Design, Synthesis and Application of Chemically Modified Amberlite XAD‐2 for Separation and Preconcentration of Pb(II)

Abstract

AbstractA highly selective, efficient, green analytical method was developed to separate and preconcentrate trace amounts of lead from aqueous samples using gallic acid‐immobilized Amberlite XAD‐2. The method was designed by determining the stability constant of the Pb‐GA complex and plotting the chemical speciation diagram, which indicated strong complexation of Pb(II) with GA (log βPb‐GA=9.50). The species distribution curve for the Pb‐GA complex indicates almost 98 % complexation, forming Pb‐GA as the predominant species. Considering the strong interaction of GA toward the lead, GA was immobilized on the polymeric matrix of Amberlite XAD‐2, and the conditions for the uptake of lead from the aqueous solutions were optimized by both batch and column methods. The sorption capacity and concentration factor of modified Amberlite XAD‐2 for Pb(II) were found to be 4554 μg g−1 and100 respectively. The method was employed for the determination of lead in various wastewater samples. Molecular modeling studies were also performed on GA‐immobilized Amberlite XAD‐2 to determine the active structure of GA on the surface.