On-line preconcentration and determination of trace elements in waters and reference cereal materials by flow injection - FAAS using newly synthesized 8-hydroxy-2-quinoline carboxaldehyde functionalized Amberlite XAD-4

Abstract

A new chelating resin has been developed using Amberlite XAD-4 resin anchored with 8-hydroxy-2-quinoline carboxaldehyde through -C=N- group. The synthesized resin, characterized by infrared spectroscopy, was used as packing for the minicolumn in an on-line preconcentration system for cadmium, cobalt, copper, lead, manganese and nickel (Cd, Co Cu, Pb, Mn and Ni) determination. Metal ions retained on the modified resin were eluted using 1.0 mol L-1 HNO3 solution and aspirated directly to the nebulizer-burner system of a FAAS instrument using a flow injection system. Optimum hydrodynamic and chemical conditions for metal sorption were investigated. Detection limits (3 sigma-) were determined to be 0.14 mu g L-1 for Cd, 0.35 mu g L-1 for Cu, 0.26 mu g L-1 for Mn, 0.70 mu g L-1 for Co, 0.72 mu g L-1 for Ni and 2.92 mu g L-1 for Pb using a 10 mL sample loading. Enrichment factors for Cu(II), Mn(II), Co(II), Pb(II), Ni(II) and Cd(II) were found to be 22.3, 24.7, 23.2, 24.1, 20.2 and 27.6, respectively. The proposed method was successfully applied to the determination of analytes in water samples, and in food samples such as cereal certified reference materials.