Solid phase extraction and determination of ultra trace amounts of copper(II) using octadecyl silica membrane disks modified by 11-hydroxynaphthacene-5,12-quinone and flame atomic absorption spectrometry

A simple and selective method for rapid extraction and determination of tra ce amounts of copper(II) ions using octadecyl-bonded silica membrane disks modified with 11-hydroxynaphthacene-5, 12-quinone and flame atomic absorpti on spectrometry is presented. Extraction efficiency and the influence of pH , flow rates, amount of ligand and type and least amount of stripping acid were evaluated. Maximum capacity of the membrane disks modified by 5 mg of the ligand was found to be 360 mug of Cu2+ ion. The break through volume is larger than 2000 ml. The limit of detection of the proposed method is 0.2 ng ml(-1). The effects of various cationic interferences on the percent rec overy of copper in binary mixtures were studied. The method was applied to the recovery of Cu2+ ions from four different water samples and a synthetic sample. (C) 2001 Elsevier Science B.V. All rights reserved.