XAD copolymer resins may be functionalized with heavy metal ion-selective ligands either by covalent linkage to the polymer backbone or by
impregnation. These resins may be tailored to be specific for certain heavy metals by adjusting the adsorption and elution parameters, thereby
enabling simple and cost-effective spectrophotometric and flame atomic absorption spectrometry (FAAS) determinations of these metals
without requiring the more sophisticated coupled instrumental techniques. For the synthesis of o-aminobenzoic acid (ABA)-immobilized
XAD-4 copolymer resin that is expected to preconcentrate a number of transition and heavy metals, the azo-linkage method was chosen.
For this purpose the copolymer was nitrated, reduced to the corresponding amine, converted to the diazonium salt with nitrite, and reacted
with o-aminobenzoic acid to produce the XAD-ABA sorbent. This sorbent was capable of preconcentrating Pb(II), Cd(II), Ni(II), Co(II) and
Zn(II) from weakly acidic or neutral aqueous solution. The retained metals were eluted with 1.0 M HNO3 from the resin column, and were
subsequently determinated with by flame atomic absorption spectrometry. The developed resin preconcentration and determination method
was successfully applied to the analysis of a synthetic metal mixture solution, a certified reference material (CRM) of coal sample, and
brackish lake water