Surfactant Media, 8 - Hydroxyquinoline Spectroscopy Applied Research,

Spectroanalysis has been widely used in geology, chemical engineering, biology and medicament. Mining the conventional reagents for new application has now become the focal point of spectroanalysis for analysts in many countries. 8-hydroxyquinoline, as one of the effective organic reagents, has gotten wide use and investigation. Based on high sensitivity and solubilization of surfactants, the dissertation has studied the spectral analysis of 8-hydroxyquinoline in surfactant system, and the mechanism of sensitizing effect by surfactants were discussed. The major contents of this dissertation are described as follows:(1) Determination of aluminium(III) in water samples in a microemulsion system by spectro fluorimetryIn this article a simple and fast method of determination of trace aluminium(III) was proposed. 8-hydroxyquinoline has been extensively used as chelating reagent and it could react with metal ions and form complex with five-members ring structure. Aluminium(III) can be bound to 8-hydroxyquinoline and form the steady complex with fluorescence under certain experimental conditions. The sensitizing effect of cetyltrimetrylammonium bromide (CTAB) microemulsion media on the determination of aluminium(III) by spectrofluorimetry was developed. The main factors affecting the determination were investigated in detail. The results showed that 8-hydroxyquinoline(HQ) react with aluminium(III) forming a complex with fluorescence in the system of potassium acid phthalate-NaOH buffer solution at pH 6.0, the maximum excitation and emission wavelengths are at 380.0 nm and 502.6 nm, the sensitizing effect of CTAB microemulsion is higher than that of CTAB micelle. The fluorescence quantum yields of A1(III)-HQ complex (Φ_f ) in various media were determined respectively, and mechanism of sensitizing effect was discussed primarily.The proposed method has been applied to the determination of aluminium(III) in tap water and lake water samples with satisfactory results.(2) Sensitized Effect of microemulsion on chromium-8-hydroxyquinoline by derivative spectrophotometryIn recent years, more applications are applied of derivative spectrophotometry for its advantages, including high selectivity, sensitivity, accuracy and simplicity. The sensitizing and stabilizing effect of cetyltrimetrylammonium bromide (CTAB) microemulsion media on the determination of chromium using 8-hydroxyquinoline (8-HQ) by second derivative spectrophotometric was developed. In this work, the interference of magnesium in the determination of chromium was eliminated by the use of derivative spectrophotometry. Calibration graph based on second derivative measurement of chromium found that Lambert-Beer's law was obeyed when lead the concentration was in the range of 0~12ug/mL. The proposed method has been applied to the determination of chromium in standard plain steel sample with satisfactory results.(3) Determination of cobalt and nickel by dual-wavelength spectrophotometry with 8-hydroxyquinoline as chelating reagentThe development of dual-wavelength spectrophotometry was based on the traditional single-wavelength spectrophotometry. In recent years, more applications are applied of dual-wavelength spectrophotometry for its advantages, including high selectivity (It can select the obsorption of the analyte from absorbing and scattering of the interferences.), sensitivity, accuracy and simplicity in instrumentation. Cobalt and nickel are accompanying existences because their chemical properties are similar. The two ions must be separated by extraction with solvent before determined in conventional methods. In this article, the sensitizing effect of cetyltrimetrylammonium bromide (CTAB) microemulsion media on the determination of cobalt and nickel bydual-wavelength spectrophotometry was developed. The main factors affecting the direct determination were investigated in detail. The results showed that Beer's law was obeyed over the concentration range of 0~4.0 μg/mL of Co~2+ and 0~5.0 μg/mL Ni~2+. The proposed method has been applied to the determina...