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(W/EH055) Silica modified with quaternary ammonium salt and Eriochrome cyanine R as solid-phase reagent for determination of aluminum in water. Zaporozhets, Olga1, Nadzhafova, Oksana1, Evreenko, Ludmila1, Sukhan, Vasilij, 1 ABSTRACT- Long chain quaternary ammonium salts can be easy adsorbed onto the surface of silica caused anion - exchange properties of the sorbent. Obtained modified sorbents were applied to preconcentration and determination of inorganic and organic anions. They can be also used as a perfect support for the anionic chromophorous organic reagents formed stable colored complexes with heavy metal ions. In the present work the sorption of Eriochrome cyanine R (ER) and its complexes onto the surface of silica modified with didecylaminoethyl-b-tridecylammonium iodide (DDATD) was studied using adsorption and diffuse reflectance spectroscopy technique. It was shown that maximum capacity level for ER onto DDATD-silica was 2.10-5 mol/g under optimal conditions. Reagent was not washed from the surface in the range of pH 3-6. Sorption of aluminum (III) onto DDATD-silica modified with ER was examined. Metal ion recovery for 95% within 10 min of the phases contact (10 ml of solution, 0.02 g of the sorbent). Obtained solid phase reagent was successfully applied to the determination of aluminum in natural water at its level > 8.0 ppb. Developed method showed satisfactory reproductively and accuracy. It was also demonstrated reversibility of the Al -ER complex formation on the surface. Thus DDATD-silica modified with ER was found to be a perspective selective material for optical sensor. Key words: Long chain quaternary ammonium salts , Eriochrome cyanine R , Adsorption, aluminium determination |
