Schiff base immobilized silica gel framework as an efficient sorbent forpreconcentration of Pb and Zn ions in aqueous media

Abstract

A novel preconcentration method for Pb and Zn ions using a column packed with Schiff base modi ed silica gelis described. The method was based on the sorption of analytes on N,N'-bis(4-methoxysalicylidene)-1,3-propanediaminemodi ed silica gel and elution with HNO3prior to ame atomic absorption analysis. The parameters pH, ow rate,sample volume, eluent volume, and concentration were optimized using a central composite design. The detection limitswere 10.0 g L1for Pb and 1.1 g L1for Zn. The suggested procedure was validated with Lake Ontario water asa certi ed reference material and recovery percentages were 101.8% for Pb and 98.2% for Zn. The application of themethod was performed on snow, tap, bottled, mineral, and lake water samples and recovery percentages were in therange of 96.7%{101.6% and 96.4%{98.4% for Pb(II) and Zn(II), respectively.