Chloromethylated polystyrene polymer (CMSP) modified with 2-mercabtobenzothiazole (MBT) has been developed for the selective separation and/or preconcentration of silver. The modified polymer (CMS-MBT) was characterized by elemental analysis and IR spectra. Batch and column modes were applied. The newly designed polymer quantitatively sorbed Ag+ at pH 2 when the flow rate is 5 ml min(-1). The maximum sorption capacity was 0.493 mmol g(-1) while the preconcentration factor was 250 for Ag+. The detection limit was 8 ng ml(-1). The desorption was effective with 5 ml of 2 mol l(-1) HNO3 prior to detection using AAS. The modified polymer was highly ion-selective in nature even in the presence of large concentrations of electrolytes or organic media, with a preconcentrating ability for Ag+. The utility of the modified polymer to synthetic and drugs samples showed RSD values of <3% reflecting its accuracy and reproducibility. (C) 2009 Elsevier B.V. All rights reserved.