Determination of lead in water using amberlite XAD-2 functionalized with xylenol orange resin as column material for on-line flow injection-flame atomic absorption spectrometry analysis

Abstract

A solid phase extraction (SPE) method combined with flow injection (FI) on-line flame atomic absorption spectrometry (FAAS) for the determination of lead in water samples is presented. Amberlite XAD-2, functionalized with xylenol orange resin, was synthesized by covalent coupling of the ligand with the copolymer through an azo group. A minicolumn packed with this resin was connected to the automated on-line preconcentration system. Elution of the metal ions from the minicolumn was performed using 0.1 mol L -1 nitric acid solution. The calibration graph obtained was linear over the concentration range of 0-250 μg L -1. The sorption capacity of the functionalized resin was found to be 210 μmol g -1 of dry resin. A detection limit of 1.058 μg L -1 was achieved at a sample throughput of 36 h -1. An enrichment factor (EF) of 22 was obtained over conventional flame AAS analysis. Spike recovery studies in water samples were performed using a NIST certified Pb(II) nitrate solution to confirm the accuracy of the proposed preconcentration procedure.