Synthesis Of Novel Solid Phase Extractant Based On Fibre And Silica Gel And Their Application For Solid Phase Extraction Of Metal Ions

The dissertation is composed of the following four parts:1 .IntroductionThis part includes the concept and characters of solid phase extraction and systematically provides a comprehensive review of chelating fibre and modified silica gel as solid phase extractants and their application on preconcentration and separation of trace metal ions in recent years.2. The Research of Analytical method with high accuracy and precision of Au in copper raw materialsThe Research which was one of the scientific and technological development projects of Jinchuan Group Limited Corporation was presided over by my supervisor, professor Xijun Chang. On the basis of our former work, PAAAT-ADAT chelating fiber was synthesized simply and rapidly and used for pre-concentration and separation of trace Au(III) from solution samples. The acidity, rate, desorbed conditions, reuse, adsorption capacity, rate constant, interference on the adsorption of Au(III) and combination mechanism on this chelating fiber were investigated in detail. The precision and accuracy of the proposed method were achieved by analysis of copper raw materials with satisfactory.3. Silica gel modified with diaminothiourea as selective solid-phase extractant for determination of Hg(II) in biological and natural water samplesDiaminothiourea(DATU)-modified silica gel was obtained by a surface modifying technique on silica gel for preconcentration of trace Hg(II) prior to the measurement by cold vapor atomic absorption spectrometry (CVAAS). The separation / preconcentration conditions of the analyte, which included the effects of the pH, the sample flow rate, the elution condition, shaking time and the interfering ions on the recovery of the analyte were investigated. At pH 2, the adsorption capacity of modified silica gel for Hg(II) was found to be 36.3 mg g^-1. According to the definition of IUPAC, the detection limits (3σ) of this method for Hg(II) was 0.28 ng mL^-1. The proposed method achieved satisfying results when it was applied to the determination of trace Hg(II) in biological and natural water samples. 4. Silica gel modified with 1-nitroso-2-naphthol-3,6-disulfonate sodium(NNDS) as selective solid-phase extractant for determination of Cr(III) in natural water samples1-nitroso-2-naphthol-3,6-disulfonate sodium(NNDS)-modified silica gel was obtained by a surface modifying technique on silica gel for preconcentration of trace Cr(III) prior to the measurement by inductively coupled plasma optical emission spectrometry(ICP-OES). The separation / preconcentration conditions of Cr(III), which included the effects of the pH, the sample flow rate and volume, the elution condition, detection limit, precision and the interfering ions on the recovery of Cr(III) were investigated in detail. The accuracy of the proposed method was checked by analyzing standard reference material with satisfactory results. In addition, some natural water samples were analyzed using the standard addition method, the recoveries of trace Cr(III) added to these samples are 95-101 %.