DETERMINATION OF COPPER, NICKEL, ZINC, COBALT AND MANGANESE IN SEAWATER BY CHELATION ION CHROMATOGRAPHY

Preconcentration and determination of trace elements in seawater by ch elation ion chromatography (CIC) was studied. For the retention of met al ions (0.25-0.30 M), ammonium acetate (at pH 4.8-5.1) and macroporou s iminodiacetate chelating resin were used, This system (CIC) permits trace and ultra-trace determination of metals in a variety of complex matrices, in particular those with a high content of alkali and alkali ne earth metals. Detection limits range from 0.1 to 0.5 ng. Satisfacto ry results are obtained in the range 0.05-0.5 mug/l when 60 ml of samp le are preconcentrated. In this work the contents of zinc, copper, nic kel, cobalt and manganese in seawater from the Venice lagoon are prese nted. The results obtained by chelation ion chromatography are compare d with those obtained using preconcentration of metals with dithizone and ammonium pyrrolidinedithiocarbamate in chloroform and analysed by graphite furnace atomic absorption spectrometry.