Octadecyl Silica Membrane Disks Modified with a New Schiff's Base for the Preconcentration of Lead and Copper before Their Determination in Water Samples

A simple and fast method for the extraction and determination of ppt level of Pb2+ and Cu2+ ions using octadecyl‐bonded silica membrane disks modified by a new tetradentates Schiff's base [Bis(2, 4‐dimethoxy benzaldehyde) ethylen diimine](TDSB) and inductively coupled plasma atomic emission spectrometry is described. Extraction efficiency, and influence of flow rate, pH, type and the least amount of acid for stripping of Cu2+ and Pb2+ from the modified disks and break through volume were evaluated. The maximum capacity of the membrane disks modified by 5 mg of TDSB used was found to be 347±7 and 470±6 μg of copper and lead, respectively. The concentration factor is 500 (for 2500 mL water sample and flow rate of 20 mL min‐1) and detection limit of the proposed method is 12.5 and 150.5 pg/ml for Cu2+and Pb2+, respectively. The method was applied to the determination of Cu2+ and Pb2+ ions from various water, wastewater, black tea, and hot pepper samples.