A simultaneous preconcentration and separation method for determination of trace amount of dissolved Ag+, Pb2+ and Pd2+ ions by modified octadecyl silica membrane disks with DBzDA18C6 was developed. The adsorbed metal complexes were eluted from disk with 10 mL of 4 M KCl and determined by flame atomic absorption spectroscopy. Several parameters such as anion effect, pH of sample solution, type of eluent, amount of ligand, sample and elution flow rate were evaluated. The effect of diverse ions on preconcentration was also investigated. A precocentration factor of 110 can easily be achieved depending on the volume of the sample. For 100 mL of the solution the linear dynamic rang were found to be 30–1000, 140–6000, 60–900 g l-1 for Ag+, Pb2+ and Pd2+, respectively. Based on three standard deviation of the blank the detection limit was obtained as 1.8, 8.0 and 4.2 g L-1 for Ag+, Pb2, Pd2, respectively. The formation constants of Ag+ and Pb2+ ions with DBzDA18C6 at 25 C were determined from the molar conductance–mole ratio data. This method was applied for the determination of Ag+, Pb2+ and Pd2+ in environmental water, tea and soil samples
