SYNTHESIS, PROPERTIES AND APPLICATIONS OF SILICA-IMMOBILIZED 8-QUINOLINOL .2. ONLINE COLUMN PRECONCENTRATION OF COPPER, NICKEL AND CADMIUM FROM SEA-WATER AND DETERMINATION BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

The coupling of an on-line column preconcentration manifold with continuous flow ultrasonic nebulizer equipped with a desolvation system for simultaneous determination of metal ions by inductively coupled plasma atomic emission spectrometry (ICP-AES) is described. The silica-immobilized 8-quinolinol prepared by an improved synthetic route has been evaluated as a preconcentration material for metals in a flow system. Dynamic exchange capacities of this material were ascertained by determining the breakthrough volumes of radiotracer Cu-64 solution under different flow parameters. Optimization of the on-line column preconcentration with ICP-AES measurement was investigated. The feasibility of the proposed method was tested for the determination of Cu, Ni and Cd in open sea water samples. Results obtained for the determination of these elements in NASS-2 sea water sample agreed very well with certified values. The limits of detection based on a sample volume of 25 mi for Cu, Ni and Cd were 0.07, 0.054 and 0.016 ng ml(-1), respectively.