Several new chelating resins prepared from macroporous chloromethylated polystyrene-co-divinylbenzene by either direct attachment of the heterocyclic functional groups, such as 2-aminopyridine, 2-amino-5-methylthio-1,3,4-thiadizole, 2-amino-5-ethyl-1,3,4-thiadizole, and 2-mercaptobenzothiazole, to the polymeric matrix or through different hydrophilic spacer arms were tested for the adsorption properties toward Hg2+, Ag+, Cd2+, and Pb2+ in an ammonium acetate buffer solution of pH 3.0. The results show that these resins exhibited a high affinity for Hg2+ and Ag+. The introduction of hydrophilic spacer arms between the polymeric matrix and heterocyclic functional groups resulted in an increase in the hydrophilicity and adsorption capacity of the resins. The presence of spacer arms made the kinetics of adsorption faster. The influence of the length of the spacer arm on the adsorption properties was also investigated. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 2148-2156, 2009