Application of chitosan functionalized with 8-hydroxyquinoline:: Determination of lead by flow injection flame atomic absorption spectrometry

This work describes the application of chitosan - chemically modified with 8-hydroxyquinoline - in a simple and efficient preconcentration system using flow injection flame atomic absorption spectrometry (FI-FAAS) for the determination of Pb2+ ions. The efficiency of the chelating resin and the accuracy of the proposed method were evaluated by the metal ion recovery technique in samples of mineral water, potable water and lake water. The recovery of Pb2+ ions from spiked solutions was less than 70% due to matrix effects, which were eliminated by addition of Ba2+ metal ions, resulting in recoveries of approximately 100% for all water samples. Ag+, Cd2+, Cu2+, Mn2+, Ni2+, Zn2+, Hg2+, Ca2+, Mg2+, Cr3+, Al3+ and Fe3+ metal ions were studied with respect to their interference with Pb2+ metal ion determination, and the chelating resin exhibited high selectivity for Pb2+ at pH 7. The analytical properties of merit were obtained using the parameters previously optimized. The method shows high precision with a relative standard deviation ( R. S. D.) of 1.1% (n = 7) for a solution containing 50 mu gL(-1) of Pb2+ and a detection limit ( L. O. D.) of 1.7 mu gL(-1).