient for complete elution by 7mL 0.1mol/L HCl. The detection limit (3σ,n = 11) of the method was 0. 3 ng/mL. The linear range was 0.001~0.180μg/mL and relative standard deviation was 2.03 % (n=7,c=0.1μg /mL).
Keywords/Search Tags:Thiacalixarene, Separation and Preconcentration, FAAS, Noble Metal and Heavy Metal Ions
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