Determination of Trace Amounts of Silver in Natural Waters by FAAS After Sorption on Octadecyl Silica Membrane Disks Modified with Tetramethyl Tetraselena Fulvalene

A simple, highly sensitive, accurate, and selective method for the determination of trace amounts of ag+ ions in water samples is proposed. the method is based on the separation and preconcentration of ag+ on an octadecyl-bonded silica membrane disk modified by arecently synthesized schiff base tetramethyl tetraselena fulvalene (tmtsf) at ph 7. the synthesis of this extractant ligand is also described. the retained silver on the membrane waseluted with 2x5 ml 0.5 m rn03 and measured by flame atomic absorption spectrometry(faas) at 232.0 nm. the extraction efficiency and the influence of the type and least amountof eluent for the stripping of ag+ from the disks, ph, flow rates of sample solution and eluent, amount of tmtsf, effect of other ions, and breakthrough volume were evaluated.the maximum capacity of the membrane disks modified by 3 mg oftmtsf was found tobe 146 ± 4 (mu)g ag+. the 3cr limit of detection of the method was 30 ng per 1000 ml and also an enrichment factor of 250 was obtained. the proposed method has been applied for the determination of silver in several water samples with satisfactory results .