Highly effective solid phase extraction of some heavy metal ions using a cartridge filled with imprinted silica-supported N4O4 type bis(diazoimine) ligands

摘要

New silica-supported N4O4 type bis(diazoimine) ligands were synthesized and characterized successively. In the synthesis stages, diazotized cations of 1,5-diaminonaphthalene and 3,3'-dimethyIbiphenyl-4,4'-diamine (o-tolidine) were coupled with 2,4-dihydroxybenzaldehyde to give bis(diazocarbonyl) compounds; (A1: 5,5'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(diazene-2,1-diyI)bis(2,4-dihydroxybenzalde-hyde)) and A2: 5,5'-(3,3'-dimethilbifenil-4,45,5'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(diazene-2,1-diyI)-bis(2,4-dihydroxybenzaldehyde). Then, &ts(diazocarbonyl) compounds were chemically supported to armno-modified silica-gel particles and the obtained silica-supported 6is(diazoimine) ligands (L1, L2). All the synthesized compounds were characterized by using elemental analysis, MS (ESI), liquid phase NMR (~1H and ~(13)C) and solid phase NMR (~(29)Si and ~(13)C CP MAS), FT-IR, TG/DTA, photoluminescence, SEM and EDX techniques. The electrochemical properties of fc(diazocarbonyl) compounds (A1,A2) were investigated by cyclic voltammetry technique. Optimum extraction parameters of the synthesized sor-bents were determined for syringe and batch techniques by using ICP-OES. At optimum conditions, the recoveries of Pb(II), Cu(II), Cd(II) and Cr(III) were 95-99% with relative standard deviations (RSDs) of ±2-3%. All the multifunctional silica-supported ligands showed highly effective solid phase extraction properties. They are reliable, feasible, easy to use and satisfactory evidently even for real water samples.