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(W/EH054) Simple and fast spectroscopic and visual test determination of lead, zinc and mercury in natural objects at MAC level. Zaporozhets, Olga1, Tsukalo, Ludmila1, Keda, Tetjana1, 1 ABSTRACT- Attention has recently been focused on the development of fast and simple methods of Pb, Zn and Hg traces determination in environmental objects on the MAC level. Xylenol Orange (XO) and 1,5-Diphenylcarbazide (DFCd) are known to be one of the sensitive but not selective reagents for heavy metal ions spectrophotometric determination. The analytical reagents adsorbed on the surface of highly dispersed silica offer some distinct advantages over similar reagents in the solution, since they permit to combine the recovery with spectroscopic or visual test determination. As far as we know, no silica with DFCd, XO and its complexes adsorbed has been proposed for heavy metals determination. In the present work we have studied the adsorption of DFCd, XO and its complexes onto nonfunctionalized and functionalized by highly molecular weight quaternary ammonium salts silica surface. The conditions of these compounds immobilization were optimized. The nature of reagents binding with the surface was found by adsorption, UV/VIS and IR-spectroscopy methods. The chemical-analytical properties of solid-phase DFCd and XO were examined. The silica modified by DFCd and complex of XO with Fe(III) have proved to be more selective solid-phase reagents for sorption-spectroscopic and visual test determination of Hg (II), Pb(II) and Zn (II) at MAC level in natural water and some foodstuffs. Key words: adsorption, Xylenol Orange, 1,5-Diphenylcarbazide, heavy metal determination |
