Fluorimetry of Selected Elements and Substances in Complex and Micellar Media

dissertation

English

The collinear fluorescence spectra appear for complexes with 8-Hydroxyquinoline-5-sulphonic acid (QSA) with max 495 nm for Al, 504 nm for Ga and In in dependence on pH. The fluorescence is highly increased in the presence of submicellar concentration of cationic surfactants, especially Zephyramine. The stoichiometry of the components in the complexes is M:L = 1:1 - 1:3 in the absence of surfactant and M:L = 1:3 in the presence of cationic surfactant. The optimal concentration range for the determination of Al, Ga and In is 0.03 1 g.L-1, the detection limits 0.03-0.04 g.L-1 in the presence or absence of surfactant for normal and first derivative spectra. Fe3+, fluoride, phosphate and excess of nitrate and bromide interfere in the absence and presence of Zephyramine. The first derivative spectra for pH 3, 8 and 4 with max 460 nm for Al, 472 nm for Ga and 478 nm for In do not bring advantages. For the determination of Al, Ga, and In at pH 4, 3, and 8 in the presence of MES or tetraborate and Zephyramine is suitable. For the fast characteristics of mixtures of Aluminium, Gallium and Indium the fluorimetric evaluation in the form of complexes with 8-Hydroxyquinoline-5-sulphonic acid is described at selected pH. The highly collinear correlated fluorescent spectra and their first derivation were evaluated under various experimental conditions with the Multiple Linear Regression (MLR), Partial Least Squares (PLS) methods and Kalman filtering. When comparing the results, the PLS gives the least relative prediction errors under optimal conditions, 5.6-15.9 % for the concentration range of Al 0.025-0.2 g.cm-3, Ga 0.1-0.8 g.cm-3 and In 0.1-0.8 g.cm-3 in the mixture

8-hydroxyquinoline-5-sulphonic acid Aluminium, Gallium, Indium complexes Fluorescence Cationic surfactants The first derivative spectra Multivariate evaluation

VOJTA, Š.

24. 6. 2008