Analyse systematique des elements traces dans l'eau de mer par activation neutronique

The trace elements in sea water, particularly the pollutant elements (Cu, Cd, As, Zn, Hg and Cr) are present in very low concentrations (in the order of 10^?9 g/ml). For the determination of the concentration of these elements the neutron activation analysis has been used successfully. The separation of the impurities has been studied using radioactive tracers by coprecipitation with carriers and on ion exchange resins. The preconcentration technics applied before the irradiation introduces too large “blank” values, which can be reduced by etching the containers with HF—EDTA. In order to have representative samples, the water must be quickly frozen after taking out from the sea. With these precautions, the method developed allows to analyse samples of 3 ml volumes. The results of sea water sample analyses from different areas are presented.