Silica polyamine composites have been modified with chelating ligands for the purpose of selective extraction of heavy metals from aqueous media. The adsorption properties of modified composites have been determined for divalent and trivalent metal ions. Selective extraction and recovery from media containing multiple metal ions has been demonstrated. The distinct advantages of incorporating polyamines relative to silica funtctionalized with propyl amines have been clearly demonstarted. Substantial improvements in composite performance have resulted from structural modification. A large molar fraction of the silanizing agent chloropropyl trichlorosilane (CPTCS) has been substituted with methyl trichlorosilane. Notable increases in silane surface coverage have been determined by solid state NMR and elemental analysis. Modification of the polymer amine sites of these mixed silane composites with chelating groups has resulted in improved metal ion capacities relative to those composites with CPTCS only.